D-D and D-/sup 3/He proton measurements of cylindrical radially convergent beam fusion

Summary form only given. Radially convergent beam fusion (RCBF) device is a compact fusion neutron/proton source with extremely simple configuration, high controllability, and hence high safety. It has been mainly studied for practical use as a portable neutron source for various applications such as landmine detection, and the results of previous studies indicate that the RCBF device has a high potential as a neutron source. On the other hand, however, the RCBF device as a proton source has not been investigated sufficiently. In this study, not only neutrons but also protons generated by D-D and D-³He reactions in a cylindrical RCBF device were measured for practical proton source. In order to detect protons, a solid-state detector (SSD) was used. However, there is a difficulty in applying the SSD to the RCBF device. The SSD can not discriminate protons from X-rays, which are produced simultaneously in the RCBF device. In addition, it is difficult to stop the X-rays with a metallic foil filter because of its high transmittance. Therefore, a new proton counting system based on magnetic deflection was designed and used to eliminate the X-rays. The system has three magnetic deflectors, which consist of a pair of neodymium magnets. The SSD position in this system was determined by a calculation of the deflected proton trajectory. At first, the cylindrical RCBF device was operated using only deuterium gas. Generated D-D protons of 3.03 MeV were measured with and without this proton counting system, and the count rate was compared with that of D-D neutrons. Then D-³He protons of 14.7 MeV were counted feeding not only deuterium gas but also helium-3 gas. By comparing D-³He proton and D-D neutron count rates, the optimal ratio of helium-3 gas to deuterium gas was obtained