Beam Test of a Superconducting Cavity for the Fermilab High-brightness Electron Photo-injector

An electron photo-injector facility has been constructed at Fermilab for the purpose of providing a 14–18 MeV electron beam with high charge per bunch (8 nC), short bunch length (1 mm RMS), and small transverse emittance [1]. The facility was used to commission a second-generation photo-cathode RF gun for the TeSLA Test Facility (TTF) Linac at DESY [2, 3]; in the future, the Fermilab electron beam will be used for R & D in bunch length compression, beam diagnostics, and new acceleration techniques. Acceleration beyond 4 MeV is provided by a 9-cell superconducting cavity (see Figure 1). The cavity also provides a longitudinal position-momentum correlation for subsequent bunch length compression. We report on the RF tests and a first beam test of this cavity.