Date of Award

2009-01-01

Degree Name

Master of Science

Department

Physics

Advisor(s)

Miguel Castro-Colin

Abstract

This present work relates to the study and characterization of the response function of an energy-dispersive x-ray spectrometer. The problems of energy, efficiency and resolution calibration of the system operating in the energy (5-60 keV) range are discussed. We present the operation characteristics of the portable pyro-electric x-ray generator (COOL-X) and the application of the calibrated response spectrum in the elemental analysis using X-ray Fluorescence (XRF).

We study the response of the Si(Li)-Pin XR-100CR semiconductor detector to low energy photons. The photopeak efficiency was determined experimentally by using radioisotopes and compared against a theoretical efficiency curve. The efficiency for gamma photons resulting from the decay of the radioactive sources and that of x-rays, was obtained from direct measurements. The response characteristics of CdTe XR-100T detector and the efficiency calculations are performed using standard radioactive sources. Escape events originated in this detector are observed and discussed. The comparison between the detectors and the advantages and disadvantages for XRF are described, together with a discussion of suggested features or expected complications that may arise given certain parameters of the detectors.

We present a brief analysis of elemental content carried out by means of a pyro-electric generator in combination with a CdTe and a Si(Li)-Pin energy dispersive detectors. The setup presented here can be easily assembled in an average laboratory to observe the effect of X-rays as they interact with matter to yield a characteristic fingerprint, a phenomenon that directly relates to atomic theory. In the present case three pieces of metal whose elemental content has been characterized were analyzed and their elemental content shown. Additionally we performed the elemental analysis using a Si(Li)-Pin detector on standard reference materials and their elemental energy lines have been identified. These results have been compared with those obtained from an X-ray analysis system XMET 3000 TXV, also based on a Si-Pin detector but with a Silver X-ray excitation source.

Language

en

Provenance

Received from ProQuest

File Size

149 pages

File Format

application/pdf

Rights Holder

sunil kumar Valaparla

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