| Popis: |
The use of multiple-frequency microwave power for electron cyclotron heating (MFECH) significantly increased the ring stored energy in the SM-1 simple mirror device. MFECH was used on ELMO Bumpy Torus (EBT) in an effort to increase its hot electron beta. No substantial improvement in the ring parameters was observed in a series of two-frequency ECH experiments, with frequency separations up to 90 MHz, in contrast to the dramatic improvement found in the axisymmetric SM-1 experiment. The absence of superadiabatic behavior by the energetic electrons, combined with the effects of reduced heating efficiency and the additional ring losses introduced by the canting of the EBT mirror sectors, appears to limit the hot electron ring beta. |
