Design and beam dynamics of a 400 kW D+ linear accelerator to generate fusion-like neutrons for breeding blanket tests in Korea

Recently, a pre-conceptual design study was conducted in Korea for developing a dedicated linear accelerator (linac) for 400 kW (40 MeV, maximum 10 mA CW) deuteron (D${}^{+}$) beams to generate fusion-like neutrons. The accelerated beam hits a solid Beryllium target to produce fusion-like neutrons, which will be utilized for technical feasibility tests of the breeding blanket including tritium production and recovery. In this work, we present detailed start-to-end simulation and machine imperfection studies with proper beam tuning to assess the target beam availability and validate the machine specifications. We have designed a 2.45 GHz ECR ion source and a 4-vane type 176 MHz RFQ by using IBSimu, Parmteq, and Toutatis simulation codes. We propose a super-conducting linac with HWR cavities and solenoid-focusing magnets to accelerate the beam up to 40 MeV. In the HEBT line, we adopt two octupole magnets and subsequent quadrupole magnets to make a rectangular-shaped and uniform density beam with 20 cm $\times$ 20 cm footprint at the target. Extensive beam dynamics studies along the linac have been performed using the TraceWin simulation code.