On Sep 13, 2011, at 11:50 AM, Peter Heckert wrote:
Horace,
thank you very much. I dont have the knowledge to calculate this.
Only know the very basics.
Found this via google:
<http://itcanbeshown.com/NERS425/Lab5/Shielding%20-%20Final%
20Version.pdf>
There is data about screening.
Yes. They provide an *average* linear attenuation coefficient for
Co60 of 0.694 cm−1, which is 0.694/cm. I provided estimates of .707/
cm and 0.65/cm for the two differing types of gammas. My estimates
were based on numbers I pulled off a graph of attenuation by mass
coefficients, so have some error. Still, I am right on the range
provided by the paper you reference. The bottom line is that 2 cm
lead provides practically no shielding for Co60 gammas.
Using the attenuation coefficient from your referenced article of
0.694/cm, we have:
I = I0 * exp(-(0.694/cm)*(2 cm)) = I0 * exp(-1.388)
I = I0 * 0.25
This means 25 percent of Co60 gamma radiation would get through the
Rossi lead shielding.
My idea was, it could be a very small and weak source, such as used
in schools for physics lectures.
These are not too dangerous if shielded.
If a 2 cm thick lead shielded source has even a very modest amount of
Co-60 then detectors nearby will detect the gammas - at all times.
If the gamma source is very small the intensity should also decrase
by square of distance. The source could be very close to - or
inside the nickel powder core . Then the lead and the distance
together could shield it close to natural baseline level.
Its just an idea. I dont know if this is possible.
This is not possible if the source produced enough radioactivity to
have any effect. Cosmic rays are very detectable and energetic
enough to have an effect on LENR if a near background level of Co-60
can have an effect. A a background level of radiation the radiation
would have to trigger a significant chain reaction to produce
measurable heat. Cosmic rays should trigger such a chain reaction too.
It is also notable that Co60 gammas have enough energy to trigger
positron-electron pair generation. Coincidence counters were placed
up close to the experiment (one on each side) and detected none.
It also was an idea of me, that metal hydrides are very well
researched. Metal hydride hydrogen storage systems are in use
worldwide and they use specially developed alloys also such that
use nickel as a component. These sytems are belived to be the most
secure devices, melting or explosion or abnormal heating is not
reported. Some of these are used with very high pressure and
temperature.
So there are already thousands if not millions man-years of
experience, R&D and scientific research done for metal hydride
systems. systems. But only the LENR researchers find LENR
reactions. Why?
Except for rare explosions, LENR researchers for the most part have
had difficulty reliably measuring the effects, they are typically so
small. Metal hydride storage systems usually require heating
systems, involve large temperature variations, and large reaction
enthalpies. LENR effects would not even be noticed unless very
robust, which is highly unlikely. Secondly, (relatively) very
little LENR research has been done on ordinary hydrogen. Most
research has been done on deuterium based systems.
If LENR reactions where easily to achieve, then this should have
been discovered.
LENR reactions are *not* easy to achieve at this point (unless of
course Rossi is on to something that makes it easy.)
The developers try to reduce the thermal hysteresis in the load/
unload cycle to get best efficiency. So they search for zero
hysteresis.
When there is LENR energy production then we should have negative
hysteresis and if this is possible by common chemical or physical
methods, the countless researchers and scientists should have
discovered this method or catalyzer.
Pretty difficult to say, not knowing what Rossi's method is, or even
if it works as advertised.
Now, so the Rossis catalyzer must be something very unusual that
nobody would ever try to use for a metal hydride storage system.
Agreed.
So we need something that ionizises or atomizes the hydrogen
molecules, and something that is very unusual for hydride systems.
So I came to the idea it must be a radioactive gamma source or
device. And it must be separated from the nickel, but can be very
close and very small and can be inside..
There have been numerous reports of limited success with radiation
stimulation of loaded lattices. Mostly these involved betas
(electrons from electron microscope guns or accelerators), alphas, or
neutrons.
Also I think, we should not only think about the energy, but also
about frequencies and resonances. If Cobalt60 decays into Nickel60,
then the gamma radiation spectrum should contain frequencies that
are in tune with the resonance frequencies of the nickel nucleus or
the inner electron shells of the nickel atom.
That is some good thinking.
That was my idea and how I came to it.
Best,
Peter
The problem with the idea is the number of gammas required to trigger
enough reactions to produce measurable heat (unless of course a chain
reaction is involved.) Suppose 1 watt of heat is produced, and the
reaction involved releases on the order of 10 MeV energy (it is
probably way less if it is a Ni transmutaion.) Each second a J of
energy has to be produced. A J is 6.24x10^18 eV, or 6.24x10^12 MeV.
At 10 MeV per reaction, that is 6.24x10^11 reactions, requiring
6.24x10^11 gammas for that second. That is a highly lethal source
of gammas! Further, since we are talking about 1.33 MeV gammas, that
is 4.69x10^12 gammas per second, or 0.133 J worth of gammas for that
second. The radioactive source would produce about a tenth of a watt
heat. If Rossi's reactor produced 13 kW, then the Co60 source would
produce about a kW all on its own, and that assumes all the Co60
gammas result in an LENR reaction. This would be a highly detectable
radiation source.
[snip older material]
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
