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-offlayer (SOL) plasmas in DEMO reactors. The averaged parallel energy increments (∆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 (∆Eϕ) and magnetic moment conservation (∆E⟨µ⟩) affect ∆E∥, the contribution of magnetic moment conservation to ion energy transport was deduced. These results suggested that ∆E⟨µ⟩< ∆Eϕ irrespective of the difference in the diamagnetism at the central cell of GAMMA 10/PDX.