Effect of thermal neutron irradiation at No. 2 channel of Dalat nuclear research reactor on dyed polyvinyl alcohol films.

The polyvinyl alcohol (PVA) films dyed with methylene blue were decolorised after they were irradiated in a dose range from 0.059 to 1.411 Gy by thermal neutron source at the end of the channel No. 2 of the Dalat nuclear research reactor. The thermal neutron flux at an outer position of beam line at the channel No. 2 was 1.6 × 106 neutron/cm2 s. The dyed PVA films containing boric acid could be used for improvement physical qualities of the films. Response-curves of the dyed PVA films which were irradiated by the thermal-neutron source were described by the saturated exponential function of the energy transfer model. [ABSTRACT FROM AUTHOR]