LINAC2022 - List of Keywords (beam-loading)

Paper	Title	Other Keywords	Page
TUPOPA05	RFQ Performance During RF Conditioning and Beam Commissioning at ESS	rfq, cavity, multipactoring, MMI	418
	R. Zeng, G.S. Fedel, B. Jones, R. Miyamoto, D.J.P. Nicosia, D. Noll, A.G. Sosa, A.M. Svensson, E. Trachanas ESS, Lund, Sweden M. Baudrier CEA-DRF-IRFU, France A.C. Chauveau, M.J. Desmons, P. Hamel, O. Piquet CEA-IRFU, Gif-sur-Yvette, France F. Grespan INFN/LNL, Legnaro (PD), Italy
	RFQ at ESS has been successfully gone through RF conditioning, RF re-conditioning and low duty cycle beam commissioning. RFQ fulfills required functions and overall performance is satisfactory. RF conditioning, three RF re-conditionings after LEBT intervention and beam commissioning will be reported and RFQ performance during these periods will be described. RFQ performance in a large extent is reflected by dynamics and interactions between RF, cavity and beam. Thanks to advanced hardware capabilities and intelligent software intelligence, observation of those dynamics and interactions are done in detailed level. Analysis of those dynamics and interaction will be introduced. Some techniques to deal with challenges resulted from those dynamics and interactions will also be discussed.
	Poster TUPOPA05 [25.281 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA05
About •	Received ※ 18 August 2022 — Revised ※ 25 August 2022 — Accepted ※ 31 August 2022 — Issue date ※ 05 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPORI13	Beam Loading Simulation for Relativistic and Ultrarelativistic Beams in the Tracking Code RF-Track	cavity, simulation, accelerating-gradient, linac	569
	J. Olivares Herrador, A. Latina CERN, Meyrin, Switzerland D. Esperante Pereira, N. Fuster, B. Gimeno IFIC, Valencia, Spain B. Gimeno UVEG, Burjasot (Valencia), Spain
	Medical and industrial electron linacs can benefit from the X-band accelerating technology developed for the Compact Linear Collider (CLIC) at CERN. However, when high-intensity beams are injected in such high-gradient structures (>35 MV/m), the beam loading effect must be considered by design since this beam-cavity interaction can result in a considerable gradient reduction with respect to the unloaded case. Studying energy conservation, a partial differential equation (PDE) has been derived for injected beams, in both the relativistic and ultrarelativistic limit. Making use of this, a specific simulation package within RF-track has been developed, allowing realistic tracking of charged particle bunches under this effect regardless of their initial velocity. The performance of such tool has been assessed by reproducing previously obtained beam loaded fields in CLIC main linac and CLIC Drive-Beam linac structures. In this paper we present the analytic PDE derivation and the results of the tests.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI13
About •	Received ※ 18 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 02 September 2022 — Issue date ※ 07 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPORI20	The Impact of Beam Loading Transients on the RF System and Beam Breakup Instabilities in Energy Recovery Linacs	cavity, simulation, linac, LLRF	593
	S. Setiniyaz Lancaster University, Lancaster, United Kingdom R. Apsimon, M.J.W. Southerby Cockcroft Institute, Lancaster University, Lancaster, United Kingdom P.H. Williams STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	In multi-turn Energy Recovery Linacs (ERLs), the filling pattern describes the order that which bunches are injected into the ERL ring. The filling patterns and recombination schemes together can create various beam loading patterns/transients, which can have a big impact on the RF system, namely the cavity fundamental mode voltage, required RF power, and beam breakup instability. In this work, we demonstrate one can lower the cavity voltage fluctuation and rf power consumption by carefully choosing the right transient by using an analytical model and simulation.
	Poster TUPORI20 [0.659 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI20
About •	Received ※ 19 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 31 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TH1AA06	Low Level RF Control Algorithms for the CERN Proton LINAC4	cavity, linac, LLRF, klystron	673
	P. Baudrenghien, B. Bielawski, R.B. Borner CERN, Meyrin, Switzerland
	The CERN Linac4 Low Level RF (LLRF) uses a Linear Gaussian Regulator and an Adaptive Feed Forward to regulate the accelerating field in the cavities in the presence of strong beam loading. A Klystron Polar Loop is also implemented to compensate the RF perturbations caused by the ripples and droop in the klystron High Voltage supply. The talk presents the important parts of the regulation, shows results as the system has evolved from first prototype (2013) to operational beams (2020), and mentions some important issues encountered during the commissioning and the first years of operation, with their mitigations.

	please see instructions how to view/control embeded videos
	Slides TH1AA06 [4.183 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TH1AA06
About •	Received ※ 24 August 2022 — Revised ※ 31 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 06 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUPOPA05

RFQ Performance During RF Conditioning and Beam Commissioning at ESS

rfq, cavity, multipactoring, MMI

418

R. Zeng, G.S. Fedel, B. Jones, R. Miyamoto, D.J.P. Nicosia, D. Noll, A.G. Sosa, A.M. Svensson, E. Trachanas
ESS, Lund, Sweden
M. Baudrier
CEA-DRF-IRFU, France
A.C. Chauveau, M.J. Desmons, P. Hamel, O. Piquet
CEA-IRFU, Gif-sur-Yvette, France
F. Grespan
INFN/LNL, Legnaro (PD), Italy

RFQ at ESS has been successfully gone through RF conditioning, RF re-conditioning and low duty cycle beam commissioning. RFQ fulfills required functions and overall performance is satisfactory. RF conditioning, three RF re-conditionings after LEBT intervention and beam commissioning will be reported and RFQ performance during these periods will be described. RFQ performance in a large extent is reflected by dynamics and interactions between RF, cavity and beam. Thanks to advanced hardware capabilities and intelligent software intelligence, observation of those dynamics and interactions are done in detailed level. Analysis of those dynamics and interaction will be introduced. Some techniques to deal with challenges resulted from those dynamics and interactions will also be discussed.

Poster TUPOPA05 [25.281 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA05

About •

Received ※ 18 August 2022 — Revised ※ 25 August 2022 — Accepted ※ 31 August 2022 — Issue date ※ 05 September 2022

Cite •

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

TUPORI13

Beam Loading Simulation for Relativistic and Ultrarelativistic Beams in the Tracking Code RF-Track

cavity, simulation, accelerating-gradient, linac

569

J. Olivares Herrador, A. Latina
CERN, Meyrin, Switzerland
D. Esperante Pereira, N. Fuster, B. Gimeno
IFIC, Valencia, Spain
B. Gimeno
UVEG, Burjasot (Valencia), Spain

Medical and industrial electron linacs can benefit from the X-band accelerating technology developed for the Compact Linear Collider (CLIC) at CERN. However, when high-intensity beams are injected in such high-gradient structures (>35 MV/m), the beam loading effect must be considered by design since this beam-cavity interaction can result in a considerable gradient reduction with respect to the unloaded case. Studying energy conservation, a partial differential equation (PDE) has been derived for injected beams, in both the relativistic and ultrarelativistic limit. Making use of this, a specific simulation package within RF-track has been developed, allowing realistic tracking of charged particle bunches under this effect regardless of their initial velocity. The performance of such tool has been assessed by reproducing previously obtained beam loaded fields in CLIC main linac and CLIC Drive-Beam linac structures. In this paper we present the analytic PDE derivation and the results of the tests.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI13

About •

Received ※ 18 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 02 September 2022 — Issue date ※ 07 September 2022

Cite •

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

TUPORI20

The Impact of Beam Loading Transients on the RF System and Beam Breakup Instabilities in Energy Recovery Linacs

cavity, simulation, linac, LLRF

593

S. Setiniyaz
Lancaster University, Lancaster, United Kingdom
R. Apsimon, M.J.W. Southerby
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
P.H. Williams
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

In multi-turn Energy Recovery Linacs (ERLs), the filling pattern describes the order that which bunches are injected into the ERL ring. The filling patterns and recombination schemes together can create various beam loading patterns/transients, which can have a big impact on the RF system, namely the cavity fundamental mode voltage, required RF power, and beam breakup instability. In this work, we demonstrate one can lower the cavity voltage fluctuation and rf power consumption by carefully choosing the right transient by using an analytical model and simulation.

Poster TUPORI20 [0.659 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI20

About •

Received ※ 19 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 31 August 2022

Cite •

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

TH1AA06

Low Level RF Control Algorithms for the CERN Proton LINAC4

cavity, linac, LLRF, klystron

673

P. Baudrenghien, B. Bielawski, R.B. Borner
CERN, Meyrin, Switzerland

The CERN Linac4 Low Level RF (LLRF) uses a Linear Gaussian Regulator and an Adaptive Feed Forward to regulate the accelerating field in the cavities in the presence of strong beam loading. A Klystron Polar Loop is also implemented to compensate the RF perturbations caused by the ripples and droop in the klystron High Voltage supply. The talk presents the important parts of the regulation, shows results as the system has evolved from first prototype (2013) to operational beams (2020), and mentions some important issues encountered during the commissioning and the first years of operation, with their mitigations.

please see instructions how to view/control embeded videos

Slides TH1AA06 [4.183 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TH1AA06

About •

Received ※ 24 August 2022 — Revised ※ 31 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 06 September 2022

Cite •

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