IPAC2021 - List of Authors (Ondreka, D.)

Paper	Title	Page
MOPAB175	Advanced Concepts and Technologies for Heavy Ion Synchrotrons	594
	P.J. Spiller, O. Boine-Frankenheim, L.H.J. Bozyk, S. Klammes, H. Kollmus, D. Ondreka, I. Pongrac, N. Pyka, C. Roux, K. Sugita, St. Wilfert, T. Winkler, D.F.A. Winters GSI, Darmstadt, Germany
	New concepts and technologies are developed to advance the performance of heavy ion synchrotrons. Besides fast ramping of superconducting magnets, extreme UHV technologies to stabilize dynamic vacuum and charge related loss, broad band MA cavities, space charge compensation by means of electron lenses and new cooling technologies, e.g. laser cooling, show great promise to advance the forefront of beam parameters. Several of these technologies and concepts are developed and tested at GSI/FAIR. Progress and plans will be reported.
	Poster MOPAB175 [1.367 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB175
About •	paper received ※ 11 May 2021 paper accepted ※ 21 May 2021 issue date ※ 20 August 2021
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TUPAB200	Status of the Electron Lens for Space Charge Compensation in SIS18	1880
	K. Schulte-Urlichs, S. Artikova, D. Ondreka, P.J. Spiller GSI, Darmstadt, Germany P. Apse-Apsitis, I. Steiks Riga Technical University, Riga, Latvia M. Droba, O. Meusel, H. Podlech, K.I. Thoma IAP, Frankfurt am Main, Germany
	At GSI a project has been initiated to investigate the option of space charge compensation (SCC) by use of an electron lens in order to overcome space charge (SC) limits in the synchrotrons SIS18 and SIS100 for the Facility for Antiproton and Ion Research (FAIR). The repeated crossing of resonance lines due to the synchrotron motion in bunched beams is considered one of the main drivers of SC induced beam loss in the synchrotrons. Electron lenses provide a compensation of ion beam SC by virtue of their negative charge interacting with the ions in the overlap region while a time-varying compensation can be achieved by the modulation of the electron beam. In order to demonstrate space charge compensation of bunched ion beams, an electron lens is under development for the application in SIS18. In this contribution, the status of the electron lens design will be reported putting special emphasis on its main components: the RF modulated electron gun, that is being developed within an ARIES collaboration, and the magnet system.
	Poster TUPAB200 [1.869 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB200
About •	paper received ※ 19 May 2021 paper accepted ※ 23 June 2021 issue date ※ 17 August 2021
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WEPAB384	Design and Beam Dynamics of the Electron Lens for Space Charge Compensation in SIS18	3614
	S. Artikova, D. Ondreka, K. Schulte-Urlichs, P.J. Spiller GSI, Darmstadt, Germany
	An electron lens for space charge compensation is being developed at GSI to increase the ion beam intensities in SIS18 for the FAIR project. It uses an electron beam of 10A maximum current at 30keV. The maximum magnetic field on-axis is 0.6T, considerably higher than the field of the existing electron cooler. The magnetic system of the lens consists of solenoids and toroids. The toroids’ vertical field component creates a significant horizontal orbit deflection in the circulating low rigidity ion beam. To correct this deflection, four correction dipoles have been introduced. As common for electron lenses, the high-power electron beam is not dumped at ground potential, but rather in a collector with a small bias potential with respect to the cathode. The present design foresees a collector at -27kV, leading to a power dissipation of 30kW, distributed over a large surface area by placing the collector in an appropriately shaped magnetic field of a pre-collector solenoid. This contribution reports on the design of the lens and presents the results of beam transport simulations for the electron beam (with space charge) and a representative ion beam, performed using the 3D CST STUDIO.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB384
About •	paper received ※ 20 May 2021 paper accepted ※ 05 July 2021 issue date ※ 31 August 2021
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THPAB157	Studying X-Ray Spectra of the SIS18 Electrostatic Septa to Measure Their Electric Field	4065
	B. Gålander, E. Kozlova, D. Ondreka, A. Sokolov, P.J. Spiller, J. Stadlmann GSI, Darmstadt, Germany
	The synchrotron SIS18 at GSI uses resonant extraction for slow beam extraction on the order of seconds. For some time, there has been an unexplained discrepancy of the slow extraction with a lower extraction efficiency than expected at the highest beam energies. Recent machine studies have indicated that the deflection by the electrostatic septum might be less than the nominal 2.5 mrad, leading to increased losses at the magnetic septum. In this paper, we pursue an idea to directly measure the voltage of the electrode gap by utilizing the fact that dark current electrons accelerated in the gap of the electrostatic extraction septum generate Bremsstrahlung X-rays when hitting the anode. The high-energy cut-off of the X-ray spectra then corresponds to the voltage of the electrode gap. Measurements of the X-ray spectra at the extraction septum of SIS18 have been performed using a solid-state CdTe detector. This technique provides an in-situ measurement of the voltage applied to the electrostatic extraction channel and has proven to be a useful diagnostics tool.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB157
About •	paper received ※ 19 May 2021 paper accepted ※ 02 September 2021 issue date ※ 19 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Advanced Concepts and Technologies for Heavy Ion Synchrotrons

594

P.J. Spiller, O. Boine-Frankenheim, L.H.J. Bozyk, S. Klammes, H. Kollmus, D. Ondreka, I. Pongrac, N. Pyka, C. Roux, K. Sugita, St. Wilfert, T. Winkler, D.F.A. Winters
GSI, Darmstadt, Germany

New concepts and technologies are developed to advance the performance of heavy ion synchrotrons. Besides fast ramping of superconducting magnets, extreme UHV technologies to stabilize dynamic vacuum and charge related loss, broad band MA cavities, space charge compensation by means of electron lenses and new cooling technologies, e.g. laser cooling, show great promise to advance the forefront of beam parameters. Several of these technologies and concepts are developed and tested at GSI/FAIR. Progress and plans will be reported.

Poster MOPAB175 [1.367 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB175

About •

paper received ※ 11 May 2021 paper accepted ※ 21 May 2021 issue date ※ 20 August 2021

Export •

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

TUPAB200

Status of the Electron Lens for Space Charge Compensation in SIS18

1880

K. Schulte-Urlichs, S. Artikova, D. Ondreka, P.J. Spiller
GSI, Darmstadt, Germany
P. Apse-Apsitis, I. Steiks
Riga Technical University, Riga, Latvia
M. Droba, O. Meusel, H. Podlech, K.I. Thoma
IAP, Frankfurt am Main, Germany

At GSI a project has been initiated to investigate the option of space charge compensation (SCC) by use of an electron lens in order to overcome space charge (SC) limits in the synchrotrons SIS18 and SIS100 for the Facility for Antiproton and Ion Research (FAIR). The repeated crossing of resonance lines due to the synchrotron motion in bunched beams is considered one of the main drivers of SC induced beam loss in the synchrotrons. Electron lenses provide a compensation of ion beam SC by virtue of their negative charge interacting with the ions in the overlap region while a time-varying compensation can be achieved by the modulation of the electron beam. In order to demonstrate space charge compensation of bunched ion beams, an electron lens is under development for the application in SIS18. In this contribution, the status of the electron lens design will be reported putting special emphasis on its main components: the RF modulated electron gun, that is being developed within an ARIES collaboration, and the magnet system.

Poster TUPAB200 [1.869 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB200

About •

paper received ※ 19 May 2021 paper accepted ※ 23 June 2021 issue date ※ 17 August 2021

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

WEPAB384

Design and Beam Dynamics of the Electron Lens for Space Charge Compensation in SIS18

3614

S. Artikova, D. Ondreka, K. Schulte-Urlichs, P.J. Spiller
GSI, Darmstadt, Germany

An electron lens for space charge compensation is being developed at GSI to increase the ion beam intensities in SIS18 for the FAIR project. It uses an electron beam of 10A maximum current at 30keV. The maximum magnetic field on-axis is 0.6T, considerably higher than the field of the existing electron cooler. The magnetic system of the lens consists of solenoids and toroids. The toroids’ vertical field component creates a significant horizontal orbit deflection in the circulating low rigidity ion beam. To correct this deflection, four correction dipoles have been introduced. As common for electron lenses, the high-power electron beam is not dumped at ground potential, but rather in a collector with a small bias potential with respect to the cathode. The present design foresees a collector at -27kV, leading to a power dissipation of 30kW, distributed over a large surface area by placing the collector in an appropriately shaped magnetic field of a pre-collector solenoid. This contribution reports on the design of the lens and presents the results of beam transport simulations for the electron beam (with space charge) and a representative ion beam, performed using the 3D CST STUDIO.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB384

About •

paper received ※ 20 May 2021 paper accepted ※ 05 July 2021 issue date ※ 31 August 2021

Export •

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

THPAB157

Studying X-Ray Spectra of the SIS18 Electrostatic Septa to Measure Their Electric Field

4065

B. Gålander, E. Kozlova, D. Ondreka, A. Sokolov, P.J. Spiller, J. Stadlmann
GSI, Darmstadt, Germany

The synchrotron SIS18 at GSI uses resonant extraction for slow beam extraction on the order of seconds. For some time, there has been an unexplained discrepancy of the slow extraction with a lower extraction efficiency than expected at the highest beam energies. Recent machine studies have indicated that the deflection by the electrostatic septum might be less than the nominal 2.5 mrad, leading to increased losses at the magnetic septum. In this paper, we pursue an idea to directly measure the voltage of the electrode gap by utilizing the fact that dark current electrons accelerated in the gap of the electrostatic extraction septum generate Bremsstrahlung X-rays when hitting the anode. The high-energy cut-off of the X-ray spectra then corresponds to the voltage of the electrode gap. Measurements of the X-ray spectra at the extraction septum of SIS18 have been performed using a solid-state CdTe detector. This technique provides an in-situ measurement of the voltage applied to the electrostatic extraction channel and has proven to be a useful diagnostics tool.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB157

About •

paper received ※ 19 May 2021 paper accepted ※ 02 September 2021 issue date ※ 19 August 2021

Export •

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