1. ### Atomic Parts

9
The attached photo and youtube link is my current progress regarding the engineering and building of the 1971 Scientific American plans of a particle accelerator. My design will differ in several ways specific to vacuum tube, drift tube and equipotential ring design. However, the basic concept of a VDG driven cascade tube is still the primary design.

Already, since the photographs and video were made, I have changed the design in several ways. Once all the engineering gremlins have been worked out, I will use the pictured model as a template for a final "working" version.

Mark

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Last edited by a moderator: Sep 25, 2014
2. ### Bob S

Looks like you are serious about building a machine, and have done a lot of reading on the subject. Do you plan to accelerate electrons or ions(protons)? What is the vacuum you think you need? What is your DC terminal voltage? What is the spacing of your drift tubes, and how did you determine it? Do you plan to apply ac voltage to your drift tubes? What do you consider to be successful completion of the project?

3. ### MattRSK

20
Hi,

Looks like an interesting project. Are the books displayed at the end of your project worth a read for a beginner. Could you suggest a book that would explain what happens with a particle accelerator?

4. ### Atomic Parts

9
Hi Bob,
1) I plan on accelerating protons.

2) Vacuum will be in the realm of 10e-7 torr. Shouldnt be a problem with the diff pump and some conflats.

3)The VDG will be a 750kv model with a 22" dome.

4) The drift tube spacing is 3/4". This was the original specs in the 1971 article. Being a proven design, I decided not to tamper with it. However, my alterations of the 1971 design includes a modular and easy to disassemble system. That alteration is not pictured in the above jpg and youtube video. The drift tubes will be connected with 1" dia 3" long pyrex (heavy walled) tubing. (I call them spacer units). The drift tube assembly will slide in to the containment tube which is 2" in diameter. Later, if I decide to alter the drift tube spacing, all I will have to do is make longer or shorter spacer units. But, I am fairly confident the 3/4" spacing will be adequate. Any adjustments in that arena can probably be done by voltage and equipotential ring tuning.

5)No. AC voltage to the drift tubes would convert this into a (HF) LINAC; providing each tube is sequentially bigger. My project is purely a DC assembly. Just like the early VDG and Cockroft Walton accelerators of the 1930s.

6) Neutron production.

I should add that this is a VERY long term project. I am predicting completion of the tube in August. Then there is the ion gun design, the VDG unit, vacuum system, gas handling system, pre-ionizer, etc, etc, etc.... Family and day-job responsibilties will always come first with the usual expected delays in hobby projects.

Last edited: May 22, 2009
5. ### Atomic Parts

9
Regarding the books. All are good for beginners except Bruno Rossi's High-Energy Particles. That one is fairly complex theory with alot of math.

However, the best one I know of for beginners is ACCELERATORS: MACHINES OF NUCLEAR PHYSICS By Robert R. Wilson. This publication is widely available at a very cheap price (usually $2 to$5).

http://www.amazon.com/ACCELERATORS-...=sr_1_3?ie=UTF8&s=books&qid=1243049361&sr=8-3

6. ### Atomic Parts

9
Attached is a youtube update (part 2) on the Accelerator tube. At this time I am working on the ION Gun. That will be my next youtube installment (part 3).

Mark

Last edited by a moderator: Sep 25, 2014
7. ### ZapperZ

30,735
Staff Emeritus
You seem to have done everything except the safety consideration. Have you ever considered the amount of radiation you get out of this, both prompt and residual? Proton impact on almost any material at that energy can induce residual radiation that can linger for quite a while.

Is this done in a proper lab with a controlled shielding, etc.? Do you know if you will be in violation of safety laws?

Zz.

8. ### Atomic Parts

9
"You seem to have done everything except the safety consideration."

Ha! I wish you were right. Actually this is just the very early stages of the beginning. I am not even close to the middle yet. Just a quick list of things to do include (but not limited to):

1) Ion Gun design
2) Ion Gun prototype and testing
3) Ion Gun build
4) Target design
5) Target build
6) Vacuum system design
7) Diffusion pump to target chamber connection assembly.
8) Gas handling system / valving (this one is very tricky due to leaks)
9) Power supply system for the Ion Gun (must be small enough to fit in the VDG dome)
a) Pre Ionizer
b) Filament power (battery)
c) Nylon line control system
10) The VDG itself
11) The VDG Sphere
a) Must be designed to be as seamless as possible (flangeless IKEA Blanda Blanks)
b) Pressed out hole for the tube. Must be rounded. Special dies must be made to
acheive this.
12) Overall wiring system.
13) Remote control system
14) Video monitoring system

So, as you can see I may be a full year away from any preliminary function test of this project.

Regarding safety, the system is located in a detached building and is designed to be operated via remote control and monitored via video.

"Do you know if you will be in violation of safety laws?"

No more than if I was operating a Fusor. Same stuff. Go here and search the forum on laws and regulations regarding items such as this.

http://www.fusor.net/board/index.php?site=fusor&bn=

Mark

Last edited: Aug 7, 2009
9. ### ZapperZ

30,735
Staff Emeritus
Er.. I work at a particle accelerator, and am quite familiar with the OFFICIAL (not the public forum version) safety regulations, and in many cases, there are site specific, both local govt. and state govt. regulations that could be in addition to the federal regulations.

If you are not that concerned about it, then there's no reason why I should.

Zz.

10. ### Atomic Parts

9
I guess you are right.

All done

11. ### Atomic Parts

9
In the interest of clarity, I feel it is necessary to explain my last post.

ZapperZ is absolutely correct. A project like this poses multiple hazards and should not be attempted.

After careful consideration, I have decided to discontinue this endeavor.

12. ### Blenton

190
I could imagine the feds zipping to wherever this is if it ever produces anything radioactive. Shame you're discontinuing it.

13. ### Atomic Parts

9
Hi Blenton,
ZapperZ is the expert. Why risk anything dangerous or possibly unlawful? The project is discontinued, disassembled and I am returning to my interest in silicon based plasma.

The accelerator related youtube videos have also been removed in the interest of public safety. I would also recommend that this thread be removed from this forum, but I doubt that is going to happen.

14. ### ideasrule

2,315
Sadly, the most interesting projects involve taking risks. I find it hard to believe that you're discontinuing the project. If that's what you're really doing, why haven't you considered researching the relevant laws and safety procedures? Why not seek out experimentalists and ask for advice?

18,480
Staff Emeritus
That site seems to have the legal philosophy of "how to hide what you are doing so that the law enforcement agencies never find it". That's an odd attitude for something legal.

Licensure is not trivial. One of the very first questions they will ask is "you're producing neutrons, so you'll be activating things. How do you propose to characterize and dispose of the radioactive waste you produce?" To give you an idea of what this entails, the instructions for sending low-level waste to Barnwell are 69 pages long.

16. ### Atomic Parts

9

"That site seems to have the legal philosophy of "how to hide what you are doing so that the law enforcement agencies never find it". That's an odd attitude for something legal."

Plain and simple, that is a false statement. If you spend even a minute browsing that site you will see that it is no secret that the average member is striving for neutron output. They even have a list called "The Neutron Club". Every so often, a member will activate some type of metal. When this happens, the achievment is plastered everywhere on the site.

After reviewing your "recognitions" I find it suprising that this is your definition of "how to hide what you are doing so that the law enforcement agencies never find it."

18,480
Staff Emeritus
I disagree - do a search on "legal" on that site and you'll see many a message on how to hide what is going on. The thread "Hobbiest Trouble" was particularly enlightening.

### Staff: Mentor

I won't remove it, but I will go ahead and lock it.