T. Holmquist et Jt. Rogers, A TRAPPED PHOTOELECTRON INSTABILITY IN ELECTRON AND POSITRON STORAGE-RINGS, Physical review letters, 79(17), 1997, pp. 3186-3189
An anomalous growth of the horizontal coupled bunch modes of the bunch
ed beam is observed in the Cornell Electron Storage Ring. In contrast
with instabilities caused by electromagnetic wake fields, the growth r
ate is a highly nonlinear function of the bunch charge. We show that t
his effect is due to photoelectrons produced by synchrotron radiation
which are trapped in the beam chamber by the bending magnet field and
a quadrupole electrostatic field. We have developed a numerical simula
tion and an analytical model of this process. [S0031-9007(97)04354-8].