IPAC2011 - List of Authors (Litvinov, S.A.)

Paper	Title	Page
WEPC054	Amplitude Dependent Tune Spread in the CR Operated as an Antiproton Collector	2136
	A. Dolinskii, C. Dimopoulou, O.E. Gorda, S.A. Litvinov, F. Nolden, M. Steck GSI, Darmstadt, Germany
	The Collector Ring is planned to be built for efficient cooling of antiprotons and rare isotopes beams. In order to accept hot antiproton beams coming from a separator large aperture magnets are required. This paper examines the effects which, may influence on the beam dynamic because of both large both betatron amplitude oscillations (240 mm mrad) and momentum spread (6%). Using analytic expressions the amplitude-dependent tune shifts driven by sextupole magnets, fringe field of quadrupole magnets and kinematics effects have been calculated. The results are compared with numerical simulations. Tracking studies for the CR operated as an antiproton collector have been performed considering the real shape of the magnetic field of the wide aperture quadrupole. We report on quantitative studies of the effects on the tune spread and its influence on the beam losses.

WEPC055	Beam Orbit and Power Converter Stability at the CR	2139
	A. Dolinskii, C. Dimopoulou, O.E. Gorda, S.A. Litvinov, F. Nolden, M. Steck, H. Weick GSI, Darmstadt, Germany
	For the isochronous mode operation of the CR with reference to have good properties of the mass measurements we study the sources of the beam orbit fluctuation and as consequence power converter requirements for the CR operated at BR=13 Tm. This papaer presents a summary of the different factors causing beam orbit variation, which leads to reduction of the mass measurements precision. The requirements to the power converters have been addressed.

WEPC056	Beam Test of Slow Extraction from the ESR	2142
	A. Dolinskii, C. Dimopoulou, O.E. Gorda, S.A. Litvinov, F. Nolden, M. Steck GSI, Darmstadt, Germany
	In the frame of a dedicated ESR machine development the conventional third order resonant slow extraction was theoretically investigated and experimentally tested. The possibility to extract a beam from the ESR by preparing a resonant closed orbit, which has strong nonlinear characteristics, was demonstrated. A third-integer resonance slow extraction has been adopted for the 100 MeV/u Ar beam.

WEPC058	Field Properties of the ESR Magnets and their Influence on Beam Optics	2148
	O.E. Gorda, C. Dimopoulou, A. Dolinskii, S.A. Litvinov, F. Nolden, M. Steck GSI, Darmstadt, Germany
	Machine experiments at the experimental storage ring (ESR) demonstrated that the ring acceptance is strongly restricted by field errors. Higher-order field harmonics of the dipole and quadrupole magnets have been calculated and then used in particle tracking simulations in order to find out the dynamic aperture of the ESR. To benchmark the results of numerical calculations, betatron tune measurements have been performed with a uranium beam at the energy of 400 MeV/u. The results of the magnetic field simulations for the ESR magnets and a comparison between the measured and calculated tune behavioгr are presented.

THPS001	Experimental Studies of Beam Loss during Low Energy Operation with Electron Cooled Heavy Ions in the ESR	3424
	P.A. Görgen, O. Boine-Frankenheim TEMF, TU Darmstadt, Darmstadt, Germany S. Appel, C. Dimopoulou, S.A. Litvinov, M. Steck GSI, Darmstadt, Germany
	At the ESR at GSI electron cooled heavy ion beams are decelerated to 4 MeV/u and extracted for the HITRAP experiment. We will report about cooling equilibrium measurements at 4 and 30 MeV/u for Ar¹⁸⁺ coasting beams. We compare the equilibrium beam parameters with results from beam dynamics simulations using the BETACOOL code and an analytic model of reduced complexity. The time slot in which HITRAP accepts beam is 2μs long. For optimum efficiency the beam has to be bunched to this length before extraction. The obtained bunch profiles are compared to longitudinal beam dynamics simulations. Our measurements show that at both energies bunching leads to severe beam loss. The estimated transverse space charge tune shifts during the rf bunching indicate that resonance crossing might be responsible for the observed the beam loss. The influence of the tune shift will be further evaluated through resonance measurements.

Paper

Title

Page

Amplitude Dependent Tune Spread in the CR Operated as an Antiproton Collector

2136

A. Dolinskii, C. Dimopoulou, O.E. Gorda, S.A. Litvinov, F. Nolden, M. Steck
GSI, Darmstadt, Germany

The Collector Ring is planned to be built for efficient cooling of antiprotons and rare isotopes beams. In order to accept hot antiproton beams coming from a separator large aperture magnets are required. This paper examines the effects which, may influence on the beam dynamic because of both large both betatron amplitude oscillations (240 mm mrad) and momentum spread (6%). Using analytic expressions the amplitude-dependent tune shifts driven by sextupole magnets, fringe field of quadrupole magnets and kinematics effects have been calculated. The results are compared with numerical simulations. Tracking studies for the CR operated as an antiproton collector have been performed considering the real shape of the magnetic field of the wide aperture quadrupole. We report on quantitative studies of the effects on the tune spread and its influence on the beam losses.

WEPC055

Beam Orbit and Power Converter Stability at the CR

2139

A. Dolinskii, C. Dimopoulou, O.E. Gorda, S.A. Litvinov, F. Nolden, M. Steck, H. Weick
GSI, Darmstadt, Germany

For the isochronous mode operation of the CR with reference to have good properties of the mass measurements we study the sources of the beam orbit fluctuation and as consequence power converter requirements for the CR operated at BR=13 Tm. This papaer presents a summary of the different factors causing beam orbit variation, which leads to reduction of the mass measurements precision. The requirements to the power converters have been addressed.

WEPC056

Beam Test of Slow Extraction from the ESR

2142

A. Dolinskii, C. Dimopoulou, O.E. Gorda, S.A. Litvinov, F. Nolden, M. Steck
GSI, Darmstadt, Germany

In the frame of a dedicated ESR machine development the conventional third order resonant slow extraction was theoretically investigated and experimentally tested. The possibility to extract a beam from the ESR by preparing a resonant closed orbit, which has strong nonlinear characteristics, was demonstrated. A third-integer resonance slow extraction has been adopted for the 100 MeV/u Ar beam.

WEPC058

Field Properties of the ESR Magnets and their Influence on Beam Optics

2148

O.E. Gorda, C. Dimopoulou, A. Dolinskii, S.A. Litvinov, F. Nolden, M. Steck
GSI, Darmstadt, Germany

Machine experiments at the experimental storage ring (ESR) demonstrated that the ring acceptance is strongly restricted by field errors. Higher-order field harmonics of the dipole and quadrupole magnets have been calculated and then used in particle tracking simulations in order to find out the dynamic aperture of the ESR. To benchmark the results of numerical calculations, betatron tune measurements have been performed with a uranium beam at the energy of 400 MeV/u. The results of the magnetic field simulations for the ESR magnets and a comparison between the measured and calculated tune behavioгr are presented.

THPS001

Experimental Studies of Beam Loss during Low Energy Operation with Electron Cooled Heavy Ions in the ESR

3424

P.A. Görgen, O. Boine-Frankenheim
TEMF, TU Darmstadt, Darmstadt, Germany
S. Appel, C. Dimopoulou, S.A. Litvinov, M. Steck
GSI, Darmstadt, Germany

At the ESR at GSI electron cooled heavy ion beams are decelerated to 4 MeV/u and extracted for the HITRAP experiment. We will report about cooling equilibrium measurements at 4 and 30 MeV/u for Ar¹⁸⁺ coasting beams. We compare the equilibrium beam parameters with results from beam dynamics simulations using the BETACOOL code and an analytic model of reduced complexity. The time slot in which HITRAP accepts beam is 2μs long. For optimum efficiency the beam has to be bunched to this length before extraction. The obtained bunch profiles are compared to longitudinal beam dynamics simulations. Our measurements show that at both energies bunching leads to severe beam loss. The estimated transverse space charge tune shifts during the rf bunching indicate that resonance crossing might be responsible for the observed the beam loss. The influence of the tune shift will be further evaluated through resonance measurements.