Cryogenic Lens Mounts 1

[WilliamHerschel]

I am trying to design a series of lens mounts which can be used at 77K. Obviously I need to align them at room temperature, but I need to maintain this alignment. The lenses need to be concentric to 20microns, and maintain this through all gravity vectors!<br>
<br>
I would appreciate any assistance in this matter.

 

[Studious]

Need more information. What materials are being used for the elements (coefficient of expansion)? Are there any shock and vibration considerations? How large are the elements? How many elements? Does each air gap need a vent? Are you going to purge the air cavities with Nitrogen? Are you planing on packaging each element individually then making an assembly (lens assembly) or making one optical package?<br>
<br>
Grant is the best person I know to get you pointed in the right direction, he can be contacted at grant@scepter.net or (925) 556-0550. Grant has done many Optical-packaging programs for military airborne systems.<br>

 

[Tom584]

William,<br>
<br>
Have you considered using invar as a material for your mounts? It has a very low coefficient of thermal expansion; however, it does corrode with moisture so it will have to have a surface treatment. <p>Tom Worthington<br><a href=mailtoworthi@astro.as.utexas.edu>pworthi@astro.as.utexas.edu</a><br><a href= > </a><br>

 

[alpinecryo]

There is a cryogenic treater, near Boston, who treats such mounts used in space to
make the mount stable. He seems to be successful at it. If you are still interested, you can e-mail me and I'll give you his phone number ( dougb@alpinecryo.com) Dougb

 

[Jerre]

There are a lot of problems associated optics at cryogenic temperatures. I found in my designs experience that reflective optics are the prefered optical system. It is the easiest to design and fabricate.