Interdigital H mode drift tube linac design with alternative phase focusing for muon linac
We have developed an inter digital H mode (IH) drifttube linac (DTL) design with an alternative phase focusing (APF) scheme for a muon linac, in order to measure the anomalous magnetic moment and electric dipole moment (EDM) of muons at the Japan Proton Accelerator Research Complex (J PARC) The IH DTL accelerates muons from b v/c 0.08 to 0.28 at an operational frequency of 324 MHz. The synchronized phase array is optimized with analytical calculation of the beam dynamics to get smaller emittance growth during acceleration. Then an IHDTL cavity is modeled in the 3D EM simulation. Finally the beam dynamics in the cavity are evaluated numerically. The output beam emittances are calculated as 0.315p and 0.195p mm mrad in the horizontal and vertical directions, respectively, which satisfies the experimental requirement. Additional emittance growth due to an error field caused by fabrication error is evaluated to be less than 10% with eight slug tuners. The design and results are described in this paper.