I'm building a Farnsworth-Hirsch fusor. Essentially, this is an ion accelerator that accelerates gas particles towards a central plasma--if those gas particles are deuterium, then you can get fusion when they collide.
A fusor like this involves high vacuum and high voltage, both of which are easily obtainable by the amateur experimenter. The voltages I'm dealing with most likely exist around you already--20,000 V at 20 milliamps is found in typical CRT monitors, as well as in arc lamps. As for high vacuum, a CRT contains that too, but it's nothing--not even close--to household cleaning vacuums. Perhaps the closest everyday example of it would be a plasma globe or light bulb.
Links, and other things:
Here are a couple of handouts and other things I've written up to describe my project:
- A small pamphlet I assembled for an in-class lecture.
- A very small summary of what I'm trying to do; assembled for potential investors.
New site elsewhere!
Please note that this site is outdated. Any newer fusor information will be presented at http://fusion.wsyntax.com. Thanks!
(Place your mouse over the picture to see a description; clicking on the thumbnails leads to a full-resolution picture.)
An updated fusor DXF
A paper fusor mockup
Actual, better fusor plan (preliminary)
A plan nailed to the ground.
I've been rolling around in languid boredom for the past couple weeks, taking full advantage of this summer for its lack of responsibilities. In the meanwhile I've updated the fusor budget and assembled a quick handout for laypeople about this project.
I've found that it's hard to actually give hard numbers to people in terms of expenses, since all of it is surplus/scavenged parts, which can vary in price and availability drastically even from one day to the next. I put down worst-case estimates.
That 700lb pallet of diffusion pumps I bought turned out to be quite the bad investment, since not a whole lot of people have the capability to transport that sort of stuff cheaply---next time I'll remember to take that into consideration before getting all giddy about the low pricetag (and perhaps that's why it was so low in the first place).
Currently in progress about writing a blog dealing with laypeople and their apprehensions about the unknown (ie "fusion is deadly, scary, and out of reach of a high-schooler").
Getting a sense of scale and bearing...
I've been refining the design of the fusor and have decided to go with several (4) 2.75" Conflat ports, one KF25 for vacuum, and one Swagelok 1/8" tube fitting for a gas inlet. Managed to get it all down on the DXF too (that file is now up-to-date). It's actually suprising, now that I can get a sense of how big (or how small) this fusor will be... I'd imagined that it'd be a little more grandiose.
I also managed to undo that nasty little screw that was holding the rest of the pump together. I found some very, very stripped threads.
Remember that place to get a good diffusion pump? Here's my purchase. I will probably be reselling some stuff since I don't need all of it---I only need one of the smaller ones in the boxes. (Heavens, who knows what I'll do with the giant behemoth of a pump on the right...) Freight shipping will be, for sure, more than what I paid for it. ^^;
Fusor plan GET!
I've also spotted a good spot for finding a diffusion pump, so hopefully that'll turn out well. (A surplus store/auction in an undisclosed location--I can't go around telling people, or else the price will go up. :)
A fusor plan, a nasty nut, and priorities
Ok, I have a plan for the fusor. I'm going to clean up this sketch, and remove a couple superfluous ports (this is a picture of a dream fusor, and I only need about half of those ports to be what they are). I'll submit it to a couple companies in the area that do vacuum chamber fabrication and try to get a quote---hopefully it'll be reasonable and I'll actually be able to afford it.
There's one bolt on the pump that's having significant troubles with actually getting undone. I'm applying large amounts of torque with a screwdriver and a wrench---managed to break one set, so now I'm down to drilling holes in handles and sticking in long poles. I know there's a rachet around here in the back somewhere, but I just can't find the damn thing. Most likely a new one will end up getting bought.
Right now, this fusion project is probably the most important thing for me---I'm on a roll, passion's in my heart, and I can get this done before September if I continue on at this rate. This being said simply because it's dislocated all of my other interests, such as anime and origami and PCs. It's not every day that you get to build an IEC fusor when you're 15.
I will be spending as little as possible at Anime Expo in order to give myself a bigger budget for this project.
Funky pump handling and Vacuum Taboos.
I washed the vacuum pump's parts with water, and then soaked them with water to loosen the grime. I'm pretty sure I've broken the most high vacuum taboo, and vacuum purists will cry when they see my setup.
I have however found an electric oven to bake my parts in, which should help outgas considerably.
Luckily the parts are made out of stainless steel (or steel), so the rust that seemed to form just wiped off with a paper towel. Phew, it was about one inch close from utter disaster.
There's one screw that I have to undo to finally get the pump -totally- disassmbeled, but it's not budging. I better get it done, quick, because there's no way I can install the vanes without it out of the picture.
Fusor work in progress...
Funny how I always forget to update this site, despite the fact that I've been able to get some work in lately.
I've gotten around to acquiring some parts, including a vacuum 2 3/4" Conflat viewport. It's quite pretty, and I managed to snag it off eBay for $75 all included; I save $25. Not a terrible lot, but enough to make a difference.
The other acquisition as of late is a vacuum pump of my own, which I found to be in terrible condition. I saw an ad on Craigslist the other day for a Savant VLP200--equivalent to an Edwards RV8; it's a very beefy pump design. The offer was for $160, and the MSRP for a new one is around $2800 (Quite a steal). Picked it up, and needless to say, I'm wondering whether the purchase was worth it. This pump has so much dirt and grime and ridiculous wear on it that I can't possibly imagine how anybody would have bought such a pump and mistreated it this badly. Two vanes, the entire basis of the pump's operation were broken; they seem to be made out of ceramic or somesuch. They're also lacking springs to hold them against the walls of the chamber, resulting in little or no compression.
I received the pump dry, sans oil, meaning that the first step would be to fill it with oil (or in this case, flushing fluid). Used a fine amount (around 20 oz), and then proceeded to run it for a while. It ran to some capacity (my hand would stick when left over the outlet), but it eventually seized. It never started up again, so I decided to open it up and see if I could dislodge whatever the problem was. Most likely, sometime during this session of disassembly, the vanes got broken and chewed into little pieces---how the hell it could have happened, I haven't a clue.
In any case, the pump's repair costs are hefty, weighing in at around $200 for a pump rebuild kit and $30 more for various fluids (oil and more flushing is in order). I'll probably end up spending around $400 on this pump, labor and time not included. At this point, I'm crying over the purchase---would you believe that I'd found a nice Balzers/Pfeiffer leak detector back in Anaheim (about an hour drive) for $300 on eBay? That thing would have pumped much better, and had quite a bit more value ($20,000).
Ah, well. Caveat emptor, they always say.
The viewport arrived in great condition, and there's not much to say about it other than the fact that stainless steel is still suprisingly heavy to me. Holding it in my hand, it really feels worth the $75. Heaven knows what the fusor assembly will feel like. :) (I also figured out how to take decent pictures, for once...)
From here, I just have to peg a company to fabricate a vacuum chamber for me--a 6" sphere with 8" conflat gaskets and a couple other ports. Looking for a price around $500, since that's close to what others have paid for their chambers. I'm also in the process of building a capacitor-powered resistive spot welder to weld the grids together; I plan to use copper pipe and caps for the terminals. If I up the capacitance, it should have no problem welding the thin .025" stainless steel. It'll also give me incentive to buy those beefy capacitors, a sure sign of mad genius when seen in someone's garage. :D
I haven't really been able to spend the past couple of weeks on this project; time's a-slippin'. I was called on by my Dad to do some priority server tweaking/testing/beating, and I've been working on that assignment pretty much 24/7 since last Monday.
People still get fusion and fission confused when I talk to them about it. Oh well.
Long time no see!
Well, finals have come and they're in the process of going (only a couple days left); this explains my absence from any fusor-related work as of late.
Since my original proposal to build a fusor had been shot down, I did end up presenting a 20-minute lecture instead to my classmates. It seems like it went really well; people were listening and tended not to be bored. They all have basic atomic knowledge, so it was pretty easy to explain the ion-acceleration crux that the fusor is based around.
I handed them this pamphlet; it goes over pretty much everything listed in the outline a couple posts below. It's written in a highly informal style, made for the masses. And yes, there may be glaring technical errors in the subtlety of things, but they needed to be simplified in order for my classmates to understand (For who could -really- explain the basics of vacuum technology, high voltage supply, and ionization in the span of 20 short minutes?). The general premise is there, and if I've made any errors at all on that level, please comment or send an email my way.
I've also been lucky enough to receive a hardcopy of Kurt J. Lesker Inc.'s catalog, and it's very pretty to look at. Prices are forbiddingly expensive, though--there aren't any real discount deals like there are with Dunway. (I'm looking especially at T/C gauges, the cheapest real vacuum instrumentation there is. At Duniway, they have a $200 tube/controller/meter combo!)
It doesn't look like building a real, solid metal fusor will pose such a problem. The steel hemispheres are cheap, adequate Conflat flanges can be found for reasonable prices, and I've found a nice source of passthroughs at Ceramtec (a 20kV weld passthrough for only $35! What a steal!). The high voltage looks a little formidable, and the gas handling as well, but those have parts that are a little more commonplace than vacuum.
Safety is still the most paramount issue here; I don't think my parents trust me with high voltages still (and they might be quite right in that judgement.)
I've set a deadline for myself that I'll have first light by at least the beginning of September, in time for the new school year. My summer's opened up considerably and I don't think it'll pose an issue to work at that sort of pace.
Also, in other news, I've had to return the pump and the vacuum system back to Poly. No worries, I'm sure they'll let me borrow it (I hope) if I actually manage to get everything up and fabricated here. Otherwise, it's just $200-500 more to find a new pump from surplus somewhere. Maybe if I'm lucky I can get a turbo pump in the deal, too....
Looking for an advisor...
Alright, so I've come to terms with the fact that this project isn't safe (well, at least not intrinsically); there's certainly radiation hazards, high voltage hazards, breaking glass hazards, implosion hazards, flammable gas hazards, etc...
So, being that I haven't dealt with any of the above in practice (theory simply isn't good enough for most things), I've begun looking for someone who'd be able to help me; my parents and teachers will also sleep better at night knowing that I'm at a much reduced risk of killing myself inadvertently.
My presentation date has been moved up to next Friday (as opposed to the Friday afterwards, which was what I was originally aiming at); so be it. I might make a paper mockup of the grid inside the bell jar just for kicks; it'll work for demonstration.
I am beginning to feel a little silly thinking that I could've done this in one go; while I'm about $800 away from a fusor, the likelyhood of death is relatively high. So much for that. It's always the things that money can't buy that really matter, namely life and knowledge.
Status as of 03.05.2006
Days remaining: 16.
In terms of the actual project I was assigned, I don't think I'm going to have a lot of problems; I have a 20 minute speech to give which is far insufficient to present all of the knowledge I've accumulated.
As a general overview, here's a rough outline:
- What is fusion?
- How can it be attained?
- Magnetic Confinement (Tokamak/Stellerator)
- Inertial Confinement (NIF)
- Miscellaneous (Muon-catalyzed/Palladium/Sonoluminesence)
- Inertial electrostatic confinement (Farnsworth Fusor)
- Basic principles of a Fusor
- Present demonstration model (and run, if possible)
- An overview of practical implementation
That should last me. I'm going to appeal for permission to run the demo fusor, if I can get it cobbled together; there isn't any reason why I shouldn't be able to get star-mode, or at least a poissor, if I take appropriate precautions and make sure everything's safe. At 20mA/7-10kV, there's not a whole lot of risk of X-rays; the glass bell jar will be appropriate shielding if any are created. (There isn't nearly enough current to be dangerous.)
Albeit, if I'm going to make a demo fusor, I need to get moving; parts take about a week to ship, leaving me with a week to fabricate all the local assemblies--oh boy, that's going to get exciting, to say the least.
I forgot to mention, I picked up a nice 3000 psig regulator back on Friday; pictures soon. Looks like it has a CGA 346/326 connector, but I can't tell the difference without diameter numbers. Output is 1/4" NPT male.
If I'm going for actual fusion, I reckon I'll be spending about $2000 over the next couple of years.
Turning into more of a long-term project.
Days remaining: 17.
Pending safety approval from my parents, I've still got the parts list on my hands and it's entirely possible that I can work in a demo fusor in the limited amount of time I've got (a little over two weeks). Barring that, I can still write a kick-ass paper on the topic.
About writing papers---writing a paper after experience and trying to build something is a lot more thorough and complicated, compared to the majority of my classmates who are still doing relatively simple, Newtonian-ruled machines or experiments; the entire lot of them are probably doing something that's been done before.
(But my teacher says he's seen mini railguns as projects, so go figure.)
In any case, if you've got any advice to offer, or have any warnings for me to heed ("You're going to blow up the world, damnit!"), I'd like to hear them. Email me anything--flames, comments, questions--at email@example.com
On the chamber design, I'm considering getting that custom baseplate made with NW25 fittings, since they offer expansion--I have to remind myself often that this is a long term project, and this is only a beginning.
Oh, and I got a quote from Advanced Specialty Gases over in Reno, Nevada--$184 for a 50L lecture bottle of deuterium, including shipping. Whether or not this is a ripoff, I've yet to decide--I've heard of prices as low a $60, but perhaps with local pickup.
Also, about the leaky bell-jar--I've managed to get it to keep some sort of vacuum for at least 5 hours by applying vacuum oil to all seals and contacts that the jar is touching. (Aiyah, I really need a gauge...) While it's not vacuum grease, it sorta does the job.
Still going strong...
Days remaining: 22.
Anyway, I was able to talk a little bit to my parents and to the faculty--I'll be able to bring in a video of the fusor if I get it to work, but most likely I will bring in the whole apparatus but leave the high voltage supply behind. It'll still look cool, have some clout (perhaps even more, considering that something on this scale hasn't happened before at Poly), and get me a good grade.
I'm glad, though--my parents are all behind me on this project; they really want to see it completed, if only for the reason that star-mode discharge looks ridiculously awesome.
I'd imagine that it's the most interesting light fixture ever.
In other matters, the bell jar system has a definite leak--it can't keep a vacuum worth anything. If I leave it for more than an hour, the chamber's down to atmospheric pressure by the time I get back; there's a pitiful leak somewhere, but I can't hear any hissing sounds. I suspect that it may be the actual gasket that the bell jar is sealing to the stainless steel plate on; it's a very suspicious, flimsy, cheap feeling, non-elastic rubber disc that's supposed to allow the jar to seal "without vacuum grease." This is true, I suppose, for low definitions of "seal."
The pump's running well, now that I have all the proper equipment to seal it off and give it a run for its money. I haven't got a gauge yet, so still no idea on its quantitative performance.
At the very least, the pump is running underneath 14 Torr, since water will vaporize.
Project outside of project guidelines
Days remaining: 23.
My project has had its support offically rescinded due to the various safety issues. This is the message:
It is with regret that I announce that Raymond's proposed Nuclear Fusor, to be built for for his Conceptual Physics independent project, is no longer considered acceptable for that assignment. For those of you not familiar with the history of this project, Raymond submitted the original proposal several weeks ago, and asked for assistance in building the fusor using plans and information gleaned from the Internet. None of the Polytechnic science teachers had any experience with this kind of thing, so Raymond was referred to Dr. Charles Barnes at CalTech, a physics professor emeritus who was more than happy to act as advisor/mentor on the project. Indeed, Raymond informs me that Dr. Barnes has conducted one of these devices himself. By all accounts, though, there are risks associated with building these devices, some risk associated with the wavelengths/frequencies of the radiation produced, and certainly some risk in working with the high voltages that are required to operate a fusor. While these factors are by no means unknowns, they are risks, and certainly of a higher-level than those associated with most high school science projects. To add to the difficulty, there is really no one that is able to supervise Raymond during the construction of the project. It is highly improbable, but possible, that Raymond could be injured--by high voltage, by radiation exposure, or simply in the act of constructing the fusor mechanism itself. As interested as I am in encouraging Raymond's interests in physics, I also understand that the school is not able to assume responsibility for any mishaps that might occur during construction. After learning a bit more about the details associated with the fusor, therefore, and after consulting with others at the school, I've decided to rescind approval of this project. Although Raymond is still more than welcome to conduct his presentation as a research project on theoretical nuclear fusion--and indeed, already has more than enough information collected for that presentation--he is not authorized by Poly to construct or operate a nuclear fusor as part of his project. If he chooses to continue to pursue building a nuclear fusor, it will be a personal project, and nothing for which the school will have any responsibility or liability. I've already spoken with Raymond about his personally, but I wanted to formally let everyone else know about the status of his project. Sincerely, Richard White
My take on the matter: OK. I will build this on my own time, get my own advisors--I will succeed at this, no matter what: no matter what the timeframe is, it'll get built.
Since I still live with my parents, they've laid down some stipulations if I'm to continue on with this outside of this assignment:
I need to have a third party verify the safety of my activities.
Active supervision during all working hours is strongly recommended, but not mandatory.
There needs to be some assurance on my side that I won't do anything that might endanger anyone.
In terms of the first stipulation, I need to find a third party who my parents can talk to and ensure that the risks are managable; they also need the risks enumerated and explained to them. (While I can do this, they want verification of my knowledge.)
In terms of the second stipulation, it's to ensure I don't kill myself by making a stupid wiring error.
The last one is just to cover their bases.
Also, the various fittings I needed came in--I now have a vacuum pump and bell jar combo that I can use for other, interesting experiments, including the infamous "water boiling and freezing simultaneously" one. (I'm doing it, despite the fact that I know it's very, very hard on the oil--I'll do it this once and then flush the oil.) Poly can appreciate this, at least. :) (Pictures in a bit.)
Safety issues and regulations
Days remaining: 24.
There are some various safety issues relating to this project that need to be taken care of first, before I can make anymore progress:
I need a mentor, a guide. While I can do this by myself, my competence is not so much that I can insist on it. I have little to no experience in the fields of vacuum technology, high voltage, or gas regulation. It may or may not work if I build it without verification.
I should be working under supervision due to the fact that I'm a minor, have no prior experience, and that I'm working sans decent amounts of sleep. Everything should be double checked--especially the deuterium manifold or high voltage--to make sure it's safe.
The radiation created by this machine needs to be taken care of and accounted for. While it's low dosage (X-rays and possibly neutron flux), and not of any significant biological consequence, there is still a potential for exposure. Considering that I will be presenting this in front of the class, if the school, parents, or other people get wind of this, there could be a bad result.
Considering all the above, the school might be held responsible if anything happens to me--while I'm not officially under the auspices of the school (it's considered that I'm going above and beyond the typical project, and I hope they recognize that), if something bad happens it'll still have a backlash headed their way. Certainly cries of "Why didn't you prevent him from building that?!" are not something that Poly wants to have mentioned over and over again.
All things being considered, however, this machine is perfectly safe if assembled correctly; I already have anecdotal and scientific evidence from people who've done it, researchers who've done the math behind the concept, etc. There is no reason for anything to go wrong, unless I mess up or something unseen occurs. And while the chances of it are small, there needs to be a safety net.
Budget is currently coming up fast on $750. Vacuum parts have been priced out, costing around $600; assuming $50 for machining the bell jar baseplate, that leaves $100 for acquiring an old used neon sign transformer and the appropriate rectifier diodes, along with adequate instrumentation. I cannot cut corners here, under penalty of death (or at least large amounts of pain).
I need to get around to looking for machinists that can TIG weld and machine out of 304 stainless steel a nice 8" dia. 1/4" thick plate. I'm drawing up specs right now, so that should help. This'll be the bell jar base; it needs to be custom since I'm adding the high voltage passthrough in the center; most baseplates sell with a vacuum port there.
I also learned today that the sale of deuterium gas is regulated by the government, or so Spectra Gases says; last I checked it wasn't. However, they're probably taking into consideration the fact that I'm a minor--selling compressed flammable gases to a young kid may be what they're trying to stem, and what the government has issues with. Either way, once the above safety issues are worked out, there shouldn't be any problem acquiring the gas through Poly.
Where the heck are the parts I ordered last week? Both the Welch adaptor and the HyVac ISO fitting stuff have yet to arrive.
Days remaining: 25.
The oil shipment came in from Duniway today. I've been shopping around and trying to arraign a budget for the entire project--a lot of it depends on surplus, so it'll depend on what I find. Also, as I've mentioned before, vacuum stuff is ridiculously expensive.
Days remaining: 26.
A wasted day. Spent most of it on other homework-related things and working the musical.
Parts budget, and orders...
Days remaining: 27.
Parts are expensive for most anything vacuum related--high purity gas valves, regulators, metering valves--the entire lot of them for my project might cost $200+ if I don't find a good source for them. The high voltage aspect of the system is perhaps the easiest, since neon sign transformers will work rather peachily--especially if the voltage is increased a tad by a Variac on the line. I also don't think I'll have any problems building the grids or fabricating the bell-jar base; those two use pretty common techniques.
Vacuum component prices need to suck less.
At this rate, it seems that my budget will be running over the original $500 spec--but I'm going to try as hard as possible to keep it under $1000, since I simply don't have that sort of money.
Luckily, there's also a replacement for a neutron counter in case I can't get a hold of one--a cloud chamber. The fusion process emits protons in addition to neutrons (50% chance of each), which should be pretty easy to detect. Cloud chambers are also ridiculously easy to build compared to everything else here.
As a side note: running as technical crew on the school musical is extremely time-consuming, but fun. Luckily, there aren't any more weekday rehearsals (except for the Friday show), so I should be able to get decent amounts of work in.
Additional info under my belt.
Days remaining: 28.
I've just gotten back from a meeting with a professor over at Caltech, and he brought several things to my attention:
- The electrons also react in the fusor--they go the opposite way. Where do they go? (X-ray production)
- A suprisingly large amount of low-Z fusion math is kinematics about mass and energy.
- The Hirsch-Meeks fusor concept is totally legitimate--there is definitely a reaction happening, no hoax involved. Whatever it is the guys over at the Open Fusor Consortium are doing, it's real.
- There are some other considerations that need to be taken into account for deuterium-deuterium fusion, including electron screening (not likely to happen in my apparatus) and recoil energy usage.
I'm having a grand ball here; it's a lot of fun.
More accesories ordered.
Days remaining: 29.
I ordered a nice 'ol gallon of pump oil and flushing fluid from Duniway Stockroom, along with the rest of the associated vacuum fittings (ISO NW centering ring & clamp) from HyVac. Oil should be here on Monday, and the other stuff should arrive Tuesday or Wednesday.
Some accessories ordered
Days remaining: 30.
Ok, I just ordered a couple of fittings for the vacuum pump online--an ISO NW 16 inlet adapter and a blank-off. They're ridiculously expensive; $55 for the two of them without tax or shipping. Why is it that all vacuum equipment is that way? I mean, even the blank itself--which is just a machined single piece of 304 stainless steel with no seals--cost $18. It seems that all vacuum equipment is priced this way. (This all from Welch Vacuum Products directly.)
Or, at least when buying from those who know what they're dealing with. I'm considering searching eBay for parts, despite the turnaround time.
Pump behavior normal, more tape review
Days remaining: 31.
The pump's gone back to its normal behavior, with the oil level settling to a little higher than half when cold. The differing factor here was probably the capped off inlet--I'd run it and hadn't remembered to uncap it when leaving it cold, which means that the vacuum was probably affecting the oil level a little bit. It now starts up normally.
I've begun watching the second of the fusor-related HEAS tapes; it's the one about actually doing fusion and the construction of Richard Hull's Mark III fusor. It's really exciting, as he shows the process behind an entire run, from start to finish, and then extrapolates reaction rates from the reading's he's got. Very neat stuff.
I'm meeting with Dr. Barnes over at Caltech on Friday. Meeting was put off due to conflicts.
Woohoo! Tapes arrived!
Days remaining: 32.
Anyway, today the three tapes from Richard Hull and they look pretty appealing--did a quick overview of the first introductory fusor tape and the video is simply tantalizing. Despite its low resolution, star mode on a VHS tape still amazes the heck out of me.
The documentary style is a flashback to the 80s. :)
I should be able to get some more time to review the tapes; there's about 6 hours of footage to look through. The issue's complicated by the fact that there's only one VCR/TV combo in the entire house--while I have a VCR here, the TV's out in storage for space considerations. Perhaps I'll haul it out again.
Status as of 2006.04.16, 20:52
Days remaining: 33 (presentation date 2006.05.19)
The most progress out of the other categories so far. As of now, I have a pretty well operating vacuum pump, and I know where to get my fittings and possibly the bell jar. I need to look for a spare bell jar plate so that I can drill holes for the highvoltage passthroughs and deuterium gas line. Also needed is a gauge of some sorts, preferrably thermocouple, so that I can measure the (lack of) atmosphere in the device. At current, I don't know how many sources of equipment I have--if I can manage to scrounge things from departments over at Caltech, I'll be glad, but I don't want to overestimate generosity and end up with nothing at all.
So far, the only thing I've gotten done here is research. I've been looking at the neon-sign transformer method of creating a high-voltage DC source, but I'd really like it if I could have a machine that could fuse, not just a demo fusor. I have yet to go over to C&H to see what they have, and I won't be able to until Thursday. Neon sign transformers look to be relatively cheap ($60) and can definitely provide enough punch. The other components in the circuit (high-voltage diodes, bleeder resistors, filter capacitors, Variacs...) will have to be scrounged as well; right now the best looking bet is C&H, although, again, I don't know what stock they have of any of these things. (They mostly carry electromechanical and optical devices.)
This is a sorry state of affairs. I have yet to get in contact with any machining shops to see what the rates are, or even to see if they'd be willing to do a little charity work as part of a sponsorship deal. If I'm lucky, the majority of the machining will be things that I can do myself (drilling holes in aluminium plates, bolting things together, etc.), but it looks like there could be some serious business involved when it comes down to creating the electrode grids. They need to be welded for safety reasons--I'm not willing to risk a grid meltdown due to electron bombardment, especially if I run the device in front of the class.
I don't have a lot of progress here, either. There are a couple of surplus sources I know, but I don't personally know anybody that could help me. I've taken a look at a couple of electronics-flea-market fests, but my involvement with the school musical means that my next three weekends are filled, effectively killing this route of discourse. I will have to rely on references from other people, if I'm to get any parts from personal storages or collections. I'm also beginning to get slighty annoyed at the lengthy process of shipping--man, couldn't they make overnight the normal, non-expensive option?! It takes any parts I order about a week to a week-and-a-half to get here, due to the fact that a lot of these companies have no online processing and require a mailed check or money order.
This has been coming along well. I know the general gist of the D-D reaction process, the results, and the hard numbers behind it, mostly thanks to Wikipedia and Google. I'm looking for authoritative scientific journal studies on it, but it seems that JSTOR and a couple of other journal aggregators don't have any content pertaining to fusion at all. I'll try and look at alternative sources. Also, the HEAS tapes (from the folks over in Virginia, specifically Richard Hull) should've come in yesterday, but the post probably delayed it 'till tomorrow. Those should be a very handy reference for this machine and its specific details of operation.
Overall, I think I'm in pretty good shape. My preception of this project quickly oscillates from "Dude, this is f---ing impossible and insane, it'll never get done!" to "Oh, this is trivial, it's just a bunch of components connected together," depending on my mood and circumstance. I suspect that the truth is somewhere in the middle; it'll only be known when the deadline slaps me across the face. If anything, I already have the makings for a pretty good research paper here--I could, at the very least, write out 5 major issues and details of this project, with a page each.
It would still be better, however, for me and everybody else who doubts me, to see this thing in operation producing some level of neutrons.
My friends have already begun to refer to this process as me "pulling a cyan"--a massive, insane task to do in ridiculously short amounts of time, yet I still get it done. And well.
Odd pump behavior...
OK, the pump is beginning to act up. When cold, the pump's oil level is below the scale--you'd think it needs refilling, right? The thing is, when I filled it hot yesterday, I filled it with the same amount of oil that it always had, and it ran all through yesterday without incident. Curiously, when you run it, the level comes back on the scale to where it was when I filled it.
But, there's some non-savory behavior that comes along with this; the pump seizes on startup, as it (presumably) gets the oil into circulation. Unless you hand-spin the drive wheel beforehand, the drive motor will stop because of overload.
There are no oil leaks, as far as I can see. No dripping, no puddles, nowhere on the pump, not even below the drive motor or within the belt-drive guard. If it's leaking, it's leaking through solid metal and then disappearing.
I tried putting oil in while it was cold, and the end result was a running oil level far above the acceptable limit. I haven't any idea what to do.
I updated the pictures, hooray!
On other fronts, Professor Charles Barnes, a professor emeritus over at Caltech, said he wouldn't mind meeting me about this project--I should be able to meet him Thursday (ah, the perils of a crowded schedule).
Pump oil changed and running.
I changed the pump's oil--it was a couple of shades darker than it should be, and it had swirls of black impurities. It's too bad that I only had about half a quart of oil--not enough to force flush. I'll order a couple of gallons from Duniway Stockroom when I get the chance, along with some cleaning fluid.
I'm suprised at how quiet it is--about half of the noise is coming from the motor, and the other half is just the intermittent clanking of the pump (it sounds like the vanes are sticking).
Since I didn't have the "correct" vacuum cap to deadhead it, I'm currently running it with a metal cap (shielded magnet holder) combined with pieces of household rubber glove as a gasket. It seems to be up to the job, though; there's no excess mist coming out of the exhaust port--pressures are below 10 Torr.
Slowly crawling along...
Success! I've been able to render the aforementioned pump from Poly's science department (a Welch 1400); they're so nice and helpful. Thanks, Mrs. Schmitt!
It seems that it's in pretty good operating condition; oil is clear and there aren't any bad noises. Unfortunately I have no vacuum equipment to test this on, so I can't tell how well it's working. I might be able to lay my hands on spare vacuum gauges, probably the thermistor type or Bordon type, but those are definitely better than nothing.
I'm also looking for a 1/2" pipe barb to 1/4" pipe barb vacuum adaptor--the fitting currently installed on the pump is the former, and the only length of vacuum tubing I have has an ID of the latter. So far, all of my searches have just yielded lots and lots of flange adaptors--while nice, they're not what I'm looking for...
It's begun to sink in that I'm building this thing; there's no looking back. My workspace is already starting to get cluttered with the pump on it (I hadn't realized that it was so big!); it's a big startling reminder of my future path.
I've also started to get in contact with people who might be able to help me--the people in the science department, are, again, of the utmost help.
Oh, and the HEAS tapes are on their way. Yippee.
I'm in panic--utter panic.
Ok. So far, I've done nothing but research--marking today, I will have a month to construct a fusor. I emailed Brian McDermott a while back; he said that he could do it in less than two weeks given that parts were freely available. Hopefully, I might be able to find somebody at Caltech, or somebody at all, who can help with the various facets. There's no way that I can do this otherwise.
In other news, however, I've ordered three HEAS tapes about fusion/radiation; they should be here by this Saturday. This should give me a lot of insight as to how I can pull this off.
Most likely, I'll start off by building the two grids; there's several machining shops in my vicinity, and there's a welder drive unit over at school. I don't know whether or not somebody over there can actually use it, though; it's entirely possible it's just left over from ages past and is taking up space. Preliminary observations lead me to believe it's a Millermatic 130, a "wire welder." ... No, come to think of it, only spot welders can weld spots. The other types are for joining long sheets, aren't they?
The vacuum supply at this moment is one of my less troubles. Here, I have some sourcing--if I can talk to the Polytechnic science department, I'll be able to get their vacuum pump and bell jar. The vacuum pump they've got is a Welch DuoSeal 1400, which is rated down to a base pressure of 0.1 micron. It'll work, especially if it's been in good maintenance as it looks.
I might be able to scrounge up a nice powersupply at C&H, a surplus store; it's got a lot of neat stuff in their retail outlet that I think might be able to serve me well. It's close, too, just in the vicinity of Poly--no worries about transportation there.
My classmates have been fretting at how bad this project will make them look; they're asking me to go last in order of presentation At this point I'm not even sure I can finish by the deadline.
I've also run into a few people, mostly interested classmates and parents, who say this is impossible; fusion could never be within the reach of the household experimenter, especially not a high-school freshman.
In the time between the last post and this one, I've also managed to clear off the sole workspace I have in this damned small garage--it's about 3 feet by 4 feet, and there's two shelves of that size. I hope that's enough.
It's doable. (Proposal submitted.)
This is what I handed in to my physics teacher, Mr. White. So let it be done.
Start off insane, end up dead...
I just received a science project assignment, and the gist of it is this. We're supposed to pick from 3 options: a research paper, an experiment, or a Rube Goldberg machine. I've been interested in Hirsch-Meeks type inertial electrostatic confinement fusors since last year (8th grade), and I managed to get my ego in the way, saying that I'd build one. I reneged on that promise, of course, but this year I think I have a chance at actually making one. I'm going to do some research and find out about that.