Hyperfine interactions of radioactive nuclei

Hyperfine interactions of radioactive nuclei

180 Nuclear Instruments and Methods in Physics Research 223 (l 984) 180 North-Holland, Amsterdam BOOK REVIEW Hyperfine interactions of radioactive ...

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180

Nuclear Instruments and Methods in Physics Research 223 (l 984) 180 North-Holland, Amsterdam

BOOK REVIEW

Hyperfine interactions of radioactive nuclei, ed., J. Christiansen, vol. 31 in the series Topics in current physics (Springer, Heidelberg, 1983) pp. 366, DM 84.--, ISBN 3-540-12110-2. Hyperfine interactions can be studied in great detail by a variety of methods and such experiments have contributed strongly to nuclear physics as well as to atomic and solid state physics. The present volume deals with experiments where the hyperfine interaction is studied in radioactive atoms. Such studies can be done starting from (a) radioactive nuclei with suitable life-times or (b) nuclear states which are reached by bombarding stable nuclei by beams from accelerators (with the measurements done on-line). In either case, it may be the nuclear properties extracted that are of prime interest, or the extra-nuclear effects, which can carry very detailed information about the local atomic or crystalline environment. The advantage of the radioactive detection is that excited state electromagnetic moments can be studied and that for the solid state applications the methods need only a very small number of probe atoms to give enough information. The present volume starts with hyperfine interactions in free atoms and ions (by G.D. Sprouse), where the aim is mainly to derive magnetic moments of nuclear states with life-times in the ps-region, using predictable fields from simple few-electron configurations reached by stripping the atoms. When the paramagnetic atoms are recoiled into gases instead of a vacuum it is necessary for the interpretation of the results to understand also the electronic recovery and relaxation which can be said to be another goal for the experiments. All other situations for nuclear moment determinations are collected in the chapter on nuclear physics applications (by O. H~iusser and I.S. Towner). It includes electric interactions in atoms and crystals as well as magnetic interaction in free atoms (again!) and solids where the experimenters find suitable environments for study of magnetic moments and charge distributions of

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nuclear states. Modern techniques, like high-resolution laser spectroscopy are well covered as also are methods for high spin nuclear states. The weight given to some other standard methods seems, however, a bit unbalanced, the low Z fl-emitters 12B, 12N etc. are given much space, for example, while NO-NMR in general (with 3,-detection) is hardly mentioned. A large fraction of this chapter is devoted to theoretical model predictions for various types of nuclear-excitations, made accessible by the hyperfine interaction methods. Among the numerous applications in solid state physics, the editor has first made a selection of what has been achieved in two particular fields (defects in metals and electric field gradients in non-cubic metals) and has then taken up a certain set of nuclear probes (/3-emitters and isomeric nuclei) in various fields of application. The defect studies (reviewed by E. Recknagel, G. Schatz and Th. Wichert) are one of the clear successes of the radioactive methods. A rich yield of information has been collected on defect structures seemingly inaccessible by other methods. This whole chapter is very stimulating reading. The EFG-studies (reviewed by W. Witthuhn and W. Engel) now form, after years of work in many laboratories, a reasonably closed field, where the main features can be understood. As such it is also a good example of the contributions to solid state physics from the radioactive nuclear methods. In the last chapter, finally, H. Ackermann, P. Heitjans and H.J. St6ckmann describe the astonishingly large number of different physical phenomena in solid state physics and chemistry that can be studied by j3-emitters. As a whole, the present volume contains good introductions to the field of hyperfine interactions as well as interesting reading for metal physicists and other potential users of the methods. The readers should, however, be aware that the fields of application are considerably larger than discussed here. Erik KARLSSON