Energy confinement studies in the tandem mirror experiment (TMX): Power balance

The power balance in the Tandem Mirror Experiment (TMX) is studied for several days of operation. Between them, these days typified the operating range of TMX. Examining the power balance on axis, it is found that 60% to 100% of the power is carried to the end walls by escaping central‐cell ions. Globally, these calculations account for 70% to 100% of the input power on each of the days studied. Based upon the power balance, the energy confinement times of the particle species are calculated. The end‐cell ion energy confinement time is similar to that achieved in the 2XIIB single‐cell magnetic mirror experiment, whereas the electron energy confinement in TMX was 10 to 100 times better. The central‐cell ion energy confinement in the central flux tube was determined by axial particle loss. At the central‐cell plasma‐edge radial particle transport and charge exchange with the fueling gas are important processes.