A fast new method for measuring hard-to-diagnose 3-D plasmas in fusion facilities

Scientists at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) and the National Institute for Fusion Science (NIFS) in Japan have developed a rapid method for meeting a key challenge for fusion science. The challenge has been to…

Scientists at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) and the National Institute for Fusion Science (NIFS) in Japan have developed a rapid method for meeting a key challenge for fusion science. The challenge has been to simulate the diagnostic measurement of plasmas produced by twisting, or 3D, magnetic fields in fusion facilities. While such fields characterize facilities called stellarators, otherwise symmetric, or 2D, facilities such as tokamaks also can benefit from 3D fields.

Researchers led by PPPL physicist Sam Lazerson have now created a computer code that simulates the required diagnostics, and have validated the code on the Large Helical Device stellarator in Japan. Called “Diagno v2.0,” the new program utilizes information from previous codes that simulate 3D plasmas without the diagnostic measurements. The addition of this new capability could, with further refinement, enable physicists to predict the outcome of 3D plasma experiments with a high degree of accuracy.
Lazerson and co-authors Satoru Sakakibara and Yasuhiro Suzuki of NIFS have published their paper online in the February issue of Plasma Physics and Controlled Fusion. The journal also is using a Lazerson graphic of a simulated plasma on the cover of its print edition.
The researchers employed a mathematical technique called “virtual casing” to develop the new code for 3D fusion plasmas that are in equilibrium. Such plasmas are held steady by the balance between the inward pressure of the magnetic fields that confine them and the outward pressure exerted by the plasma. Virtual casing enabled the researchers to efficiently calculate magnetic diagnostic signals given a simulated plasma. This was achieved by recognizing that the magnetic field at the edge of the simulated plasma was all that was necessary to calculate the magnetic diagnostic signals.
The new code can be used with both the Variational Moments Equilibrium Code (VMEC) and the Princeton Iterative Equilibrium Solver (PIES). VMEC simulates a plasma that contains a set of smoothly nested magnetic field lines. In PIES simulations, the fields inside the plasma can break up into islands and be chaotically distributed. The new code’s versatility thus enables it to simulate diagnostic measurements for both types of simulated plasmas.
Researchers are currently refining their code to reconstruct conditions that experimenters seek to create in fusion plasmas. Reconstructing these conditions calls for creating multiple iterations of the code through massive parallel processing, until the simulated measurements of the plasma precisely match the conditions measured in the experiment. Experimenters armed with this knowledge could then predict how the conditions they create in actual plasmas could affect the diagnostic outcome.

More information: dx.doi.org/10.1088/0741-3335/55/2/025014
Provided by

Princeton Plasma Physics Laboratory

view popular
send feedback to editors

5 /5 (2 votes)

1
2
3
4
5

Move the slider to adjust rank threshold, so that you can hide some of the comments.

Display comments:
newest first

Rank

1
2
3
4
5

5 /5 (2 votes)

more news

Related Stories

Nov 10, 2011
0
Video simulation puts a new twist on fusion plasma research

Nov 10, 2011
0
A new spin on understanding plasma confinement

Nov 10, 2011
0
With lithium, more is definitely better

Nov 10, 2011
0
Tokamak experiments come clean about impurity transport

Relevant PhysicsForums posts

Question about brightness temperatur​e
6 hours ago
It is possible to convert brightness temperature of Earth surface (K) to the actual temperature?
Is there any formulae for such conversion?
Thanks in advance!

Transverse waves(a string)
20 hours ago
Hi, Can anybody explain how by giving an vertical impulse to a string you can cause a transverse wave. What is confusing me is that you just give the string an impulse upwards, where does the energy…

Friciton drives a car forward right?
20 hours ago
Car wheels spin backwards and the friction force acts forward so the resultant force allows the car to move forward right?

because I saw someone say something about… cars appear to be spinning…

Citadel Physics Wave Pendulum
Mar 12, 2013
This is neat how the waves go in order then out then back in and out and back in!

1M8ciWSgc_k

Sign conventions
Mar 12, 2013
Does anyone know if the sign convenmtion from the metric tensor is linked to the sign convention in the Dirac equation. i.e is it possible to have a dt^2 – dX^2-dY^2-dZ^2 metric,

with a (-,+,+,+)…

Gravitational Force Units Question
Mar 12, 2013
I just have a question concerning a previous thread about gravitation.

The formula is from post 19 at http://www.physicsforums.com/showthread.php?t=635188&page=2

v= dr/dt

a = dv/dt

More from Physics Forums – General Physics

More news stories

Physicists use mechanical micro-drum used as quantum memory

JILA researchers demonstrated thatinformation encoded as a specific point in atraveling microwave signal—the vertical and horizontal positions of a wave pattern at a certain ime—can be transferred to …

Physics / Quantum Physics

36 minutes ago |
not rated yet |
0
|

Scientists discover how photon beam can flip the spin polarization of electrons emitted from topological insulator

(Phys.org) —Plain-looking but inherently strange crystalline materials called 3D topological insulators (TIs) are all the rage in materials science. Even at room temperature, a single chunk of TI is a good …

Physics / General Physics

5 hours ago |
4 / 5 (4) |
0
|

A high-resolution endoscope as thin as a human hair

Engineers at Stanford have demonstrated a high-resolution endoscope that is as thin as a human hair with a resolution four times better than previous devices of similar design. The so-called micro-endoscope …

Physics / Optics & Photonics

5 hours ago |
5 / 5 (3) |
1
|

Scientists observe coherent propagation of single spin impurity in a chain of ultracold atoms

Many discoveries in physics came as a big surprise – for example the phenomenon, that some materials loose almost all their electrical resistance at low temperatures, or that others become superconductors …

Physics / General Physics

5 hours ago |
5 / 5 (1) |
0
|

New technique creates stronger, lightweight magnesium alloys

Researchers from North Carolina State University have developed a new technique for creating stronger, lightweight magnesium alloys that have potential structural applications in the automobile and aerospace …

Physics / Condensed Matter

5 hours ago |
5 / 5 (1) |
1
|

ALMA finds ‘monster’ starburst galaxies in the early universe

Some of the brightest galaxies in the universe – infant galaxies that churned out tens of thousands of stars each year at the dawn of the universe – evolved much sooner and in greater numbers than previously …

Space & Earth / Astronomy
36 minutes ago |
5 / 5 (1) |
1
|

Strange phallus-shaped creature provides crucial missing link: Discovery pushes fossil record back 200 million years

Christopher Cameron of the University of Montreal’s Department of Biological Sciences and his colleagues have unearthed a major scientific discovery – a strange phallus-shaped creature they found in Canada’s …

Other Sciences / Archaeology & Fossils
36 minutes ago |
5 / 5 (1) |
0
|

Protein may alter inevitability of osteoarthritis

Few things in life are inevitable – death, taxes, and, if you live long enough, osteoarthritis. No treatment will stop or significantly slow the disease, and joint replacement is the only definitive treatment. That may …

Medicine & Health / Arthritis & Rheumatism
36 minutes ago |
not rated yet |
0
|

Tapeworm DNA contains drug weak spots

For the first time, researchers have mapped the genomes of tapeworms to reveal potential drug targets on which existing drugs could act. The genomes provide a new resource that offers faster ways to develop urgently needed …

Medicine & Health / Diseases, Conditions, Syndromes
36 minutes ago |
not rated yet |
0
|

Molecule’s structure reveals new therapeutic opportunities for rare diabetes

Researchers at Sanford-Burnham Medical Research Institute have determined the complete three-dimensional structure of a protein called HNF-4α. HNF-4α controls gene expression in the liver and pancreas, …

Medicine & Health / Medical research
36 minutes ago |
not rated yet |
0
|

Team finds mechanism that regulates production of energy-burning brown fat

Joslin scientists have discovered a mechanism that regulates the production of brown fat, a type of fat which plays an important role in heat production and energy metabolism. The findings, which appear in the upcoming issue …

Medicine & Health / Medical research
36 minutes ago |
not rated yet |
0
|