HUGE Vacuum chamber

[Kuba Anglin]

Hello,

I recently organized a meeting with the chair of the nuclear engineering department at UC Berkeley, Karl A. van Bibber, to discuss the fusion reactor project that I plan to complete with my brother. When the meeting started, we talked about the recent projects my brother and I completed. Professor van Bibber then suggested that we go see the lab. We followed him down many flights of stairs beneath the ground and then he opened the door to a massive laboratory; the ceiling was 3 stories high. He described in detail almost every ongoing experiment. There were vacuum chambers on most tables, high voltage power supplies lining the walls, tanks containing various gasses, an insane amount of pipes and tubes hanging overhead, and a large concrete bunker that once housed a nuclear reactor. The experience was amazing. After the tour, he took us back to his office and we discussed our proposed project in more detail. We talked about our planned experiments using a fusion reactor. I then mentioned that we were in search of many parts; including a vacuum chamber. He thought for a moment and then told us that there was a large vacuum chamber in the basement of the building that he needed to relocate. To our utter disbelief, he offered that we take it and use it for our experiments. The meeting was scheduled for 40 minutes, but ended up lasting 90. He allowed us to take some pictures of the chamber:

Professor van Bibber and I before I could regain my composure.


A more serious photo.


My twin brother and I with the chamber.


The tags on the chamber.


The meeting was about two weeks ago, but just yesterday, Professor van Bibber told us that all the paperwork was done and that we can now take the 1000 pound chamber. This chamber is by far the biggest I have seen in terms of amateur fusion reactor chambers. Any comments or advice regarding a chamber of this magnitude used for fusion would be highly appreciated. Also if anyone knows about the type of this chamber in general, please share your knowledge. Professor van Bibber said that the chamber may contain a turbomolecular pump in the bottom cavity or some other expensive piece of machinery. Here is Professor van Bibber's page: https://www.nuc.berkeley.edu/karl-van-bibber.

Regards,
Kuba Anglin

[Scott Moroch]

Kuba,

Wow! That is some chamber! It sounds great that you have made a connection on the University level. However, based on all of the fusors I have seen on this site, I must say that if I was in your position and first starting my fusor, I would not use a chamber that large. What are your goals with that chamber? Do you hope to conduct any experimentation? If so, can it be done with a smaller chamber? I think often times the expectation is that a larger chamber will yield higher results, however this has been proven to not be true. Often times a larger chamber only means- more expensive and the same results as a smaller chamber.

I am only bringing this up because it will take a hefty vacuum system to pump that chamber down. Assuming the best situation and the chamber does have a turbo pump at the bottom, that chamber will still require a very powerful mechanical pump. I really hate to rain on the parade because the chamber does look awesome, however I am sure others will agree that this chamber will be difficult to work with.

Regardless I wish you the best of luck with your project.

Scott Moroch

[Jerry Biehler]

You really dont want this chamber. Way, way too big and you will end up needing a rigger or something to move it and it will cost a lot to do that, $500 to $1000 for a truck and a couple riggers. This is NOT something you want to move by yourself. One goof and it can fall over and crush you.

You will need a massive pump, I have something similar in volume and I use a large rotary pump package with a roots blower to get it down to pressure.

If you do try to do fusion you will waste a massive amount of D to get it to pressure. And making modifications to end plates and stuff will be very expensive.

Its a nice offer but you really should pass on this one. It is way past what is feasible.

[Richard Hull]

All the negatives have been noted. Still, it is free provided you can get it home. With this baby, you will learn a lot about vacuum!

Richard Hull

[JoeBallantyne]

If the label in your last picture is correct, it looks like there may be a very large turbo pump already attached to the chamber.

The problem will be getting the correct controller, and whether the pump works.

But if that really is a 3500l/s turbo pump, and it works, it is a VERY expensive piece of equipment.

Joe.

[JoeBallantyne]

It looks like that chamber might be a 20" dia 6 way cross. I've been watching vacuum chambers on e-bay for a very long time. I've never seen one like that. I saw a much smaller 6 way cross go for $5000 almost immediately. If there really is a working turbo on the bottom that would be a steal on ebay for $10,000 total. Especially if you split the turbo and the chamber into 2 separate lots.

At a minimum you could turn around and sell it, and use the funds to buy everything you need in smaller form.

Rent an Enterprise Commercial Truck with a 6'x8' liftgate (the 6' length is the most important dimension, not the width), roll it on (looks like it is on big casters), lift it up, secure it, drive it home, and roll it into your garage.

Turning down a gift of many thousands of dollars isn't real smart. (IMO)

Joe.

[JoeBallantyne]

A new pump with less capacity (3200l/s) from the same manufacturer is available now on e-bay for a mere $17,000.

http://www.ebay.com/itm/Oerlikon-Leybol ... 540a928eb9

Like I said. Large turbos like the one on the bottom of that vacuum chamber are very expensive.

Joe.

[Tom McCarthy]

Kuba,

One thing with Joe's advice that mightn't be a good idea is Professor Van Bibber. As you've already met with the Professor and he seems to be quite happy to assist you, I'd say you're going to be asking for his help/advice in the future. If this is the case, I doubt straight selling the chamber he's just given to you for a quick buck is going to buy you any favours - I know the academics I'm working with wouldn't appreciate it!

I'd echo what Scott, Jerry and Richard have already said, but I think they've given enough on the topic already...One thing to note is you might be able to just take the turbo pump, I'm sure that would be a very nice piece for a smaller chamber if you could isolate it.

Best of luck,
Tom

[Andrew Robinson]

You can always be upfront about it. Let them know that you wont be able to use it. I can assure you that professor is already well aware of the challenges that using that chamber will present. Old equipment like that sitting around labs generally just takes up space and professors love getting it out of the lab. Now generally there is an official process to have equipment removed, tracked, and disposed of or sold off properly by the University. The equipment most likely does not belong to the professor directly unless he personally funds his research (which is highly unlikely but not unheard of). At any rate, if you are up front with you intentions that perhaps you could sell the chamber to help fund the project I'm sure he would not mind. Honesty is the best policy. Tom is correct though. I wouldn't take it off his hands and part it out without them knowing about it. Good luck!

[Frank Sanns]

Do not be afraid of a large chamber. They still pump down but it just takes a little longer.

I have a 10" 6 way cross that is around 20 liters and a larger converted vacuum oven that is around 300 liters. Pump down time to under 1 torr with a Welch 1402 is under 5 minutes for even the large chamber. After that I switch on a 3 inch diffusion pump that is close coupled with the chamber or a modest turbo pump depending on the work that I intend to do. Within half an hour, both chambers can be at fusion pressures.

Keep the distances between the chamber and the high vacuum pumps to be as short as possible. The pressures used for fusion are not really all that low and conduction is not really a big issue as long as you do not get things too far apart.