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