Studies of charge separation characteristics for higher density plasma in a direct energy converter using slanted cusp magnetic field

In an advanced fusion, fusion-produced charged particles must be separated from each other for converting their kinetic energy to electricity. The CUSPDEC performs this function of separation and direct energy conversion of thermal components. This paper summarizes experimental works by using a small scale experimental device and these results as charge separation characteristics by slanted cusp magnetic field. When the incident plasma is low-density, the dependences of the separation efficiency on magnetic field strength, energy of electrons, and gradient of the field line are explained by the theory based on a single particle motion. In high density plasma, however, this theory cannot always be applied due to a self-induced field. In the experiment, as plasma density became higher, separation capability of the charged particles became lower although the efficiency of separation was improved with some extent by using slanted cusp magnetic field. The modification of the theory applicable for high density plasma and the effective factor corresponding to separation efficiency was required in the following research. (author)