LINAC2022 - List of Keywords (focusing)

Paper	Title	Other Keywords	Page
MOPORI03	Development of Quantum Gas Jet Beam Profile Monitor for Sub-mm Beams	electron, experiment, space-charge, 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)

MOPORI06	Improvements on the Modified Nomarski Interferometer for Measurements of Supersonic Gas Jet Density Profiles	laser, vacuum, experiment, diagnostics	235
	C. Swain, O. Apsimon, A. Salehilashkajani, C.P. Welsch, J. Wolfenden, H.D. Zhang Cockcroft Institute, Warrington, Cheshire, United Kingdom Ö. Apsimon, A. Salehilashkajani, C. Swain, C.P. Welsch, J. Wolfenden, H.D. Zhang The University of Liverpool, Liverpool, United Kingdom
	Funding: This work is supported by the AWAKE-UK phase II project funded by STFC, the STFC Cockcroft core grant No. ST/G008248/1 and the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1. For supersonic gas jet based beam profile monitors such as that developed for the High Luminosity Large Hadron Collider (HL-LHC) upgrade, density profile is a key characteristic. Due to this, non-invasive diagnostics to study the jet’s behaviour have been designed. A Nomarski interferometer was constructed to image jets 30 um to 1 mm in diameter and study changes in their density. A microscope lens has been integrated into the original interferometer system to capture phase changes on a much smaller scale than previous experiments have achieved. This contribution presents the optimisation and results gained from this interferometer.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI06
About •	Received ※ 14 August 2022 — Revised ※ 24 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 01 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPORI08	Beam Mapping Linearity Improvement in Multi-Dimensional Bunch Shape Monitor	cavity, electron, detector, operation	239
	S.V. Kutsaev, R.B. Agustsson, A.C. Araujo Martinez, A. Moro, A.Yu. Smirnov, K.V. Taletski RadiaBeam, Santa Monica, California, USA A.V. Aleksandrov, A.A. Menshov ORNL, Oak Ridge, Tennessee, USA
	Funding: This work was supported by the U.S. Department of Energy , Office of Basic Energy Sciences, under contract DE-SC0020590. RadiaBeam is developing a Bunch Shape Monitor (BSM) with improved performance that incorporates three major innovations. First, the collection efficiency is im-proved by adding a focusing field between the wire and the entrance slit. Second, a new design of an RF deflector improves beam linearity. Finally, the design is augmented with both a movable wire and a microwave deflecting cavity to add functionality and enable measuring the transverse profile as a wire scanner. In this paper, we pre-sent the design of the BSM and its sub-systems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI08
About •	Received ※ 24 August 2022 — Revised ※ 01 September 2022 — Accepted ※ 02 September 2022 — Issue date ※ 09 September 2022
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MOPORI15	Update of Adjustable PMQ Lens	quadrupole, permanent-magnet, site, dipole	262
	Y. Iwashita Kyoto University, Research Reactor Institute, Osaka, Japan Y. Fuwa JAEA/J-PARC, Tokai-mura, Japan T. Hosokai ISIR, Osaka, Japan D. Oumbarek Espinos Osaka University, Graduate School of Engineering, Osaka, Japan
	Gluckstern’s adjustable permanent magnet quadrupole (PMQ) lens based on five rings is revisited to achieve a compact focusing system for laser-accelerated beams. The first prototype was fabricated for bore diameter of 50 mm. The integrated gradient was up to 6.8 T. A new PMQ with a bore diameter of 25 mm is under fabrication based on the same geometry. While the first prototype unit was developed for the final focus magnet of the ILC, the sec-ond unit is the first doublet element for laser-accelerated electron beam focusing to be combined with this first unit. The current status of the development is reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI15
About •	Received ※ 01 September 2022 — Revised ※ 03 September 2022 — Accepted ※ 05 September 2022 — Issue date ※ 15 September 2022
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TUPOJO11	Design of Beam Focusing System with Permanent Magnet for J-PARC LINAC MEBT1	octupole, MEBT, linac, emittance	364
	Y. Fuwa, K. Moriya, T. Takayanagi JAEA/J-PARC, Tokai-mura, Japan
	Space charge compensation technology using higher-order multipole magnetic field components has been proposed to transport high-intensity charged particle beams for J-PARC LINAC MEBT1. In order to realize this compensation technology in a limited beam line space, we devised a compact-size combined-function multipole permanent magnet. This magnet can produce two multipole components at the same location on the beam line. As a first step, we have designed a magnet to simultaneously generate a fixed-strength quadrupole and an adjustable-strength octupole component using permanent magnet materials. In this magnet model, the magnetic circuit consists of two groups of magnets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOJO11
About •	Received ※ 20 August 2022 — Revised ※ 27 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 02 September 2022
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TUPOPA27	Conceptual Analysis of a Compact High Efficiency Klystron	klystron, cavity, bunching, wiggler	466
	J.P. Edelen, S.D. Webb RadiaSoft LLC, Boulder, Colorado, USA K.E. Nichols LANL, Los Alamos, New Mexico, USA
	Traditional klystron efficiencies are limited by the output electron beam harmonic current and energy spread. Increasing the amount of harmonic current produced in the klystron requires increasing the velocity bunching in the input cavity. Additional cavities may be used to improve the bunching, however they do so at additional cost and space requirements for the klystron. Moreover, at higher currents space charge counteracts this velocity bunching reducing the amount of harmonic current that can be produced. Our concept resolves these challenges by employing a new type of high-efficiency, multi-beam klystron. Our design consists of a single two-frequency input cavity, a wiggler, and an output cavity. The two-frequency input cavity approximates a linear function in time thereby increasing the harmonic content of the beam, while the wiggler provides strong longitudinal focusing to mitigate the effects of space charge. In this paper we provide the theoretical foundation for our design and present initial numerical calculations showing improved bunching from the harmonic mode and the wiggler.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA27
About •	Received ※ 14 August 2022 — Revised ※ 24 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 31 August 2022
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TUPOGE19	Status of the New Intense Heavy Ion DTL Project Alvarez 2.0 at GSI	cavity, DTL, quadrupole, operation	537
	L. Groening, T. Dettinger, X. Du, M. Heilmann, M. Kaiser, E. Merz, S. Mickat, A. Rubin, C. Xiao GSI, Darmstadt, Germany
	The Alvarez-type post-stripper DTL at GSI accelerates intense ion beams with A/q <= 8.5 from 1.4 to 11.4 MeV/u. After more than 45 years of operation it suffers from aging and its design does not meet the requirements of the upcoming FAIR project. The design of a new 10⁸ MHz Alvarez-type DTL has been completed and series components for the 55 m long DTL are under production. In preparation, a first cavity section as First of Series has been operated at nominal RF-parameters. Additionally, a prototype drift tube with internal pulsed quadrupole has been built and operated at nominal parameters successfully. High quality of copper-plating of large components and add-on parts has been achieved within the ambitious specifications. This contribution summarizes the current project status of Alvarez 2.0 at GSI and sketches the future path to completion.
	Slides TUPOGE19 [1.197 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOGE19
About •	Received ※ 18 August 2022 — Revised ※ 30 August 2022 — Accepted ※ 08 September 2022 — Issue date ※ 15 September 2022
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TUPORI19	Beam Dynamics Framework Incorporating Acceleration Used to Define the Minimum Aperture of RF Cavity For FODO-like Focusing Scheme for Proton Radiotherapy Linac	cavity, quadrupole, acceleration, lattice	589
	M.J.W. Southerby, R. Apsimon Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	Funding: Supported by the Cockcroft Institute Core Grant, ST/P002056/1. In this paper, we present a generalised analytical framework for beam dynamics studies and lattice designs, while incorporating longitudinal acceleration of bunches of charged particles. We study a ’FODO-like’ scheme, whereby we have an alternating array of focusing and defocusing quadrupoles and study how this differs from a standard FODO lattice due to acceleration. We present optimisation techniques to provide quadrupole parameters, cavity lengths, and required drift lengths under different constraints.
	Poster TUPORI19 [0.997 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI19
About •	Received ※ 23 August 2022 — Revised ※ 27 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 01 September 2022
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TUPORI30	Application of Permanent Magnets in Solenoid and Quadrupole Focusing	solenoid, quadrupole, permanent-magnet, vacuum	622
	J.D. Kaiser, A. Ateş, H. Hähnel, U. Ratzinger IAP, Frankfurt am Main, Germany
	Permanent magnets can be used to design compact high gradient focusing elements for particle accelerators. Based on cheap industrial standard Neodym permanent magnets, design studies for Solenoids and Quadrupoles are presented. The Solenoid design consists of three segments, where the outer segments possess a radial magnetization and the inner segments an axial magnetization. This increases the mean field strength in comparison to a singlet hollow cylinder solenoid. The quadrupole design consists of 16 block magnets and is designed to be rather simplistic. The casing consists of two half shells, which can be easily mounted around a beam pipe. For a quadrupole triplet configuration the influence of different geometric parameters on beam transport regarding focusing strength and emittance growth is investigated. Furthermore, a variation of the quadrupole design was mounted in vacuum in a triplet configuration. Using custom 3D-printed mounts for small raspberry pi cameras the beam could be observed inside the quadrupoles. A first prototype was constructed
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI30
About •	Received ※ 13 August 2022 — Revised ※ 17 August 2022 — Accepted ※ 02 September 2022 — Issue date ※ 04 September 2022
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THPOPA05	Status of the CLEAR User Facility at CERN and its Experiments	electron, experiment, radiation, plasma	753
	R. Corsini, W. Farabolini, A. Malyzhenkov, V. Rieker CERN, Meyrin, Switzerland P. Korysko Oxford University, Physics Department, Oxford, Oxon, United Kingdom K.N. Sjobak University of Oslo, Oslo, Norway
	The CERN Linear Accelerator for Research (CLEAR) at CERN is a versatile user facility providing a 200 MeV electron beam for accelerator R&D, irradiation studies for space, and medical applications. After successful operation in 2017-2020, CLEAR running was extended in 2021 for another 5-year period. In the paper we give a status of the facility, outlining recent progress in beam performance and hardware improvements. We report on beam operation over the last years and review the main results of experimental activities. Finally, we discuss the planned upgrades together with the proposed future experimental program.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOPA05
About •	Received ※ 24 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 01 September 2022
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THPOPA06	Methods for VHEE/FLASH Radiotherapy Studies and High Dose Rate Dosimetry at the CLEAR User Facility	electron, radiation, experiment, site	758
	P. Korysko Oxford University, Physics Department, Oxford, Oxon, United Kingdom J.J. Bateman, C.S. Robertson JAI, Oxford, United Kingdom R. Corsini, L.A. Dyks, W. Farabolini, V. Rieker CERN, Meyrin, Switzerland
	The interest for Very High Energy Electron (VHEE) radiotherapy (RT) for cancer treatment recently bloomed, given the present availability of high-gradient accelerator technology for compact, cost effective electron linacs in the 100-200 MeV energy range. Particularly promising is the so called FLASH high dose rate regime, in which cancer cells are damaged while healthy tissue is largely spared. VHEE beams are especially adapted for FLASH RT, given their penetration depth and the high beam current, needed to treat large deep seated tumors. In the CERN Linear Accelerator for Research (CLEAR) facility, a series of unique studies have been initiated on VHEE and FLASH RT issues, in collaboration with several multidisciplinary user groups. In this paper we briefly outline the activities and its main recent results, e.g. on localized dose deposition by beam focusing, and on chemical and biological test to clarify damage mechanisms. We then describe in details the dedicated systems and the techniques adopted - and in large part locally developed by the CLEAR team - in order to satisfy the user requirements, with particular attention to the crucial aspect of high dose rate dosimetry.
	Slides THPOPA06 [1.183 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOPA06
About •	Received ※ 17 August 2022 — Revised ※ 22 August 2022 — Accepted ※ 31 August 2022 — Issue date ※ 16 October 2022
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THPORI09	Design and Optimization of a 1.3 GHz Gridded Thermionic Electron Gun for High-Intensity Compact Superconducting Electron Accelerator (HICSEA)	cathode, emittance, gun, electron	851
	A.B. Kavar, A. Pathak, R. Varma IIT Mumbai, Mumbai, India
	The design and optimization of the proposed 1.3 GHz gridded thermionic electron gun aims to drive a conduction cooled superconducting electron accelerator that will be used to treat contaminants of emerging concern in water bodies. The gun geometry is Pierce-type and optimized for beam current of 1A with LaB6 as cathode material at cathode potential of -100 kV. The final optimized cathode radius and angle of inclination of the focusing electrode are found to be 1.5 mm, and 77 degree respectively. For an emittance compensation electrode, the optimized values for thickness and potential are 2 mm and -50 kV respectively, and separation between cathode and compensator is 8 mm. Beam dynamics calculations have been performed with self-developed particle tracking code that assumes space charge interactions and imported fields. The beam dynamics simulations show that with an initial bunch length of 50 ps having a bunch charge of 5 pC, the bunch length of the bunch reduces to 33 ps. The diameter, transverse and longitudinal emittance obtained are 2.8 mm, 1 mm-mrad and 5 mm-mrad respectively.
	Poster THPORI09 [1.238 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPORI09
About •	Received ※ 11 August 2022 — Revised ※ 14 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 16 September 2022
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Paper

Title

Other Keywords

Page

MOPORI03

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

electron, experiment, space-charge, 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

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MOPORI06

Improvements on the Modified Nomarski Interferometer for Measurements of Supersonic Gas Jet Density Profiles

laser, vacuum, experiment, diagnostics

235

C. Swain, O. Apsimon, A. Salehilashkajani, C.P. Welsch, J. Wolfenden, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom
Ö. Apsimon, A. Salehilashkajani, C. Swain, C.P. Welsch, J. Wolfenden, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom

Funding: This work is supported by the AWAKE-UK phase II project funded by STFC, the STFC Cockcroft core grant No. ST/G008248/1 and the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1.
For supersonic gas jet based beam profile monitors such as that developed for the High Luminosity Large Hadron Collider (HL-LHC) upgrade, density profile is a key characteristic. Due to this, non-invasive diagnostics to study the jet’s behaviour have been designed. A Nomarski interferometer was constructed to image jets 30 um to 1 mm in diameter and study changes in their density. A microscope lens has been integrated into the original interferometer system to capture phase changes on a much smaller scale than previous experiments have achieved. This contribution presents the optimisation and results gained from this interferometer.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI06

About •

Received ※ 14 August 2022 — Revised ※ 24 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 01 September 2022

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MOPORI08

Beam Mapping Linearity Improvement in Multi-Dimensional Bunch Shape Monitor

cavity, electron, detector, operation

239

S.V. Kutsaev, R.B. Agustsson, A.C. Araujo Martinez, A. Moro, A.Yu. Smirnov, K.V. Taletski
RadiaBeam, Santa Monica, California, USA
A.V. Aleksandrov, A.A. Menshov
ORNL, Oak Ridge, Tennessee, USA

Funding: This work was supported by the U.S. Department of Energy , Office of Basic Energy Sciences, under contract DE-SC0020590.
RadiaBeam is developing a Bunch Shape Monitor (BSM) with improved performance that incorporates three major innovations. First, the collection efficiency is im-proved by adding a focusing field between the wire and the entrance slit. Second, a new design of an RF deflector improves beam linearity. Finally, the design is augmented with both a movable wire and a microwave deflecting cavity to add functionality and enable measuring the transverse profile as a wire scanner. In this paper, we pre-sent the design of the BSM and its sub-systems.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI08

About •

Received ※ 24 August 2022 — Revised ※ 01 September 2022 — Accepted ※ 02 September 2022 — Issue date ※ 09 September 2022

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MOPORI15

Update of Adjustable PMQ Lens

quadrupole, permanent-magnet, site, dipole

262

Y. Iwashita
Kyoto University, Research Reactor Institute, Osaka, Japan
Y. Fuwa
JAEA/J-PARC, Tokai-mura, Japan
T. Hosokai
ISIR, Osaka, Japan
D. Oumbarek Espinos
Osaka University, Graduate School of Engineering, Osaka, Japan

Gluckstern’s adjustable permanent magnet quadrupole (PMQ) lens based on five rings is revisited to achieve a compact focusing system for laser-accelerated beams. The first prototype was fabricated for bore diameter of 50 mm. The integrated gradient was up to 6.8 T. A new PMQ with a bore diameter of 25 mm is under fabrication based on the same geometry. While the first prototype unit was developed for the final focus magnet of the ILC, the sec-ond unit is the first doublet element for laser-accelerated electron beam focusing to be combined with this first unit. The current status of the development is reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI15

About •

Received ※ 01 September 2022 — Revised ※ 03 September 2022 — Accepted ※ 05 September 2022 — Issue date ※ 15 September 2022

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TUPOJO11

Design of Beam Focusing System with Permanent Magnet for J-PARC LINAC MEBT1

octupole, MEBT, linac, emittance

364

Y. Fuwa, K. Moriya, T. Takayanagi
JAEA/J-PARC, Tokai-mura, Japan

Space charge compensation technology using higher-order multipole magnetic field components has been proposed to transport high-intensity charged particle beams for J-PARC LINAC MEBT1. In order to realize this compensation technology in a limited beam line space, we devised a compact-size combined-function multipole permanent magnet. This magnet can produce two multipole components at the same location on the beam line. As a first step, we have designed a magnet to simultaneously generate a fixed-strength quadrupole and an adjustable-strength octupole component using permanent magnet materials. In this magnet model, the magnetic circuit consists of two groups of magnets.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOJO11

About •

Received ※ 20 August 2022 — Revised ※ 27 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 02 September 2022

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TUPOPA27

Conceptual Analysis of a Compact High Efficiency Klystron

klystron, cavity, bunching, wiggler

466

J.P. Edelen, S.D. Webb
RadiaSoft LLC, Boulder, Colorado, USA
K.E. Nichols
LANL, Los Alamos, New Mexico, USA

Traditional klystron efficiencies are limited by the output electron beam harmonic current and energy spread. Increasing the amount of harmonic current produced in the klystron requires increasing the velocity bunching in the input cavity. Additional cavities may be used to improve the bunching, however they do so at additional cost and space requirements for the klystron. Moreover, at higher currents space charge counteracts this velocity bunching reducing the amount of harmonic current that can be produced. Our concept resolves these challenges by employing a new type of high-efficiency, multi-beam klystron. Our design consists of a single two-frequency input cavity, a wiggler, and an output cavity. The two-frequency input cavity approximates a linear function in time thereby increasing the harmonic content of the beam, while the wiggler provides strong longitudinal focusing to mitigate the effects of space charge. In this paper we provide the theoretical foundation for our design and present initial numerical calculations showing improved bunching from the harmonic mode and the wiggler.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA27

About •

Received ※ 14 August 2022 — Revised ※ 24 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 31 August 2022

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TUPOGE19

Status of the New Intense Heavy Ion DTL Project Alvarez 2.0 at GSI

cavity, DTL, quadrupole, operation

537

L. Groening, T. Dettinger, X. Du, M. Heilmann, M. Kaiser, E. Merz, S. Mickat, A. Rubin, C. Xiao
GSI, Darmstadt, Germany

The Alvarez-type post-stripper DTL at GSI accelerates intense ion beams with A/q <= 8.5 from 1.4 to 11.4 MeV/u. After more than 45 years of operation it suffers from aging and its design does not meet the requirements of the upcoming FAIR project. The design of a new 10⁸ MHz Alvarez-type DTL has been completed and series components for the 55 m long DTL are under production. In preparation, a first cavity section as First of Series has been operated at nominal RF-parameters. Additionally, a prototype drift tube with internal pulsed quadrupole has been built and operated at nominal parameters successfully. High quality of copper-plating of large components and add-on parts has been achieved within the ambitious specifications. This contribution summarizes the current project status of Alvarez 2.0 at GSI and sketches the future path to completion.

Slides TUPOGE19 [1.197 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOGE19

About •

Received ※ 18 August 2022 — Revised ※ 30 August 2022 — Accepted ※ 08 September 2022 — Issue date ※ 15 September 2022

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TUPORI19

Beam Dynamics Framework Incorporating Acceleration Used to Define the Minimum Aperture of RF Cavity For FODO-like Focusing Scheme for Proton Radiotherapy Linac

cavity, quadrupole, acceleration, lattice

589

M.J.W. Southerby, R. Apsimon
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

Funding: Supported by the Cockcroft Institute Core Grant, ST/P002056/1.
In this paper, we present a generalised analytical framework for beam dynamics studies and lattice designs, while incorporating longitudinal acceleration of bunches of charged particles. We study a ’FODO-like’ scheme, whereby we have an alternating array of focusing and defocusing quadrupoles and study how this differs from a standard FODO lattice due to acceleration. We present optimisation techniques to provide quadrupole parameters, cavity lengths, and required drift lengths under different constraints.

Poster TUPORI19 [0.997 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI19

About •

Received ※ 23 August 2022 — Revised ※ 27 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 01 September 2022

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TUPORI30

Application of Permanent Magnets in Solenoid and Quadrupole Focusing

solenoid, quadrupole, permanent-magnet, vacuum

622

J.D. Kaiser, A. Ateş, H. Hähnel, U. Ratzinger
IAP, Frankfurt am Main, Germany

Permanent magnets can be used to design compact high gradient focusing elements for particle accelerators. Based on cheap industrial standard Neodym permanent magnets, design studies for Solenoids and Quadrupoles are presented. The Solenoid design consists of three segments, where the outer segments possess a radial magnetization and the inner segments an axial magnetization. This increases the mean field strength in comparison to a singlet hollow cylinder solenoid. The quadrupole design consists of 16 block magnets and is designed to be rather simplistic. The casing consists of two half shells, which can be easily mounted around a beam pipe. For a quadrupole triplet configuration the influence of different geometric parameters on beam transport regarding focusing strength and emittance growth is investigated. Furthermore, a variation of the quadrupole design was mounted in vacuum in a triplet configuration. Using custom 3D-printed mounts for small raspberry pi cameras the beam could be observed inside the quadrupoles. A first prototype was constructed

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI30

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Received ※ 13 August 2022 — Revised ※ 17 August 2022 — Accepted ※ 02 September 2022 — Issue date ※ 04 September 2022

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THPOPA05

Status of the CLEAR User Facility at CERN and its Experiments

electron, experiment, radiation, plasma

753

R. Corsini, W. Farabolini, A. Malyzhenkov, V. Rieker
CERN, Meyrin, Switzerland
P. Korysko
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
K.N. Sjobak
University of Oslo, Oslo, Norway

The CERN Linear Accelerator for Research (CLEAR) at CERN is a versatile user facility providing a 200 MeV electron beam for accelerator R&D, irradiation studies for space, and medical applications. After successful operation in 2017-2020, CLEAR running was extended in 2021 for another 5-year period. In the paper we give a status of the facility, outlining recent progress in beam performance and hardware improvements. We report on beam operation over the last years and review the main results of experimental activities. Finally, we discuss the planned upgrades together with the proposed future experimental program.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOPA05

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Received ※ 24 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 01 September 2022

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THPOPA06

Methods for VHEE/FLASH Radiotherapy Studies and High Dose Rate Dosimetry at the CLEAR User Facility

electron, radiation, experiment, site

758

P. Korysko
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
J.J. Bateman, C.S. Robertson
JAI, Oxford, United Kingdom
R. Corsini, L.A. Dyks, W. Farabolini, V. Rieker
CERN, Meyrin, Switzerland

The interest for Very High Energy Electron (VHEE) radiotherapy (RT) for cancer treatment recently bloomed, given the present availability of high-gradient accelerator technology for compact, cost effective electron linacs in the 100-200 MeV energy range. Particularly promising is the so called FLASH high dose rate regime, in which cancer cells are damaged while healthy tissue is largely spared. VHEE beams are especially adapted for FLASH RT, given their penetration depth and the high beam current, needed to treat large deep seated tumors. In the CERN Linear Accelerator for Research (CLEAR) facility, a series of unique studies have been initiated on VHEE and FLASH RT issues, in collaboration with several multidisciplinary user groups. In this paper we briefly outline the activities and its main recent results, e.g. on localized dose deposition by beam focusing, and on chemical and biological test to clarify damage mechanisms. We then describe in details the dedicated systems and the techniques adopted - and in large part locally developed by the CLEAR team - in order to satisfy the user requirements, with particular attention to the crucial aspect of high dose rate dosimetry.

Slides THPOPA06 [1.183 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOPA06

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Received ※ 17 August 2022 — Revised ※ 22 August 2022 — Accepted ※ 31 August 2022 — Issue date ※ 16 October 2022

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THPORI09

Design and Optimization of a 1.3 GHz Gridded Thermionic Electron Gun for High-Intensity Compact Superconducting Electron Accelerator (HICSEA)

cathode, emittance, gun, electron

851

A.B. Kavar, A. Pathak, R. Varma
IIT Mumbai, Mumbai, India

The design and optimization of the proposed 1.3 GHz gridded thermionic electron gun aims to drive a conduction cooled superconducting electron accelerator that will be used to treat contaminants of emerging concern in water bodies. The gun geometry is Pierce-type and optimized for beam current of 1A with LaB6 as cathode material at cathode potential of -100 kV. The final optimized cathode radius and angle of inclination of the focusing electrode are found to be 1.5 mm, and 77 degree respectively. For an emittance compensation electrode, the optimized values for thickness and potential are 2 mm and -50 kV respectively, and separation between cathode and compensator is 8 mm. Beam dynamics calculations have been performed with self-developed particle tracking code that assumes space charge interactions and imported fields. The beam dynamics simulations show that with an initial bunch length of 50 ps having a bunch charge of 5 pC, the bunch length of the bunch reduces to 33 ps. The diameter, transverse and longitudinal emittance obtained are 2.8 mm, 1 mm-mrad and 5 mm-mrad respectively.

Poster THPORI09 [1.238 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPORI09

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Received ※ 11 August 2022 — Revised ※ 14 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 16 September 2022

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