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Title |
Page |
| WEO4AB01 |
Radio Frequency Quadrupole for Landau Damping in Accelerators. Analytical and numerical studies. |
315 |
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- A. Grudiev, K.S.B. Li
CERN, Geneva, Switzerland
- M. Schenk
LHEP, Bern, Switzerland
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It is proposed to use a radio frequency quadrupole (RFQ) to introduce a longitudinal spread of the betatron frequency for Landau damping of transverse beam instabilities in circular accelerators. The existing theory of stability diagrams for Landau damping is applied to the case of an RFQ. As an example, the required quadrupolar strength is calculated for stabilizing the Large Hadron Collider (LHC) beams at 7 TeV. It is shown that this strength can be provided by a superconducting RF device which is only a few meters long. Furthermore, the stabilizing effect of such a device is proven numerically by means of the PyHEADTAIL macroparticle tracking code for the case of a slow head-tail instability observed in the LHC at 3.5 TeV.
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Slides WEO4AB01 [1.991 MB]
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| WEO4AB02 |
New PSB H− Injection and 2 GeV Transfer to the CERN PS |
320 |
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- W. Bartmann, J.L. Abelleira, B. Balhan, E. Benedetto, J. Borburgh, C. Bracco, C. Carli, G.P. Di Giovanni, V. Forte, S.S. Gilardoni, B. Goddard, G. Gräwer, K. Hanke, M. Hourican, A. Huschauer, M. Meddahi, B. Mikulec, G. Rumolo, L. Sermeus, R. Steerenberg, G. Sterbini, Z. Szoke, R. Wasef, Y. Wei, W.J.M. Weterings
CERN, Geneva, Switzerland
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At CERN Linac4 is being commissioned as first step in the LHC injector upgrade to provide 160 MeV H− ions. In order to fully deploy its potential, the PSB conventional multiturn injection will be replaced by a charge exchange injection. An expected brightness improvement of about a factor 2 would then be difficult to digest at PS injection due to space charge. Therefore the transfer energy between PSB and PS will be increased at the same time from 1.4 to 2 GeV. This paper describes the new PSB injection system and the status of its test stand. Modifications of the PSB extraction and recombination septa and kickers in the transfer line are shown. A new focussing structure for the transfer lines to match the horizontal dispersion at PS injection and the design of a new eddy current septum for the PS injection are presented.
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Slides WEO4AB02 [2.867 MB]
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WEO4AB03 |
Study on the Beam Distribution and Painting Range during the Injection Process for CSNS/RCS |
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- M.Y. Huang, N. Huang, J. Qiu, S. Wang
IHEP, Beijing, People's Republic of China
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Funding: Work supported by National Natural Science Foundation of China (11205185, 11175020, 11175193)
In this paper, firstly, we studied the beam distribution during the injection process for the Rapid Cycling Synchrotron of the China Spallation Neutron Source (CSNS/RCS). The injection processes with and without the space charge were both simulated by the code ORBIT, and the beam distribution of each turn can be obtained. Then, the particle motion during the injection process can be studied and the beam aperture which was required can be obtained. Secondly, the injection processes for different transverse phase space painting ranges were discussed and simulated. Then, the optimized painting range for CSNS/RCS can be obtained.
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Slides WEO4AB03 [0.977 MB]
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