Uhv Definition and 12 Threads

I recently realized a quite long (4.5 m) tube for ultra high vacuum in alluminium. Unfortunately in the realization a terrible error has been made... The internal surface has been anodized! I know that such treatment horribly enhance the outgassing rate... I read over the net that in principle...

Hi there, I have a small, few liter UHV chamber that frequently needs to be vented and rebaked. I want to shorten my bake time, so I’ve obtained a glove box to allow me to vent, work and close back up under inert gas. i’m curious if people have a preference between Argon and dry Nitrogen. I...

Hello all, I have a Varian M4 diffusion pump that has a 6 inch diameter opening at the top, is it okay for me to connect that to a reduced size opening like just 2 or 3 inches diameter so that I can use a smaller valve? I am only trying to pump down a cubic foot or two sized chamber. I am...

Can I make diffusion pumps from aluminum? I am going to create parallel connected diffusion pumps for many UHV purposes. I see that aluminum that is treated to prevent outgassing is used for UHV valves, chambers, and reactors. I'd like to know what temperature diffusion pumps boil their...

If using diffusion pumps (2 or 3 in series) to achieve ultra high vacuum, how do you hook them up together, for example adding them onto a system like in the provided picture? Would you use T-connectors to put them all on the same input and output valves or would you have valves for each pump?

Homework Statement What is the mean free path of an N2 molecule in an ultra-high-vacuum chamber at a pressure of 10-10mbar? Homework Equations λ=1/(√2)nσ number density n, collision cross-section σ p=nkT pressure p, temperature T σ=πd2 d molecular diameter The Attempt at a Solution...

What are the reasons (advantages) for using nitrogen when venting vacuum systems?

I'm trying to figure out some things regarding leak rates. I have a system which is constructed to adhere to UHV standards (total leak rate < 10^-10 Torr*L/s), baked out and evacuated to 10^-9 Torr, and then backfilled to about 600 Torr with N2 and Xe. So, there's a leak of air from the outside...

Cannot seem to find such a connection. The UHV vacuum sits around 1x10-8. The fitting needs to be rated for cryo temps. Thanks

Knife edges on the edges of flanges with a maleable material gasket like copper is often used for creating UHV chamber environments. For UHV view ports, typically say quartz or some other material, how is the UHV seal accomplished? Is it the same mechanism? E.g. knife edges machined on...

I recently had some discussions about the use of aluminum in a ultra-high vacuum (UHV) apparatus. There seem to be those who believe Al is good in UHV and those who believe it is bad. I was wondering if anyone has some authoritative source for information on this. Those who believe it is bad...

I got a problem with ultra high vacuum system, and would like to know some advice. A UHV chamber just moved to the lab, and I cleaned it with aceton, put the ion pump indside and sealed all the ports, and I've been pumping the chamber for like 3-4 or 2-3 weeks. I leak tested it by a helium...