background: boron and gadolinium are among the nuclides that hold a unique property of being a neutron capture therapy agent. neutron beams have often a considerable portion of gamma rays with fast neutrons. gamma rays, as beam contaminants, can cause considerable damage to normal tissues even if such tissues do contain high boron concentrations. materials and methods: the modification of radio...

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...

When Nereis eggs are exposed to radiations from a tube of radium emanation, the walls of which absorb all the alpha-rays, the resulting physiological change is produced by rays having a coefficient of absorption of the order of 23.9 cm.(-1) This fact indicates that the physiological effect is due almost exclusively to beta-rays. The gamma-rays alone can produce the reaction. To produce equivale...

background: high density concrete is extensively used for efficient radiation attenuation in radiotherapy rooms and nuclear reactors. over the past eight years, some efficient galena-based concrete samples for shielding x or gamma rays was produced. the goal of this study was to produce a novel high density concrete against neutron and photon radiations using tourmaline and galena. materials an...

High energy gamma-ray emission has been observed above 100 MeV from at least 40 active galactic nuclei (AGN) by the EGRET instrument on the Compton Gamma Ray Observatory (CGRO), and above 300 GeV gamma rays have been detected by the Whipple observatory from two AGN. The sources detected so far are \blazars" indicating a jet origin for the gamma rays. They are seen to be variable on time scales ...

We propose generation of narrow-bandwidth GeV photons, gamma-rays, via Compton scattering of hard X-ray photons in X-ray free-electron laser oscillators [1]. The gamma-rays have a narrow-bandwidth spectrumwith a sharp peak, ∼0.1% (FWHM), due to the nature of Compton scattering in relativistic regime. Such gamma-rays will be a unique probe for studying hadron physics. In this paper, we discuss d...

We have compared the efficiency of cell-killing, DNA single-strand breakage and double-strand breakage in an Escherichia coli K-12 wild-type strain after irradiation with soft X-rays (50kVp) and hard gamma-rays (600 keV) under aerobic conditions. Irradiation with 50 kVP x-rays resulted in 1.47 times more cell killing than was observed with 137Cs gamma-rays based on a comparison of D0 values eva...