pacs instrument hardware design review cea-grenoble / dsm / drfmc / sbt / hso cryocoolers/ pacs...

PACS INSTRUMENT HARDWARE DESIGN REVIEW

CEA-Grenoble / DSM / DRFMC / SBT / HSO Cryocoolers/ PACS IHDR 1

MPE - November, 12-13 2003

HSO SORPTION COOLERS

Lionel DUBANDL. Clerc, D. Communal, M. Dubois (BV), JL. Durand, E. Ercolani, L. Guillemet, N. Luchier, L. Miquet, R. Vallcorba

Service des Basses TempératuresCEA-SBT

(CEA/DSM/DRFMC/SBT)




MODELS - GENERAL STATUS

Ref. Feature Objective Status

Structural Model

STMNo thermal capabilities

Validation of interfaces and Kevlar suspension system

Vibration tested room T and LN2 T

Delivered to SPIRE and PACS (Dec. 2002)

Cryogenic Qualification Model

CQM

Almost fully representatice of FM (thermo+heater not

of flight grade)

Qualify the design

• Qualification program carried out

• SPIRE unit delivered to RAL August 19th 2003 - back at SBT for retensioning

• PACS unit delivered to SAp Nov. 6th

Flight Model

FMFlight ready Successfull mission !

Detailed drawings available. Manufacturing phase initiated

Flight Spare

FSFlight ready

Replacement unit in case of FM failure




STRUCTURAL MODEL (STM)

• No thermal capabilities

• Main goal : validation of Kevlar suspension system

• Dummy cooler heart made out of aluminum(was not intended to bevibration tested cold)




VIBRATION TESTS - STM WITH KEVLAR 0.5 and 0.3 mmSinus [0 - 100 Hz]X : 40 GY, Z : 25 GRandom [0 - 2000 Hz]X : 14 G rmsY : 11.3 G rmsZ : 9.9 G rms Visual inspection :

rupture of one "stitch"

CS

L R

OO

M T

EM

PE

RA

TU

RE

TE

ST

S

KEVLAR FAILURE

Analysis :Lateralmotion

Rubbing& rupture

high Glevel

Solution at this stage

Kevlar 34Replaced by

Kevlar 11(Ø 0.29 mm to 0.5 mm)

• Stronger• easier to manipulate• Nominal tension x3

Note : lowest resonantfrequency > 450 Hz

All susbsequent tests successfully passed with larger Kevlar cords




Input spectrumRandom [0 - 2000 Hz]20 - 200 Hz : + 3 dB200 - 250 Hz : 0.28 g2/Hz250 - 2000 Hz : - 12 dB≈ 8.06 G rmsSinus [0 - 100 Hz] : 30 G

Both units mountedPACS like.Only X axis tested

SPIRE STM mounted with 0.29 mmKevlar strings on evaporator side

Lower levels

RA

L L

OW

TE

MP

ER

AT

UR

E T

ES

TS

VIBRATION TESTS - SUMMARY OF RESULTS

• Tests at room T : • Tests at 82 K : • Tests at room T Once units warm :

But∆ = 116 Hz

Low temperature : 82 K

NOTE : same signature after warm up at room T

Fre

qu

ency

sh

ift




FREQUENCY SHIFT ?Cold V test on STMs does not make sense- Structure = Ta6V (thermal contraction 1.5 10-3)

- Kevlar strings (-3 10-3, new value at -1.7 10-3 since then)

- Aluminum body for cooler heart (4 10-3)

Internal strings ≈ 13.9 DaN

External strings ≈ 2.9 DaN

Tensioning at room T12 DaN

At low T




fx,y =12π

8AY(b2+r2)ml3

fz =12π

16AYa2

ml3

tension dependent ?

VARIATION OF RESONANT FREQUENCIES WITH TEMPERATURE

0

5

10

15

20

25

0 1 2 3 4 51 - tensioning (RT)1 - detensioning (RT)2 - tensioning (RT)2 - detensioning (RT)3 - tensioning (RT)3 - detensioning (RT)

Tension (DaN)

∆l (mm)

Kevlar 11 (0.5 mm)length : 155 mm

define a "dynamic" Young’s modulus in real situation

Y300K = 38.7 TE-0.018 + 3.4 TE0.516 (GPa)

Assuming average fit for up and down(TE : tension in N)

Hysteresis betweentensioning - detensioning

Real situation : string + pulleys400

450

500

550

600

0 50 100 150

Resonant frequency (Hz)Calculated frequency

Resonant frequency (Hz)

Tension (N)




CRYOGENIC QUALIFICATION MODEL (CQM)

Both CQMs qualified

SPIRE : 290µm/500 µm stringsPACS : all strings 500 µm




QUALIFICATION PROGRAM

5 days80°C bake out

Room Tvibration tests

Thermal testsNominal perf.

Thermal tests(HCR#2)






EXPERIMENTAL SET-UP




0

10

20

30

40

50

0

1

2

3

4

5

0 50 100 150

Sorption pump

Heat switch pump

Heat switch evaporator

Evaporator

Thermal shunt

Cryostat cold plate (Level 0)

Titanium frame (Level 1)

Temperature (K)Temperature (K)

Time (mn)

right scale

left scale

PACS CQM Unit - June 2003HCR# 2 - Second recyclingHSE ≈ 21 K (1.4 mA)300 mW input power to sorption pumpCryostat tilted to 60 degre

RECYCLING PHASE - CRYOSTAT TILTED AT 60°




HEAT FLOWS - CRYOSTAT TILTED AT 60°

0

10

20

30

40

50

60

70

80

0

200

400

600

800

1000

0 20 40 60 80 100 120

Heat flow at evaporator switch interface (mW)Heat flow at pump switch interface (mW)

Time (mn)

CQM PACSThermal tests June 2003 - HCR #2Level 1 (titanium frame) ≈ 2 KLevel 0 (cryostat cold plate) : 1.62 KSecond recycling

Right scale

Left scale

Integrals give :evaporator switch interface* : 205 Jpump switch interface : 340 J(*: longer condensation to try to reduce the heat flowat the end of the condensation phase)

14 mW heat flow

Cryostat tilted at 60 degreeduring condensation

Note : use of the full 120 mn for the recycling phase, to get a flowing power as low as possible at the end of the phase




CONVECTIVE EFFECTS - CRYOSTAT TILTING

0

20

40

60

80

0

100

200

300

400

500

600

700

0 50 100 150

Heat flow at evaporator switch interface (mW)Heat flow at pump switch interface (mW)

Time (mn)

CQM SPIREThermal tests June 2003 - HCR #1Level 1 (titanium frame) ≈ 2.1 KLevel 0 (cryostat cold plate) : 1.65 K

Right scale

Left scale

Integrals give :evaporator switch interface : not relevant (test on orientation)pump switch interface : 344 J (similar PACS = 340)

cryostat at 30 degree angleis further tilted to 60

27 mW heat flow

19 mW heat flow

18 mW heat flow

further tilted to 90

Possibly down to 14 mW




VIBRATION TESTS - CSL JULY 2-4 2003

Inp

ut

leve

ls

X Y Z

SPIRE Sinus[25 - 60]

22.5 G

[25 - 60]

15 G

[25 - 60]

15 G

Random [20 - 2000]

5 Grms 6 Grms 6 Grms

PACS Sinus[5 - 100]

18 G

[5 - 100]

8 G

[5 - 100]

8 G

Random [20 - 2000]

11.5 Grms 4.9 Grms 2.54 Grms




CSL CQM VTESTS (RT) - INSTRUMENTATION

Accelerometers :- two pilotes on adaptating plate- structure- evaporator cold tip- evaporator switch base- pump switch base




MAIN RESULTS

No major failure (lost one wire on HS redunded - CQM PACS)

Cold tip StructureHS evap.

I/FHS pump

I/F

XSPIRE 386 / 15 826 / 3.7138 / 1.9

339 / 19.5

138 / 1.7

368 / 9

YSPIRE 561 / 23.3 1360 / 1.36 705 / 14.8 705 / 17

ZSPIRE

291 / 2.6

397 / 11.7

1130 / 1.8

1580 / 5.8

127 / 1.7

293 / 17.2

136 / 2.8

295 / 12.1

XPACS 558 / 211230 / 3.9

1580 / 5.5

126 / 1.6

337 / 17

132 / 1.8

360 / 14.6

YPACS 653 / 211180 / 3.5

1380 / 3.8

302 / 2.8

653 / 14.5

325 / 4.3

761 / 13

ZPACS

460 / 2.7

532 / 25.6

923 / 6.3

1010 / 5.6

128 / 2.1

305 / 7

134 / 2.6

320 / 7

XX / YY :XX : resonant frequencyYY : corresponding G(0.5 G excitation)

[800 - 1500 Hz]

[300 - 650 Hz]

[300 - 360 Hz]

[125 - 140 Hz]




COOLING POWER CURVES - HEALTH CHECK REPORT

250

300

350

0 20 40 60 80 100

HCR#1 - horizontalHCR#1 - right side upHCR#1 - upside downHCR#2 - horizontalHCR#2 - right side upHCR#2 - upside downHCR#3 - horizontalHCR#3 - right side upHCR#3 - upside down

Temperature (mK)

Cooling power (µW)

CQM SPIRE - Thermal tests June - July 2003 Comparison HCR #1 HCR#2 and HCR#3Level 1 (titanium frame) : 2 KLevel 0 (cryostat cold plate) : ≈ 1.6 K

250

300

350

0 20 40 60 80 100

HCR#1 - horizontalHCR#1 - right side upHCR#1 - upside downHCR#2 - horizontalHCR#2 - right side upHCR#2 - upside downHCR#3 - horizontalHCR#3 - right side upHCR#3 - upside down

Temperature (mK)

Cooling power (µW)

CQM PACS - Thermal tests June - August 2003 Comparison HCR #1 HCR#2 and HCR#3Level 1 (titanium frame) : 2 KLevel 0 (cryostat cold plate) : ≈ 1.6 K

Note : HCR#3/upside downLevel 0 at1.66 K

HCR#1 - CQM PACS :Parasitics estimated at 12 µW ± 10% [Case 1.62 K level 0 - 2 K level 1]Prediction ≈ 10 µW

No significant difference between HCR#1, HCR#2 and HCR#3or rather results consistent within ± 5 mK




AUTONOMY TESTSNominal conditions : L0 = 1.7 K - L1 = 4 K• First test with 10 µW applied load

CQM SPIRE 45 hours @ 290 mK

CQM PACS 35 hours @ 291 mK

m0.L = (Papplied + Pparasitics).time

m0: amount condensed / L: latent heat

1/time versus Papplied

Straight line :m0 and parasitics

• tests with various applied loads

Not within predictions

Tests performed in same conditions every time




AUTONOMY TESTS - MORE DATA

0 5 10-5 0,0001 0,00015 0,0002 0,00025

1 10-5

2 10-5

3 10-5

4 10-5

5 10-5

6 10-5

y = 5,3392e-06 + 0,22163x R= 0,99898

Applied load (W)

Theoretical curve

CQM PACS - Autonomy tests Nominal conditions - L0 = 1.7 K / L1 = 4 K

1/time (s

-1)

0

1 10-5

2 10-5

3 10-5

4 10-5

5 10-5

6 10-5

0 50 100 150 200 250

y = 4,11371e-06 + 2,09004e-07x R= 1

1/time (s

-1)

Applied load (µW)

CQM SPIRE - Autonomy tests Nominal conditions - L0 = 1.7 K / L1 = 4 K

Theoretical curve

Analysis of data• Extra parasitic of 8 to 10 µW

• Cooler undercharged by 10%




EXTRA PARASITIC LOAD ANALYSIS - KEVLAR ?

0

5

10

15

20

25

30

35

40

0 2 4 6 8 10

Extracted from evaporator slopeExtracted from sorption pump (heat of adsorption)Theoretical value

Additionnal load from Kevlar (µW)

T structure (K)

CQM PACS - Kevlar thermal load testsL0 average = 1.6 K

Point at 1.916 is taken as the reference.Additionnal load is determinedfrom this point on

OK at least in the range [2 K - 10 K]

Remark : results eliminate possibility of parasitic coming from contact with snubber




EXTRA PARASITIC LOAD ANALYSIS - KEVLAR & TITANIUM

From experimental data : 6.5 µW

Predicted : 6.7 µW

0 2 10-5 4 10-5 6 10-5 8 10-5 0,0001

Experimental dataPredicted (4He case)Predicted (3He case)5 10-6

1 10-5

1,5 10-5

2 10-5

2,5 10-5

y = 1,785e-06 + 0,27397x R= 0,99931

Applied load (W)

Theoretical curve

CQM PACS - Autonomy tests Conditions - L0 = 1.57 K / L1 = 2 K

1/time (s

-1)

0 2 10-5 4 10-5 6 10-5 8 10-5 0,0001

Experimental dataPredicted (4He case)Predicted (3He case)4 10-6

8 10-6

1,2 10-5

1,6 10-5

2 10-5

2,4 10-5

Applied load (W)

Theoretical curve

CQM PACS - Autonomy tests Conditions - L0 = 1.57 K / L1 = 2 KCooler undercharged by 12%

1/time (s

-1)

Cooler operated without strap between switch and evaporator

Parasitic load

Note :cycle limited to 2.2 K / 35 K




EXTRA PARASITIC : GAS GAP HEAT SWITCH + STRAP

250

300

350

400

0 20 40 60 80 100

HCR#1 - horizontalHCR#1 - right side upHCR#1 - upside downHCR#2 - horizontalHCR#2 - right side upHCR#2 - upside downHCR#3 - horizontalHCR#3 - right side upHCR#3 - upside downStrap problem ?HCR#3bis - horizontal after strap fixingHCR#3bis - right side up after strap fixingHCR#3bis - upside down after strap fixing

Temperature (mK)

Cooling power (µW)

CQM PACS - Thermal tests June - September 2003 Comparison HCR #1 HCR#2, HCR#3and HCR after strap fixing

Level 1 (titanium frame) : 2 KLevel 0 (cryostat cold plate) : ≈ 1.6 K

Note : HCR#3/upside downLevel 0 at1.66 K

Degraded performancewith "stressed" strap




LATEST RESULTS - CQM Reset to nominal (strap not gold plated)

0 5 10-5 0,0001 0,00015 0,0002 0,00025

Previous testLast test (new strap)Theory

1 10 -5

2 10 -5

3 10 -5

4 10 -5

5 10 -5

6 10 -5

y = 5,3392e-06 + 0,22163x R= 0,99898

y = 3,0413e-06 + 0,2358x R= 0,99951

Applied load (W)

Theoretical curve

CQM PACS - Autonomy tests Nominal conditions - L0 = 1.7 K / L1 = 4 K

1/time (s

-1)

CQM PACS delivered to SAp November 6th

Nominal conditions : L0 = 1.7 K - L1 = 4 K

With 10 µW applied load

47 hours @ 291 mK

Analysis of data

• Parasitic of 13 µW (predicted 14 µW)




Heat switch - FM/FS models- production of a batch (≈ 10)- selection of best ones for cold tip- thermal characterisation procedure revisited- improved strap

FUTURE ACTIONS

- geometry ?- limit the heat flow in case of contact ?- strap : flexibility

ON going thinking




YOUNG’S MODULUS VERSUS TENSION : IMPACT ON COOLER

0

100

200

300

400

500

600

700

0

50

100

150

0 20 40 60 80 100 120 140 160

Resonant frequency (Hz) Tension at low T (N)

Tension at room temperature (N)

Simulation on pump sidesuspended mass : 178 gramsKevlar thermal expansion :

Abakians's measurement (-1.7 10 -3)

tension RT=

tension LT

Tension at low T

Room temperatureresonant frequency

Low temperature resonant frequency

Sliding ?




KEVLAR TENSION HISTORY

Note : CQM PACS not retensioned at delivery (SAp demand)

0

50

100

150

0 50 100 150 200 250

SPIRE and PACS CQM Coolers qualification programKevlar tension history

PACS CQM - string #1 from capstan (1/8)

PACS CQM - string #6 from capstan (6/8)

PACS CQM -average tension (1/8, 6/8)

SPIRE CQM - string #1 from capstan (1/8)

SPIRE CQM - string #6 from capstan (6/8)

SPIRE CQM -average tension (1/8, 6/8)

Tension (N)

Number of days

A : HCR #1B : 5 days bake out (80 C)C : HCR #2D : Vibration testsE : HCR #3F : last measurement prior to delivery

SiT : sitting in clean roomTR : transport + SiTReT : Retensioning

BReT

A

Sit C

TRD

EF

after Vtest on Y axis

At SBTafter Vtest

B

C

Sit + 4 T test

ReT Sit

Sit

TR

after Vteston X axis

At SBTafter Vtest

D

Sit F

CQM returned to SBT(for replacement of strings following new tensioning procedure)

4 hours 80°C bake out

4 hours 80°C bake out

pacs instrument hardware design review cea-grenoble / dsm / drfmc / sbt / hso cryocoolers/ pacs...

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