Want Some Big He-3 Reuter Stokes Proportional Tubes?

This area is for discussions involving any fusion related radiation metrology issues. Neutrons are the key signature of fusion, but other radiations are of interest to the amateur fusioneer as well.
Post Reply
hjerald1
Posts: 54
Joined: Mon Feb 25, 2008 11:28 am
Real name:

Want Some Big He-3 Reuter Stokes Proportional Tubes?

Post by hjerald1 »

A mere $6K each........He-3 shortage and all.......
supply and demand in action .

Saw a similar one earlier.....$5500 bid did not meet reserve.


http://cgi.ebay.com/Neutron-Detectors-V ... 27b0ff6659

Jerry
User avatar
Carl Willis
Posts: 2841
Joined: Thu Jul 26, 2001 7:33 pm
Real name: Carl Willis
Location: Albuquerque, New Mexico, USA
Contact:

Re: Want Some Big He-3 Reuter Stokes Proportional Tubes?

Post by Carl Willis »

They asked me to come up to Espanola and test these units with a neutron source and prepare a little report a few months back. So I can vouch for their proper operation. I also know that the asking price is based on several offers they have already received for the tubes alone.

Take-home message: hang onto your He-3 tubes. They are a valuable investment.

-Carl
Carl Willis
http://carlwillis.wordpress.com/
TEL: +1-505-412-3277
User avatar
Richard Hull
Moderator
Posts: 14991
Joined: Fri Jun 15, 2001 9:44 am
Real name: Richard Hull

Re: Want Some Big He-3 Reuter Stokes Proportional Tubes?

Post by Richard Hull »

So, the huge, (for a hamfest), $200.00 price I paid for the 24" brand new P4 GE/Reuter and Stokes at the Vienna, VA Hamfest a few weeks back was a good deal.......

Like Carl says, hang on to yer' 3He tubes for dear life.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Dustinit
Posts: 257
Joined: Tue Mar 18, 2008 8:02 pm
Real name:

Re: Want Some Big He-3 Reuter Stokes Proportional Tubes?

Post by Dustinit »

Looks like a good investment if you have one.

http://www.newscientist.com/article/dn1 ... e-dry.html

Dustin
User avatar
Richard Hull
Moderator
Posts: 14991
Joined: Fri Jun 15, 2001 9:44 am
Real name: Richard Hull

Re: Want Some Big He-3 Reuter Stokes Proportional Tubes?

Post by Richard Hull »

I love the part of the article where Pacfic Northwest labs is working on new neutron detector tubes that use boron tri-fluoride or even boron lined tubes. What is old is now new again. Wonder of wonders. I new they would find a clever work-around....Such sheer genius. Why didn't someone think of these novel new tubes 60 or 70 years ago?

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
DaveC
Posts: 2346
Joined: Sat Jun 30, 2001 1:13 am
Real name:

Re: Want Some Big He-3 Reuter Stokes Proportional Tubes?

Post by DaveC »

Another apparently sterling example of public tax dollars hard at work, eh?

But I rather suspect they mean to revisit the older techniques and see if they can be improved. But of course, we all knew that ....


Dave Cooper
User avatar
Carl Willis
Posts: 2841
Joined: Thu Jul 26, 2001 7:33 pm
Real name: Carl Willis
Location: Albuquerque, New Mexico, USA
Contact:

Re: Want Some Big He-3 Reuter Stokes Proportional Tubes?

Post by Carl Willis »

A much better BF3 tube could be made just by filling to pressures above 1 Atm. Almost everything commercially available now has 1 Atm or less, in order to comply with DOT toxic-gas HAZMAT restrictions. He-3 tubes routinely have several Atm or more. BF3 tubes even have a few nuclear advantages, including a better neutron-to-gamma pulse height ratio. It's a shame to see He-3 become so precious, but there's nothing really magic about it.

-Carl
Carl Willis
http://carlwillis.wordpress.com/
TEL: +1-505-412-3277
Chris Seyfert
Posts: 37
Joined: Sun Mar 29, 2009 2:51 am
Real name:

Re: Want Some Big He-3 Reuter Stokes Proportional Tubes?

Post by Chris Seyfert »

I don't think it's just a DOT restriction. I was also wondering why manufacturers didn't pressurize BF3 tubes higher than 1 atm, until I stumbled across this nugget in Glenn Knoll (3rd ed):

"Because the performance of BF3 as a proportional gas is poor when operated at higher pressures, its absolute pressure in typical tubes is limited to about 0.5 - 1.0 atm."

I'd hazard a guess that BF3 is somewhat electronegative, and starts acting to self-quench at higher pressures, like sulfur hex would.
User avatar
Richard Hull
Moderator
Posts: 14991
Joined: Fri Jun 15, 2001 9:44 am
Real name: Richard Hull

Re: Want Some Big He-3 Reuter Stokes Proportional Tubes?

Post by Richard Hull »

There are probably many ways to skin this cat. Generally, in technology, where there is a will, there is a way........Especially if there is a payday at the end of the process.

The neutron measurement situation is not dire; it is just thrown into some disarray as the applecart of normal operational flow has been upset. BF3s and B lined tubes will just make a comeback using tighter and more modern and clever electronics than that used during their heyday. BF3 tubes never really went away or saw the drop in use that boron lined tubes did. All had and still have applications based on flux levels where they are to be applied.

A lot of experimental, low flux operations saw immediate relief once the efficient, pressurized 3He tubes came into being, pulling older methods' results out of the experimental noise floor. Thus the rush to the 3He, especially for detecting small or shielded amounts of hiden or lost nuclear materials. This was magnified 100X after 9-11 while the production of 3He was stagnant or reduced.

In the short term, especially in the surplus sense, this current situation with 3He will have an effect on newbie and upgrading adepts among us. It is just amazing it all happened so fast.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
User avatar
Carl Willis
Posts: 2841
Joined: Thu Jul 26, 2001 7:33 pm
Real name: Carl Willis
Location: Albuquerque, New Mexico, USA
Contact:

Re: Want Some Big He-3 Reuter Stokes Proportional Tubes?

Post by Carl Willis »

As usual, Glenn Knoll is pretty much the last word on detectors. So maybe there's little hope for a better high-pressure BF3 after all. Good catch, Chris.
Carl Willis
http://carlwillis.wordpress.com/
TEL: +1-505-412-3277
Post Reply

Return to “Neutrons, Radiation, and Detection (& FAQs)”