First results of quasi-isochronous operation at LNLS

We have started a program at LNLS to implement a quasi-isochronous operation mode at the 1.37 GeV electron storage ring. The aim is to explore nonlinear longitudinal beam dynamics along with the reduction in the electron bunch length. To characterize the modes we have set up an electron bunch length measurement system which uses the visible light emitted from a bending magnet and a commercial fast photodiode with a sampling oscilloscope. The synchrotron oscillation frequency and the orbit displacement were also measured as a mean to assess the momentum compaction factor /spl alpha/. Up until the moment a reduction of a factor of 13 in /spl alpha/ was obtained.