Observations of Beam Filamentation at SLM5F02

in SimulationJuly 22, 2011

C. Tennant

Procedure• PARMELA model of gun

– Drive laser parameters based on measurements, assumes ideal distribution– 350 keV DC photocathode gun– Bunch charge of 135 pC, push 300K particles

• PARMELA model of merger– Use Excel (no space charge) to set quads for match to linac– Tweak quads to improve match in PARMELA (with space charge)

• PARMELA model of the linac (acceleration)– Accelerate 10° before crest– Space charge effects still appreciable in first module, use Excel to set

transverse match in the triplets (where space charge is small)• elegant model of the recirculator

– include 1D CSR model and implement “csrdrifts” (allows CSR wake to propagate beyond dipole)

– Run to middle of second p-bend SLM5F02

Recall: Beam-based Measurements

(view in Slideshow mode to view animated GIF)

st,wiggler = 418.7 fsunder-compressed

st,wiggler = 343.7 fsunder-compressed

st,wiggler = 269.2 fsunder-compressed

st,wiggler = 195.5 fsunder-compressed

st,wiggler = 126.0 fsunder-compressed

st,wiggler = 73.9 fsfully compressed

st,wiggler = 83.0 fsover-compressed

st,wiggler = 142.2 fsover-compressed

st,wiggler = 213.6 fsover-compressed

st,wiggler = 288.3 fsover-compressed

st,wiggler = 364.6 fsover-compressed

Energy and st vs QT2F08/9 Strengthover-compressedunder-compressed