FTU results with a liquid lithium limiter

Since the end of 2005 most of the plasma?wall interaction experiments on FTU have been focused on the possible use of liquid lithium as the plasma facing material. Liquid lithium limiter is an active method to deposit, during the plasma discharge, a lithium film on the walls with prolonged beneficial effects. Reliable operation with very clean plasmas, very low wall particle recycling, spontaneous peaking of the density profile for line-averaged density values 1.0\times 10^{20}\,{\rm m}^{-3} SRC=http://ej.iop.org/images/0029-5515/51/7/073006/nf381122in001.gif/> have been obtained. These results have allowed us to extend the density limit to the highest value so far obtained ( at Ip = 0.7?MA and BT = 7.1?T, qa = 5.0, by gas puffing only) and to increase the energy confinement time by almost 50% with respect to the average value of 50?ms of the old ohmic FTU database. An accurate analysis of these plasmas has been carried out by means of a gyrokinetic code to establish the role of collisionality and density gradients on the observed phenomenology.

[1]  Bruce Lipschultz,et al.  Review of MARFE phenomena in tokamaks , 1987 .

[2]  R. Budny,et al.  Enhanced performance of deuterium–tritium‐fueled supershots using extensive lithium conditioning in the Tokamak Fusion Test Reactor , 1995 .

[3]  S. Mirnov,et al.  Preliminary analysis on a liquid lithium limiter in capillary porous system (CPS) configuration in view of a litization experiment on FTU tokamak , 2005 .

[4]  E. Giovannozzi,et al.  Review of FTU results with the liquid lithium limiter , 2010 .

[5]  M. L. Apicella,et al.  First experiments with lithium limiter on FTU , 2007 .

[6]  G. Mazzitelli,et al.  Chapter 1: The FTU Program , 2004 .

[7]  M. L. Apicella,et al.  Chapter 10: FTU Operation , 2004 .

[8]  C. Bourdelle,et al.  Effects of high density peaking and high collisionality on the stabilization of the electrostatic turbulence in the Frascati Tokamak Upgrade , 2004 .

[9]  C. Bourdelle,et al.  Confinement and turbulence study in the Frascati Tokamak Upgrade high field and high density plasmas , 2006 .

[10]  R. Budny,et al.  Enhancement of Tokamak Fusion Test Reactor performance by lithium conditioning , 1996 .

[11]  M. L. Apicella,et al.  Lithium capillary porous system behavior as PFM in FTU tokamak experiments , 2009 .

[12]  S. Mirnov,et al.  Experiments with lithium limiter on T-11M tokamak and applications of the lithium capillary-pore system in future fusion reactor devices , 2006 .

[13]  F. J. Casson,et al.  The nonlinear gyro-kinetic flux tube code GKW , 2009, Comput. Phys. Commun..

[14]  G. Mazzitelli,et al.  Heat loads on FTU liquid lithium limiter , 2011 .

[15]  E. Giovannozzi,et al.  High density operation on Frascati Tokamak Upgrade , 1996 .

[16]  M. L. Apicella,et al.  Edge properties with the liquid lithium limiter in FTU—experiment and transport modelling , 2007 .

[17]  M. L. Apicella,et al.  Peaked density profiles and MHD activity on FTU in lithium dominated discharges , 2010 .