Development of high gradient IH linac

We have studied Interdigital-H (IH)-type structures for application in heavy-ion inertial fusion (HIF) and other projects, at the Tokyo Institute of Technology (TIT). We have developed an IH linac with a high acceleration rate. It makes use of the fact that IH linacs have 5–10 times as high shunt impedance as Alvarez and RFQs in low and middle regions of energy [1–5]. We calculated trajectories of particles and made experiments by model cavities. Now an IH linac that we call high gradient IH linac is under construction. The calculated result of particle dynamics is that the transverse acceptance and an acceleration rate of this linac are 113π mm mrad and 5.5 MV/m, respectively. This linac is able to accelerate particles with a charge to mass ratio (q/A) greater than 1/16 from 219 keV/u up to 600 keV/u. The cavity length of this linac is 1120 mm. The frequency is 81 MHz.