Heavy ion accelerator facility front end design and commissioning

Abstract

A new project, high intensity heavy ion accelerator facility (HIAF), is currently under design and construction in China. The HIAF front end, composed of electron cyclotron resonance (ECR) ion sources, low energy beam transport (LEBT) and radio frequency quadrupole (RFQ), will produce and provide beams of ions with a mass up to uranium at a beam energy of 0.5 MeV/u. The typical beam intensity is designed up to 2 emA for the uranium beam with a charge state of 35+. This paper presents an overall design of the front end for HIAF and discusses several key issues in the design. By modeling the beam extraction from the ECR source, we got a reliable starting beam condition to perform the design. Transverse coupling of the beam from the source was elaborated. To relieve the coupling we implanted two solenoids after the source. Space charge effect in the charge state selection of the ion source was evaluated. An overall space charge compensation degree of no less than 70% was predicted. A beam dynamics simulation was performed by using the initial particle distribution obtained from the extraction modeling. The simulation resulted in development of a beam collimation system in the LEBT to confine the transverse emittance. The RFQ design will follow the development of LEAF-RFQ at Institute of Modern Physics, which has successfully commissioned with several beams and demonstrated as an excellent design. Recent beam commissioning results of LEAF-RFQ will also be presented in this paper.