Systematic studies of the LEP working point

The working point, i.e. the fractional part of the betatron tunes, is one of the key parameters for machine operation. This paper reports on systematic studies in LEP on the dependence of beam sizes and beam lifetimes on betatron tunes. For these studies the horizontal and vertical tunes have been varied by an automatic measurement sequencer over the wide range 0.1 to 0.4 and beam sizes and lifetimes have been recorded in parallel.