So I have a fusor made out of two salad bowls...
You might also want to see my old site about the fusor.
Nothing yet, anyway.
For the past year, I've been trying to deal with power failures left and right. Soon after the previous update, the power surged and killed my vacuum gauge.
The fusor has been out of commission since, and I've moved on to doing some other things such as scientific glassblowing and building a synchrotron.
What will happen to the fusor? The equipment is still all here. I may decide to fire it up once I get enough money for another vacuum gauge (or another control unit; it was the Baratron 112A that went up in smoke). I've been working on a high-voltage upgrade, too, but that huge transformer that I got seems to be a high-frequency one: at 240V/60Hz in, it draws up to 30A and only outputs 4kV.
I've accomplished what I set out to do, here: nuclear fusion in my garage. I wrote up some documentation about this project in the form of a book.
After the hot summer months, I've managed to get the fusor site back up. It was languishing with inattention because I was lethargic, and at the time it didn't seem like such an important thing. I had to get the house rewired first so I could get everything accomodated---having no adequate source of power really limits your options.
In any case, I'm lucky enough that it looks like the wiring will be completed this weekend, with a new 240V/20A socket for me to use the X-ray transformer with.
I'm also working on a side project that relates to the fusor---I'm learning scientific glassblowing. With any luck, I'll be able to blow a transparent demo fusor that can be easily packaged into a suitcase-carryable system. It'd be the ultimate demo for nuclear physics.
Let's hope I don't run into any other huge obstacles.
And as a side note, I've got a separate blog running at Neko Nyan Liberation. It won't be strictly limited to fusor stuff, but for the most part it looks like I'll be posting there too.
Well, I blew it. Quite literally. In the process of wiring together a saturable reactor for my X-ray transformer (which would like to take out my house's power unregulated; drew something upwards of 20 amps at a mere 20 volts), I accidentally shorted live out to ground while the Variac was set to "0".
It turns out that the fraction of a volt that the Variac put out was enough; since a Variac's a transformer, it gave me tons of amps through that short circuit.
In any case, the circuit breakers didn't flip off, but the socket died instead, nevertheless. I highly doubt any electrician would be willing to come in and actually wire a dedicated circuit up to this thing for me, if only because the entire setup looks pretty perilous.
In short: no more fusion unless I figure out my mains-side wiring better.
I've been up to a bunch of other stuff lately, mainly studying for AP exams and finals. I'm done with school around June 2nd, so after that it'll be fusion all the way.
I'm picking up a new X-ray transformer for a power supply tomorrow, which should deliver pretty potent power---50kV at maybe 30mA. A lot more than the cheesy dental transformer; it's about 250lbs and occupys about 2 cubic feet. Ridiculous amounts of iron in these things.
Moreover, it looks like I've managed to fix a vacuum leak by liberal application of nail polish. Before, the chamber would easily leak to 1000+ microns within one day. Now over one day, it leaks about 5. Much better.
So I'm number 22 on the fusor list, confirmed. That's pretty neat. Pictures of the setup and bubble counter as proof are here.
Unfortunately while doing my fusion runs I ran into some problems. My HV supply seems to have trouble with arcing, and the folks on the fusor board suggested that it might be an internal short somewhere. I've changed the transformer oil in the bucket, so now it's just to wait one week and see if that resolves the problem. Otherwise, I might be in for a long overhaul...
I just installed the deuterium feed last night, and the operation of the fusor's changed completely! Now instead of only the voltage to control, there's six different valves as well (D2 regulator, 2 shutoff valves, two leak valves, and a butterfly valve). I've managed to find a reasonable operating arrangement where I can operate at 23.8 microns or so and get 24kV, with little or no hands-on at that point. I'm pretty sure I'm wasting massive amounts of D2, though.
Look in the gallery for the image. Or up top, too.
The bubble counter isn't picking up anything, so I'm sort of wondering why...
Hey folks, just wanted to let you all know that the project isn't just dead, yet. I've been busy with other things, such as working technical theater for the school musical, but that ends on the 28th. Hopefully fusion by Monday.
Managed to get up to 24kV at the same old 7mA. The poissor looks the same as always, although I reckon the star-mode rays are getting thinner and more defined.
Click here (1.4MB, mp3) to listen to a small clip of how the Geiger counter goes off. (The 60Hz hum in the background is due to the 20 amp Variac right next to the microphone---bad placement, but there wasn't any other convenient spot.)
Also, I was mentioned in WIRED! Hurrah!
I managed to get up to 22kV (no April fool's joke). The Geiger counter's going crazy, definitely experiencing X-ray shinethrough here.
I'm pretty close to fusion now; I'm running at fusion-level energies. 19kV for the first time! At this level of operation the shell's already up to 120C, sounds like I could do some cooking...
Today I recieved the 2'x2'x1/8" lead sheet. I have it draped over the side of the fusor at the moment, but there's probably a better way to utilize it, as my hand on the variac and the tips of my feet will still be exposed to X-rays. (At least I won't be sterile...)
My pneumatic three-way valve also arrived, so I have a way to seal off the roughing pump instantly in case there's a power outage. The vacuum in the foreline manifold should hold the diff pump down to pressure while it cools off. It's nice and loud when it vents (100psi to atmosphere).
No pictures, maybe next week. My new analog meters should be coming in Wednesday.
After struggling for a long time with encoding, I managed to get this.
A higher-quality 80MB Matroska file is available through BitTorrent at http://fusion.wsyntax.com/videos/fusor_run_20070324.mkv.torrent.
I had another attempt at recording a fusor run, and this time it went very well. (The previous one ended up corrupted somehow.)
With the recorded run, I hit a record voltage of 16kV. I didn't go any farther because at around 18kV is where my transformer blew the 1st time; I don't want to go past 16kV without proper degassing under vacuum and sealing.
Moreover, I managed to get a one-frame snapshot of a "glitch". Exciting, since usually they're fast enough to be invisible. I'll study this and see what I can get out of it.
Video coming very soon, as soon as I manage to get x264, mencoder, and DV to play nicely together.
I recorded about 13 minutes of video of fusor operation with running commentary with the DV camcorder. It'll be on the net soon enough; I'm waiting for a new hard drive so I can import and transcode it down to a more managable filesize (~60mb).
Also, lead sheeting is on the way. 1/8" 2'x2' sheet, courtesy of McMaster-Carr.
A regular schedule for fusor operation will soon be up, to make catching something on the webcam a little easier.
So I managed to hit 15kV today at around 9 umHg. Not bad. X-rays are definitely streaming out; there are always white pixels flickering on the DV camcorder output. The star mode becomes more pronounced at higher voltages, with thinner, more vivid rays.
I managed to operate at 13kV for extended periods of time, controlling it so that the amps are as minimal as possible (barely lit discharge) while the volts are high. I'm using a DMM to measure voltage, and I don't really have an ammeter yet, so that's why I'm being so careful.
The star mode with the realigned grid is considerably better, and it looks really nice.
Hopefully I won't blow my transformer again as I proceed up into the higher voltages. X-ray shinethrough hasn't become an issue yet; it seems due to the design the viewport gets considerably less X-rays than on others' fusors. At 13kV I get about 2x the counts as ambient, which isn't too bad.
The fusor is back up and running after I managed to scavange a spare secondary from another one of the same model X-ray transformer. (I thought it was bad, so it went into my junk pile). I also have a nice new high-res image of the fusor while running.
At the moment both my volt and amp digital meters have been blown due to EMP/surges from the fusor. I'm switching over to an analog microammeter-based setup as soon as funds allow (they're pretty pricey, averaging about $60 a piece for a good D'Arsonval meter).
I also bought a new webcam, so hopefully you'll be able to see me operating the fusor while I'm at it. I'll post a daily fusor operation schedule soon enough.
If I'm lucky, this weekend I might also finish the code to interface with the serial port on my Baratron gauge, so that I can put up a live RRD/gnuplot based pressure graph.
Deuterium is also here.
I managed to burn through a secondary on my X-ray transformer at 13kV/12mA, well within the expected operational limits. I'm probably going to do lower-amp runs from now on if I do get the same model transformer. Such a pity... 7mA is a very low limit, and definitely cuts back on glow-cleaning power.
Edit: Well, ok, not within the operational limits. 7mA is the limit regardless of configuration. Looks like I'm off to search for a better supply.