Recent results on the DARHT and AIRIX 4 MV ± 1%,3.5 kA electron beam injectors

The results of recent testing on both the DARHT and AIRIX electron beam injectors are presented. The injectors produce a 4.0 MeV, 3.5 kA, 60 nsec flat top, low emittance beam. Electron beam energy pulse shape fidelity was measured with both a CESTA and LANL spectrometer. Both spectrometers agreed to within 1.0%. The novel design of the CEST A spectrometer allowed the flatness of the electron energy waveform to be time resolved in detail on each pulse for the first time. Fine tuning, which produced a 4.0 MV ± 0.82% beam for 60 nsec on the AIRIX injector using the CESTA spectrometer is described. Normalized rms emittance values of 0.14–0.12 π cm·rad were obtained for both LANL and CESTA injectors. The improvements incorporated in the AIRIX injector developed through operating the DARHT injector are presented. Results of a 1000 pulse reliability test on the AIRIX injector are given which demonstrated a voltage reproducibility of ≤ 0.6% (spread) and command fire jitter of ≤ 0.5 nsec (1 sigma).