Development of Superconducting Linac for the Kek/Jaeri Joint Project

TL;DR

This paper presents the design, development, and testing of a superconducting linac for the JAERI/KEK joint project, including cavity R&D, system design, and dynamic Lorentz detuning modeling.

Contribution

It introduces a new superconducting linac design for high-intensity proton acceleration and provides experimental validation of cavity performance and Lorentz detuning models.

Findings

Vertical tests achieved maximum electric surface fields of 23MV/m and 31MV/m.

The Lorentz detuning model was validated through experiments.

The linac design meets the requirements for subsequent use as an injector to a 3GeV RCS.

Abstract

The JAERI/KEK Joint Project for the high-intensity proton accelerator facility has been proposed with a superconducting (SC) linac option from 400 MeV to 600MeV. System design of the SC linac has been carried out based on the equipartitioning concept. The SC linac is planned to use as an injector to a 3GeV rapid cycling synchrotron (RCS) for spallation neutron source after it meets requirement to momentum spread less than +-0.1%. In the R&D work for SC cavities, vertical tests of single-cell and 5 cell cavities were performed. Experiments on multi-cell (5 cell) cavities of b=0.50 and b=0.89 at 2K were carried out with values of maximum electric surface peak fields of 23MV/m and 31MV/m, respectively. A model describing dynamic Lorentz detuning for SC cavities has been developed for pulse mode operation. Validity of the model was confirmed experimentally to simulate the performance.