Tritium target preparation

Tritium targets are normally prepared by allowing tritium gas to be absorbed into a thin layer of titanium on a suitable base such as copper. Using this reaction, miniature accelerator tubes have been designed which are small enough to be completely inserted into a reactor. These devices can be operated in the pulsed mode the rate of decay of the neutron flux following a rapid injection of neutrons into the reactor can be measured and used to obtain information on parameters such as the effectiveness of the reactor control system. 

Tritium is prepared in a Li(n,a) H-reaction by irradiation of appropriate Iithium-6-enriched compounds (e.g. LiF or alloys (Li-Al, Li-Mg) with a high flux of neutrons in a nuclear reactor. Some of the tritium evolves as H2 gas from the target through recoil during the generation process, and the rest is retained in the solid from which it is liberated by chemical methods. 

Lithium Oxide. Lithium oxide [12057-24-8], Li20, can be prepared by heating very pure lithium hydroxide to about 800°C under vacuum or by thermal decomposition of the peroxide (67). Lithium oxide is very reactive with carbon dioxide or water. It has been considered as a potential high temperature neutron target for tritium production (68). 

Introduction of isotopes by exchange (direct replacement) is the most straightforward method of preparation of labeled targets from their unlabeled analogs. This approach is used mainly in tritium chemistry, where its advantage of simplicity is, however, offset by wide variation in (and sometimes by the unpredictability of) the extent and position of labeling. Therefore substrate-specific optimization might be... 

In practice, more than one approach might be applicable to the labeling of a given target. In order to identify the most effective strategy, a number of issues, peculiar to the preparation of compounds labeled with tritium or carbon-14, warrant consideration. 

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