In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.
Subject: Weekend Activities
Date: May 16, 0:44 am
Poster: Richard Hester
On May 16, 0:44 am, Richard Hester wrote:
I was a tad busy this weekend. A parts run to a local geekfest and a couple of surplus stores netted me various vacuum fittings, a couple of valves, and the prize of the day, an 80's vintage multichannel analyzer (Canberra Series 30). The auto parts store around the corner had plenty of AC44XLS spark plugs (HV feedthrough). The threaded portion of the plug comes off pretty cleanly using a Dremel tool with an emery cut-off wheel (wear eye protection). This coming weeked, I'll face off the prepared plugs and start looking for a brazing rig. I plan to braze the plug to a KF40 flange, and possibly use a bulkhead clamp to connect the finished assembly to my vacuum chamber. Lesker and Duniway don't list bulkhead clamps in their catalog, but MDC does. It's a fairly simple way to connect a KF flange to a chamber with a flat surface, involving only hole drilling and tapping rather than welding a mating flange in place.
I did a vacuum run on my first chamber using a 0.1 torr baratron, which should be running in the middle of its operating range, so there should be less worry about zeroing error than with the 1 torr device I used last week. After about 1.5 - 2 hours of pumping, my bitty D1.6B pump got down to about 4.5 microns, though it was still creeping down very slowly. I then tried a larger D2A pump, which pumped down much faster, but hung up around 7.5 microns (this pump might need a tear-down). Next week, I'll try a longer pumping run, as I'm sure there is still water vapor coming off the walls of the chamber (and the vacuum hose), especially as it was a damp weekend.
- Re: Weekend Activities - Richard Hull May 16, 10:40 am