Results 1 - 10 of 1991
Results 1 - 10 of 1991. Search took: 0.045 seconds
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[en] Three storage rings with a maximum magnetic rigidity of 13 Tm are foreseen as part of the FAIR project. They will mainly serve the preparation of intense secondary beams of antiprotons and rare isotopes, which are produced with high intensity proton and heavy ion beams, respectively. Cooling, by stochastic and electron cooling, and accumulation as well as deceleration of the secondary beams are manipulation techniques which are foreseen. Internal targets and collisions of rare isotope beams with electrons or antiprotons in a collider set-up will be employed in physics experiments studying the properties of the secondary beams. This report summarizes the latest design work for the FAIR storage rings. (author)
[en] Testing a single hardware unit of an accelerator control system often requires the setup of a program with graphical user interface. Developing a dedicated application for a specific hardware unit test could be time consuming and the application may become obsolete after the unit tests. This paper documents a methodology for quick design and setup of an interface focused on performing unit tests of accelerator equipment with minimum programming work. The method has three components. The first is a generic accelerator device object (ADO) manager which can be used to setup, store, and log testing controls parameters for any unit testing system. The second involves the design of a TAPE (Tool for Automated Procedure Execution) sequence file that specifies and implements all te testing and control logic. The sting third is the design of a PET (parameter editing tool) page that provides the unit tester with all the necessary control parameters required for testing. This approach has been used for testing the horizontal plane of the Stochastic Cooling Motion Control System at RHIC.
[en] Electron cooling together with intra-beam scattering results in a transverse distribution that can best be described by a sum of two gaussians, one for the high-density core and one for the tails of the distribution. Simulation studies are being performed to understand the beam-beam interaction of these double-gaussian beams. Here we report the effect of loW--frequency random tune modulations on diffusion in double-gaussian beams and compare the effects to those in beam-beam interactions with regular gaussian beams and identical tune shift parameters
[en] Investigation results of the effect of electron cooling are considered. The current state-of-the-art is analyzed. The possibilities are discussed for the experimental study of the electron cooling phenomenon using a large shock tube and plasma-gas-dynamic stand at the Ioffe Institute.
[en] The beam was successfully stored in the TARN II ring by an injection method using the third order resonance. Beam intensity obtained by the resonance injection is comparable with that by the multiturn injection. A new stacking method utilizing the resonance injection and the electron cooling is introduced
[en] The beam cooling equilibrium with internal target interaction is analyzed for parameters relevant to the proposed High Energy Storage Ring (HESR). For the proposed experiments with anti-protons high luminosities together with low momentum spreads are required. Rate equations are used to predict the rms equilibrium beam parameters. The cooling and IBS rate coefficients are obtained from simplified models. Energy loss straggling in the target and the associated beam loss are analyzed analytically assuming a thin target. A longitudinal kinetic simulation code is used to study the evolution of the momentum distribution in coasting and bunched beams. Analytic expressions for the target induced momentum tail are found in good agreement with the simulation results
[en] A five-cell high current superconducting cavity for the electron cooling project at RHIC is under fabrication. Higher order modes (HOMs), one of main limiting factors for high current energy-recovery operation, are under investigation. Calculations of HOMs using time-domain methods in Mafia will be discussed and compared to calculations in the frequency domain. Beam breakup thresholds determined from numerical codes for the five-cell cavity will be presented. A possible motivation towards a 2 x 2 superstructure using the current five-cell design will also be discussed
[en] The first electron cooling system for LEAR will cover the momentum range between 100 and 600 MeV/c. Recently, the assembly of a new vacuum system with modified electron gun and collector from the Initial Cooling Experiment (ICE) has been finished. In the present configuration, gun and collector allow for cooling antiprotons at momenta up to 370 MeV/c. A new gun and collector for the higher momenta are being designed. After separate tests in 1985, the cooler will be ready for installation at the end of this year. In this report, we will describe the cooling device and its performance expected after the installation
[en] This paper describes a type of notch filter and demonstrates the advantages of this filter in providing small notch dispersion and other properties necessary for stochastic cooling systems. A comparative evaluation is made of the advantages between the shorted stub filter and the basic correlator filter. Schematic and phasor diagrams of the basic correlator filter are shown. A description of the BCF system is also given
[en] The High-Energy Storage Ring (HESR) of the future International Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt is planned as an antiproton storage ring in the momentum range from 1.5 to 15 GeV/c. The HESR is being designed and built by a consortium consisting of IKP at Forschungszentrum Juelich, TSL at Uppsala University, and GSI Darmstadt. An important feature of this new facility is the combination of phase-space cooled beams and thick internal targets (e.g. pellet targets) which results in demanding beam parameter requirements for two operation modes: high luminosity mode with peak luminosities of up to 2 · 1032cm-2s-1 and high resolution mode with a relative momentum spread in the order of a few times 10-5. To reach these beam parameters one needs a very powerful phase-space cooling utilizing high-energy electron cooling and high-bandwidth stochastic cooling. In this paper different beam dynamics issues like closed orbit correction, performance of cooled beams interacting with internal targets and luminosity considerations are discussed. (author)