β Scribed by O. Kofoed-Hansen
No coin nor oath required. For personal study only.
of r-recoil experiments in which an energy determination has been attempted. Experiments where merely recoil-efficiencies have been determined 2-1) shall not be considered. The investigations will be divided into two classes .the first of which comprises all experimentswith K-capture processes and the other one comprises experiments on r-decay processes. At the same time the experiments will be divided into two other groups according to the nature of the radioactive material applied. One group comprises all experiments with m0no-atomic gases and the other group comprises the rest, i.e., either solid radioactivities or radioactive atoms forming parts of molecules. Whereas the second subdivision o~ the material is chosen for experimental reasons which will become evident from the following discussion, the first subdivision into K-capture processes and r-decay processes has been introduced since K-capture gives rise to nearly monoenergetic recoils and demonstrates most clearly the existence of the neutrino while the more composite phenomena associated with recoils from r-decay should allow a determination of the angular correlation between the directions of emission of the r-particle and the neutrino and thus give some information on the coupling in r-decay 6-11). Unfortunately no very precise experimental results have been obtained so far and therefore also new experiments shall be mentioned which are not yet completed but from which more precise data may be expected. A detailed discussion of gener.al experimental questions and of their interpretation will be given but the many different experimental procedures will only be summarized very briefly. O Results J. S. Allen suggested by K. C. Wang
π SIMILAR VOLUMES
The standard Big Bang cosmology predicts that the universe is abundantly populated with neutrinos. As expected there are at least 114 neutrinos per cubic centimeter averaged over the whole space. Like the cosmic background radiation the cosmic neutrinos at present posses a very small kinetic energy