Table 2.
Comparison between the UV/EUV Photo-Induced Half-Lives of Pyrimidine in Pure H2O Ice When Subjected to the 0th Order Light, the He i Line, and the He ii Line
| Experiment/UV source | Photon energy (eV) | Half-lives (min) |
|---|---|---|
| Synchrotron 0th order light | 4.1–49.6 | 22 |
| Synchrotron He i line | 21.2 | 47 |
| Synchrotron He ii line | 40.8 | 35 |
| H2-discharge lampa | 6.9–11.3 | 38 |
| Pyrimidine in argon (1:750) with H2-discharge lampb | 6.9–11.3 | 0.93 |
These half-lives are compared with that of an H2O:pyrimidine=20:1 ice mixture irradiated with an H2-discharge UV lamp (Nuevo et al., 2009) and with that of pyrimidine in an argon matrix (Peeters et al., 2005) with a similar H2-discharge lamp.
a
Data from Nuevo et al. (2009).
b
Data from Peeters et al. (2005).