1. COATING
2 coating plants for Aluminium evaporation
4m chamber (used only for M1 of 4m tel.)
- 6-day process, 4-6 people
- 104 filaments on 4 rings (original NOAO plant): thickness uniformity +/-25%
- Glow discharge (3000V, 3A, 20min)
- 6.10-6 Torrs with 2 diffusion pumps
- 600-1000 Å deposited, 43Å/s max
- Total time of power in filaments: 4’ ; total aluminizing time: 45”
- Sigma SQM160 thickness monitor
- Total time of coating process: about 6 hours