P5. Cold-Electron Bolometer Array (CEB Array) made by E-Beam Lithography and a Shadow Evaporation Technology

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Bolometer Group
Through the thorns to the stars! Igenom törnen
mot stjärnorna! ????? ?????? ? ???????!
Chalmers University of Technology

• P5. Cold-Electron Bolometer Array (CEB Array)
  made by E-Beam Lithography and a Shadow
  Evaporation Technology

Leonid Kuzmin and Ian Agulo
FKA190
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Bolometer Group
Chalmers University of Technology

• Superconducting Cold-Electron Bolometer with JFET
  readout for OLIMPO balloon telescope

Leonid Kuzmin, Philip Mauskopf , and Dmitry
Golubev Cardiff University, UK Karlsruhe
Forschungszentrum, Germany
EUCAS -2005
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3-layer technology
JFET Voltage- biased
SCEB
OLIMPO Cardiff
2-layer Al-Ti Direct Write technology
CEB- Series array
JFET Current -biased
2-layer Ti-Al Direct Write technology
CEB
CLOVER others Oxford
SQUID
Shadow Evaporation Technology
CEB- Parallel array

• CLOVER
• Phase Switch
• Oxford,
• Cardiff

NbN Nanostrip Finline
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Balloon telescope OLIMPO (follower of BOOMERanG)

• a multi-wavelength survey of galaxy clusters and
  the cosmic submm/mm background
• 2.6 meter antenna
• A few arcmin resolution survey of the sky
• 150, 220 350, 600 GHz (Background load Po 3 -
  20 pW
• Background limited bolometers (210-17 110-16
  W/Hz1/2),
• 64 bolom. per channel
• Bolometers TESSQUID readout
• SiNJFET readout
• CEBJFET (or SQUID) readout
• Rome Un., Cardiff Un., IROE-CNR (Italy), Caltech
  (USA), Santa Barbara Un. , DAFNIA/SPP (France),
  Tel Aviv Un., VTT (finland), Chalmers Univ.

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Balloon telescope OLIMPO

• 1. Channel I 2.1 mm (140 GHz)
• Power load is relatively high P0 2 3 pW
• Photon noise
• Total NEP of CEB should be less than photon
  noise NEPtot lt NEPphot.
• Single CEB doesnt give proper results.
• Only SCEB could give the proper NEP.

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Cold-Electron Bolometer (CEB) with Capacitive
Coupling to the Antenna Kuzmin ISSTT-98
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Readout Systems for CEB current measurements
SQUID with a bulk input transformer - most sensitive - very complicated Chalmers Un., IREE, IZMIRAN, MSU, VTT (Finland)
JFET _at_ 4K - sensitive current measurements - but high voltage noise - promising with S-I-S-I-S bolometers Chalmers Un., Cardiff Un, IREE, Rome Un.
HEMT _at_ 4K with resonance circuits - good for multiplexing - need modulation technique IPHT (Jena), Chalmers Un., CESR (Toulouse)

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CEB with JFET
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Cold-Electron Bolometer Noise
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JFET amplifier noise
We need matching with
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Capacitively Coupled Superconducting
Cold-Electron Bolometer (SCEB)
L. Kuzmin, Microelectronic Engineering, 69 (2003)
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SCEB with JFET
Total NEP is less than NEPphot for SCEB, total
iJFET10 fA/Hz1/2, R0.5 kOhm and 0.1 kOhm (one
junction), Vol0.05um3, power load 2 pW.
IV curves are shown for estimation of high
dynamic resistance of the junctions.
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Series Array of CEBs with JFET readout
Circle waveguide is coupled to 4 coplanar
lines Each Coplanar line is coupled to 2 CEBs
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CEB, Current-biased, Array - 10 junctions
Total NEP is less than NEPphot vJFET2nV/Hz1/2
R0.5 kOhm (one junction), Vol0.02um3, power
load2 pW The power is split between bolometers
and responsivity is considerably improved.
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Total NEP of CEB and NEPphot for series array
CEBs in dependence on number of CEBs
a) 600 GHz, power load P0 20 pW, vJFET3
nV/Hz1/2 R0.5 kOhm Vol0.05um3 Optimal number of
CEBs 20-50. b) 140 GHz, power load P0 2 pW,
vJFET2 nV/Hz1/2 R0.5 kOhm Vol0.02um3. Optimal
number of CEBs 5-10.
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JFET in current-biased mode. Variants

• Series array of CEBs
• Array of SINIS structures without biasing
• Array of SN NS Andreev contacts thermo-voltage
  without biasing
• Array of thermocouples (thermo-pile)
• Combination of thermocouples and superconducting
  islands (SN Andreev contacts)
• Array of CEBs series for DC
• - parallel for HF

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Series Array of CEBs with JFET readout
Parallel for HF
HF
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Conclusions
New generation of detectors is needed to measure
Cosmic Microwave Background (OLIMPO project)
Cold-Electron Bolometer (CEB) with JFET readout
very attractive option! Single CEB with JFET
no chance! Array of CEBs with JFET the most
attractive opportunity SCEB (Superconducting
Cold-Electron Bolometer) with JFET realistic
and effective decision