Development of a variable energy RFQ for cluster acceleration
An RFQ (radio-frequency quadrupole) has been designed and built as a postaccelerator for the cluster accelerator facility at the IPN (Institute de Physique Nucleaire) Lyon, France. The four-rod RFQ resonator is designed for variable energy by means of a variable frequency of the resonator between 80 and 110 MHz. The properties of the RFQ for the typical cluster mass ranges of up to 50 u are discussed and the status of the project is reported.<<ETX>>
Four-rod-λ/2-RFQ for light ion acceleration
Abstract A simple type of RFQ structure with circular rods as electrodes has been developed in Frankfurt. The improved design uses a linear arrangement of supporting stems on a massive common bar. This linear rf structure consists of a chain of λ/2-line pairs and leads to an advantageously simple but nonetheless effective RFQ structure. With this stable cheap type of RFQ resonator preaccelerator prototypes have been built for light ions. New results of electrode and structure optimization and beam measurements are presented.
Optimization of half-wavelength helices
Abstract Calculations of resonance frequencies and fields for short halfwave-length have been made combining sheath model and transmission line theory. The influence of the “end effect” on resonance frequencies and acceleration properties of 1 2 λ- helices is determined. The shunt impedances for 1 2 λ- helices are calculated and applications are discussed. The comparison of theory with measurements shows a good agreement and indicates that this is a practicable method to optimize short helix accelerator sections.