Search found 673 matches

by Andrew Seltzman
Sat Dec 02, 2017 12:09 am
Forum: Please Introduce Yourself
Topic: Greetings from NoVA
Replies: 2
Views: 112

Re: Greetings from NoVA

Hi Josh, Welcome to the forums. I would recommend the 110V version of the pump, both of the ones you linked to are 208V https://www.ebay.com/itm/Pfeiffer-Duo-1-5A-Dual-Stage-Rotary-Vane-Vacuum-Pump-110V-50-60-Hz/132414362897?epid=691772422&hash=item1ed482d511:g:9j0AAOSwonBZ9PCm https://www.ebay.com/...
by Andrew Seltzman
Tue Nov 28, 2017 3:04 am
Forum: New User Chat Area
Topic: Oil Diffusion Pump Questions
Replies: 10
Views: 364

Re: Oil Diffusion Pump Questions

It's almost certainly a CVC PMCS-2 set up for air cooling

http://mmrc.caltech.edu/PVD/manuals/CVC ... %20PMC.pdf
by Andrew Seltzman
Thu Nov 23, 2017 4:18 am
Forum: The Trading Post
Topic: WANTED OIL DIFF PUMP/TURBO PUMP
Replies: 8
Views: 231

Re: WANTED OIL DIFF PUMP/TURBO PUMP

Make an offer by message to the seller of the turbo first, they may be willing to come down in price.
by Andrew Seltzman
Wed Nov 22, 2017 5:30 pm
Forum: The Trading Post
Topic: WANTED OIL DIFF PUMP/TURBO PUMP
Replies: 8
Views: 231

Re: WANTED OIL DIFF PUMP/TURBO PUMP

Try making them an offer, they might take it.
by Andrew Seltzman
Wed Nov 22, 2017 5:28 am
Forum: The Trading Post
Topic: WANTED OIL DIFF PUMP/TURBO PUMP
Replies: 8
Views: 231

Re: WANTED OIL DIFF PUMP/TURBO PUMP

Turbo/drag hybrid $600 with controller, free shipping and right of return if inoperative:
https://www.ebay.com/itm/Pfeiffer-Split ... 1438.l2649
by Andrew Seltzman
Sat Nov 04, 2017 1:02 am
Forum: Vacuum Technology (& FAQs)
Topic: Fixing a leaky SS-4H valve?
Replies: 11
Views: 317

Re: Fixing a leaky SS-4H valve?

The swagelok SS-4H is a top end, all metal valve, with through leak rates at 4e-9 cc/s when closed for a new valve. Used valves on ebay typically have leak rates still in the 1e-7 cc/s or lower. Eventually the seat does wear out; due to the welded construction, there is really no way to fix the valv...
by Andrew Seltzman
Wed Nov 01, 2017 2:12 pm
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Anode layer ion source. Operation pictures
Replies: 61
Views: 18846

Re: Anode layer ion source. Operation pictures

Finn, The original reason for the vacant hole was to allow a gas feed to come in through the back of the ion source, also the first ion source prototypes were hand machined, so the looser tolerances made the fasteners more likely to bind with the lower machining tolerances; only having three mounts ...
by Andrew Seltzman
Wed Nov 01, 2017 12:21 am
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Anode layer ion source. Operation pictures
Replies: 61
Views: 18846

Re: Anode layer ion source. Operation pictures

I have recently developed a technique to allow narrow pulse width, high current ion pulse generation with reduced jitter and delay in an anode layer ion source by adding a keep alive electrode into the discharge channel. I have a patent pending on this design, and a paper on this technique under rev...
by Andrew Seltzman
Fri Oct 27, 2017 4:13 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Increasing the useful life of bubble detector tubes
Replies: 13
Views: 575

Re: Increasing the useful life of bubble detector tubes

I wouldn't say that I use may tubes very regularly, I'd estimate 10-20 times a year. I do however, keep my detectors stored within the aluminum tube at a relatively constant room temperature. I store them in a horizontal position (fairly sure this is irreverent). The failure mode that I've almost al...
by Andrew Seltzman
Thu Oct 26, 2017 4:57 am
Forum: Vacuum Technology (& FAQs)
Topic: What in the world is MKS doing here? (ion gauge that works at atmospheric)
Replies: 7
Views: 275

Re: What in the world is MKS doing here? (ion gauge that works at atmospheric)

The catch is accuracy, the gauge specifies +-50% error at high pressure (>10torr). It's only using the "enhanced arc" to turn the ion gauge on/off in inverted magnetron mode. I's assume it's using some sort of current limited corona or "ion breeze" current sensing at high pressure.