Atomic hydrogen radial flux dependence on plasma parameters in TEXTOR

Radial flux measurements of atomic hydrogen leaving the TEXTOR plasma have been carried out using permeation through a heated metal membrane. The probe response time is 210 ms. The membrane is typically located 40-50 cm radially beyond the plasma edge. Impurity deposition on the upstream face is small and does not significantly change the permeation performance of the membrane. The dependence of the atomic hydrogen flux on plasma position, plasma current and line-averaged electron density has been investigated during a two week campaign. The key observations are: neutral flux increases linearly with increasing line-averaged electron density; and, the neutral flux does not depend on plasma current in an ohmically heated plasma for currents up to 340 kA. (orig.)