Interaction of 157 nm excimer laser on pristine and radiation exposed CR39 polymer

Surface modification effect of VUV 157 nm laser on solid state nuclear track detector di-glycol carbonate (CR39), has been investigated. It covers some preliminary work on ablating pristine surface where ablation threshold obtained at this wavelength and polymer surface exposed to alpha radiation with close contact of 226Ra prior to laser treatment. Two sets of samples were prepared; the first set of samples were exposed to either 1, 5 and 10 s of radiation and the second set had samples exposed to 10 s of radiation followed by laser treatment. A chemical etching process was used to reveal micron size tracks in the CR39 polymeric detector and for comparison with ablation on the pristine surface, one sample without etching process has been prepared. Changes on the surface of the detector were observed, revealing the tracks density at different time exposure and the effects of laser treatment with and without chemically etched. Analysing modification on this polymer detector confirm that it is a useful substrate when interact with the VUV 157 nm laser.