Detector and Optical Physics Group
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Cavendish Laboratory
Transition Edge Sensor
Bolometers
D. J. Goldie,
M. D. Audley, D. M. Glowacka, V. N. Tsaneva, S. Withington.
Detector Physics Group
at the
Cavendish Laboratory
DPG activities
•DPG capabilities
•Optical modelling
•Electromagnetics
•Thermal behaviour
•Device modelling
•Fabrication (Transition Edge Sensors (TESs), Kinetic
Inductance Detectors, SIS tunnel junctions, SQUIDs..
•Characterization
•Detector packaging
•This talk
•TESs for CMB polarization experiments
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
ClOVER TEAM
•Cambridge – M. D. Audley, B. Barker, M. Brown, M. Crane, D. Glowacka,
D. Goldie, K. Grainge, A. Lasenby, H. Stevenson, D. Titterington, V. Tsaneva,
S. Withington
•Cardiff – P.A.R Ade, P. G. Calisse, W. Gear, w. Grainger, P. Hargrave, J,
House, K. Isaac,, B. Kiernan, P. Mauskopf, S. Parsley, G. Savini, R. V.
Sudiwala, C. Tucker, R. Tucker, I. Walker, M. Whitehead, J. Zhang
•Manchester – L. Piccirillo, P. Diamond, A. Galtress, V. Haynes, P. Leahy,
S. Lewis, B. Maffei, L. Martinis, S. Melhuish, G. Pisano, R. Watson,
•Oxford – M. Brock, P. Cabella, P. Ferreira, P. Grimes, B. Johnson, M.
Jones, W. Lau, J. Leech, D. O’Dea, C. North, D. Sutton, A. Taylor, G. Yassin
•NIST- K. D. Irwin
•UBC- M. Halpern
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Key Features of CLOVER
• Two telescopes measuring polarization of CMB:
• LF: 97 GHz
• HF: combined 150 and 220 GHz focal plane
• Detectors: Bolometers with superconducting transition edge sensors (TES)
• Sensitivity:
limited by unavoidable photon noise (2.2x10-17 W/√Hz)
• Operating Temperature:
100 mK (active control of bath temperature)
• Focal Plane: hexagonal array of horns, two polarizations per horn
LF: 96 horns => 192 finline-coupled detectors at 97 GHz
HF: 192 horns => 192 4-probe OMTs in mixed 150/220 GHz focal plane
• Readout: Time-division SQUID multiplexer (NIST, UBC)
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Why Microstrip-coupled TESs?
• CLOVER needs high-performance polarimetry
• Flexibility: RF absorption is separated from the bolometer
• TES design can be optimised separately and doesn’t have to change
if the array architecture changes
• Calibration
• Can include planar band-pass filters, phase shifters, modulators etc.
=> simple detector becomes multi-function integrated circuit
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
ClOVER TES Detector Designs
•Finline-coupled detector, uses a
rectangular-waveguide to finline to
superconducting microstrip transition.
•Polarization-sensitive detector, which
uses probes suspended on a SiNx
membrane in a circular waveguide.
Waveguide
probes
Low frequency
Mid- and high frequency
Grounding ring
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
TESs for ClOVER
•Mo-Cu TESs
•500 nm SiNx support and
thermal isolation
•Tc 200 mK
•Tbath 100mK
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
ClOVER Science-Grade Detectors
30 chips per
wafer
Tc: 190 mK
Power handling: 11 pW
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Slotline coupled to microstrip
•Detail of the slotline-microstrip transition
•Single metalization layer for critical
dimensions
•Oxford design
TES Bolometers: CMB Workshop Cambridge July 2009
Detector Physics Group
at the
Cavendish Laboratory
Response of LF Detector to BB Illumination
IV Curves for different black-body temperatures
19
17
15
34 K
30 K
I (m A)
13
25 K
20 K
15 K
11
10 K
5K
1K
9
7
5
•Blackbody Illuminator
•Two low-pass filters define band
•Conical radiator
•Heat sunk to 1K stage
3
0
0.2
0.4
0.6
0.8
1
1.2
V (mV)
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Linearity at Fixed Bias
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Excess noise reduction
3G/4
G/4
Johnson
G2
•Current noise mainly from Johnson and thermal
sources alone.
•Little excess noise.
•
Dark NEP at 200 mK:
1.75x10-17 W/√Hz
with G= 172 pW/K
TES Bolometers: CMB Workshop Cambridge July 2009
Detector Physics Group
at the
Cavendish Laboratory
Effect of Dielectric Loading by Substrate
100% and
89%
efficiency
100 μm
225 μm
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Focal-Plane Module for ClOVER
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
LF Detector Module with OMTs
•Could already populate an 8*8 array
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
ClOVER HF CHANNEL
•150 and 220 GHz channels use probes
suspended on SiNx membrane across circular
waveguide
•Cardiff rf design
•Power from opposite probes combined onto a
single TES
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Four-probe OMT for HF instrument
Fully processed wafer with 150 GHz devices
TES Bolometers: CMB Workshop Cambridge July 2009
Detector Physics Group
at the
Cavendish Laboratory
Four-probe OMT for HF instrument
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Power Multiplexing
Nb3
Ins3
Nb1
Ins1
Nb2
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Response of Four-Probe OMT to Illuminator
4.5
4
Pdetected (pW)
3.5
3
2.5
2
1.5
1
0.5
0
0
5
10
15
T BB (K)
TES Bolometers: CMB Workshop Cambridge July 2009
20
25
30
Detector Physics Group
at the
Cavendish Laboratory
Materials Characterization I
•Johnson noise thermometry
•Thermal conductance studies
•Crucial for next generation low
background TESs
•K. Rostem et al. J Low Temp Phys (2008)
151: 76–81
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Materials Characterization II
•Heat capacity measurements
•Major implications for TES dark noise
•D. J. Goldie et al. J. Appl. Phys. 105, 074512 2009
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Materials Characterization III
•Lab on a chip 1st generation
•Wideband measurements of microstrip
losses
•K. Rostem et al. J. Appl. Phys. 105,
084509 2009
TES Bolometers: CMB Workshop Cambridge July 2009
Detector Physics Group
at the
Cavendish Laboratory
Materials Characterization IV
•Lab on a chip 2
•Thermal conductance
•How to make low G close-packed
arrays?
•Low G TESs for low power applications
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Optical Modelling
•Bolometer reception patterns
•Reduced pixel size
•C. N. Thomas, S. Withington
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
Summary ClOVER TESs
•Highly developed process route for microstrip coupled TESs
•High optical detection efficiency for both finline and probe-coupled designs
•Satisfy ClOVER requirements for dark NEP, power handling and response
time
•Packaging-shielding complete
•Integrated with time division MUX
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009
The FUTURE
•Recently kicked-off ESA TRP Cardiff/SRON/Maynooth/RAL
•Next generation TESs for space missions
•Far-IR TES detectors
•Ultra-low noise CMB B-mode detectors
•ClOVER a significant legacy
a significant opportunity
Detector Physics Group
at the
Cavendish Laboratory
TES Bolometers: CMB Workshop Cambridge July 2009