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| TUM2I06 |
Cooling Scheme for a Muon Collider
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collider, simulation, emittance, proton |
77 |
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| TUA1I04 |
High-Energy Colliding Crystals – A Theoretical Study
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ion, collider, luminosity, simulation |
91 |
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- J. Wei
BNL, Upton, Long Island, New York
- H. Okamoto
Hiroshima University, Higashi-Hiroshima
- A. Sessler
LBNL, Berkeley, California
- H. Sugimoto, Y. Yuri
HU/AdSM, Higashi-Hiroshima
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Funding: * Work performed under the auspices of the U. S. Department of Energy.
Recent theoretical investigations of beam crystallization mainly use computer modeling based on the method of molecular dynamics (MD) and analytical study based on phonon theory [1]. Topics of investigation include crystal stability in various accelerator lattices under different beam conditions, colliding crystalline beams [2], and crystalline beam formation in shear-free ring lattices with both magnets and electrodes [3]. In this paper, we review the above mentioned theoretical studies and, in particular, discuss the development of the phonon theory in a time-dependent Hamiltonian system representing a storage ring of AG focusing. Analytical study of crystalline beam stability in an AG-focusing ring was previously limited to the smooth approximation. In a typical ring, analytical results obtained under such approximation largely agrees with the results obtained with the molecular dynamics (MD) simulation method. However, as we explore ring lattices appropriate for beam crystallization at high energies (Lorentz factor gamma much higher than the betatron tunes) [2,4], this approximation fails. Here, we present a newly developed formalism to exactly predict the stability of a 1-dimensional crystalline beam in an AG focusing ring lattice.
[1] X.-P. Li, et al, PR ST-AB, 9, 034201 (2006). [2] J. Wei, A. M. Sessler, EPAC, 862 (1998)[3] M. Ikegami, et al, PR ST-AB 7, 120101 (2004).[4] J. Wei, H. Okamoto, et al, EPAC 2006.
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Slides
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| TUA2C05 |
Introduction to the Session on Lattice Optimization for Stochastic Cooling
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quadrupole, pick-up, kicker, betatron |
96 |
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| TUA2C06 |
A Split-Function Lattice for Stochastic Cooling
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pick-up, kicker, proton, dipole |
99 |
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- J. Wei
BNL, Upton, Long Island, New York
- S. Wang
IHEP Beijing, Beijing
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Funding: * Work performed under the auspices of the US Department of Energy.
During the EPAC 2006 we reported the lattice design for rapid-cycling synchrotrons used to accelerate high-intensity proton beams to energy of tens of GeV for secondary beam production. After primary beam collision with a target, the secondary beam can be collected, cooled, accelerated or decelerated by ancillary synchrotrons for various applications. For the main synchrotron, the lattice has: - flexible momentum compaction to avoid transition and to facilitate RF gymnastics
- long straight sections for low-loss injection, extraction, and high-efficiency collimation
- dispersion-free straights to avoid longitudinal-transverse coupling, and
- momentum cleaning at locations of large dispersion with missing dipoles.
Then, we present a lattice for a cooler ring for the secondary beam. The momentum compaction across half of this ring is near zero, while for the other half it is normal. Thus, bad mixing is minimized while good mixing is maintained for stochastic beam cooling.
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Slides
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| TUA2C07 |
Advanced HESR Lattice with Non-Similar Arcs for Improved Stochastic Cooling
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quadrupole, pick-up, kicker, dynamic-aperture |
102 |
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- Y. Senichev
FZJ, Jülich
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Optimized stochastic cooling requires special ion optical conditions in a storage ring. The frequency slip factor strongly influences the mixing factor, and strong requirements have to be fulfilled by the unwanted mixing of the path from pickup to kicker and the wanted mixing on the way from kicker to pickup. Several ideas for a lattice with "irregular" momentum compaction factor have been investigated. The influence of possible lattice modifications to the stochastic cooling performance for COSY will be discussed. Investigations of a lattice optimized for the stochastic cooling in HESR will be summarized.
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Slides
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| TUA2C08 |
Lattice Considerations for the Collector and the Accumulator Rings of the FAIR Project
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antiproton, pick-up, injection, kicker |
106 |
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- A. Dolinskii, F. Nolden, M. Steck
GSI, Darmstadt
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Two storage rings (Collector Ring (CR) and Recycled Experimental Storage Ring (RESR)) have been designed for efficient cooling, accumulation and deceleration of antiproton and rare isotopes beams. The large acceptance CR must provide efficient stochastic cooling of hot radioactive ions as well as antiproton beams. The RESR will be used as an accumulator of high intensity antiproton beams and a decelerator of rare isotopes. Different lattice structures have been considered in order to achieve good properties for the stochastic cooling and at the same time the maximum dynamic aperture. The structure of the ring lattices and its ion optical properties are described in this contribution. The beam dynamics stability and flexibility for operation in different modes are discussed.
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Slides
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| TUA2C09 |
Lattice Optimization for the Stochastic Cooling in the Accumulator Ring at Fermilab
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antiproton, emittance, kicker, optics |
110 |
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- V. P. Nagaslaev, V. A. Lebedev, S. J. Werkema
Fermilab, Batavia, Illinois
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New efforts are under way at Fermilab to increase the rate of the antiproton production. This program includes the machine optics optimization in order to improve mixing and help stochastic cooling. The new lattice has been implemented in May of this year. Results will be discussed, as well as some aspects of model development and lattice measurements.
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Slides
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| WEM1C02 |
Optical Stochastic Cooling Experiment at the MIT-Bates South Hall Ring
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electron, undulator, radiation, damping |
117 |
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- W. A. Franklin, K. A. Dow, J. P. Hays-Wehle, F. X. Kaertner, R. Milner, R. P. Redwine, A. M. Siddiqui, C. Tschalaer, E. Tsentalovich, D. Wang, F. Wang, J. van der Laan
MIT, Middleton, Massachusetts
- M. Bai, M. Blaskiewicz, W. Fischer, B. Podobedov, V. Yakimenko
BNL, Upton, Long Island, New York
- W. A. Barletta, A. Zholents, M. S. Zolotorev
LBNL, Berkeley, California
- S.-Y. Lee
IUCF, Bloomington, Indiana
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An experiment to demonstrate for the first time the principle of optical stochastic cooling* has been proposed using electrons at 300 MeV in the MIT-Bates South Hall Ring. The experiment will operate the Ring in a dedicated mode using a lattice tailored for transverse and longitudinal cooling. The experimental apparatus, including a magnetic chicane, undulator system, and ultrafast optical amplifier, has been designed to be compatible with existing technology. The experiment will study OSC physics to evaluate its prospects for future application at the high energy high brightness frontier and to develop deterministic diagnostics needed to achieve it. Details of the experiment design will be presented along with results from an initial beam feasibility study.
*M. Zolotorev and A. Zholents, Phys. Rev. E 50, 3087 (1994)
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Slides
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| WEM1C03 |
Analysis of Resonances Induced by the SIS-18 Electron Cooler
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resonance, electron, space-charge, emittance |
121 |
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- S. Sorge, O. Boine-Frankenheim, G. Franchetti
GSI, Darmstadt
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Due to the requirements concerning the quality of the particle beams in the FAIR project, i.e. a small momentum uncertainty together with high currents and, in the case of the storage rings, particle target interaction, there will be a strong need of electron cooling. On the other hand, an electron cooler acts as a non-linear optical element besides electron cooling. This may lead to the excitation of resonances possibly resulting in an increase of the emittance. The aim of this work is the calculation of resonances driven by the electron cooler in the Schwerionensynchrotron (SIS) 18 being a present device at GSI Darmstadt having an electron cooler. So, we get the opportunity to prove our results experimentally. For our calculations, we used a model system consisting of a rotation matrix representing the lattice and giving the according phase advance, and a non-linear transverse momentum kick representing the electron cooler in thin lens approximation. Proceeding in this way, we got only the resonances driven by the cooler. Furthermore, we used the MAD-X code to perform our calculations.
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Slides
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| THM1I01 |
Commissioning and Performance of LEIR
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ion, injection, linac, vacuum |
134 |
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- C. Carli
CERN, Geneva
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The Low Energy Ion Ring (LEIR) is a key element of the LHC ion injector chain. Under fast electron cooling, several long pulses from the ion Linac 3 are accumulated and cooled, and transformed into short bunches with a density sufficient for the needs of the LHC. Experience from LEIR commissioning and the first runs in autumn 2006 and summer 2007 to provide the so-called "early LHC ion beam" for setting-up in the PS and the SPS will be reported. Studies in view of the beam needed for nominal LHC ion operation are carried out in parallel to operation with lower priority.
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Slides
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| THAP15 |
Beam Based Measurements for Stochastic Cooling Systems at Fermilab
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antiproton, pick-up, resonance, accumulation |
198 |
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- V. A. Lebedev, R. J. Pasquinelli, S. J. Werkema
Fermilab, Batavia, Illinois
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Maximizing performance of stochastic cooling would not be possible without beam based measurements. In this paper we discuss experience with beam based measurements of Antiproton source stochastic cooling; and how the measurement results are used in building of the cooling system model.
Work supported by the Fermi Research Alliance, under contract DE-AC02-76CH03000 with the U. S. Dept. of Energy.
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Poster
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