2672
D. R. Rosseinsky and I. A. Dorrity
to the e< concentration in experiments where the latter reached a plateau at low doses. Likewise, the re-irradiation tests do not prove that radiation-produced olefins are unimportant since the olefin concentration in the melted and refrozen samples would be much lower than the local olefin concentration in the radiation-produced spurs. Thus the reasons for discarding excited olefins as the source of the observed luminescence do not now appear compelling. It has been reportedlo" that the presence of mole fraction of olefins or diolefins in alkane glasses greatly increases the luminescence observed after y irradiation and, in other work, that mole fraction of 2-methyl1-pentene in 3MP glass increased the lumine~cence.~~ The absorption spectra (So SI) of various olefins show red limits near 200 nm1.l5The 230-nm luminescence of yirradiated 3MP is in the correct energy region to represent olefin fluorescence and has a lifetime
