At 08:06 PM 10/27/2009, Horace Heffner wrote:
Here is described what I think is a protocol which is improved over
the Galileo protocol:
http://www.lenr-canr.org/acrobat/MosierBosscharacteri.pdf
Some key points:
"CR-39 detectors (Fukuvi), rectangular in shape with dimensions of 1
cm ° 2 cm ° 1 mm, were obtained from om Landauer and used as
received. Prior to using the CR-39 detector in an experiment, one
corner of the detector was exposed to an 241Am source. This is used
as an internal standard to account for variability in the CR-39
detectors. By having an internal standard on the same detector used
in an experiment assures that both sets of tracks experience
identical experimental and etching conditions."
I would add here that doing the calibration exposure to the Cr-39
with a 241AM source would be a significant value added for the
student or amateur with no legal access to such a source, and who
might not be able to achieve an standardized exposure in any case.
The plan is to use Am-241 from a smoke detector.
Cheap. That's part of the Galileo protocol,
actually. What this shows is the effect of alpha
particles from a known source. Using spacers,
it's possible to estimate the energies of the
particles; what's known from the source is the
initial energy of the particles as they result
from decay, but the actual energies hitting the plastic will vary.
"The rectangular cells (Ridout Plastics) were made of butyrate. A
laser was used to cut a square hole in one side of the rectangular
cell. A silicone based cement was used to epoxy a 6 μm thick Mylar
film over the hole. Figure 1b is a schematic of the cathode. A
square hole is cut inside a polyethylene support. The square hole of
the polyethylene support lines up with the hole in the cell. A Pt
wire and Au wire were mounted on the polyethylene support in such a
manner that, when the cathode is placed in the cell, the Au and Pt
wires are in direct contact with the Mylar film. Polyethylene heat
shrink is used to provide a pressure contact between the Au and Pt
wires. The anode consisted of platinum wire mounted on a polyethylene
support..."
This is a close variation on the Galileo
protocol. It uses a dual cathode, one wire Au and
one wire Pt. I considered doing this version, but
had decided to avoid the complications of that
window. 6 micron mylar. Thin stuff. I have 6 mil
in the basement, I used to do printed circuit
design on it, that dates me a bit, eh?
One complaint: while there are silicone-epoxy
cements, I wouldn't say, using one, what they
wrote, it looks like they used "epoxy" as a
synonym for "glue." I'd have much preferred that
they have stated the exact material used. Because
this could come in contact with the electrolyte, it's important.
Note that use of the Mylar film did not eliminate the tracks: "By
placing a 6 μm thick Mylar film between the cathode and the detector,
it was observed that â¼90% of the energetic particles are blocked.
Using LET curves, a 6 μm thick Mylar film cuts off <0.45 MeV protons,
<0.55 MeV tritons, <1.40 MeV 3He, and <1.45 MeV alphas. However, this
is the energy of the particle when it reaches
the CR-39 detector. It does not take into account the water layer the
particle needs to traverse before it reaches the Mylar film. The Pd
deposit exhibits a cauliflower like structure. Because of this
structure, the particles need to traverse a water layer of varying
thickness. Assuming water thicknesses varying between 0 and 10 μm, it
is estimated that the majority of the particles formed as a result of
Pd/D co-deposition are <0.450.97 MeV protons, <0.551.25 25 MeV
tritons, <1.403.15 MeV 3He, and <1.453.30 MeV alphas.
Yes, I was aware of this experiment, but thanks
for bringing it to mind again. I'm reconsidering
the window. There is some value to doing the
internal CR-39 just to see this hamburger stuff.
What would be valuable would be on the back. But
a mylar window is probably going to stay clear,
and that's an advantage for me if I want to look
at that cathode up close during electrolysis.
CR-39 may become cloudy. Or *will* become cloudy.
But I might put the mylar inside the cell against
the hole instead of outside. This was somewhat my
first design, actually. Pressure of the heavy
water is low, but this way the pressure will hold
the mylar against the window, any glue will just
hold it in place, won't have to resist the
pressure. Then the cathode wires will be against
the mylar. I like the idea of having a gold wire
and a platinum wire, for comparison. Might as
well. Or gold and silver, cheaper. They used
shrink tubing to connect the gold and platinum
wire. So I'll only need a small piece of gold
wire (expensive!) and can use silver wire as the lead. Thanks.
If I put the mylar on the inside, and the piece
of mylar is large, maybe the size of the whole
side of the cell, there will be less exposure of
the electrolyte to the adhesive.
I think pre-etching CR-39 is a very bad idea, because it changes the
CR-39. It is important to have a standard plastic that has undergone
a standard curing cycle, and which is operated in a controlled and
measure temperature range at all times prior to etching. See "Cure
Cycle" here for example:
Otherwise there is no ready determination of what the tracks
represent. Consider, for example, the Kowalsk-SPAWAR debate in the
literature:
Pre-etching is a suggested practice in the CR-39
literature, it exposes fresh CR-39; it won't
"erase" tracks due to neutron or really
high-energy charged particle radiation, but as to
any radon background, it would erase it. It's all
about controls, Horace. If the experimental CR-39
and the controls are pre-etched in the same way,
the objection isn't valid. However, I don't
expect background to be a problem, I mentioned
pre-etching for old CR-39 and, in fact, I think
that may have been the situation it was recommended for.
http://www.lenr-canr.org/acrobat/MosierBossreplytocom.pdf
http://www.lenr-canr.org/acrobat/KowalskiLnuclearorn.pdf
and some background:
http://www.lenr-canr.org/acrobat/MosierBossuseofcrinp.pdf
http://www.lenr-canr.org/acrobat/KowalskiLcommentson.pdf
I think there is a lot more of this stuff on Kowalski's site:
http://pages.csam.montclair.edu/~kowalski/cf/index.html
I've read a lot of Kowalski's stuff, but still not enough!
It is also true the etching cycle itself has to be well controlled.
Just using a hot plate, in whatever ambient temperature happens to
exist, to achieve the etching, is going to produce highly variable
results. Disposable etching containers of some kind might be a good
idea too, and fresh made NOH too, because radioactive contamination
of the etching fluid (e.g. with Rn) is a real possibility, as well as
concentration changes with repeated use. (These are real problems,
not just my imagination.)
NaOH is cheap. LR-115 is also etched with NaOH,
but for less time. The 6 micron cellulose acetate
etches quickly, leaving a 10 micron diameter hole
in the acetate layer, clean through it, and the
polyester underneath is unaffected. The opening
is then easily seen -- by the naked eye,
actually, as a point of light -- and can be
counted with relative ease. If I'm going to put
mylar against the cathode, I can use LR-115
entirely, forget about the CR-39! As to
radioactive contamination of the etching bath,
sure, there will be some because of the ubiquity
of radon, but ... controls, etched at the same
time in the same bath. Neutrons won't affect the
thin cellulose acetate layer except rarely, but
they will then generate knock-on protons from the
polyester, I believe, so another piece of LR-115
behind it will pick up knock-on protons and then
I'll put in a piece of boron-10 just for fun.
I.e., to see if there are any slow neutrons,
detected by yet another LR-115 detector beyond
it. And then another piece of LR-115, facing out,
looking for background or some external radiation
source, and another piece of mylar to keep the
dust off. A whole stack of detectors.
I have to be careful of static charges on the
detectors attracting radioactive dust, that's a known effect.
