Development of the technique for spacecraft equipment examination on secondary arcing hazard

The problem of secondary arcing is actual if spacecraft power equipment operates at voltages of 70 V and higher that exceeds essentially the vacuum arc voltage drop. Such voltages are insufficient to ignite discharge unless the situation when protecting dielectric coating above populated circuit boards contains defects opening triple junction. To find defects and to recognize their parameters, we immerse equipment into the plasma environment and use power buses as a Langmuir probes. The technique is sensitive to find defects as small as 10
^-4
cm
²
in area with accuracy of coordinate measurement ±1 mm.