LINAC2022 - List of Keywords (detector)

Paper	Title	Other Keywords	Page
MOPOJO11	Challenges for High-Energy X-Ray Security Screening Linacs	linac, electron, cavity, photon	50
	M. Jenkins, J. Ollier, M.G. Procter Rapiscan Systems Ltd, Stoke-on-Trent, United Kingdom
	X-ray based Cargo and Vehicle Inspection (CVI) systems are used for security and customs inspections at a variety of locations. To provide the maximum flexibility many users require mobile CVI systems to allow vehicles to be screened efficiently for threats and contraband. The need for mobile systems means that the linear accelerator, and ancillary systems, used to generate the x-rays must be compact, rugged, and reliable. These systems must meet image performance tests specified by American National Standards Institute (ANSI) and the International Electrotechnical Commission (IEC). The IEC also defines a standard for material discrimination. The requirements of these standards mean that the x-ray output produced by the linac needs to be consistent during and between scans, with the stability and repeatability of the output being critical. The tolerances on the linac output to meet the performance standards combined with the need for a compact system gives an unusual challenge for the linac design. A review of how different stability measures impact the performance tests is presented. This is compared to current technologies and possible future linacs used for mobile CVI systems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOJO11
About •	Received ※ 24 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 01 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOPA11	Laser-to-RF Synchronisation Drift Compensation for the CLARA test facility	laser, FEM, electron, timing	87
	J. Henderson, A.J. Moss, E.W. Snedden STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom A.C. Dexter Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	Femtosecond synchronisation between charged particle beams and external laser systems is a significant challenge for modern particle accelerators. To achieve femtosecond synchronisation of the CLARA electron beam and end user laser systems will require tight synchronisation of several accelerator subsystems. This paper reports on a method to compensate for environmentally driven long-term drift in Laser-RF phase detection systems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOPA11
About •	Received ※ 22 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 15 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOGE25	Rf Measurement and Characterisation of European Spallation Source Cavities at UKRI-STFC Daresbury Laboratory and DESY	cavity, radiation, cryomodule, MMI	212
	P.A. Smith, A.E.T. Akintola, K.D. Dumbell, M.J. Ellis, S. Hitchen, P.C. Hornickel, C.R. Jenkins, A.J. May, P.A. McIntosh, K.J. Middleman, A.J. Moss, S.M. Pattalwar, M.D. Pendleton, J.O.W. Poynton, A.E. Wheelhouse, S. Wilde STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G. Jones, M. Lowe, D.A. Mason, G. Miller, J. Mutch, A. Oates, J.T.G. Wilson STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom K.J. Middleman Cockcroft Institute, Warrington, Cheshire, United Kingdom D. Reschke, L. Steder, M. Wiencek DESY, Hamburg, Germany
	The Accelerator Science and Technology Centre (ASTeC) is responsible for delivering 88 High Beta (HB) cavities as part of the European Spallation Source (ESS) facility in Sweden. The bulk Niobium Superconducting Radio Frequency (SRF) cavities operate at 704 MHz. They have been fabricated in industry and are currently being tested at Daresbury Laboratory and Deutsches Elektronen-Synchrotron (DESY). They will then be delivered to Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA) Saclay, France for integration into cryomodules. To date 50 cavities have been conditioned and evaluated and 36 cavities have been delivered to CEA. This paper discusses the experiences and testing of the cavities performed to date at both sites
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE25
About •	Received ※ 24 August 2022 — Revised ※ 29 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 04 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPORI01	A Multi-Camera System for Tomographic Beam Diagnostics	vacuum, controls, synchrotron, diagnostics	215
	A. Ateş, G. Blank, H. Hähnel, U. Ratzinger IAP, Frankfurt am Main, Germany
	A prototype of a beam-induced residual gas fluorescence monitor (BIF) has been developed and successfully tested at the Institute of Applied Physics (IAP) of the Goethe University Frankfurt. This BIF is based on ten single-board cameras inserted into the vacuum and directed onto the beam axis. The overall goal is to study the beam with tomography algorithms at a low energy beam transport section. Recently, we tested the detector with a 60keV, 15mA proton beam at 20Hz and 1ms puls length. In this paper we present the ongoing investigations on image processing and application of the algebraic reconstruction technique (ART).
	Poster MOPORI01 [1.826 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI01
About •	Received ※ 20 August 2022 — Revised ※ 21 August 2022 — Accepted ※ 28 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, focusing, 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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPORI11	Seismic Analysis for Safety Requirements of SPIRAL2 Accelerator	experiment, simulation, linac, vacuum	252
	C. Barthe-Dejean, F. Lutton, M. Michel GANIL, Caen, France
	The SPIRAL2 Accelerator at GANIL is a superconducting ion continuous wave LINAC with two associated experimental areas. Mechanical engineers have been highly involved in the design of SPIRAL2 equipments since the beginning of the project in 2004. During the development phase, Computer Aided Design and calculation codes have been used throughout the complete process : from the ion sources, the LINAC, the beam transport lines and the experimental halls equipped with detectors. SPIRAL2 has to meet different safety requirements, among which seismic hazard. This involves justifying that the integrity of the radiologic containment barrier is always maintained in case of earthquake. This paper reports the improvement in design and calculation methods performed by GANIL engineers to meet the seismic safety requirements, specificly the non-missility feature of the equpiment. The modal-spectral simulations, used to demonstrate the mechanical strength of equipments in case of earthquakes, was an important part of this design activity in the past 10 years New methods have been used to calculate welds, fasteners and the ground anchor of the structural supports of the heaviest equipments. C. Barthe-Dejean, F. Lutton, « Guide methodologique pour Calculs de Tenue aux Séismes des équipements mécaniques », Note STP-535-A
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI11
About •	Received ※ 14 August 2022 — Revised ※ 19 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 02 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPORI18	Overview of STFC Daresbury Laboratory Vacuum Operations for the Testing of ESS High Beta Cavities.	cavity, vacuum, SRF, operation	268
	S. Wilde, K.J. Middleman, M.D. Pendleton, J.O.W. Poynton STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom D.A. Mason, G. Miller, J. Mutch STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom K.J. Middleman Cockcroft Institute, Warrington, Cheshire, United Kingdom
	This paper describes the vacuum systems and operations that are used at the STFC Daresbury Laboratory SuRF lab during cold RF testing of ESS high beta RF accelerating cavities. Dedicated slow pump slow vent (SPSV) systems are used to perform vacuum acceptance testing of each cavity before, during and after cold RF testing. Details of the vacuum systems, support facilities, acceptance criteria and test results will be discussed in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI18
About •	Received ※ 24 August 2022 — Revised ※ 01 September 2022 — Accepted ※ 02 September 2022 — Issue date ※ 09 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOJO13	Wire Scanner Systems at the European Spallation Source (ESS): Tests and First Beam Commissioning Results	MEBT, linac, MMI, controls	372
	C.S. Derrez, I. Bustinduy, E.M. Donegani, V. Grishin, H. Kocevar, J.P.S. Martins, N. Milas, R. Miyamoto, T.J. Shea, R. Tarkeshian, C.A. Thomas, P.L. van Velze ESS, Lund, Sweden S. Cleva, R. De Monte, M. Ferianis, S. Grulja Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy I. Mazkiaran, A.R. Páramo ESS Bilbao, Zamudio, Spain
	The ESS beam instrumentation includes 3 different type of Wire Scanners (WS). Double wires systems are deployed in the MEBT part of NCL, and single wires and flying wire instruments are being tested and installed in the higher energy sections of the ESS linac. First beam tests result from the MEBT systems will be presented. The superconducting linac WS systems are based on scintillator detectors and wavelength shifting fibers are mounted on the beam pipe. The detectors are coupled to long haul optical fibers, which carry the signals to custom front end electronics sitting in controls racks at the surface. The acquisition chain have been characterized at IHEP (Protvino, Russia), ELETTRA (Trieste, Italy), CERN PSB, CoSy (IKP, Germany) and SNS (USA) before installation in the ESS tunnel. The test results of this system design, differing from the standard approach where photomultipliers are coupled to the scintillator will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOJO13
About •	Received ※ 24 August 2022 — Revised ※ 29 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 01 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOPA06	Microscopy Investigation on Different Materials After Pulsed High Field Conditioning and Low Energy H-Irradiation	radiation, electron, experiment, cathode	422
	C.F. Da Palma Serafim, G. Bellodi, S. Calatroni, A. Grudiev, A.M. Lombardi, R.C. Peacock, A.T. Perez Fontenla, S. Ramberger, E. Sargsyan, S. Sgobba, W. Wuensch CERN, Meyrin, Switzerland F. Djurabekova HIP, University of Helsinki, Finland
	During operation the LINAC4 RFQ (Radio-Frequency-Quadrupole) is exposed to high electric fields which can lead to vacuum breakdown. It is also subject to beam loss that can cause surface modification, including blistering, which can result in reduced electric field handling and an increased breakdown rate. An experimental study has been made to identify materials with high electric field capability and robustness to low-energy irradiation. In this paper we briefly discuss the selection criteria and we analyze these materials investigating their metallurgical properties using advanced microscopic techniques such as Scanning Electron Microscope, Electron Back Scattered Diffraction, Energy-dispersive X-ray Spectroscopy and conventional optical microscopy. These allow to observe and characterize the different materials on aμand a nano-scale, allowing us to compare results before and after irradiation and breakdown testing.
	Poster TUPOPA06 [2.771 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA06
About •	Received ※ 14 August 2022 — Revised ※ 23 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 31 August 2022
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THPOPA04	Unfolding of Bremsstrahlung Photons Energy Spectra Emitted from Electron Cyclotron Resonance Ion Source	ECR, photon, plasma, electron	750
	M.J. Kumwenda University of Dar es Salaam, Dar es Salaam, Tanzania J.-K. Ahn Korea University, Seoul, Republic of Korea
	The aim of present study is to determine end-point energies of the bremsstrahlung photons energy spectra emitted from 28-GHz ECRIS by using inverse-matrix unfold method. Azimuthal angular distribution of the bremsstrahlung photons from 28-GHz ECRIS were measured at Busan Center of KBSI. Gamma-ray detection system consists of three round type NaI(Tl) scintillation detectors positioned 62 cm radially from the beam axis and another detector placed at the extraction port for monitoring photon intensity along the beam axis. Bremsstrahlung photons energy spectra were measured at six azimuthal angles at RF power of 1 kW. Monte Carlo simulation based on Geant4 package was performed to take the geometrical acceptance and energy-dependent detection efficiency into account due to large non-uniformity in the material budget. We extracted true bremsstrahlung energy spectra using the inverse-matrix unfolding method. The end-point energies of the bremsstrahlung photons after application of deconvolution method were found to be 1.320±0.050 MeV, 1.530±0.070 MeV, 1.540±0.070 MeV, 1.690±0.030 MeV, 1.530±0.070 MeV and 1.690±0.030 MeV for 0°, 30°, 60°, 90°, 120° and 330°, respectively.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOPA04
About •	Received ※ 23 August 2022 — Revised ※ 31 August 2022 — Accepted ※ 09 September 2022 — Issue date ※ 23 September 2022
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THPORI16	Machine Learning for RF Breakdown Detection at CLARA	cavity, network, gun, operation	858
	A.E. Pollard, D.J. Dunning, A.J. Gilfellon STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Maximising the accelerating gradient of RF structures is fundamental to improving accelerator facility performance and cost-effectiveness. Structures must be subjected to a conditioning process before operational use, in which the gradient is gradually increased up to the operating value. A limiting effect during this process is breakdown or vacuum arcing, which can cause damage that limits the ultimate operating gradient. Techniques to efficiently condition the cavities while minimising the number of breakdowns are therefore important. In this paper, machine learning techniques are applied to detect breakdown events in RF pulse traces by approaching the problem as anomaly detection, using a variational autoencoder. This process detects deviations from normal operation and classifies them with near perfect accuracy. Offline data from various sources has been used to develop the techniques, which we aim to test at the CLARA facility at Daresbury Laboratory. Deployment of the machine learning system on the high repetition rate gun upgrade at CLARA has begun.
	Poster THPORI16 [2.099 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPORI16
About •	Received ※ 22 August 2022 — Revised ※ 30 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 15 October 2022
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Paper

Title

Other Keywords

Page

MOPOJO11

Challenges for High-Energy X-Ray Security Screening Linacs

linac, electron, cavity, photon

50

M. Jenkins, J. Ollier, M.G. Procter
Rapiscan Systems Ltd, Stoke-on-Trent, United Kingdom

X-ray based Cargo and Vehicle Inspection (CVI) systems are used for security and customs inspections at a variety of locations. To provide the maximum flexibility many users require mobile CVI systems to allow vehicles to be screened efficiently for threats and contraband. The need for mobile systems means that the linear accelerator, and ancillary systems, used to generate the x-rays must be compact, rugged, and reliable. These systems must meet image performance tests specified by American National Standards Institute (ANSI) and the International Electrotechnical Commission (IEC). The IEC also defines a standard for material discrimination. The requirements of these standards mean that the x-ray output produced by the linac needs to be consistent during and between scans, with the stability and repeatability of the output being critical. The tolerances on the linac output to meet the performance standards combined with the need for a compact system gives an unusual challenge for the linac design. A review of how different stability measures impact the performance tests is presented. This is compared to current technologies and possible future linacs used for mobile CVI systems.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOJO11

About •

Received ※ 24 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 01 September 2022

Cite •

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

MOPOPA11

Laser-to-RF Synchronisation Drift Compensation for the CLARA test facility

laser, FEM, electron, timing

87

J. Henderson, A.J. Moss, E.W. Snedden
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
A.C. Dexter
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

Femtosecond synchronisation between charged particle beams and external laser systems is a significant challenge for modern particle accelerators. To achieve femtosecond synchronisation of the CLARA electron beam and end user laser systems will require tight synchronisation of several accelerator subsystems. This paper reports on a method to compensate for environmentally driven long-term drift in Laser-RF phase detection systems.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOPA11

About •

Received ※ 22 August 2022 — Revised ※ 26 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 15 September 2022

Cite •

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

MOPOGE25

Rf Measurement and Characterisation of European Spallation Source Cavities at UKRI-STFC Daresbury Laboratory and DESY

cavity, radiation, cryomodule, MMI

212

P.A. Smith, A.E.T. Akintola, K.D. Dumbell, M.J. Ellis, S. Hitchen, P.C. Hornickel, C.R. Jenkins, A.J. May, P.A. McIntosh, K.J. Middleman, A.J. Moss, S.M. Pattalwar, M.D. Pendleton, J.O.W. Poynton, A.E. Wheelhouse, S. Wilde
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
G. Jones, M. Lowe, D.A. Mason, G. Miller, J. Mutch, A. Oates, J.T.G. Wilson
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
K.J. Middleman
Cockcroft Institute, Warrington, Cheshire, United Kingdom
D. Reschke, L. Steder, M. Wiencek
DESY, Hamburg, Germany

The Accelerator Science and Technology Centre (ASTeC) is responsible for delivering 88 High Beta (HB) cavities as part of the European Spallation Source (ESS) facility in Sweden. The bulk Niobium Superconducting Radio Frequency (SRF) cavities operate at 704 MHz. They have been fabricated in industry and are currently being tested at Daresbury Laboratory and Deutsches Elektronen-Synchrotron (DESY). They will then be delivered to Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA) Saclay, France for integration into cryomodules. To date 50 cavities have been conditioned and evaluated and 36 cavities have been delivered to CEA. This paper discusses the experiences and testing of the cavities performed to date at both sites

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE25

About •

Received ※ 24 August 2022 — Revised ※ 29 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 04 September 2022

Cite •

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

MOPORI01

A Multi-Camera System for Tomographic Beam Diagnostics

vacuum, controls, synchrotron, diagnostics

215

A. Ateş, G. Blank, H. Hähnel, U. Ratzinger
IAP, Frankfurt am Main, Germany

A prototype of a beam-induced residual gas fluorescence monitor (BIF) has been developed and successfully tested at the Institute of Applied Physics (IAP) of the Goethe University Frankfurt. This BIF is based on ten single-board cameras inserted into the vacuum and directed onto the beam axis. The overall goal is to study the beam with tomography algorithms at a low energy beam transport section. Recently, we tested the detector with a 60keV, 15mA proton beam at 20Hz and 1ms puls length. In this paper we present the ongoing investigations on image processing and application of the algebraic reconstruction technique (ART).

Poster MOPORI01 [1.826 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI01

About •

Received ※ 20 August 2022 — Revised ※ 21 August 2022 — Accepted ※ 28 August 2022 — Issue date ※ 01 September 2022

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MOPORI08

Beam Mapping Linearity Improvement in Multi-Dimensional Bunch Shape Monitor

cavity, electron, focusing, 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

Cite •

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

MOPORI11

Seismic Analysis for Safety Requirements of SPIRAL2 Accelerator

experiment, simulation, linac, vacuum

252

C. Barthe-Dejean, F. Lutton, M. Michel
GANIL, Caen, France

The SPIRAL2 Accelerator at GANIL is a superconducting ion continuous wave LINAC with two associated experimental areas. Mechanical engineers have been highly involved in the design of SPIRAL2 equipments since the beginning of the project in 2004. During the development phase, Computer Aided Design and calculation codes have been used throughout the complete process : from the ion sources, the LINAC, the beam transport lines and the experimental halls equipped with detectors. SPIRAL2 has to meet different safety requirements, among which seismic hazard. This involves justifying that the integrity of the radiologic containment barrier is always maintained in case of earthquake. This paper reports the improvement in design and calculation methods performed by GANIL engineers to meet the seismic safety requirements, specificly the non-missility feature of the equpiment. The modal-spectral simulations, used to demonstrate the mechanical strength of equipments in case of earthquakes, was an important part of this design activity in the past 10 years New methods have been used to calculate welds, fasteners and the ground anchor of the structural supports of the heaviest equipments.
C. Barthe-Dejean, F. Lutton, « Guide methodologique pour Calculs de Tenue aux Séismes des équipements mécaniques », Note STP-535-A

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI11

About •

Received ※ 14 August 2022 — Revised ※ 19 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 02 September 2022

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

MOPORI18

Overview of STFC Daresbury Laboratory Vacuum Operations for the Testing of ESS High Beta Cavities.

cavity, vacuum, SRF, operation

268

S. Wilde, K.J. Middleman, M.D. Pendleton, J.O.W. Poynton
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
D.A. Mason, G. Miller, J. Mutch
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
K.J. Middleman
Cockcroft Institute, Warrington, Cheshire, United Kingdom

This paper describes the vacuum systems and operations that are used at the STFC Daresbury Laboratory SuRF lab during cold RF testing of ESS high beta RF accelerating cavities. Dedicated slow pump slow vent (SPSV) systems are used to perform vacuum acceptance testing of each cavity before, during and after cold RF testing. Details of the vacuum systems, support facilities, acceptance criteria and test results will be discussed in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPORI18

About •

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

Cite •

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

TUPOJO13

Wire Scanner Systems at the European Spallation Source (ESS): Tests and First Beam Commissioning Results

MEBT, linac, MMI, controls

372

C.S. Derrez, I. Bustinduy, E.M. Donegani, V. Grishin, H. Kocevar, J.P.S. Martins, N. Milas, R. Miyamoto, T.J. Shea, R. Tarkeshian, C.A. Thomas, P.L. van Velze
ESS, Lund, Sweden
S. Cleva, R. De Monte, M. Ferianis, S. Grulja
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
I. Mazkiaran, A.R. Páramo
ESS Bilbao, Zamudio, Spain

The ESS beam instrumentation includes 3 different type of Wire Scanners (WS). Double wires systems are deployed in the MEBT part of NCL, and single wires and flying wire instruments are being tested and installed in the higher energy sections of the ESS linac. First beam tests result from the MEBT systems will be presented. The superconducting linac WS systems are based on scintillator detectors and wavelength shifting fibers are mounted on the beam pipe. The detectors are coupled to long haul optical fibers, which carry the signals to custom front end electronics sitting in controls racks at the surface. The acquisition chain have been characterized at IHEP (Protvino, Russia), ELETTRA (Trieste, Italy), CERN PSB, CoSy (IKP, Germany) and SNS (USA) before installation in the ESS tunnel. The test results of this system design, differing from the standard approach where photomultipliers are coupled to the scintillator will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOJO13

About •

Received ※ 24 August 2022 — Revised ※ 29 August 2022 — Accepted ※ 30 August 2022 — Issue date ※ 01 September 2022

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

TUPOPA06

Microscopy Investigation on Different Materials After Pulsed High Field Conditioning and Low Energy H-Irradiation

radiation, electron, experiment, cathode

422

C.F. Da Palma Serafim, G. Bellodi, S. Calatroni, A. Grudiev, A.M. Lombardi, R.C. Peacock, A.T. Perez Fontenla, S. Ramberger, E. Sargsyan, S. Sgobba, W. Wuensch
CERN, Meyrin, Switzerland
F. Djurabekova
HIP, University of Helsinki, Finland

During operation the LINAC4 RFQ (Radio-Frequency-Quadrupole) is exposed to high electric fields which can lead to vacuum breakdown. It is also subject to beam loss that can cause surface modification, including blistering, which can result in reduced electric field handling and an increased breakdown rate. An experimental study has been made to identify materials with high electric field capability and robustness to low-energy irradiation. In this paper we briefly discuss the selection criteria and we analyze these materials investigating their metallurgical properties using advanced microscopic techniques such as Scanning Electron Microscope, Electron Back Scattered Diffraction, Energy-dispersive X-ray Spectroscopy and conventional optical microscopy. These allow to observe and characterize the different materials on aμand a nano-scale, allowing us to compare results before and after irradiation and breakdown testing.

Poster TUPOPA06 [2.771 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOPA06

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Received ※ 14 August 2022 — Revised ※ 23 August 2022 — Accepted ※ 29 August 2022 — Issue date ※ 31 August 2022

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THPOPA04

Unfolding of Bremsstrahlung Photons Energy Spectra Emitted from Electron Cyclotron Resonance Ion Source

ECR, photon, plasma, electron

750

M.J. Kumwenda
University of Dar es Salaam, Dar es Salaam, Tanzania
J.-K. Ahn
Korea University, Seoul, Republic of Korea

The aim of present study is to determine end-point energies of the bremsstrahlung photons energy spectra emitted from 28-GHz ECRIS by using inverse-matrix unfold method. Azimuthal angular distribution of the bremsstrahlung photons from 28-GHz ECRIS were measured at Busan Center of KBSI. Gamma-ray detection system consists of three round type NaI(Tl) scintillation detectors positioned 62 cm radially from the beam axis and another detector placed at the extraction port for monitoring photon intensity along the beam axis. Bremsstrahlung photons energy spectra were measured at six azimuthal angles at RF power of 1 kW. Monte Carlo simulation based on Geant4 package was performed to take the geometrical acceptance and energy-dependent detection efficiency into account due to large non-uniformity in the material budget. We extracted true bremsstrahlung energy spectra using the inverse-matrix unfolding method. The end-point energies of the bremsstrahlung photons after application of deconvolution method were found to be 1.320±0.050 MeV, 1.530±0.070 MeV, 1.540±0.070 MeV, 1.690±0.030 MeV, 1.530±0.070 MeV and 1.690±0.030 MeV for 0°, 30°, 60°, 90°, 120° and 330°, respectively.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOPA04

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Received ※ 23 August 2022 — Revised ※ 31 August 2022 — Accepted ※ 09 September 2022 — Issue date ※ 23 September 2022

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THPORI16

Machine Learning for RF Breakdown Detection at CLARA

cavity, network, gun, operation

858

A.E. Pollard, D.J. Dunning, A.J. Gilfellon
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Maximising the accelerating gradient of RF structures is fundamental to improving accelerator facility performance and cost-effectiveness. Structures must be subjected to a conditioning process before operational use, in which the gradient is gradually increased up to the operating value. A limiting effect during this process is breakdown or vacuum arcing, which can cause damage that limits the ultimate operating gradient. Techniques to efficiently condition the cavities while minimising the number of breakdowns are therefore important. In this paper, machine learning techniques are applied to detect breakdown events in RF pulse traces by approaching the problem as anomaly detection, using a variational autoencoder. This process detects deviations from normal operation and classifies them with near perfect accuracy. Offline data from various sources has been used to develop the techniques, which we aim to test at the CLARA facility at Daresbury Laboratory. Deployment of the machine learning system on the high repetition rate gun upgrade at CLARA has begun.

Poster THPORI16 [2.099 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPORI16

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Received ※ 22 August 2022 — Revised ※ 30 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 15 October 2022

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