[NewCandle] further adventures of pixie 23

[Nick Reiter]

Hi Keith and all,

Yesterday, I decided to begin pulling down and sequestering the different components of the pixie bucket system.

I pulled the foil rolls and set them on a draining and drying towel.  Following this, I made a thorough survey of the liquid in the bucket from all positions, particulary to see if there was indeed U residue settling out as an oxide at the bottom.

This didn't seem to be the case - there was no difference in readings from any direction for a given spacing, plastic intervening or no.  The liquid in the bucket at a couple of cm spacing was a decent isotropic 200 to 300cpm.

I allowed the rolls to dry out overnight.  This morning, I looked at a few (there are six for a pixie bucket).  Now keep in mind that the one end of a roll is sawed off, and thus the turns are crushed and "swaged" over from the saw blade.  So effectively, there is an open end and a sort-of closed end to each roll.

At 1cm spacing from any position at the roll OD side, I saw 2000 to 3000cpm.  At the sawed end, the reading was nearly the same.  However, at the "open end" where one still sees the (now slightly swollen) turns of foil, we get a reading of around 10,000cpm.  If one turned on one's "gamma vision" it would be like a flashlight with a stubby beam, I guess.

I took multiple wraps of Al foil and placed them around the mica window of the GM tube.  Essentially no attenuation of any reading anywhere, until one gets to 4 turns or wraps, at which point there may have been a very slight dropoff - no more than maybe 10%.

Thus I have to say that all of these fun and games are gamma or strong Xray.  Beta component seems negligible.


So I am still scratching my head over the initial rise on solution infiltration, as seen from outside the bucket.

nr

> HI Nick,
> 
> Things are finally stabilizing here, perhaps this winter
> will find
> me doing some more serious research in between cooking up
> the next
> software release.
> 
> As regards your pixie. It should come as no surprise that
> the
> rolls are hot. You must be displacing U from the solution,
> as
> we anticipated. I suspect that is not a stable condition,
> and
> the amount of U in solution vs U plated is in a dynamic
> relation.
> If the temperature is changing, the displacement reaction
> will
> either increase or decrease ( hot or cold respectively ).
> Late
> evening reading would have occurred over the heat of the
> day,
> so should be larger than morning reading. If the diurnal
> variation
> is continuing, draw out a foil roll at each time, and see
> if
> the roll itself is hotter at the evening point.
> 
> Also, look at the bottom of the solution tank. Displaced U
> may be collecting
> there after being shed from the Al foil.
> 
> K.