Fermilab, Batavia
Muons, Inc, Batavia
CERN, Geneva
Funding: supported in part by USDOE STTR Grant DE-FG02-08ER86350
The great advantage of the helical ionization cooling channel (HCC) is its compact structure that enables the fast cooling of muon beam 6-dimensional phase space. This compact aspect requires a high average RF gradient, with few places that do not have cavities. Also, the muon beam is diffuse and requires an RF system with large transverse and longitudinal acceptance. A traveling wave system can address these requirements. First, the number of RF power coupling ports can be significantly reduced compared with our previous pillbox concept. Secondly, by adding a nose on the cell iris, the presence of thin metal foils traversed by the muons can possibly be avoided. We show simulations of the cooling performance of a traveling wave RF system in a HCC, including cavity geometries with inter-cell RF power couplers needed for power propagation.
FZJ, Jülich
CERN, Geneva
The COoler SYnchrotron COSY at the Forschungszentrum Jülich is operating now since 1992. Up to 5*1010 protons can be delivered over a momentum range of 600 MeV/c to 3.6 GeV/c. The prototype of the HESR barrier bucket cavity was installed into COSY and many measurements have been performed. Especially the co-operation of barrier bucket with stochastic cooling has been studied. During the measurements the internal WASA Pellet target was available which is similar to the PANDA target at the HESR. A 1.2m long cryo-tank has been designed and installed to measure the sensitivities of new pickup structures for the HESR stochastic cooling system. Tank design and structures arrangement correspond to the projected HESR stochastic cooling layout. The recent results will be presented.
FZJ, Jülich
CNS, Saitama
CERN, Geneva
The High Energy Storage Ring (HESR) of the future International Facility for Antiproton and Ion Research (FAIR) at the GSI in Darmstadt will be built as an anti-proton cooler ring in the momentum range from 1.5 to 15 GeV/c. An important and challenging feature of the new facility is the combination of phase space cooled beams with internal targets. In addition to electron cooling transverse and longitudinal stochastic cooling are envisaged to accomplish these goals. A detailed numerical analysis of the Fokker-Planck equation for longitudinal filter and time-of-flight cooling including an internal target and intrabeam scattering has been carried out to demonstrate the stochastic cooling capability. Model predictions have been compared to experimental cooling results with internal targets at the COSY facility. Experimental results at COSY to compensate the large mean energy loss induced by an internal Pellet target similar to that being used by the PANDA experiment at the HESR with a barrier bucket cavity (BB) will be presented. Experimental tests of stochastic filter cooling with internal target and BB operation as well as expected cooling properties for the HESR are discussed.
GSI, Darmstadt
CERN, Geneva
The FAIR storage ring complex comprises three storage rings with a magnetic rigidity of 13 m. Each of the rings, CR, RESR, and NESR, serves specific tasks in the preparation of secondary beams, rare isotopes and antiprotons, or for experiments with heavy ion beams. The CR is optimized for fast stochastic pre-cooling of secondary beams. The RESR design includes optimization of antiproton accumulation. The design of the NESR for experiments with heavy ions, deceleration of ions or antiprotons for a subsequent low energy facility, and the accumulation of rare isotope beams is proceeding. This report summarizes various new concepts conceived in the design process of this new storage ring facility.
