Keyword: shielding
Paper Title Other Keywords Page
MOPOMS041 Concrete Shielding Activation for Proton Therapy Systems Using BDSIM and FISPACT-II proton, neutron, septum, simulation 728
 
  • E. Ramoisiaux, E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse, M. Vanwelde
    ULB, Bruxelles, Belgium
  • C. Hernalsteens
    CERN, Meyrin, Switzerland
  • F. Stichelbaut
    IBA, Louvain-la-Neuve, Belgium
 
  Proton therapy systems are used worldwide for patient treatment and fundamental research. The generation of secondary particles when the beam interacts with the beamline elements is a well-known issue. In particular, the energy degrader is the dominant source of secondary radiation. This poses new challenges for the concrete shielding of compact systems and beamline elements activation computation. We use a novel methodology to seamlessly simulate all the processes relevant to the activation evaluation. A realistic model of the system is developed using Beam Delivery Simulation (BDSIM), a Geant4-based particle tracking code that allows a single model to simulate primary and secondary particle tracking and all particle-matter interactions. The secondary particle fluxes extracted from the simulations are provided as input to FISPACT-II to compute the activation by solving the rate equations. This approach is applied to the Ion Beam Applications (IBA) Proteus®ONE (P1) system and the shielding of the proton therapy research centre of Charleroi, Belgium. Proton loss distributions are used to model the production of secondary neutrals inside the accelerator structure. Two models for the distribution of proton losses are compared for the computation of the clearance index at specific locations of the design. Results show that the variation in the accelerator loss models can be characterised as a systematic error.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS041  
About • Received ※ 19 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 22 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOMS044 Implications and Mitigation of Radiation Effects on the CERN SPS Operation during 2021 radiation, electronics, electron, operation 740
 
  • Y.Q. Aguiar, A. Apollonio, K. Biłko, M. Brucoli, M. Cecchetto, S. Danzeca, R. García Alía, T. Ladzinski, G. Lerner, J.B. Potoine, A. Zimmaro
    CERN, Meyrin, Switzerland
 
  During the Long Shutdown 2 (LS2, 2019-2020), the CERN accelerator complex has undergone major upgrades, mainly in preparation for the High-Luminosity (HL) LHC era, the ultimate capacity for its physics production. Therefore, several novel equipment and systems were designed and deployed throughout the accelerator complex. To comply with the radiation level specifications and avoid machine downtime due to radiation effects, the electronics systems exposed to radiation need to follow Radiation Hardness Assurance (RHA) methodologies developed and validated by the Radiation to Electronics (R2E) project at CERN. However, the establishment of such procedures is not yet fully implemented in the LHC injector chain, and some R2E failures were detected in the SPS during the 2021 operation. This work is devoted to describing and analysing the R2E failures and their impact on operation, in the context of the related radiation levels and equipment sensitivity.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS044  
About • Received ※ 07 June 2022 — Revised ※ 21 June 2022 — Accepted ※ 26 June 2022 — Issue date ※ 08 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOTK027 Field Emission Measurements at Lund Test Stand detector, cavity, cryomodule, SRF 1265
 
  • C.G. Maiano, N. Elias, E. Laface, P. Pierini, L. Sagliano, M.Y. Wang
    ESS, Lund, Sweden
  • E. Cenni
    CEA-IRFU, Gif-sur-Yvette, France
 
  We present here a description of field emission (FE) measurements set-up developed for elliptical cryomodules test activities at Lund Test Stand 2. A test campaign of field emission measurements has been developed and optimized during cryomodules tests. The scintillator detectors (and their respective shields), chosen for these measurements, have been characterized and optimized. The field emission application has been developed and integrated in the cryomodules tests operator interface. The Initial test results are presented and commented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK027  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 10 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOST001 Radiation Load Studies for Superconducting Dipole Magnets in a 10 TeV Muon Collider collider, radiation, dipole, electron 1671
 
  • D. Calzolari, C. Carli, B. Humann, A. Lechner, G. Lerner, F. Salvat Pujol, D. Schulte, K. Skoufaris
    CERN, Meyrin, Switzerland
  • B. Humann
    TU Vienna, Wien, Austria
 
  Among the various future lepton colliders under study, muon colliders offer the prospect of reaching the highest collision energies. Despite the promising potential of a multi-TeV muon collider, the short lifetime of muons poses a severe technological challenge for the collider design. In particular, the copious production of decay electrons and positrons along the collider ring requires the integration of continuous radiation absorbers inside superconducting magnets. The absorbers are needed to avoid quenches, reduce the heat dissipation in the cold mass and prevent magnet failures due to long-term radiation damage. In this paper, we present FLUKA shower simulations assessing the shielding requirements for high-field magnets of a 10 TeV muon collider. We quantify in particular the role of synchrotron photon emission by decay electrons and positrons, which helps in dispersing the energy carried by the decay products. For comparison, selected results for a 3 TeV muon collider are also presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST001  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 16 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOST002 Synchrotron Radiation Impact on the FCC-ee Arcs radiation, electron, neutron, electronics 1675
 
  • B. Humann
    TU Vienna, Wien, Austria
  • F. Cerutti, B. Humann, R. Kersevan
    CERN, Meyrin, Switzerland
 
  Synchrotron radiation (SR) emitted by electron and positrons beams represents a major loss source in high energy circular colliders, such as the lepton version of the Future Circular Collider (FCC-ee) at CERN. In particular, for the operation mode at 182.5 GeV (above the top pair threshold), its spectrum makes it penetrate well beyond the vacuum chamber walls. In order to optimize its containment, dedicated absorbers are envisaged. In this contribution we report the energy deposition studies performed with FLUKA to assess heat load, time-integrated dose, power density and particle fluence distribution in the machine components and the surrounding environment. Different choices for the absorber material were considered and shielding options for electronics were investigated. Furthermore, possible positions for the booster ring were reviewed from the radiation exposure point of view.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST002  
About • Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 03 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOPT016 Beam-Based Reconstruction of the Shielded Quench-Heater Fields for the LHC Main Dipoles dipole, operation, optics, injection 1874
 
  • L.C. Richtmann, L. Bortot, E. Ravaioli, C. Wiesner, D. Wollmann
    CERN, Meyrin, Switzerland
 
  Small orbit oscillations of the circulating particle beams have been observed immediately following quenches in the LHC’s superconducting main dipole magnets. Magnetic fields generated during the discharge into the quench heaters were identified as the cause. Since the resulting, shielded field inside the beam screen cannot be measured in-situ, the time evolution of the field has to be reconstructed from the measured beam excursions. In this paper, the field-reconstruction method using rotation in normalized phase space and the optimized fitting algorithm are described. The resulting rise times and magnetic field levels are presented for quench events that occurred during regular operation as well as for dedicated beam experiments. Finally, different approaches to model the shielding behavior of the beam screen are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT016  
About • Received ※ 16 May 2022 — Accepted ※ 13 June 2022 — Issue date ※ 26 June 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOST026 Design of the Magnetic Shield for VSR DEMO cavity, simulation, SRF, GUI 2501
 
  • H.-W. Glock, P. Anumula, F. Glöckner, J. Knobloch, F. Pflocksch, A. Vélez
    HZB, Berlin, Germany
  • J. Knobloch
    University of Siegen, Siegen, Germany
  • A. Vélez
    Technical University Dortmund, Dortmund, Germany
 
  Funding: Work supported by grants of the Helmholtz Association
The VSR DEMO module, recently under development at HZB, will house two 4-cell 1.5 GHz superconducting RF cavities with a particularly powerful HOM damping scheme based on five waveguide HOM absorbers per cavity. A magnetic shield made of high-permeable material is needed around the cavities in order to prevent the ambient magnetic field exceeding very few µT thereby causing considerable unwanted RF losses. The shield needs to accommodate the waveguides, the fundamental power coupler, two beam pipes, two He feed / return lines, the tuner and the support structures, whilst being manufacturable and mountable. The paper discusses those difficulties and presents the matured magnetic shield design. Numerical simulations are used to evaluate the efficacy of the shield.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST026  
About • Received ※ 14 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 22 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOST037 Analysis with MECAmaster on the Chain of Design Tolerances for the Target Systems at the European Spallation Source - ESS alignment, target, neutron, interface 2524
 
  • A. Bignami, N. Gazis, S. Ghatnekar Nilsson
    ESS, Lund, Sweden
  • B. Nicquevert
    CERN, Meyrin, Switzerland
 
  The European Spallation Source - ESS, has achieved its major construction in Lund, Sweden and is currently continuing in parallel to commissioning its first systems. ESS is characterized by installing and commissioning the most powerful proton LINear ACcelerator (LINAC) designed for neutron production and a 5MW Target system for the production of pulsed neutrons from spallation. The highly challenging and complex design of the Target and Neutron Scattering System (NSS) requires an in-depth analysis of the impact of the stringent manufacturing requirements and tight design tolerances. A campaign of several MECAmaster simulations was performed by ESS Target Division (TD) and Engineering and Integration Support (EIS) Division, focusing on those components that successively come close to their installation and are known for their criticality in terms of achieving the final installation tolerances. The aim of this current study is to investigate and statistically list the possibilities of eventual criticality on the assembly and installation processes, allowing for potential design optimization, tooling implementation and adjustment of the installation procedures.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST037  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 02 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOPT052 The Status of the In-Vacuum-APPLE II Undulator IVUE32 at HZB / BESSY II undulator, vacuum, photon, polarization 2716
 
  • J. Bahrdt, J. Bakos, S. Gaebel, S. Gottschlich, S. Grimmer, S. Knaack, C. Kuhn, F. Laube, A. Meseck, C. Rethfeldt, E.C.M. Rial, A. Rogosch-Opolka, M. Scheer, P.I. Volz
    HZB, Berlin, Germany
 
  At BESSY II, two new beamlines for RIXS and for X-Ray-microscopy demand a short period variably polarizing undulator. For this purpose, the first in-vacuum APPLE undulator worldwide is under construction. The parameters are as follows: period length=32mm, magnetic length=2500mm, minimum gap=7mm. The design incorporates a force compensation scheme as proposed by two of the authors at the SRI2018. All precision parts of the drive chain are located in air. New transverse slides for the transversal slit adjustment have been developed and tested. Optical micrometers measure the gap and shift positions, similar to the system of the CPMU17 at BESSY II. They provide the signals for motor feedback loops. A new UHV-compatible soldering technique, as developed with industry, relaxes fabrication tolerances of magnets and magnet holders and simplifies the magnet assembly. A 10-period prototype has been setup for lifetime tests of the new magnetic keeper design. The paper describes first results of the prototype and other key-components and summarizes the status of the full-scale undulator.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT052  
About • Received ※ 19 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 22 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOTK027 Temperature Dependent Effects on Quality Factor in C-band RF Cavities cavity, cryogenics, vacuum, electron 2826
 
  • J.R. Parsons, A. Fukasawa, G.E. Lawler, N. Majernik, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
 
  Funding: This work was supported by DOE Contract DE-SC0020409
Cryogenic operation and associated skin effects are encouraging fields of study for increasing RF gradients of beams within cavities and decreasing the required size for linear accelerators such as free electron lasers. Notably, a cavity’s RF quality factor Q, the ratio of the outgoing RF signal power to the input power, is theoretically multiplied by over 4 when subjected to cryogenic temperatures. Precise measurements of this Q factor require defining a cryostat unit, which consists of a high vacuum chamber, a coldhead, and MLI shielding. We optimized the cryostat by running several cool down tests at high vacuum, incorporating different geometries of MLI shielding to achieve the lowest possible temperatures. We then performed a low power C-band test after installing a cylindrical copper RF cavity to measure the Q factor. Finally, we improved stability and amplification within the chamber by installing edge welded bellows to the coldhead to reduce vibrations. These measurements provide a basis for the development of cryogenic infrastructure to sustain a cryogenic temperature environment for future RF applications.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK027  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 27 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOTK048 Radiation Load Studies for the FCC-ee Positron Source with a Superconducting Matching Device target, positron, collider, electron 2879
 
  • B. Humann
    TU Vienna, Wien, Austria
  • B. Auchmann, J. Kosse
    PSI, Villigen PSI, Switzerland
  • I. Chaikovska, S. Ogur
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • B. Humann, A. Latina, A. Lechner, Y. Zhao
    CERN, Meyrin, Switzerland
 
  For an electron-positron collider like FCC-ee, the production of positrons plays a crucial role. One of the design options considered for the FCC-ee positron source employs a superconducting solenoid made of HTS coils as an adiabatic matching device. The solenoid, which is placed around the production target, is needed to capture positrons before they can be accelerated in a linear accelerator. A superconducting solenoid yields a higher peak field than a conventional-normal conducting magnetic flux concentrator, therefore increasing the achievable positron yield. In order to achieve an acceptable positron production, the considered target is made of tungsten-rhenium, which gives also a significant flux of un-wanted secondary particles, that in turn could generate a too large radiation load on the superconducting coils. In this study, we assess the feasibility of such a positron source by studying the heat load and long-term radiation damage in the superconducting matching device and surrounding structures. Results are presented for different geometric configurations of the superconducting matching device.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK048  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOTK052 Muon Collider Graphite Target Studies and Demonstrator Layout Possibilities at CERN target, collider, proton, radiation 2895
 
  • F.J. Saura Esteban, M. Calviani, D. Calzolari, R. Franqueira Ximenes, A.M. Krainer, A. Lechner, R. Losito, D. Schulte
    CERN, Meyrin, Switzerland
  • C.T. Rogers
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
 
  Muon colliders offer enormous potential for research of the particle physics frontier. Leptons can be accelerated without suffering large synchrotron radiation losses. The International Muon Collider Collaboration is considering 3 and 10 TeV (CM) machines for a conceptual stage. In the core of the Muon Collider facility lays a MW class production target, which will absorb a high power (1 and 3 MW) proton beam to produce muons via pion decay. The target must withstand high dynamic thermal loads induced by 2 ns pulses at 5-50 Hz. Also, operational reliability must be guaranteed to reduce target exchanges to a minimum. Several technologies for these systems are being studied in different laboratories. We present in this paper the results of a preliminary feasibility study of a graphite-based target, and the different layouts under study for a demonstrator target complex at CERN. Synergies with advanced nuclear systems are being explored for the development of a liquid metal target.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK052  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 18 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOMS040 Present Status of Linear Accelerator System for Natural Rubber Vulcanization at Chiang Mai University radiation, electron, experiment, linac 3057
 
  • C. Thongbai, P. Jaikaew, E. Kongmon, S. Rimjaem, J. Saisut, P. Wongkummoon
    Chiang Mai University, Chiang Mai, Thailand
  • N. Khangrang
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M.W. Rhodes, S. Rimjaem, J. Saisut, C. Thongbai
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  At the Plasma and Beam Physics (PBP) Research Fa-cility, Chiang Mai University (CMU), an electron beam accelerator system for natural rubber irradiation has been under development and is currently under the commissioning. The research project is carried out with the aim to modify an old medical linac, retired from the clinical operation, for rubber latex vulcanization and materials irradiation using electron beams. The accelerator system consists of a DC-thermionic cathode electron gun, a standing-wave RF linear accelerator, an RF system, a control system, beam diagnostic systems, and an irradia-tion system. The components were completely assembled, and the RF system was tested. The RF processing has been performed and some of the electron beam properties have been measured. This contribution presents some experimental results while developing and testing the various sub-systems of this accelerator. The present status of development and some vulcanization results will also be reported in this contribution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS040  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 04 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOMS047 Design of Radiation Shielding for the PBP-CMU Electron Linac Laboratory radiation, electron, photon, neutron 3073
 
  • P. Jaikaew, N. Khangrang
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
  • S. Rimjaem
    Chiang Mai University, Chiang Mai, Thailand
  • S. Rimjaem
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  The local radiation shielding is designed for the electron linear accelerator beam dump at the PBP-CMU Electron Linac Laboratory (PCELL) with the aim to control the annual ambient dose equivalent during the operation. The study of radiation generation and design of radiation shielding is conducted based on the Monte Carlo simulation toolkit GEANT4. The study results include an annual ambient dose equivalent map and design of local shielding for the first bam dump downstream the linac section. With this design, the leaking radiation outside the accelerator hall is completely blocked and the average annual ambient dose equivalent on the rooftop of the hall is within the IAEA safety limit for the supervised area. The shielding model will then be used as a guideline for the construction in the near future.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS047  
About • Received ※ 07 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 15 June 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOMS052 Magnetic Field Shield for SC-Cavity with Thin Nb Sheet cavity, niobium, experiment, cryogenics 3090
 
  • Y. Iwashita, Y. Kuriyama
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • Y. Fuwa
    JAEA/J-PARC, Tokai-mura, Japan
  • H. Tongu
    Kyoto ICR, Uji, Kyoto, Japan
 
  Funding: This work was partly supported by JSPS KAKENHI Grant Number 19K21877.
Shielding the superconducting accelerating cavity made of niobium from the weak environmental magnetic field is an important subject. Niobium is a type-II superconductor, which traps the environmental magnetic flux in the material during the superconducting transition, resulting in increase of residual resistance and heating during operation during operation. Shielding from a weak magnetic field is essential for high performance operations. A magnetic shielding method that uses the diamagnetism of superconducting materials instead of magnetic flux absorption by high magnetic permeability materials is discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS052  
About • Received ※ 14 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 18 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)