Investigating of electrons bunching in a Penning trap and accelerating   process for CO2 gas mixture active medium
  In the presence of an active medium incorporated in a Penning trap, the moving electrons can become bunched, as they get enough energy, they escape the trap forming an optical injector. These bunched electrons can enter next PASER section filled with the same active medium to be accelerated. In this paper, electron dynamics in the presence of gas mixture active medium incorporated in a penning trap is analyzed by developing an idealized 1D model. We further evaluate the energy exchange occurring as the train of electrons traversing the next PASER section. The results show that the oscillating electrons can be bunched at the resonant frequency of the active medium. The influence of the trapped time and the population inversion are analyzed, which shows that the longer the electrons are trapped, the more energy from the medium the accelerated electrons get, and with the increase of the population inversion, the decelerated electrons virtually unchanged but the accelerated electrons more than double their peak energy values. What is more, the simulation results show that the gas active medium need lower population inversion to bunch the electrons compared to the solid active medium. So the experimental condition is easy to be achieved. 
Xiu-fang Tian and Cong-feng Wu and Qika Jia
physics.acc-ph physics.plasm-ph