Slab-like micro-tearing mode(SLiM) model

This software provides a rapid assessment of the slab-like microtearing mode using a global linear dispersion model, which takes minutes to calculate the growth rate and frequency of a given mode.  


GitHub link

To install: pip install SLiM-phys

This talk will present a global reduced model for microtearing modes (MTM) in the H-mode pedestal, which reproduces distinctive features of experimentally observed magnetic fluctuations, such as chirping and discrete frequency bands with definite mode numbers. Our model, importantly, includes the global variation of the q profile and diamagnetic frequencies.  In contrast, the local flux tube approach fails to reproduce these distinctive features.  Our model includes a recently recognized feature for MTM stability; the MTM is enabled by the alignment of a rational surface with the peak in the profile of the diamagnetic frequency. Conversely, MTMs are strongly stabilized for toroidal mode numbers for which these quantities are misaligned.  This feature explains the discrete fluctuation bands in several DIII-D and JET discharges.  Gyrokinetic global simulations of those discharges using the GENE code have also demonstrated these concepts. In this talk, we present the application of the model to many representative experimental pedestal conditions from DIII-D, by comparing the experimental spectrogram with the global reduced model and GENE simulations. The experimentally observed frequency bands overlap with the predicted frequencies of the global reduced model. The growth rate calculated by such a reduced model has a qualitative agreement with GENE global linear simulations. We also characterize the parameter regimes and scenarios in which the MTM is expected to be active. Based on recent combined experimental, theoretical, and simulation studies, it is well established that MTMs are one of the prime candidates for electron heat transport in the pedestal. A fast yet accurate reduced model for MTMs enables rapid interpretation of magnetic fluctuation data from a wide range of experimental conditions to help assess the role of MTM in the pedestal.


Work supported by US DOE grants DE-FG02-04ER54742, DE-AC02-09CH11466 and DE-FC02-04ER54698, and IFS in University of Texas at Austin. 

SLiM model Tutorial and Demonstration

mode finder GUI 

plot modified safety factor GUI

Structure of the SLiM repo GUI

SLiM object for users

Related Publication

A survey of pedestal magnetic fluctuations using gyrokinetics and a global reduced model for microtearing stability

Physics of Plasma (Editor's pick)

https://doi.org/10.1063/5.0084842 

Simulations and reduced models for Micro-tearing modes in the Tokamak pedestal

Reduced predictive models for Micro-tearing modes in the pedestal

63rd Annual Meeting of American Physical Society(APS) Divison of Plasma Physics(DPP) invited talk


https://doi.org/10.13140/RG.2.2.27713.48482

Global Theory of Microtearing Modes in the Tokamak Pedestal

# SLiM

The Slab Like Microtearing mode (SLiM) model


This software provides a rapid assessment of the slab-like microtearing mode using a global linear dispersion model, which takes minutes to calculate the growth rate and frequency of a given mode. Potentially uses 10^-5 of the computation resources for discharge study. For detail, one can check on the site(under construction): https://www.drmcurie.com/project-page/Research_Projects/SLiM


SLiM EXE can be found from this link: https://drive.google.com/drive/folders/12e1t6liY5JztwOBOLehPoV8GbfORn_j8?usp=sharing


Executable the program: 


1. Plot the modified the safety factor (q) to see if the rational surfaces are intersected with the q profile. 

 GUI:    000GUI_Plot_q_modification.py

 script: 0Plot_q_modification.py


2. Determine the stabilities of the MTM for different mode numbers 

 GUI:    000GUI_SLiM_mode_finder.py

 script: 00SLiM_mode_finder.py


3. Calculate a list of dispersion relations provided by a csv file

 script: 0MTMDispersion_list_Calc.py

 script(CPU accelerated,beta): 0MTMDispersion_list_Calc_parallel.py


This software is based on the following articles and presentations: 


1. M. Curie, J.L. Larakers, D.R. Hatch, A. Diallo, E. Hassan, O. Nelson, W. Guttenfelder, M. Halfmoon, M. Kotschenreuthe, S. M. Mahajan, R. J. Groebner (2021)"Reduced predictive models for Micro-tearing modes in the pedestal" APS DPP

https://doi.org/10.13140/RG.2.2.27713.48482


2. J.L. Larakers,  M. Curie, D. R. Hatch, R. D. Hazeltine, and S. M.Mahajan, 2021) "Global Theory of Microtearing Modes in the Tokamak Pedestal" 

https://doi.org/10.1103/PhysRevLett.126.225001



GitHub repo:

https://github.com/maxtcurie/SLiM


APS 2021 invited talk about SLiM model:

https://youtu.be/j2MYfGwlBYY


Playlist for SLiM model:

https://youtube.com/playlist?list=PLgNi5MiqkBWagsB8yRjRncsz1D4oeedQB


How to use GUI:

    mode finder GUI: https://youtu.be/R_-ldYNvmhU

    plot modified safety factor GUI: https://youtu.be/L01xl_e1bpM



CPU accellerated dispersion calculation:

    With    CPU acceleration: 297.5 sec

    Without CPU acceleration: 481.1 sec