• H. Soltner, U. Bechstedt, R. Tölle
  FZJ, Jülich
• J.G. De Villiers
  iThemba LABS, Somerset West

Funding: Work supported by BMBF and NRF, Project code SUA 06/003

Forschungszentrum Jülich has taken the leadership of a consortium responsible for the design, installation and commissioning of the High-Energy Storage Ring (HESR) for antiprotons as part of the FAIR project at GSI in Darmstadt, Germany. Since a normal-conducting design of the ring has now been favored over the previously envisioned superconducting option, new calculations have been performed in order to assess the magnetic field characteristics of the normal-conducting dipole, quadrupole, and sextupole magnets of the HESR. This paper presents the physical features of the magnets and the results of the 3D calculations with emphasis on the various multipole contributions at the ends of the magnets.

• E.N. Zaplatin, R. Maier, M. Pap, R. Stassen, R. Tölle
  FZJ, Jülich
• W. Behr, H. Glueckler, W. Guenther, J. Wolters
  Forschungszentrum Jülich GmbH, Institut fur Nuklearchemie (INC), Jülich

The paper describes the design, fabrication and first test results of the triple-spoke cavity (resonant frequency 352 MHz, beta=0.48) developed at Forschungszentrum Jülich in the frame of High Intensity Pulsed Proton Injector project. The cavity has 5 cm diameter beam aperture, a transverse radius of 21.7 cm and the whole length of 78 cm. An initial wall thickness of niobium sheets used for cavity fabrication was around 4 mm. The RF cavity design has been adapted to two main goals - the simplest technology of cavity manufacture and for the prime goal of the project to achieve the best possible structural parameters (Lorenz force frequency shift and a resonant frequency pressure dependence). Intense cavity structural analyses have been conducted and the further prospectives on cavity developments are also presented. Construction of the niobium cavity prototype has been completed, the cavity has been chemically processed. Results of initial cold test are discussed.