http://ieeexplore.ieee.org/iel5/10933/35792/01697964.pdf

Ionization Chambers

Variance reduction technique in a beta radiation beam using an extrapolation chamber.

1. Introduction to health and safety

Colorimetric detection of low dose gamma radiation based on the aggregation of gold nanoparticles and its application for the blood irradiation

This work present the experimental characteristics study of the versatile gamma ionization chamber that is designed, developed and distinguished in our laboratory. All tests were accomplished under the International Electro-technical Commission. The saturation current curves and the linearity were plotted by determining the operating range and the sensitivity of the chamber. The response is linear up to more than 10 Sv/h. The sensitivity of the experimentally measured chamber is 2.1 × 10−8 A per Sv/h at an argon gas pressure of 0.4 MPa. In the same conditions, a comparative characterization with a reference chamber LND504 (USA) was done.

Design and study of the characteristics of a versatile ionization chamber for gamma-ray dosimetry

Extrapolation chamber is the only primary standard dosimeter for beta radiation. With the aim to test new configurations and materials using easily-available and low-cost materials and fulfill the need of a chamber for scientific metrological purposes, in this paper the prototype of an extrapolation chamber has been built and its performance has been investigated in the beta radiation field of 90Sr+90Y. The main differences between the chamber and commercially available chambers are the geometry, constituent material and configuration. The obtained results were compared with those of the calibration certificate of the source and an agreement within 4 % was verified. The depth-dose curve was also obtained and compared with the curve published in ISO 6980, showing a good agreement. Moreover, Monte Carlo simulation was undertaken using MCNP4C code and the relative difference of 0.3 % was observed compared to the experiment. All of the results proved the suitability of the chamber in the beta radiation field of 90Sr+90Y.

A prototype of an extrapolation chamber for beta radiation beams of 90Sr+90Y

A prototype of an ionization chamber for gamma radiation beams of 60Co: Experimental and Monte Carlo preliminary results

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.

/pdf/the-calibration-and-use-of-a-new-ring-shaped-ionization-fjd9s71mwy.pdf

Anita Alipoor

Papers

A prototype of an extrapolation chamber for beta radiation beams of 90Sr+90Y

A prototype of an ionization chamber for gamma radiation beams of 60Co: Experimental and Monte Carlo preliminary results

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