1. RF Safety Discussion Derun Li/Bob Rimmer Center for Beam Physics Lawrence Berkeley National Laboratory SRF Institute, JLab

2. Hazards & Mitigations High Voltage –Usually fully contained in interlocked enclosure RF radiation –Survey, configuration control, WG overpressure X-rays –Shielding, monitors, interlocked access (PPS) Vacuum implosion (e.g. ceramic windows, foils) –Mechanical barriers, redundancy, procedures Arc –Fast arc detection, reflected power, vacuum

3. MICE Cavity Conditioning Before turning on high power RF –Cable calibrations (safety related) Power measurements (for safety interlock): forward and reflected power –Low power RF measurements: frequency, coupling and Q (may be used to calculate critical quantities) –Interlock checkout Arc detectors have to be verified (using test light and see if it triggers the interlock) Vacuum interlock: break vacuum measurement circuits RF window temperature interlock (water flow, infrared etc.) Water cooling system interlock (flow switch or “klixon”) –Visual inspection and survey for RF leaks if necessary (start at low power, maybe into a short circuit)

4. RF safety cont. Other inputs into RF “permissive” –Pressurized waveguide interlock –Radiation monitor interlock –PSS chain –LLRF “heartbeat” –Hydrogen safety system? –Etc. Magnetic field interlock PSS system should have it’s own checkout procedure Area search or sweep

5. MICE cavity conditioning General process –Go slowly –Condition couplers if needed (de-tune cavity) –Ramp voltage/pulse length with magnets off –Control ramp rate with vacuum up to gradient –Increment magnetic field & repeat Don’t get impatient ( computers are better at this ) –May sit in multipacting bands for a while –May take a while to condition at high gradient –Do not raise vacuum trip point to “help things along a bit”

6. Post-conditioning Relax & Enjoy Monitor trip rate pay attention to changes Cool some muons Write papers Build neutrino factory Condition a lot more RF systems Measure Higgs Retire somewhere warm and sunny