went to Downs to get the right crimp tool for the d-sub connectors. It's a DMC crimper for D-sub contacts for UHV connectors (crimp tool). Turns out that the DMC tool does not properly fit the contacts we have, (female pins).. The contacts we have are NASA approved, space qualified, low outgassing crimp contacts (link) and are the same as delivered with the aLIGO, in-vacuum PEEK D-sub connectors. The crimp location seems to be too high for those contacts, but is still working. The insert is the correct one (description), (pdf).

Interesting is that the pins which come with the UHV connector have little colored markings on them as can be seen on the picture (see above link to female pins). Marking can not be removed with methanol, acetone etc.. My guess is that it's OK and actually might be not simply paint.

Will use d-sub contacts to crimp on the nicrome wire and run kapton insulated copper wire to the main vacuum feedthrough. Having the contacts right next to the copper tube makes it a lot easier to work on the whole cavity assembly.

• wire can be stripped using an old rotary sanding tool where only the matrix is left (no abrasive stuff left).
• Crimp tool has to be set to setting 1(!) to crimp correctly, default is 5.
• clamped the wire using #2-56 screws and washers facing round side down to not have sharp edges which could cut the insulation of the wire.
• added tiny amounts of the super thin kapton tape to further protect the wire
• total amount of turns is 21
• total resistance is 154ohms - calculated value was 147ohms
• crimped femaile contacts to both ends