Search found 132 matches

by Liam David
Sun Sep 08, 2019 3:03 pm
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - Neutron Transport Simulation, Detector Calibration, and Shielding
Replies: 10
Views: 2612

Re: FAQ - Neutron Transport Simulation, Detector Calibration, and Shielding

Richard, I cannot create a post in the FAQ sections. The button is not there. If I could I would have done so.
by Liam David
Sat Sep 07, 2019 8:20 pm
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - Neutron Transport Simulation, Detector Calibration, and Shielding
Replies: 10
Views: 2612

Re: FAQ - Neutron Transport Simulation, Detector Calibration, and Shielding

Alex, you are absolutely correct in the thermal peak being around 9-10cm. My mistake in reading the graph. If I had editing rights it would be fixed. I did attempt to follow the latest instructions regarding the cross-section data but for reasons unknown the commands failed. In step 4 I did include ...
by Liam David
Sat Aug 31, 2019 11:42 pm
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - Neutron Transport Simulation, Detector Calibration, and Shielding
Replies: 10
Views: 2612

Re: FAQ - Neutron Transport Simulation, Detector Calibration, and Shielding

Cosmic neutrons are indeed a "does my detector work?" discriminator, though with the high variability due to probability (~sqrtN), altitude, latitude, the sun doing it's stuff, I doubt it's more useful than that. You'd need a minimum of several hours of data collection, and even then, I doubt you'd ...
by Liam David
Sat Aug 03, 2019 1:05 am
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - Neutron Transport Simulation, Detector Calibration, and Shielding
Replies: 10
Views: 2612

FAQ - Neutron Transport Simulation, Detector Calibration, and Shielding

This FAQ (should it be raised to that status) will discuss neutron transport simulations and their applicability to fusors. This lengthy block of text is not a beginner's FAQ, so one should be well-versed in all topics in the Neutrons and Detection FAQs before continuing. While this is not a "freque...
by Liam David
Wed Jul 31, 2019 11:09 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Joe Gayo's lab tour
Replies: 69
Views: 18405

Re: Joe Gayo's lab tour

Having my enthusiasm for detecting tritium crushed in the post (http://www.fusor.net/board/viewtopic.php?f=50&t=12900) Robert mentioned, I think I can safely say that strange light-atom combinations are producing the false positives. About a week ago I measured the partial pressure of m/z = 6 to be ...
by Liam David
Mon Jul 22, 2019 11:25 pm
Forum: Images du Jour
Topic: I'm back, and fusing
Replies: 5
Views: 2524

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: 2524

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: 2321

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: 1805

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: 1805

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...