High energy resolution x-ray spectrometer for high count rate XRF applications
A new x-ray spectrometer has been constructed which incorporates a novel large area, low capacitance Si(Li) detector and a low noise JFET (junction field effect transistor) pr- eamplifier. The spectrometer operates at high count rates without the conventional compromise in energy resolution. For example, at an amplifier peaking time of 1 {mu}sec and a throughput count rate of 145,000 counts sec{sup {minus}1}, the energy resolution at 5.9 key is 220 eV FWHM. Commercially available spectrometers utilizing conventional geometry Si(Li) detectors with areas equivalent to the new detector have resolutions on the order of 540 eV under the same conditions. Conventional x-ray spectrometers offering high energy resolution must employ detectors with areas one-tenth the size of the new LBL detector (20 mm{sup 2} compared with 200 mm{sup 2}). However, even with the use of the smaller area detectors, the energy resolution of a commercial system is typically limited to approximately 300 eV (again, at 1 {mu}sec and 5.9 keV) due to the noise of the commercially available JFET`S. The new large area detector is useful in high count rate applications, but is also useful in the detection of weak photon signals, in which it is desirable to subtend as large an angle of the available photon flux as possible, while still maintaining excellent energy resolution. X-ray fluorescence data from the new spectrometer is shown in comparison to a commercially available system in the analysis of a dilute multi-element material, and also in conjunction with high count rate synchrotron EXAMS applications.
- Research Organization:
- Lawrence Berkeley Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 10191963
- Report Number(s):
- LBL-33955; CONF-9308179-1; ON: DE94000571; TRN: 93:025427
- Resource Relation:
- Conference: 42. annual Denver x-ray conference,Denver, CO (United States),2-6 Aug 1993; Other Information: PBD: Aug 1993
- Country of Publication:
- United States
- Language:
- English
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Large area, low capacitance Si(Li) detectors for high rate x-ray applications
Large area, low capacitance Si(Li) detectors for high rate x-ray applications
Related Subjects
74 ATOMIC AND MOLECULAR PHYSICS
X-RAY SPECTROMETERS
PERFORMANCE
COUNTING RATES
LI-DRIFTED SI DETECTORS
FIELD EFFECT TRANSISTORS
ENERGY RESOLUTION
SIZE
IRON 55
X-RAY SPECTRA
FLUORESCENCE
URANIUM
CHLORINE
440100
664200
RADIATION INSTRUMENTATION
SPECTRA OF ATOMS AND MOLECULES AND THEIR INTERACTIONS WITH PHOTONS