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Absorber R&D and Test Results
CM16 at RAL, Oct 8-11, 2006
Shoji Suzuki & Shigeru Ishimoto
KEK
1) Absorber Test Cryostat
2) Instrument and DAQ
3) H2 Cooling Test Results
4) He Cooling Test Results
5) 20 L Absorber Cooling Test Results
6) Summary
OUTLINE
Absorber Test Cryostat & Test Absorber
LH2/He Level Sensor
KF40 + 48 pin Feedthrough
KF40 L=100
Extension Tube
CX-1050-SDX5
(serial)
CX-1050-SDX1 calibrated
(4 wires)
2 cm
2 cm
2 cm
2 cm
1st stage
Heat Exchanger HEAT EXCHANGER ~60K
H2 or He GASINLET Cryocooler
Condenser
Mini-Flange Test
Mini Rotation Flange Mini-Flange
S-S
Aluminum
KF16
1mm dia. Indium
KF Flanges + Helicoflex
Condenser
48 Pin
Instrument and DAQ
LakeShore 218S
Keithley 2700 DMM
Cernox x8
MKS 0-2000 Torr
Level #1-5
VAC. Gauge . . .
MONITOR (LabView)
LakeShore 218 Keithley 2700 DMM
Absorber DAQ System
Wiring diagram of DAQ
Software front panel for data-logger
Software front panel for Cernox readout
Software front panel for data-logger
Cernox LH2 level indication
A part of software block diagram (data-logger)
A part of software block diagram (Cernox readout)
H2 Cooling Test
G-H2 was supplied to the Cryocooler from the 2 m3 tank at 1.3~1.0 atm.
L-H2; 0.368 l/h (w/o) 0.973 l/hr
(MICE 20 l ; 57 hr 22 hr )
Improvement by the Heat Exchanger
2,000 l Tank
-0.193 l/hr ~1.7 W
0.973 l/hr
~8.6 W
COOLING STOP
L-H2 Level Sensor Test
IN LIQUID(#2)
IN LIQUID(#1)
IN GAS(#5)
IN GAS(#4)
IN GAS(#3)
(#2)
(#1)
(#3)
(#4)
(#5)
48 PIN
L-H2 Level Sensor Test
RTH
L-H2 Level Sensor Test
RTH
LHe Cooling Test
G-He was supplied to the Cryocooler directly from a cylinder at 1.4 atm.
He ~3.7K
~ 0.6 atm
He ~4.6K
~ 1.4 atm
VAC; 10-7 ~10-8 Torr (No Leak)
LHe 4 K Leak Test
(Mini-Flanges and 48 Pin Feedthrough)
LHe Condensation and Evaporation Speed
ID=4cm
2cm
2cm
LHe 1.5 atm; 0.207 l/h (MICE 20 l ; 97 hr)
48 PIN
LHe Level Sensor Test
RTH
Calibrated Cernox vs. LHe Vapor Pressure
dT=10 mK
He Condensation
~ 4.6 K (1.4 atm)
Tmin~ 3.7 K (0.6 atm)
CX-1050SD-1.4D
Absorber Cooling Test 20 L Absorber was filled ~1.4 L L-H2.
20 l Absorber cooling test at KEK
(1) Assemble*Level sensors at bottom, 2 Cernox and 1 PtCo on body*Lead wires pass through at the LH2 condenser *window seal; d=1 mm Indium (1 loop)*8 G10 (t=5) supports*MLI set; Al-Mylar 9x5 + Nylon Mesh x6 1 layer on windows and G10 supports 4 layers on body ~2 layers on flexible pipes.
(2) Vacuum and Leak Test*Leak at 300K disassemble found pinhole at a Helicoflex KF25 changed recovered*vacuum; 3 x 10^(-6) Torr after 3 days, 300K
(3) Cooling Test #1 Sep-14, ‘06*cryocooler cooling 82 hrs; 300 20K *solid air blocking at the 1st stage heat exchanger
H2 impurity after 2 years operation for LH2 target
changed gas-H2 1.5 atm in the 2,000 L tank
(4) Cooling Test #2 (same assemble) Sep-22, ‘06*restart with LN2 pre-cooling
leak from N2 to vac. at ~200K stop LH2 filling*restart cryocooler w/o LN2 from 230K, takes 60 hrs from 230K to 20K*liquefied ~1.5 l H2 ( 1.5 0.9 atm 2,000 L tank)*measured H2 condensation and evaporation speed
20 l Absorber cooling test at KEK(continued)
Temperature sensors inside 20 l Absorber
Level (5 Cernoxes)
Cernox calibrated
Cernox abs.1Cernox abs.2
& PtCo
LH2 outlet
LN2(LHe) inlet
Level (5 Cernoxes)
5
4
3
2
1
Cernox calibrated
Attachment for Cernox abs.2 & PtCo
20 l Absorber assembled
LH2 inlet LH2 outlet
LN2(LHe) outlet
LN2(LHe) inlet
G10support
20 l Absorber MLI wrapped
MLI --- 1 layerAl-Mylar 9x5 + Nylon Mesh x6
Window 1 layer
Body 4 layers
CryocoolerTop flange
and warm bore
20 l Absorber inserted to warm boreand piping
LN2(LHe) outlet
LH2 inletLN2(LHe) inlet
LH2 outlet
Bottom view of H2
condenserLH2 supply LH2 return
LN2(LHe)return
LN2(LHe) supply
Kyocera 48 pin
From LH2 supply line (from Absorber)
To Bendix 18 pin
Insert toVacuum Chamber
Pipes withMLI ~2 layers
20 l Absorber H2 liquefaction test at KEK(LH2 1.425 l liquefied)
H2 Press. (Torr)
CX REF. 2nd.(ohm)
CX REF. 1st. (ohm)
CX0-calib. (K) *10
LH2 Temp_P. (K) *10
PtCo Abs. (K)*10
L-H2 in bodyL-H2 in pipe
20 l Absorber H2 liquefaction test at KEK
LH2
GH2
<Question>
Level sensors In LH2
at same time?
G10 support was turned down?
Cernox vs. H2-pressure
In LH2 Condenser
Temperature measurements by H2 pressure is possible
within error.
Cernox vs. H2-pressure
In Absorber
Temperature by H2 pressure
Liquefaction and Vaporization of LH2 in 20 l Absorber
0.30 l / h , 2.6 W 1.33 l / h , 11.7 W
2000 l tank
Cooling stopLH2 1.43 l
68 hrs to fill 20 l
(1) Cooling time (300K 20K)> 82 hrs by cryocooler only (not yet tested with LN2 pre-cooling)
Needs LN2 pre-cooling
(2) Condensation speed; 0.30 l / h , 2.6 W 68 hrs to fill 20L Needs better insulation to obtain shorter filling time
(3) Evaporation speed ~ heat leak; 1.33 l / h , 11.7 W (2)+(3) = 14.3 W ; net cooling power at absorber
LHe absorber required QL(heat leak) < 1.5 [email protected] LHe Absorber needs additional L-He supply ?
Summary 1/2(Absorber Cooling Test)
(1) Cooling test with LN2 pre-cooling> Cold leak test and fix the LN2 channel> Open the window and check the level sensors repair if it needs> Add PtCo thermometer on the dummy bore and in the
condenser
(2) Improvement of absorber insulation> design G-10 support, MLI ....
* Until QL < 1.5 [email protected] for the LHe absorber, if possible ? * Larger cooling power margin makes shorter filling time and easier operation for the LH2 absorber.
Summary 2/2(Future Plan)
Thank you