Optical detection of ESR absorption of short-lived ion-radical pairs produced in solution by ionizing radiation

Optically detected ESR signals from short-lived (naphthalene)--(naphthalene)+ radical pairs have been observed in approximately 0.01 M naphthalene solution in squalane irradiated by fast positrons. The signal is a single line with a g-value of 2.00 and a line width of 14 G at half height. The signal to noise ratio amounts to 10 for a average radical pair concentration in the sample of 20. (Auth.)