The measurement with the Medipix2 detector ad the RW3 moderator in the neutron field of the Clinac 2100 linear accelerator

Detection of neutrons in radiotherapy is important to determine the radiation exposure of the patient. Today, the most commonly are used TLD detectors for routine determination of patient dose. These detectors are not accurate. Other applications of Bonner spheres, which is positioned as proportional counter. The detection of neutrons is also possible with Medipix2 detector. Measured results show that using Medipix2 detectors can detect fast neutrons. Fast neutrons are slowed down in the moderator RW3 to thermal neutrons. These neutrons are converted by the LiF₆ to charged particles, which are registered by Medipix2 detector. Results of our measurements show the greatest efficiency is achieved with RW3 moderator thickness 40 mm. In the future we plan to place the detector Medipix2 Bonner sphere. This requires a reduction of ambient electronic detector. On this issue has been working intensively. Then we compared the individual responses to detected neutrons which are moderated by Bonner spheres with no available relative dependencies. This principle of neutron detection with detector Medipix2 will be used for monitoring the neutron field in the radiotherapy clinic at The University Hospital Bulovka as part of radiation protection of staff and patients. (authors)