HB2023 - List of Keywords (solenoid)

Paper	Title	Other Keywords	Page
WEC3I1	Self-Consistent Injection Painting for Space Charge Mitigation	space-charge, injection, emittance, experiment	258
	N.J. Evans, V.S. Morozov ORNL RAD, Oak Ridge, Tennessee, USA T.V. Gorlov, A.M. Hoover ORNL, Oak Ridge, Tennessee, USA
	Funding: This work was conducted at UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy, with partial funding provided by Field Work Proposal ORNL-ERKCS41. I will present results of experiments at the Spallation Neutron Source to implement a method of phase space painting we refer to as ¿eigenpainting¿, in which beam is injected along one eigenvector of the transfer matrix of a ring with full coupling. The method and resultant distribution were initially proposed by Danilov almost to linearize the space charge force, minimizing space charge tune spread. In the theoretically ideal case this so-called Danilov distribution has uniform charge distribution, elliptical envelope in real-space, and a vanishing 4D transverse emittance. Such a beam can be maintained throughout injection. The Danilov distribution has implications for increasing beam intensity beyond the conventional space charge limit through a reduction of both tune spread and shift, and increasing collider performance. This talk will present current limits on beam quality, and details of the preparation of the optics in the SNS accumulator ring, including the installation of new solenoid magnets. The status of experiments to improve beam quality and characterize the interesting dynamical implications of the defining features of the Danilov distribution will also be discussed.
	Slides WEC3I1 [2.687 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC3I1
About •	Received ※ 28 September 2023 — Revised ※ 10 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 23 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEA4I2	Linac4 Source and Low Energy Experience and Challenges	rfq, emittance, linac, simulation	290
	E. Sargsyan, G. Bellodi, F.D.L. Di Lorenzo, J. Etxebarria, J.-B. Lallement, A.M. Lombardi, M. O’Neil CERN, Meyrin, Switzerland
	At the end of Long Shutdown 2 (LS2), in 2020 Linac4 became the new injector of CERN’s proton accelerator complex. The previous version of the Linac4 H⁻ ion source (IS03), produced an operational pulsed peak beam current of 35 mA, resulting in 27 mA after the Radio-Frequency Quadrupole (RFQ). This limited transmission was mainly due to the extracted beam emittance exceeding the acceptance of the RFQ. A new geometry of the Linac4 source extraction electrodes has been developed with the aim of decreasing the extracted beam emittance and increasing the transmission through the RFQ. The new source (IS04) has been studied and thoroughly tested at the Linac4 source test stand. At the start of the 2023 run, the IS04 was installed as operational source in the Linac4 tunnel and is being successfully used for operation with 27 mA peak current after the RFQ. During high-intensity tests, the source, the linac, and the transfer-line to the Proton Synchrotron Booster (PSB) were also tested with a peak beam current of up to 50 mA from the source resulting in 35 mA at the PSB injection. This paper discusses the recent developments, tests, and future plans for the Linac4 H⁻ ion source.
	Slides WEA4I2 [2.217 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA4I2
About •	Received ※ 27 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 29 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THA2C1	Measurement of Transverse Beam Emittance for a High-Intensity Proton Injector	space-charge, emittance, simulation, beam-transport	363
	D.-H. Kim, H.S. Kim, H.-J. Kwon, S. Lee KOMAC, KAERI, Gyeongju, Republic of Korea
	Funding: This work was supported through "KOMAC operation fund" of KAERI by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (KAERI-524320-23) We propose a simple and fast diagnostics method for the transverse beam emittance using a solenoid magnet. The solenoid scan data is analyzed employing the hard edge solenoid model and thick lens approximation. The analytical method is validated by beam dynamics simulations with varying input beam parameters. To address the space charge effect in a simplified manner, the space charge force is linearized and incorporated between segments of the drift-solenoid transfer matrix. For intense hadron injectors with higher beam current accounting for space charge prove to be more effective for correction. Building upon the method validated through beam simulation, experiments are conducted on space charge compensation at the beam test stand in the Korea Multipurpose Accelerator Complex (KOMAC). In a constant ion source operating condition, beam emittance is measured from solenoid scans while varying the flow rate of krypton gas injection. Notable shifts are observed in transverse beam emittance attributable to krypton gas injection, implying some optimal gas flow rate for mitigating emittance growth.
	Slides THA2C1 [3.438 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THA2C1
About •	Received ※ 23 October 2023 — Revised ※ 28 October 2023 — Accepted ※ 30 October 2023 — Issued ※ 20 November 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THA2C3	Periodic Solution for Transport of Intense and Coupled Coasting Beams Through Quadrupole Channels	coupling, lattice, space-charge, quadrupole	372
	C. Xiao, L. Groening GSI, Darmstadt, Germany
	Imposing defined spinning to a particle beam increases its stability against perturbations from space charge [Y.-L. Cheon et al., Effects of beam spinning on the fourth-order particle resonance of 3D bunched beams in high intensity linear accelerators, Phys. Rev. Accel. & Beams 25, 064002 (2022)]. In order to fully explore this potential, proper matching of intense coupled beams along regular lattices is mandatory. Herein, a novel procedure assuming matched transport is described and bench-marked through simulations. The concept of matched transport along periodic lattices has been extended from uncoupled beams to those with considerable coupling between the two transverse degrees of freedom. For coupled beams, matching means extension of cell-to-cell periodicity from just transverse envelopes to the coupled beam moments and to quantities being derived from these.
	Slides THA2C3 [1.649 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THA2C3
About •	Received ※ 25 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 19 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP08	Simulation Studies on the Low Energy Beam Transfer (LEBT) System of the ISIS Neutron Spallation Source	ion-source, rfq, LEBT, space-charge	454
	S.A. Ahmadiannamin, D.C. Faircloth, S.R. Lawrie, A.P. Letchford, T.M. Sarmento, O.A. Tarvainen STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The transmission efficiency and beam dynamic parameters of the low-energy beam transfer (LEBT) section of proton accelerators, serving as a neutron spallation source, have a critical impact on beam loss in subsequent sections of the linear accelerator. Due to variations and mismatches, the beam parameters at the entrance of the radio-frequency quadrupole (RFQ) change, significantly affecting the transmission efficiency of the RFQ and the matching between RFQ and drift tube linac (DTL) structures. Recognizing the importance of this concept, particle-in-cell studies were conducted to optimize the LEBT section of the ISIS accelerator. This study presents the results of simulations.
	Poster THBP08 [1.081 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP08
About •	Received ※ 01 October 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 30 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

WEC3I1

Self-Consistent Injection Painting for Space Charge Mitigation

space-charge, injection, emittance, experiment

258

N.J. Evans, V.S. Morozov
ORNL RAD, Oak Ridge, Tennessee, USA
T.V. Gorlov, A.M. Hoover
ORNL, Oak Ridge, Tennessee, USA

Funding: This work was conducted at UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy, with partial funding provided by Field Work Proposal ORNL-ERKCS41.
I will present results of experiments at the Spallation Neutron Source to implement a method of phase space painting we refer to as ¿eigenpainting¿, in which beam is injected along one eigenvector of the transfer matrix of a ring with full coupling. The method and resultant distribution were initially proposed by Danilov almost to linearize the space charge force, minimizing space charge tune spread. In the theoretically ideal case this so-called Danilov distribution has uniform charge distribution, elliptical envelope in real-space, and a vanishing 4D transverse emittance. Such a beam can be maintained throughout injection. The Danilov distribution has implications for increasing beam intensity beyond the conventional space charge limit through a reduction of both tune spread and shift, and increasing collider performance. This talk will present current limits on beam quality, and details of the preparation of the optics in the SNS accumulator ring, including the installation of new solenoid magnets. The status of experiments to improve beam quality and characterize the interesting dynamical implications of the defining features of the Danilov distribution will also be discussed.

Slides WEC3I1 [2.687 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC3I1

About •

Received ※ 28 September 2023 — Revised ※ 10 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 23 October 2023

Cite •

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

WEA4I2

Linac4 Source and Low Energy Experience and Challenges

rfq, emittance, linac, simulation

290

E. Sargsyan, G. Bellodi, F.D.L. Di Lorenzo, J. Etxebarria, J.-B. Lallement, A.M. Lombardi, M. O’Neil
CERN, Meyrin, Switzerland

At the end of Long Shutdown 2 (LS2), in 2020 Linac4 became the new injector of CERN’s proton accelerator complex. The previous version of the Linac4 H⁻ ion source (IS03), produced an operational pulsed peak beam current of 35 mA, resulting in 27 mA after the Radio-Frequency Quadrupole (RFQ). This limited transmission was mainly due to the extracted beam emittance exceeding the acceptance of the RFQ. A new geometry of the Linac4 source extraction electrodes has been developed with the aim of decreasing the extracted beam emittance and increasing the transmission through the RFQ. The new source (IS04) has been studied and thoroughly tested at the Linac4 source test stand. At the start of the 2023 run, the IS04 was installed as operational source in the Linac4 tunnel and is being successfully used for operation with 27 mA peak current after the RFQ. During high-intensity tests, the source, the linac, and the transfer-line to the Proton Synchrotron Booster (PSB) were also tested with a peak beam current of up to 50 mA from the source resulting in 35 mA at the PSB injection. This paper discusses the recent developments, tests, and future plans for the Linac4 H⁻ ion source.

Slides WEA4I2 [2.217 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA4I2

About •

Received ※ 27 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 29 October 2023

Cite •

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

THA2C1

Measurement of Transverse Beam Emittance for a High-Intensity Proton Injector

space-charge, emittance, simulation, beam-transport

363

D.-H. Kim, H.S. Kim, H.-J. Kwon, S. Lee
KOMAC, KAERI, Gyeongju, Republic of Korea

Funding: This work was supported through "KOMAC operation fund" of KAERI by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (KAERI-524320-23)
We propose a simple and fast diagnostics method for the transverse beam emittance using a solenoid magnet. The solenoid scan data is analyzed employing the hard edge solenoid model and thick lens approximation. The analytical method is validated by beam dynamics simulations with varying input beam parameters. To address the space charge effect in a simplified manner, the space charge force is linearized and incorporated between segments of the drift-solenoid transfer matrix. For intense hadron injectors with higher beam current accounting for space charge prove to be more effective for correction. Building upon the method validated through beam simulation, experiments are conducted on space charge compensation at the beam test stand in the Korea Multipurpose Accelerator Complex (KOMAC). In a constant ion source operating condition, beam emittance is measured from solenoid scans while varying the flow rate of krypton gas injection. Notable shifts are observed in transverse beam emittance attributable to krypton gas injection, implying some optimal gas flow rate for mitigating emittance growth.

Slides THA2C1 [3.438 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THA2C1

About •

Received ※ 23 October 2023 — Revised ※ 28 October 2023 — Accepted ※ 30 October 2023 — Issued ※ 20 November 2023

Cite •

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

THA2C3

Periodic Solution for Transport of Intense and Coupled Coasting Beams Through Quadrupole Channels

coupling, lattice, space-charge, quadrupole

372

C. Xiao, L. Groening
GSI, Darmstadt, Germany

Imposing defined spinning to a particle beam increases its stability against perturbations from space charge [Y.-L. Cheon et al., Effects of beam spinning on the fourth-order particle resonance of 3D bunched beams in high intensity linear accelerators, Phys. Rev. Accel. & Beams 25, 064002 (2022)]. In order to fully explore this potential, proper matching of intense coupled beams along regular lattices is mandatory. Herein, a novel procedure assuming matched transport is described and bench-marked through simulations. The concept of matched transport along periodic lattices has been extended from uncoupled beams to those with considerable coupling between the two transverse degrees of freedom. For coupled beams, matching means extension of cell-to-cell periodicity from just transverse envelopes to the coupled beam moments and to quantities being derived from these.

Slides THA2C3 [1.649 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THA2C3

About •

Received ※ 25 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 19 October 2023

Cite •

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

THBP08

Simulation Studies on the Low Energy Beam Transfer (LEBT) System of the ISIS Neutron Spallation Source

ion-source, rfq, LEBT, space-charge

454

S.A. Ahmadiannamin, D.C. Faircloth, S.R. Lawrie, A.P. Letchford, T.M. Sarmento, O.A. Tarvainen
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The transmission efficiency and beam dynamic parameters of the low-energy beam transfer (LEBT) section of proton accelerators, serving as a neutron spallation source, have a critical impact on beam loss in subsequent sections of the linear accelerator. Due to variations and mismatches, the beam parameters at the entrance of the radio-frequency quadrupole (RFQ) change, significantly affecting the transmission efficiency of the RFQ and the matching between RFQ and drift tube linac (DTL) structures. Recognizing the importance of this concept, particle-in-cell studies were conducted to optimize the LEBT section of the ISIS accelerator. This study presents the results of simulations.

Poster THBP08 [1.081 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP08

About •

Received ※ 01 October 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 30 October 2023

Cite •

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