324-MHz interdigital H -mode drift tube linac for muon acceleration

We have constructed a 324-MHz interdigital H -mode drift tube linear accelerator (IH-DTL) with an alternating phase focusing method. This IH-DTL will be part of a muon linear accelerator (linac) being developed at the Japan Proton Accelerator Research Complex for a precise measurement of the muon anomalous magnetic moment and a search for the muon electric dipole moment. The IH-DTL is 1.45 m long and accelerates muons from β = v / c = 0.08 to 0.28. Low-power tuning was performed using six slug tuners, which reduced the peak-to-peak on-axis field error to 1.4 % . Following 94 h of high-power conditioning, the IH-DTL demonstrated stable operation at the nominal peak power of 390 kW and a duty factor of 0.1%, corresponding to the designed accelerating field ( E 0 ) of 3.6 MV / m . This paper presents the construction, low-power rf tuning, and high-power performance of the 324-MHz IH-DTL.