Recent Progress in the Superconducting RF Recent Progress in the - - PowerPoint PPT Presentation

Recent Progress in the Superconducting RF Recent Progress in the Superconducting RF Program at TRIUMF/ISAC Program at TRIUMF/ISAC

R.E. Laxdal, R.E. Laxdal, K. Fong, M. Laverty, A.

• K. Fong, M. Laverty, A.

Mitra Mitra, R. Poirier, V. , R. Poirier, V. Zvyagintsev Zvyagintsev 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

Linac SCRF Test Area

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

18.3 3 7.6 1.5 18.3 6 4.5 1.5 SCDTL 7.5 ≤ 30 1.5 0.153 IH-DTL 4.5 ≤ 30 0.153 0.002 RFQ

• ≤150→≤30

0.002 0.002 CSB (MV) (MeV/u) (MeV/u) Veff A/q Eout Ein Device

Stage 0 - 2005

E=4.5MeV/u A/q=6

S0

CSB

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

ISAC ISAC-

• II SC

II SC Linac Linac

Medium Beta Medium Beta Cryomodule Cryomodule

2x2x1m stainless steel box vacuum vessel LN2 cooled copper sheet used as thermal shield Mu metal between vacuum tank and LN2 shield Cold mass suspended from lid on three support pillars

Lid Assembly in Assembly Frame

Four cavities Ep=30MV/m One SC solenoid @ 9T Veff=4.3MV

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Forward Power Required for Ea=6MV/m and given bandwidth

50 100 150 200 250 300 350 400 450 500

• 20
• 10

10 20 Freq Error (Hz) Power (W) HBW=5Hz HBW=10Hz HBW=20Hz

RF Systems RF Systems

RF power

Provide useable bandwidth by

• vercoupling

Require Pf =200W at cavity for f 1/2=20Hz at Ea=6MV/m, β=200

Coupling loop

Developed LN2 cooled loop

<0.5W to LHe for Pf=250W

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

Forward power required for Ea=6MV/m and given bandwidth Coupling Loop Mechanical Tuner

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Tuner Response with Four Cavities

• 150
• 100
• 50

50 100 3 5 7 9

Time (Minutes) Tuner Pos'n

Tuner 1 Tuner 2 Tuner 3 Tuner 4 2 4 6 8 10 12 14 3 5 7 9

Time (Minutes) dP (Torr)

dP (Torr)

• Lever mechanism with zero backlash hinges

Lever mechanism with zero backlash hinges and stiff rod connected to precision linear motor and stiff rod connected to precision linear motor ( (Kollmorgan Kollmorgan) in air ) in air All four cavities locked to ISAC-II Specifications Ea=6MV/m (Ep=30MV/m) and 106.08MHz Pcav~6W, Pfor~250W, β~170 Helium exhaust valved off to force pressure 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 Cryomodule Cold Tests Cold Tests

First Cooldown (SCB3)

April 2004 Alignment and Cryogenic studies

SCB3 Cryomodule Assembly Before Test 2

Second Cooldown (SCB3)

June 2004 Rf studies (alignment check)

Third Cooldown (SCB3)

• Oct. 2004

Final rf studies Remote operation alpha acceleration

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Fourth Cooldown (SCB1)

March 2005 Alignment, Cryogenic, and rf

Cryomodule Static Load – Test 1, 2, 3

• April 25 – First cooldown
• No rf or solenoid cables
• 11W static load

Static Load - Test 1

10 20 30 40 50 4 5 6 7

Time (hours) Power (W)

20 40 60 80 100

He Level (%)

He Load (W) Cav1 (deg K) Cav2 (deg K) He Level (% )

Test 3 - Static Load

10 20 30 40 50 60 60 80 100 120 140 160 Time (minutes) Power (W) Helium Power (W) Helium Level (%)

• July 2 – Second cooldown
• Rf/solenoid/alignment cables
• 16W static load
• Nov. 3 – Third cooldown
• Final configuration
• 13W static load
• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Cryomodule Cryomodule Cooldown Cooldown

• 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

20 40 60 80 100 120 140 160 180 200 1 2 3 Time (Hours) Temp (degK) / Hel Flow (ltr/hr) Solenoid Cavity 1 Cavity 2 Cavity 3 Cavity 4 He Reservoir He Flow (ltr/hr)

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

the tolerance on solenoid and cavity misalignments are ±200 µm and ±400 µm respectively we have collaborated with INFN Milano on the development of a Wire Position Monitor for cold alignment with precision of 20 µm Stripline monitor attached to each device driven by rf signal along a reference wire

Cryomodule Alignment

WPM RF shield solenoid cavities

Wire Position Stripline Monitor WPM Monitors on Cavities

Optical target Optical target

Plan View

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Superconducting Solenoids Superconducting Solenoids

• Focussing

Focussing in the SC in the SC Linac Linac is provided is provided by superconducting solenoids (B by superconducting solenoids (B≤ ≤9T) 9T)

• End fringe fields controlled with active

End fringe fields controlled with active `bucking `bucking’ ’ coils (B coils (Bcavity

cavity≤

≤0.1T) 0.1T)

• Production Medium and high beta

Production Medium and high beta solenoids in fabrication at solenoids in fabrication at Accel Accel

• See table for specifications

See table for specifications

45cm 45cm 34cm 34cm 16cm 16cm Eff

• Eff. Length

. Length 3 3 5 5 4 4 Number Number 26mm 26mm 26mm 26mm 26mm 26mm Bore Bore 9T 9T 9T 9T 9T 9T Field Field High High β β Med Med β β Low Low β β

Prototype Solenoid at Accel

Axial Field 1 2 3 4 5 6 7 8 9

• 500
• 400
• 300
• 200
• 100

100 200 300 400 500 Z (mm) Fie ld (T) Axial Field

See ThP40

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Solenoid – Test 2

• Base Q’s measured before solenoid test
• Ramp up solenoid to 9T
• Cavities 2 and 3 on
• No quench of cavities or solenoid
• No change in cavity Q
• Cold mass warmed above transition
• Q’s measured after second cooldown
• No change; Q>1e9
• Residual field tolerable
• Field measurements after test showed

that some magnetization of environment

• ccured

Solenoid

Accel Solenoid Field

2 4 6 8 10 100 200 300 400

z(mm) Field (T)

200 400 600 800 1000

Field (Gauss)

Cavity See ThP40

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Magnetic Mapping of Magnetic Mapping of Cryomodule Cryomodule

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 See ThP40

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

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

* Data taken by Accel

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. See ThP40

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

( ) ( ) ( )

0.3

mag

R n B mGauss f GHz ∆ Ω ∆ = ⋅

1 .00E+07 1.00E+08 1.00E+09 1.00E+10 0.0E+00 3.0E+06 6.0E+06 9.0E+06 1.2E+07 1.5E+07 Nov.2 Nov.3 Nov.5 Nov.8 1 .00E+07 1.00E+08 1.00E+09 1.00E+10 0.0E+00 3.0E+06 6.0E+06 9.0E+06 1.2E+07 Nov.2 Nov.3 Nov.5 Nov.8

1.00E+07 1.00E+08 1.00E+09 1.00E+10 0.0E+00 3.0E+06 6.0E+06 9.0E+06 1.2E+07 Nov.2 Nov.3 Nov.5 Nov.8 1.00E+07 1.00E+08 1.00E+09 1.00E+10 0.0E+00 3.0E+06 6.0E+06 9.0E+06 1.2E+07 Nov.2 Nov.3 Nov.5 Nov.8

Field Increase

200 400 600 800 1000 1 2 3 4 Cavity # ∆ B (mGauss) Second Third Fourth

Cavity #1 Cavity #2 Cavity #3 Cavity #4 Cavities warm overnight but solenoid doesn’t

• On Day 1 and Day 2 the solenoid is hysteresis cycled
• On Day 3 no cycle and we get a large Q-drop

c c c TEST3: Q –curves of the cavities in the Cryomodule during four days rf test

Summary of Cavity Testing

Flat Cavities

• SCB1

– Cav 5√, 6√, 8√, 10√

• SCB2

– Cav 7√, 9√, 11√, 12√

Round Cavities

• SCB3

– Cav 1√, 2√, 3√, proto√

• SCB4

– Cav 13√, 4√, 16√ ,14x

• SCB5

– Cav 17√, 18√, 19√, 20

• Spare

– Cav 15x

10 8 Total OK 1 2 Retested OK 2 2 Failed 2 Untested 11 8 Tested 13 8 Total Number Round Flat

SCB1 SCB2 SCB3 SCB4 SCB5 Medium Beta Section See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

1.E+07 1.E+08 1.E+09 1.E+10 2 4 6 8 10 12 Ea (MV/m) Q cavity 1 cavity 2 cavity 3 cavity 4 cavity 5 cavity 6 cavity 7 cavity 8 cavity 9 cavity 10 cavity 11 cavity 12 cavity 13 cavity 14 cavity 16 7 Watts cavity 17 cavity 18

Initial Test Results Initial Test Results

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Cavity 11 Cavity 11-

• BCP 130

BCP 130µ µm, EP ~65 m, EP ~65-

• 150

150µ µm m

• Yields lower

Yields lower Qo Qo but less Q but less Q-

• slope and slightly higher

slope and slightly higher Q at high gradient Q at high gradient

• Early measurement shows effects of Q

Early measurement shows effects of Q-

• disease

disease Before EP After EP

TRIUMF/Argonne* Collaboration – Cold Test Results

* K. Shepard, M. Kelly, M. Kedzie

Qo vs Ea

1.00E+07 1.00E+08 1.00E+09 1.00E+10 2 4 6 8 10 12 Ea, MV/m Qo QoEP QoBCP QoEP2 Q7W ISAC-II specifications: Ea=6MV/m P=7W

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Before EP After EP

Qo vs Ea

1.00E+07 1.00E+08 1.00E+09 1.00E+10 2 4 6 8 10 12 Ea, MV/m Qo BCP+EP Q7W BCP BCP+Hand ISAC-II specifications: Ea=6MV/m P=7W

TRIUMF/Argonne* Collaboration – Cold Test Results

Cavity 7 Cavity 7-

• BCP 130

BCP 130µ µm, EP ~25 m, EP ~25-

• 75

75µ µm m

• Provides improvement but still evidence of Q

Provides improvement but still evidence of Q-

• disease

disease

* K. Shepard, M. Kelly, M. Kedzie See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Frequency Shift Frequency Shift for EP for EP

Cavity 11 Cavity 11 ∆ ∆f=+ f=+168 kHz 168 kHz Cavity 7 Cavity 7 ∆ ∆f= f=+110 kHz +110 kHz Simulation Results Simulation Results

– – Etch the top half by 100 Etch the top half by 100 microns microns

∆ ∆f= f=-

• 179 kHz

179 kHz

– – Etch bottom half by 100 Etch bottom half by 100 microns microns

∆ ∆f=+ f=+191 kHz 191 kHz

– – Etch 100 microns on all Etch 100 microns on all surfaces surfaces

∆ ∆f=+ f=+12 kHz 12 kHz * K. Shepard, M. Kelly, M. Kedzie

TRIUMF/Argonne* Collaboration

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Cavity Temperature Sensors Cavity Temperature Sensors

TS4 TS1 TS3 TS2 Four Temperature Sensors Installed on Cavity

• TS1 – bottom of inner conductor in

helium space

• TS2 – connected to bottom flange of

cavity

• TS3 - connected to coupling loop

flange

• TS4- connected to top cavity flange

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Cavity 11 Cavity 11-

• Cool

Cool-

• down Rate

down Rate

• Bake out at 368K for 50 hours
• Radiation cool from 360 to 210K in 50

hours

• LHe cool from 160K to 50K in <0.5hr

Cavity 11 - Second Cold Test

• 50

50 100 150 200 250 300 350 400 50 100 150 Time (Hours) Temp (degK) TS1 TS2 TS3 TS4

Cavity 11 First Test

• 50

50 100 150 200 250 300 350 400 50 100 150 Time (Hours) Temp (degK) TS1 TS2 TS3 TS4

• Bake out at 368K for 50 hours
• LN2 pre-cool to 160K for 22 hours
• For some part of the inner

conductor was at 77K

• LHe cool from 160K to 50K in <0.7hr

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

• May 4 - Cavity 17 was tested after a normal cooldown with LN2 precool
• May 6 – The cavity was warmed to 100K and held for 18 hours
• The marked Q-drop in the second test is direct evidence that cavity 17 (BCP cavity) has Q-

disease.

• May 12 - The cavity was warmed up and baked at 95C for 48 hours then radiation cooled for 48 hours

to 205K then fast cooled with helium to 4K

Cavity 17 Results

1.E+07 1.E+08 1.E+09 1.E+10 2 4 6 8 10 12 Ea (MV/m) Q

May 4 - LN2 precool May 6 - 100K (18hours) Q@7W May 12 - Fast Cooldown

Q-Disease in BCP Cavities

See TuP36

Other Q-disease cavities?

1.E+07 1.E+08 1.E+09 1.E+10 2 4 6 8 10 Ea (MV/m) Q

Cav17 - LN2 precool Q@7W Cavity 9 Cavity 12 Cavity 14 Cavity 7

Are there other cavities that may have poor test results due to Q-disease?

• Cavities 7(EP), 9, 12 and 14 may all be considered
• Most likely Q-disease induced during manufacture

Q-Disease in Other BCP Cavities?

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Q Q-

• disease summary

disease summary

1.E+07 1.E+08 1.E+09 1.E+10 5 10 15 20 25 30 80K < time < 150K (h) Qo

cav #8 cav #9 cav #10 cav #11 cav #12 cav #13 cav #14 cav #16 cav #7ep cav #11ep cav #11ep2 cav #17 cav #17-2 cav #17-3 cav #3 cav #2 cav #1 cav #4 cav #5 cav #6 cav #6-2

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Qo vs Ea

1.00E+07 1.00E+08 1.00E+09 1.00E+10 2 4 6 8 10 12 Ea, MV/m Qo Qo-July2005 Q7W Q-Febr2005 ISAC-II specifications: Ea=6MV/m P=7W

Cavity 9 Cavity 9

• First Test – LN2 pre-cool, evidence of Q-disease
• Second test – no LN2 pre-cool

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Cavity 12 Cavity 12

With and without Q-desease

1.00E+07 1.00E+08 1.00E+09 1.00E+10 2 4 6 8 10 12 Ea, MV/m Qo June15 Q7W March2 ISAC-II specifications: Ea=6MV/m P=7W

• First Test – LN2 pre-cool, evidence of Q-disease
• Second test – no LN2 pre-cool

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Qo vs Ea

1.00E+07 1.00E+08 1.00E+09 1.00E+10 2 4 6 8 10 12 Ea, MV/m Qo Qo2 Q7W Qo1 ISAC-II specifications: Ea=6MV/m P=7W

Cavity 14 Cavity 14

• First Test – LN2 pre-cool, evidence of Q-disease
• Second test – no LN2 pre-cool, hard Quench at 3MV/m

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Cavity Performance Statistics Cavity Performance Statistics – – 17 cavities 17 cavities

Distribution of peak surface field at Pcav=7W

• Three cavities show signs
• f Q-disease from LN2 pre-

cooling

• These cavities were

retested with fast cooldown

• Average peak surface field

at operating power is now 38MV/m corresponding to a voltage gain of 1.4MV/cavity

Ep (MV/m)

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Latest Summary Latest Summary

1.E+07 1.E+08 1.E+09 1.E+10 2 4 6 8 10 12 Ea (MV/m) Q

cavity 1 cavity 2 cavity 3 cavity 4 cavity 5 cavity 6 cavity 7 cavity 8 cavity 9 cavity 10 cavity 11 cavity 12 cavity 13 cavity 14 cavity 16 7 Watts cavity 17 cavity 18 cavity 19

See TuP36

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Phase Noise Diagnostic Phase Noise Diagnostic

• Add a low noise frequency synthesizer and FFT analyzer to self-excited

regulation system

• Set loop gain Gθ to minimum to keep phase detector in the linear range
• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Phase Noise Measurements Phase Noise Measurements

• Here the sampled spectra show the

suppression of phase noise below the regulation bandwidth when the phase loop is closed.

• resonance peaks can help diagnose

system

• 74 Hz – lowest cavity mode
• 48 Hz – mechanical fan in rf amplifier
• 3 Hz – cavitation boiling of LHe
• Wider scans of the phase noise spectra for

different cavities reveal other resonance modes as well as defects in the power amplifier of Cavity #3.

Alpha Particle Acceleration Alpha Particle Acceleration

• ISAC-II test cryomodule is outfitted with diagnostic boxes for and

aft separated from the main vacuum space by gate valves.

• Upstream box A contains 244Cm alpha source (5.8MeV but degraded

by containment foil to 2.8MeV)

• Downstream box B contains silicon detector for energy measurement
• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Expected Energy Gain Expected Energy Gain

• 0.99

0.99 0.92 0.92 0.74 0.74 0.47 0.47 TTF/TTF TTF/TTF0

• 2.14

2.14 1.99 1.99 1.60 1.60 1.01 1.01 ∆ ∆E E ( (MeV MeV) ) 9.59 9.59 1,2,3,4 1,2,3,4 7.45 7.45 1,2,3 1,2,3 5.46 5.46 1,2 1,2 3.86 3.86 1 1 2.85 2.85 Off Off E E ( (MeV MeV) ) Cavity Cavity

Beam 2.85MeV Cavity 1 3.86MeV Cavity 1,2 5.46MeV Cav 1,2,3 7.45MeV Cav1,2,3,4 9.59MeV

Medium Beta Cavities

• 6 MV/m, Leff=0.18m, Pcav=4W
• Epeak=30MV/m, Bpeak=60µT
• ∆V=1.08MV, β0=0.07
• α-particles A/q=2
• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

• Cavities set for Ea=6MV/m and

phase optimized for maximum acceleration

• Scan phase every 30deg and count

for 10 minutes to collect spectra

• Broad final energy spectra due to

unbunched, uncollimated beam with large initial energy spread

Test Results Test Results

9.4 9.4 7.4 7.4 5.8 5.8 4.2 4.2 ? ? Etest Etest ( (MeV MeV) ) 9.59 9.59 1,2,3,4 1,2,3,4 7.45 7.45 1,2,3 1,2,3 5.46 5.46 1,2 1,2 3.86 3.86 1 1 2.85 2.85 Off Off E E ( (MeV MeV) ) Cavity Cavity

4.2MeV 5.8MeV 7.4MeV 9.4MeV 2.85MeV

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Alpha Spectra Fitting Alpha Spectra Fitting

• Beam simulation code LANA was

used to model the alpha source and cryomodule acceleration

• Cavity phase and amplitude were

varied to obtain the best fit to the data

• Cavity settings produce a unique

spectral fingerprint so that V and φ can be determined unambiguously

• This method gives the following

gradients

5.8 5.8 5.6 5.6 5.8 5.8 5.0 5.0 Gradient Gradient (MV/m) (MV/m) 4 4 3 3 2 2 1 1 Cavity Cavity

• Average Ea=5.6MV/m within 6%
• f goal.
• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

ISAC Beam SCB1

Diagnostic box Helium Dewar

Test Configuration

Buncher

ISAC-II Vault

PS Rack Level 0 – refrigerator room Level 1– power supply room

SCB1 Vault Test

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Goals Goals

S S-

• bend commissioning

bend commissioning First operation of refrigerator by TRIUMF First operation of refrigerator by TRIUMF personnel personnel Test services/cabling performance from Test services/cabling performance from final location final location

– – Identify cross Identify cross-

• talk or environmental problems

talk or environmental problems

Test Test rf rf performance with refrigerator in performance with refrigerator in continuous delivery continuous delivery accelerate some beam accelerate some beam

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Helium Flow Schematic

SCB1 Cryomodule LHe Dewar Linde Coldbox Vaporizer To/From Compressor Heater Heater

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

RF Operation

24 hour

• Three cavities locked at ISAC-II

specification

• Ep=30MV/m, 106.08MHz,

Pfor=200W

• Cavity 1 has an in-vacuum open

circuit in the rf power feed

• 24 hour test at ISAC-II specifications

completed successfully

• Refrigerator run in continuous

feed cycle

• Frequency tuners effectively track rf

frequency to maintain lock over a large pressure variation in the helium space Tuner signals pressure

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell

Acceleration Acceleration – – July 7 July 7

Injected Injected 26

26Mg6+ from ISAC at 1.5MeV/u into SCB1

Mg6+ from ISAC at 1.5MeV/u into SCB1 Measured final energy with Measured final energy with Si Si detector detector Achieved 3.5MV acceleration from three cavities Achieved 3.5MV acceleration from three cavities – – Corresponds to average values of Corresponds to average values of Ep Ep=33.4MV/m, Bp=67mT (Ea= 6.7MV/m) =33.4MV/m, Bp=67mT (Ea= 6.7MV/m) – – Coupling beta 200, Pf=310W, Coupling beta 200, Pf=310W, Pcav Pcav=6W =6W – – One cavity not operational One cavity not operational SCB1 Acceleration

0.2 0.4 0.6 0.8 1 1.2 6 7 8 9 10 11 Energy (MeV/q) Initial Beam Cavity 2 on Cavity 3 on Cavity 4 on

• R. Laxdal, MoP06, Recent Progress in the SRF Program at TRIUMF/ISAC, SRF2005, July 11/05, Cornell