Double Focusing Mass Spectrometers of Second Order

Abstract

The resolution of the on-line mass spectrograph is normally several hundred and this is sufficient to separate nuclei having different mass number A. If the nuclei to be analyzed have the same A but different charge number Z, they can not be separated by this amount of resolution. However, the complete separation of nuclei (both A and Z) can be possible if the resolution is raised by about hundred times, that is, up to several ten thousands. Fig. 1 shows an example of the estimated mass excess curve of nuclei with the same A plotted as a function of Z. The length of the bars in the figure corresponds to the separable mass differences for the resolution indicated. It is seen that the resolving power of about 30000 would be sufficient to resolve all nuclei far from the valley of beta-stability. Besides, the direct mass measurement of short lived nuclei would be possible with such a high resolution mass spectrograph. The determination of masses of nuclei far from beta-stability is also a very interesting and important problem.