Vertical Test System and T-mapping/X-ray-mapping at KEK-STFY. Yamamoto, H. Hayano, E. Kako, S. Noguchi, H. Sakai, M. Satoh, T. Shishido, K. Umemori, K. Watanabe (KEK, Japan)

[SRF2009@Berlin; TUPPO 038]

Vertical Test System at STF

A new vertical test facility was built in KEK-STF (Superconducting rf Test Facility) and in operation since July/2008. After the commissioning tests using AES#001 cavity which was on loan from FNAL, vertical test was routinely started for S1-Global project at KEK-STF. At the same time, a new T-mapping system was introduced for the identification of the heating location at the thermal quenching, which has 352 carbon resistors and is capable of more certainly identifying that, compared to the original T-mapping system. Recently, a new X-ray-mapping system is also completed.

Abstract

T-mapping/X-ray mapping System & Results

Commissioning TestAES#001 cavity was used, which was on loan from FNAL.

Successful!

Pinpoint attachment at suspicious spot

Suspicious spots at #3 cell

Suspicious spots

Summary

Content Feature

Cryostat 4m height, φ520mm, 10W (static loss)

Pumping system Rotary pump (4,000ℓ/min) x 2, Mechanical booster pump (15,000ℓ/min) x 2

Radiation Shielding 16cm thickness, Iron plate, Movable/Fixed type

High Power RF Amplifier Max. 400W, Min. 100W, 1240~1310MHz, Stability: 3%

Cavity Hanger Stand 3m height, Setting for 4 cavities

Data Acquisition System LabVIEW (present), EPICS (future)

Content Feature

T-mapping 352 carbon resistors (Allen-Bradley, 50 and 100Ω)

X-ray-mapping 142 PIN diodes (HAMAMATSU, S1223-01)

Sampling time 0.1sec

Data logger MX100/MW100 (YOKOGAWA)PXI2501/4071/6225 (National Instruments)

DAQ system EPICS (future)MHI#5

Summary of T-mapping result at STFcavity # of V.T. Eacc, max [MV/m] heating cell

@π modecause of limitation

for π modeheating cell @other pass-band modes

radiation level @Eacc, max[μSv/h]

AES#001 2nd 15.7 #3 found defect #3@5, 6, 8π/9 464

AES#001 3rd 21.8 #3 found defect #5 & #8@3π/9#3@5, 6, 8π/9

>1000

MHI#5 1st 27.3 #5 defect or contamination

#5@3π/9#1 & #9@4π/9

>1000

MHI#5 2nd 19.7 #8 defect or contamination

#8@3, 4, 8π/9#3@5π/9

#1 & #6@6π/9#5@7π/9

143

MHI#5 3rd 27.1 #5 defect or contamination

#5@3, 5, 7π/9#6@4, 6π/9

303

MHI#6 1st 25.7 #7 field emission #5@3π/9 >1000

MHI#6 4th 19.6 #9 multipacting(?)

#5@3π/9#9@4~8π/9

0

MHI#6 5th 22.1 ? cable breakdown #1@6π/9 56000

MHI#7 1st 16.5 #1 field emission #1@5~8π/9#4@4π/9#2@3π/9

3220

MHI#8 1st 16.0 #2 defect or contamination

#2@3, 4, 8π/9#3@5, 6π/9#1@7π/9

268

MHI#9 1st 25.0 #9(#2)

field emission #2@3, 4π/9#5@5π/9

#9@7, 8π/9

>99000

1st power rise @π mode

2nd power rise @π mode

MHI#9

Equator of #9 cell

Equator of #2 cell

T-mapping X-ray-mapping

π π8π/97π/9

6π/9

5π/9

4π/9

3π/9

The new vertical test facility was completed at STF and it is routinely used without any trouble. The commissioning test for the system check was successful by using the AES#001 cavity. The T-mapping and X-ray-mapping system was completed and the heating location at the quenching was perfectly detected. There was a correlation between the heating location and the X-ray emission site, when the cavity has a heavy field emission. In the near future, a new DAQ system using EPICS will be introduced, which is under developing.