SUMMARY

Various aspects of hot atom chemistry are described, reviewing it from fundamentals to applications. In gas, liquid and solid systems recoil atom reactions show characteristic features. Chemical behavior of implanted atoms that is specific to them and somewhat different from that of ordinary recoil atoms is also described. Examples of radioisotope enrichment are included.

1. INTRODUCTION

It is usually considered that hot atom chemistry deals with chemical effects of nuclear transformations which result in formation of hot atoms with high kinetic energy or high electric charge. However, in some cases hot atoms with high energy can be generated by non-nuclear means (photochemical method, beam acceleration, etc.). These non-nuclear hot atoms are included in up-to-date hot atom chemistry concepts in this chapter.

The recoil phenomenon which is intimately related to hot atom chemistry was first observed by H.Brooks (1904) in 1904 at the McGill University (TABLE 1). She noticed severe contamination with radioactivity of RaB ^[1] and C in the ionization chamber she used. In 1905, Rutherford (1951) (Nobel Prize 1908) who supervised her work concluded that the phenomenon observed by her was based on the recoil energy of the residual nucleus introduced by alpha particle emission on the nuclear disintegration of RaA (in other words, implantation in the wall material occurred). Then the technique using nuclear recoil was successfully employed by Hahn (1909) (Nobel...