Irradiation with fast neutrons at the instrument MEDAPP

Chip during test irradiation with neutrons.

Fission neutrons are neutrons which have retained their recorded kinetic energy during nuclear fission and have not slowed down. The FRM II has a secondary source (the so-called converter facility), which consists of two uranium plates. They are arranged approximately 1 m from the reactor core and irradiated with thermal neutrons in this position. Through uranium fission, fast neutrons are released and fall with a certain probability influenced by the geometric conditions into a horizontal beam tube that guides them to their destination.

The beam tube ends at the instrument MEDAPP. MEDAPP facilitates the irradiation of tumour patients and a number of other experiments; for example, for physical and biological dosimetry, studies of material resistance to neutron irradiation (functional life of semiconductors, devices in aerospace) and non-destructive materials testing. The flux density of fast neutrons at the irradiation position is approximately 3,2 x 108 cm​​-2s-1.