Part No. 404-0031 RPA Grid Set
- Replacement grid set for the 404-0008 Small-Area RPA: 4 meshed grids + 1 collector electrode.
ECCN: EAR99
HTS: 903033
RPA meshed grids are subject to sputter erosion when exposed to an ion beam. Over time, ion impact can progressively thin and remove the mesh material along the beam path. In many cases, erosion is not detectable electrically or mechanically during operation. The meshed grids are electrically isolated by design. Because sputter erosion does not necessarily create an electrical short, the grid may remain electrically isolated even after significant material loss. As a result, electrical continuity checks are not a reliable indicator of mesh integrity.
Once the mesh is significantly thinned or fully removed, the RPA may exhibit degraded or unphysical analyzer signals:
- Loss of energy discrimination
- Increased signal magnitude due to unfiltered ion transmission
- Flattened or distorted I–V characteristics
- Reduced repeatability between scans
As a result, visual inspection may be the only reliable method for determining whether a mesh has been eroded.
Replacement of the parts requires disassembly and reassembly of the unit.
Entrance aperture diameter: 1.27 cm (0.5 in)
Grid open area: 77% each grid (100 lines/inch, square hole width 0.0088 inch).
Grid material: SS 316
Lead Time: Typically 4 weeks if not in stock.
