IPAC2021 - List of Keywords (background)

Paper	Title	Other Keywords	Page
MOPAB276	Investigation on the injection of the Arronax Cyclotron 70XP	cyclotron, injection, solenoid, radiation	873
	F. Poirier, F. Bulteau-Harel, T. Durand, X. Goiziou, C. Koumeir, C. Lassalle, H. Trichet Cyclotron ARRONAX, Saint-Herblain, France F. Haddad SUBATECH, Nantes, France
	Funding: This work is supported by grants from the ANR program "Investissements d’Avenir", n°ANR-11-EQPX-0004, n°ANR-11-LABX-18-01 and n°ANR-16-IDE-0007 and by a PhD scholarship from CNRS/IN2P3. A 70 MeV cyclotron is being used at the Arronax GIP (Interest Public Group), France, for various types of R&D on nuclear, biological and chemical reactions with beams and radioisotopes production. In order to adapt its usage for experiments and users demands of high peak intensity, above an equivalent average of a few µA, the injection is being adapted. Several studies are thus being performed in this section. These include the newly installed chopper-based system and the injection collimator. This paper details the various studies, specifically the signal purity obtained in the pulsed mode. A mode particularly adapted for flash irradiation.
	Poster MOPAB276 [2.522 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB276
About •	paper received ※ 19 May 2021 paper accepted ※ 23 June 2021 issue date ※ 15 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB279	Non-Invasive Beam Profile Monitoring for the HL-LHC Hollow Electron Lens	photon, electron, proton, luminosity	884
	A. Salehilashkajani, N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang The University of Liverpool, Liverpool, United Kingdom M. Ady, N.S. Chritin, N. Jens, O.R. Jones, R. Kersevan, T. Lefèvre, S. Mazzoni, G. Papazoglou, A. Rossi, G. Schneider, R. Veness CERN, Geneva, Switzerland P. Forck, S. Udrea GSI, Darmstadt, Germany N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1 and the STFC Cockcroft core grant No. ST/G008248/1. A Hollow Electron Lens (HEL) is currently under development for the High-Luminosity upgrade of the Large Hadron Collider (HL-LHC). In this device, a hollow electron beam co-propagates with a central proton beam and provides active halo control in the LHC. To ensure the concentricity of the two beams, a non-invasive diagnostic instrument is currently being commissioned. This instrument is a compact version of an existing prototype that leverages beam induced fluorescence with supersonic gas curtain technology. This contribution includes the design features of this version of the monitor, recent progress, and future plans for tests at the Cockcroft Institute and the electron lens test stand at CERN.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB279
About •	paper received ※ 18 May 2021 paper accepted ※ 15 June 2021 issue date ※ 02 September 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB131	Measurement of Coherent Smith-Purcell Radiation Using Ultra-Short Electron Bunch at T-Acts	radiation, electron, experiment, bunching	1696
	H. Yamada, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, K. Shibata, K. Takahashi Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
	The coherent Smith-Purcell radiation (SPR) emitted as a short electron bunch passes over a periodic metal surface is expected to be applied as a non-destructive beam diagnostic tool. The longitudinal profile of the electron bunch can be deduced by the measured spectrum of the coherent SPR, which is compared with the theoretical one for single electron. There are several theoretical models that explain the SPR mechanism, such as the surface current (SC) model and the van den Berg model. But the difference of estimation in radiation intensity between different models is not trivial, and also the experimental data to evaluate those validity is not enough. At test accelerator, t-ACTS, in Tohoku University we are conducting experimental research on coherent SPR in the terahertz frequency region using an ultra-short electron bunch of about 100 fs. The status and results of the experiment will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB131
About •	paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 13 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB248	A Parallel Time Domain Thermal Solver for Transient Analysis of Accelerator Cavities	cavity, gun, simulation, software	2030
	C.-K. Ng, L. Ge, Z. Li, L. Xiao SLAC, Menlo Park, California, USA
	Funding: Work supported by US DOE under contract AC02-76SF00515. Simulation of thermal effects in accelerator cavity is normally performed assuming steady state solution where a static thermal solver suffices to evaluate temperature gradients and impacts on mechanical design. However, during the rf pulse ramp up or the machine system cool-down process, when the field in the cavity changes rapidly, transient effects need to be taken into account. A parallel time domain thermal solver has been developed in the finite element multi-physics code suite ACE3P with integrated electromagnetic, thermal and mechanical modeling capabilities. The implementation takes advantage of the parallel computation infrastructure of ACE3P and shares most of the ingredients in mesh generation, matrix assembly, time advancement scheme and postprocessing. In this paper, we will outline the finite element formulation of the transient thermal problem and verify the implementation against analytical solutions and existing numerical results. The thermal solver has also been coupled to ACE3P mechanical solver, allowing stress and strain analysis during the transient stage. Application of the transient thermal solver to realistic accelerator cavities will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB248
About •	paper received ※ 19 May 2021 paper accepted ※ 25 August 2021 issue date ※ 02 September 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB281	Gas-Mixing to Improve the Resolution of Non-Invasive Gas Jet-Based Ionization Profile Monitors	injection, electron, simulation, vacuum	2132
	N. Kumar, A. Salehilashkajani, C.P. Welsch, H.D. Zhang Cockcroft Institute, Warrington, Cheshire, United Kingdom N. Kumar, A. Salehilashkajani, C.P. Welsch, H.D. Zhang The University of Liverpool, Liverpool, United Kingdom
	Funding: This work is supported by the HL-LHC-UK project funded by STFC and CERN and the STFC Cockcroft core grant No. ST/G008248/1. Ionization beam profile monitor using a supersonic gas jet is an attractive option for the characterization of low and medium energy beams. In this scheme, a primary beam crosses a 45-degree tilted thin gas curtain which causes ionization of gas molecules in the jet. The generated ions are then collected using an electrostatic extraction system to determine the 2D transverse profile of the primary beam. The most commonly used gases for the jet are neon and nitrogen. The signal from the gas jet is always super-imposed with the signal resulting from residual gases in the interaction chamber. CST simulations indicate that the gas jet speed is a key factor for the separation of the jet and the residual gas signals. To obtain a good signal separation, one can increase the velocity of the gas jet. This can be accomplished by generating a gas jet that mixes heavier and lighter gases. This contribution gives a general overview of the monitor design, discusses the effects of gas mixing and CST simulation results. It also presents experimental results obtained with Helium, and Nitrogen, as well as a mixture of them using different percentages and the impact on measurement resolution.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB281
About •	paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 13 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB406	Search for New Isotope Production Pathways	target, neutron, isotope-production, diagnostics	2475
	L.F. Dabill Coe College, Cedar Rapids, Iowa, USA A. Hutton JLab, Newport News, Virginia, USA
	The isotope group at Jefferson Lab is carrying out R&D for producing medically interesting radioisotopes, especially those with theranostic (therapeutic and diagnostic) attributes. Here the search for viable production mechanisms has been expanded to multi-step reactions where a daughter is produced from the target and decays into a medically interesting granddaughter radioisotope. It is difficult to find efficient production routes when investigating both the initial excitation reaction as well as the decay routes leading to medically interesting isotopes. The overall goal of this project is to create a structured code in Python to find these decay routes by automatically exploring the large number of isotopes and their possible decay modes. The program structure is described, and preliminary results are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB406
About •	paper received ※ 19 May 2021 paper accepted ※ 31 May 2021 issue date ※ 14 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB410	Finite Element Analysis and Experimental Validation of Low-Pressure Beam Windows for XCET Detectors at CERN	experiment, Windows, detector, photon	2487
	J. Buesa Orgaz, M. Brugger, G. Romagnoli, O. Sacristan De Frutos, F. Sanchez Galan CERN, Meyrin, Switzerland
	In the framework of the renovation and consolidation of experimental areas at CERN, a low-pressure design beam superimposed windows (250 µm Mylar and 150 µm polyethylene) for the Threshold Cherenkov counters (XCET) has been modelled and verified for its implementation. The XCET is a detector used to count the number of selected charged particles in the beam by adjusting the pressure that leads to the emission of Cherenkov photons only above certain pressure threshold. Simultaneously, the charged particles pass from a vacuum environment to the pressurized refractive gas vessel through a solid interface. Minimal material in this solid interface is therefore crucial to avoid interactions of the low-energy particles which may lead to beam intensity loss or background production. Hence, thin and low-density materials are required to mitigate multiple scattering and energy loss of the incoming particles while still allowing the needed pressures inside the counter vessel. A XCET validation methodology was conducted using Finite Element Analysis (FEA), followed by experimental validations performing burst pressure tests and using Digital Image Correlation (DIC).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB410
About •	paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 24 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXA07	Beam Background Measurements at SuperKEKB/Belle-II in 2020	luminosity, injection, detector, scattering	2532
	H.N. Nakayama, T. Koga KEK, Ibaraki, Japan K. Kojima Nagoya University, Nagoya, Japan A. Natochii, S. Vahsen University of Hawaii, Honolulu,, USA
	The SuperKEKB electron-positron collider began collision operation in 2018 and achieved the world-record luminosity of 2.4x10³⁴~cm^-2s^-1 in June 2020. We pursue higher luminosity by squeezing beam sizes and increasing beam currents. Beam backgrounds induced by stray particles will also increase and might cause severe radiation damage to Belle II detector components and worsen the quality of collected physics data. To mitigate these backgrounds, we have carefully designed our interaction region and installed movable collimators in the machine. We present recent measurements of beam background at SuperKEKB. We have performed dedicated machine studies to measure each background component separately and found that beam-gas scattering and Touschek scattering in the positron ring are the dominant sources of background rates in Belle II. We also present the latest observations of injection background, which determines the timing of a required Belle II data acquisition trigger veto and therefore affects the integrated luminosity. We show the beam background extrapolation toward the expected higher-luminosity operation and our plans for further background mitigation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXA07
About •	paper received ※ 20 May 2021 paper accepted ※ 25 June 2021 issue date ※ 13 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB029	Challenges for the Interaction Region Design of the Future Circular Collider FCC-ee	photon, detector, simulation, collider	2668
	M. Boscolo, A. Ciarma, F. Fransesini, L. Pellegrino INFN/LNF, Frascati, Italy N. Bacchetta INFN- Sez. di Padova, Padova, Italy M. Benedikt, H. Burkhardt, M.A. Jones, R. Kersevan, M. Lueckhof, E. Montbarbon, K. Oide, L. Watrelot, F. Zimmermann CERN, Meyrin, Switzerland L. Brunetti, M. Serluca IN2P3-LAPP, Annecy-le-Vieux, France M. Dam NBI, København, Denmark M. Koratzinos MIT, Cambridge, Massachusetts, USA M. Migliorati INFN-Roma1, Rome, Italy A. Novokhatski, M.K. Sullivan SLAC, Menlo Park, California, USA F. Poirier CNRS - DR17, RENNES, France
	Funding: This work was partially supported by the EC HORIZON 2020 project FCC-IS, grant agreement n.951754, and by the U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-76SF-00515. The FCC-ee is a proposed future high-energy, high-intensity and high precision lepton collider. Here, we present the latest developments for the FCC-ee interaction regions, which shall ensure optimum conditions for the particle physics experiments. We discuss measures of background reduction and a revised interaction region layout including a low impedance compact beam chamber design. We also discuss the possible impact of the radiation generated in the interaction region including beamstrahlung.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB029
About •	paper received ※ 11 May 2021 paper accepted ※ 23 June 2021 issue date ※ 30 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB003	Application of Generalized Gaussian Distribution in the Processing the Wire Scanner Data	emittance, hadron, linac, electron	3759
	H. Geng, C. Meng, F. Yan, Y. Zhang, Y.L. Zhao IHEP, Beijing, People’s Republic of China
	Wire scanners are widely used for measuring beam emittance in both electron and hadron accelerators. Gaussian fitting is the most commonly used method in processing the wire scanner data. But in hadron machines, beams are normally not gaussian distribution due to the action of nonlinear forces such as space charge effect. Under these circumstances, there would be big deviations if the wire scanner data was still fitted with gaussian distributions. This paper introduces generalized Gaussian distribution in the processing the wire scanner data measured in the ADS injector-I. The results using different fitting method will be compared.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB003
About •	paper received ※ 14 May 2021 paper accepted ※ 18 June 2021 issue date ※ 30 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPAB276

Investigation on the injection of the Arronax Cyclotron 70XP

cyclotron, injection, solenoid, radiation

873

F. Poirier, F. Bulteau-Harel, T. Durand, X. Goiziou, C. Koumeir, C. Lassalle, H. Trichet
Cyclotron ARRONAX, Saint-Herblain, France
F. Haddad
SUBATECH, Nantes, France

Funding: This work is supported by grants from the ANR program "Investissements d’Avenir", n°ANR-11-EQPX-0004, n°ANR-11-LABX-18-01 and n°ANR-16-IDE-0007 and by a PhD scholarship from CNRS/IN2P3.
A 70 MeV cyclotron is being used at the Arronax GIP (Interest Public Group), France, for various types of R&D on nuclear, biological and chemical reactions with beams and radioisotopes production. In order to adapt its usage for experiments and users demands of high peak intensity, above an equivalent average of a few µA, the injection is being adapted. Several studies are thus being performed in this section. These include the newly installed chopper-based system and the injection collimator. This paper details the various studies, specifically the signal purity obtained in the pulsed mode. A mode particularly adapted for flash irradiation.

Poster MOPAB276 [2.522 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB276

About •

paper received ※ 19 May 2021 paper accepted ※ 23 June 2021 issue date ※ 15 August 2021

Export •

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

MOPAB279

Non-Invasive Beam Profile Monitoring for the HL-LHC Hollow Electron Lens

photon, electron, proton, luminosity

884

A. Salehilashkajani, N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom
M. Ady, N.S. Chritin, N. Jens, O.R. Jones, R. Kersevan, T. Lefèvre, S. Mazzoni, G. Papazoglou, A. Rossi, G. Schneider, R. Veness
CERN, Geneva, Switzerland
P. Forck, S. Udrea
GSI, Darmstadt, Germany
N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This work was supported by the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1 and the STFC Cockcroft core grant No. ST/G008248/1.
A Hollow Electron Lens (HEL) is currently under development for the High-Luminosity upgrade of the Large Hadron Collider (HL-LHC). In this device, a hollow electron beam co-propagates with a central proton beam and provides active halo control in the LHC. To ensure the concentricity of the two beams, a non-invasive diagnostic instrument is currently being commissioned. This instrument is a compact version of an existing prototype that leverages beam induced fluorescence with supersonic gas curtain technology. This contribution includes the design features of this version of the monitor, recent progress, and future plans for tests at the Cockcroft Institute and the electron lens test stand at CERN.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB279

About •

paper received ※ 18 May 2021 paper accepted ※ 15 June 2021 issue date ※ 02 September 2021

Export •

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

TUPAB131

Measurement of Coherent Smith-Purcell Radiation Using Ultra-Short Electron Bunch at T-Acts

radiation, electron, experiment, bunching

1696

H. Yamada, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, K. Shibata, K. Takahashi
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan

The coherent Smith-Purcell radiation (SPR) emitted as a short electron bunch passes over a periodic metal surface is expected to be applied as a non-destructive beam diagnostic tool. The longitudinal profile of the electron bunch can be deduced by the measured spectrum of the coherent SPR, which is compared with the theoretical one for single electron. There are several theoretical models that explain the SPR mechanism, such as the surface current (SC) model and the van den Berg model. But the difference of estimation in radiation intensity between different models is not trivial, and also the experimental data to evaluate those validity is not enough. At test accelerator, t-ACTS, in Tohoku University we are conducting experimental research on coherent SPR in the terahertz frequency region using an ultra-short electron bunch of about 100 fs. The status and results of the experiment will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB131

About •

paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 13 August 2021

Export •

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

TUPAB248

A Parallel Time Domain Thermal Solver for Transient Analysis of Accelerator Cavities

cavity, gun, simulation, software

2030

C.-K. Ng, L. Ge, Z. Li, L. Xiao
SLAC, Menlo Park, California, USA

Funding: Work supported by US DOE under contract AC02-76SF00515.
Simulation of thermal effects in accelerator cavity is normally performed assuming steady state solution where a static thermal solver suffices to evaluate temperature gradients and impacts on mechanical design. However, during the rf pulse ramp up or the machine system cool-down process, when the field in the cavity changes rapidly, transient effects need to be taken into account. A parallel time domain thermal solver has been developed in the finite element multi-physics code suite ACE3P with integrated electromagnetic, thermal and mechanical modeling capabilities. The implementation takes advantage of the parallel computation infrastructure of ACE3P and shares most of the ingredients in mesh generation, matrix assembly, time advancement scheme and postprocessing. In this paper, we will outline the finite element formulation of the transient thermal problem and verify the implementation against analytical solutions and existing numerical results. The thermal solver has also been coupled to ACE3P mechanical solver, allowing stress and strain analysis during the transient stage. Application of the transient thermal solver to realistic accelerator cavities will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB248

About •

paper received ※ 19 May 2021 paper accepted ※ 25 August 2021 issue date ※ 02 September 2021

Export •

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

TUPAB281

Gas-Mixing to Improve the Resolution of Non-Invasive Gas Jet-Based Ionization Profile Monitors

injection, electron, simulation, vacuum

2132

N. Kumar, A. Salehilashkajani, C.P. Welsch, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom
N. Kumar, A. Salehilashkajani, C.P. Welsch, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom

Funding: This work is supported by the HL-LHC-UK project funded by STFC and CERN and the STFC Cockcroft core grant No. ST/G008248/1.
Ionization beam profile monitor using a supersonic gas jet is an attractive option for the characterization of low and medium energy beams. In this scheme, a primary beam crosses a 45-degree tilted thin gas curtain which causes ionization of gas molecules in the jet. The generated ions are then collected using an electrostatic extraction system to determine the 2D transverse profile of the primary beam. The most commonly used gases for the jet are neon and nitrogen. The signal from the gas jet is always super-imposed with the signal resulting from residual gases in the interaction chamber. CST simulations indicate that the gas jet speed is a key factor for the separation of the jet and the residual gas signals. To obtain a good signal separation, one can increase the velocity of the gas jet. This can be accomplished by generating a gas jet that mixes heavier and lighter gases. This contribution gives a general overview of the monitor design, discusses the effects of gas mixing and CST simulation results. It also presents experimental results obtained with Helium, and Nitrogen, as well as a mixture of them using different percentages and the impact on measurement resolution.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB281

About •

paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 13 August 2021

Export •

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

TUPAB406

Search for New Isotope Production Pathways

target, neutron, isotope-production, diagnostics

2475

L.F. Dabill
Coe College, Cedar Rapids, Iowa, USA
A. Hutton
JLab, Newport News, Virginia, USA

The isotope group at Jefferson Lab is carrying out R&D for producing medically interesting radioisotopes, especially those with theranostic (therapeutic and diagnostic) attributes. Here the search for viable production mechanisms has been expanded to multi-step reactions where a daughter is produced from the target and decays into a medically interesting granddaughter radioisotope. It is difficult to find efficient production routes when investigating both the initial excitation reaction as well as the decay routes leading to medically interesting isotopes. The overall goal of this project is to create a structured code in Python to find these decay routes by automatically exploring the large number of isotopes and their possible decay modes. The program structure is described, and preliminary results are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB406

About •

paper received ※ 19 May 2021 paper accepted ※ 31 May 2021 issue date ※ 14 August 2021

Export •

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

TUPAB410

Finite Element Analysis and Experimental Validation of Low-Pressure Beam Windows for XCET Detectors at CERN

experiment, Windows, detector, photon

2487

J. Buesa Orgaz, M. Brugger, G. Romagnoli, O. Sacristan De Frutos, F. Sanchez Galan
CERN, Meyrin, Switzerland

In the framework of the renovation and consolidation of experimental areas at CERN, a low-pressure design beam superimposed windows (250 µm Mylar and 150 µm polyethylene) for the Threshold Cherenkov counters (XCET) has been modelled and verified for its implementation. The XCET is a detector used to count the number of selected charged particles in the beam by adjusting the pressure that leads to the emission of Cherenkov photons only above certain pressure threshold. Simultaneously, the charged particles pass from a vacuum environment to the pressurized refractive gas vessel through a solid interface. Minimal material in this solid interface is therefore crucial to avoid interactions of the low-energy particles which may lead to beam intensity loss or background production. Hence, thin and low-density materials are required to mitigate multiple scattering and energy loss of the incoming particles while still allowing the needed pressures inside the counter vessel. A XCET validation methodology was conducted using Finite Element Analysis (FEA), followed by experimental validations performing burst pressure tests and using Digital Image Correlation (DIC).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB410

About •

paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 24 August 2021

Export •

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

WEXA07

Beam Background Measurements at SuperKEKB/Belle-II in 2020

luminosity, injection, detector, scattering

2532

H.N. Nakayama, T. Koga
KEK, Ibaraki, Japan
K. Kojima
Nagoya University, Nagoya, Japan
A. Natochii, S. Vahsen
University of Hawaii, Honolulu,, USA

The SuperKEKB electron-positron collider began collision operation in 2018 and achieved the world-record luminosity of 2.4x10³⁴~cm^-2s^-1 in June 2020. We pursue higher luminosity by squeezing beam sizes and increasing beam currents. Beam backgrounds induced by stray particles will also increase and might cause severe radiation damage to Belle II detector components and worsen the quality of collected physics data. To mitigate these backgrounds, we have carefully designed our interaction region and installed movable collimators in the machine. We present recent measurements of beam background at SuperKEKB. We have performed dedicated machine studies to measure each background component separately and found that beam-gas scattering and Touschek scattering in the positron ring are the dominant sources of background rates in Belle II. We also present the latest observations of injection background, which determines the timing of a required Belle II data acquisition trigger veto and therefore affects the integrated luminosity. We show the beam background extrapolation toward the expected higher-luminosity operation and our plans for further background mitigation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXA07

About •

paper received ※ 20 May 2021 paper accepted ※ 25 June 2021 issue date ※ 13 August 2021

Export •

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

WEPAB029

Challenges for the Interaction Region Design of the Future Circular Collider FCC-ee

photon, detector, simulation, collider

2668

M. Boscolo, A. Ciarma, F. Fransesini, L. Pellegrino
INFN/LNF, Frascati, Italy
N. Bacchetta
INFN- Sez. di Padova, Padova, Italy
M. Benedikt, H. Burkhardt, M.A. Jones, R. Kersevan, M. Lueckhof, E. Montbarbon, K. Oide, L. Watrelot, F. Zimmermann
CERN, Meyrin, Switzerland
L. Brunetti, M. Serluca
IN2P3-LAPP, Annecy-le-Vieux, France
M. Dam
NBI, København, Denmark
M. Koratzinos
MIT, Cambridge, Massachusetts, USA
M. Migliorati
INFN-Roma1, Rome, Italy
A. Novokhatski, M.K. Sullivan
SLAC, Menlo Park, California, USA
F. Poirier
CNRS - DR17, RENNES, France

Funding: This work was partially supported by the EC HORIZON 2020 project FCC-IS, grant agreement n.951754, and by the U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-76SF-00515.
The FCC-ee is a proposed future high-energy, high-intensity and high precision lepton collider. Here, we present the latest developments for the FCC-ee interaction regions, which shall ensure optimum conditions for the particle physics experiments. We discuss measures of background reduction and a revised interaction region layout including a low impedance compact beam chamber design. We also discuss the possible impact of the radiation generated in the interaction region including beamstrahlung.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB029

About •

paper received ※ 11 May 2021 paper accepted ※ 23 June 2021 issue date ※ 30 August 2021

Export •

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

THPAB003

Application of Generalized Gaussian Distribution in the Processing the Wire Scanner Data

emittance, hadron, linac, electron

3759

H. Geng, C. Meng, F. Yan, Y. Zhang, Y.L. Zhao
IHEP, Beijing, People’s Republic of China

Wire scanners are widely used for measuring beam emittance in both electron and hadron accelerators. Gaussian fitting is the most commonly used method in processing the wire scanner data. But in hadron machines, beams are normally not gaussian distribution due to the action of nonlinear forces such as space charge effect. Under these circumstances, there would be big deviations if the wire scanner data was still fitted with gaussian distributions. This paper introduces generalized Gaussian distribution in the processing the wire scanner data measured in the ADS injector-I. The results using different fitting method will be compared.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB003

About •

paper received ※ 14 May 2021 paper accepted ※ 18 June 2021 issue date ※ 30 August 2021

Export •

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