RRFM 2009 Transactions - European Nuclear Society

USE OF FISSION RADIATION IN LIFE SCIENCES AND MATERIALS
CHARACTERISATION
F.M. WAGNER, B. LOEPER-KABASAKAL, H. BREITKREUTZ, W. PETRY
Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München
85747 Garching – Germany
T. BÜCHERL
Institut für Radiochemie, Technische Universität München
85747 Garching – Germany
ABSTRACT
At FRM II, a pair of uranium plates can be driven in front of beam tube SR10 where
they become the source of an unmoderated fission neutron beam. Without
converter plates, the thermal flux can be used. For the application of fast neutrons,
the accompanying gamma radiation is normally reduced by a set of lead filters. The
related standard neutron beam has essentially a Watt spectrum with mean energy
1.9 MeV. Clinical and biological applications use the high linear energy transfer of
fission neutrons. Human tumours suitable for neutron treatment are situated near
to the surface, e.g., head and neck tumours, lymph node or skin metastases from
various cancer diseases, and chest wall metastases of breast cancer. Fast
neutrons are also used for radiography and tomography of specimen consisting of
metal and/or organic substances. Especially hydrogen generates a good contrast.
Further applications deal with the radiation hardness of electronic components.
1. Introduction
Within the moderator tank of FRM II, a pair of highly enriched uranium plates (499 g 235 U)
can be moved in front of the beam tube SR10 (Fig. 1,2).
Fig 1: Horizontal section of the irradiation facility:
1 Compact reactor core; 2 D 2 O moderator tank;
3 Vertically movable converter plates in a shaft;
4 Light water zone; 5 He-filled beam tube SR10;
6 Biological shield; 7 Four revolving shutters;
8 Position for irradiations with thermal neutrons;
9 Filter bench; 10 Multi leaf collimator
Fig 2: Vertical section of the
reactor pool with converter facility
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