Slit nozzle and its effect on the stability of induction discharge in the channel of a high-frequency electrodeless plasmatron
This paper studies the discharge existence domain in the cylindrical channel of the IPG-4 inductively coupled plasma facility when slit nozzles with outlet sections of 40×8, 80×15 and 120×9 mm are installed behind it. For each nozzle, the relationship of the pressure in the discharge channel vs the power of the anode supply of the HF-generator was measured under the supersonic outflow regime. The power values of the anode supply of the HF-generator at which discharge extinction takes place were determined for various pressures in the discharge channel under subsonic outflow regimes. The obtained discharge existence domain was compared with the data for the regimes with no nozzle behind the discharge channel of the facility. It was shown that slit nozzles (contrary to expectation) have a weak effect on the discharge extinction boundary in the region of high (>100 hPa) pressures in the discharge channel.
Исследованы области существования разряда в цилиндрическом канале индукционного плазмотрона ВГУ-4 при установке за ним щелевых сопел с размерами выходных сечений 40x8, 80x15 и 120x9 мм. Для каждого сопла измерены давления в разрядном канале в зависимости от мощности анодного питания ВЧ-генератора плазмотрона при сверхзвуковом режиме истечения. В дозвуковых режимах истечения для различных давлений в разрядном канале определены значения мощностей, при которых происходит срыв разряда. Проведено сравнение полученных областей существования с данными для режимов, реализуемых без установки щелевых сопел за разрядным каналом плазмотрона. Щелевые сопла вопреки ожиданию слабо влияют на границу срыва разряда в области высоких (более 100 гПа) давлений в разрядном канале.
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