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Electrical NEP in Hot-Electron Titanium Superconducting BolometersWe are presenting the current progress on the titanium (Ti) hot-electron transition-edge devices. The ultimate goal of this work is to develop a submillimeter Hot-Electron Direct Detector (HEDD) with the noise equivalent power NEP = 10(sup -1) - 10(sup -20) W/Hz(sup 1/2) for the moderate resolution spectroscopy and Cosmic Microwave Background (CMB) studies on future space telescope (e.g., SPICA, SAFIR, SPECS, CMBPol) with cryogenically cooled (approximately 4-5 K) mirrors. Recently, we have achieved the extremely low thermal conductance (approximately 20 fW/K at 300 mK and approximately 0.1 fW/K at 40 mK) due to the electron-phonon decoupling in Ti nanodevices with niobium (Nb) Andreev contacts. This thermal conductance translates into the "phonon-noise" NEP approximately equal to 3 x 10(sup -21) W/Hz(sup 1/2) at 40 mK and NEP approximately equal to 3 x 10(sup -19) W/Hz(sup 1/2) at 300 mK. These record data indicate the great potential of the hot-electron detector for meeting many application needs. Beside the extremely low phonon-noise NEP, the nanobolometers have a very low electron heat capacitance that makes them promising as detectors of single THz photons. As the next step towards the practical demonstration of the HEDD, we fabricated and tested somewhat larger than in Ref.1 devices (approximately 6 micrometers x 0.35 micrometers x 40 nm) whose critical temperature is well reproduced in the range 300-350 mK. The output electrical noise measured in these devices with a low-noise dc SQUID is dominated by the thermal energy fluctuations (ETF) aka "phonon noise". This indicates the high electrothermal loop gain that effectively suppresses the contributions of the Johnson noise and the amplifier (SQUID) noise. The electrical NEP = 6.7 x 10(sup -18) W/Hz(sup 1/2) derived from these measurements is in good agreement with the predictions based on the thermal conductance data. The very low NEP and the high speed (approximately microns) are a unique combination not found in other detectors.
Document ID
20150008663
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Karasik, Boris S.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Pereverzev, Sergey V.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Olaya, David
(Rutgers Univ. Piscataway, NJ, United States)
Wei, Jian
(Rutgers Univ. Piscataway, NJ, United States)
Gershenson, Michael E.
(Rutgers Univ. Piscataway, NJ, United States)
Sergeev, Andrei V.
(State Univ. of New York Buffalo, NY, United States)
Date Acquired
May 20, 2015
Publication Date
June 23, 2008
Subject Category
Instrumentation And Photography
Meeting Information
Meeting: SPIE Conference on Astronomical Telescopes and Instrumentation
Location: Marseille
Country: France
Start Date: June 23, 2008
End Date: June 28, 2008
Sponsors: International Society for Optical Engineering
Distribution Limits
Public
Copyright
Other
Keywords
transition-edge sensor
terahertz astronomy

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