Translator Disclaimer
3 May 2002 Development of a new multielement detector system for megavoltage photons
Author Affiliations +
Abstract
Currently employed megavoltage photon detector systems in radiotherapy suffer from their low detection efficiency. This paper presents a new, more efficient approach. A dense converter material is placed along the direction of the photon beam together with the interspersed active medium. The high-energy electrons, generated in the converter material, create a detectable signal in the active medium. The characteristics of single detector element prototypes consisting of different brass tubes filled with either air or xenon were investigated. The significance of the wall thickness and material of a two-dimensional array of such elements was analyzed by Monte Carlo studies. Saturation curves and the signal as a function of the gas pressure illustrate the equivalence of the prototypes to conventional ionization chambers. A high-density gas like xenon at a high pressure is required to get a sufficiently large signal-to-noise ratio. Acquired MVCT slice images revealed contrasts of - 2.4 percent at a dose of 40 cGy. Monte Carlo calculations suggest an optimal wall thickness of a few hundred micrometers for an element width of 1.5 mm. The superiority of high density and high atomic number materials like tungsten in terms of the amount of primary signal recorded and the extent of crosstalk is demonstrated.
© (2002) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ralf Hinderer, Jeff Kapatoes, Harald Keller, Richard Schmidt, Robert Jeraj, Kenneth J. Ruchala, David W. Pearson, Guang Fang, Gustavo Olivera, and Thomas Mackie "Development of a new multielement detector system for megavoltage photons", Proc. SPIE 4682, Medical Imaging 2002: Physics of Medical Imaging, (3 May 2002); https://doi.org/10.1117/12.465632
PROCEEDINGS
10 PAGES


SHARE
Advertisement
Advertisement
RELATED CONTENT

G-MAP: a novel night vision system for satellites
Proceedings of SPIE (October 11 2015)
New Developments In Digital X-Ray Detection
Proceedings of SPIE (November 03 1981)
Initial results on calorimetry and imaging of MeV gamma rays...
Proceedings of SPIE (September 20 1994)
Single-sided CZT strip detectors
Proceedings of SPIE (September 28 2004)

Back to Top