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Human Activities are Contributing to Global Carbon Dioxide Levels, but Possibly not in the Way You Think They Are

The Human Development Index (HDI), which is a measure of the quality of life, was developed in 1990 by the United Nations to enable cross-national comparisons of the state of human development. You can read about the HDI and download the UN’s annual Human Development Reports at the following link:

http://hdr.undp.org

As you might imagine, there are large HDI differences among the world’s many nations. In its 2016 Human Development Report, the following nations were at the top and bottom of the HDI international ranking:

  • The top five places in the global HDI rankings are: Norway (0.949), Australia (0.939), Switzerland (0.939), Germany (0.926) with Denmark and Singapore (0.925) sharing the 5th spot.
  • The bottom five countries in rank order of HDI are: Burundi (0.404), Burkina Faso (0.402), Chad (0.396), Niger (0.353) and Central African Republic (0.352).

The UN reported that the regional HDI trends from 1990 to 2015 are up in all regions of the world, as shown in the following figure.

The U.S. Department of Energy (DOE) developed a general correlation between HDI and the annual per capita energy consumption in each nation, as shown in the following figure. Note that annual per capita energy consumption is not a factor in the UN’s determination of HDI.

Source: DOE “Nuclear Energy Research & Development Roadmap – Report to Congress”,     April 2010

DOE reports:

“Figure 3 illustrates that a nation’s standard of living depends in part on energy consumption. Access to adequate energy is now and will continue to be required to achieve a high quality of life.”

Based on the 25-year HDI trends reported by the UN (Figure 1.1, above), nations generally have been moving up the HDI scale. Based on the DOE correlation (Figure 3, above), many of these nations, especially the least-developed nations, also should be moving up the scale for per capita energy consumption (to the right in the chart above) as their HDI increases. The net result should be a worldwide trend toward higher median per capita energy consumption. While conservation efforts may help reduce the per capita energy consumption in highly developed nations, there is a large fraction of the world’s population living in less developed nations. In these countries the per capita energy consumption will grow significantly as the local economies develop and the local populations demand basic goods and services that are commonplace in more developed nations.

In his commentary on global warming, Nobel laureate Dr. Ivar Giaever takes issue with CO2 being the cause of global warming by noting that the key “evidence” is a claimed global average temperature increase of 0.8 degrees (288 to 288.8 K) between 1880 and 2013 and a supposed correlation of this temperature increase with the increase of CO2 in the atmosphere. Dr. Giaever takes the position that measuring a worldwide average temperature trend is a difficult task, particularly with the modest number of measurement points available more than a hundred years ago, the consistency of measurement over the period of interest, and the still-modest number of measurement points in many parts of the world today. In addition, he notes that a 0.8 degree K change in worldwide average temperature over a period of 133 years seems to be a very high level of consistency rather than an alarming trend. During that same period, Dr. Giaever noted that world population increased from 1.5 to 7 billion and many human activities contributed to environmental change, yet the impacts of all these additional people are rarely mentioned in the climate change debate. You can watch one of Dr. Giaever lectures at the following link:

https://www.youtube.com/watch?v=SXxHfb66ZgM

What is the impact of having 5.5 billion more people in the world today (and their many ancestors for the past 133 years) on global CO2 emissions? That’s hard to determine, but a simpler starting point is to assess the impact of one additional person.

That matter was addressed in a 2017 article by Seth Wynes and Kimberly Nicholas entitled, “The climate mitigation gap: education and government recommendations miss the most effective individual actions,” which was published in Environmental Research Letters. The authors developed a ranking for a wide variety of human activities relative to their contribution to CO2 emission reduction measured in tonnes (metric tons, 2205 pounds) of CO2-equivalent per year. I can tell you that the results are surprising.

A synopsis of these results is published in The Guardian using the following simple graphic.

The study authors, Wynes and Nicholas, concluded:

“We recommend four widely applicable high-impact (i.e. low emissions) actions with the potential to contribute to systemic change and substantially reduce annual personal emissions: having one fewer child (an average for developed countries of 58.6 tonnes CO2-equivalent (tCO2e) emission reductions per year), living car-free (2.4 tCO2e saved per year), avoiding airplane travel (1.6 tCO2e saved per roundtrip transatlantic flight) and eating a plant-based diet (0.8 tCO2e saved per year). These actions have much greater potential to reduce emissions than commonly promoted strategies like comprehensive recycling (four times less effective than a plant-based diet) or changing household lightbulbs (eight times less).”

Surprise!! Population growth adds CO2 to the atmosphere and the biggest impact a person can have on their own carbon footprint is to not have an additional child.

The authors noted that average savings of 58.6 tCO2e per year for having one fewer child applies to developed countries, where we expect per-capita energy consumption to be high. In less developed nations, where we expect lower per-capita energy consumption, the average savings for having one fewer child will be smaller. However, as their HDI continues to increase, the per-capita energy consumption in less developed nations eventually will rise and may approach the values occurring now in medium- or high-developed countries.

You can read the synopsis of the Wynes and Nicholas analysis in The Guardian here:

https://www.theguardian.com/environment/2017/jul/12/want-to-fight-climate-change-have-fewer-children

You can read the full paper in Environmental Research Letters here:

http://iopscience.iop.org/article/10.1088/1748-9326/aa7541

The mathematical approach for estimating the CO2-equivalent per year of an additional child is based on a 2009 paper by Paul A. Murtaugh and Michael G. Schlax entitled, “Reproduction and the carbon legacies of individuals,” and published in Global Environmental Change. The authors state:

“Here we estimate the extra emissions of fossil carbon dioxide that an average individual causes when he or she chooses to have children. The summed emissions of a person’s descendants, weighted by their relatedness to him, may far exceed the lifetime emissions produced by the original parent.”

“It is important to remember that these analyses focus on the carbon legacies of individuals, not populations. For example, under the constant-emission scenario, an extra child born to a woman in the United States ultimately increases her carbon legacy by an amount (9441 metric tons) that is nearly seven times the analogous quantity for a woman in China (1384 tons), but, because of China’s enormous population size, its total carbon emissions (from its human population) currently exceed those of the United States.”

“…..ignoring the consequences of reproduction can lead to serious under-estimation of an individual’s long-term impact on the global environment.”

You can read this complete paper here:

https://www.biologicaldiversity.org/programs/population_and_sustainability/pdfs/OSUCarbonStudy.pdf

How’s your carbon legacy doing?

How to Build a Nuclear-Powered Aircraft Carrier

The latest U.S. nuclear-powered aircraft carrier, USS Gerald R. Ford (CVN-78), is the first of a new class (the Ford-class) of carriers that is intended to replace the already-retired USS Enterprise (CVN-65) and all 10 of the Nimitz-class carriers (CVN-68 to CVN-77) as they retire after 49 years of service between 2024 to 2058. Newport News Shipbuilding (NNS), a Division of Huntington Ingalls Industries, built all U.S. nuclear-powered aircraft carriers and is the prime contractor for the Ford-class carriers.

USS Gerald R. Ford (CVN-78) was authorized in fiscal year 2008. Actual construction took almost four years from keel laying on 13 November 2009 to launching on 11 October 2013. NNS uses a modular construction process to build major subassemblies in industrial areas adjacent to the drydock and then move each modular unit into the drydock when it is ready to be joined to the rapidly growing structure of the ship.

Overview of the NNS shipyard and CVN-78 in January 2012. Source: Newport News Shipbuilding / Chris OxleyCVN-78 under construction in the NNS drydock. Source: Newport News Shipbuilding

NNS created a short video of an animated 3-D model of CVN-78 showing the arrival and placement of major modules during the 4-year construction period. Highlights are shown in the screenshots below, and the link to the NNS animated video is here:

http://nns.huntingtoningalls.com/employees/pub/media/videos/cvn78_build.mp4

CVN-78 construction sequence highlights. Source: composite of 10 screenshots from a Newport News Shipbuilding video.

You also can watch a time-lapse video of the 4-year construction process from keel laying to christening here:

http://nns.huntingtoningalls.com/employees/pub/watch/cvn78-timelapse-4years.html

In this video, you’ll see major subassemblies, like the entire bow structure and the island superstructure moved into place with heavy-lift cranes.

CVN-78 lower bow unit being moved into place in 2012. Source: Newport News Shipbuilding / Ricky ThompsonCVN-78 “island” superstructure being moved into place. Source: Newport News Shipbuilding

After launching, another 3-1/2 years were required for outfitting and testing the ship dockside, loading the two Bechtel A1B reactors, and then conducting sea trials before the ship was accepted by the Navy and commissioned in July 2017.

CVN-78 underway. Source: U.S. Navy

Since commissioning, the Navy has been conducting extensive operational tests all ship systems. Of particular interest are new ElectroMAgnetic Launch System (EMALS) and the electro-mechanical Advanced Arresting Gear (AAG) system that replace the traditional steam catapults and hydraulic arresting gear on Nimitz-class CVNs. If all tests go well, USS Gerald R. Ford is expected to be ready for its first deployment in late 2019 or early 2020.

So, how much did it cost to deliver the USS Gerald R. Ford to the Navy? About $12.9 B in then-year (2008) dollars, according Congressional Research Service (CRS) report RS-20643, “Navy Ford (CVN-78) Class Aircraft Carrier Program: Background and Issues for Congress,” dated 9 August 2017. You can download this CRS report here:

https://fas.org/sgp/crs/weapons/RS20643.pdf

Milestones for the next two Ford-class carriers are summarized below:

  • CVN-79, USS John. F. Kennedy: Procured in FY 2013; scheduled for delivery in September 2024 at a cost of $11.4 B in then-year (2013) dollars.
  • CVN-80: USS Enterprise: To be procured in FY 2018; scheduled for delivery in September 2027 at a cost of about $13 B in then-year (2018) dollars.

To recapitalize the entire fleet of 10 Nimitz-class carriers will cost more than $130 B by the time the last Nimitz-class CVN, USS George H.W. Bush, is scheduled to retire in 2058 and be replaced by a new Ford-class CVN.

The current Congressional mandate is for an 11-ship nuclear-powered aircraft carrier fleet. On 15 December 2016, the Navy presented a new force structure assessment with a goal to increase the U.S. fleet size from the currently authorized limit of 308 vessels to 355 vessels. The Heritage Foundation’s 2017 Index of U.S. Military Strength reported that the Navy’s actual fleet size in early 2017 was 274 vessels, so the challenge of re-building to a 355 ship fleet is much bigger than it may sound, especially when you account for the many planned retirements of aging vessels in the following decades. The Navy’s Force Structure Assessment for a 355-ship fleet includes a requirement for 12 CVNs. The CRS provided their commentary on the 355-ship fleet plans in a report entitled, “Navy Force Structure and Shipbuilding Plans: Background and Issues for Congress,” dated 22 September 2017. You can download that report here:

https://fas.org/sgp/crs/weapons/RL32665.pdf

As the world’s political situation continues to change, there may be reasons to change the type of aircraft carrier that is procured by the Navy. Rand Corporation provided the most recent assessment of this issue in their 2017 report entitled, “ Future Aircraft Carrier Options.” The Assessment Division of the Office of the Chief of Naval Operations sponsored this report. You can download this report at the following link:

https://www.rand.org/pubs/research_reports/RR2006.html

So, how many Ford-class aircraft carriers do you think will be built?

Linking Gravitational Wave Detection to the Rest of the Observable Spectrum

The Laser Interferometer Gravitational-Wave Observatory (LIGO) in the U.S. reported the first ever detection of gravitational waves on 14 September 2015 and, to date, has reported three confirmed detections of gravitational waves originating from black hole coalescence events. These events and their corresponding LIGO press releases are listed below.

  • GW150914, 14 September 2015

https://www.ligo.caltech.edu/page/press-release-gw150914

  • GW151226, 26 December 2015

https://www.ligo.caltech.edu/page/press-release-gw151226

  • GW170104, 4 January 2017

https://www.ligo.caltech.edu/page/press-release-gw170104

The following figure illustrates how these black hole coalescence events compare to our knowledge of the size of black holes based on X-ray observations. The LIGO team explained:

“LIGO has discovered a new population of black holes with masses that are larger than what had been seen before with X-ray studies alone (purple). The three confirmed detections by LIGO (GW150914, GW151226, GW170104), and one lower-confidence detection (LVT151012), point to a population of stellar-mass binary black holes that, once merged, are larger than 20 solar masses—larger than what was known before.”

Image credit: LIGO/Caltech/MIT/Sonoma State (Aurore Simonnet)

On 1 August 2017, the Advanced VIRGO detector at the European Gravitational Observatory (EGO) in Cascina, Italy (near Pisa) became operational, using wire suspensions for its interferometer mirrors instead of the fragile glass fiber suspensions that had been delaying startup of this detector.

On 17 August 2017, the LIGO – VIRGO team reported the detection of gravitational waves from a new source; a collision of two neutron stars. In comparison to black holes, neutron stars are low-mass objects, yet the neutron star collision was able to generate gravitational waves that were strong enough and in the detection frequency range of the LIGO and VIRGO. You’ll find the LIGO press release for that event, GW170817, at the following link.

https://www.ligo.caltech.edu/page/press-release-gw170817

The following figure from this press release illustrates the limits of localizing the source of a gravitational wave using the gravitational wave detectors themselves. The localization of GW180817 was much better than the previous gravitational wave detections because the detection was made by both LIGO and VIRGO, which have different views of the sky and a very long baseline, allowing coarse triangulation of the source.

Gravitational wave sky map. Credit__LIGO_Virgo_NASA_Leo_Singer__Axel_Melli

Unlike the previous gravitational wave detections from black hole coalescence, the neutron star collision that produced GW180817 also produced other observable phenomena. Gravitational waves were observed by LIGO and VIRGO, allowing coarse localization to about 31 square degrees in the sky and determination of the time of the event. The source of a two-second gamma ray burst observed at the same time by the Fermi and INTEGRAL gamma ray space telescopes (in Earth orbit) overlapped with the region of the sky identified by LIGO and VIRGO. An optical transient (the afterglow from the event) in that overlap region was first observed hours later by the 1 meter (40 inch) Swope Telescope on Cerro Las Campanas in Chile. The results of this localization process is shown below and is described in more detail in the following LIGO press release:

https://www.ligo.caltech.edu/news/ligo20171016

The sky map created by LIGO-Virgo (green) showing the possible location of the source of gravitational waves, compared with regions containing the location of the gamma ray burst source from Fermi (purple) and INTEGRAL (grey). The inset shows the actual position of the galaxy (orange star) containing the “optical transient” that resulted from the merger of two neutron stars (Credit: NASA/ESO)

The specific source initially was identified optically as a brilliant blue dot that appeared to be in a giant elliptical galaxy. A multi-spectral “afterglow” persisted at the source for several weeks, during which time the source became a dim red point if light. Many observatories were involved in detailed observations in the optical and infra-red ranges of the spectrum.

Important findings relate to the formation of large quantities of heavy elements (i.e., gold to uranium) in the aftermath of this event, which is known as a “kilonova.” This class of events likely plays an important role in seeding the universe with the heaviest elements, which are not formed in ordinary stars or novae. You’ll find more details on this matter in Lee Billing’s article, “Gravitational Wave Astronomers Hit the Mother Lode,” on the Scientific American website at the following link:

https://www.scientificamerican.com/article/gravitational-wave-astronomers-hit-mother-lode1/

The ability to localize gravitational wave sources will improve as additional gravitational wave detectors become operational and capabilities of existing detectors continue to be improved. The current status of worldwide gravitational wave detector deployment is shown in the following figure.

Source: LIGO

The ability to take advantage of “multi-messenger” (multi-spectral) observations will depend on the type of event and timely cueing of observatories worldwide and in orbit. The success of the GW170817 detection and subsequent multi-spectral observations of “kilonova” demonstrates the rich scientific potential for such coordinated observations

 

Significant Progress has Been Made in Implementing the Arctic Council’s Arctic Marine Strategic Plan (AMSP)

The Arctic Council describes itself as, “….the leading intergovernmental forum promoting cooperation, coordination and interaction among the Arctic States, Arctic indigenous communities and other Arctic inhabitants on common Arctic issues, in particular on issues of sustainable development and environmental protection in the Arctic.” The council consists of representatives from the eight Arctic states:

  • Canada,
  • Kingdom of Denmark (including Greenland and the Faroe Islands)
  • Finland
  • Iceland
  • Norway
  • Russia
  • Sweden
  • United States

In addition, six international organizations representing Arctic indigenous people have permanent participant status. You’ll find the Arctic Council’s website at the following link:

http://www.arctic-council.org/index.php/en/

One outcome of the Arctic Council’s 2004 Senior Arctic Officials (SAO) meeting in Reykjavik, Iceland was a call for the Council’s Protection of the Arctic Marine Environment (PAME) working group to conduct a comprehensive Arctic marine shipping assessment as outlined in the AMSP. The key result of that effort was The Arctic Marine Shipping Assessment 2009 Report (AMSA), which you can download here:

https://oaarchive.arctic-council.org/handle/11374/54

Source: Arctic Council

This report provided a total of 17 summary recommendations for Arctic states in the following three areas:

I. Enhancing Arctic marine safety

A. Coordinating with international organizations to harmonize a regulatory framework for Arctic maritime safety.

B. Supporting International Maritime Organization (IMO) standards for vessels operating in the Arctic.

C. Developing uniform practices for Arctic shipping governance, including in areas of the central Arctic ocean that are beyond the jurisdiction of any Arctic state.

D. Strengthening passenger ship safety in Arctic waters

E. Supporting development of a multi-national Arctic search and rescue capability.

II. Protecting Arctic people and the environment

A. Conducting surveys of Arctic marine use by indigenous people

B. Ensuring effective engagement with Arctic coastal communities

C. Identifying and protecting areas of heightened ecological and cultural significance.

D. Where appropriate, designating “Special Areas” or “Particularly Sensitive Areas”

E. Protecting against introduction of invasive species

F. Preventing oil spills

G. Determining impacts on marine animals and take mitigating actions

H. Reducing air emissions (CO2, NOx, SO2 and black carbon particles)

III. Building the Arctic marine infrastructure

A. Improving the Arctic infrastructure to support development while enhancing safety and protecting the Arctic people and environment, including icebreakers to assist in response.

B. Developing a comprehensive Arctic marine traffic awareness system and cooperate in development of national monitoring systems.

C. Developing a circumpolar environmental response capability.

D. Investing in hydrographic, meteorological and oceanographic data needed to support safe navigation and voyage planning.

The AMSA 2009 Report is a useful resource, with thorough descriptions and findings related to the following:

  • Arctic marine geography, climate and sea ice
  • History of Arctic marine transport
  • Governance of Arctic shipping
  • Current marine use and the AMSA shipping database
  • Scenarios, futures and regional futures to 2020 (Bering Strait, Canadian Arctic, Northern Sea Route)
  • Human dimensions (for a total Arctic population of about 4 M)
  • Environmental considerations and impacts
  • Arctic marine infrastructure

Four status reports from 2011 to 2017 documented the progress by Arctic states in implementing the 17 summary recommendations in AMSA 2009. The fourth and final progress report entitled, “Status of Implementation of the AMSA 2009 Report Recommendations; May 2017,” is available at the following link:

https://www.isemar.fr/wp-content/uploads/2017/09/Conseil-de-Arctic-rapport-Arctic-Marine-Shipping-Assessment-AMSA-mai-2017.pdf

Source: Arctic Council

Through PAME and other working groups, the Arctic Council will continue its important role in implementing the Arctic Marine Strategic Plan. You can download the current version of that plan, for the period from 2015 – 2025, here:

https://oaarchive.arctic-council.org/handle/11374/413

Source: Arctic Council

For example, on 6 November 2017, the Arctic Council will host a session entitled, “The global implications of a rapidly-changing Arctic,” at the UN Climate Change Conference COP23 meeting in Bonn, Germany. For more information on this event, use this link:

http://www.arctic-council.org/index.php/en/our-work2/8-news-and-events/473-cop23

 

 

 

The Sad State of Affairs of the U.S. Polar Icebreaking Fleet, Revisited

In my 9 September 2015 post, I reviewed the current state of the U.S. icebreaking fleet. My closing comments were:

“The U.S. is well behind the power curve for conducting operations in the Arctic that require icebreaker support.  Even with a well-funded new U.S. icebreaker construction program, it will take a decade before the first new ship is ready for service, and by that time, it probably will be taking the place of Polar Star, which will be retiring or entering a more comprehensive refurbishment program.”

Alternatives for modernizing existing U.S. polar icebreakers to extend their operating lives and options for procuring new polar icebreakers were described in the Congressional Research Service report, “Coast Guard Polar icebreaker Modernization: Background and Issues for Congress,” dated 2 September 2015. You can download that report here:

https://news.usni.org/wp-content/uploads/2015/09/RL34391.pdf

While the Coast Guard Authorization Act of 2015 made funds available for “pre-acquisition” activities for a new polar icebreaker, little action has been taken to start procuring new polar icebreakers for the USCG. This Act required the Secretary of the Department of Homeland Security (DHS) to engage the National Academies (ironically, not the Coast Guard) in “an assessment of alternative strategies for minimizing the costs incurred by the federal government in procuring and operating heavy polar icebreakers.”

The DHS and USCG issued the “Coast Guard Mission Needs Statement,” on 8 January 2016 as a report to Congress. This report briefly addressed polar ice operations in Section 11 and in Appendix B acknowledged two key roles for polar icebreakers:

  • The USCG provides surface access to polar regions for all Department of Defense (DoD) activities and logistical support for remote operating facilities.
  • The USCG supports the National Science Foundation’s research activities in Antarctica by providing heavy icebreaking support of the annual re-supply missions to McMurdo Sound. Additionally, USCG supports the annual NSF scientific mission in the Arctic.

This report to Congress failed to identify deficiencies in the USCG polar icebreaker “fleet” relative to these defined missions (i.e., the USCG has only one operational, aging heavy polar icebreaker) and was silent on the matter of procuring new polar icebreakers. You can download the 2016 “Coast Guard Mission Needs Statement” here:

https://www.dhs.gov/sites/default/files/publications/United%20States%20Coast%20Guard%20-%20Mission%20Needs%20Statement%20FY%202015.pdf

On 22 February 2017, the USCG made some progress when it awarded five, one-year, firm fixed-price contracts with a combined value of $20 M for heavy polar icebreaker design studies and analysis. The USCG reported that, “The heavy polar icebreaker integrated program office, staffed by Coast Guard and U.S. Navy personnel, will use the results of the studies to refine and validate the draft heavy polar icebreaker system specifications.” The USCG press release regarding this modest design study procurement is here:

http://mariners.coastguard.dodlive.mil/2017/02/23/2222017-five-firm-fixed-price-contracts-awarded-for-heavy-polar-icebreaker-design-studies-analysis/

The National Academies finally issued their assessment of U.S. polar icebreaker needs in a letter report to the Secretary of Homeland Security dated 11 July 2017. The report, entitled, “Acquisition and Operation of Polar Icebreakers: Fulfilling the Nation’s Needs.” offered the following findings and recommendations:

  1. Finding: The United States has insufficient assets to protect its interests, implement U.S. policy, execute its laws, and meet its obligations in the Arctic and Antarctic because it lacks adequate icebreaking capability.
  2. Recommendation: The United States Congress should fund the construction of four polar icebreakers of common design that would be owned and operated by the United States Coast Guard (USCG).
  3. Recommendation: USCG should follow an acquisition strategy that includes block buy contracting with a fixed price incentive fee contract and take other measures to ensure best value for investment of public funds.
  4. Finding: In developing its independent concept design and cost estimates, the committee determined that the cost estimated by USCG for the heavy icebreakers are reasonable (average cost per ship of about $791 million for a 4-ship buy).
  5. Finding: Operating costs of new polar icebreakers are expected to be lower than those of the vessels they replace.
  6. Recommendation: USCG should ensure that the common polar icebreaker design is science ready and that one of the ships has full science capability. (This means that the design includes critical features and structures that cannot be cost-effectively retrofit after construction).
  7. Finding: The nation is at risk of losing its heavy icebreaking capability – experiencing a critical capacity gap – as the Polar Star approaches the end of its extended service life, currently estimated to be 3 to 7 years (i.e., sometime between 2020 and 2024).
  8. Recommendation: USCG should keep the Polar Star operational by implementing an enhanced maintenance program (EMP) until at least two new polar icebreakers are commissioned.

You can download this National Academies letter report here:

https://www.nap.edu/catalog/24834/acquisition-and-operation-of-polar-icebreakers-fulfilling-the-nations-needs

There has been a long history of studies that have shown the need for additional U.S. polar icebreakers. This National Academies letter report provides a clear message to DHS and Congress that action is needed now.

In the meantime, in Russia:

To help put the call to action to modernize and expand the U.S. polar icebreaking capability in perspective, let’s take a look at what’s happening in Russia.

The Russian state-owned nuclear icebreaker fleet operator, Rosatomflot, is scheduled to commission the world’s largest nuclear-powered icebreaker in 2019. The Arktika is the first of the new Project 22220 LK-60Ya class of nuclear-powered polar icebreakers being built to replace Russia’s existing, aging fleet of nuclear icebreakers. The LK-60Ya is a dual-draught design that enables these ships to operate as heavy polar icebreakers in Arctic waters and also operate in the shallower mouths of polar rivers. Vessel displacement is about 37,000 tons (33,540 tonnes) with water ballast and about 28,050 tons (25,450 tonnes) without water ballast. When ballasted, LK-60Ya icebreakers will be able to operate in Arctic ice of any thickness up to 4.5 meters (15 feet).

The principal task for the new LK-60Ya icebreakers will be to clear passages for ship traffic on the Northern Sea route, which runs along the Russian Arctic coast from the Kara Sea to the Bering Strait. The second and third ships in this class, Sibir and Ural, are under construction at the Baltic Shipyard in St. Petersburg and are expected to enter service in 2020 and 2021, respectively.

Arktika (on right), Akademik Lomonosov floating nuclear power plant (center), and Sibir (on left) dockside at Baltic Shipyard, St. Petersburg, Russia, October 2017: Source: Charles Diggers / maritime-executive.com

In June 2016, Russia launched the first of four diesel-electric powered 6,000 ton Project 21180 icebreakers at the Admiralty Shipyard in St. Petersburg. The Ilya Muromets, which is expected to be delivered in November 2017, will be the Russian Navy’s first new military icebreaker in about 50 years. It is designed to be capable of breaking ice with a thickness up to 1 meter (3.3 feet). The Project 21180 icebreaker’s primary mission is to provide icebreaking services for the Russian naval forces deployed in the Arctic region and the Far East. The U.S. has no counterpart to this class of Arctic vessel.

Project 21180 military icebreaker Ilya Muromets. Source: The Baltic Post

You’ll find more information on Russia’s Project 21180-class icebreakers here:

http://www.naval-technology.com/projects/project-21180-class-icebreakers/

Russia’s 7,000 – 8,500 ton diesel-electric Project 23550 military icebreaking patrol vessels (corvettes) will be armed combatant vessels capable of breaking ice with a thickness up to 1.7 meters (5.6 feet). The keel for the lead ship, Ivan Papanin, was laid down at the Admiralty Shipyard in St. Petersburg on 19 April 2017. Construction time is expected to be about 36 month, with Ivan Papanin being commissioned in 2020. The second ship in this class should enter service about one year later. Both corvettes are expected to be armed with a mid-size naval gun (76 mm to 100 mm have been reported), containerized cruise missiles, and an anti-submarine capable helicopter (i.e., Kamov Ka-27 type). The U.S. has no counterpart to this class of Arctic vessel.

Project 23550 icebreaking patrol vessel. Source: naval-technology.com

You’ll find more information on Russia’s Project 23550-class icebreaking patrol vessels here:

http://www.naval-technology.com/projects/ivan-papanin-project-23550-class-arctic-patrol-vessels/

In conclusion:

It appears to me that Russia and the U.S. have very different visions for how they will conduct and support future civilian and military operations that require surface access in the Arctic region. The Russians currently have a strong polar icebreaking capability to support its plans for Arctic development and operation, and that capability is being modernized with a new fleet of the world’s largest nuclear-powered icebreakers. In addition, two smaller icebreaking vessel classes, including an icebreaking combatant vessel, soon will be deployed to support Russia’s military in the Arctic and Far East.

In comparison, the U.S. polar icebreaking capability continues to hang by a thread (i.e., the Polar Star) and our nation has to decide if it is even going to show up for polar icebreaking duty in the Arctic in the near future. The U.S. also is a no-show in the area of dedicated military icebreakers, including Arctic-capable armed combatant surface vessels.

Where do you think this Arctic imbalance is headed?

 

Near-Earth Object (NEO) Sky Surveys and Data Analysis are Refining our Understanding of the Risk of NEO Collisions with Earth

It seems that every week or two there is a news article about another small asteroid that soon will pass relatively close to the Earth. Most were detected while they were still approaching Earth. Some were first detected very shortly before or after their closest approach to Earth. That must have made the U.S. Planetary Defense Officer a bit nervous, but then, what could he do about it? (See my 21 January 2016 post, “Relax, the Planetary Defense Officer has the watch”).

While we currently can’t do anything to defend against NEOs, extensive worldwide programs are in place to identify and track NEOs and predict which NEOs may present a future hazard to the Earth. Here’s a brief overview of the following programs.

  • NASA Wide-field Infrared Survey Explorer (WISE)
  • International Astronomical Union’s (IAU’s) Minor Planet Center (MPC)
  • NASA’s Center for Near Earth Object Studies (CNEOS)
  • National Optical Astronomy Observatory (NOAO) NEO sky survey
  • University of Arizona Lunar and Planetary Laboratory

NASA’s Wide-field Infrared Survey Explorer (WISE)

WISE was an Earth orbiting infrared-wavelength astronomical space telescope with a 40 cm (16 in) diameter primary mirror. WISE operated from December 2009 to February 2011 and performed an “all-sky” astronomical imaging survey in the 3.4, 4.6, 12.0 and 22.0 μm wavelength bands. NASA’s home page for the WISE / NEOWISE mission is at the following link:

https://www.nasa.gov/mission_pages/neowise/mission/index.html

NEOWISE is the continuing NASA project to mine the WISE data set. An important data mining tool is the WISE Moving Object Processing System (WMOPS), which has been optimized to enable extraction of moving objects at lower signal-to-noise levels. A comet detection is shown in the following multiple images that have been combined to show the comet in four different positions relative to the fixed background stars.

Comet C/2013 A1 Siding Spring. Source: NASA/JPL-Caltech

To date, the NEOWISE data mining effort has resulted in the following:

  • Detection of ~158,000 asteroids at thermal infrared wavelengths, including ~700 near-Earth objects (NEOs) and ~34,000 new asteroids, 135 of which are NEOs.
  • Detection of more than 155 comets, including 21 new discoveries.
  • Determination of preliminary physical properties such as diameter and visible albedo for nearly all of these objects.
  • Estimation of the numbers, sizes, and orbital elements of NEOs, including potentially hazardous asteroids
  • Results have been published, enabling a range of other studies of the origins and evolution of the small bodies in our solar system.

The output from NEOWISE is delivered to NASA’s Planetary Data System (PDS), which NASA describes as follows:

“The PDS archives and distributes scientific data from NASA planetary missions, astronomical observations, and laboratory measurements. The PDS is sponsored by NASA’s Science Mission Directorate. Its purpose is to ensure the long-term usability of NASA data and to stimulate advanced research. All PDS data are publicly available and may be exported outside of United States under ‘Technology and Software Publicly Available’ (TSPA) classification.”

The link to the NASA Planetary Data System is here:

https://pds.nasa.gov

International Astronomical Union’s (IAU’s) Minor Planet Center (MPC)

The MPC describes itself as the “single worldwide location for receipt and distribution of positional measurements of minor planets, comets and other irregular natural satellites of the major planets. The MPC is responsible for the identification, designation and orbit computation for all of these objects.”

The MPC home page is here:

http://www.minorplanetcenter.net/iau/mpc.html

On this website, MPC lists the following 2017 summary statistics:

Source: MPC

The MPC website offers several short videos that explain the NEO hazard and the challenges of detecting these small objects and determining their orbital parameters with high precision. Key points made in the MPC videos include:

  • The Earth’s cross-section represents only 1/10,000th of the area of the near-Earth region. Earth is a relatively small target area for a NEO.
  • To determine if a NEO is a potential hazard, its orbital parameters must be established with a precision of greater than 1/100th of 1%.
  • There is a “zone of discoverability” (green area in the following diagram) that varies primarily by the size of the object and the aspect of its lighted side to observers on Earth. If an object is outside this rather small zone, then current sky survey instruments cannot detect the object. An example is the 15 February 2013 atmospheric blast that occurred near Chelyabinsk, Russia. This event was caused by a previously undetected NEO that approached Earth at a high relative velocity from the direction of the Sun and vaporized in the Earth’s atmosphere.

            Zone of discoverability (green area). Source: screenshot from MPC video “Asteroid Hazards, Part 2: The Challenge of Detection”

 NASA’s Center for Near Earth Object Studies (CNEOS)

CNEOS is NASA’s center for computing asteroid and comet orbits with high precision and estimating the probability of a future Earth impact. CNEOS is operated by the California Institute of Technology (Caltech) Jet Propulsion Laboratory (JPL) and supports NASA’s Planetary Defense Coordination Office.

The CNEOS home page is here:

http://cneos.jpl.nasa.gov/about/cneos.html

CNEOS is the home of JPL’s Sentry and Scout programs:

  • The Sentryimpact monitoring system performs long-term analyses of possible future orbits of hazardous asteroids, searching for impact possibilities over the next century.
  • TheScout system monitors the IAU’s MPC database for new potential asteroid discoveries and computes the possible range of future motions even before these objects have been confirmed as discoveries.

The average distance between the Earth and the moon is about 238,855 miles (384,400 km), which equals 1 LD. On the CNEOS website, you can view data on NEO close approaches to Earth at the following link:

https://cneos.jpl.nasa.gov/ca/neo_ca_intro.html

By adjusting the table settings and sorting by a specific column heading, you can create customized views of the close approach data. Just looking at data from the past year for NEOs that passed Earth within 1 LD yielded the following results:

  • 48 NEOs passed within 1 LD of Earth.
  • For these NEOs, object diameters were in the range from 1.8 to 83 meters (5.9 to 272 feet). The NEO that caused the 2013 Chelyabinsk blast was estimated to have a diameter of 10 to 20 meters (32.8 to 65.6 feet).
  • Their relative velocities were in the range from 4.02 to 23.97 km/s (8,992 to 53,620 mph). The NEO that caused the 2013 Chelyabinsk blast was estimated to have a relative velocity of 19.16 km/s (45,860 mph).
  • In the past year, the closest approach was by object 2017 GM, which had a “CA Distance Minimum” (3-signa estimate, measured from Earth center to NEO center) of 0.04 LD, or 15,376 km (9,554 miles). After subtracting Earth’s radius of 6,371 km (3,959 miles), object 2017 GM cleared the Earth’s surface by 9,005 km (5,595 miles).

Looking into the future, the CNEOS close approach data shows two objects that currently have values of “CA Distance Minimum” that are less than the radius of the Earth, indicating that impact is possible:

  • Object 2012 HG2: close approach date on 13 February 2047; modest size of 11 – 24 meters (36 – 79 feet); low relative velocity of 4.36 km/sec (9,753 mph)
  • Object 2010 RF12: close approach date of 6 September 2095; modest size of 6.4 – 14 meters (21 to 46 feet); modest relative velocity of 7.65 km/sec (17,112 mph)

So it looks like we have less than 30 years to refine the orbital data on object 2012 HG2, determine if it will impact Earth, and, if so, determine where the impact will occur and what mitigating actions can be taken. Hopefully, the U.S. Planetary Defense Officer is on top of this matter.

National Optical Astronomy Observatory (NOAO) NEO sky survey

On 30 August 2017, NOAO issued a press release summarizing the results of a survey of NEOs conducted using the Dark Energy Camera (DECam) on the 4 meter (157.5 inch) Blanco telescope at the Cerro Tololo Inter-American Observatory in northern Chile.

“Lori Allen, Director of the Kitt Peak National Observatory and the lead investigator on the study, explained, ‘There are around 3.5 million NEOs larger than 10 meters, a population ten times smaller than inferred in previous studies. About 90% of these NEOs are in the Chelyabinsk size range of 10-20 meters.’”

“David Trilling, the first author of the study,…explained…..‘If house-sized NEOs are responsible for Chelyabinsk-like events, our results seem to say that the average impact probability of a house-sized NEO is actually ten times greater than the average impact probability of a large NEO.’”

You can read the NOAO press release here:

https://www.noao.edu/news/2017/pr1704.php

You can read the draft paper, “The size distribution of Near Earth Objects larger than 10 meters,” (to be published in Astronomical Journal) here.

https://arxiv.org/pdf/1707.04066.pdf

University of Arizona Lunar and Planetary Laboratory

In October 2017, astronomer Vishnu Reddy presented data on an intriguing NEO known as 2016 HO3, that is a “quasi-satellite” of Earth. The announcement is here:

https://lbtonews.blogspot.com/2017/10/earths-new-traveling-buddy-is.html

As a “quasi-satellite,” 2016 HO3 is not gravitationally bound to Earth, but its solar orbit keeps 2016 HO3 in relatively close proximity to Earth, but in a slightly different orbital plane. As both bodies orbit the Sun, the motion of 2016 HO3 relative to the Earth gives the appearance that 2016 HO3 is in a distant halo orbit around Earth. The approximate geometry of this three body system is shown in the following diagram, with 2016 HO3’s solar orbit represented in red and the halo orbit as seen from Earth represented in yellow.

Source: www.EarthSky.org

You’ll find a video showing the dynamics of 2016 HO3’s halo orbit on the EarthSky website at the following link:

http://earthsky.org/space/near-earth-quasi-satellite-2016-ho3-confirmation?mc_cid=4d2056208e&mc_eid=19a1fde155

Observations of 2016 HO3 were made from the Large Binocular Telescope Observatory (LBTO), which is located on Mt. Graham in Arizona. You’ll find details on LBTO at the following link:

http://www.lbto.org/overview.html

Key parameters for 2016 HO3 are: diameter: 100 meters (330 feet); distance from Earth: 38 to 100 LD; composition appears to be the same material as other asteroid NEOs. With its stable halo orbit, there is no risk that 2016 HO3 will collide with Earth.

For additional reading on NEO discovery:

Myhrvold, “Comparing NEO Search Telescopes,” Astronomical Society of the Pacific, April 2016

Abstract:

“I use simple physical principles to estimate basic performance metrics for the ground-based Large Synoptic Survey Telescope and three space-based instruments— Sentinel, NEOCam, and a Cubesat constellation.”

http://iopscience.iop.org/article/10.1088/1538-3873/128/962/045004/pdf

S.R. Chesley & P. Vereš, “Projected Near-Earth Object Discovery Performance of the Large Synoptic Survey Telescope,” JPL Publication 16-11, CNEOS, April 2017

Abstract:

“LSST is designed for rapid, wide-field, faint surveying of the night sky ….The baseline LSST survey approach is designed to make two visits to a given field in a given night, leading to two possible NEO detections per night. These nightly pairs must be linked across nights to derive orbits of moving objects…… Our simulations revealed that in 10 years LSST would catalog 60% of NEOs with absolute magnitude H < 22, which is a proxy for 140 m and larger objects.”

https://cneos.jpl.nasa.gov/doc/JPL_Pub_16-11_LSST_NEO.pdf

 

60th Anniversary of Sputnik 1, the World’s First Man-made Earth-orbiting Satellite

4 October 1957 was a major milestone in aerospace history, marking the first launch of an artificial satellite into Earth orbit.  Since 1955, a relatively low-key “space race” between the U.S. and the Soviet Union had been underway, with the U.S. openly developing the small Vanguard booster rocket and satellite and planning to launch the first satellite into orbit during the International Geophysical Year (1 July 1957 to 31 December 1958).  Secrecy surrounding the Soviet Union’s space program made the successful launch of Sputnik 1 a significant political coup, which served to greatly energized the lagging U.S. space program and prompted calls for more technical education in the U.S.

Source:  The New York Tines

The small spherical Sputnik 1 satellite had a diameter of 23 inches (58 cm) and a weight of 184 pounds (83.6 kg).  Functionally, Sputnik 1 was very simple, consisting of a battery power supply, a radio transmitter, a thermal control system and a remote control switch housed within the nitrogen-pressurized sphere. You’ll find a description of how Sputnik 1 worked at the following link:

http://www.popularmechanics.com/space/satellites/news/a28496/how-sputnik-worked/

The satellite transmitted a continuous “beep-beep-beep…” until 28 October 1957, when it went silent.

Source:  Smithsonian Air and Space Museum

Sputnik 1 interior arrangement. Source: Space.com

Sputnik was launched by an R-7 liquid-fueled booster rocket, which was a version of the Soviet Union’s first intercontinental ballistic missile (ICBM).  The R-7 booster rocket was developed by the design bureau headed by Sergei Pavlovitch Korolev (1906-1966). That booster evolved into the launch vehicle for future Soviet Vostok and Voskhod projects, and a version continues in use today as the Russian launch vehicle taking astronauts and supplies to the International Space Station (ISS).

R-7 booster.  Source: Space.com

Sputnik 1’s low Earth orbit decayed over the next three months and the satellite reentered the Earth’s atmosphere and was destroyed on 4 January 1959, after about 1,400 orbits.  Sputnik 1 had a lasting effect on the space race between the U.S. and the Soviet Union.

 

 

Remote Sensing Shows the Extent of Flooding from Hurricane Harvey and Other Large Flooding Events

Dartmouth Flood Observatory, at the University of Colorado, Boulder, CO, integrates international satellite data to develop a worldwide view of surface water issues, and can provide regional maps that show the extent of flooding in areas of interest. Data from many satellite sources are used, including NASA’s MODIS (Moderate Resolution Imaging Spectrometer) and Landsat, European Space Agency’s (ESA) Sentinel 1, ASI (Agenzia Spaziale Italiana) Cosmos-SkyMed, and Canadian Space Agency’s Radarsat 2.

The Dartmouth Flood Observatory homepage is here:

http://floodobservatory.colorado.edu

The world view of large flooding events as of 26 August 2017 is shown in the graphic.

Source: Dartmouth Flood Observatory

The following 31 August 2017 maps show the areas in Texas and Louisiana that were flooded by Hurricane Harvey also known as DFO flood event 4510). Red represents flooded areas, blue represents normal water extent, and dark grey represents urban areas.

Area mapSource: Dartmouth Flood Observatory

Here’s the link to these detailed flooding maps for Hurricane Harvey:

http://floodobservatory.colorado.edu/Events/2017USA4510/2017USA4510.html

This webpage also provides links to other information sources related to Hurricane Harvey.

The Dartmouth Flood Observatory maintains an archive of large flood events from 1985 to present. This archive is accessible online at the following link:

http://floodobservatory.colorado.edu/Archives/index.html

Dartmouth Flood Observatory is a member of the Global Flood Partnership (GFP), which describes itself as, “a cooperation framework between scientific organizations and flood disaster managers worldwide to develop flood observational and modeling infrastructure, leveraging on existing initiatives for better predicting and managing flood disaster impacts and flood risk globally.” For more information on the Global Flood Partnership, visit their homepage and portal at the following links:

https://gfp.jrc.ec.europa.eu/about-us

http://portal.gdacs.org/Global-Flood-Partnership

The Importance of Baseload Generation and Real-Time Control to Grid Stability and Reliability

On 23 August 2017, the Department of Energy (DOE) issued a report entitled, “Staff Report to the Secretary on Energy Markets and Reliability.” In his cover letter, Energy Secretary Rick Perry notes:

“It is apparent that in today’s competitive markets certain regulations and subsidies are having a large impact on the functioning of markets, and thereby challenging our power generation mix. It is important for policy makers to consider their intended and unintended effects.”

Among the consequences of the national push to implement new generation capacity from variable renewable energy (VRE) resources (i.e., wind & solar) are: (1) increasing grid perturbations due to the variability of the output from VRE generators, and (2) early retirement of many baseload generating plants because of several factors, including the desire of many states to meet their energy demand with a generating portfolio containing a greater percentage of VRE generators. Grid perturbations can challenge the reliability of the U.S. bulk power systems that comprise our national electrical grid. The reduction of baseload capacity reduces the resilience of the bulk power system and its ability dampen these perturbations.

The DOE staff report contains the following typical daily load curve. Baseload plants include nuclear and coal that operate at high capacity factor and generally do not maneuver in response to a change in demand. The intermediate load is supplied by a mix of generators, including VRE generators, which typically operate at relatively low capacity factors. The peak load generators typically are natural gas power plants that can maneuver or be cycled (i.e., on / off) as needed to meet short-term load demand. The operating reserve is delivered by a combination of power plants that can be reliably dispatched if needed.

The trends in new generation additions and old generation retirements is summarized in the following graphic from the DOE staff report.

Here you can see that recent additions (since 2006) have focused on VRE generators (wind and solar) plus some new natural gas generators. In that same period, retirements have focused on oil, coal and nuclear generators, which likely were baseload generators.

The DOE staff report noted that continued closure of baseload plants puts areas of the country at greater risk of power outages. It offered a list of policy recommendations to reverse the trend, including providing power pricing advantages for baseload plants to continue operating, and speeding up and reducing costs for permitting for baseload power and transmission projects.

Regarding energy storage, the DOE staff report states the following in Section 4.1.3:

“Energy storage will be critical in the future if higher levels of VRE are deployed on the grid and require additional balancing of energy supply and demand in real time.”

“DOE has been investing in energy storage technology development for two decades, and major private investment is now active in commercializing and the beginnings of early deployment of grid-level storage, including within microgrids.”

Options for energy storage are identified in the DOE staff report.

You can download the DOE staff report to the Secretary and Secretary Perry’s cover letter here:

https://energy.gov/downloads/download-staff-report-secretary-electricity-markets-and-reliability

Lyncean members should recall our 2 August 2017 meeting and the presentation by Patrick Lee entitled, “A fast, flexible & coordinated control technology for the electric grid of the future.” This presentation described work by Sempra Energy and its subsidiary company PXiSE Energy Solutions to address the challenges to grid stability caused by VRE generators.   An effective solution has been demonstrated by adding energy storage and managing the combined output of the VER generators and the energy storage devices in real-time to match supply and demand and help stabilize the grid. This integrated solution, with energy storage plus real-time automated controls, appears to be broadly applicable to VRE generators and offers the promise, especially in Hawaii and California, for resilient and reliable electrical grids even with a high percentage of VRE generators in the state’s generation portfolio.

You can download Patrick Lee’s 2 August 2017 presentation to the Lyncean Group of San Diego at the following link:

http://www.lynceans.org/talk-113-8217/

 

 

 

 

Return of the Stellarator

Background

Dr. Lyman Spitzer invented the stellarator in 1951 and built several versions of this magnetic plasma confinement machine at Princeton University during the 1950s and 1960s, establishing the world famous Princeton Plasma Physics Laboratory (PPPL) in the process. Dr. Spitzer’s earliest Stellarators were figure-eight devices as shown in the following photo.

Example of an early stellarator at the 1958 Atoms for Peace Conference, Geneva

In these first-generation stellarators, field coils wrapped around the figure-eight vacuum vessel provided the basic plasma confinement field. The physical twist in the stellarator’s structure twisted the internal magnetic confinement field and cancelled the effects of plasma ion drift during each full circuit around the device. You can download Dr. Spitzer’s historic 1958 IAEA conference paper, “The Stellarator Concept,” at the following link:

http://www-naweb.iaea.org/napc/physics/2ndgenconf/data/Proceedings%201958/papers%20Vol32/Paper23_Vol32.pdf

The next generation of stellarators adopted a simpler torus shape and created the twist in the magnetic confinement field with helical field coils outside the vacuum vessel.

While stellarators achieved many important milestones in magnetic confinement, by the late 1960s, the attention of the fusion community was shifting toward a different type of magnetic confinement machine: the tokamak. Since then, this basic design concept has been employed in many of the world’s major fusion devices, including the Alcator-C Mod (MIT, USA), Doublet III-D (DIII-D at General Atomics, USA), Tokamak Fusion Test Reactor (TFTR at PPPL, USA), Joint European Torus (JET, UK), National Spherical Torus Experiment Upgrade (NSTX-U at PPPL, USA) and the International Thermonuclear Experimental Reactor (ITER, France).

Now, almost 50 years later, there is significant renewed interest in stellarators. The newest device, the Wendelstein 7-X stellarator, became operational in 2016. It may help determine if modern technology has succeeded in making the stellarator a more promising path to fusion power than the tokamak.

Comparison of Tokamaks and Stellarators

Modern tokamaks and stellarators both implement plasma confinement within a (more or less) toroidal vacuum vessel that operates at very high vacuum conditions, on the order of 10-7 torr. Both types of machines use the combined effects of two or more magnetic fields to create and control helical field lines (HFL) that enable plasma confinement and reduce particle drift in the circulating plasma.

In the following description, the simple “classical” tokamak configuration shown below will be the point of reference.

Source: Hans-Jürgen Hartfuß, Thomas Geist, “Fusion Plasma Diagnostics With mm-Waves: An Introduction”

The main features of a tokamak are summarized below.

  • The vacuum vessel in a modern tokamak typically is an azimuthally-symmetric torus of revolution (donut-shaped), typically with a vertically elongated, D-shaped cross section. Modern “spherical” tokomaks maintain the D-shaped cross section, but minimize the diameter of the hole in the center of the torus.
  • Plasma confinement within the vacuum vessel is accomplished by the combined effects of a toroidal magnetic field and an induced poloidal magnetic field. Together, these fields create the helical field lines for plasma confinement. In the following diagram, the toroidal field is represented by the blue arrow and the poloidal field is represented by the red arrow.

By Dave Burke – Own work, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1169843

  • The toroidal field (blue) is generated by a set of external toroidal field coils (TFCs) that surround the vacuum vessel.
  • The poloidal field (red) is generated by a strong induced plasma current (Iplasma), on the order of 106 amperes, flowing within the plasma inside the vacuum vessel. An external coil in the center of the tokamak serves as the primary coil of a transformer and the circulating plasma serves as the secondary coil of the transformer. To create the poloidal field, the transformer primary coil is charged at a controlled rate (i.e. to yield the desired rate of flux increase), thereby inducing a current in the plasma and heating the plasma by ohmic heating. When the primary coil reaches maximum flux, current is no longer induced in the plasma and the tokamak “pulse” is over.
  • A pair of vertical field coils (VFC), one above and one below the plane of the torus, provide the ability to radially position the plasma within the vacuum vessel.
  • Divertors inside the vacuum vessel define the maximum extent of the magnetically confined plasma, remove impurities from the edge of the plasma, and help minimize plasma-wall interactions.
  • The high current in the plasma can falter unexpectedly, resulting in a “disruption”, which is a sudden losses of plasma confinement that can unleash magnetic forces powerful enough to damage the machine.
  • A tokamak is mechanically simpler than a stellarator.
  • The physics characteristics of a tokamak typically yield better confinement capabilities than a stellarator.
  • While the “pulse” in a modern tokamak can last several tens of minutes, a pulsed mode of operation may not be suitable for a commercial fusion reactor.
  • Pulsed magnetic and thermal loads create mechanical fatigue issues that must be accommodated in the design of tokamak structures.

The simple “classical” stellarator configuration shown below will be the point of reference for the following discussion.

Source: Hans-Jürgen Hartfuß, Thomas Geist, “Fusion Plasma Diagnostics With mm-Waves: An Introduction”

The main features of a stellarator are summarized below.

  • There are many variants of devices called stellarators, with names such as Torsatron, Heliotron, Heliac, and Helias. All create the plasma confinement field with external magnet systems in various configurations and none depend on the existence of a toroidal plasma current.
  • In the classical stellarator in the above diagram, the plasma confinement field is created by a set of planar (flat) TFCs and external pairs (1, 2 or 3) of twisting helical field coils (HFC) with opposite currents in each conductor in the pair.
  • A stellarator is mechanically more complex and more difficult to manufacture than a tokamak.
  • Stellarators may use a divertor or a simpler “limiter” to define the outer extent of the plasma.
  • While a stellarator has no induced plasma current, other small currents, known as “pressure-driven” or “bootstrap” currents, exist. These small currents do not cause plasma disruptions as may occur in a tokamak, but complicate plasma confinement.
  • A stellarator is intrinsically capable of steady-state operation.
  • For a variety of reasons, a classical stellarator tends to lose energy at a higher rate than a tokamak. Advanced, modular stellarators are making progress in improving confinement performance.

You’ll find more comparative information in the July 2016 paper by Y. XU, “A general comparison between tokamak and stellarator plasmas,” which is available at the following link:

http://ac.els-cdn.com/S2468080X16300322/1-s2.0-S2468080X16300322-main.pdf?_tid=7d9ff748-c680-11e6-9909-00000aacb35d&acdnat=1482216764_912e05c8d6b4957207a2e7ae31c30f03

Modern stellarators

In the last two decades, dramatic improvements in computer power and 3-dimensional modeling capabilities have enabled researchers and designers to accurately model a stellarator’s complex magnetic fields, plasma behavior, and mechanical components (i.e., vacuum vessel, magnet systems and other structures). This has enabled implementation of a “plasma first” design process in which the initial design focus is on optimizing plasma equilibrium based on selected physics conditions. Key goals of this optimization process are to define plasma equilibrium conditions that reduce heat transport and particle loss from the plasma. As you might suspect, there are different technical bases for approaching the plasma optimization process. The stellarator’s magnet systems are designed to produce the confinement field needed for the specified, optimized plasma design.

This class of modern, optimized stellarators is characterized by complex, twisting plasma shapes and non-planar, modular toroidal coils that are individually designed, built and assembled. The net result is a stellarator with significantly better confinement performance that earlier stellarator designs. In this post, we’ll look in more detail at the following three advanced stellarators:

  • Wendelstein 7-AS [Max Planck Institute for Plasma Physics (IPP), Garching, Germany]
  • Helically Symmetric eXperiment (HSX, University of Wisconsin – Madison, USA)
  • Wendelstein 7-X [Max Planck Institute for Plasma Physics (IPP), Griefswald, Germany]

 Wendelstein 7-AS Stellarator (1988 – 2002)

The Wendelstein 7-AS was the first modular, advanced stellarator and was the first stellarator equipped with a divertor. It was used to test and validate basic elements of stellarator optimization.  Basic physical parameters of 7-AS are:

  • Major radius 2 m
  • Minor radius 0.2 m
  • Magnetic field 2.5 – 3 T

The physical layout and scale of the 7-AS machine is shown in the first diagram, below, with more details on the magnet system in the following diagram.

Above & below: Wendelstein 7-AS. Source: Max Planck IPP, I. Weber

The 7-AS operated from 1988 to 2002.   The IPP reported the following results:

  • Demonstrated that the innovative modular magnet coil system can be manufactured to exacting specifications.
  • Demonstrated improved plasma equilibrium and transport behavior because of the improved magnetic field structure.
  • Confirmed the effectiveness of the optimization criteria.
  • Demonstrated the effectiveness of a divertor on a stellarator (a common feature in tokamaks).

You’ll find more details on the 7-AS on the IPP website at the following link:

http://www.ipp.mpg.de/2665443/w7as?page=1

Its successor is the Wendelstein 7-X.

Helically Symmetric eXperiment (HSX)

HSX is a small modular coil advanced stellarator that began operation in 1999 at the Electrical and Computer Engineering Department at the University of Wisconsin-Madison. HSX basic design parameters are:

  • Major radius 1.2 m
  • Minor radius 0.15 m
  • Magnetic field 1T

The physical arrangement of HSX is shown in the following diagram.

HSX physical configuration. Source: University of Wisconsin – Madison

The HSX was the first stellarator to be optimized to deliver a “quasi-symmetric” magnetic field. While the magnetic field strength is usually a two-dimensional function on the magnetic surfaces traced out by the field lines, quasi-symmetry is achieved by making it one-dimensional in so-called “magnetic coordinates” (Boozer coordinates).

Author Masayuki Yokoyama’s paper, “Quasi-symmetry Concepts in Helical Systems,” provides a description of quasi-symmetry.

“A key point of quasi-symmetry is that the drift trajectories of charged particles depend on the absolute value of the magnetic field (B) expressed in terms of magnetic field coordinates (Boozer coordinates). The plasma can be optimized in terms of the Boozer coordinates instead of the vector components of the field.”

You can read Yokoyama’s complete paper at the following link:

https://www.jstage.jst.go.jp/article/jspf/78/3/78_3_205/_pdf

The HSX main magnetic field is generated by a set of 48 non-planar, modular coils, arranged in four field periods, yielding the twisting flux shape shown below.


HSX plasma configuration. Source: University of Wisconsin – Madison

The HSX team reported that “this is the first demonstration that quasi-symmetry works, and you can actually measure the reduction in transport that you get.”

The home page for this project is at the following link:

http://www.hsx.wisc.edu

You can download a description of the HSX here:

http://www.hsx.wisc.edu/wp-uploads/2016/04/A-helically-symmetric-stellarator-HSX_Almagri_Anderson-DT_Anderson-FSB_Probert_Shohet_Talmadge_1999.pdf

 Wendelstein 7-X Stellarator

The Wendelstein 7-X is a Helias (helical advanced stellarator) and is the first large-scale optimized stellarator; significantly larger than Wendelstein 7-S and HSX. The complete 7-X machine weighs about 750 tons, with about 425 tons operating under cryogenic conditions. The superconducting magnet system is designed for steady-state, high-power operation; nominally 30 minutes of plasma operation at 10 MW power. 7-X basic design parameters are:

  • Major radius 5.5m
  • Minor radius 0.52m
  • Magnetic field 2.5 T (up to 3T)

The IPP home page for this project is here:

http://www.ipp.mpg.de/w7x

The 7-X is drift optimized for improved thermal and fast ion confinement by: (a) implementing quasi-symmetry to reduce transport losses, (b) minimizing plasma currents (Pfirsch-Schluter & bootstrap currents) to improve equilibrium, and (c) designing a large magnetic well in the plasma cross-section to avoid plasma pressure instabilities.

The primary purpose of the Wendelstein 7-X is to investigate the new stellarator’s suitability for extrapolation to a fusion power plant design. The IPP website provides the following clarification:

“It is expected that plasma equilibrium and confinement will be of a quality comparable to that of a tokamak of the same size. But it will avoid the disadvantages of a large current flowing in a tokamak plasma: With plasma discharges lasting up to 30 minutes, Wendelstein 7-X is to demonstrate the essential stellarator property, viz. continuous operation.”

The main assembly of Wendelstein 7-X was completed in 2014. An IPP presentation on the manufacturing and assembly of 7-X is at the following link:

https://www.iter.org/doc/www/content/com/Lists/Stories/Attachments/680/ITER_W7X.pdf

You’ll also find a good video, “Wendelstein 7-X — from concept to reality,” which provides an overview of the design and construction of the 7-X stellarator and the associated research facility, at the following link:

https://www.youtube.com/watch?v=lyqt6u5_sHA

After engineering tests, the first plasma was produced at 7-X on 10 December 2015. A November 2016 article in Nature summarized on the results of initial operation of 7-X.  The article, entitled, “Confirmation of the topology of the Wendelstein 7-X magnetic field to better than 1:100,000,” confirmed that the 7-X is producing the intended confinement field. This article includes the following 3-D rendering and description of the complex magnetic coil sets that establish the twisting plasma confinement fields in the 7-X.

“Some representative nested magnetic surfaces are shown in different colors in this computer-aided design (CAD) rendering, together with a magnetic field line that lies on the green surface. The coil sets that create the magnetic surfaces are also shown, planar coils in brown, non-planar coils in grey. Some coils are left out of the rendering, allowing for a view of the nested surfaces (left) and a Poincaré section of the shown surfaces (right). Four out of the five external trim coils are shown in yellow. The fifth coil, which is not shown, would appear at the front of the rendering.”

You can read the complete article at the following link:

http://www.nature.com/articles/ncomms13493

A more detailed mechanical view of the 7-X, with a scale (gold) human figure is shown in the following diagram:

Source: IPP presentation, “Stellarators difficult to build? The construction of Wendelstein 7-X”

The large scale of the 7-X vacuum vessel is even more apparent in the following photo.

Source: adapted from IPP by C. Bickel and A. Cuadra/Science

Current status is outlined in a February 2017 presentation by the 7-X team to the Fusion Energy Science Advisory Committee (FESAC), entitled “Recent results and near-term plans for Wendelstein 7-X,” which is available at the following link:

http://www.firefusionpower.org/FESAC_W7-X_Pedersen_02.2017.pdf

Conclusion

So the jury is still out on the ability of advanced stellarators to take the lead over tokamaks in the long, hard journey toward the goal of delivering usable power from a fusion machine. Hopefully, the advanced stellarators will move the fusion community closer to that goal.  No doubt, we still have a very long way to go before fusion power becomes a reality.

For more background information on stellarators:

A summary of Dr. Spitzer’s pioneering work at PPPL is documented in a presentation entitled, “Spitzer’s Pioneering Fusion Work and the Search for Improved Confinement,” which you can download at the following link:

http://w3.pppl.gov/~hammett/refs/2013/Spitzer_100th_Hammett_2013.pdf

There is a good briefing on the basics of stellarator design and operation in the following two documents:

Dudson, B., “Stellarators,” University of York, UK, 6 February 2014 at the following link:

http://www-users.york.ac.uk/~bd512/teaching/media/mcf_lecture_06.pdf

Beidler, C.D., et al., “Stellarator Fusion Reactors – an Overview”, Max-Planck Institute for Plasma Physics, 2001, at the following link:

http://fire.pppl.gov/itc12_wobig_paper.pdf