Subscribe options

Select your newsletters:

Please enter your email address:

@

Your email address will only be used for the purpose of sending you the ITER Organization publication(s) that you have requested. ITER Organization will not transfer your email address or other personal data to any other party or use it for commercial purposes.

If you change your mind, you can easily unsubscribe by clicking the unsubscribe option at the bottom of an email you've received from ITER Organization.

For more information, see our Privacy policy.

News & Media

Latest ITER Newsline

  • Top management | Tim Luce, Head of Science & Operation

    What does a seven-year-old growing up in a small community in Arkansas know about what it means to be an 'atomic scientist'? Probably not much. Except, remember [...]

    Read more

  • Blanket shield blocks | Series production milestone in Korea

    It takes many months for a single forged block of stainless steel to be transformed into the complex shape of an ITER blanket shield block, full of gullies, cha [...]

    Read more

  • Image of the week | 5 top lid segments expected

    A little less than five years ago, in December 2015, the first segments of the ITER cryostat (out of a total of 54) were delivered to the construction site from [...]

    Read more

  • On site | As ITER begins assembly, HVAC becomes mission critical

    Not only will heating, ventilation and air conditioning (HVAC) help protect people and equipment during the assembly phase at ITER, but they will also help ensu [...]

    Read more

  • Vacuum vessel | Sector #6 is leak tight

    The first ITER vacuum vessel sector has passed a helium leak test on site with flying colours. Back in March 2020, as experts from the Korean Domestic Agency [...]

    Read more

Of Interest

See archived entries

Improving the "gold standard" of plasma behaviour

By Raphael Rosen, Princeton Plasma Physics Laboratory

Schematic of the NSTX tokamak at PPPL with a cross-section showing perturbations of the plasma profiles caused by instabilities. Without instabilities, energetic particles would follow closed trajectories and stay confined inside the plasma (blue orbit). With instabilities, trajectories can be modified and some particles may eventually be pushed out of the plasma boundary and lost (red orbit). Image by Mario Podestà. (Click to view larger version...)
Schematic of the NSTX tokamak at PPPL with a cross-section showing perturbations of the plasma profiles caused by instabilities. Without instabilities, energetic particles would follow closed trajectories and stay confined inside the plasma (blue orbit). With instabilities, trajectories can be modified and some particles may eventually be pushed out of the plasma boundary and lost (red orbit). Image by Mario Podestà.
The gold standard for modelling the behaviour of fusion plasmas may have just gotten better. Mario Podestà, a staff physicist at the US Department of Energy's Princeton Plasma Physics Laboratory (PPPL), has updated the worldwide computer program known as TRANSP to better simulate the interaction between energetic particles and instabilities—disturbances in plasma that can halt fusion reactions.

The program's updates, reported this week in Nuclear Fusion, could lead to improved capability for predicting the effects of some types of instabilities in future facilities such as ITER.

Podestà and co-authors saw a need for better modelling techniques when they noticed that while TRANSP could accurately simulate an entire plasma discharge, the code wasn't able to represent properly the interaction between energetic particles and instabilities. The reason was that TRANSP, which PPPL developed and has regularly updated, treated all fast-moving particles within the plasma the same way. Those instabilities, however, can affect different parts of the plasma in different ways through so-called "resonant processes."

The authors first figured out how to condense information from other codes that do model the interaction accurately—albeit over short time periods—so that TRANSP could incorporate that information into its simulations. Podestà then teamed up with TRANSP developer Marina Gorelenkova at PPPL to update a TRANSP module called NUBEAM to enable it to make sense of this condensed data. "Once validated, the updated module will provide a better and more accurate way to compute the transport of energetic particles," said Podestà. "Having a more accurate description of the particle interactions with instabilities can improve the fidelity of the program's simulations."

Read the full article on the PPPL website.


return to the latest published articles