# H-mode_studies¶

Contacts: David Eldon

## Short Description¶

This module provides tools related to investigating H-mode transitions

## Keywords¶

H-mode, L-H transition, H-mode detector, hysteresis

## Long Description¶

H-mode studies has two sections so far.

Section 1: H-mode threshold and hysteresis studies

This section was developed to support analysis of L-H and H-L transition thresholds and hysteresis.

More scripts (in IDL) related to H-L back transition studies or L-H/H-L hysteresis can be found in iris.gat.com:/fusion/pillar-archive/u/eldond/backtrans/ . In particular, see …./backtrans/dropper/

Section 2: H-mode detector

This section was developed to serve the Consistent Automatic Kinetic Equilibria module, which is in development by David Eldon and the Kolemen group. This is currently a functional, standalone product that can be used by anyone who has Thomson data and wants to know if the plasma is in H-mode or not. It generates a metric by taking the ratio of peak pedestal inverse scale length to the average inverse scale length over part of the core plasma (but not including too close to the magnetic axis). The metric and the threshold on it were selected for empirical results, although the search for quantities to use was informed by some plasma physics understanding. Also, some consideration was given to ideas found in R. J. Groebner, et al., Nucl. Fusion 41, 1789 (2001); doi:10.1088/0029-5515/41/12/306 .

## Typical workflows¶

This module is used to:

• Study L-H and H-L transitions and hysteresis

• Decide if the plasma has an H-mode-like pedestal or not during a given time window

• DIII-D

## Relevant publications¶

• Contributed oral by Z. Yan at the 2016 IAEA Fusion Energy Conference in Kyoto: https://conferences.iaea.org/indico/event/98/session/25/contribution/664

• This module produced the figure on slide 24

• Z. Yan, P. Gohil, G. R. McKee, D. Eldon, B. Grierson, T. Rhodes, and C. C. Petty, “Turbulence and sheared flow structures behind the isotopic dependence of the L-H power threshold and H-L back transition on DIII-D”, proceedings of the 26th IAEA Fusion Energy Conference in Kyoto, Japan (2016)

• This module produced figure 10 and supported section 6

## Contributors¶

List of contributors sorted by number of lines authored:

4332 David Eldon
39 Orso Meneghini
24 Z. Anthony Xing
1 Sterling Smith
1 Nikolas Logan


None

## Users¶

List of usernames sorted by number of module imports: eldond, bykovi, knolkerm, meneghini, bergmannm, lupinl, snyder, soukhan, unterbee, weisbergd