Measurement of Spatial Distributions of Fusion Reactions in an Inertial Electrostatic Confinement Fusion Device Driven by a Ring-Shaped Magnetron Ion Source

摘要

In an inertial electrostatic confinement (IEC) fusion device, the so-called 'beam-beam' reactions are preferable as their fusion rate shows I~2-dependence. In previous experiments with a newly developed-IEC device driven by a ring-shaped ion source at low pressure (several mPa D2), we observed I~2-dependence of neutron production rate for the first time in the world. It is necessary to clarify what brought this I~2-dependence. Measurement of spatial distribution of proton production by DD fusion reactions should be an effective means of determining the contribution of beam—beam reactions. With this new low pressure IEC, however, the detector should be nearer the IEC center in order to detect ample proton count rate, limiting X-ray flux on the detector by the collimator. Additionally, spatial resolution is required to be higher than the previous system to distinguish the central gridded cathode space from the cathode surface. We have designed a new measurement system. The spatial resolution was expected to be high enough. New setup has been ready, and experiments in the new IEC will be done very soon.