How do ion sources in cyclotrons work?

[mike_gamma]

I've been learning about cyclotrons recently and have trouble understanding how the ion source works. I have done some research and found that duoplasmatrons are some forms of ion sources but i don't think that's legit. I also found something called RF ion sources, but not sure how they work. I also would like to know how to build one or at least if it is possible at a high school level.
Thank you.

 

[bobob]

Ion sources for cyclotron work by placing ions in the center region. That is done in one of two ways. You can insert a source from above or below the center of cyclotron. In this case, your source is going to be either a gas that gets ionized by high voltage or a solid source that gets ionized by an arc. There will be an electrostatic element off center somewhat to pull the ions into the cyclotron. The other way is by axial injection. You create the ions in a source located either above or below the center of the cyclotron first. Then the ion beam you create is accelerated a little and focussed onto an electrostatic mirror called an inflector, which bends the beam 90 degrees into the cyclotron.

Well, you could build one for a high school project if you are a lot wealthier than the average high school student and have access to a machine shop. :) You are looking at 5k-10k for a fairly simple one (if you buy used equipment at a good price). The source itself would not be too expensive, but the ancillary equipment needed to make it work includes vacuum pumps, high current and high voltage power supplies. A very nice ion source is called MeVVA (Metal Vapor Vacuum Arc). Another would be an ECR source (Electron Cyclotron Resonance), but that would be way over budget and skill set. :) You should be able to find a lot of information on both of those. The MeVVA source is simple conceptually and relatively inexpensive, the key word being relatively.

 

[mike_gamma]

Thank you. Yeah, no i don't think ill afford something like that obviously, i was thinking of trying to make a cheap affordable one with minimum equipment, maybe rent some of the equipment. I was also thinking of using Americium as ion source, but someone told me that that would generate a beam with a very low intensity. What do you think? I was thinking of making a cyclotron for a total cost of $300 to $400 and work to be able to afford it. I don't know, have you got any advice or guidelines which i can use like a book or a website? Thank you again!

 

[berkeman]

I was thinking of making a cyclotron for a total cost of $300 to $400

Welcome to the PF, Mike.

the ancillary equipment needed to make it work includes vacuum pumps, high current and high voltage power supplies.

Do you understand what Bob was saying about the supporting equipment and technologies involved? What is your background working with high vacuum? What is your background working with high voltages? What is your background in radiation shielding? Before you set out to build a particle accelerator (even a relatively small cyclotron), you need a lot of experience in those things, or you are really a danger to yourself and others.

A better goal would be to get a position as an intern in a university lab that is working on accelerator physics. Are you in university now?

 

[mike_gamma]

Welcome to the PF, Mike.

Do you understand what Bob was saying about the supporting equipment and technologies involved? What is your background working with high vacuum? What is your background working with high voltages? What is your background in radiation shielding? Before you set out to build a particle accelerator (even a relatively small cyclotron), you need a lot of experience in those things, or you are really a danger to yourself and others.

A better goal would be to get a position as an intern in a university lab that is working on accelerator physics. Are you in university now?

No I'm just an excited 15 y.o. kid who likes physics and wants to learn. How much do you think a diy cyclotron would cost? I do not have any experience and have no access to any equipment tbh and the closest uni is really bad and will not have any equipment. I don't have enough money to spend on this project but still want to accomplish, and i will try. I will try not to put anyone in danger lol :) Is it possible to get an internship somewhere at my age? And what kind of stuff what i have to do?
Thank you.

 

[phinds]

How much do you think a diy cyclotron would cost?

By focusing on cost, you are ignoring the danger warnings that you have been given. It is clear that you do not even begin to have the experience that such a project would require to be done successfully.

Read about them some more and about the ancillary equipment that is required and you'll begin to get the picture.

 

[berkeman]

No I'm just an excited 15 y.o. kid who likes physics and wants to learn. How much do you think a diy cyclotron would cost? I do not have any experience and have no access to any equipment tbh and the closest uni is really bad and will not have any equipment. I don't have enough money to spend on this project but still want to accomplish, and i will try. I will try not to put anyone in danger lol :) Is it possible to get an internship somewhere at my age? And what kind of stuff what i have to do?
Thank you.

Good for you, enjoying science and physics and wanting to do some projects to learn more. That's a great start for you, and a great path that you are on. Keep it up!

But at least for now, even a small particle accelerator will have to wait until you have more learning and experience under your belt. You can probably tell by our replies so far that there are some significantly dangerous issues that you would need to deal with in the development of a small particle accelerator. You can do some Google searching and reading about the first small cyclotrons to get an idea of all of the things that are involved.

Instead, try to think of other fun projects to work on that teach you a lot and are less dangerous in terms of requiring high vacuum, high voltages and radiation shielding. What other project ideas do you have? What are some of your interests? Robotics, electronics, radios, phone Apps, etc.?

 

[BvU]

How about a van der Graaff generator ? Plenty tension !

 

[anorlunda]

Mike, you'll like this article https://www.symmetrymagazine.org/article/august-2010/the-do-it-yourself-cyclotron. Maybe you could join that society of amateur cyclotron builders. But it is a bit out of reach for your budget. From the article:

There are no guidebooks or instruction manuals, and if you bought the raw materials off the shelf, it would cost around $125,000. On average, amateur cyclotrons take two to three years to build. And while it would drive some people crazy to build their own car and never drive it, in the 80-year history of amateur cyclotron building, only occasionally have the finished products been used for experiments or in education: Yuly says, “That’s not why we build them.”

There are many great DIY projects within your reach. I hope you find one that interests you.

 

[berkeman]

Plenty tension !

You Europeans talk funny.

(Luckily, the OP is from Europe too)

 

[mike_gamma]

By focusing on cost, you are ignoring the danger warnings that you have been given. It is clear that you do not even begin to have the experience that such a project would require to be done successfully.

Read about them some more and about the ancillary equipment that is required and you'll begin to get the picture.

No, I'm not starting now. I was planning on starting it next year. Right now I'm just going to buy some books and read up on it, especially in the summer. You're right, i don't know much about this stuff, which is why i really want to learn:)

 

[mike_gamma]

Good for you, enjoying science and physics and wanting to do some projects to learn more. That's a great start for you, and a great path that you are on. Keep it up!

But at least for now, even a small particle accelerator will have to wait until you have more learning and experience under your belt. You can probably tell by our replies so far that there are some significantly dangerous issues that you would need to deal with in the development of a small particle accelerator. You can do some Google searching and reading about the first small cyclotrons to get an idea of all of the things that are involved.

Instead, try to think of other fun projects to work on that teach you a lot and are less dangerous in terms of requiring high vacuum, high voltages and radiation shielding. What other project ideas do you have? What are some of your interests? Robotics, electronics, radios, phone Apps, etc.?

Yeah, i was thinking of building a computer and messing around with electronics and stuff this summer like last year, but i was also thinking of building something more to do with particle physics. I guess i can wait a few years:) Thanks anyways

 

[mike_gamma]

Mike, you'll like this article https://www.symmetrymagazine.org/article/august-2010/the-do-it-yourself-cyclotron. Maybe you could join that society of amateur cyclotron builders. But it is a bit out of reach for your budget. From the article:There are many great DIY projects within your reach. I hope you find one that interests you.

Yeah i stumbled across this article and it was very informative on cyclotrons, and i actually got in touch with Mark Yuly, one of the professors who conducted that project and was asking him about diy cyclotrons. He was just sending me pdf files which were interesting and also livingston's work on the first cyclotron. Thank you :)

 

[BvU]

You Europeans talk funny.

(Luckily, the OP is from Europe too)

suspense?

 

[anorlunda]

i actually got in touch with Mark Yuly, one of the professors

Here on PF, we are usually wary about young people who want to do DIY projects that may be dangerous. We advise them to seek the support of a club or group with similar interests, rather than asking strangers on the Internet technical questions. It sounds like you are already following that advice on your own. Good for you. I hope those contacts stimulate your interests.

At GE in Schenectady, NY we used to have a cyclotron in building 37 that sat unused for several decades. They got rid of it in the 90s, but I don't know if it was demolished or if they sold it in a garage sale. Perhaps professor Yuly might have heard that anecdote. (ping @jedishrfu )

 

[mike_gamma]

Here on PF, we are usually wary about young people who want to do DIY projects that may be dangerous. We advise them to seek the support of a club or group with similar interests, rather than asking strangers on the Internet technical questions. It sounds like you are already following that advice on your own. Good for you. I hope those contacts stimulate your interests.

At GE in Schenectady, NY we used to have a cyclotron in building 37 that sat unused for several decades. They got rid of it in the 90s, but I don't know if it was demolished or if they sold it in a garage sale. Perhaps professor Yuly might have heard that anecdote. (ping @jedishrfu )

This is my first post for guidance in something like this, up until now i had been doing my own research but now it's gotten to the point where i have so many questions with which i get stressed about and have no one to answer them. My physics teacher is boring and has no interest in the subject, so i can't really consult her on anything. Thanks anyways:)

 

[anorlunda]

We certainly want to encourage your curiosity and initiative. The advice to find local groups applies to DIY -- potentially dangerous DIY. For regular questions on science and engineering, PF is an excellent place to do that.

Re DIY: It is likely that there is some club or group local to you that can provide better assistance than we can. Ask around for a HAM radio club. Even if you are not interested in HAM, the club will have tech fans who can direct you to other local resources. Then again, many people find HAM radio great fun.

 

[Vanadium 50]

If you try and build a cyclotron, the odds are substantially higher that you will injure yourself or a loved one than that your cyclotron will work.

Normally the mentors close these threads. I'm not sure why they are keeping this one open, because the discussion is tantamount to discussing the proper fork to stick in a toaster.

Whenever someone says "I want to build a cyclotron", it is a red flag that they are too inexperienced to do so. Apart from risks like high voltage, vacuum, high current, x-rays and (if it manages to work) radiation and licensing, cyclotrons are not the simplest accelerator to make. People with enough knowledge to make them work know that this is not a good starting point.

$300 won't even be enough to get a working cyclotron shipped to your door. You need 100x-1000x that much to actually build one.

One thing you could start on is the design of one. I will tell you right now that if the magnet isn't right, the cyclotron will not work. So, what does your magnet look like? How much does it cost? How much does it weigh? Where do you plan to put it, and how do you get it there?

 

[anorlunda]

Normally the mentors close these threads. I'm not sure why they are keeping this one open, because the discu

Read the whole thread and you'll see that we are not giving dangerous advice.

 

[Vanadium 50]

No, you are not giving dangerous advice, but you are giving advice on an intrinsically dangerous project. (And ineed, your advice of "try another project - like radio" is good)

 

[mike_gamma]

If you try and build a cyclotron, the odds are substantially higher that you will injure yourself or a loved one than that your cyclotron will work.

Normally the mentors close these threads. I'm not sure why they are keeping this one open, because the discussion is tantamount to discussing the proper fork to stick in a toaster.

Whenever someone says "I want to build a cyclotron", it is a red flag that they are too inexperienced to do so. Apart from risks like high voltage, vacuum, high current, x-rays and (if it manages to work) radiation and licensing, cyclotrons are not the simplest accelerator to make. People with enough knowledge to make them work know that this is not a good starting point.

$300 won't even be enough to get a working cyclotron shipped to your door. You need 100x-1000x that much to actually build one.

One thing you could start on is the design of one. I will tell you right now that if the magnet isn't right, the cyclotron will not work. So, what does your magnet look like? How much does it cost? How much does it weigh? Where do you plan to put it, and how do you get it there?

Dont worry, i have no intention on carrying out such a project with high risks and dangerous consequences because i honestly value my own life :), and because i have no money to spend, i can barely buy a few physics books! I think ill stick to reading and understanding the dynamics of a cyclotron and improve my design. I will also check out the magnet. Thank you very much for the advice, see ya!

 

[geoelectronics]

I also would like to know how to build one or at least if it is possible at a high school level.
Thank you.

If you want to build a demonstration device, such as for a Science Fair, why not use Beta particles (positive or negative, or both) and build a quarter wave Beta Bendatron instead. Cost should easily be within a 400 USD budget and shows the principles clearly. Later you could add drift tubes to demonstrate acceleration.
If you are in USA, using Americium-242 for anything outside its General License exemption is illegal. There are many other legal radioisotopes that are available to anyone ( US NRC Schedule B Exempt Quantity Sealed Sources ).
You are thinking in the right direction, and such thoughts can lead to a rewarding career choice later.

Citations available upon request.
Thank you.
George Dowell