Radical formation in the radiolysis of solid adipic acid by γ-rays and heavy ions

Abstract

Radical formation in solid adipic acid irradiated with γ-rays, 175 MeV Ar8+, 220 MeV C5+, and 350 MeV Ne8+ ions was studied by ESR method. The radical yield for the ion irradiations (number of radicals per incident ion) is constant below a critical fluence of about 5 × 1010ions cm−2 for the Ar ions, 1011 ions cm−2 for the C and the Ne ions. Above the critical fluence, the yield decreases with increasing ion fluence. The G-value of the radical formation was obtained from the constant yield at the low fluences: 5.6 for the C ion, 2.3 for the Ne ion, and 0.65 for the Ar ion. The G-value for the Ar ion is about 110 of the value of 6.3 for γ-irradiation. The larger effect of radiation quality for adipic acid than the effect for alanine is ascribed to the difference in the dose-yield relationship of the radical formations.