Thresholds of transverse instability of bunched beam in proton synchrotron

The paper contains an overview of theory of transverse coupled-bunch coherent instabilities at the head-tail modes. Special attention is paid to threshold calculations of the instability being caused by narrow-band resonators. Effect of chromaticity and cubic-nonlinearity correction of the magnetic field is taken into account. A set of formulae and graphs suitable for practical calculations is presented. The tolerable values of transverse coupling impedances at parasitic higher-order E1np-modes of the UNK accelerating cavities are estimated. 9 refs., 4 figs