Speaker: Dick Majeski , Princeton Plasma Physics Laboratory
Abstract: Almost all tokamaks operate in a regime where the recycling coefficient approaches 1. The recycling coefficient is defined, in the absence of other fueling, simply as (the # of particles entering the plasma)/(the # of particles exiting the plasma). WIth a high recycling wall, plasma which diffuses across the last closed flux surface in a tokamak, and is lost from the scrape off layer, is reflected or desorbed as ions, electrons, and neutral atoms from the limiters, divertor plates, and other plasma facing surfaces. The LIthium Tokamak eXperiment (LTX) is - or was - the only magnetic confinement device to have demonstrated operation with a measured recycling coefficient < 0.5, through the use of clean, solid or liquid, lithium walls and plasma limiting surfaces. Here we discuss the modifications to the plasma core and edge which result from the imposition of a low recycling lithium boundary on a tokamak plasma, as documented in LTX.