solder for UHV

I am working on a system under UHV at very low temperature. Now I need to solder thermocouple wires to feedthrough (i.e. two copper pins
sticking inside from one fo the vacuum port.
I want to solder thermocouple wires of extremely low temperature (~10K) for UHV applications. It appears that lead-free solder (e.g. 95%tin5%silver) works but I have no experience so far. So I want to know the answers for the following questions. If you know, please let me know!
1) what shuold I need to consider for soldering? 1) what materials should I use? Lead-free solder (tin-silver)? 2) where can I buy it?
Thank you for your support in advance!!
Nanoworld
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Nanoworld wrote:

Is there an electron microscope lab in your department? If so, how would they do it?
(Maybe they'll do it for you.)
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On Wed, 12 Apr 2006, Nanoworld wrote:

    Lakeshore have some application notes regarding use and installation (http://www.lakeshore.com/temp/sen/smindex.html ) of thermocouples: http://www.lakeshore.com/temp/sen/thermdn.html
--
Dr. Danny Chrastina.

Office: +39 031 3327356 Everywhere else: +39 333 2825623
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Nanoworld wrote:

Don't use copper feedthroughs! You're actually going to have 6 junctions in series instead of only 2, if you do that. You can get UHV thermocouple feedthroughs specially made for this. Your best bet for connections in UHV is spot welding rather than soldering, if you can do it.
Cheers,
Phil Hobbs
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On Thu, 13 Apr 2006, Phil Hobbs wrote:

    I've had another thought: are you really going to be trying to measure temperatures of 10K with a thermocouple? Wouldn't a thermistor with a negative temperature coefficient be better for that?
--
Dr. Danny Chrastina.

Office: +39 031 3327356 Everywhere else: +39 333 2825623
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According to my experienc we welld thous two wites with arc or spark. without any additional oxide preventing materials. We just path through the wires a spark directly on the contact between them. The spark was generatad in open aire using potential of severals KV.
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According to my experienc we welld thous two wites with arc or spark. without any additional oxide preventing materials. We just path through the wires a spark directly on the contact between them. The spark was generatad in open aire using potential of severals KV.
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According to my experienc we welld thous two wites with arc or spark. without any additional oxide preventing materials. We just path through the wires a spark directly on the contact between them. The spark was generatad in open aire using potential of severals KV.
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replying to Nanoworld, PHYSIKE wrote: please see followed URL
http://www.physike.com/product3.asp?sid &cidp&bid0
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