The highest energy confinement measured on TMX-U

Abstract

The highest confinement parameters measured on the Tandem Mirror Experiment-Upgrade (TMX-U) at Lawrence Livermore National Laboratory are summarized. The highest TMX-U global energy confinement product was 2 × 10l0 cm−3·s and the highest central cell electron temperature was 0.28 keV. Both were achieved during standard tandem mirror operation with a central cell density of 6 × 1012 cm−3. During thermal barrier operation, strong end plugging was limited to densities below 3 × 10l2 cm−3 and the maximum global energy confinement product was 0.6 × 10l0 cm−3·s. This performance is lower than that predicted by present theory but higher than that achieved in the earlier Tandem Mirror Experiment (TMX).

Electron cyclotron emission at the fundamental harmonic in GDT magnetic mirror

“…The exception was the TMX-U experiment at Lawrence Livermore National Laboratory where electron temperatures up to 0.28 keV were obtained with ECR heating (ECRH), but these studies were terminated soon after that 6 .…”

“…However, for many years the use of this method in open magnetic configurations has been limited either to plasma heating in relatively compact laboratory installations 1 , or to MHD stabilization and generation of fast electron population in a low-density plasma [2][3][4][5] . The exception was the TMX-U experiment at Lawrence Livermore National Laboratory where electron temperatures up to 0.28 keV were obtained with ECR heating (ECRH), but these studies were terminated soon after that 6 .…”

Threefold Increase of the Bulk Electron Temperature of Plasma Discharges in a Magnetic Mirror Device

“…This simplified view is widely spread over the fusion community. That in combination to many experiments which never demonstrated the electron temperature higher than 280 eV [6], led to a judgment that the very concept of a thermonuclear reactor based on a magnetic mirror has hit a dead end. This results in a relatively weak research activity in this field.…”

Quasi-optical theory of microwave plasma heating in open magnetic trap

“…However, for many years the use of this method in open magnetic configurations has been limited either by plasma heating in relatively compact laboratory installations 1 , or by MHD stabilization of low-density plasma [2][3][4] . The only exception was the TMX-U experiment at Lawrence Livermore National Laboratory where electron temperatures up to 0.28 keV were obtained with ECR heating, but these studies were concluded soon 5 . And only recently an efficient ECR heating of a dense (comparable to toroidal devices) plasma has been demonstrated at a large-scale mirror trap.…”