Advantages of passive detectors for the determination of the cosmic ray induced neutron environment.
Due to the pronounced energy dependence of the neutron quality factor, accurate assessment of the biologically relevant dose requires knowledge of the spectral neutron fluence rate. Bonner sphere spectrometers (BSSs) are the only instruments which provide a sufficient response over practically the whole energy range of the cosmic ray induced neutron component. Measurements in a 62 MeV proton beam at Paul Scherrer Institute, Switzerland, and in the CERN-EU high-energy reference field led to the assumption that conventional active devices for the detection of thermal neutrons inside the BSS, e.g. 6Lil(Eu) scintillators, also respond to charged particles when used in high-energy mixed radiation fields. The effects of these particles cannot be suppressed by amplitude discrimination and are subsequently misinterpreted as neutron radiation. In contrast, paired TLD-600 and TLD-700 thermoluminescence dosemeters allow the determination of a net thermal neutron signal.
Hajek
M
M
Atominstitute of the Austrian Universities, Vienna. mhajek@ati.ac.at
Berger
T
T
Schöner
W
W
Vana
N
N
D000337:Aerospace Medicine; D003359:Cosmic Radiation / Q000009:adverse effects; D005063:Europium; D005214:Fast Neutrons / Q000009:adverse effects; D006801:Humans; D018020:Lithium Compounds; D009502:Neutrons / Q000009:adverse effects; D011834:Radiation Monitoring / Q000295:instrumentation*; D013057:Spectrum Analysis / Q000295:instrumentation; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation
D018020:Lithium Compounds; D005063:Europium