Dosimetry studies have been carried out at thermal and epithermal columns of LVR-
15 research reactor for investigating the spatial distribution of gamma dose, fast
neutron dose and thermal neutron fluence. Two different dosimetry methods, both
based on solid state detectors, have been studied and applied and the accuracy and
consistency of the results have been inspected. One method is based on Fricke gel
dosimeters that are dilute water solutions and have good tissue equivalence for
neutrons and also for all the secondary radiations produced by neutron interactions in
tissue or water phantoms. Fricke gel dosimeters give the possibility of separating the
various dose contributions, i.e. the gamma dose, the fast neutron dose and the dose due
to charged particles generated during thermal neutron reactions by isotopes having
high cross section, like 10B. From this last dose, thermal neutron fluence can be
obtained by means of the kerma factor. The second method is based on
thermoluminescence dosimeters. In particular, the developed method draw advantage
from the different heights of the peaks of the glow curve of such phosphors when
irradiated with photons or with thermal neutrons. The results show that satisfactory
results can be obtained with simple methods, in spite of the complexity of the subject.
However, the more suitable dosimeters and principally their utilization and analysis
modalities are different for the various neutron beams, mainly depending on the
relative intensities of the three components of the neutron field, in particular are
different for thermal and epithermal columns
