Abstract
The effect of ionizing radiation on solid methane has previously been an area of interest in the astrophysics community. In the late 1980s this interest was further boosted by the possibility of using solid methane as a moderating medium in spallation neutron sources. Here we present test results of solid methane moderators commissioned at the ISIS neutron source, and compare them with a model based on the theory of thermal explosion. Good agreement between the moderator test data and our model suggests that the process of radiolysis defect recombination happens at two different temperature ranges: the “lower temperature” recombination process occurs at around 20 K, with the “higher temperature” process taking place between 50 and 60 K. We discuss consequences of this mechanism for the designing and operation of solid methane moderators used in advanced neutron sources. We also discuss the possible role of radiolysis defect recombination processes in cryo-volcanism on comets, and suggest an application based on this phenomenon.
| Original language | English |
|---|---|
| Pages (from-to) | 101-105 |
| Number of pages | 5 |
| Journal | Cryogenics |
| Volume | 88 |
| DOIs | |
| State | Published - Dec 2017 |
| Externally published | Yes |
Funding
The authors are grateful to J.M. Carpenter, E.P. Shabalin and S.A. Kulikov for valuable and stimulating discussions. We also would like to thank members of laboratory of spectroscopy of molecular systems in B. Verkin Institute, Kharkiv, Ukraine and particularly E.V. Savchenko for sharing their data and ideas with us and S.R. Wakefield for interest and support to the methane moderator project. We appreciate Oksana Kirichek’s original idea of possibility of triggering cryogenic eruption by thermal activation. OK was supported by the project TUMOCS. This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant No. 645660 .
Keywords
- Moderator
- Neutron radiation
- Solid methane