Abstract A portable monoenergetic 24 keV neutron source based on the 124 Sb- 9 Be photoneutron reaction and an iron filter has been constructed characterized. The coincidence of energy from SbBe low interaction cross-section with (mean free path up to 29 cm) makes pure specially suited shield against gamma rays Sb decays while letting through neutrons. To increase activity thus flux, a >1 GB...

Abstract Quasi-monochromatic, high energy and highly polarized ? -ray beam sources based on Compton scattering of laser photons (LCS) relativistic electrons have developed for the last few decades as established instruments nuclear physics studies. Following an extensive photoneutron experimental campaign at LCS line NewSUBARU synchrotron radiation facility SPring8, Japan, a dedicated simulatio...

Medical linear accelerators operating above 10 MV require door shielding for neutrons in addition to photons. A criterion for choice of optimal configuration of lamination of BPE (Borated Polyethylene) and lead is not clear. Moreover, optimal configuration cannot be determined by the conventional method using an analytical formula and simple measurement. This study performs Monte Carlo simulati...

Introduction: One of the important problems of using high energy linacs is the production of photoneutrons. High energy medical linacs produce secondary neutrons. These phtoneutrons increase patient dose   Materials and Methods: In this study, the effect of plastic trays on spectrum of photoneutrons produced by 18MV linac is investigated using the MCNP4C code...

Introduction: In radiation therapy with high-energy photon beams (E > 7 MeV) neutrons are generated mainly in LINACs head thorough (γ, n) interactions. These neutrons affect the shielding requirements in radiation therapy rooms. According to the protocol TG-34, photon absorbed dose of 10Gy can cause permanent damage to the pacemaker and the dose of 2Gy can make minor changes in...

Introduction: Neutron contamination is very harmful for the patients receiving radiation therapy due to the high relative biological effect of neutrons. Medical linear accelerators head are made up of materials with high atomic numbers, and High-energy photons interaction with heavy materials can produce neutron contamination. In this study, neutron equivalent dose, neutron spe...

Introduction: One of the concerns about using of high energy photons in radiotherapy is neutron contamination production. The threshold energy of photoneutron production in most materials with high atomic number is about 7MeV. Therefore, it seems to be logical that the main components with high atomic number elements used in the LINAC head have a large contribution to the neutr...