Analysis of the Contribution of Magnetic Moment Conservation to Ion Energy Transport in the GAMMA 10/PDX Divergent Field Region

We investigated the contribution of magnetic moment conservation to ion energy transport in the divergent magnetic field region, using the GAMMA 10/PDX end region to simulate scrape-off layer (SOL) plasmas in DEMO reactors. The averaged parallel energy increments (Delta E-||) were measured by performing energy analyses at two points: upstream and downstream of the GAMMA 10/PDX end region. A newly developed retarding field analyzer (RFA) was inserted upstream of the end region to perform energy analyses. Assuming that only effects of potential difference (Delta E-phi) and magnetic moment conservation (Delta E-) affect Delta E-||, the contribution of magnetic moment conservation to ion energy transport was deduced. These results suggested that Delta E- < Delta E-phi irrespective of the difference in the diamagnetism at the central cell of GAMMA 10/PDX.(c) 2023 The Japan Society of Plasma Science and Nuclear Fusion Research