Tritium detection from fusor
Posted: Sun Apr 10, 2011 11:53 am
No, we haven't proved that yet, but I think we will -- or a lot of neutrons are coming out of a fusor by magic and/or it's neglecting the other reaction pathway that makes tritium instead.
Though I'm feeling the need to finish, rather than start projects these days, some are so juicy and probably so easy that....well, here we go.
Bill scored a detector for low energy betas, a Victoreen, plastic scinitllator, preamp, insanely thin Al/Mylar window -- and we've even found pinouts for it and the preamp built in.
So this suggested itself like water going downhill.
I found a "slip in" pipe cap that could be bored a little to fit the detector face, turned off the 8 sided "head" so I could chuck it the other way in the lathe and bore to fit over the detector window, and inside the detector outer shell. My big system is already plumbed to send the exhaust outdoors, via Qest/Pex plumbing (which is fantastic stuff for its intended use as well -- freezes without breaking, FYI). So this was pretty simple to make.
It fits together like this:
Now, the total gas in my fusor for a run is a pretty tiny amount -- fraction of a cc at STP (I'd have to work it out again, but I think I remember it's about .05cc or so, it's a big tank). We generally run for quite awhile without running any gas at all out of it, and due to the way turbos work, most of the gas that would come out when we pulse the exhaust valve wouldn't be hydrogen, but heavier gasses. But at the end of a run, we take it back to hard vacuum and it all comes out. I'm assuming that letting in a little fresh D during that would flush the original tank contents out, and by arranging things right, any light gas would collect in this detector by convection, which is why I show it in the orientation I do. Obviously, it will go utterly nuts during a run from X rays and neutrons (plastic scintillator), but that's not when we'll be using it anyway.
Could be fun....we will see sometime down the road, I've got to drill a hole though the shelf in the rig for this long thing to project up through as it's going to be plumbed right at the forepump output, which is just under the shelf.
Though I'm feeling the need to finish, rather than start projects these days, some are so juicy and probably so easy that....well, here we go.
Bill scored a detector for low energy betas, a Victoreen, plastic scinitllator, preamp, insanely thin Al/Mylar window -- and we've even found pinouts for it and the preamp built in.
So this suggested itself like water going downhill.
I found a "slip in" pipe cap that could be bored a little to fit the detector face, turned off the 8 sided "head" so I could chuck it the other way in the lathe and bore to fit over the detector window, and inside the detector outer shell. My big system is already plumbed to send the exhaust outdoors, via Qest/Pex plumbing (which is fantastic stuff for its intended use as well -- freezes without breaking, FYI). So this was pretty simple to make.
It fits together like this:
Now, the total gas in my fusor for a run is a pretty tiny amount -- fraction of a cc at STP (I'd have to work it out again, but I think I remember it's about .05cc or so, it's a big tank). We generally run for quite awhile without running any gas at all out of it, and due to the way turbos work, most of the gas that would come out when we pulse the exhaust valve wouldn't be hydrogen, but heavier gasses. But at the end of a run, we take it back to hard vacuum and it all comes out. I'm assuming that letting in a little fresh D during that would flush the original tank contents out, and by arranging things right, any light gas would collect in this detector by convection, which is why I show it in the orientation I do. Obviously, it will go utterly nuts during a run from X rays and neutrons (plastic scintillator), but that's not when we'll be using it anyway.
Could be fun....we will see sometime down the road, I've got to drill a hole though the shelf in the rig for this long thing to project up through as it's going to be plumbed right at the forepump output, which is just under the shelf.