Fusor vacuum and system overview
here are a few pics of the high vacuum system and the main chamber. to the left is an RGA head i hope oneday to find the controller fore. in the midle is the turbo punp and UHV valve and on the right is the chamber. the chanber is something of a prototype cobbeled together from an assortment of parts liberated from various places. all the seals in the UHV part (not the chamber) are copper gasgeted conflats. the chamber has a higgeldy-pigeldy mix of conflats and non-standard o-ring seals. luckaly, KJLC have a very good selection of o-rings :)
the virw port is homemade from a conflat blank and a (saphire?) disk salvaged from a UV spec i found in a skip :) the transparent disk is sealed into a recess machined in the conflat with a high grade aquarium silicone sealent (HA6) i have also used this sealent elseware to seal some leaks on the chamber and it seems adaquate for vacuum work. i may revise this oppinion when i get closer to fusion though ;)
this nexp ic ahows my attempts to seal some anoying ports that are just unnessasery. such is the nature of scavanged stuff :/
another pic. spot the apiezon grease :) it always amuses me when i use it, its so expensive, i must use about 50p worth per o-ring :(
the vertical copper pipe is an earth. it goes through the concrete flaw dirrectly into the clay.
the low vacuum system. a belt driven single stage edwards. the thing above the pump is an air admitance valve which isolates the rest of the vacuum system from the pump, and allowes air into the pump then the power is removed. this prevents pump oil being sucked up into the vacuum system. the shiny silver cilinder is a molecular sive full of zeolite. it adsorbs oil and moisture vapour.
below are the results of my battle with non-standars scavanged vacuum fittings.
And the results of all this:
A nice though slightly diffuse plasma. nichrome grid glowing red.
Unfortunatly there is where the story stops. Life got in the way, moved out of house, no space for fusors any more. all is not lost however the parts are all carefully packed away in storage and when suitable facilities become available the saga will continue!