EPR Studies of Electron Irradiated Ice and Solid Hydrogen

Electron paramagnetic resonance studies of ice and H/sub 2/ irradiated in a 40-Mev electron linear accelerator are describ/sup 6/ or ice at 77 deg K and dosages of 9 x 10/sup 6/ and 18 x 10/sup 6/ rad, a strong resonance at g = 2 consisting of a doublet and other unresolved lines was observed; no H atom splitting was observed. At 4.2 deg K and various dosages (cumulative) resonances 250 gauss each side of g = 2 appeared; the same unresolved structure in the g = 2 region was found. A maximum total H atom concentration of 8 x 10/sup 6/ moles was obtained at 16 x 10/sup 6/ rad. Higher doses produced no more H atoms. For solid H/sub 2/ at 4.2 deg K only H-atom lines were observed. Modulation frequency effects at high rf levels were studied. Dose saturation study indicated H-atom concentration saturation at 7.2 x lO/sup -6/ rad; the H-atom concentration was 1.5 x 10/sup -6/ mole/g. The saturation level may have been limited by beam heating effects. (T.R.H.)