My progress II

For posts specifically relating to fusor design, construction, and operation.
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Mark Rowley
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Re: My progress II

Post by Mark Rowley » Sat Sep 14, 2019 6:07 pm

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

Mark Rowley

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Eduardo_Machado
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Re: My progress II

Post by Eduardo_Machado » Sun Oct 13, 2019 9:08 pm

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
WhatsApp Image 2019-10-13 at 17.27.38(8).jpeg
pressure control
General
WhatsApp Image 2019-10-13 at 17.27.38(6).jpeg
general
Ballast and Voltage Divisor
WhatsApp Image 2019-10-13 at 17.27.38(7).jpeg
ballast and voltage divisor
High Voltage Power Supply
WhatsApp Image 2019-10-13 at 17.27.38(4).jpeg
high voltage power supply
Control voltage amper ans pressure
WhatsApp Image 2019-10-13 at 17.27.38(3).jpeg
controls voltage amper and pressure
Fore Pump
WhatsApp Image 2019-10-13 at 17.27.38.jpeg
fore pump
Turbo Pump
WhatsApp Image 2019-10-13 at 17.27.38(1).jpeg
turbo pump
Grid
WhatsApp Image 2019-10-13 at 17.27.38(5).jpeg
grid
General View
WhatsApp Image 2019-10-13 at 17.27.38(2).jpeg
general view

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Mark Rowley
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Re: My progress II

Post by Mark Rowley » Sun Oct 13, 2019 10:21 pm

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.

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Eduardo_Machado
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Re: My progress II

Post by Eduardo_Machado » Sun Oct 13, 2019 10:33 pm

Hello,

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

https://youtu.be/4UPfHryG9vw

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Mark Rowley
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Re: My progress II

Post by Mark Rowley » Sun Oct 13, 2019 11:28 pm

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

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Eduardo_Machado
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Re: My progress II

Post by Eduardo_Machado » Sun Oct 13, 2019 11:38 pm

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

Pablo Llaguno
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Re: My progress II

Post by Pablo Llaguno » Fri Oct 18, 2019 4:42 am

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

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Mark Rowley
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Re: My progress II

Post by Mark Rowley » Sat Oct 19, 2019 5:30 pm

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

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Eduardo_Machado
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Re: My progress II

Post by Eduardo_Machado » Sun Oct 20, 2019 11:37 pm

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

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Mark Rowley
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Re: My progress II

Post by Mark Rowley » Mon Oct 21, 2019 4:59 am

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

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