Vacuum Progress

March 30, 2018 at 1:25 pm

Today I’m grappling with a turbopump issue.  I’m using an NT 150/360 controller, and TMP 150 pump, both provided very generously be Provac Ltd.  They’re a great unit, but I think the Edwards RV3 backing pump is struggling to back them, and the system isn’t operating smoothly.


As noted, my backing pump is an Edwards RV3.  Gauges are an Edwards Pirani PK10 and a LEISK penning gauge for anything lower than 1 micron/0.001 mbar.  You can see the vacuum line in some pictures below, they show it in its final configuration – fusion ready.  (As long as the turbopump gets working).  It should even be possible to do fusion without the turbo-pump running, but deuterium consumption will be quite high.  I’d like to avoid that.


In the pictures you can see the Edwards RV3, with a valve on top and bellows going to the turbopump.  The turbopump itself is bolted to a conflat 6″ to 8″/DN100 – DN160 adapter on the 6″/DN100 side.  That connects to a fully variable throttle gate valve which is bolted onto an 8″/DN160 port on the chamber.  The Pirani and Penning gauge are seen attached to the tee on the chamber.



The green appendage to the chamber is a non-functioning mass-flow controller, connected to a Swagelok-adapting conflat flange.  The MFC is actually leak tight for vacuum when not powered, and is just blocking off the gas line port while I get the vacuum line working.