IPAC2014 - List of Authors (Rijoff, T.L.)

Paper	Title	Page
TUPRI028	Review of Rest Gas Interaction at Very Low Energies applied to the Extra Low ENergy Antiproton ring ELENA	1621
	C. Carli, T.L. Rijoff CERN, Geneva, Switzerland O. Karamyshev, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom O. Karamyshev, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	The Extremely Low ENergy Antiproton ring (ELENA) is a small synchrotron equipped with an electron cooler, which shall be constructed at CERN to decelerate antiprotons to energies as low as 100 keV. Scattering of beam particles on rest gas molecules may have a detrimental effect at such low energies and leads to stringent vacuum requirements. Within this contribution scattering of the stored beam on rest gas molecules is discussed for very low beam energies. It is important to carefully distinguish between antiprotons scattered out of the acceptance and lost, and those remaining inside the aperture to avoid overestimation of emittance blow-up. Furthermore, many antiprotons do not interact at all during the time they are stored in ELENA and hence this is not a multiple scattering process
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI028
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRI063	Electromagnetic Simulations for Non-ultrarelativistic Beams and Application to the CERN Low Energy Machines	1718
	C. Zannini, N. Biancacci, T.L. Rijoff, G. Rumolo CERN, Geneva, Switzerland T.L. Rijoff TU Darmstadt, Darmstadt, Germany
	In the framework of the PS-Booster upgrade project an accurate impedance model is needed in order to determine the effect on the beam stability and assess the impact of the new devices to be installed in the machine. CST 3-D EM simulations are widely used to estimate the impedance contribution of the different devices along the CERN accelerator complex. Unlike the highly relativistic case, in which the reliability of the EM solver has been proved in many specific cases by comparing simulations with analytical results, the nonrelativistic case has been so far not yet benchmarked. In order to use systematically CST 3-D EM simulations for the PS-Booster, or even lower energy machines like the antiproton decelerator ELENA, a validation campaign has been carried out. The main complication to single out the beam coupling impedance, as resulting from the interaction of the beam with the surroundings, consisted of removing reliably the strong contribution of the direct space charge of the source bunch, which is included in the EM calculation. The simulation results were then benchmarked with the analytical results for the case of a PEC cylindrical tube and of a ferrite loaded kicker.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI063
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Review of Rest Gas Interaction at Very Low Energies applied to the Extra Low ENergy Antiproton ring ELENA

1621

C. Carli, T.L. Rijoff
CERN, Geneva, Switzerland
O. Karamyshev, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
O. Karamyshev, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

The Extremely Low ENergy Antiproton ring (ELENA) is a small synchrotron equipped with an electron cooler, which shall be constructed at CERN to decelerate antiprotons to energies as low as 100 keV. Scattering of beam particles on rest gas molecules may have a detrimental effect at such low energies and leads to stringent vacuum requirements. Within this contribution scattering of the stored beam on rest gas molecules is discussed for very low beam energies. It is important to carefully distinguish between antiprotons scattered out of the acceptance and lost, and those remaining inside the aperture to avoid overestimation of emittance blow-up. Furthermore, many antiprotons do not interact at all during the time they are stored in ELENA and hence this is not a multiple scattering process

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI028

Export •

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

TUPRI063

Electromagnetic Simulations for Non-ultrarelativistic Beams and Application to the CERN Low Energy Machines

1718

C. Zannini, N. Biancacci, T.L. Rijoff, G. Rumolo
CERN, Geneva, Switzerland
T.L. Rijoff
TU Darmstadt, Darmstadt, Germany

In the framework of the PS-Booster upgrade project an accurate impedance model is needed in order to determine the effect on the beam stability and assess the impact of the new devices to be installed in the machine. CST 3-D EM simulations are widely used to estimate the impedance contribution of the different devices along the CERN accelerator complex. Unlike the highly relativistic case, in which the reliability of the EM solver has been proved in many specific cases by comparing simulations with analytical results, the nonrelativistic case has been so far not yet benchmarked. In order to use systematically CST 3-D EM simulations for the PS-Booster, or even lower energy machines like the antiproton decelerator ELENA, a validation campaign has been carried out. The main complication to single out the beam coupling impedance, as resulting from the interaction of the beam with the surroundings, consisted of removing reliably the strong contribution of the direct space charge of the source bunch, which is included in the EM calculation. The simulation results were then benchmarked with the analytical results for the case of a PEC cylindrical tube and of a ferrite loaded kicker.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI063

Export •

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