Search found 116 matches

by Joe Gayo
Mon Jul 22, 2019 3:23 pm
Forum: Images du Jour
Topic: Neutron Club Application - Mark Rowley
Replies: 6
Views: 3503

Re: Neutron Club Application - Mark Rowley

@Mark - Just for completeness, you are running the SNM-14 tube (http://www.sovtube.com/x-ray-and-geiger-tubes/601-snm-14.html) below the corona region which does remove the corona noise but may present a gamma rejection problem at higher voltages. This seems to recommend 900-1000V - https://inis.iae...
by Joe Gayo
Tue Jul 02, 2019 1:23 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Joe Gayo's lab tour
Replies: 69
Views: 29250

Re: Joe Gayo's lab tour

Yes, but I want a lot more data. I’ve had some runs where the rates were much higher but unfortunately I didn’t have a bubble dosimeter present.

I’ve activated silver, indium, and manganese quite easily to many times background. The device can run at 5E+6 for extended periods (60 minutes).
by Joe Gayo
Tue Jul 02, 2019 1:07 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Joe Gayo's lab tour
Replies: 69
Views: 29250

Re: Joe Gayo's lab tour

I have a bubble dosimeter reading of 4.8E+7 which seems ridiculous...

@Robert
I have Knoll’s book and agree it’s a must. There are several things I’m going to investigate with the counting electronics (plus add the greater distance detector)
by Joe Gayo
Tue Jul 02, 2019 12:22 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Joe Gayo's lab tour
Replies: 69
Views: 29250

Re: Joe Gayo's lab tour

Yes, I’m going to set up an additional detector at a greater distance (The present detector location is calibrated and gives nice resolution for low current/voltage operating conditions), but I was curious about typical resolving time for a BF3 detector system. I could setup a signal generator to te...
by Joe Gayo
Mon Jul 01, 2019 7:23 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Joe Gayo's lab tour
Replies: 69
Views: 29250

Re: Joe Gayo's lab tour

@Lukas - If you are talking about the small oscillations that follow a trendline, then this is a result of the statistical nature of neutron measurement. The counts are averaged over 500 msec but I only report rates that have been averaged over 5 seconds or more and not a single measurement spike. @...
by Joe Gayo
Mon Jul 01, 2019 1:14 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Joe Gayo's lab tour
Replies: 69
Views: 29250

Re: Joe Gayo's lab tour

My -100kV @ 20mA power supply arrived on Friday ... Several Observations - - The chamber can support 90kV (so far ... more conditioning may improve) - I measure about 2E+6 n/sec/mA at 90kV ... multiple 3.6E+7 runs (90kV, 18mA, 19 mTorr) - Need to reposition detectors as not to saturate (110 bub in 6...
by Joe Gayo
Thu Jun 27, 2019 4:58 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Joe Gayo's lab tour
Replies: 69
Views: 29250

Re: Joe Gayo's lab tour

I'm still collecting data (the chamber is still improving with loading and vacuum quality), but here are some general results: 60 kV, ~1M n/sec/mA (16.2M at 15mA, Q = 2.11 e-8!), 25 mTorr I created this video to record results at 5mA (40 - 60kV), 22mTorr. https://youtu.be/1MLFN8FKvZc Performance @ 2...
by Joe Gayo
Mon Jun 24, 2019 10:21 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Joe Gayo's lab tour
Replies: 69
Views: 29250

Re: Joe Gayo's lab tour

@Jon - Thank you for the kind words and the tour of your impressive lab! @Everyone - I have a -100kV @ 20mA power supply arriving in the next few weeks and will begin experimenting with different cathode/anode materials. Based on some preliminary results the Aluminum construction may be contributing...
by Joe Gayo
Fri Jun 21, 2019 4:27 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Joe Gayo's lab tour
Replies: 69
Views: 29250

Re: Joe Gayo's lab tour

@Dan Sure it does ... it's an axially symmetric (RZ) code/solver. I actually, know the individual that wrote Starfish (his Ph.D.) and he and I are working together on simulations.
by Joe Gayo
Wed Jun 19, 2019 6:02 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Joe Gayo's lab tour
Replies: 69
Views: 29250

Re: Joe Gayo's lab tour

@Rex Yes, in this simulation the applied potential difference is 50kV. You are correct about the symmetry of the simulation as well. The animation represents microseconds. The software is Starfish (https://www.particleincell.com/starfish/ - Free!) @Carl Thanks! The electrode geometry is discussed in...