Share Email Print
cover

Proceedings Paper

A wide-acceptance Compton spectrometer for spectral characterization of a medical x-ray source
Author(s): Michelle A. Espy; A. Gehring; A. Belian; T. Haines; J. Hunter; M. James; M. Klasky; J. Mendez; D. Moir; R. Sedillo; R. Shurter; J. Stearns; K. Van Syoc; P. Volegov
Format Member Price Non-Member Price
PDF $17.00 $21.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Accurate knowledge of the x-ray spectra used in medical treatment and radiography is important for dose calculations and material decomposition analysis. Indirect measurements via transmission through materials are possible. However, such spectra are challenging to measure directly due to the high photon fluxes. One method of direct measurement is via a Compton spectrometer (CS) method. In this approach, the x-rays are converted to a much lower flux of electrons via Compton scattering on a converter foil (typically beryllium or aluminum). The electrons are then momentum selected by bending in a magnetic field. With tight angular acceptance of electrons into the magnet of ~ 1 deg, there is a linear correlation between incident photon energy and electron position recorded on an image plate. Here we present measurements of Bremsstrahlung spectrum from a medical therapy machine, a Scanditronix M22 Microtron. Spectra with energy endpoints from 6 to 20 MeV are directly measured, using a CS with a wide energy range from 0.5 to 20 MeV. We discuss the sensitivity of the device and the effects of converter material and collimation on the accuracy of the reconstructed spectra. Approaches toward improving the sensitivity, including the use of coded apertures, and potential future applications to characterization of spectra are also discussed.

Paper Details

Date Published: 22 March 2016
PDF: 11 pages
Proc. SPIE 9783, Medical Imaging 2016: Physics of Medical Imaging, 97834V (22 March 2016); doi: 10.1117/12.2216269
Show Author Affiliations
Michelle A. Espy, Los Alamos National Lab. (United States)
A. Gehring, Los Alamos National Lab. (United States)
A. Belian, Los Alamos National Lab. (United States)
T. Haines, Los Alamos National Lab. (United States)
J. Hunter, Los Alamos National Lab. (United States)
M. James, Los Alamos National Lab. (United States)
M. Klasky, Los Alamos National Lab. (United States)
J. Mendez, Los Alamos National Lab. (United States)
D. Moir, Los Alamos National Lab. (United States)
R. Sedillo, Los Alamos National Lab. (United States)
R. Shurter, Los Alamos National Lab. (United States)
J. Stearns, Los Alamos National Lab. (United States)
K. Van Syoc, Los Alamos National Lab. (United States)
P. Volegov, Los Alamos National Lab. (United States)


Published in SPIE Proceedings Vol. 9783:
Medical Imaging 2016: Physics of Medical Imaging
Despina Kontos; Thomas G. Flohr, Editor(s)

© SPIE. Terms of Use
Back to Top