In-situ Cleaning of Telescope Optics

Last updated March 2007

Principle of CO2 cleaning: solid CO2 knocks off the particulates and gaseous CO2 blows them off.

MSDS (CO2 could be hazardous!)

• gaseous CO2 disables the respiratory system (some notes)
• solid CO2 (dryice) for chillburn

Cleaning devices at Subaru

• for primary mirror: in-situ, automated cleaning system
• Primary mirror cleaning device - technical drawings
  • overall view from the top and the side
  • nozzle and attachment
  • ball screw drive
  • plumbing, nozzle and holes
• for other smaller mirrors: small portable cylinder and a nozzle

Primary Mirror Cleaning: manual English | Japanese (or see Kanzawa san)

• pictures: nozzle | mirror cover open | reflection
• 02-04-02: dryrun | arm1 | arm2 | arm3| arm4 (colorful spider mirror)

Other (old) information (Japanese)

Primary Mirror

	3/8/2007
	2/6/2007
	12/14/2006

8/1/2006 M1 recoated (reflectivity measurement on 8/2/2006)

serial	date of CO2 cleaning	note
41	6-7-2006
40	4-13-2006	March was terrible.
39	2-9-2006
38	1-10-2006	5 cylinders
37	12-29-2005	5 cylinders
36	11-15-2005
35	10-21-2005
34	10-04-2005
33	08-31-2005
32	07-26-2005
31	06-28-2005
30	06-01-2005
29	04-20-2005
28	04-06-2005
27	02-25-2005	Arm 2 strange
26	02-11-2005	Arm 2 strange
25	11-26-04
24	11-03-04
23	10-08-04
22	09-21-04
21	08-26-04
20	08-10-03
19	07-30-04
18	07-16-04
17	06-29-04
16	05-26-04
15	05-13-04
14	04-26-04
13	04-15-04	March bad weather
12	02-13-04
11	01-21-04
10	01-09-04	First of year 2004
9	12-23-03	Last of year 2003
8	12-11-03
7	11-20-03
6	11-04-03
5	10-16-03
4	09-30-03
3	09-17-03
2	09-04-03
1	08-21-03

Recoating on August 5, 2003

serial	date	uScan data	note
(38)	07-08-03		(bottom part)
37	06-19-03	no
36	06-06-03	no
35	05-19-03	no
34	05-02-03	no	(weather & IRCS restriction)
33	03-27-03	no
32	03-05-03	no
31	02-25-03	no
30	01-27-03	no
29	01-08-03	no
28	12-26-02	no
27	12-03-02	no
26	11-20-02	no
25	11-06-02	no
24	10-23-02		(M3 cleaning)
23	10-10-02	no
22	09-24-02	no
21	09-10-02	no
20	08-27-02	no
19	08-01-02	no
18	07-17-02
17	07-05-02
16	06-20-02
15	06-05-02	no
14	05-21-02
13	04-24-02
12	04-10-02
11	03-27-02	no
10	03-13-02	no
9	02-25-02
8	02-04-02
			Break due to high humidity
7	01-09-02	no
	12-20-01
6	12-19-01	no
	12-12-01
5	11-28-01	no
4	11-14-01
3	10-29-01	no
	10-25-01
2	10-10-01	no
1	09-18-01	no	Cleaning device test
	09-11-01		coating

serial	CO2 cleaning	note
29	July 18, 2001	last before shut down
28	July 3, 2001
27	June 14, 2001
26	May 16, 2001
25	April 25, 2001
24	April 4, 2001
23	March 13, 2001
22	Feb. 27, 2001
21	Feb. 6, 2001
20	Jan. 17, 2001
19	Dec. 27, 2000	no measurement
18	Dec. 6, 2000
17	Nov. 15, 2000
16	Oct. 31, 2000
15	Oct. 5, 2000,	no measurement
14	Sep. 20, 2000
13	August 30, 2000
12	July 25, 2000
11	July 6, 2000
10	June 8, 2000,	measurement June 9
9	March 2, 2000	late Mar.- FP accident
8	Feb. 4, 2000
7	Jan. 5, 2000
6	Dec. 8, 1999	Operation handed over from test group to the regular group.
5	Nov. 23, 1999
4	Nov. 9, 1999
3	Oct. 26, 1999
2	Oct. 8, 1999
1	Sep. 23, 1999	for the first time
	August 13, 1999	re-aluminization

microScan calibrations

• (December 2002) uscan 670 nm sencor re-calibrated
• 10/03/00 uScan 670nm and 1300nm sensors re-calibrated
• 01/07/00 uScan 1300nm sensor re-calibration
• 04/13/99 uScan 1300nm sensor re-calibration
• 03/26/99 uScan 1300nm sensor original calibration
• 04/24/98 uScan 670nm sensor original calibration

Secondary mirrors

• CsOpt M2 repair work, August 2004 (no cleaning applied)
• IR M2 cleaned by Kurakami, after glass repair work

Tertiary mirrors

• Dec. 15, 2000, Tertiary mirrors (optical and IR) CO2 cleaned
• 1999.8 Optical Nasmyth Tertiary cleaned upon arrival.

Image rotators

• optical image rotator cleaned by Okita and Yutani, autumn 2000
• IR image rotator cleaned 05-17-00 by Okita and Kurakami, again on 02-21-02 by Okita and Namikawa (uscan data)