TU Darmstadt, Darmstadt, Germany
Cornell University, Ithaca, New York, USA
The Superconducting Linear Accelerator S-DALINAC at the University of Darmstadt (Germany) is a recirculating linac with two recirculations providing beams for measurements in nuclear physics at small momentum transfers. For these experiments an energy spread of better than 10-4 (rms) is needed. Currently acceleration in the linac section is done on crest of the accelerating field. The recirculation path is operated achromatic and isochronous. In this recirculation scheme the energy spread of the resulting beam in the ideal case is determined by the electron bunch length. Taking into account the stability of the RF system the energy spread increases drastically to more than 10-3 (rms). We will present a new non-isochronous recirculation scheme which helps cancelling out these errors from the rf-control. This scheme uses longitudinal dispersion in the recirculation paths and an acceleration off-crest with a certain phase with respect to the maximum. We will present results of the commissioning of the new system including measurements of the longitudinal dispersion in the recirculation arcs as well as measurements of the resulting energy spread using an electron spectrometer.
TU Darmstadt, Darmstadt, Germany
Cornell University, Ithaca, New York, USA
The Superconducting Linear Accelerator S-DALINAC at the University of Darmstadt (Germany) is a recirculating linac with two recirculations providing beams for measurements in nuclear physics at small momentum transfers. For these experiments an energy spread of better than 10-4 (rms) is needed. Currently acceleration in the linac section is done on crest of the accelerating field. The recirculation path is operated achromatic and isochronous. In this recirculation scheme the energy spread of the resulting beam in the ideal case is determined by the electron bunch length. Taking into account the stability of the RF system the energy spread increases drastically to more than 10-3 (rms). We will present a new non-isochronous recirculation scheme which helps cancelling out these errors from the rf-control. This scheme uses longitudinal dispersion in the recirculation paths and an acceleration off-crest with a certain phase with respect to the maximum. We will present results of the commissioning of the new system including measurements of the longitudinal dispersion in the recirculation arcs as well as measurements of the resulting energy spread using an electron spectrometer.
CERN, Geneva, Switzerland
