Review of Scientific Instruments
Simulations indicate that during flattop current discharges the optimal angles for the aiming of the National Spherical Torus Experiment (NSTX) antennae are quite rugged and basically independent of time. The time development of electron Bernstein wave emission (EBWE) at particular frequencies as well as the frequency spectrum of EBWE as would be seen by the recently installed NSTX antennae are computed. The simulation of EBWE at low frequencies (e.g., 16 GHz) agrees well with the recent preliminary EBWE measurements on NSTX. At high frequencies, the sensitivity of EBWE to magnetic field variations is understood by considering the Doppler broadened electron cyclotron harmonics and the cutoffs and resonances in the plasma. Significant EBWE variations are seen if the magnetic field is increased by as little as 2% at the plasma edge. The simulations for the low frequency antenna are compared to preliminary experimental data published separately by Diem et al.
Original Publication Citation
Preinhaelter, J., Urban, J., Pavlo, P., Taylor, G., Diem, S., Vahala, L., & Vahala, G. (2006). Electron Bernstein wave simulations and comparison to preliminary NSTX emission data. Review of Scientific Instruments, 77(10F524), 1-4. doi: 10.1063/1.2336467
Preinhaelter, Josef; Urban, Jakub; Pavlo, Pavol; Taylor, Gary; Diem, Steffi; Vahala, Linda L.; and Vahala, George, "Electron Bernstein Wave Simulations and Comparison to Preliminary NSTX Emission Data" (2006). Electrical & Computer Engineering Faculty Publications. 27.