gary
24-02-2016, 11:03 PM
The Australian Astronomical Observatory (AAO) have posted
photo galleries on their Facebook page which show the process of
cleaning and re-aluminising the 3.9m mirror.
The observatory has its own vacuum chamber in a floor below the
telescope and the mirror is removed and lowered down to that
floor whenever it needs re-aluminizing, typically on an annual basis.
See that process here -
https://www.facebook.com/AustralianAstronomicalObservatory/photos/ms.c.eJw9kMkRAzAMAjvK6LCu~;htLgoyfO wKMGWnTqhOj7nI~_sxxjJ9OTfCxqpvRyJ~_ 4W5L3nuyPP5ua1OLioH4c~_jFzI06c3sAx5 7~_zXqvD70w~;yk3rNZSPX8u3XJuBoMt6Lp t8F~_Rq8B9iE3Kv3y2f~;~_~;p4Qv~;6~_y wn9Qp~;yfPvnf1O~;7mnyLNMf~_ye3L8jlt knDvKD~;t~_SYOYn9u~;mPlng4h7ZyFP2y9 1X5gsDBHJT.bps.a.908217709246641.10 73741860.392918577443226/908217745913304/?type=3&theater
The mirror weighs 16.19 tonnes and is fabricated from Cer-Vit (https://en.wikipedia.org/wiki/Cer-Vit)glass.
The diameter of the central hole is 1.067m.
In one image you will see a close-up of the 2.5g coil of aluminium
which is vaporized in the vacuum chamber and provides the mirror surface.
Cleaning and coating gallery here -
https://www.facebook.com/AustralianAstronomicalObservatory/photos/ms.c.eJw9ktuRxTAIQzvaMWBe~;Te2uchi8 nUikAV2nzK~;19Uj7Jy~;BuePtYtcraYd9t gF~_n0c4CJ~;X3WHLgdYWX~_Ghf7e4KZuYC ejX7YfeS7zJPwO~;VInT66uU2~;0T~;Tb6o l~_eVz~_Y2~;qZVOvtfr4B~;dVNez5uLEP5 ~;yf1a9fgjzzeb35~;Ohwro79X57XjX7deu hGhv8JcoLf~_S4zn4eQZx~;fL3JAp7~;Mfb hTV~_R15rUz~;UU~;veAkF5j5LCbv6eXRk3 4X~_9q8F~;MdW33ON~;p~;x326dCyPrr08~ ;juPzz6liozzd57vJqb~;3aeHoZ79Me~;Zh fkSeQ7z4H0V39enT39uPfbP9~_U1frdXxzz BeUqg0x~;vr~;j~_vDCPkxv3ofRv5JH~_B~ _aiy88~-.bps.a.908354422566303.1073741861.3 92918577443226/908354452566300/?type=3&theater
photo galleries on their Facebook page which show the process of
cleaning and re-aluminising the 3.9m mirror.
The observatory has its own vacuum chamber in a floor below the
telescope and the mirror is removed and lowered down to that
floor whenever it needs re-aluminizing, typically on an annual basis.
See that process here -
https://www.facebook.com/AustralianAstronomicalObservatory/photos/ms.c.eJw9kMkRAzAMAjvK6LCu~;htLgoyfO wKMGWnTqhOj7nI~_sxxjJ9OTfCxqpvRyJ~_ 4W5L3nuyPP5ua1OLioH4c~_jFzI06c3sAx5 7~_zXqvD70w~;yk3rNZSPX8u3XJuBoMt6Lp t8F~_Rq8B9iE3Kv3y2f~;~_~;p4Qv~;6~_y wn9Qp~;yfPvnf1O~;7mnyLNMf~_ye3L8jlt knDvKD~;t~_SYOYn9u~;mPlng4h7ZyFP2y9 1X5gsDBHJT.bps.a.908217709246641.10 73741860.392918577443226/908217745913304/?type=3&theater
The mirror weighs 16.19 tonnes and is fabricated from Cer-Vit (https://en.wikipedia.org/wiki/Cer-Vit)glass.
The diameter of the central hole is 1.067m.
In one image you will see a close-up of the 2.5g coil of aluminium
which is vaporized in the vacuum chamber and provides the mirror surface.
Cleaning and coating gallery here -
https://www.facebook.com/AustralianAstronomicalObservatory/photos/ms.c.eJw9ktuRxTAIQzvaMWBe~;Te2uchi8 nUikAV2nzK~;19Uj7Jy~;BuePtYtcraYd9t gF~_n0c4CJ~;X3WHLgdYWX~_Ghf7e4KZuYC ejX7YfeS7zJPwO~;VInT66uU2~;0T~;Tb6o l~_eVz~_Y2~;qZVOvtfr4B~;dVNez5uLEP5 ~;yf1a9fgjzzeb35~;Ohwro79X57XjX7deu hGhv8JcoLf~_S4zn4eQZx~;fL3JAp7~;Mfb hTV~_R15rUz~;UU~;veAkF5j5LCbv6eXRk3 4X~_9q8F~;MdW33ON~;p~;x326dCyPrr08~ ;juPzz6liozzd57vJqb~;3aeHoZ79Me~;Zh fkSeQ7z4H0V39enT39uPfbP9~_U1frdXxzz BeUqg0x~;vr~;j~_vDCPkxv3ofRv5JH~_B~ _aiy88~-.bps.a.908354422566303.1073741861.3 92918577443226/908354452566300/?type=3&theater