The gamma-ray imaging spectrometer (GRIS) we have assembled comprises four coaligned, independent imagers, each with its own detector and coded-aperture mask (Figure 1). Each detector “sees” incoming gamma rays only through its mask, which serves as the imaging optic for the gamma rays (see box, pp. 1819). This mask is mounted on a movable mask plate in front of the detector plane; moving the p...

background: prompt gamma neutron activation analysis (pgnaa) is known as a non-invasive technique capable of measuring elemental concentration in voluminous samples in a short period of time. also it is a valuable diagnostic tool for total body elemental measurements. 252cf and 241am-be sources which are usually used in this method, generate not only neutrons, but also emit high-energy and unwa...

Background: A Boron Neutron Capture Therapy (BNCT) facility, based on a DT neutron generator, with the final goal to find out a potential, alternative, solution to existing BNCT treatment facilities which are based on nuclear reactors is examined. Materials and Methods: With the aim of the MCNP4B Monte Carlo code different beam-shaping assembly (BSA) configurations were considered. Lead was sel...

This article reviews the present status of high energy γ-ray astronomy at energies above 30 MeV. Observations in the past decade using both spaceand ground-based experiments have been primarily responsible for giving a tremendous boost to our knowledge of the high energy Universe. High energy γ-rays have been detected from a wide range of Galactic and extragalactic astrophysical sources, such a...

background: this cross sectional study was conducted to evaluate the effect of &gamma-rays; and electron-beam irradiation with a commercial toxin binder-milbond-tx on the performance, feed components, and meat quality of japanese quails challenged with aflatoxin b1. methods: overall, 168 one-d-old chicks (japanese quails) were allocated to eight treatments with three replicates based on a compl...

Three algorithms for discriminating between fast neutrons, thermal neutrons and gamma rays in a Li loaded plastic scintillator have been compared. Following a literature review of existing pulse shape discrimination techniques, the performance of the charge comparison method, triangular filtering and frequency gradient analysis were investigated in this work. The scintillator was exposed to thr...

A position sensitive detector for 9 MeV gamma rays has been developed as part of a contraband detection system for airports. The system images contraband, such as explosives or drugs, in a geometry similar to medical x-ray computed tomography. A point source of gamma rays shines through an unknown object. Transmission projections of the areal density of detected gamma rays are reconstructed int...

in order to improve the performance of a newly developed radiochromic film, gic-79, somedosimetric characteristics of this film have been studied based on relevant standard practice. the presentstudy describes some parameters that may affect the dosimeter response before, during, and after irradiation. the effect of absorbed dose rate on dosimeter response was determined by irradiating dosimete...