News Archive

Decision on a Pre-accelerator Design

Tuesday, September 23, 2008 by Raymond Jimenez

I've decided to go with a betatron as my pre-accelerator. It's a relatively simple design, requiring less math than an RF electron linac, and it's much more compact.

The only problem with a betatron is that the vacuum chamber must be non-conductive (many in the past used silvered glass chambers), so I might opt to make my own vacuum chamber. Scientific glassblowers are relatively rare, so I would need to find somebody who would be willing to contribute substantial amounts of time.

Other than the vacuum chamber, the iron return yoke needs to be designed and made. While it's not a high frequency yoke (usually about 180Hz), it needs to be made out of laminate so that eddy currents don't eat up the power. I can't work with iron here, so I'll also need to find a willing transformer company.

Finding information about betatrons is proving difficult; the term "betatron" is more in use as "betatron oscillations", and betatrons have been long surpassed in the science world by RF linacs for higher energies.

Independent study approved

Sunday, September 14, 2008 by Raymond Jimenez

My independent study was approved, and things have gone well. I met with Frank Porter this past Friday; he had me thinking about pre-accelerator designs. I need to investigate what's the best option; I can build a linac, microtron, or betatron.

The best option is probably to build a pre-accelerator that can get up to the full 5MeV that the ring requires; that way I won't have to worry about crossing resonance lines etc. in the ring itself, as the electron energy and tune will remain constant.

Building the pre-accelerator itself (5MeV) will be a challenge, probably only completed sometime next calendar year.

An advisor and independent study

Saturday, September 6, 2008 by Raymond Jimenez

I've submitted a proposal to my school's independent study program to see if I might get credit for this project. I'm going to put in a lot of work over the next year, so I might as well get credit for it.

I've also found a Caltech professor, Frank Porter that's willing to help out as an advisor.

Working on the design

Wednesday, August 27, 2008 by Raymond Jimenez

I'm trying to come up with a design that's not too far from my ideas on the design page, complete with magnet specifications and stability conditions etc.

I probably won't be done for at least the next month, due to the fact that school's started.

A good set of references

Monday, August 25, 2008 by Raymond Jimenez

I came upon a couple of good links searching for "compact synchrotron design."

Compact Synchrotron Light Sources by Ernst Weihreter is helpful since it talks about emperically proven compact synchrotron light source design. It's not that specific to high-current, high-energy devices since he also talks about the theory and general issues that come up in these things.

It turns out there have been several small synchrotron light sources built (though all in the 100+ MeV range). The most interesting were the AURORA light sources, which came in several varieties, the smallest of which being a 1m weak-focusing ring. (It looks really intimidating to build, even if it's only a small 1m ring.)

There is also a paper submitted to the European Particle Accelerator Conference in 1990 that details most of the compact synchrotrons then in existence.

Additional input and feedback from the fusor forums

Friday, August 22, 2008 by Raymond Jimenez

I posted on the fusor forums about this project and received many helpful comments, particularly from Carl Willis. A tip from Carl and a little bit of research lead me to think a more feasible design for the preaccelerator/injector might be a classical microtron. The SESAME preaccelerator uses a microtron, so it's been done in practice. However, the RF power bit will need to be worked out.

Gotta teach people

Thursday, August 21, 2008 by Raymond Jimenez

...so that this project doesn't face an uproar.

Working on the website, part II

Thursday, August 21, 2008 by Raymond Jimenez

I've expanded the design section to list what I have in my head at the moment. In the next week or so I should be attacking textbooks and finding formulas so I can verify all of these things that I've said. That means pretty graphs and formulas and even more explanations.

I realize that this page isn't so useful for those who are just wandering by: it's really dense with jargon all over the place. I'm in the process of writing an introduction and explanations that'll explain this entire shtick. I want to make sure everybody can understand what I'm doing.

Oh, and there are places that are unfinished: the references and links pages are pretty scrawny. I will get to them as soon as I can, but they're relatively low on the priority list.

Working on the website

Wednesday, August 20, 2008 by Raymond Jimenez

The majority of this website doesn't exist yet, so I'm trying to fill in the blanks. Along the way I'd like to figure out how to use LaTeX to print out formulas really easily so I can drop them on a page with minimal pain. (Something like a private mathbin might work.)

I'm trying to get in contact with additional professors; more is always better. I'm currently talking to somebody in HEP at Caltech.

I'm shooting for an entirely unreasonable operation date of June 2009. If the project drags on for a couple of years, I'll need to figure out how to either transport it to college or transfer responsibility of it, neither of which looks appealing.

The three main divisions of labor that I'm looking at are:

  • Designing the accelerator
  • Finding funding/lab space
  • Obtaining support/advice

Lots to do in so little time. Please send me a line if you want to help!

A website appears

Tuesday, August 19, 2008 by Raymond Jimenez

Website is up. Currently figuring hard-line limits on ring diameter given possible magnet strengths.