Comparison of neutron spectrum measurement methods used for the epithermal beam of the LVR-15 research reactor

The LVR-15 research reactor's horizontal channel with its epithermal neutron beam is used mainly for boron neutron capture therapy. Neutrons from the reactor core pass through a special filter before the collimator and the beam outlet. Neutron fluence and spectrum are the basic characteristics of an epithermal neutron beam. Three methods used to measure the beam's neutron spectrum are described: the activation method, a Bonner sphere spectrometer with gold activation detectors and a Bonner sphere spectrometer with LiI(Eu) scintillation detector. Examples of results are compared and discussed. ► Neutron fluence and spectrum were measured on epithermal neutron beam. ► Three measurement methods are described. ► Examples of results are compared and discussed.