Search found 157 matches

by Liam David
Mon Jul 22, 2019 11:25 pm
Forum: Images du Jour
Topic: I'm back, and fusing
Replies: 5
Views: 5001

Re: I'm back, and fusing

FBM printing leaves too many irregularities and any hope of preventing breakdown would require 100% fill. That would really take some time to print. I suspect that SLA would work better, but I don't know about the dielectric strength of the resin. ABS is pretty bad at ~500V/mil, but that's likely mu...
by Liam David
Thu Jul 18, 2019 1:53 am
Forum: Images du Jour
Topic: I'm back, and fusing
Replies: 5
Views: 5001

Re: I'm back, and fusing

Funny you should ask that. I 3D printed a connector out of ABS a couple years ago but once I pushed ~35kV there were arcing issues. It finally bit the dust just a couple days ago and left a carbonized trace. The socket cannot be run to any appreciable voltage unless there's a proper connector instal...
by Liam David
Mon Jul 15, 2019 10:49 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Transparent Ceramic Viewports
Replies: 8
Views: 5101

Re: Transparent Ceramic Viewports

This is not to shoot down your idea to use exotic (and likely expensive) materials, but regarding ion beam viewport damage there are simpler solutions. First, just don't orient the grid such that gaps are inline with glass or ceramic. It's localized heating and large spacial and temporal thermal gra...
by Liam David
Mon Jul 15, 2019 2:37 pm
Forum: Images du Jour
Topic: Ion Beams Destroying Viewports
Replies: 5
Views: 4059

Re: Ion Beams Destroying Viewports

The turbo's fine as it was at 66% speed and the inrush was only to ~10 torr. I isolated it immediately after noticing the problem and didn't know whether the viewport would still implode. The viewport has since been replaced with a blank and I have again done fusion, but I added some magnets on the ...
by Liam David
Sat Jul 13, 2019 11:59 pm
Forum: Images du Jour
Topic: Ion Beams Destroying Viewports
Replies: 5
Views: 4059

Ion Beams Destroying Viewports

This is yet another demonstration of why fusor chambers should not be made of glass or other brittle materials. It may also serve as a warning for those building small chambers based on 2.75" conflat systems. I have a 2.75" conflat 6-way chamber with two viewports, one on axis with a graphite and tu...
by Liam David
Sat Jul 06, 2019 4:33 pm
Forum: Images du Jour
Topic: I'm back, and fusing
Replies: 5
Views: 5001

I'm back, and fusing

It's been a few years since I posted in these forums, though recent progress on my fusor and a free summer have demanded I return. I have likely been grouped with the scores of youngsters who arrive here excited but fade away having failed to achieve fusion or lost interest. I want to remove myself ...
by Liam David
Wed Jan 04, 2017 1:44 am
Forum: Images du Jour
Topic: First Fusion for Liam David - Neutron Club Application
Replies: 14
Views: 7506

Re: First Fusion for Liam David - Neutron Club Application

I have a 2.75" butterfly valve between the turbo and chamber and I always throttle the pump before introducing deuterium. It does wonders for gas usage. Dennis, what is the Cv for the needle valve you're using? I use one with a 0.05Cv (I think the rating is for water, but I'm not too sure), which wo...
by Liam David
Tue Dec 27, 2016 5:05 am
Forum: Images du Jour
Topic: First Fusion for Liam David - Neutron Club Application
Replies: 14
Views: 7506

Re: First Fusion for Liam David - Neutron Club Application

I have the Spellman supply, chamber, and cart all grounded to a central port and then a grounding rod stuck eight feet in the dirt outside. Based on some more testing I did today, I believe that the counts I received yesterday were electrical noise. I will have to do a lot more testing and improve t...
by Liam David
Mon Dec 26, 2016 10:33 pm
Forum: Images du Jour
Topic: First Fusion for Liam David - Neutron Club Application
Replies: 14
Views: 7506

Re: First Fusion for Liam David - Neutron Club Application

I did not have a ballast resistor in the first runs, but I will use a 60k resistor in my next attempt. Kinda sorta forgot it.... I am almost done with a mains frequency 50kV x-ray supply which will allow me to push the fusor to the limits without having an electronic unit shut off on me, so I'll pro...
by Liam David
Mon Dec 26, 2016 12:35 am
Forum: Images du Jour
Topic: First Fusion for Liam David - Neutron Club Application
Replies: 14
Views: 7506

First Fusion for Liam David - Neutron Club Application

Today, December 25, 2016, I ran my fusor with deuterium for the first time and I believe that I have achieved fusion. I have documented my progress semi-regularly on the forums for the past few years, mostly in the images du jour section, but I'll give an overview of my system before I discuss the r...