April TTF, Madison/ 4th ITPA St Petersburg Clarisse Bourdelle Association EURATOM-CEA First results using kinezero because faster, and also not enough time yet to check the input file maker for GS2 Kinezero: –gyrokinetic, local, eigenvalue –ion and electron, passing and trapped –electrostatic, collionless, s- geometry, linear fast: ~150 in 1 hour on 1 CPU allows to scan extensively parameter fields C. Bourdelle, X. Garbet, G. T. Hoang et al, Nuclear Fusion 42 (2002)
April TTF, Madison/ 4th ITPA St Petersburg Clarisse Bourdelle Association EURATOM-CEA First line of attack: study impact of in ITBs, in particular ITBs with high gradP Why is particularly interesting? High lowers vertical drift, therefore lowers dominant interchange instability As is increased the confinement improves, the pressure peaks, leading to even higher : possibility for positive feedback, like for ExB stabilization Unlike ExB stabilization, no need for external momentum input: relevant for reactor scales
April TTF, Madison/ 4th ITPA St Petersburg Clarisse Bourdelle Association EURATOM-CEA JT60-U #39056 at 6.8 s and at the barrier location, gradP is high enough to be at threshold for positive feedback between and gradP gradP * 16! a high q (high ) is necessary to have below ExB but only an increase of through gradP leads to have a complete stabilization
April TTF, Madison/ 4th ITPA St Petersburg Clarisse Bourdelle Association EURATOM-CEA Growth rates very sensitive to input profiles… Here we see that a slight change of s (from 0.4 to 0.6) leads to higher than ExB As well for slightly lower or higher gradP (/2 or *2) would lead to lower So it is very important to put very carefully checked profiles in the database to allow for relevent microstability analysis
April TTF, Madison/ 4th ITPA St Petersburg Clarisse Bourdelle Association EURATOM-CEA In JET ITB, is stabilizing inside barrier A lower q would be destabilizing at barrier for ITG-TEM and ETG negligible impact of s < 0
April TTF, Madison/ 4th ITPA St Petersburg Clarisse Bourdelle Association EURATOM-CEA JET : versus for reversed (#53521) and monotonic (#46664) q-profiles qx2 #53521 at 6s#46664 at 6s
April TTF, Madison/ 4th ITPA St Petersburg Clarisse Bourdelle Association EURATOM-CEA s stable unstable stable 0 ITB triggered by s < 0 ? For example, a question that would be nice to try further to answer using the ITPA database: Is it possible to sustain ITB without ExB shear, just with stabilization? ITB triggered by high (high q) ?
April TTF, Madison/ 4th ITPA St Petersburg Clarisse Bourdelle Association EURATOM-CEA General remarks about the use of the ITPA profile database from C. Bourdelle I regret that the scenarios are not understandable from data in the database, for e.g. DIIID #87031 is only for 500ms, and #95989 for 600ms. Need to include scenarios in comments or with 1D data. Raw data for direct comparison experiments versus modelling (instead of comparing to already smoothed data) and a better understanding of the scenario Miss JT60-U data on the UK web site. Could not access the data despite going through recognised IP # UK site well documented. Should add any «private» tools, as Colin started to do. Colin developed an IDL tool to prepare GS2 input files. I am planning to add a tool to prepare KINEZERO input files and to convert the IDL get_profile in matlab. Different q-profiles obtained by TRANSP ( ITB database) and CRONOS particular JET #53521