• P. Gerhard, W.A. Barth, L.A. Dahl, A. Orzhekhovskaya, K. Tinschert, W. Vinzenz, H. Vormann, S.G. Yaramyshev
  GSI, Darmstadt
• A. Schempp, M. Vossberg
  IAP, Frankfurt am Main

The super heavy element research is one of the outstanding projects at GSI. At SHIP* six new elements have been discovered; moreover, nuclear chemical experiments with transactinides were recently performed at TASCA**. This experimental program strongly benefits from high average beam intensities. In the past beam currents were raised significantly by a number of improvements. The present upgrade program comprises the installation of a superconducting (sc) 28 GHz ECR ion source, a new frontend (low energy beam transport and RFQ), and, in the long term, an sc cw Linac. For the short term, the new RFQ will raise the duty factor by a factor of two (50%), limited by the following accelerator only. This bottleneck will be resolved by the applied cw Linac. Beam tests with a newly developed sc CH cavity are scheduled for 2012. The setup of the RFQ as the major upgrade of the 20 year old HLI*** is in progress, the commissioning will be finished in March 2010. Besides a higher duty factor, improved longitudinal beam quality and transmission are expected. This paper reports on the challenging rf and beam commissioning.

* Separator for Heavy Ion Reaction Products
** TransActinide Separator and Chemistry Apparatus
*** High charge state injector, a part the UNILAC

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

Abstract 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. HF-Simulations with CST Microwave Studio and measurements were done. Conditioning of the facility with 20 kW/m and simulations of thermal effects with ALGOR are on focus now. First results and the status of the project will be presented.

• N. Mueller, M. Baschke, J.M. Maus, 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. The end section of the RFQ electrodes are designed to achieve a 3d focus at the crossing point of the two beam axis. New simulations with the RFQSIM-Code for a matching system with extended electrodes will be presented.

• N. Mueller, U. Bartz, M. Baschke, A. Schempp, J.S. Schmidt
  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 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. A funneling deflector combines the bunches to a common beam axis. Current work is beam tests with the new beam matching section. First funneling beam and energy measurements with the improved Two-Beam-RFQ will be presented.

• J.S. Schmidt, J.M. Maus, N. Mueller, A. Schempp
  IAP, Frankfurt am Main
• J. Haeuser
  Kress GmbH, Biebergemuend
• O.K. Kester
  NSCL, East Lansing, Michigan

A new reaccelerator facility ReA3 is currently under construction for National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU). As part of that project a new 3.5 m long 4-rod Radio Frequency Quadrupole (RFQ) has been build. This RFQ accelerates ions with a Q/A ratio of 0.2 up to 0.5 from an input energy of 12 keV/u to the final energy of 600 keV/u. We have designed the 80.5 MHz-RFQ with a square cavity cross section. It was build and tuned in Frankfurt and has been delivered to MSU. The design and the tuning process of the ReA3-RFQ will be discribed in this paper.

• P.L. Till, P. Kolb, A. Schempp, J.S. Schmidt, M. Vossberg
  IAP, Frankfurt am Main

Buncher-cavities re-accelerate, bunch or re-bunch particle beams. A special form of these buncher-rf-cavities is a spiral-structure. Two different spiral resonators were simulated and build for the new EBIS LINAC at Brookhaven National Laboratory. These buncher-cavities have a remarkably large aperture of 100 mm. To optimize the cavities to the BNL-frequency of 100 MHz, simulations have been carried out. The impact of changing the gap width, drifttube-, and spiral arm-length on the design of the spiral cavities, has been analyzed. Results of simulations and measurement will be presented.

• U. Ratzinger, L.P. Chau, H. Dinter, M. Droba, M. Heilmann, N.S. Joshi, O. Meusel, I. Müller, D. Mäder, Y.C. Nie, D. Noll, H. Podlech, H. Reichau, A. Schempp, S. Schmidt, K. Volk, C. Wagner, C. Wiesner
  IAP, Frankfurt am Main
• R. Reifarth
  IKF, Frankfurt-am-Main

An intense 2 MeV, 200 mA proton beam will drive a neutron source by the reaction Li7(p,n)Be7 on solid as well as on liquid lithium targets. Actually, the facility is under construction at the physics faculty new experimental hall in Frankfurt. To study in detail the burning of elements in stars by the s-process, a pulsed beam operation with a bunch compressor at the linac exit will offer several Ampere beam current within 1 ns pulse length and with 250 kHz rep. rate at the n - production target. As the upper limit of generated neutrons and the total n- flux at this source are well defined the sample for neutron capture measurements can be placed after a time of flight path as short as 0.8 m only. This will provide highest accessible pulsed neutron flux rates for neutron energies in the 1 - 500 keV range. The highly space charge dominated bunch forming process as well as the ion source, the rf coupled 175 MHz RFQ/DTL - resonator and the target development will be explained.