Fast current ramp experiments on TFTR

Abstract

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Profile consistency on TFTR

“…The study of electron temperature profile shapes, available from the multipoint Thomson scattering, ECE radiometer, and Michelson interferometer diagnostics, on TFTR has supported initial impressions that profile shapes are indeed more constant than known constraints can account for [4][5][6][7]. The shape of the profile outside approximately 0.4a (outside the sawtooth reconnection region in low q discharges) is found to be nearly invariant over a wide range of density, edge q and neutral beam heating power.…”

“…Observations on the consistency of the electron temperature profile shape (the temperature profile can vary considerably in magnitude, but it is the shape which is being studied here) have been reported on many tokamaks (TFTR, Alcator, ASDEX, JET, T-10, TEXT, etc.) [2][3][4][5][6][7][8][9][10][11][12]. In investigations of profile consistency, the profile shapes have traditionally been quantified in terms of the profile peaking parameter, T c (0)/(T e ).…”

“…The anomalous influx counteracts the diffusion and anomalous outflow and can give a proper explanation of the relatively peaked density profiles of tokamak devices. This paper discusses a method of inducing the influx by using a specially structured asymmetric ripple [5]. The induced influx will also counteract the diffusion outflow like anomalous influx in a controlled fashion.…”

High power ICRF heating experiments on the JIPP T-IIU tokamak

“…It has been observed that even when the heat deposition profile is widely changed in NBI [27][28][29] or ECH [30] heating experiments, the electron temperature profile does not change at all and only responds to the safety factor q(a) [27,31], while the density profile can be controlled by using pellet injection [32]. Theoretically, some explanations for this so-called profile consistency have been presented in the framework of the MHD (e.g.…”