Initial Operation of the Fermilab Antiproton Cooling Ring

The "cooling" of protons by electrons has been studied by the accelerator group at the Institute of Nuclear Physics at Novosibirsk, U.S.S.R.l. They have achieved damping of proton-betatron oscillations by Coulomb interactions with "cold" electrons as described by simple theory. They also observe fast damping when the longitudinal velocities of all the protons and electrons are very nearly the same and the electrons are trapped in a longitudinal magnetic field. This effect results from the extended interaction between the same electrons and protons.