Initial comgissionings of the Advanced Photon Source (APS) 7-GeV storage ring and its diagnostics systems have bwn done. Early studies involved single-bunch measurements for beam transverse size (ox 150 pm, oy = 50 pm), current, injection losses, and bunch length. The diagnostics have been used in studies related to the detection of an extra contribution to beam jitter at -6.5 Hz frequency; observation of bunch lengthening ((3 = 30 to 60 ps) with single-bunch current; observation of an induced

more »

... ertical, head-tail instability; and detection of a small orbit change with insertion device gap position. More recently, operations at 100-mA stored-beam current, the baseline design goal, have been achieved with the support of beam characterizations.