IPAC2019 - List of Authors (Albright, S.C.P.)

Paper	Title	Page
MOPTS086	Identification and Compensation of Betatronic Resonances in the Proton Synchrotron Booster at 160 Mev	1054
	A. Santamaría García, S.C.P. Albright, F. Antoniou, F. Asvesta, H. Bartosik, G.P. Di Giovanni, B. Mikulec CERN, Geneva, Switzerland F. Asvesta NTUA, Athens, Greece H. Rafique University of Manchester, Manchester, United Kingdom
	The Proton Synchrotron Booster (PSB) is the first circular accelerator in the injector chain to the Large Hadron Collider (LHC) and accelerates protons from 50 MeV to 1.4 GeV. The PSB will need to deliver two times the current brightness after the LHC Injectors Upgrade (LIU) in order to meet the High Luminosity LHC (HL-LHC) beam requirements. At the current injection energy a large incoherent space charge tune spread limits the brightness of the beams, which is one of the main motivations to increase the injection energy to 160 MeV with the injection provided by Linac4, a new H⁻ linear accelerator. The higher injection energy will allow doubling the beam intensity while maintaining a space charge tune spread similar to current values. The degradation of the beam brightness due to the tune spread can be minimized with a proper choice of working point and an efficient compensation of resonances. In this paper, we present the measurement of the betatronic resonances in the four rings of the PSB at 160 MeV before the Long Shutdown 2, as well as the results of a proposed compensation scheme.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS086
About •	paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS087	Transverse Emittance Studies at Extraction of the CERN PS Booster	1058
	F. Antoniou, S.C.P. Albright, F. Asvesta, H. Bartosik, G.P. Di Giovanni, V. Forte, M.A. Fraser, A. Garcia-Tabares, A. Huschauer, B. Mikulec, T. Prebibaj, A. Santamaría García, P.K. Skowroński CERN, Meyrin, Switzerland F. Asvesta NTUA, Athens, Greece T. Prebibaj National Technical University of Athens, Zografou, Greece
	Transverse emittance discrepancy in the beam transfer between the Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS) is observed in operational conditions for the LHC beams at CERN. The ongoing LHC Injectors Upgrade (LIU) project requires a tight budget for beam degradation along the injector chain and therefore the reason for this emittance discrepancy needs to be understood. Systematic measurements have been performed for various beam characteristics (beam intensity, transverse and longitudinal emittance). In this paper, a comparison between the emittance measurements using all available beam instrumentation with different emittance computation algorithms is presented. The results are compared to measurements at PS injection. Furthermore, the impact on the LIU project requirements for the emittance preservation along the LHC Injectors Complex is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS087
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP021	Frequency Modulated Capture of Cooled Coasting Ion Beams	2356
	S.C.P. Albright, M.E. Angoletta CERN, Geneva, Switzerland
	Transverse space charge effects in the Low Energy Ion Ring (LEIR) at CERN have been shown to be a major source of particle losses, which can be mitigated with a larger RMS longitudinal emittance. However, due to electron cooling during the injection plateau, the longitudinal density is very high prior to RF capture. In addition there is an uncontrolled cycle to cycle variation in the revolution frequency of the coasting beam on the flat bottom, which degrades the beam quality at capture. In this paper we show that applying an RF frequency modulation during the capture process allows both a controlled blow-up of the longitudinal emittance and a very good reproducibility in the longitudinal distribution, which in turn improves beam transmission through the machine.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP021
About •	paper received ※ 29 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMP026	Emittance Dilution from the CERN Proton Synchrotron Booster’s Extraction Kickers	2371
	M.A. Fraser, S.C.P. Albright, F. Antoniou, G.P. Di Giovanni, Y. Dutheil, V. Forte, A. Huschauer, F. Roncarolo CERN, Meyrin, Switzerland
	Understanding the different sources of emittance dilution along the LHC injector chain is an important part of providing the high brightness proton beams demanded by the LHC Injectors Upgrade (LIU) project. In this context, the first beam-based measurements of the magnetic waveforms of the Proton Synchrotron Booster’s (PSB) extraction kickers were carried out and used to quantify the transverse emittance blow-up during extraction and transfer to the Proton Synchrotron (PS). In this contribution, the waveform measurement technique will be briefly outlined before the results and their implications for the LIU project and beam performance reach are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP026
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB066	Beam Based Measurements of Relative RF Phase	3950
	S.C.P. Albright CERN, Geneva, Switzerland M.D. Kuczynski LPCT, Vandoeuvre-lès-Nancy Cedex, France
	The ferrite loaded RF cavities of the CERN Proton Synchrotron Booster will be replaced with FinemetTM loaded cavities during Long Shutdown 2 2019-2020). To fully realise the potential of the new cavities, the relative RF phases must be aligned along the acceleration ramp, where the revolution frequency changes by nearly a factor of 2. A beam based method of measuring the relative phase between the cavities is desired to give the best possible compensation for the frequency dependent phase shift. In this paper we present an operationally viable method to measure the phase shift as a function of RF frequency. The relative phase of the RF cavities can be aligned to within a few degrees, giving an error on the voltage seen by the beam of less than 1%.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB066
About •	paper received ※ 08 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB067	Time Varying RF Phase Noise for Longitudinal Emittance Blow-Up	3954
	S.C.P. Albright CERN, Geneva, Switzerland D. Quartullo Sapienza University of Rome, Rome, Italy
	RF phase noise was shown to be effective for controlled longitudinal emittance blow-up in the Proton Synchrotron Booster (PSB) at CERN during beam tests in 2017, with further developments in 2018. At CERN, RF phase noise is used operationally in the Super Proton Synchrotron (SPS) and Large Hadron Collider (LHC). In this paper we show that it is suitable for operation with a variety of beam types in the PSB. In the PSB the synchrotron frequency changes by approximately a factor 4 during the 500 ms acceleration ramp, requiring large changes in the frequency band of the noise. During 2018, a new method of calculating the noise parameters has been demonstrated, which gives upper and lower bounds to the noise frequency band that are smoothly varying through the ramp. The new calculation method has been applied to operational beams accelerated in both single and double RF harmonics, the final results are presented here.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB067
About •	paper received ※ 29 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB068	Upgrade of CERN’s PSB Digital Low-Level RF System	3958
	M.E. Angoletta, S.C.P. Albright, A. Findlay, M. Jaussi, J.C. Molendijk, N. Pittet CERN, Meyrin, Switzerland
	The CERN PS Booster (PSB) is the first circular accelerator in the LHC proton injector chain. The upgrade of this four-ring machine is underway within the framework of the LHC Injectors Upgrade project. The existing digital Low-Level RF (LLRF) system will also be upgraded. This paper outlines the LLRF capabilities required, their implementation and the challenges involved. Results of tests carried out to prepare for the LLRF upgrade are given.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB068
About •	paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB070	A New Digital Low-Level RF and Longitudinal Diagnostic System for CERN’s AD	3966
	M.E. Angoletta, S.C.P. Albright, A. Findlay, M. Jaussi, J.C. Molendijk, V.R. Myklebust CERN, Meyrin, Switzerland
	The Antiproton Decelerator (AD) has been routinely providing 3 E7 antiprotons since July 2000 at 100 MeV/c from 3.5 GeV/c. It will be refurbished during the Long Shutdown 2 (LS2) to provide reliable operation for the new Extra Low ENergy Antiproton (ELENA) ring. AD will be equipped with a new digital Low-Level RF (LLRF) system before its restart in 2021. Diagnostics to measure beam intensity, Δp/p and Schottky spectra will also be developed. This paper is an overview of the planned capabilities and implementations, as well as of the challenges to overcome.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB070
About •	paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Identification and Compensation of Betatronic Resonances in the Proton Synchrotron Booster at 160 Mev

1054

A. Santamaría García, S.C.P. Albright, F. Antoniou, F. Asvesta, H. Bartosik, G.P. Di Giovanni, B. Mikulec
CERN, Geneva, Switzerland
F. Asvesta
NTUA, Athens, Greece
H. Rafique
University of Manchester, Manchester, United Kingdom

The Proton Synchrotron Booster (PSB) is the first circular accelerator in the injector chain to the Large Hadron Collider (LHC) and accelerates protons from 50 MeV to 1.4 GeV. The PSB will need to deliver two times the current brightness after the LHC Injectors Upgrade (LIU) in order to meet the High Luminosity LHC (HL-LHC) beam requirements. At the current injection energy a large incoherent space charge tune spread limits the brightness of the beams, which is one of the main motivations to increase the injection energy to 160 MeV with the injection provided by Linac4, a new H⁻ linear accelerator. The higher injection energy will allow doubling the beam intensity while maintaining a space charge tune spread similar to current values. The degradation of the beam brightness due to the tune spread can be minimized with a proper choice of working point and an efficient compensation of resonances. In this paper, we present the measurement of the betatronic resonances in the four rings of the PSB at 160 MeV before the Long Shutdown 2, as well as the results of a proposed compensation scheme.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS086

About •

paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

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

MOPTS087

Transverse Emittance Studies at Extraction of the CERN PS Booster

1058

F. Antoniou, S.C.P. Albright, F. Asvesta, H. Bartosik, G.P. Di Giovanni, V. Forte, M.A. Fraser, A. Garcia-Tabares, A. Huschauer, B. Mikulec, T. Prebibaj, A. Santamaría García, P.K. Skowroński
CERN, Meyrin, Switzerland
F. Asvesta
NTUA, Athens, Greece
T. Prebibaj
National Technical University of Athens, Zografou, Greece

Transverse emittance discrepancy in the beam transfer between the Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS) is observed in operational conditions for the LHC beams at CERN. The ongoing LHC Injectors Upgrade (LIU) project requires a tight budget for beam degradation along the injector chain and therefore the reason for this emittance discrepancy needs to be understood. Systematic measurements have been performed for various beam characteristics (beam intensity, transverse and longitudinal emittance). In this paper, a comparison between the emittance measurements using all available beam instrumentation with different emittance computation algorithms is presented. The results are compared to measurements at PS injection. Furthermore, the impact on the LIU project requirements for the emittance preservation along the LHC Injectors Complex is discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS087

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

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

WEPMP021

Frequency Modulated Capture of Cooled Coasting Ion Beams

2356

S.C.P. Albright, M.E. Angoletta
CERN, Geneva, Switzerland

Transverse space charge effects in the Low Energy Ion Ring (LEIR) at CERN have been shown to be a major source of particle losses, which can be mitigated with a larger RMS longitudinal emittance. However, due to electron cooling during the injection plateau, the longitudinal density is very high prior to RF capture. In addition there is an uncontrolled cycle to cycle variation in the revolution frequency of the coasting beam on the flat bottom, which degrades the beam quality at capture. In this paper we show that applying an RF frequency modulation during the capture process allows both a controlled blow-up of the longitudinal emittance and a very good reproducibility in the longitudinal distribution, which in turn improves beam transmission through the machine.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP021

About •

paper received ※ 29 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

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

WEPMP026

Emittance Dilution from the CERN Proton Synchrotron Booster’s Extraction Kickers

2371

M.A. Fraser, S.C.P. Albright, F. Antoniou, G.P. Di Giovanni, Y. Dutheil, V. Forte, A. Huschauer, F. Roncarolo
CERN, Meyrin, Switzerland

Understanding the different sources of emittance dilution along the LHC injector chain is an important part of providing the high brightness proton beams demanded by the LHC Injectors Upgrade (LIU) project. In this context, the first beam-based measurements of the magnetic waveforms of the Proton Synchrotron Booster’s (PSB) extraction kickers were carried out and used to quantify the transverse emittance blow-up during extraction and transfer to the Proton Synchrotron (PS). In this contribution, the waveform measurement technique will be briefly outlined before the results and their implications for the LIU project and beam performance reach are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP026

About •

paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

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

THPRB066

Beam Based Measurements of Relative RF Phase

3950

S.C.P. Albright
CERN, Geneva, Switzerland
M.D. Kuczynski
LPCT, Vandoeuvre-lès-Nancy Cedex, France

The ferrite loaded RF cavities of the CERN Proton Synchrotron Booster will be replaced with FinemetTM loaded cavities during Long Shutdown 2 2019-2020). To fully realise the potential of the new cavities, the relative RF phases must be aligned along the acceleration ramp, where the revolution frequency changes by nearly a factor of 2. A beam based method of measuring the relative phase between the cavities is desired to give the best possible compensation for the frequency dependent phase shift. In this paper we present an operationally viable method to measure the phase shift as a function of RF frequency. The relative phase of the RF cavities can be aligned to within a few degrees, giving an error on the voltage seen by the beam of less than 1%.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB066

About •

paper received ※ 08 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

THPRB067

Time Varying RF Phase Noise for Longitudinal Emittance Blow-Up

3954

S.C.P. Albright
CERN, Geneva, Switzerland
D. Quartullo
Sapienza University of Rome, Rome, Italy

RF phase noise was shown to be effective for controlled longitudinal emittance blow-up in the Proton Synchrotron Booster (PSB) at CERN during beam tests in 2017, with further developments in 2018. At CERN, RF phase noise is used operationally in the Super Proton Synchrotron (SPS) and Large Hadron Collider (LHC). In this paper we show that it is suitable for operation with a variety of beam types in the PSB. In the PSB the synchrotron frequency changes by approximately a factor 4 during the 500 ms acceleration ramp, requiring large changes in the frequency band of the noise. During 2018, a new method of calculating the noise parameters has been demonstrated, which gives upper and lower bounds to the noise frequency band that are smoothly varying through the ramp. The new calculation method has been applied to operational beams accelerated in both single and double RF harmonics, the final results are presented here.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB067

About •

paper received ※ 29 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

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

THPRB068

Upgrade of CERN’s PSB Digital Low-Level RF System

3958

M.E. Angoletta, S.C.P. Albright, A. Findlay, M. Jaussi, J.C. Molendijk, N. Pittet
CERN, Meyrin, Switzerland

The CERN PS Booster (PSB) is the first circular accelerator in the LHC proton injector chain. The upgrade of this four-ring machine is underway within the framework of the LHC Injectors Upgrade project. The existing digital Low-Level RF (LLRF) system will also be upgraded. This paper outlines the LLRF capabilities required, their implementation and the challenges involved. Results of tests carried out to prepare for the LLRF upgrade are given.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB068

About •

paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

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

THPRB070

A New Digital Low-Level RF and Longitudinal Diagnostic System for CERN’s AD

3966

M.E. Angoletta, S.C.P. Albright, A. Findlay, M. Jaussi, J.C. Molendijk, V.R. Myklebust
CERN, Meyrin, Switzerland

The Antiproton Decelerator (AD) has been routinely providing 3 E7 antiprotons since July 2000 at 100 MeV/c from 3.5 GeV/c. It will be refurbished during the Long Shutdown 2 (LS2) to provide reliable operation for the new Extra Low ENergy Antiproton (ELENA) ring. AD will be equipped with a new digital Low-Level RF (LLRF) system before its restart in 2021. Diagnostics to measure beam intensity, Δp/p and Schottky spectra will also be developed. This paper is an overview of the planned capabilities and implementations, as well as of the challenges to overcome.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB070

About •

paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

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