Development of a 325 MHz Ladder-RFQ of the 4-Rod-Type

For the research program with cooled antiprotons at FAIR a dedicated 70MeV, 70mA proton injector is required. In the low energy section, between the Ion Source and the main linac an RFQ will be used. The 325MHz RFQ will accelerate protons from 95 keV to 3MeV. This particular high frequency for an 4-ROD type RFQ creates difficulties, which are challenging in developing this cavity. In order to define a satisfactory geometrical configuration for this resonator, both from the RF and the mechanical point of view, different designs have been examined and compared. Very promising results have been reached with a ladder type RFQ, which has been investigated since 2013 [1, 2]. We present recent 3D simulations of the general layout and of a complete cavity demonstrating the power of a ladder type RFQ as well as measurements of a 0.8m prototype RFQ, which was manufactured in late 2014 and designed for RF power and vacuum tests. The prototype manufacturing was completed and first measurements are shown.