The Calibration and Use of a New Ring-Shaped Ionization Chamber for Monitoring and Dosimetry of X-Ray Beams

Babak Sharifi¹, Hossein Zamani Zeinali^2*, Anita Alipoor², Arjang Shahvar¹, Ali Negarestani¹

¹Graduate University of Advanced Technology, Kerman, Iran.
²Radiation Application Research School, Nuclear Science and Technology Research Institute, AEOI, Karaj, Iran.

DOI: 10.4236/wjnst.2015.53020                

Abstract

Today, dosimeters are used generally for dosimetry of the diagnostic X-ray beam. Ionization chambers are appropriate instruments for monitoring and also the dosimetry of X-ray beam in medical diagnostic equipment. The present work introduces design and investigation of a new ring-shaped monitor chamber with a PMMA body, graphite-coated PMMA windows (0.5 mm thick), a special graphite-foil central electrode (0.1 mm thick, 0.7 g/cm³ dense) that creating two sensitive volumes and a central hole for crossing the radiation beam with less attenuation. The results of performance tests conducted at the Nuclear Science and Technology Research Institute, AEOI in Karaj- Iran proved the high short and long-term stability, the very low leakage current, the low directional dependence and very high ion collection efficiency through the special design of the collecting electrode. Moreover, the FLUKA Monte Carlo simulations certified the negligible effect of central electrode on this new ring-shaped monitor chamber. According to the results of the performance tests, the new monitor chamber can be used as a standard dosimeter in order to monitor X-ray beam in primary standard dosimetry laboratories.

Keywords

Ring-Shaped Monitor Chamber, Diagnostic X-Ray Beam, Quality Control Tests, Low Dens Graphite-Foil, Central Electrode

Conflicts of Interest

The authors declare no conflicts of interest.

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