An investigation on the field emitted electrons in travelling wave accelerating structures
Abstract
An investigation about field emission and rf resonant discharges in travelling wave accelerating structures is presented. Resonant electron loading (multipactoring) and non-resonant dark-current are discussed, and starting from a very simple model based on the kinematics of the electrons in rf fields, frequency scaling laws for both multipactoring and dark-currents are found. Our predictions are checked by using the TW-TRAJ code in the case of a LIL-type accelerating structure. Results showing excellent agreement of simulations and experimental measurements up to 100 MV/m of accelerating field are reported. The TW-TRAJ code was extensively used to check the correctness of the frequency scaling laws for the electron loading found by using our naive model in homothetically scaled accelerating structures: the results of our analysis are reported. Last the results of simulations on a CLIC type structure operating at 30 GHz are reported; our analysis shows that no dark current would appear in a CLIC accelerating structure up to an accelerating field of 750 MV/m due to the wide opening of the irises of the accelerating wave guide.
- Publication:
-
Nuclear Instruments and Methods in Physics Research A
- Pub Date:
- August 1992
- DOI:
- 10.1016/0168-9002(92)90761-R
- Bibcode:
- 1992NIMPA.320....1B