Coupling Schemes and Measurements for Multiple Eigenmode Application in Superconducting RF Guns

Superconducting electron sources are a promising candidate to meet the challenges of future electron accelerator, such as high average beam current and high peak brilliance at the same time. Compared to their normal conducting rf equivalent and due to the Meissner-Ochsenfeld effect, the solenoid for emittance compensation has to be placed far in front of the cathode. To solve this problem the use of transverse electric (TE) modes in parallel to the accelerating mode was proposed*. This contribution presents two suitable coupling schemes and first rf measurements at the warm and cold HZDR SRF gun cavity.
* V. Volkov, D. Janssen, Phys. Rev. ST Accel. Beams 11, 061302 (2008)