At 05:39 PM 10/30/2009, Jed Rothwell wrote:
Abd ul-Rahman Lomax wrote:
But as I said, with other less sensitive methods of detecting
neutrons I do not think anyone has ever seen neutrons in the
absence of heat, whereas heat without neutrons has often been
seen. So it seems clear to me that heat is the more reliable signal.
Sure. If you eliminate all the various techniques that are "sensitive"!
Let us not confuse insensitive with inconsistent, or unreliable.
Jed, CR-39 is quite reliable if not used in a wet configuration.
Remember, as well, that it was electronic methods which produced
erroneous reports of higher levels of neutrons. SPAWAR claims that
the triple-track results are quote reliable. Remember, the
controversial stuff is on the front side of the CR-39, the neutrons
are mostly on the back, where one is looking down at the point of
origin. On the front, that point of origin, by the time you have
etched down to show pits, is gone. Those dual-focus triple track
images are spectacular, you see three little grooves at the bottom of
this triple pit.
Insensitive techniques will miss seeing low levels of neutrons
altogether. But they will see high levels reliably. And they do.
Indeed.
They definitely detect bursts from time to time, but these bursts
are not correlated with heat or anything else as far as I know.
Well, they are correlated with loaded palladium deuteride, I believe.
However, it is this kind of radiation detection which tells us
nothing other than that the excess heat isn't from a reaction that
directly generates neutrons. However, the secondary neutrons may
indeed be quite regular; the problem is that the level is low enough
that you need an integrating detector, or a very noise-free electronic one.
There is no doubt that bursts of neutrons come and go. Perhaps
there is also a very low level flux that continues consistently,
yet it cannot be easily detected with at BF3 (who knows why) and it
is correlated with heat and other effects. This might be what the
CR39 detects. That's a long string of "perhaps" "maybe" and "ifs."
I think that's exactly what CR-39 detects. But ... I've come to
doubt, through reflection on the Earthtech work, that there is clear
evidence of alpha radiation from the primary reaction, beyond some
very good reasons to expect it (helium). I'd want to go back and take
a long, hard look at the hamburger, and then at what is beyond it.
There seems to have been an assumption that the hamburger was due to
heavy damage, i.e., overexposure of the CR-39. Maybe. Maybe not. But
none of this applies to back side tracks, plentiful when a gold
cathode is used. How many of these are triple-tracks? If I have a
piece of LR-115 immediately behind a piece of CR-39, I should see,
with triple tracks, three separate pits at the right location. That
would not be background, unless it was background neutron radiation
coming from the direction of the cathode.
Accordingly, I've bought a pile of 250 micron clear polycarbonate
sheet. Big sheets, that I will cut up. If I'm lucky, it won't get
soggy in the cell, if it's inside. I'm aware of the risk that this
stuff has been long exposed to radon, but I want to see what happens,
and I'll get some practice etching as part of the bargain. I now
intend to cut it into pieces that will fit inside the case, the whole
side, and I might even put two in there. Once the primary search is
for neutrons, who cares about hamburger on one side, the side where
you wouldn't see the neutrons to any degree anyway? These are all
really cheap approaches, and, if I get lucky or turn out to have good
intuition, I won't have to say to myself, well, it was stupid, but at
least it was cheap. Think of the fortunes spent on approaches that didn't work.
