No abstract

Electronic components must be tested to allow for safe and reliable missions in radiation environments. The METU Defocusing Beamline (METU-DBL) was installed in the R&D room at the Particle Accelerator Facility (PAF) of Turkey Energy, Nuclear and Mining Research Institute (TENMRI) to perform proton irradiation tests for these electronic components in accordance with the ESA (European Space Agency) ESCC (European Space Components Coordination) No:25100 standard. METU-DBL uses beam elements such as quadrupole magnets and collimators to enlarge the beam and decrease the flux respectively for the specifications of the standard. A pretest setup was constructed and this system was operated for a total of 17 hours for three months before the METU-DBL final design was assembled. The first protective collimator is made of stainless steel 316L and was used during the period of pretests. As a result of these irradiations, the emerged radioisotopes in the collimator were observed and measured insitu with a NaI detector. These measurements were compared with the FLUKA simulations 120 days after the last irradiation. Among fourteen radioisotopes, only six of them with activity above 1.0×101 Bq/cm3 were matched.

No abstract

Neutron shielding is of utmost importance in radiation environments such as nuclear reactors and particle accelerators and in fields such as health physics. In this work, the percentages of neutrons stopped by shields comprising of boron minerals (HDPE/B2O3, Epoxy/Priceite, Epoxy/Colemanite, Epoxy/Kernite) in their composition against neutron radiation of different energies is investigated using two separate MC simulations. Different layer combinations of epoxy based borated shielding materials with HDPE sheets were then simulated to find the optimum shielding configuration. In addition, radioactivation studies were carried out for these designs. The most suitable design was found to be the layered setup of the HDPE sheet and the epoxy/colemanite composite sheet for mixed neutron energies (