We report on a week-long study of a conceptual design of EUV FEL light source based on an energy recovery linac with on-orbit laser plasma accelerator injection scheme. We carried out this study during USPAS Summer 2023 session of Unifying Physics of Accelerators, Lasers and Plasma applying the art of inventiveness TRIZ. An ultrashort Ti-sapphire laser accelerates electron beams from a gas target with mean energy of 20 MeV, which are then ramped up to 1 GeV in a five-turn scheme with a series of fixed field alternating magnets and two superconducting RF cavities (100 MeV per cavity per turn). The electron beam is then bypassed to an undulator line optimized to generate EUV light of 13.5 nm at kW level in a single pass.

The Dual-Axis Radiographic Hydrodynamic Test Facility (DARHT) uses a spinning wheel debris blocker as a crucial machine protection system to prevent target debris from the electron to X-ray conversion process from traveling upstream and damaging the accelerator. The spinning wheel in use on DARHT Axis-I consists of two spinning disks normal to the beamline, each with an open slit that crosses the beamline at frequencies of 50 Hz and 40 Hz, creating an opening at a beat frequency of 8 Hz allowing the electron beam to pass through and shut behind it. In this poster, we present steps taken to improve the reliability and performance of the spinning wheel, which include replacing legacy and custom diagnostic components with off-the-shelf hardware. We also present the challenges and solutions in testing and deploying these upgrades without disrupting operation of the accelerator.