I'm learning more and more how different the worlds of quantum mechanics and high energy physics are from that of everyday experience.
There's been an ongoing discussion about the viability of "active gamma suppression," or the quenching of gammas, during a LENR reaction. This is an interesting question because its outcome tells us something about the kinds of reactions that are possible in light of the available experimental evidence. In this context the question of the viability the quenching of gammas under any circumstances is an important one. I'm starting to collect a number of interesting articles and links that seem to be relevant here, which I hope to put together in an email at some point. But before I do that I wanted to share this particular link, which seems promising: "Automatic quenching of high energy γ-ray sources by synchrotron photons" http://arxiv.org/pdf/astro-ph/0701633.pdf We investigate a magnetized plasma in which injected high energy gamma rays annihilate on a soft photon field, that is provided by the synchrotron radiation of the created pairs. For a very wide range of magnetic fields, this process involves gamma-rays between 0.3GeV and 30TeV. We derive a simple dynamical system for this process, analyze its stability to runaway production of soft photons and paris [pairs], and find conditions for it to automatically quench by reaching a steady state with an optical depth to photon-photon annihilation larger than unity. We discuss applications to broad-band γ-ray emitters, in particular supermassive black holes. Automatic quenching limits the gamma-ray luminosity of these objects and predicts substantial pair loading of the jets of less active sources. Some important details here -- the gammas that are thought to be quenched are 10 to 1,000,000 times more powerful than the ones we're interested in. So even though the conditions under which the quenching is thought to happen are extreme, these ranges also provide an upper bound that is well above what we would need. It is possible that the effect cannot be seen below these energies, but perhaps it might. The authors require a magnetic field, but they suggest that the effect can be seen between 10^-9 and 10^6 G. The lower bound, 10^-9 G, is what you find in the human brain, and the upper bound, 10^6 G, is greater than but not too different from the magnetic field of a magnetic resonance imaging machine. The authors mention in passing a related paper looking at the nonlinear effects of pair production generated by ultrarelativistic protons. A recent article at phys.org discusses how laser light coherently accelerates protons in a metal foil at higher energies than previously thought. http://phys.org/news/2012-07-higher-energies-laser-accelerated-particles.html So we could potentially have ultrarelativistic protons in our optical cavity, yielding pair production. The pair production cross section in nickel also becomes non-negligible in the energy range of 1 to 30 MeV. http://imgur.com/MrE0K Eric
