LINAC2022 - List of Authors (Craievich, P.)

Paper	Title	Page
TU1PA01	A Discussion of Key Concepts for the Next Generation of High Brightness Injectors	324
	T.G. Lucas, P. Craievich, S. Reiche PSI, Villigen PSI, Switzerland
	The production of high brightness electron beams has been key to the success of the X-ray free-electron laser (XFEL) as the new frontier in X-ray sources. The past two decades have seen the commissioning of numerous XFEL facilities, which quickly surpassed Synchrotron light sources to become the most brilliant X-ray sources. Such facilities have, so far, heavily relied on room temperature S-band RF photoguns to produce the high brightness electron bunches required for lasing, however such photoguns are reaching their peak performance limit and new methods must be investigated to continue to increase the brightness of these facilities. This talk will begin with a review of the design and performance of several electron guns currently operational in XFELs. Following will be a discussion of current efforts in continuing to increase this peak brightness including moving to cold cathode schemes and the use of very high gradients on the cathode. Finally we will describe ongoing activities at PSI to develop the next generation of high gradient RF photoguns for increased peak brightness.

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	Slides TU1PA01 [1.781 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TU1PA01
About •	Received ※ 24 August 2022 — Revised ※ 27 August 2022 — Accepted ※ 07 September 2022 — Issue date ※ 16 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPORI16	The PSI Positron Production Project	577
SUPCJO09	use link to see paper's listing under its alternate paper code
	N. Vallis, B. Auchmann, P. Craievich, M. Duda, H. Garcia Rodrigues, J. Kosse, F. Marcellini, M. Schaer, R. Zennaro PSI, Villigen PSI, Switzerland
	Funding: CHART (Swiss Accelerator Research and Technology) The PSI Positron Production project (P³ or P-cubed) is a demonstrator for a novel positron source for FCC-ee. The high current requirements of future colliders can be compromised by the extremely high positron emittance at the production target and consequent poor capture and transport to the damping ring. However, recent advances in high-temperature superconductors allow for a highly efficient matching of such an emittance through the use a solenoid around the target delivering a field over 10 T on-axis. Moreover, the emittance of the matched positron beam can be contained through large aperture RF cavities surrounded by a multi-Tesla field generated by conventional superconducting solenoids, where simulations estimate a yield higher by one order of magnitude with respect to the state-of-the-art. The goal of P³ is to demonstrate this basic principle by implementing the aforementioned solenoids into a prototype positron source based on a 6 GeV electron beam from the SwissFEL linac, two RF capture cavities and a beam diagnostics section.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI16
About •	Received ※ 15 August 2022 — Revised ※ 24 August 2022 — Accepted ※ 02 September 2022 — Issue date ※ 09 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TH2AA02	RF System Performance in the SwissFEL Linac	679
	C.D. Beard, J. Alex, H.-H. Braun, P. Craievich, Z. Geng, N. Hiller, R. Kalt, C. Kittel, T. Lippuner, T.G. Lucas, M. Pedrozzi, E. Prat, S. Reiche, T. Schietinger, W.T. Tron, D. Voulot, R. Zennaro PSI, Villigen PSI, Switzerland
	The Hard X-ray FEL machine SwissFEL at the Paul Scherrer Institut in Switzerland is commissioned and transiting to user operation smoothly. FEL operation requires stringent requirements for the beam stability at the linac output, such as the electron bunch arrival time, peak current and beam energy. Among other things, a highly stable RF system is required to guarantee the beam stability. RF performance often dominates the overall performance and availability of FELs, and for this reason the SwissFEL RF system has been designed based on the state-of-the-art technologies that have enabled excellent RF stability, resulting in an arrival time jitter of ~10 fs rms and relative beam energy stability of 10^-4 rms. This paper aims to provide an understanding of the peak performance of the RF systems and to highlight possible limitation currently faced, focusing on the S-, C- and X-Band systems.

	please see instructions how to view/control embeded videos
	Slides TH2AA02 [4.813 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TH2AA02
About •	Received ※ 20 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 02 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOJO08	RF Design of Traveling-Wave Accelerating Structures for the FCC-ee Pre-injector Complex	707
	H.W. Pommerenke, A. Grudiev, A. Latina CERN, Meyrin, Switzerland S. Bettoni, P. Craievich, J.-Y. Raguin, M. Schaer PSI, Villigen PSI, Switzerland
	Funding: This project received funding from the EU’s Horizon 2020 research program (grant No 951754), and was done under the auspices of CHART (Swiss Accelerator Research and Technology Collaboration). The linacs of the FCCee (Future Circular Electron-Positron Collider) injector complex will both provide the drive beam for positron production and accelerate nominal electron and positron beams up to 6 GeV. Several linacs comprise different traveling-wave (TW) accelerating structures fulfilling the beam dynamics and rf constraints. Notably, high-phase advance large-aperture structures accelerate the positron beam at low energies. All TW structures are rotationally symmetric for easier production. Long-range wakes are damped by HOM detuning. Operating mode and HOM parameters were calculated based on lookup tables and analytic formulas, allowing for rapidly scanning large parameter spaces. In this paper, we present both methodology and realization of the rf design of the TW structures including their pulse compressors.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOJO08
About •	Received ※ 24 August 2022 — Accepted ※ 08 September 2022 — Issue date ※ 15 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

A Discussion of Key Concepts for the Next Generation of High Brightness Injectors

324

T.G. Lucas, P. Craievich, S. Reiche
PSI, Villigen PSI, Switzerland

The production of high brightness electron beams has been key to the success of the X-ray free-electron laser (XFEL) as the new frontier in X-ray sources. The past two decades have seen the commissioning of numerous XFEL facilities, which quickly surpassed Synchrotron light sources to become the most brilliant X-ray sources. Such facilities have, so far, heavily relied on room temperature S-band RF photoguns to produce the high brightness electron bunches required for lasing, however such photoguns are reaching their peak performance limit and new methods must be investigated to continue to increase the brightness of these facilities. This talk will begin with a review of the design and performance of several electron guns currently operational in XFELs. Following will be a discussion of current efforts in continuing to increase this peak brightness including moving to cold cathode schemes and the use of very high gradients on the cathode. Finally we will describe ongoing activities at PSI to develop the next generation of high gradient RF photoguns for increased peak brightness.

please see instructions how to view/control embeded videos

Slides TU1PA01 [1.781 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TU1PA01

About •

Received ※ 24 August 2022 — Revised ※ 27 August 2022 — Accepted ※ 07 September 2022 — Issue date ※ 16 September 2022

Cite •

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

TUPORI16

The PSI Positron Production Project

577

SUPCJO09

use link to see paper's listing under its alternate paper code

N. Vallis, B. Auchmann, P. Craievich, M. Duda, H. Garcia Rodrigues, J. Kosse, F. Marcellini, M. Schaer, R. Zennaro
PSI, Villigen PSI, Switzerland

Funding: CHART (Swiss Accelerator Research and Technology)
The PSI Positron Production project (P³ or P-cubed) is a demonstrator for a novel positron source for FCC-ee. The high current requirements of future colliders can be compromised by the extremely high positron emittance at the production target and consequent poor capture and transport to the damping ring. However, recent advances in high-temperature superconductors allow for a highly efficient matching of such an emittance through the use a solenoid around the target delivering a field over 10 T on-axis. Moreover, the emittance of the matched positron beam can be contained through large aperture RF cavities surrounded by a multi-Tesla field generated by conventional superconducting solenoids, where simulations estimate a yield higher by one order of magnitude with respect to the state-of-the-art. The goal of P³ is to demonstrate this basic principle by implementing the aforementioned solenoids into a prototype positron source based on a 6 GeV electron beam from the SwissFEL linac, two RF capture cavities and a beam diagnostics section.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI16

About •

Received ※ 15 August 2022 — Revised ※ 24 August 2022 — Accepted ※ 02 September 2022 — Issue date ※ 09 September 2022

Cite •

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

TH2AA02

RF System Performance in the SwissFEL Linac

679

C.D. Beard, J. Alex, H.-H. Braun, P. Craievich, Z. Geng, N. Hiller, R. Kalt, C. Kittel, T. Lippuner, T.G. Lucas, M. Pedrozzi, E. Prat, S. Reiche, T. Schietinger, W.T. Tron, D. Voulot, R. Zennaro
PSI, Villigen PSI, Switzerland

The Hard X-ray FEL machine SwissFEL at the Paul Scherrer Institut in Switzerland is commissioned and transiting to user operation smoothly. FEL operation requires stringent requirements for the beam stability at the linac output, such as the electron bunch arrival time, peak current and beam energy. Among other things, a highly stable RF system is required to guarantee the beam stability. RF performance often dominates the overall performance and availability of FELs, and for this reason the SwissFEL RF system has been designed based on the state-of-the-art technologies that have enabled excellent RF stability, resulting in an arrival time jitter of ~10 fs rms and relative beam energy stability of 10^-4 rms. This paper aims to provide an understanding of the peak performance of the RF systems and to highlight possible limitation currently faced, focusing on the S-, C- and X-Band systems.

please see instructions how to view/control embeded videos

Slides TH2AA02 [4.813 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TH2AA02

About •

Received ※ 20 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 02 September 2022

Cite •

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

THPOJO08

RF Design of Traveling-Wave Accelerating Structures for the FCC-ee Pre-injector Complex

707

H.W. Pommerenke, A. Grudiev, A. Latina
CERN, Meyrin, Switzerland
S. Bettoni, P. Craievich, J.-Y. Raguin, M. Schaer
PSI, Villigen PSI, Switzerland

Funding: This project received funding from the EU’s Horizon 2020 research program (grant No 951754), and was done under the auspices of CHART (Swiss Accelerator Research and Technology Collaboration).
The linacs of the FCCee (Future Circular Electron-Positron Collider) injector complex will both provide the drive beam for positron production and accelerate nominal electron and positron beams up to 6 GeV. Several linacs comprise different traveling-wave (TW) accelerating structures fulfilling the beam dynamics and rf constraints. Notably, high-phase advance large-aperture structures accelerate the positron beam at low energies. All TW structures are rotationally symmetric for easier production. Long-range wakes are damped by HOM detuning. Operating mode and HOM parameters were calculated based on lookup tables and analytic formulas, allowing for rapidly scanning large parameter spaces. In this paper, we present both methodology and realization of the rf design of the TW structures including their pulse compressors.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOJO08

About •

Received ※ 24 August 2022 — Accepted ※ 08 September 2022 — Issue date ※ 15 September 2022

Cite •

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