Repairing the Gemini North Wind Blind
Both Gemini domes are equipped with a three-segment wind blind , which is deployed by moving the lower shutter to shield the telescope structure from wind coming from the direction of the open slit ( Figure 4 ). Gemini North ’ s wind blind has caused concern since early 2015 , when we found excess wear on the track and roller system during regular maintenance . Considered a serious problem , we disconnected it in the second half of 2015 ( when historically winds are lowest ) to decrease run time and wear .
We reconnected the wind blind in November , to provide shielding during this more windy period , but decreased its maximum travel from 60 to 55 degrees . With Base Facility Operations in the North now implemented , we are able to focus on this problem and plans are now in place to work on it over the Northern Hemisphere summer . The project involves replacing all tracks guiding the wind blind and all guide roller assemblies , and performing repairs on any other damage found .
This is a major job , requiring three different pieces of heavy equipment , including a 120-ton mobile crane . We have requested and received approval to hire and use that equipment on Maunakea . Work will start immediately after the July 4th holiday , and will continue for two weeks . Observers cannot use the wind blind at night throughout this period . We ’ ll report on the outcome in a future edition of GeminiFocus . The equivalent system at Gemini South has been inspected and shows no signs of similar problems , however , the process is being documented by staff to assist on future possible work .
DR User Forum
The Gemini Data Reduction ( DR ) User
Forum is a platform created for trading ideas , scripts , and best practices . Anyone is invited to ask questions or trigger discussions about data reduction , processes , and strategies . The DR Forum permits immediate diffusion to a broad audience . It allows users to have the attention of many experts that would otherwise be difficult to contact . The Forum also offers a different , more direct , channel to contact Gemini staff , instrument builders , and experienced researchers .
Please visit , search , read , and contribute to the Gemini DR Forum . If you would like a new topic to be covered , simply register ( if you have not already ) and add it to the discussions . Each new post will receive attention promptly .
For additional questions or comments , please contact us at : sus _ inquiries @ gemini . edu
Figure 4 . The Gemini wind blind design drawings . Left : blind segments all stowed , with the guide tracks above them following the shape of the dome arch . Right : detail of the segments ; the largest is 5.5 meters ( 18 feet ) high .
Is the DR Forum for you ? The answer is probably yes , but especially if :
• You are performing optical or infrared data reduction for the first time : — Because you are working on your thesis — Because you are expanding your work to include wavelength bands or instruments with which you are not particularly familiar .
• You are adept with optical and infrared reduction but would like to share best practices with your colleagues so they can utilize good habits , which will lead to clearer and more accurate descriptions of their data reduction methods .
• You are simply facing a specific issue with your current data reduction , and you want to share your questions or solutions with a broad community of astronomers .
July 2016 GeminiFocus
13