Archived - Tom McCarthy's Fusor Efforts

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Tom McCarthy
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Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

Hey all,

I recently got my first part, it's not so much a part but well..It's a start!

The part I got is a 20Mhz, Kikusui, twin channel oscilloscope, model is COS5020. I got it for free of a man named Richard Tarr, he was selling it on an Irish site and I threw him an email telling him about the Fusor and he was very happy to donate. Richard himself is a software engineer with a bit of expertise in electronic engineering, from what I can tell. I collected the 'scope with my Uncle last week, RIchard did not have any probes left, nor a power cable, but I used one of the power cables from one of my guitar amps and it turns on, must be a good sign? I'll try and source a probe or two in the next few days.

The other reason I was in RIchard's area of the country was that I was visiting Dr. Patrick McCarthy of University College Cork. Dr. McCarthy is a plasma physicist who splits his time between Tokamaks in the Max Planck Institute For Plasma Physics in Germany and his own research in Cork which focuses on magnetic confinement fusion. He himself has a sort of experiment/machine akin to a demo Fusor, but not quite.

The machine has a large, two-part chamber, which is evacuated by a turbo and roughing pump. Turbopump cost €13,000… One part of the chamber is not used anymore, but has a picket fence of magnets surrounding it from former experiments. The other, used part, has a tungsten filament in the centre, connected by feedthrough to Dr. McCarthy's various supplies. A stack of 3cm rare earth magnets on either side of the chamber creates a confinement "bottle" for the plasma that is created within. Helium-4 enters the chamber and is negatively ionized. Dr. McCarthy's power supplies have a low enough voltage but fairly high amperage, they generally have a maximum of c.100v and c.100A. Other than the Helium-4 being negatively ionized and a plasma forming, another interesting thing happens. Two different "types" of electrons emerge inside the chamber: Hot and cold, this is due to the Maxwell distribution as all electrons enter the chamber at the same energy (from the power supplies), but they gradually exchange their energies and so you have two different streams of them.

I'll most likely be visiting Dr. McCarthy again in the year, he has also agreed to try and find some parts for me.

Cameron Key, if you're reading this, please don't mind the post-name-steal.

Pics are linked, if anyone has advice on how to get the file sizes down, it'd be much appreciated and I'll try to get them posted here.
Cheers,
Tom

http://imgur.com/a/Jc69U
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Re: Tom McCarthy's Fusor Efforts

Post by John Futter »

Tom
Download Irfanview
It is a free picture viewer that allows resize/resample to reduce pic sizes to waht this board likes
Tom McCarthy
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Re: Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

Thanks for the tip, John. However, I cannot use Irfanview as I'm on a Mac, found a tip that showed me how to do it with Preview though on a post on some forum about it for Mac.

Tom
Dr. McCarthy's control panel.
Dr. McCarthy's control panel.
A stack of 3cm rare earth magnets.
A stack of 3cm rare earth magnets.
Close up pic of top of control panel.
Close up pic of top of control panel.
Bottom of control panel.
Bottom of control panel.
Pumps and a bit of the vacuum line.
Pumps and a bit of the vacuum line.
Better pic of pumps.
Better pic of pumps.
Chamber with Langmuir probe.
Chamber with Langmuir probe.
Chamber, red metal is picket fence of magnets surrounding unused part.
Chamber, red metal is picket fence of magnets surrounding unused part.
Helium tank.
Helium tank.
Small electronics set-up for measuring current, voltage etc. inside chamber.
Small electronics set-up for measuring current, voltage etc. inside chamber.
Some of Dr. McCarthy's spare parts.
Some of Dr. McCarthy's spare parts.
Me and Dr. McCarthy
Me and Dr. McCarthy
Oscilloscope front.
Oscilloscope front.
Oscilloscope back.
Oscilloscope back.
Oscilloscope.
Oscilloscope.
Me and Richard, sorry for the bad quality.
Me and Richard, sorry for the bad quality.
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Richard Hull
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Re: Tom McCarthy's Fusor Efforts

Post by Richard Hull »

Thanks for sharing you visit! You are doing the right thing. Visiting people and making new contacts is a real plus. You never know it what ways they may contribute directly or indirectly to your effort and you get a bit of education on the journey.

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
Tom McCarthy
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Re: Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

It's all about who you know, isn't it? Dr. McCarthy said he might be able to get me some parts - some of his conflat, maybe something else if I'm lucky - and he'll make an effort to get me into another lab in Dublin where they have multiple labs focusing on plasma research and analysis.

I'll try and keep you guys updated with pics from any visits, but it'll probably be a while before I get into another lab, hopefully not too long though.

Tom
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

Helium-3 tube arrived today...With a customs charge of €42 which I thought I had avoided. It's 13" long, shipped in good condition. I bought if off cgroat3573 on Ebay (http://feedback.ebay.com/ws/eBayISAPI.d ... llFeedback). Jack Rosky and Scott Moroch put me on to him after they bought their tube from him. I think he also supplied Connor Givan's tube. Keep an eye, he puts them up every so often and will go to huge efforts to ensure a happy buyer.

Quick question regarding it: I'm certain that it'll take a 2000v bias, but will a 1000v bias be suitable for neutron detection? Example product (which I plan on buying): http://www.gammaspectacular.com/gamma-s ... s/GS-1100A

Tom

Pics:
Tube with 12" ruler.
Tube with 12" ruler.
Blurry photo of label on tube.
Blurry photo of label on tube.
Packaging the tube arrived in.
Packaging the tube arrived in.
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Richard Hull
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Richard Hull »

Regardless of what the tube says, it is always a good idea to approach the recommended bias from below.

Once you have a known good , charge sensitive, pre-amp and detection electronics, the norm is to place the tube in a moderator, get a source of fast neutrons and bring the bias up until you get detection pulses.

This is not the forum for this discussion. Check out Carl Willis' videos on setting up a 3He tube. (radiation forum)

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
Tom McCarthy
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

I'll check them out, thanks for the reply.

Tom
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

Received my Hydrocar with PEM cell - snatched up for less than €50. Tried putting it together, but the plastic tubing splits at the ends whenever you push it on the nozzles, I'll play around with the fuel cell itself later with some H2O.

I also received my Edwards Speedivac valve (LB1A). I dismantled it and it seems fine - keep in mind I have no experience with these valves. I plan to use it for the deuterium admittance system, but in case it does not work I have a Granville-Philips valve bought too. The disc showing what % the valve is open is not in sync with the actual knob, it can be turned by hand without turning the knob but will turn with the knob too - I'll just have to turn it to 0 and make sure nobody touches it whenever I get to use the thing.

Also, for those interested, I'm getting a 12" spherical chamber manufactured for what is essentially free. Hivac Engineering (http://www.hivac.co.uk) have agreed to manufacture the attached Kurt J Lesker sphere for me and leak test it for only the cost of the flanges, which they receive at a discount and will apparently be well within my budget. I'm also going to be making a presentation to the Trinity College Dublin (http://physics.tcd.ie/applied-physics/) Applied Physics Research Group. Their research is focused on the topics of nanotechnology and clean energy. The guys there were pretty hopeful that I might be able to get some spare vacuum stuff that they have lying around on "indefinite loan" when I go for a look around their labs.

Tom

Pics:
Needle valve from top.
Needle valve from top.
Side view of needle valve.
Side view of needle valve.
Needle valve dismantled.
Needle valve dismantled.
Oxygen side of PEM cell.
Oxygen side of PEM cell.
Hydrogen side of PEM cell
Hydrogen side of PEM cell
PEM cell in hand for size comparison.
PEM cell in hand for size comparison.
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

More parts: Victor VTS452D hydrogen regulator, Granville-Philips leak valve and a Pirani gauge and sensor - Edwards model 503 controller with PRL10k sensor. The gauge has a range of atm. to 1x10^-4 mbar = 7.5x10^-2 microns.

When it arrived, the leak valve's knob wasn't turning the meter. Thanksfully, the meter wasn't broke and the knob itself was simply jamming. A bit of dismantlement and a few sprays of WD-40 sorted the problem. The valve appears to be fine other than that. The Pirani gauge powers on, but I have no means to test as of yet. There doesn't seem to be anything wrong with the regulator either - I hope not anyways!

Regulator manual: http://victortechnologies.com/IM_Upload ... lators.pdf
Leak valve manual: http://www.mksinst.com/Docs/R/GP-203Lea ... 26-MAN.pdf
Pirani sensor page: http://www.edwardsvacuum.com/Products/D ... /View.aspx

I couldn't find the 503 manual, anyone have a link?

Thanks,
Tom
Leak valve.
Leak valve.
Leak valve connections.
Leak valve connections.
Hydrogen regulator.
Hydrogen regulator.
Pirani gauge.
Pirani gauge.
Rear of Pirani gauge - 7 pin connection for sensor.
Rear of Pirani gauge - 7 pin connection for sensor.
Pirani gauge sensor.
Pirani gauge sensor.
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

Lots more equipment; namely an Edwards RV3 mechanical pump, an Oerlikon-Leybold Turbovac 151 (with controller and cables) and Gamma Spectacular neutron detection set-up. I've also got my vacuum chamber sorted out, a 12" sphere with 10 CF ports. It's being made by [url]hivac.co.uk[/url] and should be here some time in October. Ordering deuterium soon enough and more vacuum fittings en route. Need to get some more gas fittings and vacuum valves, but that's all really.

The Turbovac is newly refurbished, straight out of the box and the RV3 has only seen some moderate use. The previous owner said it should be pulling optimum vacuum after an oil change/clean-out.

Does anyone know anywhere to get a 3" sodium iodide scintillation crystal? There are BGO ones and some other types on sale on Ebay, but I'd prefer NaI.


Tom
Attachments
Beryllium, 2 grams from Poland.
Beryllium, 2 grams from Poland.
Oerlikon Turbovac straight out of the box.
Oerlikon Turbovac straight out of the box.
Tungsten wire, .6mm diameter and 20m in length.
Tungsten wire, .6mm diameter and 20m in length.
24Kg, quite a lump to bring up and down stairs.
24Kg, quite a lump to bring up and down stairs.
Edwards RV3 pump, hoses attached came with.
Edwards RV3 pump, hoses attached came with.
Photomultiplier specs.
Photomultiplier specs.
Photomultiplier tube face.
Photomultiplier tube face.
Optical grease, 10ml.
Optical grease, 10ml.
KF16/10 centering ring and KF25 reducer.
KF16/10 centering ring and KF25 reducer.
Info on HDPE moderator.
Info on HDPE moderator.
Gamma Spectacular set-up.  Custom pre-amp on left, 2000v bias on right.  He-3 tube can be seen in HDPE moderator.
Gamma Spectacular set-up. Custom pre-amp on left, 2000v bias on right. He-3 tube can be seen in HDPE moderator.
KF adaptors for Pirani Gauge.
KF adaptors for Pirani Gauge.
Tom McCarthy
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

Been quite a while since the last update...There's been a little and a lot of progress at the same time. As stated before I've got 95% of the parts (only need to order deuterium + related piping) and I'm pretty much ready to go. I've been testing my fore pump and am about ready to hook it up to the chamber.

The guy who's giving me the power supply is keeping it until I've moved into a 3rd-level for supervision - This has been a bottleneck in progress for the past few weeks, but it looks like I'll be moving the setup to NUI Galway under their engineering department when all the safety items are cleared. I've also had trouble ordering deuterium, but I've been told it should be relatively easy to procure when I'm in a University.

My chamber's almost fully bolted, got the viewport and a load of blanks on and am going to fully blank out the other ports to test-run the vacuum pumps. Currently waiting on my boxing trainer (Works in a very good metal-work shop) to get back to me with some prototype grids - got 0.6mm tungsten wire as advised in the FAQs, but he's not sure how weldable it's going to be..

Hopefully I'll get moving a bit faster on the project now, looking to complete before June.

Tom
Chamber
Chamber
RV3 at the bench.
RV3 at the bench.
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Richard Hull
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Richard Hull »

Super impressive chamber! Good luck with the future fusion 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
Tom McCarthy
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

I knew it had been a while since I updated this thread, but didn't realise it was that long.

I have an awful lot more equipment now - deuterium, needle valve, swagelok connections, flow meter, orifice, Hb feedthrough and power supply (no cable), turbopump and roughing pump all ass,bled and pumping to 10^-6 as measured by Penning and Pirani gauges. Neutron detection also here.

Today I received a 6" CF throttle valve, exceptionally well packaged. It's pneumatically actuated, but has a micrometer for throttling. Also have some RG213 pictured that I'm using for a HV cable (many thanks to Rex Allers for his generous help, and also to Jeroen Vriesman and his fellow Dutch experts) and the HV supply I'm using.
IMG_1772.JPG
IMG_1771.JPG
image.jpg
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Richard Hull
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Richard Hull »

When you are finished and working, this will be a really sweet fusion system. Taking it slow and easy will allow for a system that has a far better chance of success out of the gate.

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
Tom McCarthy
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

Thanks Richard, looking forward to getting it working.
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

I just finished leak testing my gas line and it’s in place now. Dad and I put together the clamp arrangement that holds the D2 lecture bottle in place. He welded it, as I have next to no welding experience.

My next step is to complete my RG58 HV cable, and connect my power supply to ballast resistor and then to feedthrough. I also have to put together a little HVPS control box. Handily, the power supply has voltage and current readout and control I/O. Getting there, bit by bit.

Also, not directly Fusor related, but I came upon a CNC lathe. It’s older than I am. I was told that the motors, mechanics etc. are good, but there’s something up with the software. Will boot it up and try and get it working as soon as I achieve fusion.
111453D0-E2F0-492A-A801-E30EAF422C21.jpeg
500531EE-F613-43C6-BF67-5E24FF209FD5.jpeg
5D05D460-7C09-4C60-91B4-85E889100C0F.jpeg
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

I achieved plasma this weekend, on a run less than a minute long. It followed from wiring up and testing my high voltage line and supply.

The high voltage line consists of:
a DIY connector for the Matsusada supply
RG213 coax
100k, 100W resistor immersed in motor oil
grounding lugs/wires
Feedthrough and machined connector.

Also, though not shown in the pictures below, a 4" sewer pipe is placed over the exposed feedthrough and aluminium bar.

To control the supply I use the supply's I/O interface - connects to a panel I made myself, with 10k pots and 0-10v LED meters.
Voltage - varied 0 to max 6kV.
It drew a large current though, maxing out the supply at 20mA. Is this normal? My current meter was showing 9.99, so either I've wired up the control panel wrong, or the plasma current is very large. Perhaps there's some arcing going on, but I couldn't hear anything.
Pressure: ~10 microns.

When I return home next weekend I'm going to do another few runs, hopefully fusion too as I've the deuterium line in place already.

There's a video of the full run at this link - https://drive.google.com/file/d/1v7t4MO ... sp=sharing
It was too large to attach in a zip.

Many thanks again to the Dutch - Jeroen, Jerome and company that helped me out, and Rex Allers for his advice on the high voltage wiring.
plasma_1.png
hv_connector_duinlab5.jpeg
grounds_duinlab4.jpeg
fusor_duinlab1.jpeg
feedthrough_duinlab3.jpeg
ballast_duinlab2.jpeg
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Dennis P Brown
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Dennis P Brown »

I certainly can't speak for your system but in mine, I could easily draw well over 100 ma at startup (max for my x-former was 33 kV and 28 ma continuous) using a 60 K-ohm oil submerged resistor. When the plasma first ignites, resistance can drop to near zero ohms in the fusor and the ballast resistor can do only so much. When this happened (nearly every start up) I'd simply dial back the variac to drop the voltage and hence, the current - often too much and I'd lose the plasma. Then I'd finely adjust the voltage upward until re-ignition, and then have to quickly but using small adjustments re-set the variac to stabilize the plasma. Then I'd use D2 flow to do fine adjustment on the current - this assumes one has already set their fusor's pressure to about its correct operational range (for me, 4 - 9 microns with 5 microns being the most common value.)

Be careful at start up - not dialing the voltage back and allowing the current to run full out could damage your transformer. Trying to ignite the plasma at the lowest easy working voltage is your safest method. The higher voltage systems can really conduct - at 5 microns, I'd get plasma light up anywhere from 18 kV to 24 kV.

Once the plasma remains 'lite', use both gas pressure and the variac to walk the voltage up to your desired setting. Often, the plasma will go weak (too much gas) so one needs to increase the voltage a bit faster or in some cases, finely adjust the gate valve. If current starts to climb too quickly, pressure can be used to control that parameter rather quickly. Setting one's diffusion or turbo gate valve is critical - both to conserve gas and make the system's response to fine gas valve adjustments better.

With experience, you will determine your "sweet spot" for your gate valve, fusor pressure, fine gas valve setting, and start up voltage. Once these are determined, and the chamber is seasoned, start ups are rather easy and so is maintaining the plasma - I could easily run an half hour: but my system did need to be watched - it could easily run away on its own.
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Tom McCarthy »

Thanks Dennis, appreciate the advice. I'm finding it harder than expected to operate the Fusor, haven't achieved a stable plasma at high voltages yet. I don't think I've got a stable deuterium plasma yet, as my D2 flow is too constricted, and I can't seem to throttle my turbo pump enough. The turbo is mated directly to a 6" gate valve. When I run the turbo though, a star mode emerges but is almost immediately extinguished as the pressure continues to drop. See the video at the link below - can't attach it here.

At the end of the video the plasma colour changes to a deeper pink from light blue/grey. Is this indicative of a deuterium atmosphere? I had deuterium flowing into the chamber while the turbo pump was started and think the atmosphere should have been mainly deuterium for a short while. What do you guys think?


Video here.
https://vimeo.com/294171521
Screen Shot 2018-10-09 at 16.23.21.png
IMG_0635.jpg
IMG_0636.jpg
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Richard Hull
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Richard Hull »

Through clear glass, free of deposits, A deuterium plasma is pink to red. It doesn't take long for a view port to become occluded by deposits which shift the color to a great degree. Fusor IV's current color image is black and white using a color camera. This deposit plagues view ports of folks who really run their systems hard. (500 watts+ for hours)

Richard Hull
Attachments
Clean glass video still shot of fusor IV, 2010
Clean glass video still shot of fusor IV, 2010
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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Dennis P Brown
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Re: Archived - Tom McCarthy's Fusor Efforts

Post by Dennis P Brown »

The plasma color looks correct.

If your pressure is dropping too low and your plasma going out, then certainly you need to "throttle" your turbo more via the gate valve since your pump rate is far too fast.

For my system, I'd pump it down, adjust the gate valve almost closed, add deuterium to create a high enough pressure (10 - 20 microns) and 'strike' a plasma. I burn the system and watch the pressure rise at first, then start to fall some. Then I knew I had out-gassed/burned away the worse impurities.

Then I'd close the deuterium leak valve, and just close my gate valve. I'd tighten it 'down' while watching the fusor pressure (in microns.) Just as the chamber pressure would start to rise (no deuterium flow!) I'd 'tap' my gate valve handle just enough to start the pressure to slowly fall. I know this is dependent on your gate valve system but just explaining my method. Then I'd open my deuterium leak valve a specific number of turns (determined by trial and error - after that, this method always worked the same.)

Following all this, I would then slowly dial my voltage up. This was still tricky and could be very unstable. If the fusor "ignited" a plasma, I would quickly lower and/or raise the voltage to stabilize the plasma glow intensity. Somethings I was too slow and it either went out or the current ran away. If it ran away, I'd quickly lower the voltage trying not to extinguish the plasma. If it went out, again, I'd slowly raise the voltage. Once I had the plasma on, I'd have to spend 20 or so seconds dialing the voltage up/down until it stabilized (likely impurities.)

Once stable, the plasma burned fairly steady at my desired current (determined from my fusor electrode design/spacing/setup and past tests: 5 -7 microns.) I still had to closely watch the system - it would run away at times for no apparent reason (maybe a diffusion oil 'burp(?).)
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