Search found 111 matches

by Joe Gayo
Wed Jan 16, 2019 4:44 am
Forum: Images du Jour
Topic: Joe Gayo's Fusor - Neutron Detection Upgrade
Replies: 29
Views: 8739

Joe Gayo's Fusor - Neutron Detection Upgrade

Upgraded detection to BF3 tube with TC174 preamp
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Clean detection pulse with shaping
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90n/sec @ 27mTorr, 43kV, and 10mA
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by Joe Gayo
Wed Jan 16, 2019 3:22 am
Forum: Images du Jour
Topic: Joe Gayo's Fusor
Replies: 20
Views: 6124

Re: Joe Gayo's Fusor

I think it's x-ray detection not noise.
by Joe Gayo
Tue Jan 15, 2019 3:54 am
Forum: Images du Jour
Topic: Joe Gayo's Fusor
Replies: 20
Views: 6124

Re: Joe Gayo's Fusor

Based on looking at the pulse waveform from the amplifier with an oscilloscope I was able to setup a window discriminator (2.1-5.9V) to reject the majority of events that occur without a moderator. It does appear that most non-moderator events have a leading negative voltage spike and a subsequent >...
by Joe Gayo
Mon Jan 14, 2019 6:08 pm
Forum: Images du Jour
Topic: Joe Gayo's Fusor
Replies: 20
Views: 6124

Re: Joe Gayo's Fusor

I've done this test before but I re-ran this morning (detector in same relative position to fusor for all tests, 10cm) - 30 minute background with moderator: 24 counts No moderator / No activation oven (within 3m): 28 mTorr D2 35kV @ 10mA 90 seconds, 274 counts (note: pulse has leading negative comp...
by Joe Gayo
Mon Jan 14, 2019 6:31 am
Forum: Images du Jour
Topic: Joe Gayo's Fusor
Replies: 20
Views: 6124

Re: Joe Gayo's Fusor

I think we said the same thing ... with and without the moderator ...

I was proposing an additional test without Deuterium but thinking about it, that isn’t valuable

And if you are a forum moderator for 18 years, you will probably repeat yourself a lot
by Joe Gayo
Mon Jan 14, 2019 5:12 am
Forum: Images du Jour
Topic: Joe Gayo's Fusor
Replies: 20
Views: 6124

Re: Joe Gayo's Fusor

Richard,

I assume you are talking about tests with and without the moderator, then with and without deuterium in order to eliminate x-rays and electronic noise respectively.
by Joe Gayo
Mon Jan 14, 2019 3:39 am
Forum: Images du Jour
Topic: Joe Gayo's Fusor
Replies: 20
Views: 6124

Re: Joe Gayo's Fusor

I would rather wait until my setup is calibrated. I have a high degree of confidence that neutrons are being generated but an exact quantity (+/-20%) is more satisfying. In addition, I’m improving the signal processing of the neutron pulse in the meantime.
by Joe Gayo
Mon Jan 14, 2019 2:10 am
Forum: Images du Jour
Topic: Joe Gayo's Fusor
Replies: 20
Views: 6124

Re: Joe Gayo's Fusor

Thanks.

4-6 weeks will be a long wait for the bubble dosimeter, but worth it.
by Joe Gayo
Sun Jan 13, 2019 7:13 pm
Forum: Images du Jour
Topic: Joe Gayo's Fusor
Replies: 20
Views: 6124

Re: Joe Gayo's Fusor

CHM-11 Tube Adapter Box

HV Input w/ RC Filter (2Meg * 47nF)

Bias w/ 50Meg

AC Couple w/ 33pF
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by Joe Gayo
Sun Jan 13, 2019 7:07 pm
Forum: Images du Jour
Topic: Joe Gayo's Fusor
Replies: 20
Views: 6124

Joe Gayo's Fusor

Pressure: 25mTorr (4mTorr base)
Voltage: 40kV (50kohm ballast resistor)
Current: 6mA

Detector: CHM-11 (1600V, 64x Gain, 3V Threshold)
Run CPM: 622 (Avg 5 min run)
Background CPM: 2 (Avg 30 min)
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