Current density on the cathode of high current vacuum arc stabilized by axial magnetic field

Abstract

Current density distribution over the cathode of high-current vacuum arc (HCVA) stabilized by axial magnetic field (AMF) was analyzed and mean values were found. Results obtained proved previously discovered phenomenon of normal current density in cathode root of HCVA stabilized by AMF to be of general phenomenon under changes of arc parameters in a wide range. This normal current density depends on AMF intensity and on arc length,'and does not depends on current. It was also discovered that inside cathode arc root, cathode spots form a characteristic structure.

A two-dimensional mathematical model of a short vacuum arc in external magnetic field: results of numerical calculations

“…Although such a problem was never solved (and was not even posed), some general observations may be made. It is known [9,10] that a large number of cathode spots, which fill quite uniformly the cathode surface taken up by current, function simultaneously in a high-current VA with longitudinal magnetic field on the cathode (for example, CuCr cathode). A plasma cathode flame exists above each cathode spot.…”

The effect of axisymmetric two-dimensional magnetic field on the configuration of vacuum-arc plasma

“…The external magnetic field may affect the configuration of VAD plasma and, therefore, the configuration of cathode spots. This effect was demonstrated by Chaly et al [4,5] who studied the distribution of VAD cathode spots over the cathode surface in an axial magnetic field (CuCr electrodes). In this case, the cathode spots are distributed quite uniformly over the cathode surface.…”

Динамика Катодных Пятен В Аксиальном Магнитном Поле На Спаде Импульса Тока В Сильноточной Вакуумной Дуге

“…Коротко перечислим полученные ранее результаты [7][8][9], которые позволяют объяснить описанное выше изменение формы катодной…”

“…Продолжение работы показало, что обнаруженная закономерность сохраняется при изменении тока дуги в значительно более широких пределах (на порядок величины и более) [8]. Измерения в [7,8] проводились в дугах длиной h = 6 mm с медь-хромовыми электродами.…”

“…Измерения в [7,8] проводились в дугах длиной h = 6 mm с медь-хромовыми электродами. Аппроксимация экспериментальных результатов [7,8] позволила полу-чить выражения для B 1 ( j 0 ) [3] и для j nor m (B), в которых j измеряется в kA/cm 2 , а B -в теслах:…”