IPHI RFQ Conditionning Overview of IPHI RF system

IPHI RFQ Conditionning Ø Overview of IPHI RF system Ø RF mesurements Ø Interlocks Ø RF Processing Strategy 1 Michel Desmons CEA/IRFU/SACM ESS meeting 27/november/2012

RF distribution and RFQ Voltage and Frequency Régulation Accelerator Phase Reference Line Reference Oscillator Command - control Low level RF Cooling Water Temperature Control Pmax =1000 k. W Pmax=1000 k. W DF = ± 1° Fk 1 - Fk 2 = constant DV / V = 1% Pk 1 / Pk 2 = constant 100 ke. V 100 m. A 300 k. W RFQ 910 k. W cavity 300 k. W 3 Me. V 100 m. A 290 k. W beam 2 Michel Desmons CEA/IRFU/SACM ESS meeting 27/november/2012

Ethernet Acquisitions Command/Control interface RF Synthetizer x 96 Multiplexer K 1 RF Interlocks RFQ RF Regulation K 1 RF mesurements x 11 RF mesurement conditionning K 2 RF mesurements x 11 Command/control RFQ RF mesurements K 2 RF Interlocks K 1 RF Regulation K 1 arc detectors K 2 RF Regulation K 2 arc detectors Interlocks synthesis K 1 RF mesurements (11 chanels) K 1 RFQ RF mesurements Arc Detector x 96 RFQ K 2 RF mesurements (11 chanels) K 2 RF window 3

22 RF mesurements with directionnal couplers on waveguides 6 Circulator 1 Klystron 1 Pre-Ampli 1 7 RF window #1 Magic T Load MT 1 1 2 3 4 5 Coaxial Water Load 6’’ 1/8 300 k. W 11 Load. CIRCU 1 Pre-Ampli 2 Klystron 2 Circulator 2 RF window #2 8 9 10 19 20 RF window #3 Magic T Load MT 2 14 15 16 17 Coaxial Water Load 6’’ 1/8 300 k. W 18 13 RF window #4 21 22 23 4 Load. CIRCU 2 casemate

96 RF mesurements with loops inside RFQ tuners Tuner Loop : 1 W Output RF power at nominal voltage after RFQ tuning : Calibration insitu of the pickups with 200 W input power on one RF port and matched load on the 3 other ports tuner A 11 Tuner F 11 beam 2 1 3 4 segment A segment B segment C segment D Tuner A 44 segment E segment F Tuner F 44 5 Michel Desmons CEA/IRFU/SACM ESS meeting 27/november/2012

RF mesurements conditionning Trigger input from waveguides Atténuator Filter 96 to 6 from RFQ pickups Détector multiplexer GPIB KEITHLEY switch system model 2750 to RF Interlocks Rack + Scope Monitoring 6 Michel Desmons CEA/IRFU/SACM ESS meeting 27/november/2012

RF interlocks Synoptic K 1 RF Interlocks PDIRkly PDIR 1 PDIR 2 PDIR 3 PREV 1 PREV 2 PREV 3 ARC Windows vacuum ARC extra RF Validation (in) Arc detectors interlocks K 2 RF Interlocks K 1 K 2 RFQ vacuum extra RF Validation (out) Trigger 7 Michel Desmons CEA/IRFU/SACM ESS meeting 27/november/2012

RF Interlocks ON +5 V 0 V OFF Interlock inibition at pulse start (10 to 30 us) RF Blanking at interlock trip (10 to 100 ms) OK +15 V 0 V KO 8 Michel Desmons CEA/IRFU/SACM ESS meeting 27/november/2012

Arc detector Ø Copy of LEP arc detector electronic board 1 s Timer (RF blanking) waveguide Optical fiber Sensitivity adjustment 9 Michel Desmons CEA/IRFU/SACM ESS meeting 27/november/2012

Electron detector Analog output (monitoring) 45 V bias Waveguide (vacuum side) 1 m. A threshold OK 0 V KO Bias TEE Pick-up CF 16 RF window waveguide (air side) 10 Michel Desmons CEA/IRFU/SACM ESS meeting 27/november/2012

RFQ RF processing Cooling water temperatures set to nominal values Feedback Loops settings (step 1 to step 3): • RFQ self-excited loop : ON • klystron Amplitude/Phase regulation : ON • RFQ amplitude regulation : OFF • RFQ frequency regulation : OFF 1. Start with short pulses (30 us min due to Amplitude/Phase feedback loop settling time) and 1 Hz repetition rate 2. Power Ramping up to nominal RFQ voltage controled by vacuum (RFQ and RF windows) ►Pressure<1 x 10 -6 mbar : RF power UP ► 1 x 10 -6 mbar<Pressure<5 x 10 -6 mbar : RF power DOWN ►Pressure>5 x 10 -6 mbar : RF power switched off and switched on again when Pressure<1 x 10 -6 mbar 3. New power ramping with progressive lengthening of RF pulse width, up to CW operation (detuning sensitivity can be mesured during this phase) 4. RFQ amplitude regulation : ON 5. Check of voltage stability (RFQ pickups) : if not OK, change of cooling water temperatures set points 6. RFQ frequency regulation ON 7. Beam ON (with/without RFQ frequency regulation) 11 Michel Desmons CEA/IRFU/SACM ESS meeting 27/november/2012