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M1 and M2 reflectivity measurements using IRIS

Old reflectivity measurements

The M1 was washed on May 2015 and again November 2016. The plot below shows the fresh aluminum literature reflectivity (black line), the 2014 reflectivity before (magenta) and after realuminisation (green) and reflectivity after wet washing, May 2015 (blue) and November 2016. The briefcase indicates test plates which are kept in a briefcase in the mechanics room. These measurements were taken with the ING reflectometer.
A comment from Neil O'Mahony (the ING Optics Technician) "Your scattering is also as good as we've got in the past. So I think you can be happy with your cleaning technique, especially in the extreme bands"

The M1 and M2 were realuminised on June 2014 (previously July 2009).

Date Reflectivity % 4700Å Reflectivity % 5300Å Reflectivity % 6500Å Reflectivity % 8800Å Mirror Device Comment
27.03.2014 89.0+-0.4 88.7+-0.3 87.7+-0.4 82.7+-0.2 M1 TNG M1 washing 18.03.2014
20.06.2013 89.6+-0.4 89.5+-0.4 88.0+-0.4 83.3+-0.3 M1 TNG after washing
20.06.2013 86.7+-0.6 86.5+-0.5 85.5+-0.4 80.3+-0.3 M1 TNG before washing
20.07.2012 88.2+-0.5 87.7+-0.4 86.4+-0.3 81.2+-0.6 M1 TNG  
02.12.2011 89.1+-0.6 88.5+-0.4 87.4+-0.3 81.8+-0.3 M1 LT  
02.11.2009 88.6+-0.2 87.5+-0.2 85.7+-0.2 79.7+-0.3 M1 LT  
02.12.2011 91.0 90.0 87.8 82.2 M2 LT  
02.11.2009 91.6 90.5 88.6 82.6 M2 LT  
Scattering (6700Å)
Date BRDF -45 BRDF -15 BRDF +2 Mirror Device Comment
27.03.2014 5.1e-4 1.1e-2 1.0 M1 TNG TIS=1.5%
20.06.2013 5.4e-4 1.0e-2 0.8 M1 TNG TIS=1.7%
20.07.2012 2.2e-3 2.8e-2 1.8 M1 TNG TIS=3.4%
02.11.2009 3.2e-3 1.8e-2 2.1e-2 M1 LT  


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