First Operational Experience with DORIS II
DORIS II is a completely new designed e+-e- storage ring with a mini-beta scheme. After first runs with a 8 cm optic, the vertical amplitude functions in the interaction points were reduced to 4 cm. This yielded luminosities of L = 1.5 . l031 cm-2sec-1 with 2 × 27 mA at E = 5 GeV. Because of the short injection time, an integrated luminosity of more than 600 nb-1 per day has been obtained.
Present Limits for the Luminosity, the Beam Current and the Beam Lifetime in DORIS II
The e e storage ring DORIS II has been operating for high energy physics experiments in the region of the Y resonances around 2x5 GeV and as a source for synchrotron radiation near 3.7 GeV. A luminosity of nearly 3x10T cm Ssec or more than 1500 (nb) /day has been achieved. For synchrotron radiation e -currents of about 100 mA are stored in 4 bunches (out of 480 buckets). As long as the beam-beam interaction does not limit the luminosity the optimum performance of the ring is obtained for both modes of operation if the currents stored are large, the cross section of the beam is small and the lifetime is long. Thus we concentrate the discussion on these subjects.
Absorption measurements of copper, silver, tin, gold and bismuth in the far ultraviolet
Abstract The absorption coefficient of Cu, Ag, Sn, Au and Bi films of thickness from 50–6500 A have been studied in the spectral range from 50–350 A using the synchrotron radiation of the 6 GeV electron synchrotron DESY.