Search found 124 matches

by AllenWallace
Tue Feb 22, 2005 5:32 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Run, don't walk and go buy a big He3 Detector!
Replies: 6
Views: 2855

Re: Run, don't walk and go buy a big He3 Detector!

<t>>Thirty [counts per minute] sounds high to me.<br/> Not really. A google search shows that the background neutron flux increases with elevation:<br/> <br/> Sea Level = 1X<br/> 2000 ft = 2X<br/> 4500 ft = 3X<br/> 40K ft = 100X<br/> <br/> Robert Hull indicates he is getting about 15 CPM background ...
by AllenWallace
Mon Feb 21, 2005 1:45 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Run, don't walk and go buy a big He3 Detector!
Replies: 6
Views: 2855

Re: Run, don't walk and go buy a big He3 Detector!

Frank,
What is your background rate? Also, what is your elevation?
My 22" He3 tube has a background rate of about 30 cpm, and I'm at 4700 feet.
Allen Wallace
by AllenWallace
Wed Feb 16, 2005 4:11 am
Forum: FAQs: Fusor Construction & Operation
Topic: FAQ: Heavy Water Electrolysis Deuterium Source
Replies: 32
Views: 22676

Re: Heavy Water Electrolysis Deuterium Source

Andrew,

How do you regulate the D2 volume? It seems to me that if you suck too much D2 into the fusor, you will suck the D20 into the drieite.

Allen Wallace
by AllenWallace
Mon Feb 14, 2005 3:51 am
Forum: Vacuum Technology (& FAQs)
Topic: Pfeiffer Balzers TCP 120 Schmatics ??
Replies: 4
Views: 2919

Re: Pfeiffer Balzers TCP 120 Schmatics ??

I have a poor quality schematic of the TCP120. I'll start scanning it in. Meanwhile, if anyone has a better copy, I've love have something which is more readable!
by AllenWallace
Tue Jan 04, 2005 4:38 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: What is the best preamp for a He3 tube
Replies: 9
Views: 3165

Re: What is the best preamp for a He3 tube

<t>Your tube voltage is "up to 5 KV" ? What pressure is the tube? <br/> <br/> I have two tubes, one rated at 1800 VDC (with an intregrated power supply-preamp-SCA) and the other tube is rated at 3750 volts and is a time-of-flight device. Your high voltage makes me suspect your tube might be a TOF de...
by AllenWallace
Thu Dec 23, 2004 6:38 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: World's simplest geiger counter
Replies: 4
Views: 2887

World's simplest geiger counter

<t>This is the ‘world’s simplest’ Geiger counter. I have built this in a small plastic enclosure and it works well. As you press the push button switch, the transformer is magnetically saturated. When you open the push button switch, the magnetic energy is converted into electrical energy and a high...
by AllenWallace
Wed Dec 08, 2004 3:41 am
Forum: Interesting Links
Topic: Ludlums manuals, schematics, etc
Replies: 2
Views: 2557

Ludlums manuals, schematics, etc

http://www.ludlums.com/techinfo.htm

This site has many geiger counter, scintillator and neutron detector manuals, most with schematics.
by AllenWallace
Sat Dec 04, 2004 3:43 am
Forum: Fusor and/or General Fusion Theory (& FAQs)
Topic: pulsed fusor - what duty cycle?
Replies: 4
Views: 2130

pulsed fusor - what duty cycle?

<t>It seems to me that low duty cycle power power supplies are easy (cheap) to build. Slowly charge up a capacator and then dump it into the fusor.<br/> <br/> Can anyone offer any theory on how fast fusor occurs? What is the minium pulse width? 1 ps? 1ns? 1ms? 1/60 s?<br/> <br/> How long does it tak...
by AllenWallace
Sat Dec 04, 2004 3:17 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: FlybacK Transformers
Replies: 14
Views: 5540

Re: FlybacK Transformers

<t>One serious problem with modern flybacks is that the diodes are build into the device, which generates positive high voltage. <br/> <br/> Fusors require negitive high voltage.<br/> <br/> I've tried reversing the polarity by grounding the positive lead and picking the negitive from the bottom pins...
by AllenWallace
Thu Jul 08, 2004 1:13 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Deuterium Gas - current costs- status
Replies: 4
Views: 3340

Re: Deuterium Gas - current costs- status

<t>I think I bought 20g of D20 for about $30.00. If you had a perfect conversion from D20 to D2, I think this would yield about 10 Liters of D2. If we perfected the conversion, even with loosing half of the deturium, it would still be a very small fraction of the cost of a D2 bottle. I would encorag...