Nada Tawfiq F and Mohammed Neamah M
The effect (He-Ne) laser on the registration properties of alpha particle tracks on CR-39 track detector was studied. CR-39 detectors were exposed to different powers (1, 5 and 10 mW) of He-Ne laser beam at different times (5, 10 and 15 min) and then irradiated to alpha-particles from 226Ra source (laser+α). Track diameters (D), track density (ρ) were determined using 6.25 N NaOH at 60°C. Bulk etching rate (VB), track etching rate (VT), critical angle (Ó¨c), etching efficiency (η), Sensitivity (S), etching ratio rate (V) were calculated. It’s found increase in the values of (D, ρ, VB, VT and Ó¨c) with increase in the exposure times of laser at each power case, and decrease in the values of (η, S and V) with increase in the exposure time of laser at 1 mw power, while increasing within increase of exposed times of laser at (5 and 10 mW). The optimum etching time of CR-39 detectors was (4 h) with NaOH etchant solation and 6.25 at temperature 60oC.