http://www.fusion.ucla.edu/abdou/abdou%20publications/2004/FEDv72n1-3p35-62.pdf

Exploratory studies of flowing liquid metal divertor options for fusion-relevant magnetic fields in the MTOR facility

Abstract In this paper, we present a brief historic overview of the research on dust in fusion devices with carbon plasma-facing components and then highlight the most recent developments in the post-carbon era of the field. In particular, we consider how the metallic dust form, mobilize, and interact with fusion plasmas and plasma facing components. Achievements in wall conditioning and associated anomalous plasma transport modification, including ELM suppression, with the powder injection technique is another focus of the paper. Capabilities of the state-of-art simulation tools to describe different aspects of dust in fusion devices are exemplified and new directions for future dust studies are brought forward. 

/pdf/dust-and-powder-in-fusion-plasmas-recent-developments-in-1lv5hn10.pdf

Dust and powder in fusion plasmas: recent developments in theory, modeling, and experiments

The transport properties of NSTX plasmas obtained during the 2008 experimental cam- paign have been studied and are reported here. Transport trends and dependences have been isolated, and it is found that both electron and ion energy transport coefficients have strong dependences on local values of nΔT, which in turn is strongly dependent on local current density profile. Without identifying this dependence, it is difficult to identify others, such as the dependence of transport coefficients on Bp (or q), Ip and Pheat. In addition, a comparison between discharges with and without Lithium wall conditioning has been made. While the trends in the two sets of data are similar, the thermal transport loss, especially in the electron channel, is found to strongly depend on the amount of Lithium deposited, decreasing by up to 50% of its no-Lithium value.

/pdf/characteristics-of-energy-transport-of-li-conditioned-and-jdoy2pzt4s.pdf

Characteristics of energy transport of Li-conditioned and non-Li-conditioned plasmas in the National Spherical Torus Experiment (NSTX)

The embodiment of the invention provides a lithium precipitation detection method and device, and relates to the technical field of batteries. According to the embodiment, a voltage signal is collected in the discharge process of a battery to be detected; then a discharge curve of the battery to be detected is obtained according to the voltage signal, wherein the discharge curve represents a relationship between voltage and discharge duration; thus, a voltage fluctuation curve of the battery to be detected is obtained according to the discharge curve, wherein the voltage fluctuation curve represents a relationship between the voltage and a second derivative of an electric quantity to the voltage; further, whether or not lithium of the battery to be detected is precipitated is detected according to the voltage fluctuation curve. Thus, the lithium precipitation detection method and device can solve the problems that by means of lithium precipitation detection methods for the battery in the prior art, a lot of manpower and material resources are consumed, and the detection efficiency is low.

Lithium precipitation detection method and device

The initial results of experiments involving the use of liquid lithium as a plasma facing component in the Current Drive Experiment-Upgrade (CDX-U) are reported. Studies of the interaction of a steady-state plasma with liquid lithium in the Plasma Interaction with Surface and Components Experimental Simulator (PISCES-B) are also summarized. In CDX-U a solid or liquid lithium covered rail limiter was introduced as the primary limiting surface for spherical torus discharges. Deuterium recycling was observed to be reduced, but so far not eliminated, for glow discharge-cleaned lithium surfaces. Some lithium influx was observed during tokamak operation. The PISCES-B results indicate that the rates of plasma erosion of lithium can exceed predictions by an order of magnitude at elevated temperatures. Plans to extend the CDX-U experiments to large area liquid lithium toroidal belt limiters are also described.

/pdf/liquid-lithium-experiments-in-cdx-u-f3beo49ltu.pdf

Liquid Lithium Experiments in CDX-U

The ability to increase the quantity of lithium deposition into TFTR beyond that of the pellet injector while minimizing perturbations to the plasma provides interesting experimental and operational options. Two additional lithium deposition tools were developed for possible application during the 1996 Experimental Schedule: a solid lithium target probe for real-time deposition, and a lithium effusion oven for deposition between discharges. The lithium effusion oven was operated in TFTR to deposit lithium on the inner limiter in the absence of plasma. This resulted in the third highest power TFTR discharge.

/pdf/development-of-lithium-deposition-techniques-for-tftr-3pni78itmt.pdf

Development of lithium deposition techniques for TFTR

The ability to increase the quantity of lithium deposition into TFTR beyond that of the Pellet Injector while minimizing perturbations to the plasma provides interesting experimental and operational options. Two additional lithium deposition tools were developed for possible application during the 1996 Experimental Schedule: a solid lithium target probe for real-time deposition, and a lithium effusion oven for deposition between discharges. The lithium effusion oven was operated in TFTR to deposit lithium on the Inner Limiter in the absence of plasma. This resulted in the third highest power TFTR discharge.

/pdf/development-of-lithium-deposition-techniques-for-tftr-t5hxafx0ng.pdf

This paper describes the spallation of lithium into TFTR by laser and operated during the last run period. Liquid droplets of lithium were delivered into the edge of TFTR plasmas at low velocities in order to coat the interior of the TFTR vacuum vessel, and study the effects on machine performance. A 1.6 Joule 1064 nm, 30 Hz pulsed YAG laser was used to form droplets from a heated cauldron containing liquid lithium. The cauldron was resistance heated and part of a new probe head attached to the existing Bay D Long Probe. The cauldron was moved into the bottom of the vacuum vessel and positioned in the shadow of a poloidal limiter. The laser, associated equipment, and beam expanding optics were located in a walled enclosure approximately 46 m from the cauldron. Three fixed mirrors directed the beam through the test cell wall and into a box containing the focusing optics, steering mirror and a remote viewing CID video camera system. The focused beam was aimed vertically downward through a vacuum window and into the lithium cauldron. The system was controlled using LabView/sup TM/ software. Safety issues were resolved with engineered hardware design, interlocked circuits and administrative control. Lithium was successfully introduced into TFTR. Some interesting physics results were obtained. There was insufficient time to optimize the operation and design but initial results point to interesting possibilities for future experiments. Laboratory tests indicated that the cauldron could feasibly be positioned horizontally or vertically.

DOLLOP (deposition of lithium by laser outside of plasma)-an overview [fusion materials]

This paper describes the spallation of lithium into TFTR by laser and operated during the last run period. Liquid droplets of lithium were delivered into the edge of TFTR plasmas at low velocities in order to coat the interior of the TFTR vacuum vessel, and study the effects on machine performance. A 1.6 Joule 1064 nm, 30 Hz pulsed YAG laser was used to form droplets from a heated cauldron containing liquid lithium. The cauldron was resistance heated and part of a new probe head attached to the existing Bay D Long Probe. The cauldron was moved into the bottom of the vacuum vessel and positioned in the shadow of a poloidal limiter. The laser, associated equipment, and beam expanding optics were located in a walled enclosure approximately 46m from the cauldron. Three fixed mirrors directed the beam through the test cell wall and into a box containing the focusing optics, steering mirror and a remote viewing CID video camera system. The focused beam was aimed vertically downward through a vacuum window and into the lithium cauldron. The system was controlled using LabViewTM software. Safety issues were resolved with engineered hardware design, interlocked circuits and administrative control. Lithium was successfully introduced into TFTR. Some interesting physics results were obtained. There was insufficient time to optimize the operation and design but initial results point to interesting possibilities for future experiments. Laboratory tests indicated that the cauldron could feasibly be positioned horizontally or vertically.

G. Labik

Papers

Development of lithium deposition techniques for TFTR

Development of lithium deposition techniques for TFTR

DOLLOP (deposition of lithium by laser outside of plasma)-an overview [fusion materials]

DOLLOP (Deposition of Lithium by Laser Outside of Plasma) An Overview