Density behaviour and particle influxes during ICRF heating of limiter discharges in JET

During ICRF heating in JET, the neutral influxes generally increase. The magnitude of influxes and also the density increase, are proportional to the radio frequency (r.f.) power. The important parameter is the number of neutral atoms available for desorption from the wall and limiters. The global particle confinement time, which is the ratio of the electron content to the total influxes, decreases with the r.f. power input. At the onset of r.f. power a rapid desorption occurs. The scaling of the wall and limiter fluxes with plasma current and r.f. power, indicate that the density and temperature profiles in the scrape-off layer behave as expected from the simple diffusive models of the plasma boundary. (author)