| Paper |
Title |
Other Keywords |
Page |
| TUA1I02 |
Theoretical Study of Emittance Transfer
|
emittance, coupling, electron, simulation |
82 |
| |
- H. Okamoto
Hiroshima University, Higashi-Hiroshima
- K. Kaneta
HU/AdSM, Higashi-Hiroshima
- A. Sessler
LBNL, Berkeley, California
| |
Funding: Work supported in part by the U. S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-AC02-05CH11231.
Liouville's theorem implies that the six-dimensional phase-space volume occupied by a charged-particle beam is an approximate invariant unless the beam is subjected to dissipative interactions (such as in cooling). Symplectic conditions, in a Hamiltonian system (once again, no dissipation), put constraints upon emittance transfer between the various degrees of freedom. [1] We can, however, even in non-dissipative Hamiltonian systems arrange for partial emittance transfers. This process results in phase space correlations and change in the emittance projections on to various phase planes; namely, the projected emittances in three degrees of freedom are controllable while the direction and amount of a possible emittance flow are not very flexible because of the symplectic nature of Hamiltonian system. In some applications, it is clearly advantageous to optimize the ratios of projected emittances despite the effect of correlations. Since the three emittances are not always equally important, we may consider reducing the emittance of one direction at the sacrifice of the other emittance(s). As a possible scheme to achieve such emittance control, we study a compact storage ring operating near resonance. The basic features of linear and nonlinear emittance flow are briefly discussed with numerical examples. A general discussion touching on some of these matters has been previously presented. [2]
[1] E. D. Courant, Perspectives in Modern Physics, edit R. E. Marshak (1966).[2] H. Okamoto, K. Kaneta and A. M. Sessler, to be published in J. Phys. Soc. Jpn.
|
|
|
Slides
|
|
|
|
| WEM1C03 |
Analysis of Resonances Induced by the SIS-18 Electron Cooler
|
electron, space-charge, emittance, lattice |
121 |
| |
- S. Sorge, O. Boine-Frankenheim, G. Franchetti
GSI, Darmstadt
| |
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.
|
|
|
|
Slides
|
|
|
|
| THAP15 |
Beam Based Measurements for Stochastic Cooling Systems at Fermilab
|
antiproton, pick-up, accumulation, lattice |
198 |
| |
- V. A. Lebedev, R. J. Pasquinelli, S. J. Werkema
Fermilab, Batavia, Illinois
| |
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.
|
|
|
Poster
|
|
|
|