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Title: Energy dependence of commercially available diode detectors for in-vivo dosimetry

Abstract

The energy dependence of commercially available diode detectors was measured for nominal accelerating potential ranging between Co-60 and 17 MV. The measurements were performed in a liquid water phantom at 5 cm depth for 10x10 cm{sup 2} collimator setting and source-to-detector distance of 100 cm. The response (nC/Gy) was normalized to Co-60 beam after corrections for the dose rate and temperature dependences for each diode. The energy dependence, calculated by taking the percent difference between the maximum and minimum sensitivity normalized to Co-60 beam, varied by 39% for the n-type Isorad Red, 26% for the n-type Isorad Electron, 19% for the QED Red (p-type), 15% for the QED Electron (p-type), 11% for the QED Blue (p-type), and 6% for the EDP10 diode for nominal accelerating potential between Co-60 and 17 MV. It varied by 34% for the Isorad-3 Gold 1 and 2, 35% for the Veridose Green, 15% for the Veridose Yellow, 9% for the Veridose Electron, 21% for the n-type QED Gold, 24% for the n-type QED Red, 3% for the EDP2{sup 3G}, 2% for the PFD (photon field detector), 7% for the EDP10{sup 3G}, and 16% for the EDP20{sup 3G} for nominal accelerating potential between Co-60 and 15more » MV. The magnitude of the energy dependence is verified by Monte Carlo simulation. We concluded that the energy dependence does not depend on whether the diode is n- or p-type but rather depends mainly on the material around the die such as the buildup and the geometry of the buildup material. As a result, the value of the energy dependence can vary for each individual diode depending on the actual geometry and should be used with caution.« less

Authors:
;  [1];  [2]
  1. Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, University of South Florida, Tampa, Florida 33612 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
20951301
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 34; Journal Issue: 5; Other Information: DOI: 10.1118/1.2719365; (c) 2007 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
61 RADIATION PROTECTION AND DOSIMETRY; COBALT 60; COLLIMATORS; COMPUTERIZED SIMULATION; DOSE RATES; DOSEMETERS; DOSIMETRY; ENERGY DEPENDENCE; GEOMETRY; GOLD; IN VIVO; MONTE CARLO METHOD; PHANTOMS; QUANTUM ELECTRODYNAMICS; TEMPERATURE DEPENDENCE

Citation Formats

Saini, Amarjit S., Zhu, Timothy C., and Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104. Energy dependence of commercially available diode detectors for in-vivo dosimetry. United States: N. p., 2007. Web. doi:10.1118/1.2719365.
Saini, Amarjit S., Zhu, Timothy C., & Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104. Energy dependence of commercially available diode detectors for in-vivo dosimetry. United States. doi:10.1118/1.2719365.
Saini, Amarjit S., Zhu, Timothy C., and Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104. Tue . "Energy dependence of commercially available diode detectors for in-vivo dosimetry". United States. doi:10.1118/1.2719365.
@article{osti_20951301,
title = {Energy dependence of commercially available diode detectors for in-vivo dosimetry},
author = {Saini, Amarjit S. and Zhu, Timothy C. and Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104},
abstractNote = {The energy dependence of commercially available diode detectors was measured for nominal accelerating potential ranging between Co-60 and 17 MV. The measurements were performed in a liquid water phantom at 5 cm depth for 10x10 cm{sup 2} collimator setting and source-to-detector distance of 100 cm. The response (nC/Gy) was normalized to Co-60 beam after corrections for the dose rate and temperature dependences for each diode. The energy dependence, calculated by taking the percent difference between the maximum and minimum sensitivity normalized to Co-60 beam, varied by 39% for the n-type Isorad Red, 26% for the n-type Isorad Electron, 19% for the QED Red (p-type), 15% for the QED Electron (p-type), 11% for the QED Blue (p-type), and 6% for the EDP10 diode for nominal accelerating potential between Co-60 and 17 MV. It varied by 34% for the Isorad-3 Gold 1 and 2, 35% for the Veridose Green, 15% for the Veridose Yellow, 9% for the Veridose Electron, 21% for the n-type QED Gold, 24% for the n-type QED Red, 3% for the EDP2{sup 3G}, 2% for the PFD (photon field detector), 7% for the EDP10{sup 3G}, and 16% for the EDP20{sup 3G} for nominal accelerating potential between Co-60 and 15 MV. The magnitude of the energy dependence is verified by Monte Carlo simulation. We concluded that the energy dependence does not depend on whether the diode is n- or p-type but rather depends mainly on the material around the die such as the buildup and the geometry of the buildup material. As a result, the value of the energy dependence can vary for each individual diode depending on the actual geometry and should be used with caution.},
doi = {10.1118/1.2719365},
journal = {Medical Physics},
number = 5,
volume = 34,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}