HB2016 - List of Keywords (focusing)

Paper	Title	Other Keywords	Page
MOPL004	Beam Dynamics Simulations and Code Comparison for a New CW RFQ Design	rfq, linac, simulation, space-charge	188
	S.M. Polozov, W.A. Barth, T. Kulevoy, S. Yaramyshev MEPhI, Moscow, Russia W.A. Barth, S. Yaramyshev GSI, Darmstadt, Germany W.A. Barth HIM, Mainz, Germany T. Kulevoy ITEP, Moscow, Russia
	Research and development of CW applications is an important step in RFQ design. The RF potential should be limited by 1.3-1.5 of Kilpatrick criterion for the CW mode. A 2 MeV RFQ is under development for the compact CW research proton accelerator, as well as for planned driver linac* in Russia. The maximum beam current is fixed to10 mA; the operating frequency has been set to 162 MHz. The new RFQ linac design will be presented and beam dynamics simulation results will be discussed. Calculations of beam dynamics are provided using the codes BEAMDULAC (developed at MEPhI for linac design) and DYNAMION. A comparison of the software performance is presented. * A.Y. Aksentyev, T.V. Kulevoy, S.M. Polozov. Proc. of IPAC’14, pp. 3286-3288.
	Poster MOPL004 [2.609 MB]
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THPM1X01	Typology of Space Charge Resonances	resonance, space-charge, emittance, lattice	486
	I. Hofmann GSI, Darmstadt, Germany
	The existence of structural space charge resonant effects in otherwise linear periodic focusing systems is well-known, but referred to in a variety of languages and contexts. We show here that for short bunched beams a ‘‘classification'' in two major groups is possible, e.g. parametric resonances or instabilities on the one hand and single particle type space charge resonances on the other hand. The primary feature of distinction is that for the former the driving space charge force initially exists on the noise level (rms or higher order mismatch) only and gets amplified parametrically, hence an entirely coherent response; for the latter the driving space charge multipole is part of the initial density profile and the coherent response is weak. In the extreme limit of KV beams only parametric resonances (instabilities) exist, and in principle in all orders. For waterbag or Gaussian distributions we find half-integer parametric resonances only up to fourth order, but evidence for single particle resonances in all orders up to tenth have been identified.
	Slides THPM1X01 [3.094 MB]
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THPM5X01	Using an Electron Cooler for Space Charge Compensation in the GSI Synchrotron SIS18	electron, ion, space-charge, experiment	496
	W.D. Stem, O. Boine-Frankenheim TEMF, TU Darmstadt, Darmstadt, Germany O. Boine-Frankenheim GSI, Darmstadt, Germany
	Funding: Work is supported by BMBF contract FKZ:05P15RDRBA For the future operation of the SIS18 as a booster synchrotron for the FAIR SIS100, space charge and beam lifetime are expected to be the main intensity limitations. Intensity is limited in part by the space-charge-induced incoherent tune shift in bunched beams. A co-propagating, low energy electron lens can compensate for this tune shift by applying opposing space-charge fields in the ion beam. In this paper, we study the effect of using the existing electron cooler at the SIS18 as a space charge compensation device. We anticipate beta beating may arise due to the singular localized focusing error, and explore the possibility of adding additional lenses to reduce this error. We also study the effect of electron lenses on the coherent (collective) and incoherent (single-particle) stopbands. Furthermore, we estimate the lifetime of partially stripped heavy-ions due to charge exchange process in the lens.
	Slides THPM5X01 [4.731 MB]
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Paper

Title

Other Keywords

Page

MOPL004

Beam Dynamics Simulations and Code Comparison for a New CW RFQ Design

rfq, linac, simulation, space-charge

188

S.M. Polozov, W.A. Barth, T. Kulevoy, S. Yaramyshev
MEPhI, Moscow, Russia
W.A. Barth, S. Yaramyshev
GSI, Darmstadt, Germany
W.A. Barth
HIM, Mainz, Germany
T. Kulevoy
ITEP, Moscow, Russia

Research and development of CW applications is an important step in RFQ design. The RF potential should be limited by 1.3-1.5 of Kilpatrick criterion for the CW mode. A 2 MeV RFQ is under development for the compact CW research proton accelerator, as well as for planned driver linac* in Russia. The maximum beam current is fixed to10 mA; the operating frequency has been set to 162 MHz. The new RFQ linac design will be presented and beam dynamics simulation results will be discussed. Calculations of beam dynamics are provided using the codes BEAMDULAC (developed at MEPhI for linac design) and DYNAMION. A comparison of the software performance is presented.
* A.Y. Aksentyev, T.V. Kulevoy, S.M. Polozov. Proc. of IPAC’14, pp. 3286-3288.

Poster MOPL004 [2.609 MB]

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THPM1X01

Typology of Space Charge Resonances

resonance, space-charge, emittance, lattice

486

I. Hofmann
GSI, Darmstadt, Germany

The existence of structural space charge resonant effects in otherwise linear periodic focusing systems is well-known, but referred to in a variety of languages and contexts. We show here that for short bunched beams a ‘‘classification'' in two major groups is possible, e.g. parametric resonances or instabilities on the one hand and single particle type space charge resonances on the other hand. The primary feature of distinction is that for the former the driving space charge force initially exists on the noise level (rms or higher order mismatch) only and gets amplified parametrically, hence an entirely coherent response; for the latter the driving space charge multipole is part of the initial density profile and the coherent response is weak. In the extreme limit of KV beams only parametric resonances (instabilities) exist, and in principle in all orders. For waterbag or Gaussian distributions we find half-integer parametric resonances only up to fourth order, but evidence for single particle resonances in all orders up to tenth have been identified.

Slides THPM1X01 [3.094 MB]

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THPM5X01

Using an Electron Cooler for Space Charge Compensation in the GSI Synchrotron SIS18

electron, ion, space-charge, experiment

496

W.D. Stem, O. Boine-Frankenheim
TEMF, TU Darmstadt, Darmstadt, Germany
O. Boine-Frankenheim
GSI, Darmstadt, Germany

Funding: Work is supported by BMBF contract FKZ:05P15RDRBA
For the future operation of the SIS18 as a booster synchrotron for the FAIR SIS100, space charge and beam lifetime are expected to be the main intensity limitations. Intensity is limited in part by the space-charge-induced incoherent tune shift in bunched beams. A co-propagating, low energy electron lens can compensate for this tune shift by applying opposing space-charge fields in the ion beam. In this paper, we study the effect of using the existing electron cooler at the SIS18 as a space charge compensation device. We anticipate beta beating may arise due to the singular localized focusing error, and explore the possibility of adding additional lenses to reduce this error. We also study the effect of electron lenses on the coherent (collective) and incoherent (single-particle) stopbands. Furthermore, we estimate the lifetime of partially stripped heavy-ions due to charge exchange process in the lens.

Slides THPM5X01 [4.731 MB]

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reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)