Index of /~dlr/g-2/gm2/mytest/kicker_upgrade_evaluation/robyn/development9_linux/bmad-ecosystem/bsim/bbu
BBU program 2017 (edited by William Lou)
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The main BBU directory is bsim/bbu/ within the Git repo at <https://github.com/bmad-sim/bmad-ecosystem>
The BBU code and related files are contained in this directory, except for bsim/code/bbu_track_mod.f90.
The compiled BBU Fortran code is at production/bin/bbu by default.
The latest description of BBU program (in Latex) is under the doc directory.
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Set Up:
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1) Edit the environment variable $PYTHONPATH.
Add this line to your .bashrc file (with YOUR username):
"export PYTHONPATH=${PYTHONPATH}:<path-to-Bmad-release>/bsim/bbu/python"
where <path-to-Bmad-release> is the path to the Bmad release directory.
2) In test_run.py, properly set the BBU AND Python parameters.
The user is expected to understand what most parameters do.
MAKE SURE THE CORRECT LATTICE FILE LOCATION is specified in bbu/test_run.py
==============================================================================
Run BBU:
--------
Note: the output files will be stored in the working directory at which python3 is called.
1) DR_SCAN mode:
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Run this command under $DIST_BASE_DIR/bsim/bbu/examples :
python $DIST_BASE_DIR/bsim/bbu/test_run.py
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Obtain (Ith v.s. tr/tb) for a lattice with one cavity and varying recirculation arclength.
Can produce the plot for PRSTAB 7 (2004) Fig. 3. (with one dipole HOM assigned, and one-time recirculation)
This is the simplest mode to test if the BBU program works.
Output file: thresh_v_trotb.txt
2) THRESHOLD (CURRENT) mode:
-------------------------------------------------------------------------
Command: python $DIST_BASE_DIR/bsim/bbu/test_run.py N fn output_dir
-------------------------------------------------------------------------
For a FIXED lattice with many cavities assigned with (random) HOMs,
compute the threshold current for N times.
It is recommended to set N = 1 for parallel computation.
( fn is the file number, and set to the job number ($JOB_ID) during grid submission )
Output file: bbu_threshold_fn.txt and rand_assign_homs_fn.txt
rand_assign_homs_fn.txt will NOT be produced if random_HOM is set false
3) PHASE_SCAN mode:
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Command: python $DIST_BASE_DIR/bsim/bbu/test_run.py PHASE
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Obtain (Ith v.s. tr/tb) for a lattice with varying horizontal PHASE ADVANCE.
Phase is changed via a Taylor element in the lattice, named talylorW.
The correct Twiss parameters must be extracted from the lattice and set in phase_scan.py.
Output file: thresh_v_phase_PHASE.txt (produced at where it's called)
4) PHASE_SCAN_XY mode:
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Command: python $DIST_BASE_DIR/bsim/bbu/test_run.py PHASE_X PHASE_Y
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Obtain (Ith versus tr/tb) for a lattice with two free phases (with coupled or decoupled optics)
Phase advances are changed via a Taylor element in the lattice, named talylorW.
The correct Twiss parameters must be extracted from the lattice and set in phase_scan.py.
Output file: thresh_v_phase_PHASE.txt (produced at where it's called)
==============================================================================
Important Files:
----------------
-> BBU Fortran codes (Core Computation):
1) .../bsim/bbu/bbu_program.f90 --- Main bmad / tracking code
2) .../bsim/code/bbu_track_mod.f90 --- BBU tracking and analysis modules
-> Python main user interface ( Most upper-level program )
(Location: .../bsim/bbu/*)
1) test_run.py --- TOP interface file (formerly as run_examp_bbu.py)
--- Define all BBU and python parameters ( can be modified by user )
--- Create and Clean up the temporary directory
-> Python package (Call BBU Fortran codes; intermediate calculation, file organization):
(Location: .../bsim/bbu/python/bbu/*)
(Make sure .../bsim/bbu/pyhton/ is included in the $PYTHONPATH in ~/.bashrc)
1) bbu_main.py --- Parse BBU result. Calls other python codes.
2) find_threshold.py --- The core of the threshold calculation;
--- Prepare temporary files to run bbu / runs bbu_program.f90
3) drscan.py --- Prepares drscan files and plots. lat2.lat (temp) and thresh_v_trotb.txt will be created.
4) phase_scan.py --- Prepares drscan files and plots. lat2.lat (temp) and thresh_v_phase_PH.txt will be created.
-> Extra stand-alone programs
1) cut_HOM.py --- Accepts a directory full of wakefiled data files and a maximum number (N) of desired HOMs per file
and creates a new user-specified directory of corresponding files cut to include only the most influential N HOMs
2) collect_thresholds.py --- Summarizes the calculated threshold currents stored in the "bbu_thresholds_*" output files
Usually used after a complete grid submission
--- Output: bbu_combined_thresholds.txt
-> Local HOM assignment file
1) assignHOMs.bmad --- If this file exists in the directory which the user calls test_run.py
( not necessarily the directory where test_run.py locates ),
the HOM assignemnt from the original lattice will be over-written.
Unless the user has specified py_par['random_homs'] to be true
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