Fusor construction efforts

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Dany_B_Drolet
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Fusor construction efforts

Post by Dany_B_Drolet »

Hi everyone!

This topic is just a ping to the community to say that I haven't abandoned my fusor project, but that I am encountering many difficulties. Of course, the first one is money, since my parents cracked down on me and my lab equipment (thank god I was able to save my glassware) and are now making me pay for most of my stuff (Rent, groceries...). Still, they pay for my studies at my new college (CEGEP, in fact, it's similar to the French BAC and is before university) in physics. Though right now we don't learn physics as much as basic electronic circuits... Which is boring as hell since I've already been studying electronics for the past 4 years.

Anyway, so my second problem is space. I managed to haul over most of my lab in my dorm (because I wouldn't dare call it an apartment even if it costs like one) but now I'm buried in tools and pumps and whatnot. I basically sleep next to my high vacuum equipment, which may or may not be contaminated with unknown chemicals.

And third, time. My studies takes most of my time and getting a few hours straight to work on it is pretty hard, but I'm slowly getting there. I went to my school physics director and asked if they could help me. His answer was: ''we do not have the time, the will, and the budget to help you; the school will not engage itself to help you in any way''. I also asked the lab techs if I could use their high vacuum cleaning room to clean my equipment: '' due to CSST (OSHA) regulations, I can't authorize you to bring any high vacuum equipment inside the school. They might be contaminated". So I simply asked how vacuum systems are cleaned: "I can't really tell you. It's done with dangerous solvents and your equipment might be contaminated with stuff like arsenic." That was exactly the point, but I gave up. I believe I annoyed them.(...)

I got nearly everything for the construction of the fusor itself. The main missing components are the HV high current power supply (for actual fusing, I already have a PSU capable of demonstration plasma), a 2.5'' CF HV feed-through, gaskets including a 19'' L-gasket, 2x 6'' CF gasket and some quick-flange fittings, custom-made bell jar plate (there's a MIG job shop nearby, I'll go see them) and the grid itself, which I still wonder how to do it (again, the shop guys might help).

My current stock list includes: 19'' bell jar with implosion shield, turbopump (Leybold TMP-360) & controller (NT360) (looks good but untested and uncleaned, need to create power cable yet), rebuilt Edwards E2M2 rough pump, old-school belt-drive vacuum pump (more on that in a moment), VCR connectors & pneumatic valves (MDC, looks brand new), CF 2.5'' crosses, corners, bellow, viewport, quickflange roughing line assembly with bellow valve, 6'' gate valve (this thing is a solid 2 feet across block of solid steel. Heavy! And obviously contaminated.), Millipore DeviceNet mass flow controller (looks new with plastic caps; got it for 25$), DeviceNet I/O block, DeviceNet iBaratron, two Pirani gauges, Convectron/Pirani gauge controller,Boron-10 proportional neutron counter (tested working but not tuned), Polon (european) RUST-3 radiometer (HV don't work; need recapping)... And quite some stuff I don't remember.

As for the metrology equipment, I got a trusty CDV-700 GM, an Eberline with a brand new pancake probe, a lonely Ludlum pancake probe and a decalibrated Keithley Ionization chamber meter (made for medical X-Ray detection). Also, I'm building a gamma spectrometer in parallel, using a Canberra series 35 Plus MCA (might be unnecessary with a PC sound card) and a repurposed EG&G Radioflow HPLC LB509 device. I wish to be able to make neutron activation experiments when (& if) I achieve fusion.

Right now, I'm modelling the thing in Solidworks so I can make the framing. I will use T-slotted aluminium extrusion for maximum flexibility. I need to order these anyway because I'm also personally designing a 3D printer in hope of making some cash with the design and update the last one I built by the same occasion.

Yep, three projects in parallel. I'm trying to schedule them right so I don't end up failing all three of 'em.

On another note, I met a guy (now quite a good friend) in my classes, which is quite interested in physics and a beginner DIYer. He's a bit afraid of the complexity of the project, but we might partner up. It's a good thing because a lot of tasks are extremely hard to do by myself and I don't want to be alone while performing some dangerous tasks. I was supposed to go to HEAS with him, but his parents kept him and couldn't afford to go there by myself. I'll see where that goes...

On yet another note, you know the old belt-driven vacuum pump I talked about? Now I bought the thing on ebay for 50$ + 25$ delivery, a steal really after seeing that the best offer I had in Montreal was 1200$(!) for an oil-pissing one. That's 60lbs from California to Canada (via my forwarder). When it came to my workplace, the Fedex guy gave me an oil soaked package. Uh-oh... Opened it and then... Contaminated oil everywhere. After hours of cleanup behind the boss back, I opened to pump to clean the insides when... Mercury! Mercury everywhere! The pump was full of mercury! I don't know the exact quantity, but there was more than thermometers in there. Took me hours to clean it up. Retrieved most of it but some made it down the drain. I filled three buckets of mercury contaminated stuff (including my clothes) and immediately went off to dispose of it properly at an hazardous waste center. There, I was promptly told that they won't take my stuff because they don't take mercury from non-commercial users (???) and to dispose of it elsewhere. I told them there was no elsewhere because they were the only hazardous waste disposal site in the whole sector. They then promptly close the door in my face (!!!). At this point, I was boiling with rage so I just tossed the waste buckets at them and took off... What the hell?

I guess that wraps up my latest efforts into putting together my fusor...

Got an album with my stuff here. I don't want to load the forum with pictures of my crap, so I just link my GDrive folder. There, you can also see my "dirty vacuum" vacuum setup with a smaller bell jar. I want to use it as a desiccator and for other "dirty" experiment with vacuum. It's the setup driven by the belt pump.
Ignorance is never better than knowledge
-Enrico Fermi
-------------------------
Fusor project status: Stalled. Most components acquired.
Financial problems forbid me to spend any more penny on it for now.
JakeJHecla
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Re: Fusor construction efforts

Post by JakeJHecla »

I'd guess the mercury came from the roughing pump being used to back a mercury diffusion pump. Other than that, I can't think of a plausible source. Do be careful on the decon work, mercury poisoning is nothing to laugh at.
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Richard Hull
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Re: Fusor construction efforts

Post by Richard Hull »

Well how green we all are. Decontaminate a vacuum pump!!?? Mercury contaminated clothing in the trash!!!?? Oh well, We are all more terminally brain washed and brain dead than any amount of mercury poisoning might cause in effect. Wow! OSHA greenie weenies.

As a kid we used to have lots of mercury an use our little bare hands to rub mercury into pennies to almalgamate the copper into dime look alikes. It took about 1 hours of rubbing to get 10 pennies shine like dimes. We had three boys and two girls involved in that enterprise.

My early vacuum pump cleaning consisted of dumping the old pump oil over an old bush, at its base, in the yard that just refused to die. It didn't seem to do the job for we were cutting it back for years afterwards. Later I used old motor oil after I changed my own oil in my Lincolns. Still no death of that holly bush.

We would get on our bikes and chase the cool old DDT truck that sprayed huge volumes of DDT up into the trees to get rid of the japanese bettle investation in the late 40's and early 50's. ( I can still remember that smell). I lived in one of the moderately high fallout areas on the east coast due all of the 15 year long early bomb tests and breathed all that isotope rich air.

I remember the hand operated "Flit" sprayer pump that we used and we bought Flit by the gallon. I think ESSO produced it and it had DDT in it and I used to spray our grape arbor and the back porch to get rid of flies and mosquitos before we would go out at night to sit and escape the summer evening heat. The oil would be all over me after a "flit session"

Here I am much, much later with none of the fashionable allergies of the day attributed to all the stuff I snorted, absorbed, waded around in as a young kid.
While I might have more common sense now and a bit more caution, I will not submit to the fear and hype foisted on me by modern society. I grew up where their was not one kid with an allergy to peanut butter (a staple to all kids of the 40's-60's). A never knew a kid with an allergy while I was growing up and we had a ton of baby boomer kids in my neighborhood.

Enjoy the horror of modern (panty) waste disposal. Follow those regs and keep safe and healthy and still, die all the same of something, whenever.

I am glad you are still with us in spite of your battle for space and assistance at the local level.

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
JakeJHecla
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Re: Fusor construction efforts

Post by JakeJHecla »

Danny, though I doubt you've put yourself much danger in the cleanup measures you've taken so far, please be careful running the pump in regards to ventilation. Here's my "greenie-weenie" reasoning:

1) Mercury is not particularly dangerous on contact, but is easily absorbed through the lungs. It's a cumulative toxin and is well known to have interesting psychological effects.
2) Your vacuum pump should run at between 25-35C under good conditions. I've had mine hit over 40 when dealing with a poorly sealed chamber.
3) Mercury has a high vapor pressure for a metal. See page 17, table 4 of: http://www.physics.rutgers.edu/~eandrei ... R.6643.pdf
- a) For 35C, Hg's vapor pressure is 2.3X10^-7 mol/L (unconventional units, but you'll see in a second where I'm going)
4) The IDLH (immediately dangerous to life and health) level of mercury is 10mg/m^3 (see: http://www.virginmercury.com/pdf/MSDS.pdf ). This value indicates a level "likely to cause death or immediate or delayed permanent adverse health effects or prevent escape from such an environment" according to NIOSH.
- a) Converting the units of the vapor pressure above indicates a concentration of ~46mg/m^3 at equilibrium (2.3E-7mol/l * 200.59g/mol*1000l/m^3*1000g/mg) in air, which is almost five time the "immediate danger" level
5) While I realize this assumes a closes environment, running the pump in an smaller space (such as a basement or a student's dorm) for an extended pumpdown will approximate such a situation. Running a pump for hours on end is not unusual, and this is in fact ideal for evaporating the remaining mercury adhered to surfaces in the pump.

From the above research, I believe running the pump indoors is a poorly-advised plan. I would advise using an open garage a with a strong fan going. Also, if any backstreams into the turbopump, you can kiss all that shiny aluminum goodbye.


For reference:
http://www.nlm.nih.gov/medlineplus/ency ... 002476.htm
http://en.wikipedia.org/wiki/IDLH
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Rich Feldman
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Re: Fusor construction efforts

Post by Rich Feldman »

Jake, I sincerely applaud your quantitative approach to toxicology. No need to be too alarmist, or too cavalier, about a well-understood material. Medical records include cases like a teenager who presented with acute mercury poisoning. He'd spilled a bunch on his carpeted floor, more than a week earlier. Saturated vapor even at 20 degrees C is not something you want to breathe all day.

I did the quantitative thing after one of my McLeod gauges arrived with spilled mercury in both inner & outer cardboard boxes, plus the crumpled newspaper padding. No glass had been broken. The seller had given up on safely extracting the drain plug, and then the package had been tilted in ways that dribbled some Hg through the dessicant tube and out the vacuum inlet. Outdoors, I uncrumpled and shook every sheet of newspaper over a big plastic mortar-mixing tub.
DSCN0147.JPG
Must push back a bit on your conservative analysis. To reach that IDLH level in a basement or dorm room of 30 cubic meters, you would need to be evaporating 300 mg of mercury in a time interval similar to the air-change time of the room. For Hg to condense on turbopump blades, wouldn't its partial pressure there need to exceed the saturation pressure at the blade temperature? Sort of a dew point thing. For many decades, mercury was the standard working fluid for diffusion pumps in laboratories and industrial processes. Light bulb and vacuum tube factories? The Amateur Scientist column in C. L. Stong days, which lasted well into my tinkering years, presented fabrication (by glassblowing) and operation of Hg diffusion pumps.

Restricting the disposal of mercury thermometers and automobile-trunk-lid tilt switches is important because of "what if everybody did it?" considerations. Like urinating on a wall downtown. If Dany were to simply discard his contaminated clothing, IMHO that would be like some hobbyist venting Freon from a discarded air conditioner. Earth's atmosphere is pretty big, and America's industries legitimately release on the order of 100 tons of mercury each year. Mostly by burning coal. I wonder how many fluorescent lamps get broken in Dany's town, accidentally or on purpose, each day?

They say that Brillo-like copper scrubber pads, and powdered sulphur, can be used to clean up mercury that's stuck to smooth surfaces. We all know that metal parts can be made too hot to touch, simply by placing them outdoors on a warm sunny day. Perhaps inside a clear or black plastic bag. Not inside a hot car, if your purpose is to evaporate residual mercury. :-)
hg.JPG
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All models are wrong; some models are useful. -- George Box
JakeJHecla
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Re: Fusor construction efforts

Post by JakeJHecla »

The scenario I presented is extreme, and I made that clear in the post, but I feel it highlights the danger of the situation if it's handled poorly. Even if the air contamination is 2% of the concentration that I presented, it's still enough to cause "observable teratogenic effects [in rats] after 24 hours" (NIOSH readings for 1mg/m^3). As for the volume in the pump, Danny did not make it clear how much Hg was present. It could have been a few beads of quicksilver or a few hundred grams. Only he knows for sure. As for Hg condensation, I'm well aware of how it works, and I'm sure you can imagine more than one situation in which the turbopump might be cooler than the backing pump to facilitate this process. I'm personally more worried about Danny's well being than that of the pump
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Rich Feldman
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Re: Fusor construction efforts

Post by Rich Feldman »

Hey Jake, I do agree with your words of caution. Dany should certainly get the pump well cleaned out before running it indoors, or even leaving it taken apart indoors. Richard Hull would be OK -- he vents his backing pump to outdoors rather than see, smell, and clean up after oil mist.

To complement the IDLH value, let's consider the threshold limit value (TLV).
The regulatory agencies consider that to be tolerably safe for workers to breathe for 8 hours/day.
ACGIH and NIOSH put that at 0.05 mg/m^3. http://www.cdc.gov/niosh/pel88/7439-97.html
Not that you or I want to endure that without being paid to be there.

Got carried away with the quantitative analysis tonight. Checked your data point. My result was 43 mg/m^3 of Hg in saturated air at 35 degrees C. (The air density is down to about 1146 g/m^3 at that temperature.)

Here are some more points, by unreviewed calculations, for air temp of 20 degrees C:

The "safe" TLV value (0.05 mg/m^3) is 41 ppb mass fraction and 6.0 ppb mol. fraction.
Partial pressure of Hg is 4.5e-6 torr.
In a room of 30 cubic meters, you could evaporate one mercury bead 0.6 mm in diameter for each time the air was changed.

That "immediate hazard" value of 10 mg/m^3 is 8.3 ppm mass fraction and 1.2 ppm mol.fraction.
That's a 3.5 mm diameter ball of liquid mercury per 30 cubic meter room.
Partial pressure 9.1e-4 torr, which is equilibrium with liquid Hg at 17 degrees C.

Another point of reference. Couple years ago I spilled less than a fever thermometer of Hg on concrete garage floor. Cleaned it up except for some 0.6 mm or smaller beads that I could see down in a crack.
They were still there, looking about the same, a week later. I must remember to check in the morning to see if they're gone yet.
All models are wrong; some models are useful. -- George Box
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Richard Hull
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Re: Fusor construction efforts

Post by Richard Hull »

Indoor oil mist on a long running pump is a very serious issue and you need to do a bit of heroics on making sure you are not exposed constantly. Either vent it to outside, (best) or get a very serious oil mist trap and filter.

Mercury can be handled readily by the user, as well, but don't live your life in a mercury environment. It's all common sense. Use open mercury in devices and processes out of doors. Store in tightly sealed, heavy walled polyethylene or polypropylene bottles in an out building. Never spill any (critical).

I have used asbestos a good bit to hold small items while welding or silver soldering. I have zero fear of handling it in the form of a wet ball with my bare hands, regularly. However, like the oil mist, I would not want a job in the industry of either installing it in ceilings (old days) or disposing of it (now).

Like radiation, the time of exposure and the intensity of the exposure are key factors. No need to fear short individual exposures to oil, mercury or asbestos.
Most all you hear is hype and is related mainly to serious health issues occuring in long term industrial and worker related exposures.

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
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Dany_B_Drolet
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Re: Fusor construction efforts

Post by Dany_B_Drolet »

Interesting discussion. I wanted to check out what was the real danger with the mercury amounts I was handling and how to handle it properly. Never found out. All I saw was obvious hype and CONSULT A MERCURY DISPOSAL PROFESSIONAL (in caps, obviously). It's basically what happens when you check a medical symptom on Web M.D.: go see a doctor. Yeah, very useful.

I'm not one to go mad with safety procedures, I just thought that avoiding exposure as much as possible (ALARA, I guess) made sense. And my clothes were so full of that disgusting oil (which was so contaminated with crap it had the consistence of jelly) that I threw out everything.

I estimate the amount of mercury I handled that day to a ball of nearly 30mm diameter. Part of it is now in a screw-cap tube inside a zip-lock in my room (in my ventilated ''hotbox''). I cleaned the contaminated pump in the high pressure cleaner glove box at my workplace after removing the Hg beads of the reservoir walls. I think it should be really clean now.

That pump will not be connected to my turbo. I keep it only for chemistry and otherwise general-purpose vacuum needs. I don't trust the thing enough. I also doubt I'll making it run for more than a few hours at a time. Unless I decide that sleeping next to a live experiment is a good idea. The pump I will use with the turbo is the more recent but likely less powerful Edward.

I understand that it's not generally a good plan to run such a setup in a dorm, but right now, it's my only plan. I'm definitely looking for another apartment ASAP, something around a 2-1/2, which will allow me to have my lab in one room and everything else in the other. Though getting or building a fume hood would be a good thing. Last time I did something that started to fume, I had to do it in my bathroom with a gas mask.

By the way, I didn't have sulfur or anything to pick up the mercury. So I improvised and used a turkey baster to pick up the bigger beads and duct tape for the smaller ones.
Ignorance is never better than knowledge
-Enrico Fermi
-------------------------
Fusor project status: Stalled. Most components acquired.
Financial problems forbid me to spend any more penny on it for now.
Ross Moffett
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Re: Fusor construction efforts

Post by Ross Moffett »

At the least, run the exhaust out your window. Does your dorm at least have a window?
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Dany_B_Drolet
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Re: Fusor construction efforts

Post by Dany_B_Drolet »

A dorm without a window? Now that would be depressing... Well, yes, I can do that. I've been thinking about running a flexible air duct from the window to the workstation for the fume hood. I guess it would be a good idea to run a parallel line to it from the pump exhaust.

I guess an image is worth a thousand word.

Image
Ignorance is never better than knowledge
-Enrico Fermi
-------------------------
Fusor project status: Stalled. Most components acquired.
Financial problems forbid me to spend any more penny on it for now.
Ross Moffett
Posts: 89
Joined: Mon Aug 26, 2013 10:24 pm
Real name: Ross Moffett

Re: Fusor construction efforts

Post by Ross Moffett »

Wow. I hope that's long-term habitation. I couldn't imagine having moved that much stuff to my dorm. Nice workstation!
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Dany_B_Drolet
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Re: Fusor construction efforts

Post by Dany_B_Drolet »

I must say, I'm impressed by your efforts.

Turns out I was checking fume hoods just recently using my real name on trading websites, looks like one of the suppliers found me on these forums.
Ignorance is never better than knowledge
-Enrico Fermi
-------------------------
Fusor project status: Stalled. Most components acquired.
Financial problems forbid me to spend any more penny on it for now.
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