Re-aluminizing of 60cm mirror at Maidanak Observatory
Kiichi Okita*, Takashi Ito**, Fumi Yoshida**, Seitaro Urakawa***, Kenshi Yanagisawa*, Daisuke Kuroda*, Hisashi Koyano*, Eiji Kanbe*, Shinobu Ozaki**(* Okayama Astrophysical Observatory of NAOJ, **NAOJ, ***Spaceguard)
2nd Maidanak Observatory Users Meeting 2010.6.22
Date : 2010. 4. 12, 13
Done by : K.Okita, K.Yanagisawa, D.Kuroda, H.Koyano, E.Kanbe (Okayama) T. Ito, F. Yoshida, S. Urakawa (Asteroid group)
Re-Aluminizing sequence 1. Wash by water 2. Remove old aluminum by Sodium hydroxide(NaOH) 3. Polish by Sodium Hydrogen Carbonate ( 2NaHCO 3 ) 4. Wipe by cotton cloth with alcohol 5. Install mirror in the Vacuum chamber 6. Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 7. Ion-bombardment (3X10-2 torr 20min.) 8. One more Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 9. Spatter aluminum (6 times X 6 filaments about 30min.) 10. Take out mirrors from chamber 11. Packing mirror to transportation box.
60cm mirror (before re-aluminizing) 50cm mirror (before re-aluminizing)
Small mirrors (before re-aluminizing) Remove levels
Re-Aluminizing sequence 1. Wash by water 2. Remove old aluminum by Sodium hydroxide(NaOH) 3. Polish by Sodium Hydrogen Carbonate ( 2NaHCO 3 ) 4. Wipe by cotton cloth with alcohol 5. Install mirror in the Vacuum chamber 6. Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 7. Ion-bombardment (3X10-2 torr 20min.) 8. One more Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 9. Spatter aluminum (6 times X 6 filaments about 30min.) 10. Take out mirrors from chamber 11. Packing mirror to transportation box.
Wash, wash ! Remove old-aluminum by NaOH(10%)
Polishing by Sodium Hydrogen Carbonate
Re-Aluminizing sequence 1. Wash by water 2. Remove old aluminum by sodium hydroxide(NaOH) 3. Polish by Sodium Hydrogen Carbonate ( 2NaHCO 3 )
4. Wipe by cotton cloth with alcohol 5. Install mirror in the Vacuum chamber 6. Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 7. Ion-bombardment (3X10-2 torr 20min.) 8. One more Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 9. Spatter aluminum (6 times X 6 filaments about 30min.) 10. Take out mirrors from chamber 11. Packing mirror to transportation box.
Wipe mirrors using cotton cloth with alcohol
Re-Aluminizing sequence 1. Wash by water 2. Remove old aluminum by Sodium hydroxide(NaOH) 3. Polish by Sodium Hydrogen Carbonate ( 2NaHCO 3 ) 4. Wipe by cotton cloth with alcohol
5. Install mirror in the Vacuum chamber 6. Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 7. Ion-bombardment (3X10-2 torr 20min.) 8. One more Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 9. Spatter aluminum (6 times X 6 filaments about 30min.) 10. Take out mirrors from chamber 11. Packing mirror to transportation box.
Set-up mirrors in the Vacuum Chamber Lock the mirrors by chuck
Closing the chamber 60cm mirror
60cm
50cm
20cm 15cm
Re-Aluminizing sequence 1. Wash by water 2. Remove old aluminum by Sodium hydroxide(NaOH) 3. Polish by Sodium Hydrogen Carbonate ( 2NaHCO 3 ) 4. Wipe by cotton cloth with alcohol 5. Install mirror in the Vacuum chamber
6. Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 7. Ion-bombardment (3X10-2 torr 20min.) 8. One more Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 9. Spatter aluminum (6 times X 6 filaments about 30min.) 10. Take out mirrors from chamber 11. Packing mirror to transportation box.
Cryio-pump
Filament for heat-up Aluminum
Meissner-coil LqN2 flow into the copper pipe and Cool down, then trap water vapor in the chamber
At the opposite side that installed mirrors, there are 36 filaments at the wall of the chamber.
Re-Aluminizing sequence 1. Wash by water 2. Remove old aluminum by sodium hydroxide(NaOH) 3. Polish by Sodium Hydrogen Carbonate ( 2NaHCO 3 ) 4. Wipe by cotton cloth with alcohol 5. Install mirror in the Vacuum chamber 6. Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump)
7. Ion-bombardment (3X10-2 torr 20min.) 8. One more Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump)
9. Spatter aluminum (6 times X 6 filaments about 30min.) 10. Take out mirrors from chamber 11. Packing mirror to transportation box.
Ion-bombardment
Sputter aluminum from heated filament
A window glass of vacuum chamber coated from inside with Aluminum
Re-Aluminizing sequence 1. Wash by water 2. Remove old aluminum by Sodium hydroxide(NaOH) 3. Polish by Sodium Hydrogen Carbonate ( 2NaHCO 3 ) 4. Wipe by cotton cloth with alcohol 5. Install mirror in the Vacuum chamber 6. Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 7. Ion-bombardment (3X10-2 torr 20min.) 8. One more Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 9. Spatter aluminum (6 times X 6 filaments about 30min.)
10. Take out mirrors from chamber 11. Packing mirror to transportation box.
After re-aluminizing mirrors. 60cm, 50cm, small mirrors.
60cm main mirror
50cm main mirror
Re-Aluminizing sequence 1. Wash by water 2. Remove old aluminum by Sodium hydroxide(NaOH) 3. Polish by Sodium Hydrogen Carbonate ( 2NaHCO 3 ) 4. Wipe by cotton cloth with alcohol 5. Install mirror in the Vacuum chamber 6. Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 7. Ion-bombardment (3X10-2 torr 20min.) 8. One more Pumping vacuum camber into 5X10-6 torr. (Use the cryio-pump & the Meissner-coil pump) 9. Spatter aluminum (6 times X 6 filaments about 30min.) 10. Take out mirrors from chamber
11. Packing mirror to transportation box.
Pack mirrors in the box 60cm main mirror
50cm main mirror and small mirrors
Wyko NT1100 (Veeco co.)Height accuracy <0.3nmMeasurement accuracy about ~ 1nm
Measured 3 times each point
Result : 130nm ~ 140nm
Measurement of thickness 2010.5.13 by S. Ozaki (NAOJ) Preparation plate
(Use 3 plates)
Measurement point
Preparation plate from the side view
Aluminum