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 W@4.2K 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 W@4.2K 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