Figure 3
The two APS storage-ring modes used for ∼100 ps time-resolved experiments at BioCARS. The common operating mode has 24 bunches circulating with 4.25 mA per bunch and 153.4 ns separation between the bunches. The bunch length in this mode is 79 ps (FWHM). The hybrid mode has a 16 mA bunch separated from adjacent septuplets by 1.59 µs. The bunch length in this mode is 118 ps (FWHM). There are three 12-week runs per year at the APS, with hybrid mode accounting for ∼17% of the total run cycle and 24-bunch mode accounting for ∼60%. In both modes periodic top-up of the individual bunches maintains the total ring current at 102 mA. |