High Current Run I 2015 Feb 3 22:45 to Feb. 4 23:00 High Current Run II 2015 Feb 5 12:15 to Feb. 6 13:00 Current ~ 20 mA Approx. 40 trips, i.e. fast shutter closes ~ 75 % appear to be Gun HVPS tripping off ~ 25 % other ERL Injector Trip Studies

These are the fast signals we monitored during the two 24 hours runs: Gun HVPS voltage reading Cavity phases (we were biased toward looking at the phases rather than amplitudes because the “RF Field OK” signal seemed to only fail on amplitude). The output of the discriminator connected to the coupler PMTs A beam amplitude signal from a bpm before the dump (four BPM signals to an RF combiner, output of combine to a mixer to produce a 12.5 MHz signal which went to the scope) These signals were added part way through the two 24 hour runs: An analog signal from a coupler PMT (I don’t think the analog coupler PMT signal told us more than the discriminator output) A fast (log) amplitude and phase signal from a BPM in A1

Typical “Gun” Trip

don’t know what started this, beam amplitude is steady, cavity 2 trips off later 0.1 V = 5 degrees

beam signal at dump is affected by RF ?, dump quad detector closes shutter, no RF trips off (similar to Feb. 4 10:39 Trip) 0.1 V = 5 degrees

cause ?, beam steady, after shutter closes arc and pressure trips on cavity V = 5 degrees

subsequently arc and pressure trips, all cavities trip 0.1 V = 5 degrees

cavity response driven by beam disturbance ?, a later trip shows same behavior with no beam disturbance A2 closes shutter, all RF trips off 0.1 V = 5 degrees

cavity response driven by beam disturbance, dump quad detector closes shutter, no RF trips off, A1 Beam Phase, Amplitude 0.1 V = 5 degrees

Glitch in A1 beam intensity, cavity 1 closes shutter ?, cavity 1 trips off later (similar to Feb. 4 11:30:48 Trip) 0.1 V = 5 degrees