ANGULAR DISTRIBUTION OF PHOTOPROTONS FROM ALUMINUM AND TANTALUM

The study of those nuclear reactions which occur as a result of x-ray irradiation has been greatly facilitated by the increasing availability of high energy betatrons and synchrotrons. On occasion radioactivity may be induced in irradiated nuclei and in these cases it is possible to conclude that either a new element or an isotope of the bombarded nucleus has been formed. Since the nature of the radiation from many unstable nuclei is well known, a study of the type and energy of the emitted particles and the period of radioactive decay will usually suffice to determine which nucleus has been formed. In all cases the new nucleus is found to be the old nucleus with one or more neutrons and/or protons removed. The exact process whereby nuclei are transformed to different nuclei upon being exposed to x-rays has commanded considerable attention from those interested in nuclear physics.