2D emission intensity measurement of the Balmar series for attached/ detached plasma formation with ICR heating using TPDsheet-U

The two-dimensional (2D) emission intensity distributions of the Balmer series (H alpha, H beta, and H gamma) during ion cyclotron resonant heating (ICRH) have been measured using a high-speed camera equipped with an Arbaa prism to investigate the effect of stored energy, represented by ion temperature, on the detached plasma formation in a divergent magnetic field configuration. When the resonance frequency wRF, which is about 1.2 times the ion cyclotron frequency wci of hydrogen ions, is applied to the sheet plasma and the stored energy (ion temperature) is increased, the H beta and H gamma emission intensities at the periphery of the detached plasma decrease, while the electron temperature at the plasma center increases from 1 eV to several electron volts, resulting in a transition from detached to attached plasma.