Detector Crown

[Starfire]

The photos show a Neutron detector crown used in a deep dry well in a three mtr deep pond sheilded reactor experiment. The detector consists of six detector tubes and two bubble tubes. The copper pipes hold the Neutron detectors the pond provides the Neutron scatter.

[Doug Coulter]

Do you know what the motive was for using so many? Co or anti incidence kinds of things? I bet a lot of us would love to have that many N detectors to play with, but I note I saw a truck full of BF3 going up the highway yesterday -- a large tanker type truck, and there's no semi fabs near here, so someone had a use for a *lot* of it someplace. The load was a bunch of what looked like very long 2 foot diameter pipes, clearly marked as to content. No matter what form it was in, it was a lot of the stuff. Perhaps DHS has run out of all the 3He on earth already and is reverting? There is a detector outfit not so far up that road.

[Starfire]

Doug they are Russian - so many because I want to investigate coincident from isotropic - I also measured the poissor with a lead filter and got something at less than 1 micron ( I measured something which kicked the scint ) - the cross-section of lead should not stop Neutrons but there is a high magnetic field ( you'ed be suprised how big ) in my setup which may account for the small poisser and some sort of radiation.

[Doug Coulter]

John,

I didn't, but should have, realized from our other talk that was your setup, not something else (head slap, doh). May I suggest moving further talk of the detector part of this to metrology, and the details of your setup (should you find time to document them and a willingness to share) be moved to "other forms of fusion" with a back-link to this so I don't have to move this to make it coherent? (this is hard to do in this software so far on my learning curve, and risks us losing good content so I'm loath to do it if I don't have to). Once we continue in those places, we can edit a post here to link there.

I too am very interested in the sorts of things measured here -- we are having non isotropic outputs too and trying to study that, so let's put further talk about detectors into the measure place, and what you are measuring into the place for that (other forms of fusion maybe?). I have myself done some linear pinch experiments at 100's of kA that got down to a micron (maybe a little less) for X ray source sizes. If that were making neutrons instead of X rays (we used tungsten plasmas for our work then) yes -- it would be interesting indeed to see the pattern of output, especially vs time on a pretty fast scaling like the DPF guys are working with -- it matters about "when" things happen to really understand the process - in order to improve it.

I've not yet had time to put the details of that experiment up here, but I do plan to -- it worked really well and wasn't really hard to do. One could easily make it happen in D instead of W I think, but haven't yet. Inertia -- I have 18kj worth of maxwell caps just sitting. (120 uf x 10kv x 3 of them -- 18nh ea series L and vanishing R, rated for 100ka each shots at long life). But my other work is also going so well I don't want to go for that way just now myself -- but have also been getting ready to -- just in case. I am listening and want to be informed.