IPAC2018 - List of Authors (Roncarolo, F.)

Paper	Title	Page
MOPMF054	Comparison of Different Transverse Emittance Measurement Techniques in the Proton Synchrotron Booster	232
	G.P. Di Giovanni, S.C.P. Albright, V. Forte, M.A. Fraser, G. Guidoboni, B. Mikulec, F. Roncarolo, A. Santamaría García CERN, Geneva, Switzerland
	The measurement of the transverse emittance in an accelerator is a crucial parameter to evaluate the performance of the machine and to understand beam dynamics processes. In recent years, controlling and understanding the emittance became particularly relevant in the Proton Synchrotron Booster (PSB) at CERN as part of the LHC Injectors Upgrade (LIU). The LIU project is a necessary step to achieve the goals of the High-Luminosity LHC project. In this framework, an accurate and reliable emittance measurement of high brightness beams is mandatory to study the brightness reach of the LHC injectors. In the PSB there are two main instruments available for emittance measurements: wire scanners and secondary-emission (SEM) grids. In this paper emittance measurements performed during the 2017 physics run with these two systems are compared, taking into account various systematic error sources.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF054
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TUPAF020	Performance of the CERN Low Energy Ion Ring (LEIR) with Xenon beams	705
	R. Alemany-Fernández, S.C.P. Albright, O. Andujar, M.E. Angoletta, J. Axensalva, H. Bartosik, G. Baud, N. Biancacci, M. Bozzolan, S. Cettour Cave, K. Cornelis, J. Dalla-Costa, M. Delrieux, A. Dworak, A. Findlay, F. Follin, A. Frassier, M. Gabriel, A. Guerrero, M. Haase, S. Hirlaender, S. Jensen, V. Kain, L.V. Kolbeck, Y. Le Borgne, D. Manglunki, O. Marqversen, S. Massot, D. Moreno Garcia, D.J.P. Nicosia, S. Pasinelli, L. Pereira, D. Perez, A. Rey, J.P. Ridewood, F. Roncarolo, Á. Saá Hernández, R. Scrivens, O.G. Sveen, G. Tranquille, E. Veyrunes CERN, Geneva, Switzerland
	In 2017 the CERN Low Energy Ion Ring demonstrated once more the feasibility of injecting, accumulating, cooling and accelerating a new nuclei, 129Xe39 . The operation of this new ion species started at the beginning of March with the start up of the xenon ion source and the Linac3. Ten weeks later the beam arrived to the Low Energy Ion Ring (LEIR) triggering the start of several weeks of beam commissioning in view of providing the injector complex with Xenon beams for different experiments and a series of machine development experiments in LEIR. Two types of beams were setup, the so called EARLY beam, with a single injection into LEIR from Linac3, and the NOMINAL beam with up to seven injections. 2017 was as well an interesting year for LEIR because several improvements in the control system of the accelerator and in the beam instrumentation were done in view of increasing the machine reliability. This paper summarises the beam commissioning phase and all the improvements carried out during 2017.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF020
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TUPAF047	Systematic Studies of Transverse Emittance Measurements Along the CERN PS Booster Cycle	806
	A. Santamaría García, S.C.P. Albright, H. Bartosik, J.A. Briz Monago, G.P. Di Giovanni, V. Forte, B. Mikulec, F. Roncarolo, V. Vlachoudis CERN, Geneva, Switzerland
	The CERN Proton Synchrotron Booster (PSB) will need to deliver 2 times the current brightness to the Large Hadron Collider (LHC) after the LHC Injectors Upgrade (LIU) to meet the High-Luminosity-LHC beam requirements. Beam intensity and transverse emittance are the key parameters to increase brightness, the latter being more difficult to manipulate. It is, therefore, crucial to monitor not only the emittance evolution between the different injectors but also along each acceleration cycle. To this end, detailed emittance measurements were carried out for the four rings of the PSB at various times in the cycle with different beam types. A thorough analysis of systematic error sources was conducted including multiple Coulomb scattering happening during profile measurements with wire scanners, where experimental and analytical treatments of the emittance blow-up were compared to FLUKA simulations. In order to properly account for the dispersive contribution, the full momentum spread profile was considered using a deconvolution method. We conclude with an assessment of this first comprehensive emittance evolution measurement along the PSB cycle.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF047
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TUPAF054	Slow Extraction Efficiency Measurements at the CERN SPS	834
	M.A. Fraser, K. Cornelis, L.S. Esposito, B. Goddard, V. Kain, F. Roncarolo, L.S. Stoel, F.M. Velotti CERN, Geneva, Switzerland
	The high efficiency of most slow extraction systems makes quantifying the exact amount of beam lost in the process extremely challenging. This is compounded by the lack of time structure in the extracted beam, as is typically required by the high-energy physics experiments, and the difficulty in accurately calibrating D.C. intensity monitors in the extraction line at count rates of ~ 10¹³ Hz. As a result, it is common for the extraction inefficiency to be measured by calibrating the beam loss signal induced by the slow extraction process itself. In this paper, measurements of the extraction efficiency performed at the CERN Super Proton Synchrotron for the third-integer resonant slow extraction of 400 GeV protons over recent years will be presented and compared to expectation from simulation. The technique employed will be discussed along with its limitations and an outlook towards a future online extraction efficiency monitoring system will be given.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF054
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WEPAL074	Commissioning of the Operational Laser Emittance Monitors for LINAC4 at CERN	2357
	T. Hofmann, G.E. Boorman, A. Bosco, S.M. Gibson Royal Holloway, University of London, Surrey, United Kingdom F. Roncarolo CERN, Geneva, Switzerland
	A laser-based emittance monitor has been developed to non-invasively measure the transverse emittance of the LINAC4 H⁻ beam at its top energy of 160MeV. After testing several sub-systems of the instrument during linac commissioning at intermediate energies, two instruments are now permanently installed. These instruments use a pulsed laser beam delivered to the accelerator tunnel by optical fibres before final focusing onto the H⁻ beam. The photons in the laser pulse detach electrons from the H⁻ ions, which can then be deflected into an electron multiplier. In addition, the resulting neutral H⁰ atoms can be separated from the main beam by a dipole magnet before being recorded by downstream diamond strip-detectors. By scanning the laser in the horizontal and vertical plane the beam profiles are obtained from the electron signals and the emittance can be reconstructed by the H⁰ profiles at the diamond detectors. This paper describes the final system layout that consists of two independent instruments, each measuring profile and emittance of the H⁻ beam in the horizontal and vertical plane and discusses the preliminary commissioning results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL074
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Paper

Title

Page

Comparison of Different Transverse Emittance Measurement Techniques in the Proton Synchrotron Booster

232

G.P. Di Giovanni, S.C.P. Albright, V. Forte, M.A. Fraser, G. Guidoboni, B. Mikulec, F. Roncarolo, A. Santamaría García
CERN, Geneva, Switzerland

The measurement of the transverse emittance in an accelerator is a crucial parameter to evaluate the performance of the machine and to understand beam dynamics processes. In recent years, controlling and understanding the emittance became particularly relevant in the Proton Synchrotron Booster (PSB) at CERN as part of the LHC Injectors Upgrade (LIU). The LIU project is a necessary step to achieve the goals of the High-Luminosity LHC project. In this framework, an accurate and reliable emittance measurement of high brightness beams is mandatory to study the brightness reach of the LHC injectors. In the PSB there are two main instruments available for emittance measurements: wire scanners and secondary-emission (SEM) grids. In this paper emittance measurements performed during the 2017 physics run with these two systems are compared, taking into account various systematic error sources.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF054

Export •

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

TUPAF020

Performance of the CERN Low Energy Ion Ring (LEIR) with Xenon beams

705

R. Alemany-Fernández, S.C.P. Albright, O. Andujar, M.E. Angoletta, J. Axensalva, H. Bartosik, G. Baud, N. Biancacci, M. Bozzolan, S. Cettour Cave, K. Cornelis, J. Dalla-Costa, M. Delrieux, A. Dworak, A. Findlay, F. Follin, A. Frassier, M. Gabriel, A. Guerrero, M. Haase, S. Hirlaender, S. Jensen, V. Kain, L.V. Kolbeck, Y. Le Borgne, D. Manglunki, O. Marqversen, S. Massot, D. Moreno Garcia, D.J.P. Nicosia, S. Pasinelli, L. Pereira, D. Perez, A. Rey, J.P. Ridewood, F. Roncarolo, Á. Saá Hernández, R. Scrivens, O.G. Sveen, G. Tranquille, E. Veyrunes
CERN, Geneva, Switzerland

In 2017 the CERN Low Energy Ion Ring demonstrated once more the feasibility of injecting, accumulating, cooling and accelerating a new nuclei, 129Xe39 . The operation of this new ion species started at the beginning of March with the start up of the xenon ion source and the Linac3. Ten weeks later the beam arrived to the Low Energy Ion Ring (LEIR) triggering the start of several weeks of beam commissioning in view of providing the injector complex with Xenon beams for different experiments and a series of machine development experiments in LEIR. Two types of beams were setup, the so called EARLY beam, with a single injection into LEIR from Linac3, and the NOMINAL beam with up to seven injections. 2017 was as well an interesting year for LEIR because several improvements in the control system of the accelerator and in the beam instrumentation were done in view of increasing the machine reliability. This paper summarises the beam commissioning phase and all the improvements carried out during 2017.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF020

Export •

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

TUPAF047

Systematic Studies of Transverse Emittance Measurements Along the CERN PS Booster Cycle

806

A. Santamaría García, S.C.P. Albright, H. Bartosik, J.A. Briz Monago, G.P. Di Giovanni, V. Forte, B. Mikulec, F. Roncarolo, V. Vlachoudis
CERN, Geneva, Switzerland

The CERN Proton Synchrotron Booster (PSB) will need to deliver 2 times the current brightness to the Large Hadron Collider (LHC) after the LHC Injectors Upgrade (LIU) to meet the High-Luminosity-LHC beam requirements. Beam intensity and transverse emittance are the key parameters to increase brightness, the latter being more difficult to manipulate. It is, therefore, crucial to monitor not only the emittance evolution between the different injectors but also along each acceleration cycle. To this end, detailed emittance measurements were carried out for the four rings of the PSB at various times in the cycle with different beam types. A thorough analysis of systematic error sources was conducted including multiple Coulomb scattering happening during profile measurements with wire scanners, where experimental and analytical treatments of the emittance blow-up were compared to FLUKA simulations. In order to properly account for the dispersive contribution, the full momentum spread profile was considered using a deconvolution method. We conclude with an assessment of this first comprehensive emittance evolution measurement along the PSB cycle.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF047

Export •

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

TUPAF054

Slow Extraction Efficiency Measurements at the CERN SPS

834

M.A. Fraser, K. Cornelis, L.S. Esposito, B. Goddard, V. Kain, F. Roncarolo, L.S. Stoel, F.M. Velotti
CERN, Geneva, Switzerland

The high efficiency of most slow extraction systems makes quantifying the exact amount of beam lost in the process extremely challenging. This is compounded by the lack of time structure in the extracted beam, as is typically required by the high-energy physics experiments, and the difficulty in accurately calibrating D.C. intensity monitors in the extraction line at count rates of ~ 10¹³ Hz. As a result, it is common for the extraction inefficiency to be measured by calibrating the beam loss signal induced by the slow extraction process itself. In this paper, measurements of the extraction efficiency performed at the CERN Super Proton Synchrotron for the third-integer resonant slow extraction of 400 GeV protons over recent years will be presented and compared to expectation from simulation. The technique employed will be discussed along with its limitations and an outlook towards a future online extraction efficiency monitoring system will be given.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF054

Export •

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

WEPAL074

Commissioning of the Operational Laser Emittance Monitors for LINAC4 at CERN

2357

T. Hofmann, G.E. Boorman, A. Bosco, S.M. Gibson
Royal Holloway, University of London, Surrey, United Kingdom
F. Roncarolo
CERN, Geneva, Switzerland

A laser-based emittance monitor has been developed to non-invasively measure the transverse emittance of the LINAC4 H⁻ beam at its top energy of 160MeV. After testing several sub-systems of the instrument during linac commissioning at intermediate energies, two instruments are now permanently installed. These instruments use a pulsed laser beam delivered to the accelerator tunnel by optical fibres before final focusing onto the H⁻ beam. The photons in the laser pulse detach electrons from the H⁻ ions, which can then be deflected into an electron multiplier. In addition, the resulting neutral H⁰ atoms can be separated from the main beam by a dipole magnet before being recorded by downstream diamond strip-detectors. By scanning the laser in the horizontal and vertical plane the beam profiles are obtained from the electron signals and the emittance can be reconstructed by the H⁰ profiles at the diamond detectors. This paper describes the final system layout that consists of two independent instruments, each measuring profile and emittance of the H⁻ beam in the horizontal and vertical plane and discusses the preliminary commissioning results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL074

Export •

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