Fusor Forums

The precipitator supply has a current limiter circuit so the 68k ballast resistor may not be necessary.

Mark Rowley

Hello,

I would like to update you about my fusor project. I stoped to work on the fusor for a while, because I needed to focus in my studies. But now, here I am again.

Today we tested some parts of the system. We have put the system under low pressure (1x10-5 torr),and we have made some plasma (around 15 minutes and average 30 mtorr, 10.000 volts and 2mA).

Our next steps are:
-Test more the electric part;
-Make the lead protection;
-Connect the deuterium.

I am posting again some photos of my fusor and and of some new parts that we bought.

Pressure Control
General
Ballast and Voltage Divisor
High Voltage Power Supply
Control voltage amper ans pressure
Fore Pump
Turbo Pump
Grid
General View

Looking good!
Just a suggestion, pot the precip supply in oil and add more insulation to the HV feedthru. If you don’t want to make an oil socket for the feedthru, at the very least add some flashover protection and HV putty like Richard had suggested in other posts. It’s worked great for his system. Trust me, it’ll save you a ton of headache in the long run.

Mark Rowley.

Hello,

This is a video of plasma ignition using the high voltage power supply.

https://youtu.be/4UPfHryG9vw

Just another thought after seeing the video... your grid design may limit ion recirculation to the openings of your “coiled tube“ grid design. Spherical or 360 degree recirculation patterns are probably best as they offer more pathways for D+D collisions/fusions.

Mark Rowley

Hello Mr. Rowley,

Thank you very much for your suggestions. I will work on flashover protection.

About the grid, this shape was easier for me to build, we used stainless steel wires and I couldn't make a good spherical grid. I will try again and see if I can get a different shape.

Regards,

Eduardo

Hey,
Just an idea so you make your grid as Mark said
Take a look at this approach viewtopic.php?f=6&t=2484

Eduardo,
Scott Moroch made these excellent simulation videos which depict ion recirculation patterns. The first two videos show the efficiency of the classic spherical grid design. The third video gives an idea of the limitations with your axial grid design.

Spherical 1
https://www.youtube.com/watch?v=KhYKnPy1pz0

Spherical 2
https://youtu.be/JjcX1yIQllA

Axial 1
https://www.youtube.com/watch?v=P5lp3Wu_EkU

Mark Rowley

Hello,

These are the results of 19 october tests:

Time (minutes after plasma ignition)--Pressure (militorr)--Volts (V)--Ampers (mA)
2:10--10--8700--0.2
3:00--8--9000--0.1
4:20--9--8500--0.3
5:00--8--12000--0.4
6:00--7--13000--0.2
7:00--16--6500--3.1
8:00--14--9000--3.8
9:00--12--10000--3.1
10:30--10--13000--2.3
12:00--9--16000--1.5

And two youtube videos. Sorry, but they are in Portuguese.

https://youtu.be/ezo6oZoqhh8

https://youtu.be/ZYjFilj12SY

For a 2.75" system using a 30kV precipitator supply, those numbers seem about right for an air plasma. When you switch over to deuterium all those numbers will change.

Mark Rowley

Mark is correct and you are doing this correctly. With a great demo system that you have you are gaining valuable "operational experience" and I am glad you are doing it with air. In the beginning, back in October of 1997, I spent 1 full year with fusor I and fusor II. I read books on ionized gases, vacuum systems and fusion during this time as well. When it came time to do fusion I was 100% prepared, although there was still a small learning curve as I did fusion in Feb. 1999. I had no real group to look to for help as there was no fusor.net. I was on my own. I first did fusion in Fusor III. I stayed with the lower performing fusor III for 3.5 years as I worked hard on neutron detection systems and went through 3 different detection schemes and used up my first small 25liter bottle of deuterium due to not having a secondary diffusion or turbo pump. I learned after fusor II that any real fusor system is doomed to be a large sprawl of many interconnected pieces of gear and gave up on the idea of a closed box containing a real fusor system.

Keep up the advancing effort which, thus far, is exemplary.

I attach images of all of those 3 early systems spanning 5 years before the advent of Fusor IV. Each image is labeled and explained.

Richard Hull