1. MICE RF Module Safety Steve Virostek Lawrence Berkeley National Laboratory MICE Collaboration Meeting February 12, 2005

2. RF Module Safety Steve Virostek - LBNLPage 2 Introduction RF Module safety plan and hazard analysis is in the preliminary stages of development Safety issues will be addressed by the MICE Design and Safety Review Group Approach will be consistent with safety planning under way for the AFC Module Hazards are being identified during initial phase Upcoming tasks: perform a hazard analysis and develop the safety document

3. RF Module Safety Steve Virostek - LBNLPage 3 RF Module Overview Cryo-cooler RF Couplers Support Structure Coupling Coil Vacuum Vessel RF Cavity Vacuum Pump/Manifold Be Window

4. RF Module Safety Steve Virostek - LBNLPage 4 RF Module Safety Topics X-rays and RF fields Magnetic fields Beryllium windows Coupling coil hazards Magnetic loads Vessel structural integrity Cavity sparking RF coupler windows Proximity to AFC Module Cooling water in vacuum

5. RF Module Safety Steve Virostek - LBNLPage 5 Preliminary Hazard Assessment X-rays and RF fields Radiation hazard to personnel during operation Shielding to be incorporated along the beamline RF interlocks prevent access during operation Coupling coil hazards Vessel rupture; magnet lead voltages; quenching issues Coils are vacuum insulated in their own vessel designed in accordance with the pressure vessel code Coil design includes appropriate quench protection that will limit the magnet lead voltages to 10 V

6. RF Module Safety Steve Virostek - LBNLPage 6 Preliminary Hazard Assessment Beryllium windows Hazardous material; thin window rupture hazard Unlikely to produce airborne particles Connection through vacuum manifold prevents differential pressure on windows Magnetic Fields Magnetic field hazard to personnel during operation Shielding to reduce fields in publicly accessible areas Interlocks prevent access during operation

7. RF Module Safety Steve Virostek - LBNLPage 7 Preliminary Hazard Assessment Magnetic Loads Large magnetic forces are reacted to the module vessel during operation and various quench scenarios Structural FEA used to design load carrying components Unbalanced loads on RF/AFC Module assembly will be reacted to the floor through RF Module support Vessel structural integrity Vessel subject to vacuum & possible overpressure loads Design will be per the appropriate pressure vessel code Pressure relief valve prevents excessive overpressure

8. RF Module Safety Steve Virostek - LBNLPage 8 Preliminary Hazard Assessment Cavity Sparking Sparking, multipactoring & high RF fields produce more dark current and extra thermal load on absorbers Heat load is estimated to be less than a few watts Monitor with vacuum gages and spark detectors RF coupler windows Ceramic window failure can vent the vessel and cavities Catastrophic failure is unlikely; usual mode is a crack resulting in a slow leak (no shockwave, easily detected) Pressurized N 2 will prevent O 2 from entering system

9. RF Module Safety Steve Virostek - LBNLPage 9 Preliminary Hazard Assessment Proximity to AFC module Be windows are adjacent to AFC modules Window fracture would exert no shockwave or vacuum loads on the absorber (no window differential pressure) RF power can be shut down very quickly Cooling water in vacuum Water line rupture could cause overpressure in vessel Vacuum vessel contains continuous tubes only – a small leak is much more likely than a full rupture Detect w/vacuum gages (PRV, RF interlock, water valves)