Electromagnetic interaction of colliding beams in storage rings

A particle of one beam passing through the interaction region will be influenced by the electric and magnetic fields produced by the entire other beam. Clearly, this classical electromagnetic interaction between the two beams will perturb the motion of the particles circulating in the machine. The author presents the basic aspects of this beam-particle force. How the effect of this electrical force is quite different in the case of continuous (unbunched) proton beams which cross each other at an angle (as in the ISR at CERN and the ISABELLE at Brookhaven), as compared to the case of electron-positron bunches which collide heat on (as in the SPEAR II Ring and in PETRA and PEP) is indicated. (1 refs).