The Sudbury Neutrino Observatory (SNO) is a Cerenkov detector composed of a spherical acrylic vessel filled with 1,000 metric tonness of ultra pure heavy water. It measures 12 m in diameter and is located about 2 km deep within a Canadian nickel mine. Even at this depth, cosmic rays penetrate the detector at a rate of roughly three per hour. Muons passing through the detector will interact with...

The neutron energy spectrum from the atomic bomb consisted of a range of energies from thermal to fast neutrons. Fast neutrons contribute a larger dose to the human body than lowenergy neutrons per unit flux. The evaluation of the fast neutron component has been performed based on analyses of P (>3 MeV) activity measured immediately after the Hiroshima bomb and Ni (>2 MeV), which has a much lon...

This paper investigates an analytical derivation of the distribution of the number of neutrons and photons emitted by a multiplying sample. The relationship between the statistics of the generated and detected neutrons and photons is also described. The analytical model described in this paper accounts for absorption, thus extending the model presented in previous studies. By using this new, im...

background: neutron contamination in our environment can cause harmful biological effects on human body. therefore, many efforts have been made to construct a neutron dosimeter to estimate the received dose. objective: to design a simple neutron dosimeter. methods: the primary dosimeter had 3he as a spherical thermal neutron detector encircled by paraffin 10 cm in radius. then, the paraffin sph...

The objective of this study is to demonstrate the feasibility of constructing a compact neutron detector that is sensitive to thermal and epithermal neutrons and has high rejection efficiency relative to gamma-ray background. A two-channel high-pressure He scintillation detector is considered for the detection of neutrons in coincidence mode. The detector consists of two large avalanche photodi...

Thermal neutrons/DNA replication/DNA repair The degree of inhibition of DNA replication and the level of DNA repair synthesis induced by thermal neutron irradiation was determined in human lymphoblastoid cell lines. Dose response experiments revealed that, when compared with equivalent doses of 60Co-ƒÁ-irradia tion, thermal neutrons gave rise to similar levels of inhibition of DNA replication b...

The polystyrene based scintillator SCSN38, pure polystyrene and pure polymethyl-methacrylate have been irradiated with a beam of fast neutrons and with reactor neutrons. The radiation induced permanent optical absorption coeecients after total annealing in air are compared with data for irradiations. The strong diierences might be due to the high LET of the recoil protons elastically scattered ...

In order to clarify whether the effects of neutrons on mammalian cells are qualitatively different from those of X or gamma-rays, L cells were irradiated with D-T neutrons and 180 kvp X-rays, singly or combined. From analysis of dose response curves, it is concluded that cell killing mechanism of neutrons is not the same as that of X-ray, but there is something common in part between them. RBE ...

Medical linear accelerators are one of the most widespread methods for cancer treatment. Despite their advantages, unwanted photoneutrons are produced by high energy linacs. This photoneutrons are as undesired doses to patients and a significant problem for radiation protection of the staffs and patients. Photoneutrons radiological risk must be evaluated because of their high LET and range.in o...

CALCULATIONS OF THE GIANT-DIPOLE-RESONANCE PHOTONEUTRONS USING A COUPLED EGS4-MORSE CODE J. C. Liu, W. R. Nelson, K. R. Kase and X. S. Mao Stanford Linear Accelerator Center, P. 0. Box 4349, Stanford, CA 94309 Abstract The production and transport of the photoneutrons from the giant-dipoleresonance reaction have been implemented in a coupled EGS4-MORSE code. The total neutron yield (including b...