Speaker
Description
In a Vacuum Arc with a Black Body Assembly (VABBA), cathode material is
emitted into a closed chamber formed by the end surface of a water-cooled cylindrical
cathode and a cup shaped refractory anode that is heated by the arc. Material is eroded from
the cathode spots as plasma and MPs. They impinge on the hot anode and are re-evaporated
from it, forming a dense high-pressure plasma within the chamber. The closed chamber
operates as a black body for the macroparticles (MPs) while the plasma can be emitted
through either a single small anode apertures or a “shower head” array of holes.
In the present study, the Cu cathode was a 30 mm diameter and the anode was 50 mm outer
diameter and 40 mm inner diameter, and constructed from Ta. The arc plasma was ejected
through an array of 250 holes of 0.6 mm diameter in the anode. The arc currents were I=175,
200 and 225 A and the arc duration was 160 s. The anode temperature was measured using
high-temperature thermocouples in the top and side of the anode body. The observed anode
temperature increased sharply during a transient time of ~70-90 s and then it slightly
increased with time up to 160 s, reaching 1650 K (I=175 A) and 1850K (I=225 A) on the top,
and 150-200 K lower on the side.
| session | Experiments and Diagnostics |
|---|---|
| Type of contribution | Poster |
