lew (04/22/83)
I recall that the most energetic cosmic rays have energies in excess of 1e20 eV. They are talking about teravolts ( 1e12 eV ) for these new accelerators, so I'm not worried. Cosmic rays include all high energy particles that reach the earth, so they are almost by definition the highest energy particles in nature that we know of. It is my impression that theorists are hard put to come up with mechanisms to account for the observed energies. Lew Mammel, Jr. ihuxr!lew
don (04/23/83)
Subject: high energy particles Gravitational and nuclear processes in space don't produce particles with really impressive enegies (a few Mev). Occasional cosmic rays have energies that are far beyond what any man-made accelerators can produce. I forget the exact numbers, but the comment about the tennis ball is often used to illustrate. Convert a foot-pound to electron-volts and you will have a ballpark figure. These particles are not created with these energies, but are accelerated by moving magnetic fields in space . The super high energy particles are thought to be extragalactic since particles cannot get to those energies by bumping around within the galaxy.
don (04/24/83)
Subject: more than you want to know about cosmic rays
Super energetic cosmic rays are very rare. Most cosmic rays are only a
few kev, altho it is hard to study them this close to the sun. Very
low energy particles are reflected by the sun's magnetic field.
Things like quasars are thought to be driven by gravitation infall.
Nuclear processes cannot produce as much energy (a few percent mass to
energy conversion compared to 20 or 30 percent for collapse into a
black hole). At one time scientists were mystified by these objects
because they radiated more energy than nuclear fusion could produce.
Most of this energy is in the form of X-rays and not terribly high per
particle.
I worked for several years with the HEAO-C satellite which had a
detector for the Heavy-Nuclei component of cosmic rays. Most cosmic
rays are protons or helium, but we saw everything up to high energy
lead and platinum. Like all elements beyond iron, these nuclei are
thought to be the product of super nova explosions ("rapid process")
and/or gradual neutron capture ("slow process").