Starting an accelerator project

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Jack Puntawong
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Real name: Kunakorn Puntawong
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Starting an accelerator project

Post by Jack Puntawong »

Hey guys,

I just want to keep you update on the progress of this linear accelerator project. I have scrounged most of the vacuum equipment I needed on the internet and will probably re-use most of the parts from my fusor. Also. Bill have donated the accelerator tube that's needed for this project. However, I still need to build a Van de Graaff generator and the deuterium gun. Also, I still need to find a vacuum gauge that can measure between 10e-4 to 10e-7 torr. Here's the design and the parts I have so far:

Image

The design have been modified a bit but I haven't had a chance to re-draw it on computer.

Image

The accelerator tube

Image
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Dennis P Brown
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Re: Starting an accelerator project

Post by Dennis P Brown »

You asked to see how I "packed" my accelerator globe - here is a drawing and some photo's. This has been for me, a very difficult past year and all non-essential projects have been postpone indefinitely. Note: I added a support for the battery but have no image of it. The support has a hollow hole for the accelerator tube and a flate base area that the battery "housing" is affixed to. Any design will work but I will try and get a photo of that critical piece this coming weekend if time permits ... .

Found the orginal photo. So, the first photo shows the globe with the battery. Also, I have moved the high voltage multiplier into an oil filled flexible tube to better contain it from arc over. See the first pdf for a labeled picture of the contents of the Accelerator globe. Note that the "white flex tube" just under the battery holds the high voltage multiplier. The older pic at the bottom shows the units uncovered. The second PDF shows the rough design. The ion gun (alone) is in the second photo (see pdf for details). The complete globe (less battery) is in the bottom photo

Very cheap ion gauges are available that handle the high vac range.
Attachments
Accelerator (4).pdf
(202.57 KiB) Downloaded 469 times
AcceleratorGlobeImageMVC-034L.JPG
Simple Ion gun with a Penning Trap Modification.pdf
(10.35 KiB) Downloaded 381 times
D2Gun.JPG
PenningIonGuninGlobe.JPG
Last edited by Dennis P Brown on Mon Apr 06, 2015 3:29 pm, edited 7 times in total.
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Richard Hull
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Re: Starting an accelerator project

Post by Richard Hull »

Nice work Jack! keep up the effort. We look forward to future reports on your effort.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Jack Puntawong
Posts: 150
Joined: Tue Aug 28, 2012 9:10 pm
Real name: Kunakorn Puntawong
Location: Bangkok, Thailand
Contact:

Re: Starting an accelerator project

Post by Jack Puntawong »

Thank you Dennis for the pictures and Richard for the support.

Dennis, I have just noticed that there are two tubes coming out of the faraday cage. I presume that the left translucent one is for the deuterium but can you explain what the other tube is for? Also, I have read through your linear accelerator threads and it seems that your Van Der Graaff generator is not producing enough current. This is also going to be a major problem for me because VDG current is determined by the size of the belt and the sphere and finding large stainless steel sphere is extremely difficult and expensive. If any one know where to find or acquire such large sphere, please leave some comment below.

On the brighter side, Bill and I found a beautiful flange and a glass tube for one of the sides of the accelerator tube. The gas goes through small hole in the bottom of the flange and up into the glass chamber. Then it'll be ionize by high voltage potential from the feedthrough and focused by the electromagnetic coil. ( I think I'll replace the electromagnet with a donut neodymium though).

Jack Puntawong

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Dennis P Brown
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Re: Starting an accelerator project

Post by Dennis P Brown »

First, large steel sphere's are sold for use as garden displays (I got one.) Being steel, it is a good idea to grind cut the holes into them. Cutting using standard tools is very difficult (this steel is VERY hard) and not for someone inexperienced like me! After cutting my sphere into two halves I decided to set it aside and buy a commercial VDG globe based on aluminum - cutting/drilling such steel is slow and frankly, too much work (I realized that mounting the two cut halves together was a difficult job and I had enough issues to deal with so I realized I was wasting time on problems that didn't need to be solved by me.)
So my current sphere was bought from a VDG company (some will sell you a sphere if you ask them.) But if you want a very large one, try the garden sphere companies on line (these sphere's are called "Gazing Globes" and are used to beguile evil spirits ... that use didn't work for me (lol.) Rome Industries is one company that sells these.)

My accelerator sphere has one large hole for the end of my accelerator tube (the end of the ceramic tube that has the deuterium source/gun in it) and the sphere also has two small holes: one is for the deuterium feed line entry and the other is for a long plastic rod that was needed to control access for the variable resistor that is used to adjust battery voltage that, in turn, controls the high voltage deuterium ionizing power supply.)

My accelerator tube has a ceramic plug glued with epoxy on one end (this has the copper capillary tube for the gas supply), and for the other end, a simple "O-ring" compression fitting 25 mm KF flange (this unit came with an ionization gauge tube I bought on line ridiculously cheap!) that connects the accelerator to my turbo and target area.

As Richard points out and I found out the hard way (articles don't mention this issue) voltage/current leakage for a LA/VDG assembly at the globe(s) can be terrible and drain away all the high voltage resulting in far too little current.

Best of luck and if the VDG gives you any trouble, a few people here are really knowledgeable on dealing with those issues!
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