A new area multidetector dosemeter for mixed n-  fields

Abstract

A new instrument to assess neutron ambient doses has been designed and constructed. In its design, spectrometric capabilities have been implemented that allow to take into account the energy spectrum of the neutron field in the evaluation of the operational magnitude, ambient dose equivalent, H*(10). This dosemeter is based on the moderation-absorption technique and can be employed over a wide range of energies from thermal to 20 MeV. It consists of a spherical shaped polyethylene moderator with a set of thermoluminescence dosemeters (TLDs) inserted in different positions of its interior to evaluate the external neutron energy spectrum. At this moment the system uses pairs 6LiF:Mg,Ti (TLD-600) and 7LiF:Mg,Ti (TLD-700) thermoluminescence dosemeters for a better gamma discrimination. The dosemeter response matrix was calculated using the MCNP4C Monte Carlo code (MC). The viability of the dosemeter for area dosemetry has been examined experimentally showing its capabilities over a wide range of energies.

Experimental Determination of Peripheral Doses for Different IMRT Techniques Delivered by a Siemens Linear Accelerator

“…Measurements were performed with two kinds of TLDs, TLD-600 and TLD-700, in order to be able to quantify photon and neutron PD components separately [8,9,11,15,16,23]. The TLD-700 is only used for photon detection while TLD-600 is sensitive to photons and neutrons.…”

Estimation of neutron-equivalent dose in organs of patients undergoing radiotherapy by the use of a novel online digital detector

“…The methodology employed to analyse all the experimental glow curves obtained was based on the numerical techniques developed by Gómez-Ros (1990, 1992) and Muñiz et al (1999Muñiz et al ( , 2004. On the basis of the results of this glow curve analysis, thermal neutron fluences were obtained using the differences between TLD-600 and TLD-700 results for each measured point in NORMA (R) and the calibration factors as follows:…”

Design and feasibility of a multi-detector neutron spectrometer for radiation protection applications based on thermoluminescent 6LiF:Ti,Mg (TLD-600) detectors

“…1). The TLD-600 (LiF:Ti,Mg) dosimeters were 0.3 Â 0.3 Â 0.09 cm 3 chips with 94.9% of 6 Li and 5.1% of 7 Li and a density of 2.64 g/cm 3 [7], each one located at the given positions (0, 73, 76, 79 and 712 cm in the three orthogonal axis) within a hole of the same size in the PE sphere.…”

“…Following this idea, the purpose of this work is to present a preliminary study to evaluate the feasibility of a detector consisting of a single polyethylene (PE) sphere with 6 LiF:Ti,Mg (TLD-600) thermoluminescent (TL) dosimeters [7,8] arranged along three perpendicular axis within a single PE sphere, calculating the response functions for monoenergetic neutrons in the energy range from 10 À8 to 100 MeV using the Monte Carlo (MC) code MCNPX 2.5 and testing the feasibility of the device for neutron spectrometry by the unfolding of simulated exposure to different neutron sources.…”