Search found 10348 matches

by Richard Hull
Wed Mar 03, 2021 6:06 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Thoughts on this ebay neutron detector?
Replies: 4
Views: 80

Re: Thoughts on this ebay neutron detector?

If you have the coin, this looks like a plug and play setup.

Richard Hull
by Richard Hull
Wed Mar 03, 2021 5:58 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: One more cube fusor
Replies: 14
Views: 1162

Re: One more cube fusor

Just wow!

Richard Hull
by Richard Hull
Wed Mar 03, 2021 5:42 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Software to collect and display measured data.
Replies: 4
Views: 63

Re: Software to collect and display measured data.

I remain stunned at what the Arduino can do for so little money and such an intuitive, easy to learn, IDE. just a quick look at the capabilities and onboard, ready to use 14 or more digital and dedicated PWM pins, 2 interrupt pins and 6 - 10 bit ADCs all for about $10 in the UNO and Nano boards. The...
by Richard Hull
Tue Mar 02, 2021 7:44 am
Forum: Vacuum Technology (& FAQs)
Topic: Pirani gauge vs plasma
Replies: 3
Views: 157

Re: Pirani gauge vs plasma

John is correct. Regardless of gauge type I have always allowed for a right angle in my connection of a gauge in a device where a plasma is present. Ionized gas environments should not have a straight path into a gauge opening. What's worse, beaming into gauge tubes can really kill the tube, much le...
by Richard Hull
Mon Mar 01, 2021 5:43 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Making your own Geiger tubes - A work in progress
Replies: 0
Views: 82

Making your own Geiger tubes - A work in progress

I will start a rolling thread here on my effort to make GM tubes. As a practical point it is always much smarter to purchase NOS manufactured GM tubes for reliable operation. By the same token It is always smarter to "not' make your own fusor at home. But...who is always smart? Many of us have an in...
by Richard Hull
Mon Mar 01, 2021 5:10 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: The rhodium leap - Ouch!
Replies: 4
Views: 488

Re: The rhodium leap - Ouch!

Well, it turns out I got a deal buying my little strip of Rhodium foil at $500 was a great buy at a great moment. The current price of Rhodium is now $24,000 per troy ounce. That means if I waited that strip would now cost about $1,100. Joe was right....You only live once.

Richard Hull
by Richard Hull
Mon Mar 01, 2021 1:04 am
Forum: Vacuum Technology (& FAQs)
Topic: Help me in my baby steps in the vacuum world.
Replies: 17
Views: 1265

Re: Help me in my baby steps in the vacuum world.

Making GM detectors is a project I have been working on. I will update this effort in the radiation forum as I proceed with my effort. The upshot is that most GM detectors wind up back filled to between 50 and 100 torr with argon or neon and a quench agent. The quench agent is the sticking point. mo...
by Richard Hull
Sun Feb 28, 2021 8:31 pm
Forum: Vacuum Technology (& FAQs)
Topic: Pirani gauge vs plasma
Replies: 3
Views: 157

Re: Pirani gauge vs plasma

I could see this on the low end of the scale (10e-5) but not on the high end (10e-2). At any current over zero ma you are heating the gas. More current means more pressure. Gas pressure is sensitive to temperature and will increase as more current heats any gas at any pressure. I am not an expert on...
by Richard Hull
Sun Feb 28, 2021 8:14 pm
Forum: Vacuum Technology (& FAQs)
Topic: Bell Jar - general issue postings in future
Replies: 7
Views: 5975

Re: Bell Jar - general issue postings in future

Latest issue of the Bell jar for February is found at

http://www.belljar.net/tBJ_February_2021.pdf

Richard Hull
by Richard Hull
Sun Feb 28, 2021 5:19 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Neutron Silver Activation Demo Cell
Replies: 14
Views: 509

Re: Neutron Silver Activation Demo Cell

There is no doubt about it; when counting betas the gold standard is and always will be the 2" pancake mica windowed GM tube. I may wind up modifying my moderator imbedded GM tube from the Famos Russian SBM-20 to one of my 7311 LND 2" pancake tubes. I would have to change out my small 450 volt suppl...