Influence of structural parameters of dielectric wall accelerator structure on wake field

To study the beam instability caused by wake field effect, a dielectric wall accelerator module model consisting of symmetric pulse forming line, micro-stacked insulator and conductor layer was established. The finite integral method was used to simulate the wake field in the accelerating structure of dielectric wall accelerator (DWA) for high-current electron beam, wake potential and wake field impedance were calculated for the single and two accelerating units. Structural parameters of distance between two modules, thickness of metal and dielectric constant of insulator in micro-stacked insulator were changed to study the influence of different parameters on wake field. The results shows the wake potential and wake field impedance was small in x, y direction and different structural parameters can influence the wake field effect. Also it proved the advantage of accelerating cavity length and continuity in the DWA structure.