Zhu, XW (reprint author), CAS, Inst High Energy Phys, Beijing 100039, Peoples R China.
We present a beam dynamics simulation study on 1.6 cell,high gradient W-Band photocathode RF gun which is capable of generating and accelerating 300pC electron bunch. The design system is made up of 91.392GHz photocathode RF gun and 91.392GHz travelling wave linac cells. Based on the numerical simulation using SUPERFISH and PARMELA and the conventional RF linac scaling law,the design will produce 300pC at 1.74MeV with bunch length 0.72ps and normalized tranverse emittance 0.55mm mrad. We study the beam dynamics in high frequency and high gradient;due to the high gradient,the ponderomotive effect plays an important role in beam dynamics; we found the ponderomotive effect still exist with only the fundamental space harmonics (synchrotron mode) due to the coupling of the transverse and longitudinal motion.