IPAC2021 - List of Authors (Huschauer, A.)

Paper	Title	Page
WEXB07	Transverse Beam Profile Measurements from Extraction Losses in the PS	2548
	J.R. Hunt, F. Cerutti, L.S. Esposito, M. Giovannozzi, A. Huschauer, G. Russo CERN, Geneva, Switzerland G. Russo Goethe Universität Frankfurt, Frankfurt am Main, Germany
	During Multi-Turn Extraction (MTE) of continuous beams in the Proton Synchrotron (PS) at CERN, losses are generated on the blade of both the active and non-active septum during the rise time of the extraction kickers. Utilising pCVD Diamond detectors, secondary signal generated from these losses is measured. The high time resolution of these devices allows for insight into the detail of the horizontal beam distribution during extraction, and hence useful information such as the horizontal beam emittance may be computed. In this contribution, FLUKA simulations to relate the detector response to the beam impact conditions on the blades of the two septa are presented. The dependence on the beam angle, magnetic fringe field, and positioning of the detector is explored. Finally, realistic beam distributions are used to determine expected signal profiles at each septum.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXB07
About •	paper received ※ 18 May 2021 paper accepted ※ 20 July 2021 issue date ※ 27 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB243	Longitudinal Microwave Instability Study at Transition Crossing with Ion Beams in the CERN PS	3197
	A. Lasheen, H. Damerau, A. Huschauer, B.K. Popovic CERN, Geneva, Switzerland
	The luminosity of lead ion collisions in the Large Hadron Collider (LHC) was significantly increased during the 2018 ion run by reducing the bunch spacing from 100 ns to 75 ns, allowing to increase the total number of bunches. With the new 75 ns variant, three instead of four bunches are generated each cycle in the Low Energy Ion Ring (LEIR) and the Proton Synchrotron (PS) with up to 30% larger intensity per bunch. The beam was produced with satisfactory quality but at the limit of stability in the injectors. In particular, the minimum longitudinal emittance in the PS is limited by a strong longitudinal microwave instability occurring just after transition crossing. The uncontrolled blow-up generates tails, which translate into an unacceptably large satellite population following the RF manipulations prior to extraction from the PS. In this paper, instability measurements are compared to particle simulations using the latest PS impedance model to identify the driving impedance sources. Moreover, means to mitigate the instability are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB243
About •	paper received ※ 19 May 2021 paper accepted ※ 06 July 2021 issue date ※ 29 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Transverse Beam Profile Measurements from Extraction Losses in the PS

2548

J.R. Hunt, F. Cerutti, L.S. Esposito, M. Giovannozzi, A. Huschauer, G. Russo
CERN, Geneva, Switzerland
G. Russo
Goethe Universität Frankfurt, Frankfurt am Main, Germany

During Multi-Turn Extraction (MTE) of continuous beams in the Proton Synchrotron (PS) at CERN, losses are generated on the blade of both the active and non-active septum during the rise time of the extraction kickers. Utilising pCVD Diamond detectors, secondary signal generated from these losses is measured. The high time resolution of these devices allows for insight into the detail of the horizontal beam distribution during extraction, and hence useful information such as the horizontal beam emittance may be computed. In this contribution, FLUKA simulations to relate the detector response to the beam impact conditions on the blades of the two septa are presented. The dependence on the beam angle, magnetic fringe field, and positioning of the detector is explored. Finally, realistic beam distributions are used to determine expected signal profiles at each septum.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXB07

About •

paper received ※ 18 May 2021 paper accepted ※ 20 July 2021 issue date ※ 27 August 2021

Export •

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

WEPAB243

Longitudinal Microwave Instability Study at Transition Crossing with Ion Beams in the CERN PS

3197

A. Lasheen, H. Damerau, A. Huschauer, B.K. Popovic
CERN, Geneva, Switzerland

The luminosity of lead ion collisions in the Large Hadron Collider (LHC) was significantly increased during the 2018 ion run by reducing the bunch spacing from 100 ns to 75 ns, allowing to increase the total number of bunches. With the new 75 ns variant, three instead of four bunches are generated each cycle in the Low Energy Ion Ring (LEIR) and the Proton Synchrotron (PS) with up to 30% larger intensity per bunch. The beam was produced with satisfactory quality but at the limit of stability in the injectors. In particular, the minimum longitudinal emittance in the PS is limited by a strong longitudinal microwave instability occurring just after transition crossing. The uncontrolled blow-up generates tails, which translate into an unacceptably large satellite population following the RF manipulations prior to extraction from the PS. In this paper, instability measurements are compared to particle simulations using the latest PS impedance model to identify the driving impedance sources. Moreover, means to mitigate the instability are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB243

About •

paper received ※ 19 May 2021 paper accepted ※ 06 July 2021 issue date ※ 29 August 2021

Export •

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