Hot-electron direct detector for radioastronomy

B. S. Karasik, W. R. McGrath, H. G. LeDuc, M. E. Gershenson

Research output: Contribution to journalConference articlepeer-review

39 Scopus citations


A hot-electron transition-edge superconducting bolometer with adjustable thermal relaxation speed is proposed. The bolometer contacts are made from a superconductor with high critical temperature which blocks the thermal diffusion of hot carriers into the contacts. Thus electron-phonon interaction is the only mechanism for heat removal. The speed of thermal relaxation for hot electrons in a nanometre-size superconducting bolometer with Tc = 100-300 mK is controlled by the elastic electron mean free path l. The relaxation rate behaves as T4l at subkelvin temperatures and can be reduced by a factor of 10-100 by decreasing l. Then an antenna- or waveguide-coupled bolometer with a time constant approx. 10-3-10-4 s will exhibit photon-noise-limited performance at millimetre and submillimetre wavelengths. The bolometer will have a figure of merit NEPτ 1/2 = 10-23-10-22 J-1 at 100 mK which is 103-104 times better (i.e. smaller) than that of a state-of-the-art bolometer. A tremendous increase in speed and sensitivity will have a significant impact for observational mapping applications.

Original languageEnglish (US)
Pages (from-to)745-747
Number of pages3
JournalSuperconductor Science and Technology
Issue number11
StatePublished - Nov 1999
EventProceedings of the 1999 International Superconductive Electronics Conference - Berkeley, CA, USA
Duration: Jun 21 1999Jun 25 1999

All Science Journal Classification (ASJC) codes

  • Ceramics and Composites
  • Condensed Matter Physics
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry


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