DEVELOPMENT OF ALPHA-TRACKS AND NEUTRON-INDUCED RECOIL PROTONS IN CR-39 FOR DOSIMETRIC APPLICATIONS

In the present work, CR-39 plastic detectors have been used in alpha a nd neutron detection studies. Detectors were first treated chemically, before irradiation, for background reduction and registration efficie ncy improvement. CR-39 detectors etched pre-chemically in 6.25N NaOH s olution at 70 degrees C for 10 h were found to be necessary to minimiz e the background tracks. Alpha tracks were heated chemically and elect rochemically and the distribution of the electric spot diameter has be en studied at different values of high voltage and etching durations u sing our previously constructed electrochemical etching system. CR-39 foils were also exposed to various neutron doses from 0.17 to 4.0 rem using 5.0 Ci(241)Am-Be source. A study of recoil proton tracks in CR-3 9 detectors have been performed under different conditions of etching. The average detector sensitivity to neutron-induced proton track regi stration was found to be about 21.0+/-7% track cm(-2) mrem(-1). Result of the present work reflected the feasibility of using the CR-39 dete ctors as fast neutron dosimeter through the measurement of recoil prot on track density.