XA0203 194 MAGNETIC CONFINEMENT EXPERIMENTS 59

EX/P4-19 Liquid Lithium Limiter Effects on Tokamak Plasmas and Plasma-Liquid Surface Interactions R. Kaita, Princeton Plasma Physics Laboratory, Princeton (NJ), USA Contact: kaita~ppplgov Abstract: We present the results from the first experiments with a large area liquid lithium limiter in a magnetic fusion device, and its effect on improving plasma performance by reducing particle recycling. Using large area liquid metal surfaces in any major fusion device is unlikely before a test on a smaller scale. This has motivated its demonstration in the CDX-U spherical torus with a unique, fully toroidal lithium limiter. The highest current discharges were obtained with a liquid lithium limiter. There was a reduction in recycling, as indicated by a significant decrease in the deuterium-alpha emission and oxygen radiation. How these results might extrapolate to reactors is suggested in recycling/retention experiments with liquid lithium surfaces under high-flux deuterium and helium plasma bombardment in PISCES- B. Data on deuterium atoms retained in liquid lithium indicate retention of all incident ions until full volumetric conversion to lithium deuteride. The PISCES-B results also show a material loss mechanism that lowers the maximum operating temperature compared to that for the liquid surface equilibrium vapor pressure. This may restrict the lithium temperature in reactors.

EX/P4-20 Overview and Initial Results of the ETE Spherical Tokamak XA02031 95 L.A. Berni, Instituto Nacional de Pesquisas Espaciais (INPE), Sho Jos6 dos Campos, Brazil Contact: berniglpasma.inpe.brw Abstract: The ETE (Experimento Tokamak Esf6rico) is a small size aspect-ratio machine with major and minor radius of 30 cm and 20 cmjrespectively. The vessel was made of Inconel and provides reasonable good access for plasma diagnostics through 58 Conflat ports. The first plasma was obtained at the end of 2000 and presently plasma currents of 45 kA lasting for about 4 ms are routinely obtained. Achievement of the designed parameters (plasma current up to 200 kA lasting for about 10 ins) for the first phase of operation is expected by the end of 2002, by increasing the energy of the capacitor banks and the operational voltage. A set of basic diagnostic for plasma characterization is already installed. This paper presents some details of the ETE project and the initial characterization of the plasma as well as the future plans. This work was supported by FAPESP, FINEP, and CNPq.

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EX/P4-21 . Recent Experimental Results of HL-1M and Progress of HL-2A Project Yong Liu, Southwestern Institute of Phyics, Chengdu, Sichuan, China Contact:. iuyongglswip.ac. cn Abstract: Recent experimental results of HL-1M tokamak and progress of HL-2A project are presented. Strong fishbone instability was observed during off-axis ECR.H. This is first observation of the fishbone instability purely driven by energetic electrons produced by ECRH. The MBI was first proposed and demonstrated on HL-1M. Recently new results of MBI experiment were obtained by increasing the pressure of gas. A stair-shape density increment was obtained with high-pressure multi-pulse MBI just like the density evolution behavior during the multi-pellet injection. It is shown that injected particles could penetrated into the core region of the plasma. HL-2A is a divertor tokamak in construction at SWIP based on original ASDEX main components. Mission of HL-2A Project is to exploring physics issues involved in advanced tokamak. For first phase, the divertor (edge plasma) and confinement researches will be emphasized. The major parameters of HL-2A are: R = 1.64 m., a = 0.4 m, Bt = 2.8 T, p = 0.48 MA. The main parameters and characteristics of subsystems such as power supply, pumping, diagnostics and auxiliary heating are presented in the paper. The first plasma of HL-2A is expected at the end of 2002.