Building a Betatron At Home - Parts, Power Sources & Radiation Levels

[libbon]

Im not really sure if I am serious about making one of these like michio kaku for example. But i can't find too much info. on the internet about these, what are the parts of it like the electron gun, vacuum chamber, etc. And what do you use to power it, as in the element, a radioactive one, like carbon 14? And what do you use to power it as in electric induction? Also what is the level of energy in eV that harmful x rays, or any harmful radiation can be produced. and if anyone can post links to any diagrams of it would helpful too thanks.

Thank you

 

[arivero]

In any case, get hurry, because most of the cheap beta sources (TV sets) are now being retired from the market.

 

[Vanadium 50]

Building an accelerator is difficult and in many cases dangerous - even if it doesn't work. There are difficulties like getting a decent vacuum, and dangers like high voltage. I'm afraid answering a question like "how do I build one" is as irresponsible as answering "what's the best size fork to stick in my toaster".

 

[robert2734]

It will be easier to get programs for a VHStron.

 

[{~}]

you guys are so boring. I am totally excited to build a particle accelerator.

1. Go pick up a cathode ray tube down at the thrift store

2. Uhmmm

Seriously, a cathode ray tube is a kind of betatron. You can adjust the acceleration by adjusting the voltage. You can steer the electrons (cathode rays) with the nifty circuits that come with your newly bought, previously loved CRT.

The hard part is really to get a good vacuum (sorta like in a vacuum tube). You need what is called high vacuum which means that the mean free path of particle will be longer than the distance you need to cover.

What is the experiment you have in mind?

 

[Vanadium 50]

Seriously, a cathode ray tube is a kind of betatron.

Are you sure about this? A CRT contains an accelerator to be sure, but a betatron?

 

[libbon]

Well a betatron is just a cyclotron but it accelerates electrons instead of protons, the first one built in 1937 by Rutherford that had a 12cm diameter i think. But anyway, by a thrift store do you mean like an electronic store where to get the CRT?

I just want to make sure what i need this is directed to {~} because he seems as interested as I. So i need a vacuum chamber of sort, a CRT, and don't I need some sort of element to give the electrons, idk anything from like carbon 14 to hydrogen, what i mean is what do you need to supply the electrons?
I know I am writing quite a lot but one more thing i want to discuss is the safety, obviously there high voltage issues but that's not worrying me. I know as a fact that medical officials use betatrons in the hospital for treatments, meaning they use the radiation produced by betatrons. So should i be worried about the betatron emmiting x rays and then there's always the photoelectric effect.
Thanks so much.

 

[Vanadium 50]

Well a betatron is just a cyclotron but it accelerates electrons instead of protons,

Superficially they look alike, but the principle of acceleration is totally different.

I am afraid I am going to be direct here - if you don't know the details of how one works, you have no chance of building a working betatron. However, you do have a very good chance of injuring or killing yourself.

 

[arivero]

For reference, my TV set says 31.5 KVolt, and it is a huge one. I think smaller tubes were about 20KVolt.

Does it mean that the electron gets 31.5 KeV, or is it less?

 

[sylas]

Im not really sure if I am serious about making one of these like michio kaku for example. But i can't find too much info. on the internet about these, what are the parts of it like the electron gun, vacuum chamber, etc. And what do you use to power it, as in the element, a radioactive one, like carbon 14? And what do you use to power it as in electric induction? Also what is the level of energy in eV that harmful x rays, or any harmful radiation can be produced. and if anyone can post links to any diagrams of it would helpful too thanks.

You're getting some wise cautionary advice here which is well worth taking into account.

But on a more upbeat note, here are some concrete suggestions that won't hurt a bit!

If you have not already done so, try obtaining and reading Hyperspace: A Scientific Odyssey Through Parallel Universes, Time Warps, and the Tenth Dimension, by Michio Kaku. It has a brief account of his betatron which shows a couple of things... specifically that he started out with a lot of reading, and then by doing some simpler projects.

Later, in high school, I exhausted most of the local libraries and often visited the Stanford University physics library. There, I came across the fact that Einstein's work made possible a new substance called antimatter, which would act like ordinary matter but would annihilate upon contact with matter in a burst of energy. I also read that scientists had built large machines, or "atom smashers," that could produce microscopic quantities of this exotic substance in the laboratory.

One advantage of youth is that it is undaunted by worldly constraints that would ordinarily seem insurmountable to most adults. Not appreciating the obstacles involved, I set out to build my own atom smasher. I studied the scientific literature until I was convinced that I could build what was called a Betatron, which could boost electrons to millions of electron volts. (A million electron volts is the energy attained by electrons accelerated by a field of million volts.)

First, I purchased a small quantity of sodium-22, which is radioactive and naturally emits positrons (the antimatter counterpart of electrons). Then I build what is called a cloud chamber, which makes visible the tracks left by subatomic particles. I was able to take hundreds of beautiful photographs of the tracks left behind by antimatter. ...

Note above how much work Michio Haku put into learning about the relevant background, and that he also spent considerable time on other simpler projects first.

This extract then goes on to describe a couple of things about his subsequent betraton project, including spending a Christmas vacation winding about 22 miles length of copper wire, with the help of his long suffering parents. And then he repaid their support by blowing all the fuses in the house regularly when he ran the thing. And as it turns out, the main achievement he describes is being able to produce an enormously powerful magnetic field.

I would recommend you do the same as Michio Kaku; start out with a cloud chamber. (Assuming you have not already done so? Link to wikipedia.)

You will find this is easier, cheaper, faster, and probably will be much more interesting for what you can do with it.

There have been several threads already at PF on making a cloud chamber. See old threads at [thread=138945]Cloud Chamber Experiment[/thread] and [thread=134829]Building a cloud chamber[/thread], or search for others. There is also a new thread just started up, I notice! [thread=384082]Need help making a cloud chamber...[/thread].

You can find detailed instructions all over the web if you google for them! Here's a good one: How to Build a Cloud Chamber. There's also a nice clear video on how it could be done:


The video above is showing tracks from alpha particles. There's scope here for all kinds of extensions. It would be interesting to see if you can set up magnetic fields to induce the spiral patterns often seen in books, or get tracks from other particles. Can a home made cloud chamber pick up beta particles (electrons) or beta⁺ particles (positrons)? I don't know but others here might!

Good luck -- sylas

 

[libbon]

Thank You sylas that's a lot of useful info, i will really take all of it into consideration, you put me on the right track now,im going to try to get that book, as I am already a fan of michio kaku as i have already read his other books. And hopefully i can eventually start with making a cloud chamber.