HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

1KEK

Crab Cavity- Cryogenics KEKB Crab Cavity Group- presented by NAKAI Hirotaka

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

2Overview

KEK

Crab cavity cryostat
Calorimetric measurements
Static heat loss of cryostat
Unloaded Q-factor of crab cavity

Cryogenic system monitoring

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

3KEKCrab Cavity Cryostat

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

KEK

4Cryostat Design Concept
Jacket-type liquid helium vessels
Coaxial coupler with bellows forfrequency tuning
Stub support for long coaxial coupler
for mechanical support and cooling ofcoaxial coupler tip

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATIONKEKTop View

5

Cryostat Conceptual Design
RF Input coupler

Frequency Tuningby Adjusting Distance

Magnetic Shield(Jacket Type)

StubSupport

HOM
Absorber
I.D. 240

Coaxial Coupler

I.D.100

Bellows
Liq. He
RF Monitoring
PortKEKB Review Committee/20070319

Liq. HeHOMAbsorber

Crab Mode
Reject Filter(Notch Filter)

80 K Liq. Nitrogen Shield

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATIONKEK6Schematic Drawing of Cryostat

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATIONKEK7

HER Crab Cavity Cryostat

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATIONKEK8LER Crab Cavity Cryostat

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION9KEKCalorimetric Measurements

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

KEK

10

Heater in Helium Jacket

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

KEK

11

Static Loss of Cryostat

HER

20061117
Heater [W] Duration [min.] Coupler [L/min.] Coax. [L/min.] Bellows [L/min.] Total [L/min.] Q-flow [W] Total Loss [W] Static Loss [W]028
3139.5
157.5300
18.67
20203137.5
157.5
298
18.54
50.00
31.46
40
153139.0
158.030018.67
46.15
27.48
0
273
137.0
156.0
296
18.42
20
203
137.0
157.0
297
18.48
57.14
38.66
40
15
3
138.5
158.5
300
18.67
50.00
31.33
Average
18.57
50.82
32.25

LER

20061223
Heater [W] Duration [min.] Coupler [L/min.] Coax. [L/min.] Bellows [L/min.] Total [L/min.] Q-flow [W] Total Loss [W] Static Loss [W]
032
4
98.7
137.9
240.6
14.97
20
214
99.5
142.0
245.5
15.28
38.18
22.90
40
164
101.2
117.2
222.4
13.84
40.00
26.16
0
32
4
99.3
142.0
245.3
15.26
20
22495.8149.4
249.2
15.51
44.00
28.49
40
164
96.5
125.0
225.5
14.03
40.00
25.97
Average
14.82
40.55
25.73

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

12Unloaded Q-Factors of HER

KEK1010

Operation Voltage

Q0

HER

109
20060614
20061115
20061116
20061117
20051220(Vertical Meas.)
108
0.0

0.5

1.0

1.5
V

kick

KEKB Review Committee/20070319

2.0

2.5

3.0

[MV]
NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

13Unloaded Q-Factors of LER

KEKQ01010

LEROperation Voltage

10920061222
20061223
20060113(Vertical Meas.)
108
0.0

0.5

1.0

1.5

2.0

2.5

3.0

Vkick [MV]KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

14

KEK

Monitoring Devices
in Cryogenic System

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

15

Monitoring Devices

KEK

Thermometers
Platinum-Cobalt alloy resistance thermometer(Pt-Co RTD) for liquid helium temperature
Copper-Constantan thermocouple for liquid
nitrogen temperature

Superconducting liquid helium level sensor
Pressure transducer
Heater for heat load compensation
Vacuum gauges
Cold cathode gauge (CCG)
Pirani gauge
KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

16

Devices in Helium Jackets

KEK

Helium Jacket
Pressure Transducer

Liquid Helium
Level Sensor

Heater Temperature(Thermocouple)

Cavity Temperature(Pt-Co RTD)
Heater Temperature(Thermocouple)

Helium Jacket
Temperature (Pt-Co RTD)KEKB Review Committee/20070319

Helium Jacket
HeaterHelium Jacket
Temperature(Pt-Co RTD)

Helium Jacket
HeaterNAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

KEK17

Devices in Vacuum Vessel

Input Coupler Flange
Temperature(Pt-Co RTD)
Large Beam Pipe
Temperature(Thermocouple)

Liquid Nitrogen Inlet Temperature(Thermocouple)
Liquid Nitrogen Outlet Temperature(Thermocouple)
Bellows Tubing
Temperature(Pt-Co RTD)
Small Beam Pipe
Temperature(Thermocouple)

Coaxial Coupler Tubing
Temperature(Pt-Co RTD)KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATIONKEK18

Devices at External Tubing
Input Coupler Cooling Gas
Temperature(Thermocouple)

Safety Valve
Temperature(Thermocouple)

Coaxial Coupler CoolingGas Temperature(Thermocouple)

Rapture Valve
Temperature(Thermocouple)

KEKB Review Committee/20070319

Bellows Cooling Gas
Temperature(Thermocouple)

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

KEK

19

Display of Control System

KEKB Review Committee/20070319

NAKAI Hirotaka

HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION

20

SummaryKEK

Crab cavity cryostats manufactured
successfully and connected to therefrigeration system
Calorimetric measurements carried outModerate heat load to cryostats
Cavity performance not so degraded
during installation to the cryostat

Monitoring devices equipped and work
properly
KEKB Review Committee/20070319

NAKAI Hirotaka