Simulation of beam gas coulomb scattering in HALS
  In conventional research on the beam gas coulomb scattering (BGCS), only the related beam lifetime using the analytical method is studied. In this paper, using the PIC-MCC method, we not only simulated the beam lifetime but also explored the effect of BGCS on the beam distribution. In order to better estimate the effect on particle distribution, we study the ultra-low emittance electron beam, here we choose the HeFei Advanced Light Source (HLAS). By counting the lost particles in a certain time, the corresponding beam lifetime we simulated is 5.1078h/14.5507h in x/y, which is very close to the theoretic value (5.0555h /13.7024h in x/y). By counting the lost particles relative to the collided particles, the simulated value of the loss probability of collided particles is 1.3228e-04, which is also very close to the theoretical value (1.3824e-04). Besides, the simulation shows there is a tail in the transverse distribution due to the BGCS. The close match of the simulation with theoretic value in beam lifetime and loss probability indicates our simulation is reliable. 
Yu Lu-Xin, Gao Wei-Wei, Wang Lin, Li Wei-Min
physics.acc-ph