Speaker
Description
The Linac Coherent Light Source II (LCLS-II) has been in user operations since 2023 and has successfully ramped up the beam repetition rate to 93 kHz. The LCLS-II photoinjector has demonstrated the ability to deliver a high-brightness, low-emittance electron beam at high repetition rates, meeting key performance targets. However, several operational challenges have emerged during commissioning and user operation. These include substantial gun dark current, degradation of cathode quantum efficiency (QE) manifesting as QE craters, unexpected electron beam splitting, significant emittance growth through the laser heater chicane, complications during laser heater commissioning, the presence of beam halos, cathode's QE dependence of the e-beam rate. This paper provides an overview of these challenges and highlights recent efforts to address these outstanding issues, and discuss plans for further improvement of the performance.
| Paper status | Resubmitted proceeding files received and assigned to an editor. Accepted by Submitter. |
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