This webpage contains data on the reflectivity measurements of the WHT secondary mirror.
Reflectivity results - WHT Secondary Mirror
2018
|
Date |
BSDF 0°,0° (detector position) |
BSDF 50°,180° (detector position) |
Reflectivity (624 nm) |
CT7 model |
RMS (Å) |
File |
Notes |
23/03/2018 |
N/A | N/A | 87.0% | 5.2% | N/A | 20180323_WHTM2_cleaned.pdf | Soap&Water only increased Blue band %R ~1%; scattering reduced more by propanol wash |
2017
|
Date |
BSDF 0°,0° (detector position) |
BSDF 50°,180° (detector position) |
Reflectivity (624 nm) |
CT7 model |
RMS (Å) |
File |
Notes |
01/03/2017 |
N/A | N/A | 87.0% | 3.7% | N/A | 201703_WHTM2_check.pdf | Shows effects of ageing on a mirror 8 years after aluminising |
2016
|
Date |
BSDF 0°,0° (detector position) |
BSDF 50°,180° (detector position) |
Reflectivity (624 nm) |
CT7 model |
RMS (Å) |
File |
Notes |
16/05/2016 |
N/A | N/A | 87.6% | 4.5% | N/A | 20160516_WHTM2_chk.pdf | First meas. on M2 from CT7. SMS not used due to risk of staining. |
2013
|
Date |
BSDF 0°,0° (detector position) |
BSDF 50°,180° (detector position) |
Reflectivity |
RMS (Å) |
File |
Notes |
26/04/2013 |
1.9±0.1 E-03 | 1.6±0.2 E-04 | 85.9% ±0.3% | 60 ±4 | 20130426_WHTM2_check.pdf | No cleaning but values improved. Small sample (4) |
2012
|
Date |
BSDF 0°,0° (detector position) |
BSDF 50°,180° (detector position) |
Reflectivity |
RMS (Å) |
File |
Notes |
06/11/2012 |
2.8 E-03 | 2.5 E-04 | 0.842 | 69.8 | 20121106_WM2_chk.pdf |
More consistency than 2009 measurements |
2009
|
Date |
BSDF 0°,0° (detector position) |
BSDF 50°,180° (detector position) |
Reflectivity |
RMS (Å) |
File |
Notes |
16/04/2009 |
n/a | n/a | n/a | n/a |
Aluminisation (JR Logbook) No Reflectivity Data! |
|
19/01/2009 |
1.483E-03 | 3.510E-03 | 0.837 | 36.875 | 20090119WHTsec.pdf | Reflectivity measurement |
2004
|
Date |
Time |
BSDF 0°,0° (detector position) |
BSDF 50°,180° (detector position) |
Reflectivity |
RMS (Å) |
File |
Notes |
16/11/2004 |
|
|
|
|
|
|
Aluminising on 16/11/2004 |
2002
|
Date |
Time |
BSDF 0°,0° (detector position) |
BSDF 50°,180° (detector position) |
Reflectivity |
RMS (Å) |
File |
Notes |
26/03/2002 |
14:07:19 |
2.05E-03 |
2.67E-04 |
0.8798 |
51.942 |
WHTS263.PRN |
|
2000
|
Date |
Time |
BSDF 0°,0° (detector position) |
BSDF 50°,180° (detector position) |
Reflectivity |
RMS (Å) |
File |
Notes |
31/10/2000 |
11:18:02 |
1.14E-03 |
8.10E-05 |
0.8767 |
63.283 |
WHTSALUM.PRN |
|
25/10/2000 |
11:22:37 |
4.63E-03 |
6.59E-04 |
0.8817 |
62.264 |
WHTS2510.PRN |
|
25/10/2000 |
14:35:49 |
4.36E-03 |
5.41E-04 |
0.7812 |
65.191 |
WHTSWASH.PRN |
|
24/05/2000 |
11:02:37 |
8.24E-03 |
9.73E-04 |
0.8706 |
91.982 |
WHTSECB1.PRN |
|
24/05/2000 |
12:05:47 |
4.86E-03 |
5.75E-04 |
0.8761 |
71.206 |
WHTSECA2.PRN |
|