Recent Progress in the Superconducting RF Recent Progress in the Superconducting RF Program at TRIUMF/ISAC Program at TRIUMF/ISAC R.E. Laxdal, K. Fong, M. Laverty, A. K. Fong, M. Laverty, A. R.E. Laxdal, Mitra, R. Poirier, V. , R. Poirier, V. Zvyagintsev Zvyagintsev Mitra TRIUMF, Vancouver, Canada TRIUMF, Vancouver, Canada Outline: •Overview of ISAC-II Linac •Medium Beta Cryomodule •Summary of SC solenoid experience •Cavity Testing Results •Acceleration Studies R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
SCRF Test Area Linac R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
Stage 0 - 2005 E=4.5MeV/u A/q=6 Device E in E out A/q V eff (MeV/u) (MeV/u) (MV) ≤ 150 →≤ 30 CSB 0.002 0.002 - ≤ 30 RFQ 0.002 0.153 4.5 ≤ 30 IH-DTL 0.153 1.5 7.5 S0 SCDTL 1.5 4.5 6 18.3 1.5 7.6 3 18.3 CSB R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
ISAC- -II SC II SC Linac Linac ISAC
Medium Beta Cryomodule Cryomodule Medium Beta � 2x2x1m stainless steel box vacuum vessel � Four cavities Ep=30MV/m � LN2 cooled copper sheet used as thermal shield � One SC solenoid @ 9T � Mu metal between vacuum tank and LN2 shield � V eff =4.3MV � Cold mass suspended from lid on three support pillars Lid Assembly in Assembly Frame R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
RF Systems RF Systems Forward power required for Ea=6MV/m and given Forward Power Required for Ea=6MV/m and given bandwidth bandwidth � RF power 500 450 � Provide useable bandwidth by 400 overcoupling 350 Power (W) 300 HBW=5Hz 250 HBW=10Hz � Require P f =200W at cavity for f 1/2 =20Hz 200 HBW=20Hz at E a =6MV/m, β =200 150 100 � Coupling loop 50 0 -20 -10 0 10 20 � Developed LN2 cooled loop Freq Error (Hz) � <0.5W to LHe for P f =250W Coupling Loop Mechanical Tuner � Mechanical tuner � Precise (0.3~Hz), fast (>50Hz/sec) tuner with dynamic range of 8kHz and coarse range of 32kHz � Tuning plate � Spun, slotted, `oil-can’ tuning plate to improve tuning range R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
Tuner Response with Four Cavities 14 dP (Torr) 12 10 dP (Torr) 8 6 4 2 0 3 5 7 9 Time (Minutes) Lever mechanism with zero backlash hinges � � Lever mechanism with zero backlash hinges 100 Tuner 1 and stiff rod connected to precision linear motor and stiff rod connected to precision linear motor Tuner 2 ( (Kollmorgan Kollmorgan) in air ) in air 50 Tuner 3 Tuner 4 � All four cavities locked to ISAC-II Tuner Pos'n 0 Specifications 3 5 7 9 � Ea=6MV/m (Ep=30MV/m) and -50 106.08MHz -100 � P cav ~6W, P for ~250W, β ~170 -150 � Helium exhaust valved off to force pressure Time (Minutes) fluctuation R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
Coupling Loop with Direct Cooling Coupling Loop with Direct Cooling � Developed from INFN Legnaro adjustable coupling loop � Modifications � Stainless steel body for thermal isolation � Copper outer conductor thermally anchored to copper LN2 cooled heat exchange block � Aluminum Nitride dielectric inserts thermally anchor the inner conductor to the outer conductor � Removed fingerstock to control microdust � Achieved <0.5W helium heating with Pf=250W R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
Cryomodule Cold Tests Cold Tests Cryomodule � First Cooldown (SCB3) SCB3 Cryomodule Assembly Before Test 2 � April 2004 � Alignment and Cryogenic studies � Second Cooldown (SCB3) � June 2004 � Rf studies (alignment check) � Third Cooldown (SCB3) � Oct. 2004 � Final rf studies � Remote operation � alpha acceleration � Fourth Cooldown (SCB1) � March 2005 � Alignment, Cryogenic, and rf R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
Cryomodule Static Load – Test 1, 2, 3 Static Load - Test 1 •April 25 – First cooldown 50 100 He Load (W) •No rf or solenoid cables Cav1 (deg K) 40 80 Cav2 (deg K) He Level (% ) He Level (%) Power (W) 30 60 • 11W static load 20 40 •July 2 – Second cooldown 10 20 •Rf/solenoid/alignment cables 0 0 4 5 6 7 Time (hours) • 16W static load Test 3 - Static Load •Nov. 3 – Third cooldown Helium Power (W) 60 Helium Level (%) 50 •Final configuration 40 Power (W) 30 • 13W static load 20 10 0 60 80 100 120 140 160 Time (minutes) R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
Cryomodule Cooldown Cooldown Cryomodule • Cryomodule pre-cooled with LN2 and further cooled with LHe through a parallel arrangement of small tubes, `spider’, from common manifold •Manifold and `spider’ worked well to cool cavities uniformally •The solenoid, due to larger mass and different geometry, takes ~10 hours @ 75ltr/hr to cool Cool-down 200 Solenoid Temp (degK) / Hel Flow (ltr/hr) 180 Cavity 1 160 Cavity 2 140 Cavity 3 Cavity 4 120 He Reservoir 100 He Flow (ltr/hr) 80 60 40 20 0 0 1 2 3 Time (Hours) R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
Cryomodule Alignment WPM Monitors on Cavities � the tolerance on solenoid and cavity misalignments are ± 200 µ m and ± 400 µ m respectively � we have collaborated with INFN Milano on the development of a Wire Position Monitor for cold alignment with precision of 20 µ m � Stripline monitor attached to each device driven by rf signal along a reference wire Plan View Optical target WPM RF shield Wire Position Stripline Monitor cavities solenoid Optical target R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
See ThP40 Superconducting Solenoids Superconducting Solenoids Prototype Solenoid at Accel � Focussing Focussing in the SC in the SC Linac Linac is provided is provided � ≤ 9T) by superconducting solenoids (B ≤ by superconducting solenoids (B 9T) � End fringe fields controlled with active End fringe fields controlled with active � ≤ 0.1T) cavity ≤ `bucking’ `bucking ’ coils (B coils (B cavity 0.1T) � Production Medium and high beta Production Medium and high beta � solenoids in fabrication at Accel Accel solenoids in fabrication at � See table for specifications � See table for specifications Axial Field Low β β Med β β High β β 9 Low Med High 8 7 Field 9T 9T 9T Field 9T 9T 9T 6 Bore 26mm 26mm 26mm 5 Bore 26mm 26mm 26mm Fie ld (T) Axial Field 4 Number Number 4 4 5 5 3 3 3 2 Eff. Length Eff . Length 16cm 16cm 34cm 34cm 45cm 45cm 1 0 -500 -400 -300 -200 -100 0 100 200 300 400 500 Z (mm) R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
See ThP40 Solenoid – Test 2 •Base Q’s measured before solenoid test Cavity •Ramp up solenoid to 9T Solenoid •Cavities 2 and 3 on •No quench of cavities or solenoid •No change in cavity Q •Cold mass warmed above transition Accel Solenoid Field •Q’s measured after second cooldown 10 1000 8 800 •No change; Q>1e9 Field (Gauss) Field (T) 6 600 4 400 •Residual field tolerable 2 200 •Field measurements after test showed 0 0 0 100 200 300 400 that some magnetization of environment z(mm) occured R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
See ThP40 Magnetic Mapping of Cryomodule Cryomodule Magnetic Mapping of Mapped the internal magnetic field for 1. SCB3 after solenoid powered then warmed (no hysteresis cycle) 2. SCB1 before powering the solenoid 3. SCB1 after powering the solenoid and with hysteresis cycle Hysteresis cycle required to reduce memory of solenoid R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
See ThP40 Frozen Flux Frozen Flux Mapping data* for ISAC-II Solenoid � Solenoid is brought to 9 T and a) Ramped to zero with no cycle at 4K b) Taken to zero through hysteresis cycle at 4K c) Ramped to zero and warmed to 20K Frozen flux in solenoid produces a large (20G) field in cavity region when no hysteresis cycle is used. Cycling the magnet does reduce the field at the cavity but only warming the solenoid can eliminate the field. * Data taken by Accel R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell
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