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Re: FICS II Planning and construction

Posted: Sat Jul 23, 2016 9:24 am
by Werner Engel
Please see: viewtopic.php?f=12&t=10791
I call it a "plasma backdraft restrictor - design ENGEL" ;-)

And it works.
Meaning, that Plasma can't go through such small diameters.

Which additional DAQ did you order? An isolated one? I thought about taking such a device.

Re: FICS II Planning and construction

Posted: Sat Jul 23, 2016 10:42 am
by Steven Sesselmann

Thanks for suggestion, the plasma restrictor looks like a very nice idea, but I am now so far down the track with my more complicated system, that I may as well give it a go.

I am getting another identical DAQ NI-6008 it will float next to the MFC, I am using two 18V cordless drill batteries connected with voltage regulators so I get +15V, -15V for the MFC and +5V out for the USB optical end connector and DAQ.

The whole assembly fits inside two stainless steel food trays mounted together.

Pressure controller

Re: FICS II Planning and construction

Posted: Sun Sep 04, 2016 8:43 am
by Steven Sesselmann
Another month has gone by and my F.I.C.S. fusion reactor is near enough to complete, I started the project last January so as far as fusors go that's not bad going. The last month was spent troubleshooting why Labview was crashing as soon as the plasma started flickering, so I have been going over every electrical connection and adding some ferrite suppressors, but the problem was most likely caused by two or three grounding points which were slightly loose. Looks like it's all working now, fingers crossed it will work next time I switch it on.

I also have a small leak which I haven't been able to find yet, it's in the order of 1 micron every 3-4 seconds, and should not be critical for achieving fusion, although I would rather prefer it wasn't there. I consulted with a local vacuum company who said they could send out a technician with a portable Helium leak detector for $1400 per day, so thanks but NO thanks.

Using the labview VI interphase I can now achieve a stable high voltage plasma by setting the turbo pump gate valve to almost closed and allowing the pressure controller to adjust the gas flow into the chamber (see video below).

For those of you who have not been following my build, I am controlling the gas flow with an MKS649 pressure controller, floating at high voltage and driven by two 18V batteries. The pressure controller operates on analogue 0-10V signals, which is provided by an NI-USB-DAQ (also powered by the batteries), the DAQ is connected to an active HUB which in turn is connected to the computer by optical cables. Optical USB cables are now readily available and perfect for this kind of use.

FWIW the MKS Model 649 (10 sccm He) would be perfect for mainstream fusors as well, as it would eliminate the need to manually adjust the chamber pressure, you simply adjust the chamber pressure set point with a voltage source and a potentiometer and there it stays, so definitely worth putting a search on eBay for one of these. ... 9&_sacat=0

160904_fics-dry - 1.jpg
Floating Gas Supply and DAQ
Below is a 2 minute video showing the reactor operating in a stable plasma mode. As there is no viewport on this reactor I rely entirely on the instrumentation for feedback. Typically I would start with a higher gas pressure and generate a high current low voltage plasma and then gradually decrease the chamber pressure set point until the desired voltage and current has been reached.
Test Run

Now I have ordered two new bubble detectors from our friends in Canada and fingers crossed I will be back with some neutron data soon.


Re: FICS II Planning and construction

Posted: Fri Sep 30, 2016 5:10 am
by Steven Sesselmann
Hi Guys,

Just a brief note on my FICS progress.

Bubble detectors arrived and I was hoping to do some good runs, but law an behold as soon as I run the reactor with deuterium the USB fails. I carried out multiple tests with air plasma and had no problems (see video above) but for some reason I don't understand, the remote control system goes down as soon as I vent in some deuterium.

I only get as far as seeing a handful of neutron counts from my sound card detector before the USB goes down which kills the process.

This weekend is a three day weekend for us, so I will use the time for probing, maybe I can use my oscilloscope to catch a spike.

Labview with USB DAQ's are nice, but personally I would prefer analogue control over these high voltage machines.


Re: FICS II Planning and construction

Posted: Sun Oct 09, 2016 4:40 am
by Steven Sesselmann
Not sure if I can call this a progress report, because I'm not making much progress, except for in the area of aneutronic fusion ;)

Essentially my machine is complete, everything came together according to the plan, a hollow cathode collider remote controlled from Laview, well almost.

Fibre optic USB connections extending 10 m to my garage allows me to operate it remotely, and after building all the USB hub and DAQ into a copper box for EMF shielding, I can put the machine through it's paces, as long as I use air, and as long as it is not doing any fusion.

It seems to have several modes..

1) High pressure low voltage high current mode, not very exciting and produces no neutrons, I guess it's just like a neon light discharge mode.

2) Low pressure high voltage no discharge mode - obviously no neutrons

3) Medium pressure with intermittent high current discharges and corresponding voltage drops - also no measurable fusion.

4) High voltage (above zener threshold), slowly rising pressure and discharges without voltage drops accompanied by pops in the neutron detector immediately followed by a USB crash (usually the floating DAQ,).
Run data log
In the run data above you can see the typical pattern, voltage stable and zenering, pressure slowly rising followed by a fusion event which causes the USB to crash, this immediately shuts off the mass flow controller and stops the reaction, after a few seconds the USB comes back up and pressure starts rising again, and so it repeats.

Unless I can get the USB to stay up at this point I will never get enough neutrons to use a bubble detector, and will never know for sure what's going on.

I welcome any brilliant suggestions at this stage...


Re: FICS II Planning and construction

Posted: Sun Oct 09, 2016 3:28 pm
by Werner Engel
I talked to people working with remote Controlling in several areas: The told me to use Serial Interfaces between the devices.
People at the University of Vienna are using the following device as a fiber USB Interface (see Picture).

Did you think about choosing different gases to check plasma behaviour?
Helium, Hydrogen?
You can also try to apply a Kind of datalogger (writing data on a Memory Card which you can take out after the incident) inside the Faraday Cage - to monitor USB current and voltage.
And try to increase shielding of the metal box - I'm sure that the seals between the 2 halfs are not RF-tight enough!! There are RF-seals available from several vendors.

Doug was mentioning strage behaviour of DRAM based devices when exposed to Neutron Radiation - I don't think this might be the reason four you fault - otherwise, it would be a great achievement to have that much Neutrons ...


Re: FICS II Planning and construction

Posted: Sun Oct 09, 2016 8:44 pm
by Steven Sesselmann

It can be more challenging to explain why something does not work, that to explain why it does work ;)

We can exclude neutron radiation as a problem, the few pop's in the loud speaker connected to my neutron detector is just the sound of a sleeping dragon.

I am not sure how I should go about changing to serial connection because the NI-DAQ is all USB based, and putting more USB to serial converters could make it worse?

The part of my setup I don't like, is having one USB hub connected to another hub, this daisy chain connection may cause some instability.

Not sure if packet timing is an issue with one DAQ is floating at -50,000 Volts ? Does this cause a relativistic time delay? I did some quick calculations which indicated there may be a relativistic time delay of 50 ┬Ás between the ground based HUB and the Floating HUB, but I am not sure if that would affect the USB signal protocol. If so one would expect the USB to fail all the time when the floating DAQ is at 50kV but it doesn't.

If we look at the plots above I have a short duration 2mA current spike at 50kV which is a short 100W event, I imagine this could generate quite a bit of EMF.

An alternate solution would be to to control the MFC with an analogue potentiometer connected to ground with an acrylic rod, I would then need to build a controller with a stepper motor to remotely control it. Maybe I am taking the remote control part a little too seriously, but I discovered it generates quite a lot of x-rays in certain operating modes, so it feels safer to be at some distance.


References for USB Optical Extenders ... 2-100.html ... d=156.html ... ables.html

Note, the Gigalight cable from China is USB-A to USB-A and has no copper in the cable, the Corning cable has copper wires to power the USB-B end, not sure about the Optics cable.

Re: FICS II Planning and construction

Posted: Mon Oct 10, 2016 5:28 am
by Richard Hull
The moment a fusor or any nuclear accelerator or device has more than 50kv applied X-rays will be the number one health hazard and must be taken seriously. Remote operation is wise and desired. Thankfully, only a microscopic fraction of fusioneers ever see 40kv where shell "shine-through" starts to get serious.

Richard Hull

Re: FICS II Planning and construction

Posted: Tue Nov 29, 2016 9:05 am
by Steven Sesselmann
Haven't posted any news for a while, maybe some of you who don't know me think I have given up, but the old guys here know that this game is not for quitters.

Have had various setbacks as described in earlier posts, but I am slowly fixing one by one, several delays have been caused by the floating electronics, and I have killed a box full of USB hubs, so I am now in the process of rebuilding that part.

In the mean time my system had an annoying vacuum leak, I could pull a sub micron vacuum with my turbo pump on full speed, but when closing off the chamber it would slowly vent at around 1-2 microns per second, which is not great compared to my earlier chambers. I tried spraying alcohol and blowing helium at the various parts without conclusively finding the leak, so eventually I disconnected the chamber and blanked off the other ports, only to confirm the leak had to be in the chamber.

Those of you who followed my build know that it is an unorthodox chamber, glued together from glass and aluminium with Latex and can't easily be opened. I thought about the problem for a while and eventually decided to try an unorthodox solution. I connected the chamber back up again, pumped down the chamber as far as it would go, and with a big paint brush I slapped Latex milk* all over the chamber so it wetted every joint, and within minutes I could see the pressure dropping. My theory worked, the Latex was sucking it's way into the cavities and plugging up the leaks.

Three days have since passed, the Latex has dried up and the chamber is holding vacuum like never before, the leak is now in the order of 1 micron every two minutes, not bad for a system glued together with Latex and KF Viton seals which has not been baked out..

* Latex milk is a white liquid glue with a consistency similar to milk, it quickly dries to form natural latex rubber.

photo 3.JPG
Laminated Chamber

Re: FICS II Planning and construction

Posted: Wed Jan 11, 2017 12:15 am
by Steven Sesselmann
Well it's been a year since I started building this reactor and I was hoping to have some positive results to share with you guys this Christmas, but the illusive fusion dragon remains in the bottle.

It should be pretty obvious for all to see, that I like doing things the hard way, just building a standard 6" fusor isn't where I start (although I might end up there, and Richard will have a good old laugh).

I put together this video to demonstrate that it's not from lack of trying..

Wishing you all a Happy New Year with plenty of bubbles and clicks !