On a burning plasma low recycling regime with P_(DT) = 23-26 MW, Q_(DT) = 5-7 in a JET-like tokamak

摘要

The recent invention of a continuously flowing liquid lithium system, called 24/7-FLiLi, opens the opportunity to design a plasma pumping divertor which can significantly suppress plasma edge cooling by recycling.The paper describes the expected performance of deuterium-tritium burning plasma with low recycling using a tokamak of JET size, magnetic field and plasma current as an example.So far, only the technological aspects of flowing lithium have been tested on the HT-7 and EAST tokamaks (ASIPP, Hefei, China) with no attempts to create the low recycling regime. The compatibility of 24/7-FLiLi with tokamak plasma was confirmed and some mistakes in the design were revealed, thus, requiring another fabrication approach. Now, with the proper design of the Li system, recycling as low as 0.5 seems to be achievable.The suppression of plasma cooling by recycling in combination with neutral beam injection (NBI) for core plasma fueling by energetic particles automatically leads to 'the best possible confinement regime', uniquely compatible with burning plasma. This paper outlines the conceptual details of the 24/7-FLiLi divertor for a JET size tokamak. The main focus is in regard to the physics of the low recycling regime as well as to the expected performance of the burning plasma. In comparison with the results of 1994 on TFTR and 1997 on JET, the projected performance is astonishing: fusion power P-DT = 23-26 MW, fusion efficiency Q(DT) = 5.7 - 6.4, tritium burn up 7.8%-8.7% with modest NBI power P-NBI = 4 MW, and energy E-NBI = 120 keV. This new regime could resolve the outstanding plasma physics issues related to burning plasma that are unsolvable with the currently dominant approach.