Development of Ta-based Superconducting Tunnel Junction X-ray Detectors for Fluorescence XAS

Conference · Wed Sep 23 04:00:00 EDT 2009

DOI:https://doi.org/10.1063/1.3463152· OSTI ID:970149

Friedrich, S; Drury, O; Hall, J; Cantor, R

We are developing superconducting tunnel junction (STJ) soft X-ray detectors for chemical analysis of dilute samples by fluorescence-detected X-ray absorption spectroscopy (XAS). Our 36-pixel Nb-based STJ spectrometer covers a solid angle {Omega}/4{pi} {approx} 10{sup -3}, offers an energy resolution of {approx}10-20 eV FWHM for energies up to {approx}1 keV, and can be operated at total count rates of {approx}10{sup 6} counts/s. For increased quantum efficiency and cleaner response function, we have now started the development of Ta-based STJ detector arrays. Initial devices modeled after our Nb-based STJs have an energy resolution below 10 eV FWHM for X-ray energies below 1 keV, and pulse rise time discrimination can be used to improve their response function for energies up to several keV. We discuss the performance of the Ta-STJs and outline steps towards the next-generation of large STJ detector arrays with higher sensitivity.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 970149
• Report Number(s): LLNL-PROC-420848
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ABSORPTION SPECTROSCOPY
CHEMICAL ANALYSIS
ENERGY RESOLUTION
FLUORESCENCE
PERFORMANCE
PULSE RISE TIME
QUANTUM EFFICIENCY
RESPONSE FUNCTIONS
SENSITIVITY
SPECTROMETERS
SYNCHROTRON RADIATION