In this paper we describe the development and testing of instruments to measure singlet molecular oxygen produced by the photodynamic process. Singlet oxygen is an active species in photodynamic therapy, and we are developing two instruments for PDT researchers with the goal of a real-time dosimeter for singlet oxygen. We discuss both an ultrasensitive point sensor, and an imaging system that p...

A new instrument was developed to measure radon exposure with the use of passive monitors like nuclear track etch detectors. It is based on a device to be switched on and off to permit accurate measurements of timed exposures. The detector arrangement consists of a small cylindrical chamber, a mobile piston inside, a filter holder, a detector holder. The internal sampling volume is variable. Th...

INTRODUCTION The angular dependency of response for TLD cards may cause deviation from its true value on the results of environmental dosimetry, since TLDs may be exposed to radiation at different angles of incidence from the surrounding area. OBJECTIVE A 3D setting of TLD cards has been calibrated isotropically in a standard radiation field to evaluate the improvement of the accuracy of meas...

PURPOSE The commissioning of treatment planning systems and beam modeling requires measured input parameters. The measurement of relative output in-air, Sc is particularly difficult for small fields. The purpose of this study was to investigate the influence of miniphantom design and detector selection on measured Sc values for small fields and to validate the measurements against Monte Carlo s...

Previous research has proven that the Poly (2,6-dimethyl-1, 4-phenylene oxide) (PPO) dosimeter is capable of receiving both in-air and underwater UV exposures that are significantly greater than those of the more commonly used polysulphone dosimeter, within a range of accuracy close to what would be expected of dosimetric measurements made in-air provided that the necessary calibrations are com...

Accurate dose measurement tools are needed to evaluate the radiation dose delivered to patients by using modern and sophisticated radiation therapy techniques. However, the adequate tools which enable us to directly measure the dose distributions in three-dimensional (3D) space are not commonly available. One such 3D dose measurement device is the polymer-based dosimeter, which changes the mate...

The response of high-dose-range chemical dosimeters is dependent on the dosimeter temperature during irradiation. Typically, irradiation temperatures are estimated by measurements, calculations, or some combination of the two. Then using the temperature coefficient for the dosimetry system, the dosimeter response is adjusted or corrected to be consistent with the irradiation temperature for the...

This study was conducted as part of a project involving the evaluation of a new type of noise exposure monitoring paradigm. Laboratory tests were conducted to assess how "nonstandard" dosimeter microphones and microphone positions measured noise levels under different acoustical conditions (i.e., diffuse field and direct field). The data presented in this article reflect measurement differences...

Background: Different kinds and models of personal dosimeters are used in individual monitoring by workers.  Performance testing as part of approval procedures is carried out to demonstrate that the essential performance specifications are routinely maintained. There are four service providers in Iran which use different luminescence techniques (i. e. TLD and RPL) with various kinds of dos...

background: an effective polymer gel dosimeter can be fabricated by varying the composition of its chemical components. materials and methods: the magat gel dosimeter formulations that used different compositions of methacrylic acid (maa) and gelatin were extensively investigated in the present study according to the r2–dose response and r2–dose sensitivity. the irradiation of magat gel was per...