Search found 179 matches

by Liam David
Sun Mar 14, 2021 2:07 am
Forum: Images du Jour
Topic: Fusor Update - Liam David
Replies: 39
Views: 6683

Re: Fusor Update - Liam David

Maximum neutron rate is now 2e6 at 50kV, 8.56mA, though excessive sparking prevented me from maintaining the output. When I lower the current, however, I can push the voltage much higher. At 59kV, 0.86mA, it produced 4.1e5n/s, which gives a Q value of 9.2e-9. The theoretical output at 59kV, 8.56mA i...
by Liam David
Wed Mar 03, 2021 7:04 pm
Forum: Announcements and Site Administration Topics
Topic: Newly published fusor paper
Replies: 7
Views: 907

Re: Newly published fusor paper

I have access to the paper through my university and could distribute it on a limited basis. PM if interested. They've also done some radiography with dysprosium activation.
by Liam David
Wed Mar 03, 2021 1:05 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Thoughts on this ebay neutron detector?
Replies: 7
Views: 696

Re: Thoughts on this ebay neutron detector?

I haven't purchased any electronics from Maximus Energy but have bought two different neutron detector tubes from him. The 10,000CPS is based on the shaping time of the amplifier and the sample rate of the ADC, which he lists as being 5MHz. This is more than enough for that count rate, although I do...
by Liam David
Wed Mar 03, 2021 12:51 am
Forum: Control and Instrumentation Hardware and Software
Topic: Software to collect and display measured data.
Replies: 16
Views: 1358

Re: Software to collect and display measured data.

I use Matlab to connect to an Arduino via ethernet and save/display data in realtime. The master Arduino drives some ADS1115, 16 bit ADCs and communicates with two other Arduinos that act as scalars for my neutron counters. I have Matlab requesting samples at a rate of 10/s, though with some streaml...
by Liam David
Sat Feb 27, 2021 10:02 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Another (Preliminary) Report on Anisotropy
Replies: 13
Views: 1304

Re: Another (Preliminary) Report on Anisotropy

I now have some pretty good data on neutron anisotropy in the fusor "equatorial plane." Each run was ~5 minutes long at ~35kV, 8.56mA, 6-7e5n/s. The small 1.5" detector was 43cm from the center of the chamber and the output was monitored by my larger tube on the opposite side of the fusor. Count rat...
by Liam David
Fri Feb 26, 2021 3:03 am
Forum: Images du Jour
Topic: Fusor Update - Liam David
Replies: 39
Views: 6683

Re: Fusor Update - Liam David

Thanks, everyone, for the compliments. Been spending as much time on fusion as I do on school recently... I found the actual source of the arcing and instabilities, which was only exacerbated by the offset grid. In moving the feedthrough quartz up and down, both for positioning in the chamber and se...
by Liam David
Thu Feb 25, 2021 12:03 am
Forum: Images du Jour
Topic: Fusor Update - Liam David
Replies: 39
Views: 6683

Re: Fusor Update - Liam David

Arrived today, will be machined likely next week: PXL_20210224_221335526.jpg Both the chamber and endcaps will be fully water-cooled, and I have a few modifications that should help the field symmetry. I'm looking to push past 60kV, and with how I've arranged the water cooling, the angular neutron d...
by Liam David
Tue Feb 23, 2021 3:37 am
Forum: Images du Jour
Topic: Fusor Update - Liam David
Replies: 39
Views: 6683

Re: Fusor Update - Liam David

I haven't had any arcing, just the occasional sparking thanks to my grid shifting off-center. The spots on the side are from secondary beams that form once the voltage gets high enough, something like 5kV.

PXL_20210119_225912812.jpg
Deliberately off-axis, secondary beam downward
by Liam David
Mon Feb 22, 2021 11:46 pm
Forum: Images du Jour
Topic: Fusor Update - Liam David
Replies: 39
Views: 6683

Re: Fusor Update - Liam David

I found what was limiting me to 35kV. The centering washer slipped and let the grid become misaligned. Moreover, I think I overtightened the grid stalk, which cracked the ceramic shielding washer when everything got hot. I just got some more washers in and will be back in business soon. The colorful...
by Liam David
Fri Feb 19, 2021 11:26 pm
Forum: Images du Jour
Topic: Fusor Update - Liam David
Replies: 39
Views: 6683

Re: Fusor Update - Liam David

I activated some silver sheet today (2x6x0.010"). Max CPM on a 2" pancake ~3s after shutoff was 2500. Estimated "TIER" on the highest run was 7e5n/s, with arcing limiting operation to 30-35kV. Activation lasted between 3 and 10 minutes, with the longest run corresponding to the highest TIER. The neu...