• U. Bartz, A. Bechtold, J.M. Maus, N. Mueller, A. Schempp
  IAP, Frankfurt am Main

A short RFQ prototype was built for tests of high power RFQ structures. We will study thermal effects and determine critical points of the design. Simulations with CST Microwave Studio and first measurements were done. First results and the status of the project will be presented.

• J.M. Maus, U. Bartz, R.A. Jameson, N. Mueller, A. Schempp
  IAP, Frankfurt am Main

For the development of high energy and high duty cycle RFQs accurate particle dynamic simulation tools are important optimize designs especially in high current applications. To describe the external fields in RFQs the Poisson equation has to be solved taking the boundary conditions into account. In the newly developed subroutines this is done by using a finite difference method on a grid. The results of this improvement are shown and compared to the old two term and multipol expansions.

• P. Kolb, N. Mueller, A. Schempp
  IAP, Frankfurt am Main

The goal of the Frankfurt Funneling Experiment is to multiply beam currents by merging two low energy ion beams. In an ideal case this would be done without any emittance growth. Our setup consists of two ion sources, a Two-Beam-RFQ accelerator and a multi cell deflector which bends the beams to one common beam axis. Current work is the design of a new beam transport system between RFQ accelerator and deflector. With extended RFQ-electrodes the drift between the Two-Beam-RFQ and the rf-deflector will be minimized and therefor unwanted emittance growth prohibited. First rf measurements with a scaled experiment will be presented.

• N. Mueller, U. Bartz, D. Ficek, P. Kolb, J.M. Maus, A. Schempp, M. Vossberg
  IAP, Frankfurt am Main

Funneling is a method to increase low energy beam currents in multiple stages. The Frankfurt Funneling Experiment is a model of such a stage. The experiment is built up of two ion sources with a electrostatic lens systems, a Two-Beam RFQ accelerator, a funneling deflector and a beam diagnostic system. The two beams are bunched and accelerated in a Two-Beam RFQ and the last parts of the RFQ electrodes achieve a 3d focus at the crossing point of the two beam axis. A funneling deflector combines the bunches to a common beam axis. The optimized ion sources are adapted to the front end bunching section. Recent funneling measurements with the one-gap and the multi-gap deflector will be presented.

• M. Vossberg, N. Mueller, A. Schempp
  IAP, Frankfurt am Main
• W.A. Barth, L.A. Dahl
  GSI, Darmstadt

A new CW-RFQ will be built for the upgrade of the HLI (High Charge State Injector) of GSI for operating with a 28 GHz-ECR-Ion source and simultaneous increase of the beam duty cycle from 25% to 100 %. The new HLI 4-rod RFQ will accelerate charged ions from 4 keV/u to 300 keV/u for the injection into the IH-structure The design had been optimized to get a rather short structure with LRFQ=2m to match the available RF-power of max. 60 kW in cw. High beam transmission, a small energy spread and small transverse emittance growth and good input matching were design goals. Properties of this CW-RFQ and status of project will be presented.