development of milli-kelvin adr technology for space missions

354 Pages·2012·4.89 MB·English

by  Shane Akbar Weatherstone

_____________________________________________________________________
D M -K ADR
EVELOPMENT OF ILLI ELVIN

TECHNOLOGY FOR SPACE MISSIONS
______________________________

SHANE AKBAR WEATHERSTONE

MULLARD SPACE SCIENCE LABORATORY
DEPARTMENT OF SPACE AND CLIMATE PHYSICS
UNIVERSITY COLLEGE LONDON

A THESIS SUBMITTED TO UNIVERSITY COLLEGE LONDON (UCL)
FOR THE DEGREE OF DOCTOR OF PHILOSOPHY

JANUARY 2012
_____________________________________________________________________
P age | 2

D
ECLARATION

I, Shane Akbar Weatherstone, hereby confirm that the work presented in this thesis is
my own. Where information has been derived from other sources, I confirm that this has
been indicated in the thesis.
P age | 3

A
BSTRACT

Cryogenics is increasingly required for space applications as new detector technologies
emerge offering improved performance, as is exemplified by future X-ray astronomy
missions.
The IXO1 (International X-ray Observatory) mission will carry an X-ray Microcalorimeter
Spectrometer (XMS), requiring a 50mK operating temperature. Two space-
demonstrated technologies are capable of maintaining milli--Kelvin temperatures:
Adiabatic Demagnetisation Refrigerators (ADRs) and open-cycle Dilution refrigerators.
ADRs are simpler, more reliable, and have a longer lifetime than open-cycle dilution
refrigerators which deplete their Helium stores after ~3 years. For long-life (>5 year)
missions, ADRs are the best practical choice.
MSSL have built an engineering model ADR for the XEUS (X-ray Evolving Universe
Spectroscopy) mission. However, the ADR cannot achieve the required hold time and
recycle time. This thesis shows how a magnetoresistive heat switch can improve
performance such that the required hold time can be achieved.
Tungsten Magnetoresistive heat switch technology is developed through experimental
investigation. Heat switch performance is found to be a function of purity; the difference
between an otherwise identical 99.992% and a 99.999% pure sample is very significant,
with switching ratios of 437 and 1×104 respectively at ~4K. The ‘on’ state thermal

1 NOTE: During the writing of this thesis, the IXO mission ceased to be a candidate of the
L-class missions under consideration by ESA. However, due to the strong science case of
IXO; ESA, Astrium and the scientific community are investigating to what extent a
European-led mission could preserve the original science goals of IXO. This new study is
ATHENA (Advanced Telescope for High ENergy Astrophysics).
P age | 4

conductivity is limited by sample size as it is reduced to the electron mean free path and
below. A Tungsten magnetoresistive heat switch mounted in the XEUS ADR via bolted
joints lined with 0.13mm thick Indium foil can improve its performance to meet the
design requirements.
MSSL are developing an ADR targeting the IXO XMS. The cooling chain required to
support the ADR is presented. The design feasibility and compliance to requirements are
verified by thermal and mechanical analyses, and it is shown that the ADR can be
supported during holding and recycling for both warm and cold redundancy modes of
higher temperature stage coolers in the chain.
P age | 5

C
ONTENTS
DECLARATION ............................................................................................................................. 2
ABSTRACT ................................................................................................................................... 3
CONTENTS ................................................................................................................................... 5
LIST OF FIGURES ........................................................................................................................ 10
LIST OF TABLES .......................................................................................................................... 16
LIST OF ABBREVIATIONS ........................................................................................................... 18
ACKNOWLEDGEMENTS ............................................................................................................. 21
OVERVIEW OF THESIS................................................................................................................ 22
CHAPTER 1: ............................................................................................................................... 26
X-RAY ASTRONOMY .................................................................................................................. 26
1.1 Introduction to X-Ray Astronomy................................................................................................ 27
1.1.1 Introduction ............................................................................................................................. 27
1.1.2 X-Ray Processes ........................................................................................................................ 28
1.1.3 A Short History of X-Ray Astronomy ........................................................................................ 30
1.2 IXO - International X-ray Observatory ......................................................................................... 34
1.2.1 Mission Overview ..................................................................................................................... 34
1.2.2 Instrument Overview ............................................................................................................... 35
1.3 XMS – X-ray Microcalorimeter Spectrometer ............................................................................. 39
1.3.1 IXO XMS Science Goals ............................................................................................................. 40
1.3.1.1 Co-Evolution of Galaxies and Their Super Massive Black Holes (SMBH) ........................ 41
Obscured Growth of SMBH ............................................................................................................... 41
Cosmic feedback from SMBH ............................................................................................................ 42
1.3.1.2 Large Scale Structure and The Creation of Chemical ELements ..................................... 43
1.3.1.3 Matter Under Extreme Conditions ................................................................................ 45
1.3.2 Principles of Microcalorimetry ................................................................................................. 48
1.3.3 Transition Edge Sensors ........................................................................................................... 49
1.3.4 IXO XMS Instrument ................................................................................................................. 51
1.4 Summary ..................................................................................................................................... 54
CHAPTER 2: ............................................................................................................................... 55
SPACE CRYOGENICS................................................................................................................... 55
2.1 Cryogenics and Space Cryogenics................................................................................................ 56
2.1.1 Introduction to Cryogenics ....................................................................................................... 56
2.1.2 Introduction to Space Cryogenics............................................................................................. 58
2.1.3 The Thermal Environment of Space ......................................................................................... 59
2.1.4 Considerations For Space Cryogenics ....................................................................................... 63
2.2 Cryogenic cooling - Temperatures > 1K ....................................................................................... 68
2.2.1 Cryogens ................................................................................................................................... 68
2.2.1.1 Cryogenic Helium ........................................................................................................... 70
2.2.2 Cryogen use in Space................................................................................................................ 73
2.2.3 CryoCoolers .............................................................................................................................. 74
2.2.3.1 The Carnot Cooling Cycle ............................................................................................... 75
2.2.3.2 Stirling Coolers ............................................................................................................... 78
P age | 6

2.2.3.3 Gifford McMahon Coolers ............................................................................................. 82
2.2.3.4 Pulse Tube Coolers ......................................................................................................... 83
2.2.3.5 Joule Thomson Coolers .................................................................................................. 86
2.2.4 Passive Cooling ......................................................................................................................... 90
2.2.4.1 Radiators ........................................................................................................................ 90
2.3 Cryogenic cooling - Temperatures <1K ........................................................................................ 93
2.3.1 Sorption Coolers ....................................................................................................................... 93
2.3.2 Dilution Coolers ........................................................................................................................ 95
2.3.3 Magnetic Coolers ..................................................................................................................... 98
2.4 Chapter summary ...................................................................................................................... 100
CHAPTER 3: ............................................................................................................................. 103
ADIABATIC DEMAGNETISATION REFRIGERATORS ................................................................... 103
3.1 Introduction to ADRs ................................................................................................................. 104
3.1.1 Introduction to Magnetic cooling ........................................................................................... 104
3.1.2 Principle of Magnetic Cooling ................................................................................................ 105
3.1.3 Magnetic Cooling Cycle .......................................................................................................... 108
3.1.4 ADRs ....................................................................................................................................... 110
3.1.5 Salt Pill .................................................................................................................................... 111
3.1.5.1 Paramagnetic Materials ............................................................................................... 111
3.1.6 Heat Switches ......................................................................................................................... 115
3.1.6.1 Mechanical Heat Switches ........................................................................................... 115
3.1.6.2 Superconducting Heat Switches .................................................................................. 116
3.1.6.3 Gas-Gap Heat Switches ................................................................................................ 117
3.1.6.4 Magnetoresistive Heat Switches .................................................................................. 119
3.2 ADR Systems.............................................................................................................................. 120
3.2.1 General Types of ADR ............................................................................................................. 120
3.2.1.1 Single ADR .................................................................................................................... 120
3.2.1.2 Double ADR .................................................................................................................. 121
3.2.1.3 Continuous ADR ........................................................................................................... 123
3.2.2 MSSL ESA ADR ........................................................................................................................ 125
3.2.2.1 General Overview ........................................................................................................ 126
3.2.2.2 Performance ................................................................................................................ 127
3.2.3 ADRs in Space ......................................................................................................................... 130
3.3 ADR Solutions for IXO ................................................................................................................ 132
3.3.1 MSSL dADR ............................................................................................................................. 132
3.3.2 CEA-SBT Hybrid Sorption Cooler/ADR .................................................................................... 135
3.3.3 JAXA ADR ................................................................................................................................ 137
3.3.4 NASA CADR ............................................................................................................................. 138
3.4 Chapter Summary ..................................................................................................................... 140
CHAPTER 4: ............................................................................................................................. 141
METALS AND MAGNETORESISTANCE ...................................................................................... 141
4.1 Thermal conductivity of Metals ................................................................................................ 142
4.1.1 Lattice Thermal Conductivity.................................................................................................. 142
4.1.2 Electron Thermal Conductivity ............................................................................................... 150
4.1.3 Relative Contributions to the Total Thermal Conductivity ..................................................... 161
4.2 Magnetoresistance .................................................................................................................... 164
4.2.1 Magnetoresistive metals ........................................................................................................ 166
4.2.2 Tungsten ................................................................................................................................. 172
4.2.3 Tungsten as a Magnetoresistive heat switch for Space Cryogenics ....................................... 174
4.3 Summary of Chapter 4 .............................................................................................................. 176
CHAPTER 5: ............................................................................................................................. 177
P age | 7

DEVELOPMENT OF A TUNGSTEN MAGNETORESISTIVE HEAT SWITCH. .................................... 177
5.1 Introduction .............................................................................................................................. 178
5.2 Thermal conductivity measurements ........................................................................................ 180
5.2.1 Experimental Method ............................................................................................................ 180
5.2.1.1 Investigated Tungsten Samples ................................................................................... 180
5.2.1.2 ‘Off’ State Thermal Conductivity Measurement Method ............................................ 184
5.2.1.3 ‘On’ State Thermal Conductivity Measurement Method ............................................. 187
5.2.1.4 Extraction Of Thermal Conductivity Data From Measurements .................................. 188
5.2.2 Results .................................................................................................................................... 189
5.2.2.1 ‘Off’ State Thermal Conductivity .................................................................................. 189
5.2.2.2 ‘On’ State Thermal Conductivity .................................................................................. 191
5.2.2.3 Switching Ratio ............................................................................................................ 192
5.2.3 Analysis and Discussion of Results ......................................................................................... 194
5.2.3.1 Estimation of – A Measure of Magnetoresistive Effect ....................................... 194
5.2.3.2 High Field Magnetoresistance Theoretical Description of Results ............................... 197
5.2.3.3 Non High Field Samples ............................................................................................... 206
5.2.3.4 Interpretation of High Field Magnetoresistive Description of Sample 1 ...................... 208
5.2.4 Comparison of Measured Data to Published Results ............................................................. 210
5.2.4.1 Interpretation of Findings ............................................................................................ 215
5.2.5 Summary Of Findings ............................................................................................................. 222
5.3 Interfacing to the Tungsten Heat Switch ................................................................................... 224
5.3.1 Experimental methods ........................................................................................................... 227
5.3.2 Results and Analysis ............................................................................................................... 229
5.4 Effects on ESA ADR Performance .............................................................................................. 235
5.5 Summary of Chapter 5 .............................................................................................................. 242
CHAPTER 6: ............................................................................................................................. 244
IXO COOLING CHAIN SOLUTION DEVELOPMENT ..................................................................... 244
6.1 Requirements of the IXO Cryogenic Cooling System ................................................................. 245
6.1.1 Overview of dADR Requirements ........................................................................................... 245
6.1.2 System Level Requirements ................................................................................................... 246
6.1.2.1 dADR Heat Bath ........................................................................................................... 246
6.1.2.2 Accommodation ........................................................................................................... 246
6.1.2.3 Harness and Current leads ........................................................................................... 247
6.1.3 The Need for a Cooling Chain ................................................................................................. 247
6.2 Available Cooling Chain Technology .......................................................................................... 249
6.2.1 Introduction ........................................................................................................................... 249
6.2.2 Radiators ................................................................................................................................ 249
6.2.3 Astrium Stirling Coolers ......................................................................................................... 250
6.2.4 Cryogen-Free dADR Heat Bath ............................................................................................... 250
6.3 Overview of Proposed IXO Cooling Chain ................................................................................. 252
6.3.1 Introduction ........................................................................................................................... 252
6.3.2 Cooler Selection Philosophy ................................................................................................... 252
6.3.3 Design Basis ............................................................................................................................ 253
6.3.4 Proposed Cooling Chain ......................................................................................................... 253
6.3.4.1 102K Stage ................................................................................................................... 254
6.3.4.2 80K Stage ..................................................................................................................... 256
6.3.4.3 16K Stage ..................................................................................................................... 257
6.3.4.4 2K Stage ....................................................................................................................... 257
6.3.5 Redundancy ............................................................................................................................ 258
6.3.5.1 Redundancy modes ..................................................................................................... 258
6.3.5.2 Conduction Through Inactive Coolers .......................................................................... 259
6.3.6 Cryostat Location on Spacecraft ............................................................................................. 259
6.4 Proposed Design........................................................................................................................ 261
P age | 8

6.4.1 Overview ................................................................................................................................ 261
6.4.2 CVV Sizing Philosophy ............................................................................................................ 261
6.4.3 Components of CVV Assembly ............................................................................................... 262
6.4.4 Design of CVV ......................................................................................................................... 264
6.4.5 Temperature Stage Accommodation ..................................................................................... 266
6.4.6 Accommodation of Stirling Cooler Displacers ........................................................................ 267
6.4.7 Thermal Shields ...................................................................................................................... 268
6.4.7.1 Overview ...................................................................................................................... 268
6.4.7.2 MLI ............................................................................................................................... 268
6.4.7.3 Radiative Heat Transfer Between Sheilds .................................................................... 270
6.4.7.4 Shield Properties .......................................................................................................... 272
6.4.8 Electrical Interfacing ............................................................................................................... 274
6.4.8.1 ADR Current Leads ....................................................................................................... 274
(a) Heat Conduction .................................................................................................................... 274
(b) Joule Heating ......................................................................................................................... 274
6.4.8.2 Optimised Current Leads ............................................................................................. 275
6.4.8.3 Harness ........................................................................................................................ 276
6.5 CVV Suspension System Design ................................................................................................. 277
6.5.1 Simple Mechanical Analysis For Suspension Design ............................................................... 277
6.5.2 Suspension Design Philosophy ............................................................................................... 281
6.5.3 Suspension Stiffness Analysis ................................................................................................. 285
6.5.3.1 Overview ...................................................................................................................... 285
6.5.3.2 Suspension Stage Spring Constant ............................................................................... 285
6.5.3.3 Tube Stiffness .............................................................................................................. 286
6.5.3.4 Strap Stiffness .............................................................................................................. 286
6.5.4 Thermal Conduction Through the Suspension System ........................................................... 287
6.5.4.1 Overview ...................................................................................................................... 287
6.5.4.2 Heat conducted through Tubes ................................................................................... 288
6.5.4.3 Conduction through Straps .......................................................................................... 289
6.5.5 Proposed Suspension System Configuration .......................................................................... 289
6.5.5.1 - 16K-2K Suspension..................................................................................................... 289
6.5.5.2 - 80K-16K Suspension................................................................................................... 291
6.5.5.3 - 300K-80K Suspension................................................................................................. 295
6.5.6 Suspension Tensioning System............................................................................................... 296
6.5.7 Suspension Modes ................................................................................................................. 299
6.6 80K Radiator TLA Feedthrough ................................................................................................. 300
6.6.1 Overview ................................................................................................................................ 300
6.6.2 Design Concept ...................................................................................................................... 301
6.6.3 Thermal Model of Feedthrough Assembly ............................................................................. 302
6.6.4 Conductive Heat Transfer ....................................................................................................... 305
6.6.5 Radiative Heat Transfer .......................................................................................................... 305
6.6.6 Total Heat Through Each Cylinder .......................................................................................... 307
6.6.7 Results Of Thermal Modelling Investigation .......................................................................... 308
6.6.7.1 Number of Cylinders .................................................................................................... 308
6.6.7.2 Cylinder Height ............................................................................................................ 310
6.6.7.3 Feedthrough Outer Radius ........................................................................................... 311
6.6.8 Design Implications ................................................................................................................ 313
6.6.9 Optimal Design ....................................................................................................................... 315
6.8 Cooling Chain Thermal Analysis ................................................................................................ 319
6.8.1 Overview ................................................................................................................................ 319
6.8.2 dADR Holding ......................................................................................................................... 320
6.8.2.1 Warm Redundancy Mode ............................................................................................ 320
6.8.2.2 Cold Redundancy Mode ............................................................................................... 321
6.8.3 dADR Recycling ....................................................................................................................... 323
6.8.3.1 Warm Redundancy Mode ............................................................................................ 323
P age | 9

6.8.3.2 Cold Redundancy Mode ............................................................................................... 325
6.8.4 Summary ................................................................................................................................ 327
6.9 Chapter Summary ..................................................................................................................... 329
CHAPTER 7: ............................................................................................................................. 331
SUMMARY & FURTHER DEVELOPMENT .................................................................................. 331
7.1 Summary of Thesis .................................................................................................................... 332
7.1.1 Chapter 1 ................................................................................................................................ 332
7.1.2 Chapter 2 ................................................................................................................................ 333
7.1.3 Chapter 3 ................................................................................................................................ 334
7.1.4 Chapter 4 ................................................................................................................................ 336
7.1.5 Chapter 5 ................................................................................................................................ 337
7.1.6 Chapter 6 ................................................................................................................................ 340
7.2 Further Developments - Magnetoresistive Heat Switch .......................................................... 342
7.2.1 Heat Switch Performance Research ....................................................................................... 342
7.2.2 Working towards a Space Qualified Magnetoresistive Heat Switch ...................................... 343
7.3 Further Developments – IXO Cooling Chain .............................................................................. 344
7.4 Summary of Chapter 7 .............................................................................................................. 345
REFERENCES ............................................................................................................................ 347
P age | 10

L F
IST OF IGURES
FIGURE 1: THE SENSITIVITY (IN ERGS, WHERE 1 ERG = 10-7 J = 6.24×1011 EV) ACHIEVED WITH VARIOUS PREVIOUS X-
RAY MISSIONS. SINCE THE ORIGINAL PUBLICATION OF THIS FIGURE (2) (2000) THE QUESTION MARK HAS BEEN
REPLACED BY SUZAKU LAUNCHED IN 2005, AND AXAF WAS RENAMED CHANDRA. ADAPTED FROM (2). ...... 32
FIGURE 2: COMPARISON OF KEY PERFORMANCE PARAMETERS BETWEEN IXO AND THE CONTEMPORARY LEADING
MISSIONS. AFTER (7).................................................................................................................... 35
FIGURE 3: OBSERVATIONAL EFFICIENCY WITH HXI AND WFI INSTRUMENTS. AFTER (7). ..................................... 37
FIGURE 4: LEFT: IXO HIGH-RESOLUTION X-RAY SPECTRA (BLUE) SHOW THE METAL-ENRICHED HOT GAS OUTFLOWING
FROM STARBURST GALAXY MESSIER 82, A PART OF THE FEEDBACK PROCESS UNRESOLVABLE WITH CURRENT X-
RAY CCD DATA (MAGENTA). THE INSERT SHOWS THAT THE HE-LIKE EMISSION LINE TRIPLET OF NEIX CAN BE
RESOLVED, AND THAT NOT ONLY VELOCITIES CAN BE MEASURED, BUT THE PLASMA TEMPERATURE AND
IONISATION STATE CAN BE DIAGNOSED. RIGHT: SUPERWINDS IN MESSIER 82, EXHIBITING A STARBURST-DRIVEN
SUPERWIND. DIFFUSE THERMAL X-RAY EMISSION AS SEEN BY CHANDRA IS SHOWN IN BLUE. HYDROCARBON
EMISSION AT 8µM FROM NASAS SPITZER TELESCOPE IS SHOWN IN RED. OPTICAL STARLIGHT (CYAN) AND
HΑ+[NII] (YELLOW) ARE FROM HST-ACS (ADVANCED CAMERA FOR SURVEYS ON THE HUBBLE SPACE
TELESCOPE) OBSERVATIONS. FIGURE AND CAPTION AFTER (7). ............................................................. 39
FIGURE 5: IXO SPECTRUM OF FE XXV LINES SHOWS THAT TURBULENCE OF ~150 KM/S OR ~200 KM/S MAY BE
DISTINGUISHED FROM THERMAL BROADENING ALONE. THIS CANNOT BE DONE AT CCD RESOLUTION.
SIMULATED IXO XMS DATA IN BLACK, MODELS IN COLOUR. AFTER (7). ................................................. 44
FIGURE 6: LEFT: X-RAY ILLUMINATION OF THE INNER ACCRETION DISK PROVIDES A UNIQUE PROBE OF THE STRONG
GRAVITY ENVIRONMENT NEAR BLACK HOLES. IF THE BLACK HOLE IS SPINNING THE DISK EXTENDS CLOSER TO THE
EVENT HORIZON, RESULTING IN A MUCH BROADER, REDSHIFTED LINE PROFILE. RIGHT: SIMULATED IXO-XMS
SPECTRUM OF A BRIGHT AGN, SHOWING VARIOUS BROAD FE EMISSION LINE PROFILES FOR DIFFERENT SMBH
SPINS (WITH AN EQUIVALENT WIDTH OF 330 EV), SUPERPOSED ON THE NARROW EMISSION AND ABSORPTION
FEATURES (TYPICALLY OF < 10 EV) RESULTING FROM MORE DISTANT MATERIAL. THIS SHOWS THAT THE XMS
WILL BE ABLE TO SEPARATE THE NARROW FEATURES FROM THOSE PRODUCED BY STRONG GRAVITY. AFTER (7).
................................................................................................................................................ 46
FIGURE 7: MASS-RADIUS RELATION FOR TYPICAL EQUATIONS OF STATE ALONGSIDE CONSTRAINTS. THE RED DASHED
CURVE IS THE CORRECT EQUATION OF STATE IN THIS CASE. AFTER (7). .................................................... 47
FIGURE 8: SCHEMATIC REPRESENTATION OF A MICROCALORIMETER. AFTER (7). .............................................. 48
FIGURE 9: OPERATING PRINCIPLE OF A TRANSITION EDGE SENSOR (TES). AFTER(8). ........................................ 50
FIGURE 10: SCHEMATIC OF A MICRO-CALORIMETER PIXEL (AS DEVELOPED AT SRON), CONSISTING OF AN X-RAY
ABSORBER (IN THIS CASE BI/CU), A PHASE TRANSITION THERMOMETER (IN THIS CASE TI/AU) AND A WEAK LINK
(SI3N4-MEMBRANE) TO THE BASE TEMPERATURE OF THE COOLER. AFTER (8). ....................................... 51
FIGURE 11: POSSIBLE LAYOUT OF THE XMS FIELD OF VIEW SHOWING THE DIFFERENCE BETWEEN THE INNER AND
OUTER ARRAY CLEARLY. THE OUTER PIXELS ARE TWICE AS LARGE AND 4 PIXELS ARE READ-OUT BY A SINGLE TES.
AFTER (8). ................................................................................................................................. 52
FIGURE 12: SCHEMATIC READ-OUT OF A SUPER PIXEL ILLUSTRATING THE DIFFERENCES IN THERMAL CONDUCTIVITY TO
THE ........................................................................................................................................... 52
FIGURE 13: CONCEPTUAL DESIGN OF THE FOCAL PLANE ASSEMBLY OF A MICROCALORIMETER, SHOWING THE VARIOUS
STEPS IN THE COOLING SYSTEM. THE FPA IS LAID OUT AS A CUBE. THE INNER, OUTER, AND ANTI-COINCIDENCE
DETECTORS ARE MOUNTED AT THE UPPER HORIZONTAL PLANE OF IT. ALONG THE SIDES OF THE CUBE THE COLD
ELECTRONICS ARE MOUNTED AND CONNECTED TO THE ELECTRICAL HARNESS. THE CENTRAL CUBE IS
SURROUNDED BY THERMAL AND MAGNETIC SHIELDS AT THE VARIOUS TEMPERATURE LEVELS. KEVLAR
SUSPENSION IS USED FOR THERMAL ISOLATION OF THESE TEMPERATURE STAGES. AFTER (7). ...................... 53