A new phsical model

Coaxial Resonator Tranverse Virtual Cathode Oscillator without appliedmagnetic field has been proPOsed in this paper. By means Of particle-in-cell simulation method its characterswere investigated. We defined a new concept-starting c

n

t density which will cause the stable oscillatingin the paper. A relationship between the oscillating freqUency and injected c

n

t density etc. are obtainedthrough simulation. We also analyzed two cases: the relativistic electron beam is injected from inner conductorand from outer conductor.The effect on virtual cathode oscillation was first taken into consideration with energyspread of the electron beam. The simulation results indicate that the new physical model has many advantages forpractical application.