Hostname: page-component-848d4c4894-mwx4w Total loading time: 0 Render date: 2024-06-29T20:35:26.897Z Has data issue: false hasContentIssue false

High Energy Resolution X-Ray Spectrometer for High Count Rate Xrf Applications

Published online by Cambridge University Press:  06 March 2019

C. S. Rossington
Affiliation:
Lawrence Berkeley Laboratory University of California Berkeley, CA 94720
N. W. Madden
Affiliation:
Lawrence Berkeley Laboratory University of California Berkeley, CA 94720
K. Chapman
Affiliation:
Lawrence Berkeley Laboratory University of California Berkeley, CA 94720
Get access

Abstract

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) preamplifier. The spectrometer operates at high count Tates without the conventional compromise in energy resolution. For example, at an amplifier peaking time of 1 p.sec and a throughput count rate of 145,000 counts sec-1, the energy resolution at 5.9 keV 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 mm2 compared with 200 mm2). 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 μsec 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 die new spectrometer is shown in comparison to a commercially available system in the analysis of a dilute muhi-element material, and also in conjunction with high count rate synchrotron EXAFS applications.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Goulding, F. S. and Landis, D. A., Semiconductor detector spectrometer electronics, in: “Nuclear Spectroscopy and Reactions, Part A,” J. Cerny, ed., Academic Press, New York (1974).Google Scholar
2. Rossington, C. S., Fine, P. M. and Madden, N. W., Large area, low capacitance Si(Li) detectors for high rate x-ray applications, LBL report #32243, accepted for publication in IEEE Trans. Nucl. Sci. Google Scholar
3. Nashashibi, T. and White, G., A low noise FET with integrated charge restoration for radiation detectors, IEEE Trans. Nucl. Sci. 37(2):452 (1990).Google Scholar
4. Hanson, A. L., The polarization of x-rays scattered into 90°, Nucl. Instr. and Meth. A249: 515, (1986).Google Scholar
5. Janssens, K., Monte Carlo simulation of synchrotron radiation induced x-ray fluorescence spectra: a useful tool for spectrometer design and calibration, presented at the Denver X-ray Conference, Denver, CO, Aug. 2-6, 1993.Google Scholar
6. de Rose, V., private communication.Google Scholar
7. Wobrauschek, P., private communication.Google Scholar