THIALH2070
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
We have developed a cost-effective, fast rotating wire scanner for use in accelerators where high beam currents would otherwise melt even carbon wires. This new design uses a simple planetary gear setup to rotate a tungsten or carbon wire, fixed at one end, through the beam at speeds in excess of 20 m/s. We present results from bench tests, as well as transverse beam profile measurements taken at Cornell’s high-brightness ERL photoinjector, for beam currents up to 35 mA.
THIALH2071
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
We evaluate the effectiveness of three ion-clearing strategies in the Cornell high intensity photoinjector: DC clearing electrodes, bunch gaps, and beam shaking. We present data from recent experiments where we directly measured the residual trapped ion density while employing these clearing methods. Several theoretical models have been developed to estimate the ion creation and clearing rates. The data is well explained by two independent simulation codes that track the motion of ions trapped in the electric field generated by the beam.