Irradiation effects of X-rays (45 min and 90 min) on track etch parameters of Lexan polycarbonate detectors have been studied with respect to structural behavior using Fourier transform infrared spectroscopy (FTIR) spectroscopy. Pre-exposure and post-exposure of X-rays bring significant changes in track etch parameters (bulk etch rate (BER) and track etch rate (TER)) of Lexan polycarbonate detectors at 55[Formula: see text]C to 75[Formula: see text]C. The energy carried by X-rays results in hardening due to cross-linkage and softening due to chain scission of Lexan polycarbonate detectors. BERs and TERs follow Arrhenius equations, and slopes of graph reveal information about activation energy of BERs and TERs. Bulk activation energies calculated are found to be 0.91 eV (unexposed), 0.94 eV (pre-exposed 45 min), 0.96 eV (pre-exposed 90 min), 0.88 eV (post-exposed 45 min) and 0.86 eV (post-exposed 90 min) and are also found to be in agreement with available literature. Track activation energies (TAEs) calculated are found to be 0.74 eV (unexposed), 0.75 eV (pre-exposed 45 min), 0.77 eV (pre-exposed 90 min), 0.74 eV (post-exposed 45 min) and 0.73 eV (post-exposed 90 min). Post-exposure of X-rays for 90 min on Lexan polycarbonate detectors results in enhancement of sensitivity and recorded highest (12.72) at 65[Formula: see text]C. The critical angle of Lexan polycarbonate detectors is also affected by post-exposure of X-rays for 90 min and found maximum (38.59[Formula: see text] at 75[Formula: see text]C. FTIR spectra confirm cross-linkage in Lexan polycarbonate detector during 3 h exposure of fission fragments (FFs) of [Formula: see text]Cf as compared to 2 h exposure.