Performance of CR-39 ® with addition of DOP (dioctylphthalate) for fast neutron dosimetry

Abstract

The ENEA fast neutron dosemeter is based on a planar poly allyl diglicol carbonate (PADC) placed in a polyethylene holder. The present paper reports the results of an experimental study of a CR-39 ® material with the addition of 0.1% of dioctylphthalate (DOP) produced by the Italian company Intercast Europe S.p.A. The etching procedure is: pre-etching with 40% KOH water solution 6.25 N and 60% ethyl alcohol at 70°C followed by 12 h of etching in 6.25 N KOH water solution. For the energy dependence of response, dosemeters have been irradiated with neutron sources ( 241 Am –Be, 252 Cf , Pu–Li) and 14.9 MeV monoenergetic neutrons. The dosimetric performance of the material for fast neutrons is expressed in terms of sensitivity, background value, lowest detectable dose and energy dependence of response. Moreover, the results of a quality acceptance test of the material, performed on 11 sheets ( 980×980 mm 2 , 1.4 mm thick) of the same production batch, are given. Therefore, the homogeneity of the neutron sensitivity and of the background signal within a sheet and the whole batch is considered. The results are compared with the acceptance test outcome for a CR39 standard material batch.