Probe edge measurements in JET X-point plasmas for various heating and plasma conditions

Abstract

An edge database is presented for divertor discharges in JET with various configurations: single null upper/lower (SNU/SNL), double null (DN), Δ B drift towards or away from the target and various divertor target materials (Be and C). We present the scaling of the scrape-off layer (SOL) parameters (i.e. density, temperature and their radial profiles) with main plasma parameters for divertor discharges with: I p =3.2 MA, 409-1 and B t =2.2–3.4 T. Results are presented for ohmic, L-Mode and H-mode discharges with additional heating (NBI and ICRH) up to 10 MW. The parameters were measured in the main SOL and at the divertor plates. A comparison is made for discharges when gas puffing was used either at the midplane or at the X-point. The results are compared with similar scalings obtained in limiter plasmas and with the predictions by simple SOL models.