This research reveals the possibility of altering the structural, surface, fluorescence, and optical characteristics of CR-39 polymer detector by the effect of Ultrasonic frequency (UF) plasma argon gas. The samples were exposed to the plasma at different times ranging from 20 min to 100 min. Fourier Transform Infrared (FTIR) Spectroscopy, contact angle goniometer, surface roughness tester, photoluminescence spectroscopy, and UV/Vis Spectroscopy have been applied to analyze alterations of CR-39 polymeric films to understand the mechanisms of produced alterations by plasma treatment. The obtained FTIR spectra demonstrated that the plasma treatment-related changes in the absorption bands are associated with the treatment time, leading to two critical processes, degradation, and crosslinking. In comparison to the untreated surface, the surface wettability results showed that the liquids' contact angle decreased after treatment with a UF plasma source. This modification in the treated surface denotes an increase in polar groups there, which causes the surface to change to a hydrophilic state. The surface roughness of the samples following plasma treatment showed that UF plasma significantly changed the surface morphology of the CR-39 films. After plasma exposure, considerable emission bands were produced, and the photoemission spectra of the treated film showed a fluorescence response. As the exposure time increased, more fluorescence peaks were formed due to the increase in defects. The UV/Vis spectra showed that the modified films' absorption edges were moved toward lower photon energies. This resulted in a smaller optical energy gap, which led to an expansion of the carbon cluster. Additionally, the untreated sample's transmittance dropped from 92% to 47% for the treated film. In contrast to untreated films, a change in optical characteristics was seen in treated films.