At 11:00 AM 10/8/2012, Jones Beene wrote:
Well, one wonders if some of the "triple tracks" have not been
misidentified, given the known miniscule cross-section of C-12 for thermal
neutrons and lack of fast neutrons in LENR. There are simply too many triple
tracks for even a year of exposure$B!D(J
Triple tracks are considered diagnostic for fast neutrons. The
materials are not sold for use with slow neutrons, unless there is a
converter screen, either natural boron or, for better results,
boron-10. In that case, what the material shows is the generated alphas.
The SPAWAR reports are claiming, in fact, 14 MeV neutrons. There is
not exactly a "lack" of fast neutrons in LENR. Rather, the levels of
neutrons reported have been so low as to be difficult to distinguish
from noise, using electronic detectors. Solid state nuclear track
detectors (SSNTDs) can accumulate tracks over a long period; in the
SPAWAR triple-track reports it might be for six days or longer.
One should understand that the SPAWAR results have on the order of
ten triple-tracks (or less) per chip, the chips being 1 cm x 2 cm x 1
mm thick. Background may be about one triple-track.
WERE IT NOT FOR THE INTERPRETATION. Is it valid logically?
If you look carefully at the images the bubbles are NOT compatible with
three identical ions (in mass/energy) and they should be if there were
really three alphas. Instead, usually there is one larger bubble (the center
one that is often larger and the other two, which are themselves not
identical.
I don't know that it's necessary that the alphas have equal velocity.
The momentum must be distributed to match the original momentum.
The angle of incidence of the original neutron, and the actual site
where the carbon interaction takes place, may produce differing
visibility for the individual tracks.
This old paper indicates why boron was initially added to CR39.
http://www.tandfonline.com/doi/abs/10.1080/18811248.1984.9731126#preview
... and it is simply to narrow down the interpretation of the source, as
boron does not respond to gammas. Problem is: Boron is not always added to
CR39, and if it is not labeled as being added, then the suspicion can be
that B is absent. This would be a reason to eliminate it - as well as the
false assumption that boron does not produce triple tracks.
If there are fast neutrons, boron will have little effect. It's only
if there are slow neutrons that boron is used.
First - Is it valid to assume no boron, if the film is not labeled as such?
Yes. At least no significant boron.
If not, or if the film is known to have boron, then the triple tracks could
be a relic of boron interaction. It does not take much boron as a
contaminate, given the extremely high cross-section (millions of times
higher than for C12)
That probability - of the assumption of no boron based on labeling alone -
may be similar to why food processors must disclose whether the same
equipment was used with peanuts and other allergens. Can you trust a
supplier of film for that kind of full disclosure? If not, then it throws a
wild-card into the interpretation.
These materials are sold for radiation dosimetry. That can be a
critical application. I'd be astonished if there was significant boron.
LR-115 is sold with an overlayer of boron, if that's what you want.
Speaking of "it's all about interpretation": - This reaction below is
actually a triple track, although on first blush - it would be categorized
as double.
10B + n $B"*(J [11B] $B"*(J $B&A(J + 7Li
Not only is it triple track, because the 11 boron actually is dislocated far
enough on impact with the neutron to cause the central bubble - but also,
the two which split off from the 11B (in this interpretation of triple
tracks) are the right size range for them to be consistent with the images
$B!D(J the ones which claim the triplets are from C12 disintegration.
This is an alternate interpretation. It indicates only that there are other
logical interpretations of triple tracks - which may or may not be more
cogent than C12, when the cross-section is factored in.
These aren't "bubbles," just to nit-pick. What is seen in the images
are pits. The CR-39 is etched down from the surface, and the part of
a track that is closest to the surface is etched the most. In
addition, it appears, as a particle slows, the energy transferred per
micron increases, so tracks would get fatter just from that.
If there is a "bubble," it wouldn't be from radiation, it would be a
process defect in the CR-39.
The bottom of a pit is etched the least. As you continue to etch
CR-39, the normal surface is also etched away to some degree, so any
features that appear as pits will grow with time.
The degree of confusion that can result in interpretation of CR-39
material, the kind used by SPAWAR, could be great. That's why I'd
prefer, if I were going to use CR-39, to either use very thin
material, if it can be obtained, or create it by evaporating a
solution of the material, which is a technique that has been used to
create radioautographs of cells that have absorbed a radioisotope.
This is one reason why I went toward LR-115, which is sold, in one
form, as a 100 micron polyester base with a 6 micron cellulose
nitrate sensitive layer, that is dyed deep red. With alpha tracks,
from Am-241, and the recommended etching (which is at a lower
temperature, lower concentration of NaOH, and lower time than
recommended for CR-39), the tracks are very clear, and mostly result
in clear openings in the red layer, they are easily seen and
distinguished from Other Stuff. Cones are also visible, that
terminate with these clear, larger openings. Occasionally, one can
see a track that veers, apparently from some near-collision. And
features are visible that don't result in a clear opening.
Interpreting all this is not necessarily a simple task, even with
LR-115, which produces more easily discriminated radiation tracks!
I have seen, so far, one triple-track, searching across the surface,
still incompletely, of a single detector, 1 cm x 1.5 cm. I'm not
seeing anything that looks like proton knock-on, not clearly, and I'm
suspecting that the films may not have been adequately etched to show
protons. They are sold for that purpose, though, so I'm still
researching all this. Or I didn't get a reaction and the tracks I
have are background (which could easily be true.)
The "original message" quoted below was not from me. Rather, it was
something I quoted at the start of my post.
-----Original Message-----
From: Abd ul-Rahman Lomax
AFAIK fast neutrons are detected by the fact that they occasionally
break a C12 nucleus into 3 alpha particles. It is the three alpha
particles that produce three cone shaped tracks in the CR39, with a common
origin.
Common origin yes - but NOT a similarity in mass energy, since the bubbles
vary considerably
