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...

Radiotherapy represents the most widely spread technique to control and treat cancer. To increase the treatment efficiency, high energy linacs are used. However, applying high energy photon beams leads to a non-negligible dose of neutrons contaminating therapeutic beams. In addition, using conventional linacs necessitates applying wedge filters in some clinical conditions. However, there is not...

PERSONNEL HAZARDS FROM MEDICAL ELECTRON ACCELERATOR PHOTONEUTRONS" R. C. McCall, T. M. Jenkins, R. A. Shore and P. D. LaRiviere+ Stanford Linear Accelerator Center, CA, U.S.A. and Varian Associates? INTRODUCTION For medical accelerators, neutron penetration through the room entry door is the major personnel hazard. Most therapy accelerator rooms are designed with at least a rudimentary maze to ...

When operating linear accelerators of clinical use at energies above 8 MeV, neutrons are produced when either electron or photon configurations are used [1]. This is mainly due to the interactions of photons and electrons of such energies with the high-Zmaterials present in the accelerator head (target, scattering foils, collimators, etc.) [22]. Because of their high relative biological effecti...

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...

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...

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...

It is necessary to consider the effect of photoneutrons produced by photonuclear reactions in shielding calculation a medical linac room with incident electron greater than 10 MeV. For copper and tungsten used as target materials linac, we compared experimental data evaluated four reaction files photoneutron production cross sections. We also calculated results using on angular distributions em...