Transcript Tracking Simulation

Observations of Beam
Filamentation at SLM5F02
in Simulation
July 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 fs
under-compressed
st,wiggler = 343.7 fs
under-compressed
st,wiggler = 269.2 fs
under-compressed
st,wiggler = 195.5 fs
under-compressed
st,wiggler = 126.0 fs
under-compressed
st,wiggler = 73.9 fs
fully compressed
st,wiggler = 83.0 fs
over-compressed
st,wiggler = 142.2 fs
over-compressed
st,wiggler = 213.6 fs
over-compressed
st,wiggler = 288.3 fs
over-compressed
st,wiggler = 364.6 fs
over-compressed
Energy and st vs QT2F08/9 Strength
under-compressed
over-compressed