LINAC2022 - List of Keywords (space-charge)

Paper	Title	Other Keywords	Page
MOPOPA16	UNILAC Heavy Ion Beam Operation at FAIR Intensities	emittance, heavy-ion, brilliance, injection	102
	W.A. Barth, M. Miski-Oglu, U. Scheeler, H. Vormann, M. Vossberg, S. Yaramyshev GSI, Darmstadt, Germany M. Miski-Oglu HIM, Mainz, Germany
	The GSI-UNILAC as well as the heavy ion synchrotron SIS18 will serve as a high current heavy ion injector for the FAIR synchrotron SIS100. In the context of an advanced machine investigation program acceleration and transport of space charge dominated argon beam inside entire UNILAC have been explored. The conducted high current argon beam measurements throughout the UNILAC-poststripper and transferline to SIS18 show a transversal emittance growth of only 35% for the design current of 7 emA (40Ar¹⁰⁺). By horizontal collimation of the UNILAC beam emittance, the space charge limit could be reached at slightly lower pulse currents, but accordingly longer injection times. Further improvements in brilliance can be expected from the planned upgrade measures, in particular on the high-current injector linac.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOPA16
About •	Received ※ 19 August 2022 — Revised ※ 22 August 2022 — Accepted ※ 26 August 2022 — Issue date ※ 01 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPORI03	Development of Quantum Gas Jet Beam Profile Monitor for Sub-mm Beams	electron, experiment, focusing, factory	223
	N. Kumar, O. Stringer, C.P. Welsch, J. Wolfenden, H.D. Zhang The University of Liverpool, Liverpool, United Kingdom N. Kumar, C.P. Welsch, J. Wolfenden, H.D. Zhang Cockcroft Institute, Warrington, Cheshire, United Kingdom I. Maltusch FH Aachen, Jülich, Germany
	Funding: This work is supported by the STFC grants ST/W000687/1 and ST/W002159/1, InnovateUK Germinator 10004615, HL-LHC-UK project funded by STFC and CERN and the STFC Cockcroft core grant No. ST/G008248/1. The development work of a high-resolution quantum gas jet beam profile monitor for highly energetic sub-mm particle beams is in progress at the Cockcroft Institute (CI), UK. This device is designed on the principle of detecting the secondary ions from the ionisation induced in the interaction between the quantum gas jet and charged particle beams. This monitor aims to generate an intense gas jet with a diameter of less than 100 µm, which can ultimately lead to superior position resolution and high signal intensity resulting from a strongly focused quantum gas jet. This is done by exploiting the quantum wave feature of the neutral gas atoms to generate an interference pattern with a single maximum acting as an ultra-thin gas jet using an ’atom sieve’ which is similar to the light focusing with a Fresnel zone plate. This device will be minimally interceptive and will work analogously to a mechanical wire scanner. This contribution gives a general overview of the design, working principle of the monitor and experimental results obtained from the electron beam profile measurements carried out at the Cockcroft Institute.
	Poster MOPORI03 [1.581 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI03
About •	Received ※ 13 August 2022 — Revised ※ 16 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 01 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOPA04	First Beam Matching and Transmission Studies on the ESS RFQ	rfq, LEBT, MMI, emittance	414
	D. Noll, R.A. Baron, C.S. Derrez, E.M. Donegani, M. Eshraqi, F. Grespan, H. Hassanzadegan, B. Jones, Y. Levinsen, N. Milas, R. Miyamoto, D.C. Plostinar, A.G. Sosa, R. Zeng ESS, Lund, Sweden A.C. Chauveau, O. Piquet CEA-IRFU, Gif-sur-Yvette, France
	The European Spallation Source will be driven by a 5 MW linear accelerator, producing 2.86 ms long proton beam pulses with a peak current of 62.5 mA at 14 Hz. Following the source commissioning in 2018 and 2019, the RFQ was successfully conditioned and subsequently commissioned with beam in 2021. In this paper, we will present results of studies on beam matching to the RFQ, both for low and high current beam modes, and will compare these results to model predictions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA04
About •	Received ※ 26 August 2022 — Accepted ※ 05 September 2022 — Issue date ※ 05 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOGE20	Observation of Current-Driven Features of 2.5 Mev Ion Bunch With Complete and Efficient 5D Measurements at the SNS Beam Test Facility	rfq, quadrupole, dipole, simulation	541
	K.J. Ruisard, A.V. Aleksandrov, S.M. Cousineau, A.M. Hoover, A.P. Zhukov ORNL, Oak Ridge, Tennessee, USA
	Funding: Work supported by U.S. Department of Energy, Office of Science, High Energy Physics. Authored by UT- Battelle, LLC under DOE Contract No. DE-AC05-00OR22725. The SNS Beam Test Facility research program is focused detailed studies of beam distributions for medium-energy ion beams, with the goal of reconstructing realistic 6D bunch distributions to enable halo prediction. For complete characterization of the initial distribution, scan time scales exponentially with scan dimension. Currently, a full 6D measurement with ~10 points across most dimensions requires 30 hours. However, measurement of the 5D distribution f(x, x’,y,y’,w) can be done very rapidly using a hybrid slit/screen method. This approach requires ~4 hours to obtain at least 32 points/dimension, with very high resolution (0.5 keV) in the energy distribution. This presentation reports on the approach and results for 5D characterization of the initial RFQ-formed bunch. This includes higher-resolution views of previously reported transverse-longitudinal dependence and additional interplane dependencies that were not previously reported.
	Slides TUPOGE20 [1.230 MB]
	Poster TUPOGE20 [1.406 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOGE20
About •	Received ※ 25 August 2022 — Revised ※ 30 August 2022 — Accepted ※ 04 September 2022 — Issue date ※ 16 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPORI06	Harmonic Bunch Formation and Optional RFQ Injection	rfq, emittance, injection, cavity	559
	E. Sunar, U. Ratzinger, M. Syha, R. Tiede IAP, Frankfurt am Main, Germany
	With the aim of reduced beam emittances, a pre-bunching concept into an RFQ or a DTL has been developed. The structure has been designed by using a two harmonics double drift buncher which consists of two bunchers: the first one is driven by a fundamental frequency whereas the other is ex- cited with the second harmonic including a drift in between. This well-known "Harmonic Double-Drift-Buncher" is rein- vestigated under space charge conditions for RFQ, cyclotron, and for direct DTL-injection. There are significant benefits for this design such as to catch as many particles as possible from a dc beam into the longitudinal linac acceptance, or to reduce/optimize by up to an order of magnitude the lon- gitudinal emittance for low and medium beam currents. In accordance to these advantages, a new multi-particle track- ing beam dynamics code has been developed which is called "Bunch Creation from a DC beam - BCDC". In this paper we present this new code and some stimulating examples.
	Poster TUPORI06 [28.234 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI06
About •	Received ※ 14 August 2022 — Revised ※ 24 August 2022 — Accepted ※ 31 August 2022 — Issue date ※ 05 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPORI26	Longitudinal Beam Dynamics in Array of Equidistant Multicell Cavities	cavity, linac, acceleration, emittance	609
	Y.K. Batygin LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by US DOE under contract 89233218CNA000001 Linear accelerators containing the sequence of independently phase cavities with constant geometrical velocity along each cavity are widely used in practice. The chain of cavities with identical cell length is utilized within a certain beam velocity range, with subsequent transformation to the next chain with higher cavity velocity. Design and analysis of beam dynamics in this type of accelerators are usually performed using numerical simulations. In the present paper, we provide an analytical treatment of beam dynamics in such linacs. Expressions connecting beam energy gain and phase slippage along the cavity are implemented. The dynamics of the beam around the reference trajectory along the accelerator and matched beam conditions are discussed.
	Poster TUPORI26 [1.718 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI26
About •	Received ※ 20 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 02 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOJO26	Conceptual Design of the PERLE Injector	emittance, linac, dipole, quadrupole	743
	B. Hounsell, M. Klein, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom B. Hounsell, B.L. Militsyn, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom B. Hounsell, W. Kaabi Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France B.L. Militsyn STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Energy Recovery Linacs such as PERLE require high average current high brightness beams. This sets particular requirements on the kind of injectors that they can use as the injectors must be capable of producing bunches at MHz repetition rates, compressing the bunches to the specified value and transporting those bunches while they are still in the space charge dominated regime into the main ERL all while keeping the emittance low. In particular, PERLE will require a 20 mA beam consisting of 500 pC bunches with a repetition rate of 40 MHz. These bunches will be required to have rms lengths of 3mm, a total beam energy of 7 MeV, appropriate Twiss parameters to match them to the main loop and transverse emittances of < 6 mm mrad. In this paper, a DC gun based injector capable of meeting this specification will be presented with beam dynamics simulation showing the behaviour of the beam from the photocathode to the exit of the first main linac pass. The beam dynamics challenges will be discussed in terms of both the transverse emittance growth and the sources of non-linearity in the longitudinal phase space.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOJO26
About •	Received ※ 20 August 2022 — Revised ※ 24 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 15 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPOPA16

UNILAC Heavy Ion Beam Operation at FAIR Intensities

emittance, heavy-ion, brilliance, injection

102

W.A. Barth, M. Miski-Oglu, U. Scheeler, H. Vormann, M. Vossberg, S. Yaramyshev
GSI, Darmstadt, Germany
M. Miski-Oglu
HIM, Mainz, Germany

The GSI-UNILAC as well as the heavy ion synchrotron SIS18 will serve as a high current heavy ion injector for the FAIR synchrotron SIS100. In the context of an advanced machine investigation program acceleration and transport of space charge dominated argon beam inside entire UNILAC have been explored. The conducted high current argon beam measurements throughout the UNILAC-poststripper and transferline to SIS18 show a transversal emittance growth of only 35% for the design current of 7 emA (40Ar¹⁰⁺). By horizontal collimation of the UNILAC beam emittance, the space charge limit could be reached at slightly lower pulse currents, but accordingly longer injection times. Further improvements in brilliance can be expected from the planned upgrade measures, in particular on the high-current injector linac.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOPA16

About •

Received ※ 19 August 2022 — Revised ※ 22 August 2022 — Accepted ※ 26 August 2022 — Issue date ※ 01 September 2022

Cite •

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

MOPORI03

Development of Quantum Gas Jet Beam Profile Monitor for Sub-mm Beams

electron, experiment, focusing, factory

223

N. Kumar, O. Stringer, C.P. Welsch, J. Wolfenden, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom
N. Kumar, C.P. Welsch, J. Wolfenden, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom
I. Maltusch
FH Aachen, Jülich, Germany

Funding: This work is supported by the STFC grants ST/W000687/1 and ST/W002159/1, InnovateUK Germinator 10004615, HL-LHC-UK project funded by STFC and CERN and the STFC Cockcroft core grant No. ST/G008248/1.
The development work of a high-resolution quantum gas jet beam profile monitor for highly energetic sub-mm particle beams is in progress at the Cockcroft Institute (CI), UK. This device is designed on the principle of detecting the secondary ions from the ionisation induced in the interaction between the quantum gas jet and charged particle beams. This monitor aims to generate an intense gas jet with a diameter of less than 100 µm, which can ultimately lead to superior position resolution and high signal intensity resulting from a strongly focused quantum gas jet. This is done by exploiting the quantum wave feature of the neutral gas atoms to generate an interference pattern with a single maximum acting as an ultra-thin gas jet using an ’atom sieve’ which is similar to the light focusing with a Fresnel zone plate. This device will be minimally interceptive and will work analogously to a mechanical wire scanner. This contribution gives a general overview of the design, working principle of the monitor and experimental results obtained from the electron beam profile measurements carried out at the Cockcroft Institute.

Poster MOPORI03 [1.581 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI03

About •

Received ※ 13 August 2022 — Revised ※ 16 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 01 September 2022

Cite •

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

TUPOPA04

First Beam Matching and Transmission Studies on the ESS RFQ

rfq, LEBT, MMI, emittance

414

D. Noll, R.A. Baron, C.S. Derrez, E.M. Donegani, M. Eshraqi, F. Grespan, H. Hassanzadegan, B. Jones, Y. Levinsen, N. Milas, R. Miyamoto, D.C. Plostinar, A.G. Sosa, R. Zeng
ESS, Lund, Sweden
A.C. Chauveau, O. Piquet
CEA-IRFU, Gif-sur-Yvette, France

The European Spallation Source will be driven by a 5 MW linear accelerator, producing 2.86 ms long proton beam pulses with a peak current of 62.5 mA at 14 Hz. Following the source commissioning in 2018 and 2019, the RFQ was successfully conditioned and subsequently commissioned with beam in 2021. In this paper, we will present results of studies on beam matching to the RFQ, both for low and high current beam modes, and will compare these results to model predictions.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA04

About •

Received ※ 26 August 2022 — Accepted ※ 05 September 2022 — Issue date ※ 05 September 2022

Cite •

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

TUPOGE20

Observation of Current-Driven Features of 2.5 Mev Ion Bunch With Complete and Efficient 5D Measurements at the SNS Beam Test Facility

rfq, quadrupole, dipole, simulation

541

K.J. Ruisard, A.V. Aleksandrov, S.M. Cousineau, A.M. Hoover, A.P. Zhukov
ORNL, Oak Ridge, Tennessee, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, High Energy Physics. Authored by UT- Battelle, LLC under DOE Contract No. DE-AC05-00OR22725.
The SNS Beam Test Facility research program is focused detailed studies of beam distributions for medium-energy ion beams, with the goal of reconstructing realistic 6D bunch distributions to enable halo prediction. For complete characterization of the initial distribution, scan time scales exponentially with scan dimension. Currently, a full 6D measurement with ~10 points across most dimensions requires 30 hours. However, measurement of the 5D distribution f(x, x’,y,y’,w) can be done very rapidly using a hybrid slit/screen method. This approach requires ~4 hours to obtain at least 32 points/dimension, with very high resolution (0.5 keV) in the energy distribution. This presentation reports on the approach and results for 5D characterization of the initial RFQ-formed bunch. This includes higher-resolution views of previously reported transverse-longitudinal dependence and additional interplane dependencies that were not previously reported.

Slides TUPOGE20 [1.230 MB]

Poster TUPOGE20 [1.406 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOGE20

About •

Received ※ 25 August 2022 — Revised ※ 30 August 2022 — Accepted ※ 04 September 2022 — Issue date ※ 16 September 2022

Cite •

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

TUPORI06

Harmonic Bunch Formation and Optional RFQ Injection

rfq, emittance, injection, cavity

559

E. Sunar, U. Ratzinger, M. Syha, R. Tiede
IAP, Frankfurt am Main, Germany

With the aim of reduced beam emittances, a pre-bunching concept into an RFQ or a DTL has been developed. The structure has been designed by using a two harmonics double drift buncher which consists of two bunchers: the first one is driven by a fundamental frequency whereas the other is ex- cited with the second harmonic including a drift in between. This well-known "Harmonic Double-Drift-Buncher" is rein- vestigated under space charge conditions for RFQ, cyclotron, and for direct DTL-injection. There are significant benefits for this design such as to catch as many particles as possible from a dc beam into the longitudinal linac acceptance, or to reduce/optimize by up to an order of magnitude the lon- gitudinal emittance for low and medium beam currents. In accordance to these advantages, a new multi-particle track- ing beam dynamics code has been developed which is called "Bunch Creation from a DC beam - BCDC". In this paper we present this new code and some stimulating examples.

Poster TUPORI06 [28.234 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI06

About •

Received ※ 14 August 2022 — Revised ※ 24 August 2022 — Accepted ※ 31 August 2022 — Issue date ※ 05 September 2022

Cite •

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

TUPORI26

Longitudinal Beam Dynamics in Array of Equidistant Multicell Cavities

cavity, linac, acceleration, emittance

609

Y.K. Batygin
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by US DOE under contract 89233218CNA000001
Linear accelerators containing the sequence of independently phase cavities with constant geometrical velocity along each cavity are widely used in practice. The chain of cavities with identical cell length is utilized within a certain beam velocity range, with subsequent transformation to the next chain with higher cavity velocity. Design and analysis of beam dynamics in this type of accelerators are usually performed using numerical simulations. In the present paper, we provide an analytical treatment of beam dynamics in such linacs. Expressions connecting beam energy gain and phase slippage along the cavity are implemented. The dynamics of the beam around the reference trajectory along the accelerator and matched beam conditions are discussed.

Poster TUPORI26 [1.718 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI26

About •

Received ※ 20 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 02 September 2022

Cite •

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

THPOJO26

Conceptual Design of the PERLE Injector

emittance, linac, dipole, quadrupole

743

B. Hounsell, M. Klein, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
B. Hounsell, B.L. Militsyn, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
B. Hounsell, W. Kaabi
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
B.L. Militsyn
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Energy Recovery Linacs such as PERLE require high average current high brightness beams. This sets particular requirements on the kind of injectors that they can use as the injectors must be capable of producing bunches at MHz repetition rates, compressing the bunches to the specified value and transporting those bunches while they are still in the space charge dominated regime into the main ERL all while keeping the emittance low. In particular, PERLE will require a 20 mA beam consisting of 500 pC bunches with a repetition rate of 40 MHz. These bunches will be required to have rms lengths of 3mm, a total beam energy of 7 MeV, appropriate Twiss parameters to match them to the main loop and transverse emittances of < 6 mm mrad. In this paper, a DC gun based injector capable of meeting this specification will be presented with beam dynamics simulation showing the behaviour of the beam from the photocathode to the exit of the first main linac pass. The beam dynamics challenges will be discussed in terms of both the transverse emittance growth and the sources of non-linearity in the longitudinal phase space.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOJO26

About •

Received ※ 20 August 2022 — Revised ※ 24 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 15 September 2022

Cite •

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