Plasma Wakefield/STFC Summer School 2022 Poster

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Simulation of short driver bunches. Beams are defined directly within the configuration and beamfiles run through lem.py for diagnostics.

(LCODE configuration takes m/q, but resulting beamfiles are in q/m).


Driver Density: Long vs Short Proton Bunch
Run Number Base Configuration Window Width Window Length q/m Total Weight (pC) LCODE ampl LCODE Beam Current LCODE Beam Length Beam Length (um) Energy (approx) (GeV) Comments
1 short_bunch - DAC 3 10 1.0 -2045.504558 1 -3.6 0.1 3.63 30 Default DAC short_bunch.cfg
2 short_bunch - DAC 3 10 0.00054 -2045.504558 1 -3.6 0.1 3.64 30 Only change made to cfg m/q for protons. Ez plots for 1 and 2 are identical.
3 short_bunch - DAC 3 20 1.0 -2045.504558 1 -3.6 0.1 3.64 30 Plot x-range increases with window length increase.
4 short_bunch - DAC 3 100 1.0 -2045.504558 1 -3.6 0.1 3.63 30 Expecting Ez fall off with distance. Do observe this.
5 short_bunch - DAC 3 100 0.00054 -2045.504558 1 -3.6 0.1 3.64 30 Checking to see if Ez attenuation with distance is different for q/m=1/1836 (proton ). Identical plots.
6 short_bunch - DAC 3 20 0.00054 -2045.504558 -1 -3.6 0.1 3.64 30 Can compare this with run 3 as mass not impacting currently. Identical despite ampl=-1 meaning should be opposite charge. Will set this directly in m/q next.
7 short_bunch - DAC 3 20 1.0 -2045.504558 1 -3.6 0.1 3.63 30 Despite setting m/q=1 in cfg, lem still shows positive and so results identical to run 3.
8 short_bunch - DAC 3 20 1.0 -2045.504558 -1 -3.6 0.1 3.63 30 Keeping m/q as negative and making ampl=-1. Still no change. It seems (from previous knowledge) only changing the sign of the beam current in cfg makes a difference to m/q sign.
9 short_bunch - DAC 3 20 1.0 2045.504558 1 +3.6 0.1 3.63 30 Return to run 3 parameters but set current to positive. Saying q/m is +1 still, but total weight is now positive, suggesting previous runs have been negative species and this is positive.
Run Number Base Configuration Window Width Window Length q/m Total Weight (pC) LCODE ampl LCODE Beam Current LCODE Beam Length Beam Length (um) Energy (approx) (GeV) Comments
1 short_bunch - DAC 3 10 0.00054 total weight 1.0 3.6 0.1 beam length 30
2 short_bunch - DAC 3 10 0.00054 -2045.504558 1 3.6 0.1 beam length 30