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Absorber R&D and Test Results. Shoji Suzuki & Shigeru Ishimoto KEK. CM16 at RAL, Oct 8-11, 2006. OUTLINE. Absorber Test Cryostat Instrument and DAQ H2 Cooling Test Results He Cooling Test Results 20 L Absorber Cooling Test Results Summary. Absorber Test Cryostat & Test Absorber.
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Absorber R&D and Test Results Shoji Suzuki&Shigeru Ishimoto KEK CM16 at RAL, Oct 8-11, 2006
OUTLINE • Absorber Test Cryostat • Instrument and DAQ • H2 Cooling Test Results • He Cooling Test Results • 20 L Absorber Cooling Test Results • Summary
LH2/He Level Sensor KF40 L=100 Extension Tube 2 cm CX-1050-SD X5 (serial) 2 cm 2 cm 2 cm CX-1050-SD X1 calibrated (4 wires) KF40 + 48 pin Feedthrough
H2 or He GAS INLET Cryocooler 1st stage Heat Exchanger HEAT EXCHANGER ~60K Condenser
Mini-Flange Test KF16 Condenser 1mm dia. Indium KF Flanges + Helicoflex S-S Mini-Flange Mini Rotation Flange Aluminum 48 Pin
Absorber DAQ System LakeShore 218S Cernox x8 Keithley 2700 DMM MKS 0-2000 Torr Level #1-5 VAC. Gauge . . . MONITOR (LabView) Keithley 2700 DMM LakeShore 218
Software front panel for data-logger Cernox LH2 level indication
H2 Cooling Test G-H2 was supplied to the Cryocooler from the 2 m3 tank at 1.3~1.0 atm.
Improvement by the Heat Exchanger L-H2; 0.368 l/h (w/o) 0.973 l/hr (MICE 20 l ; 57 hr 22 hr ) 0.973 l/hr ~8.6 W -0.193 l/hr ~1.7 W 2,000 l Tank COOLING STOP
L-H2 Level Sensor Test IN LIQUID(#2) IN GAS(#3) (#5) (#4) IN LIQUID(#1) (#3) IN GAS(#5) (#2) IN GAS(#4) (#1) 48 PIN
LHe Cooling Test G-He was supplied to the Cryocooler directly from a cylinder at 1.4 atm.
LHe 4 K Leak Test (Mini-Flanges and 48 Pin Feedthrough) He ~4.6K ~ 1.4 atm He ~3.7K ~ 0.6 atm VAC; 10-7 ~10-8 Torr (No Leak)
LHe Condensation and Evaporation Speed LHe 1.5 atm; 0.207 l/h (MICE 20 l ; 97 hr) 2cm 2cm 48 PIN ID=4cm
Calibrated Cernox vs. LHe Vapor Pressure CX-1050SD-1.4D Tmin~ 3.7 K (0.6 atm) dT=10 mK He Condensation ~ 4.6 K (1.4 atm)
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 9m x5 + 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
20 l Absorber cooling test at KEK (continued) (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
Temperature sensors inside 20 l Absorber Cernox abs.2& PtCo Cernox abs.1 LH2 outlet Level (5 Cernoxes) Cernox calibrated LN2(LHe) inlet
Level (5 Cernoxes) 5 4 3 2 1 Cernox calibrated
20 l Absorber assembled LH2 inlet LH2 outlet LN2(LHe) outlet LN2(LHe) inlet G10support
20 l Absorber MLI wrapped MLI --- 1 layer Al-Mylar 9m x5 + Nylon Mesh x6 Window 1 layer Body 4 layers
20 l Absorber inserted to warm boreand piping LH2 outlet LN2(LHe) outlet LH2 inlet LN2(LHe) inlet
From LH2 supply line (from Absorber) Bottom view of H2 condenser LH2 supply LH2 return LN2(LHe) supply LN2(LHe)return Kyocera 48 pin To Bendix 18 pin
Insert toVacuum Chamber Pipes with MLI ~2 layers
20 l Absorber H2 liquefaction test at KEK (LH2 1.425 l liquefied) H2 Press. (Torr) CX REF. 2nd.(ohm) PtCo Abs. (K)*10 CX0-calib. (K) *10 LH2 Temp_P. (K) *10 CX REF. 1st. (ohm) L-H2 in pipe L-H2 in body
20 l Absorber H2 liquefaction test at KEK GH2 <Question> Level sensors In LH2 at same time? G10 support was turned down? LH2
Temperature by H2 pressure Cernox vs. H2-pressure In LH2 Condenser Cernox vs. H2-pressure In Absorber Temperature measurements by H2 pressure is possible within error.
Liquefaction and Vaporization of LH2 in 20 l Absorber 2000 l tank 0.30 l / h , 2.6 W 1.33 l / h , 11.7 W 68 hrs to fill 20 l LH2 1.43 l Cooling stop
Summary 1/2 (Absorber Cooling Test) (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 W@4.2K LHe Absorber needs additional L-He supply ?
Summary 2/2 (Future Plan) (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 W@4.2K for the LHe absorber, if possible ? * Larger cooling power margin makes shorter filling time and easier operation for the LH2 absorber.