# Some help with calculations please

1. Jul 12, 2008

### Cups

Some help with calculations please :)

So my friend Ryan is building a home made cyclotron particle accelerator. I'm rather interested in building one of my own, but fear I lack the technical know-how and mathematical practice to do so just yet. I asked him how he is building it(on facebook, heh) and he replied as such:

"well first off I am modeling it off of a cyclotron .... its taking two D shaped plates and having an alternating current go from each plate what i then do is calculate the frequency of a particle * ion* under the influence of a magnetic field... which is created between these two slolinoids they are producing about a 4 or 5 Tesla field... try to calculate is with these parametiers and see what you get with n( turns) = 3400, I = 5, L=.1(meters) with a magnetic core of iron with a K of 200 .... tell me what you get and I will explain more lol we can have a lil fun exciting challenge with this lol ttyl im going to eat dinner"

I feel his response is slightly unclear, but I don't care to ask him to elaborate on facebook. Would somebody help me interpret the symbols and units and brief me on any formulas I may need to calculate the frequency of the ion?

That would be a big push in the right direction.

2. Jul 12, 2008

### marcusl

Re: Some help with calculations please :)

Hi Cups,

Welcome to Physics Forums! I don't like to discourage budding scientists, but I'm afraid this is not a beginner project. In addition to a solid background in physics, math and electrical engineering, you'll need practical skills in magnetics, high vacuum systems, high power radio-frequency electronics, radiation shielding and particle detection, to name a few. As just one example, it is extremely difficult to design a 5T electromagnet. This will be large and heavy, require water cooled coils, and require a very high current power supply with extremely good stability.

I suggest that you set your sights on a smaller scale to start with (maybe a van de Graaff generator?), and work up to university-sized projects as your skill levels and physics knowledge increase.

EDIT: Cyclotrons are very cool! Wikipedia has some information if you'd like to learn more:
http://en.wikipedia.org/wiki/Cyclotron

Lawrence Berkeley Labs in California has a great museum, if you happen to live in the Bay Area, that includes parts from the first cyclotron (invented by, naturally, Lawrence).

Here's some early history.
www.lbl.gov/Science-Articles/Archive/early-years.html

They still have a cyclotron at the lab
http://cyclotron.lbl.gov/index.html [Broken]

Last edited by a moderator: May 3, 2017
3. Jul 13, 2008

### Cups

Re: Some help with calculations please :)

Hello, and thank you for the welcome!

I could have anticipated the difficulty in the project, Ryan is going to be a senior Physics/Astronomy/Mathematics major this year and I am just beginning my freshman year in the fall. I read the wiki on the Cyclotron, do you have any information about the Van de Graaff generator? Perhaps I could do that. Thanks ^.^

4. Jul 13, 2008

### marcusl

Re: Some help with calculations please :)

Sure, this one is within reach and there are many resources available. Scientific American used to run articles called "The Amateur Scientist" that gave excellent instructions on how to build equipment. Scroll down to Electrostatic Generators on this page, then you can find the articles at your university library:
http://amasci.com/amateur/sciamdx.html"

There seem to be dozens of web pages as well. Just google "how to build van de graaff" and "homemade van de graaff" and pick what you like. Have fun, and come back to tell us how it turns out!

Last edited by a moderator: Apr 23, 2017
5. Jul 13, 2008

### OAQfirst

Re: Some help with calculations please :)

I first read this as "building a home made of a cyclotron particle accelerator." Now that would have been interesting.

"So, where do you live?"

...

6. Jul 13, 2008

### Astronuc

Staff Emeritus
Re: Some help with calculations please :)

If one's friend is referring to the solenoid design, then this would apply.

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/solenoid.html#c2

See this for a discussion of the cyclotron

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/cyclot.html

Depending on the cumulative particle energy with electrons or otherwise, one must be careful of the radiation (UV, X-ray/gamma) emanting from the cyclotron and target. Shielding is necessary, and one should not be near the cyclotron when it is operating, and ferromagnetic objects must be kept at the appropriate distance. B = 5T is a strong field.

7. Jul 14, 2008

### Ouabache

Re: Some help with calculations please :)

You may appreciate a video that aired on PBS called Stephen Hawking's Universe. You may be able to find this video through your local library. I recall there is a segment where they follow a young physics student who enjoys collecting parts around a salvage yard and built himself a small cyclotron and other physics lab equipment, in his garage.

8. Jul 14, 2008

### Cups

Re: Some help with calculations please :)

Thanks guys :)

I actually just build the Van de Graaff generator.

I followed the directions as outlined here (http://www.angelfire.com/ak5/energy21/asimplevandegraf.htm), but I don't seem to be getting the charge from the rubber band. I repositioned the wire ends several times to make sure they were in the right spot relative to the band. Any suggestions?

9. Jul 14, 2008

### Cups

Re: Some help with calculations please :)

I tried to re-evaluate the device with a small clip of my cat's fur, and it does seem that with a 9v battery or a combination of the AAs and the 9v, the hair is attracted to the can. However, putting such high voltage into the DC motor wears it out quickly. It seems the way I have it set up, which is exactly to the build of the directions, I'm producing no where near 20,000v of static electricity.

It seems like the rubber band is turning the glass tube as opposed to rubbing against it, which would explain the very low production of static, but I don't know how to fix that since I built it exactly as it stated.

10. Jul 14, 2008

### waht

11. Jul 14, 2008

### marcusl

Re: Some help with calculations please :)

That is too marvelous! After designing, building and testing all the equipment, he can't afford a tank of hydrogen so he generates and dries his own, corroding away 6' of copper pipe and turning his hands green in the process!

http://www.niell.org/research.html" [Broken]
He looks to be about 9 years old!

Kudos to Fred and to his advisors.

EDIT: Cups, it's ok if the glass tube turns. Am not sure why you aren't getting higher voltage. Are your metal brushes close to the rubber band but not touching? Also, do you live in a dry or a humid climate? Humidity kills static electricity. If so, your machine might work better in the winter, especially if you're in a snowy region. (Or come to Colorado where the humidity never gets much above 20%!)

Last edited by a moderator: May 3, 2017
12. Jul 15, 2008

### Cups

Re: Some help with calculations please :)

Ah, you know what.. I just checked the humidity and it's about 60% right now, going up to a whopping 95% around 5am. I imagine it was the same way yesterday. Crud. How can I reduce the humidity in the test environment? I'm using an air conditioner =/

13. Jul 17, 2008

### marcusl

Re: Some help with calculations please :)

Crank that air conditioner to high and seal the room. If you can get the temperature in the room down to around 20F, all moisture in the air will freeze out )

Seriously, I don't know what else to suggest. Wait for a dry day?

14. Jul 17, 2008

### Cups

Re: Some help with calculations please :)

Hahaha, looks like I'm waiting for a dry day... which may be a couple months down the road =[ Usually it gets so dry during the winter that my nose bleeds on a daily basis.

15. Jul 18, 2008

### marcusl

Re: Some help with calculations please :)

Let us know how it works under dry conditions!