COOL2021 - List of Authors (Tranquille, G.)

Paper	Title	Page
S503	AD/ELENA Electron Cooling Experience During and after CERNs Long Shutdown (LS2)	36
	D. Gamba, L. Bojtár, C. Carli, B. Dupuy, A. Frassier, L.V. Jørgensen, L. Ponce, G. Tranquille CERN, Geneva, Switzerland
	Electron cooling is a key ingredient of the Antimatter Factory at CERN, now composed of the AD and ELENA rings, both featuring an electron cooler. After the successful commissioning of the ELENA ring and electron cooling with antiprotons in 2018, the facility was shut down for the CERN long shutdown (LS2). In the meantime, ELENA has been operating with H⁻ ions generated from a local source, and electron cooling of H⁻ was demonstrated. The facility has restarted with antiproton operation during summer 2021, and it is now delivering 100 keV production beams through newly installed electro-static extraction lines to all the experiments for the very first time. We will give an overview of the experience gained and difficulties encountered during the restart of the AD and ELENA electron coolers. The experience with electron cooling of H⁻ beam in ELENA and the comparison with antiproton cooling will also be presented.
	Slides S503 [32.064 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2021-S503
About •	paper received ※ 03 November 2021 paper accepted ※ 01 December 2021 issue date ※ 07 December 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

P1010	Optimization of the Electron Emission From Carbon Nanotubes for Electron Cooling in ELENA	85
	B. Galante, G. Tranquille CERN, Meyrin, Switzerland J. Resta-López ICMUV, Paterna, Spain C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Electron cooling is a process that guarantees beam quality in low energy antimatter facilities. In ELENA the electron cooler allows to reduce the emittance blow-up of the antiproton beam, thus delivering highly focused and bright beams at the unprecedented low energy of 100 keV to the experiments. In order to have a "cold" beam at such low energy, the electron gun of the cooler must emit a monoenergetic and relatively intense electron beam. Simulations have shown that efficient cooling can be achieved with a 5 mA electron beam having transverse energy spread of less than 100 meV and longitudinal energy spread of about 1 meV. A thermionic gun is currently used in operation, although it limits the performances due to a relatively high transverse energy of the emitted beam (>> 100 meV). Therefore, an optimization of the ELENA e-cooler gun is currently being studied, with the aim to develop and design a cold cathode e-gun based on carbon nanotubes acting as cold electron field emitters. The use of carbon nanotube arrays for electron emission implies the need of an extracting grid in order to allow a stable and uniform emission at relatively low electric fields. The grid and its features become then critical to control the electron beam properties. In this contribution we present a simulation study of the current extraction from a field emitting material involving different extracting grid types and how they affect the beam properties. Eventually, we propose a new gun layout.
	Poster P1010 [0.850 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2021-P1010
About •	paper received ※ 23 October 2021 paper accepted ※ 22 November 2021 issue date ※ 10 December 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

P2004	A New Electron Cooler for the CERN Antiproton Decelerator (AD)	95
	G. Tranquille, J. Cenede, A. Frassier, L.V. Jørgensen, A. Sinturel, J.A.F. Somoza CERN, Meyrin, Switzerland
	The current electron cooler at the Antiproton Decelerator (AD) at CERN was built in the second half of the 1970s and is thus well over 40 years old. It was built for the Initial Cooling Experiment (ICE) where stochastic and electron cooling were tested to ascertain the feasibility of using these techniques to generate high intensity antiproton beams for the SPpS. The ICE electron cooler was subsequently upgraded and installed in LEAR (Low Energy Antiproton Ring) to help generate intense beams of antiprotons at low energies. After the stop of the antiproton physics at LEAR in 1996 and two years of studies of electron cooling of Pb ions, the electron cooler was moved to the AD where it has been in use ever since. With the new ELENA ring becoming operational, a major consolidation project has been launched to extend the life of the AD and as a part of this a new electron cooler for the AD is being built. In this paper, we describe some of the design considerations and challenges of this project as well as the expected gains in terms of cooling performance.
	Poster P2004 [3.193 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2021-P2004
About •	paper received ※ 25 October 2021 paper accepted ※ 13 December 2021 issue date ※ 15 November 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

AD/ELENA Electron Cooling Experience During and after CERNs Long Shutdown (LS2)

36

D. Gamba, L. Bojtár, C. Carli, B. Dupuy, A. Frassier, L.V. Jørgensen, L. Ponce, G. Tranquille
CERN, Geneva, Switzerland

Electron cooling is a key ingredient of the Antimatter Factory at CERN, now composed of the AD and ELENA rings, both featuring an electron cooler. After the successful commissioning of the ELENA ring and electron cooling with antiprotons in 2018, the facility was shut down for the CERN long shutdown (LS2). In the meantime, ELENA has been operating with H⁻ ions generated from a local source, and electron cooling of H⁻ was demonstrated. The facility has restarted with antiproton operation during summer 2021, and it is now delivering 100 keV production beams through newly installed electro-static extraction lines to all the experiments for the very first time. We will give an overview of the experience gained and difficulties encountered during the restart of the AD and ELENA electron coolers. The experience with electron cooling of H⁻ beam in ELENA and the comparison with antiproton cooling will also be presented.

Slides S503 [32.064 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2021-S503

About •

paper received ※ 03 November 2021 paper accepted ※ 01 December 2021 issue date ※ 07 December 2021

Export •

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

P1010

Optimization of the Electron Emission From Carbon Nanotubes for Electron Cooling in ELENA

85

B. Galante, G. Tranquille
CERN, Meyrin, Switzerland
J. Resta-López
ICMUV, Paterna, Spain
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Electron cooling is a process that guarantees beam quality in low energy antimatter facilities. In ELENA the electron cooler allows to reduce the emittance blow-up of the antiproton beam, thus delivering highly focused and bright beams at the unprecedented low energy of 100 keV to the experiments. In order to have a "cold" beam at such low energy, the electron gun of the cooler must emit a monoenergetic and relatively intense electron beam. Simulations have shown that efficient cooling can be achieved with a 5 mA electron beam having transverse energy spread of less than 100 meV and longitudinal energy spread of about 1 meV. A thermionic gun is currently used in operation, although it limits the performances due to a relatively high transverse energy of the emitted beam (>> 100 meV). Therefore, an optimization of the ELENA e-cooler gun is currently being studied, with the aim to develop and design a cold cathode e-gun based on carbon nanotubes acting as cold electron field emitters. The use of carbon nanotube arrays for electron emission implies the need of an extracting grid in order to allow a stable and uniform emission at relatively low electric fields. The grid and its features become then critical to control the electron beam properties. In this contribution we present a simulation study of the current extraction from a field emitting material involving different extracting grid types and how they affect the beam properties. Eventually, we propose a new gun layout.

Poster P1010 [0.850 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2021-P1010

About •

paper received ※ 23 October 2021 paper accepted ※ 22 November 2021 issue date ※ 10 December 2021

Export •

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

P2004

A New Electron Cooler for the CERN Antiproton Decelerator (AD)

95

G. Tranquille, J. Cenede, A. Frassier, L.V. Jørgensen, A. Sinturel, J.A.F. Somoza
CERN, Meyrin, Switzerland

The current electron cooler at the Antiproton Decelerator (AD) at CERN was built in the second half of the 1970s and is thus well over 40 years old. It was built for the Initial Cooling Experiment (ICE) where stochastic and electron cooling were tested to ascertain the feasibility of using these techniques to generate high intensity antiproton beams for the SPpS. The ICE electron cooler was subsequently upgraded and installed in LEAR (Low Energy Antiproton Ring) to help generate intense beams of antiprotons at low energies. After the stop of the antiproton physics at LEAR in 1996 and two years of studies of electron cooling of Pb ions, the electron cooler was moved to the AD where it has been in use ever since. With the new ELENA ring becoming operational, a major consolidation project has been launched to extend the life of the AD and as a part of this a new electron cooler for the AD is being built. In this paper, we describe some of the design considerations and challenges of this project as well as the expected gains in terms of cooling performance.

Poster P2004 [3.193 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2021-P2004

About •

paper received ※ 25 October 2021 paper accepted ※ 13 December 2021 issue date ※ 15 November 2021

Export •

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