Radical formation in lithium trifluoromethane-sulfonate for ESR dosimetry

Lithium trifluoromethane-sulfonate (Li-TFMS:CF3SO3Li) irradiated by gamma-rays showed an electron spin resonance (ESR) powder spectrum having the rhombic g-factor of g(xx)= 2.0259 +/- 0.0005, g(yy)= 2.0112 +/- 0.0005 and g(zz)= 2.0025 +/- 0.0005 and a triplet hyperfine coupling constant of A(xx)/g beta= 0.8 +/- 0.15 mT. A(yy) and A(zz) are not obtained because of the broadened spectrum. The energy levels, g-factor, A(xx)/g beta and Optical absorption spectrum of several conceivable radicals such as (CF2SO3Li)-F-., CF3-S-O-. and CF3-S-O-O-. have been calculated by softwares MOPAC-V2 and Gaussian-98 based on ROHF (Restricted Hatree-Fock for open shell molecule). The most probable radical was ascribed to CF3-SO. from both calculated and experimental results. The response to gamma-ray dose and the thermal stability have been studied in addition to the effect of UV illumination for possible use of the signal intensity in ESR dosimetry. The obtained number of free radicals per 100 eV (G-value) was 1.23 +/- 0.40.