Neutron Dosimetry for an 18 MV Medical Linear Accelerator

Electron Linear Accelerators (linacs) used in Radiotherapy treatments produce undesired photoneutrons when they are operated at energies above 8 MeV (electron mode) and at energies above 6 MV (photon mode). These neutrons contaminate the therapeutic beam and increase both in and out of field dose to patients. Dosimetric characterisations of these high energy beams, as well as investigations about neutron contamination are highly important for medical physicists working in the hospital. Primarily the need is to detect these neutrons and be able to estimate the neutron dose equivalent.