M3D-C1 Meeting�Nate Ferraro�July 8, 2024

Agenda

• Status update & recent code changes

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• Jardin - Numerical (in)stability with toroidal rotation

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• Clauser - Impact of resistivity definition on CQ duration

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• Other issues?

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Regression Tests

commit 0d2586a783d1fa0b3b940dae1e5e5b4dfd98c8aa

Date: Sun Jul 7 01:48:58 2024 -0400

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• Stellar (m3dc1/devel): PASSED*
• Perlmutter CPU (m3dc1/devel-cpu): PASSED*
• PPPL Cluster (m3dc1/devel-centos7): PASSED*
• Flux (m3dc1/devel): PASSED*

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* On all systems: adapt regtest fails after adaptation with an HDF5 write error.

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Recent Code Changes

• Zhou: added diagnostic to output V_PD as defined by Paul, Hudson, & Helander
• V_PD = int[ dV 𝚯( 𝜅_∥ |∇_∥T|² − 𝜅_⟂|∇_⟂T|²) ] / int[dV]
• Characterizes the fractional volume where parallel transport dominates

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• Zhou: generalized nperiods to allow values different from VMEC’s nfp parameter (still need nfp to be divisible by nperiods).

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• Ferraro: added separate PUMI_UTIL_DIR directory in makefiles to point to directory containing m3dc1_meshgen (which differs from SCOREC_UTIL_DIR)

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• Ferraro: added IDL command plot_frames

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plot_frames example

• plot_frames is for outputting a series of plots at regular time intervals to make movies
• IDL> plot_frames, ‘p’, file=’C1.h5’, /mks, /iso, range=[0, 6e5], dt=10, outfile=’p_frame’
• This will write frames evenly spaced at 10 units of time apart (or as closely as possible) to “p_frame_####.eps”
• Takes the same arguments as plot_field

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• Still need to convert the frames into a movie. This can be done on the command line using ImageMagick and ffmpeg:
• mogrify -format jpg *.eps
• ffmpeg -r 2 p_frame_%04d.jpg -vcodec libx264 -crf 25 -pix_fmt yuv420p p.mp4

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Other issues

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