POLARIZATION MEASUREMENT SYSTEM ON THE VEPP-4 COLLIDER AT LOW ENERGY RANGE

摘要

For carrying out an experiment on a precision measurement of the tau-lepton mass near its production threshold of 1.8 GeV it is necessary exactly to know the. energy of colliding particles. For measurement of beam energy a well known method of resonance depolarization with observation of a polarization degree on the effect of internal scattering of particles in a beam will be used. For this purpose special systems including counters of scattered electrons and plates of the TEM wave depolarizer will be installed on the booster storage ring VEPP-3 and the collider VEPP-4M. To control the measurement system we plan to use PC under Linux integrated into the VEPP-4 control system. Two CAMAC crates with recording units and CAMAC crate with the frequency synthesizer are connected to the PC. The step motors controlled via RS-485 regulate positions of the counters.