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 (∆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 (∆E_ϕ) 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> < ∆E_ϕ irrespective of the difference in the diamagnetism at the central cell of GAMMA 10/PDX. (author)