Cannot find beam on fluscreen
These are possible resolutions for the issue:
- Remove pumping aperture to check the hole and place it back
These are possible causes for the issue:
- Beam was blocked in the beam path
- Open column valves
- Check FEG is on Operate (button is yellow)
- Check HT is on and at maximum HT
- Set the extractor to Voptimal and Gun Lens 1 Spot Size 1
- Make sure there is FEG emission
- With holder but no sample select spot size 1
- Flu cam settings on “Natural” and not in High resolution mode
- Select LM magnification ~120 x.
- Change Intensity knob in both directions and watch flu-screen if beam becomes visible.
- Check the beam shift values and set it to 0 if needed.
- Check the Gun tilt alignment.
- use shutter blanker monitor to verify is there some staff block the beam.
All above actions looks good, but still cannot find beam, FSE cannot find laser beam pass through top of C1 model to end of P2, and can only find beam around SA AP.
Solution: Removed pumping aperture and clean it with specific tools after open Vcp manually with Vmco in Vacuum Overview after SWAP air tube Vmco and Vcp from solenoid valves on the rear side of basis. After confirm pumping aperture is clean and put it back and check beam path with laser again. Confirmed laser pass through from the top of C1 to the end of P2, then find beam on fluscreen finally.