Semi-analytic estimates of the beam lifetime seem to be an essential complement. Presently schemes to correct the resonance effects are being developed and will be tried out this year. It will also be of great interest to see how high we can go with the beam-beam parameter. Studies of transverse beam polarization at energies above 50 GeV continue to be of interest in connection with the enormous effort made to calibrate the beam energy and take detailed account of the many phenomena that can affect it. On the collective effects side, detailed calculations of impedance and loss factors continue and an impedance database has been implemented.
Strong scraping leading to short beam lifetimes is used to calibrate the loss monitors.
The loss monitors are sufficiently linear and sensitive to measure beam tails corresponding to life times of several thousand hours down to minutes. As presented in the EPAC 96 in Barcelona, significant non-Gaussian beam tails have been observed in LEP both in the horizontal and vertical plane. The results are compared to theoretical tracking studies. More recently, using additional collimators in regions with and without dispersion, the importance of the combined effect of energy loss in the scattering processes and dispersion to launch particles at large amplitudes could be demonstrated. Comparing tail scans for small and large emittances and various optics has also become a very useful tool to study beam dynamics close to the dynamic aperture.