Abstract
The Advanced Detector Group at LLNL is developing superconducting Nb-Al-AlOx-Al-Nb tunnel junction detector arrays for high-resolution soft X-ray spectrometry. We have characterized the detector response function in the energy range between 50 and 2000 eV with monochromatic X-rays, in collaboration with the Physikalisch-Technische Bundesanstalt Laboratory at the BESSY II electron storage ring. The detectors have an energy resolution between 7 and 15 eV FWHM in that energy range, and a count rate capability of ∼10,000 counts/s per detector pixel. In addition, the detector response function exhibits several spectral artifacts, and although their magnitude is only on the order of 1% of the main line, they can reduce the sensitivity for X-ray analysis of dilute specimens if they overlap with the correspondingly weak emission lines. We have characterized these artifacts by scanning a collimated synchrotron radiation beam across the detector area. We identify their origin due to X-ray absorption at locations other than the main Nb absorber film, and outline future detector designs to reduce the artifacts and thereby extend the spectrometer sensitivity.
Original language | English (US) |
---|---|
Pages (from-to) | 35-45 |
Number of pages | 11 |
Journal | Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |
Volume | 551 |
Issue number | 1 |
DOIs | |
State | Published - Oct 1 2005 |
Externally published | Yes |
Event | Proceedings of the E-MRS Fall Meeting 2004, Symposium D Applications of Linear and Area Detectors for X-Ray and Neutron Diffraction - Duration: Sep 6 2004 → Sep 10 2004 |
Keywords
- STJ line shapes
- STJ response functions
- Superconducting devices
- Superconducting tunnel junctions
- Synchrotron detectors
- X-ray spectrometers
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Instrumentation