S. Nagaitsev, A.L. Romanov, A.V. Shemyakin, G. Stancari
Fermilab, Batavia, Illinois, USA
Funding:The work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Two experiments were carried out to study the statistical properties of undulator radiation in the Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab. The first experiment studied the turn-to-turn fluctuations in the power of the radiation generated by an electron bunch. The magnitude of these fluctuations depends on the 6D phase-space distribution of the electron bunch. In IOTA, we demonstrated that this effect can be used to measure some electron bunch parameters, small transverse emittances in particular. In the second experiment, a single electron was stored in the ring, emitting a photon only once per several hundred turns. In this regime, any classical interference-related collective effects were eliminated, and the quantum fluctuations could be studied in detail to search for possible deviations from the expected Poissonian photon statistics. In addition, the photocount arrival times were used to track the longitudinal motion of a single electron and to compare it with simulations. This allowed us to determine several dynamical parameters of the storage ring such as the rf cavity phase jitter and the dependence of the synchrotron motion period on amplitude.
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F. Fienga, G. Breglio, A. Irace, V.R. Marrazzo, L. Sito
University of Napoli Federico II, Napoli, Italy
N. Beni, G. Breglio, S. Buontempo, F. Carra, F. Fienga, F. Giordano, V.R. Marrazzo, B. Salvant, L. Sito, Z. Szillasi
CERN, Meyrin, Switzerland
N. Beni, Z. Szillasi
Atomki, Debrecen, Hungary
S. Buontempo
INFN-Napoli, Napoli, Italy
The passage of a high-intensity particle beam inside accelerator components generates heating, potentially leading to degradation of the accelerator performance or damage to the component itself. It is therefore essential to monitor such beam-induced heating in accelerators. This paper showcases the capabilities of iPipe, which is a set of Fiber Bragg Grating sensors stuck on the inner beam pipe of the Compact Muon Solenoid (CMS) experiment installed in the CERN Large Hadron Collider (LHC). In this study, the wavelength shift, linked directly to the temperature shift, is measured and is compared with the computed dissipated power for a set of LHC fills. Electromagnetic and thermal simulations were also coupled to predict the beam-induced temperature increase along the beam pipe. These results further validate the sensing system and the methods used to design accelerator components to mitigate beam-induced heating.
R.L. Hermann, M. Galonska, Th. Haberer, A. Peters
HIT, Heidelberg, Germany
T. Gehrke
German Cancer Research Center (DKFZ), Heidelberg, Germany
B. Leverington
Universität Heidelberg, Heidelberg, Germany
Funding:Funded by Deutsche Forschungsgemeinschaft (DFG), project number 426970603. The Heidelberg Ion-Beam Therapy Center (HIT) pro-vides proton, helium, and carbon-ion beams with differ-ent energies and intensities for cancer treatment and oxy-gen-ion beams for experimentation. Below the intensities used for therapy, low-intensity ion beams (below 1·105 ions/s) are available for various experiments via manual-ly degrading of the beam. Since there is no built-in beam profile instrumentation device for this intensity region, the development of a transverse ion beam profile monitor for these intensities is therefore of interest. The principle of operation is based on scintillating fibres, particularly those with enhanced radiation hardness. The fibres transform the deposited energy of a traversing ion into photons, which are then converted and amplified via silicon pho-tomultipliers (SiPMs) into electric pulses. These pulses are recorded and processed by a novel and dedicated readout electronics: the front-end readout system (FERS) A5200 by CAEN. A prototype set-up consisting of all the above-mentioned parts was tested in beam and has proven to record the transverse beam profile successfully from intensities of 1·107 ions/s down to 1·102 ions/s.
C. Thiebaux, L. Bernardi, F. Gastaldi, Y. Geerebaert, R. Guillaumat, F. Magniette, P. Manigot, M. Verderi
LLR, Palaiseau, France
É. Delagnes, F.T. Gebreyohannes, O. Gevin
CEA-IRFU, Gif-sur-Yvette, France
F. Haddad, N. Servagent
SUBATECH, Nantes, France
F. Haddad, C. Koumeir, F. Poirier
Cyclotron ARRONAX, Saint-Herblain, France
Funding:This study is supported by two programs of the Agence Nationale de la Recherche, ANR-17-CE31-0015 and ANR-11-EQPX-0004. The PEPITES project* consists of a brand new operational prototype of an ultra-thin, radiation-resistant profiler capable of continuous operation on mid-energy (O(100 MeV)) charged particle accelerators. Secondary electron emission (SEE) is used for the signal because it only requires a small amount of material (10 nm); very linear, it also offers good dynamics. The lateral beam profile is sampled using segmented electrodes, constructed by thin film methods. Gold strips, as thin as the electrical conductivity allows (~ 50 nm), are deposited on an insulating substrate as thin as possible. While crossing the gold, the beam ejects the electrons by SEE, the current thus formed in each strip allows the sampling. SEE was characterized at ARRONAX with 68 MeV proton beams and at medical energies at CPO**. Electrodes were subjected to doses of up to 109 Gy without showing significant degradation. A demonstrator with dedicated electronics (CEA) is installed at ARRONAX and will be used routinely with proton beams of 17-68 MeV for intensities of 100fA to 100nA. An overview of the design and first measurements will be presented, and system performances will be assessed. *LLR, ARRONAX cyclotron and CEA **Orsay Protontherapy Center (Institut Curie)
D. Butti, E. Bravin, G. Trad
CERN, Meyrin, Switzerland
S.M. Gibson
Royal Holloway, University of London, Surrey, United Kingdom
At the CERN Large Hadron Collider (LHC), among the different systems exploiting Synchrotron Radiation (SR) for beam diagnostics, interferometry is under study as a non-invasive technique for measuring absolute beam transverse sizes. Extensive numerical simulations, recently completed for characterising the spatial coherence of the LHC SR source, facilitated the optimisation of the LHC interferometer design and the existing prototype system tested in the past has been refurbished to include the new simulation findings. This contribution describes the simulation specificity and then focuses on first measurements performed at the beginning of the LHC run 3. Such experiments allowed to obtain a first validation of the expected system performance at the injection energy of 450 GeV. A complete benchmark of the simulations will be carried out in 2022 as soon as the LHC will reach its top energy of 6.8 TeV.
S. Maier, M. Brosi, H.J. Cha, A. Mochihashi, A.-S. Müller, M.J. Nasse, P. Schreiber, M. Schwarz
KIT, Karlsruhe, Germany
Funding:Supported by the DFG project 431704792 in the ANR-DFG collaboration project ULTRASYNC and by the Doctoral School KSETA. Two parallel, corrugated plates will be installed at the KIT storage ring KARA (KArlsruhe Research Accelerator). This impedance manipulation structure can be used to study and eventually control the electron beam dynamics and the emitted coherent synchrotron radiation (CSR) at KARA. In this contribution, we present the design of the impedance manipulation structure with corrugated plates, simulation results showing the influence of different corrugation parameters on its impedance, and the impact of this additional impedance source on the temporal changes in the emitted CSR in the presence of the microbunching instability.
A.B. Barboutis, R. Klein, M. Müller
PTB, Berlin, Germany
The electron storage ring MLS (Metrology Light Source) is used by the Physikalisch-Technische Bundesanstalt (PTB), the German metrology institute, as a primary source standard of calculable synchrotron radiation in the ultraviolet and vacuum ultraviolet spectral range. For this, all storage ring parameters have to be appropriately set and measured with high uncertainty. E.g., the electron beam current can be varied by more than 11 orders. This adjustment of the electron beam current, and thus the spectral radiant intensity of the synchrotron radiation, for the specific calibration task is conveniently performed fully automatic by a computer program.
P. Ilinski
MAX IV Laboratory, Lund University, Lund, Sweden
Funding:Research conducted at MAX IV, a Swedish national user facility, is supported by the Swedish Research council, the Swedish Governmental Agency for Innovation Systems, and Formas. A novel photoemission type of X-ray Beam Position Monitor (XBPM) for the ’white’ undulator radiation is proposed. The XBPM employs beamline frontend fixed mask as a source of photocurrent signal. Signal spatial distribution and XBPM response were analyzed for various undulator radiation parameters.
S. Mazzoni, W. Andreazza, E. Balci, D. Belohrad, E. Bravin, N.S. Chritin, J.C. Esteban Felipe, T. Lefèvre, M. Martin Nieto, M. Palm
CERN, Meyrin, Switzerland
The Beam Rate of Neutrals (BRAN) is a monitor that provides a relative luminosity measurement for the four LHC experiments. BRANs are used during operations as a tool to find and optimise collision and to cross-check experiments luminosity monitors. While each LHC experiments is equipped with BRANs, in this contribution we will focus on the new monitors installed for ATLAS and CMS that will replace the current ageing gas chambers during LHC run 3. These will also serve as as prototypes for the future High Luminosity LHC monitors that will need to sustain an even higher collision rate. A description of the BRAN as well as the first results obtained during the LHC Run 3 start-up will be presented.
H. Aoyagi, T. Fujita, K. Kobayashi, H. Osawa, S. Takahashi
JASRI/SPring-8, Hyogo, Japan
Funding:This work is partly supported by Japan Society for the Promotion of Science through a Grant-in-Aid for Scientific Research (c), No.18K11943, 21K12530. This study analyzes a pulse-mode x-ray beam position monitor that enables pulse-by-pulse position measurement in a synchrotron radiation beamline of the synchrotron radiation facility, SPring-8. The monitor is equipped with blade-shaped detection elements utilizing diamond heatsinks to reduce stray capacitance and a microstripline transmission line to improve high-frequency characteristics. The detection elements operate as photocathodes and generate single unipolar pulses with a full width at half-maximum of less than 1 ns, allowing pulse-by-pulse measurement of the synchrotron radiation beam. We confirmed the basic operation of the monitor at the SPring-8 bending magnet beamline*. The detection element’s heat resistance consequently improved. An evaluation test was carried out at the SPring-8 undulator beamline with significantly high synchrotron radiation intensity. We aim to report the evaluation results of the sensitivity and resolution of the monitor measured by exciting a betatron oscillation in the horizontal/vertical direction using beam shakers of the SPring-8 storage ring and the observation results of the pulse-by-pulse photon beam dynamics induced by beam injection. * https://journals.aps.org/prab/pdf/10.1103/PhysRevAccelBeams.24.032803
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M. Marich, S. Carrato
University of Trieste, Trieste, Italy
L. Bosisio, A. Gabrielli, Y. Jin, L. Lanceri
INFN-Trieste, Trieste, Italy
G. Brajnik, G. Cautero, D. Giuressi
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
L. Vitale
Università degli Studi di Trieste, Trieste, Italy
Regardless of the different accelerator types (light sources like FELs or synchrotrons, high energy colliders), diagnostics is an essential element for both personnel and machine protection. With each update, accelerators become more complex and require an appropriate diagnostic system capable of satisfying multiple specifications, that become more stringent as complexity increases. This paper presents prototyping work towards a possible update of the readout electronics of a system based on single-crystal chemical vapor deposition (scCVD) diamond sensors, monitoring the radiation dose-rates in the interaction region of SuperKEKB, an asymmetric-energy electron-positron collider. The present readout units digitize the output signals from the radiation monitors, process them using an FPGA, and alert the accelerator control system if the radiation reaches excessive levels. The proposed updated version introduces a new design for the analog front end that overcomes its predecessor’s limits in dynamic range thanks to high-speed switches to introduce a variable gain in transimpedance preamplifiers, controlled by an ad-hoc developed FPGA firmware.
R. Kwiatkowski, R. Nietubyc, J. Szewiński, D.R. Zaloga
NCBJ, Świerk/Otwock, Poland
A.I. Wawrzyniak
NSRC SOLARIS, Kraków, Poland
Funding:European Regional Development Fund in the framework of the Smart Growth Operational Programme and Regional Operational Programme for Mazowieckie Voivodeship. The Beam Loss Monitor (BLM) system is primarily used for machine protection and is especially important in the case of high energy density of accelerated beam, when such a beam could cause serious damages due to uncontrolled loss. PolFEL linear accelerator is designed with the beam parameters, which made BLM an essential system for machine protection. The design of BLM system for PolFEL is composed of several scintillation probes placed along and around the accelerator. The paper reports on design and first tests of prototype detector, which is planned to be used for PolFEL project. The prototype was tested in NCBJ and SOLARIS, using radioactive calibration samples and linear electron accelerator as a sources. We also present results of numerical investigation of radiation generated due to interaction of fast electrons with accelerator components.
H. Guerin, R. De Maria, R. Kersevan, B. Kolbinger, T. Lefèvre, M.T. Ramos Garcia, B. Salvant, G. Schneider, J.W. Storey
CERN, Meyrin, Switzerland
S.M. Gibson, H. Guerin
Royal Holloway, University of London, Surrey, United Kingdom
The Beam Gas Vertex (BGV) instrument is a novel non-invasive transverse beam profile monitor under development for the High Luminosity Upgrade of the Large Hadron Collider (HL-LHC). Its principle is based on the reconstruction of the tracks and vertices issued from beam-gas inelastic hadronic interactions. The instrument is currently in the design phase, and will consist of a gas target, a forward tracking detector installed outside the beam vacuum chamber and computing resources dedicated to event reconstruction. The transverse beam profile image will then be inferred from the spatial distribution of the reconstructed vertices. With this method, the BGV should be able to provide bunch-by-bunch measurement of the beam size, together with a beam profile image throughout the whole LHC energy cycle, and independently of the beam intensity. This contribution describes the design of the gas target system and of the gas tank of the future instrument.
M. Siano
Università degli Studi di Milano, Milano, Italy
D. Butti, T. Lefèvre, S. Mazzoni, G. Trad
CERN, Meyrin, Switzerland
G. Geloni
EuXFEL, Schenefeld, Germany
U. Iriso, A.A. Nosych, L. Torino
ALBA-CELLS, Cerdanyola del Vallès, Spain
B. Paroli, M.A.C. Potenza
Universita’ degli Studi di Milano & INFN, Milano, Italy
"Fast Monte-CarlO approach to Coherence of Undulator Sources" (FOCUS) is a new GPU-based code to compute the transverse coherence of X-ray radiation from undulator sources. The code relies on scaled dimensionless quantities and analytic expressions of the electric field emitted by electrons in an undulator, obtained in the frequency domain under paraxial approximation (justified by the assumption of ultra-relativistic electrons) and free space propagation, with the addition of the resonance approximation. We describe the core structure of the code, which exploits GPUs for massively parallel computations. We validate our approach by direct comparison with SRW (Synchrotron Radiation Workshop) simulations. The benchmarks prove that FOCUS yields similar results with respect to SRW, while at the same time reducing the computation times by five orders of magnitude. Finally, we show examples of applications to beam size diagnostics. The aim of the code is to fast evaluating the transverse coherence properties of undulator X-ray radiation as a function of the electron beam parameters, and to support and help preparing more rigorous numerical simulations with traditional codes like SRW.
O. Sedláček, M. Ady, C. Castro Sequeiro, A.R. Churchman, S. Mazzoni, G. Schneider, K. Sidorowski, R. Veness
CERN, Meyrin, Switzerland
P. Forck, S. Udrea
GSI, Darmstadt, Germany
M. Sameed
European Organization for Nuclear Research (CERN), Geneva, Switzerland
O. Sedláček, O. Stringer, C.P. Welsch, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom
O. Sedláček, O. Stringer, C.P. Welsch, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom
In a gas jet monitor, a supersonic gas curtain is injected into the beam pipe and interacts with the charged particle beam. The monitor exploits fluorescence induced by beam-gas interactions, thus providing a minimally invasive transverse profile measurement. Such a monitor is being developed as part of the High Luminosity LHC upgrade at CERN. As a preliminary study, the fluorescence cross section of relevant gases must be measured for protons at 450 GeV and 6.8 TeV (i.e. the LHC injection and flat top energies). In these measurements, neon, or alternatively nitrogen gas, will be injected into the LHC vacuum pipe by a regulated gas valve to create an extended pressure bump. This work presents the optical detection system that was installed in 2022 in the LHC to measure luminescence cross-section and horizontal beam profile. Preliminary measurements of background light and first signals are presented in this paper.
M. Labat, A. Bence, A. Berlioux, B. Capitanio, G. Cauchon, J. Da Silva, N. Hubert, D. Pédeau, M. Thomasset
SOLEIL, Gif-sur-Yvette, France
SOLEIL storage ring is presently equipped with three diagnostics beamlines: two in the X-ray range (pinhole cameras) and one in the visible range. The visible range beamline relies on a slotted copper mirror extracting the synchrotron radiation from one of the ring dipoles. The extracted radiation is then transported down to a dedicated hutch in the experimental hall. Up to now, this radiation was split into three branches for rough monitoring of the beam transverse stability, bunch length measurements and filling pattern measurements. In the framework of SOLEIL’s upgrade, we now aim at developing a new branch for high resolution beam size measurement using polarized imaging. This work presents the various modifications recently achieved on the beamline to reach this target, including a replacement of the extraction mirror, and preliminary results towards transverse beam size measurement.
K. Łasocha
Jagiellonian University, Kraków, Poland
For the needs of diagnostics of the longitudinal electron beam characteristics at the first Polish free electron laser (PolFEL) project, a Coherent Diffraction Radiation (CDR) system is being developed and tested. It will allow for nondestructive bunch length measurement based on the power balance of CDR radiation collected by Schottky diodes in different ranges of sub-THz radiation. The first tests and measurements will be performed at the end of the Solaris synchrotron injector linac, where the beam profile is already known from previous studies. In addition the camera system with automatic focus was developed and tested. In this contribution the theoretical background of the measurement, calculations and first experimental steps will be presented.
M. Saifulin, C. Trautmann
TU Darmstadt, Darmstadt, Germany
P. Boutachkov, M. Saifulin, C. Trautmann, B. Walasek-Höhne
GSI, Darmstadt, Germany
E.I. Gorokhova
GOI, St Petersburg, Russia
P. Rodnyi, I.D. Venevtsev
SPbPU, St. Petersburg, Russia
Funding:DLR financed this research within the framework of the ERA. Net RUS Plus Project RUSST2017-051 ZnO-based ceramics are known as promising scintillators exhibiting light emission in the ultraviolet (UV) spectral region (~390 nm) and ultrafast decay times (<1 ns). They are of great interest for applications in scintillation counters and screens at high-energy heavy ion accelerators. In this contribution, the deterioration of scintillating properties of ZnO-based ceramics subjected to heavy ion exposure at high doses is investigated. The scintillation light spectra of ZnO(In) as a function of fluence for 4.8 MeV/u 48Ca and 197Au ions were studied. We observed that the deterioration of the scintillation intensity with increasing fluence follows the Birks-Black model. * The results presented in this contribution are based on the work performed before the 24th of February, 2022. ** m.saifulin@gsi.de (corresponding author)
L. Torino, G. Benedetti, F.F.B. Fernández, U. Iriso, Z. Martí, J. Moldes, D. Yépez
ALBA-CELLS, Cerdanyola del Vallès, Spain
The polarization of the synchrotron radiation produced by a bending magnet can be selected by properly choosing the vertical emission angle. At beamlines this can be done by moving a slit to cut out unwanted polarization: this method is time consuming and not very reproducible. Another option is to fix the slit position and generate a local bump with the electron beam, and vary the emission angle at the source point such that the slit is illuminated with the desired polarization. At ALBA, we have implemented this option within the Fast Orbit Feedback, which allows to perform the angle switch in less than one minute without affecting the other beamlines. This report describes the implementation of this technique for the dipole beamline MISTRAL at the ALBA Synchrotron.
The demonstrations of GeV electron beams and FEL radiation driven by a centimeter-scale device illustrate the tremendous progress of laser-plasma accelerators. In such applications, beam divergence and size, along with beam energy and charge, are critical parameters of electron beams. An insight on the transverse parameters and their dynamics such as beam decoherence can be obtained by diagnostics complemented by betatron radiation detectors. This talk will also provide a brief overview of recent techniques for accessing the transverse phase space.
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D.S. Levin, C. Ferretti, A. Kaipainen, N.A. Ristow
University of Michigan, Ann Arbor, Michigan, USA
P.S. Friedman
Integrated Sensors, LLC, Ottawa Hills, Ohio, USA
T.N. Ginter
NSCL, East Lansing, Michigan, USA
Funding:This work is funded by SBIR Phase-II Award No. DE-SC0019597, DOE Office of Science to Integrated Sensors, LLC. A high performance Scintillator Ion Beam Monitor (SBM)provides diagnostics across a range of isotopes, energies, and intensities. It uses a machine-vision camera and a magazine of thin scintillators, movable into the beam without breaking vacuum. Two proprietary scintillators are used: a semicrystalline polymer material (PM) tested over a thickness range of ~1 to 190 µm. The PM yields stronger signals than other commercial plastic scintillators tested and is radiation damage resistant; a 100-400 µm opaque wafer consisting of inorganic crystals in a polymer hybrid matrix (HM). Both PM and HM are non-hygroscopic and produce minimal secondary reflections. HM produces significantly larger signals than CsI with excellent radiation damage resistance. The SBM was staged at the FRIB (East Lansing) ion beam, demonstrating real-time beam profile and rate analysis spanning more than five orders-of-magnitude including visualization of single ion signals with ~10-20 µm spatial resolution. It is superior to and may replace the reference detectors: Faraday cup, silicon strips and a CCD camera beam imager. A proton test beam extended the dynamic range by four orders-of-magnitude.
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Currently developed nuclear accelerators more and more widely use superconducting elements especially in windings of superconducting electromagnets and current leads to them. These elements are however sensitive to the irradiation caused by primary beam as well as by secondary particles, as it is the case for PolFEL. In the paper it is discussed how this irradiation damages the subtle structure of superconducting materials, leading to columnar defects formation in 2D HTc superconductors. It is analysed, in which way created nano-sized structural defects influence the critical current properties of the superconducting materials, in the process of capturing of the magnetic pancake vortices. Various initial positions of the captured vortices are analysed; their movement leads to potential barrier variations. Influence of the irradiation effects on the current-voltage characteristics of superconductors are investigated then and maximal current density detected as the function of irradiation dose, nano-defects size and physical parameters as magnetic field and temperature.
U. Iriso, A.A. Nosych, M. Zeus
ALBA-CELLS, Cerdanyola del Vallès, Spain
A.C. Cazorla
ICMAB, Bellatera, Spain
I. Mases Solé
CERN, Meyrin, Switzerland
ALBA is currently equipped with two x-ray pinhole cameras for continuous beam size monitoring using the synchrotron radiation from two different bending magnets. The first pinhole was installed in day-1 and it is working properly since 2012 as the work-horse for the ALBA emittance measurements, while the second one has been commissioned in beginning 2021 for redundancy purposes. This paper summarizes the exercises to characterize the Point Spread Function (PSF) of both pinhole cameras using analytical calculations, SRW simulations, and experimental measurements using the beam lifetime.
M. Marongiu, G. Kube, M. Lantschner, A.I. Novokshonov, K. Wittenburg
DESY, Hamburg, Germany
The PETRA IV project will be a Diffraction Limited Light Source designed to be the successor of PETRA III, the 6 GeV 3rd generation hard X-Ray synchrotron light source at DESY in Hamburg. It will operate at a beam energy of 6 GeV with a design emittance of 20/4 pm rad. For a precise emittance online control, two dedicated diagnostics beamlines will be built up to image the beam profile with synchrotron radiation in the X-Ray region. With two beamlines, it will be possible to extract both the transverse beam emittances and the beam energy spread. Both beamlines will be equipped with two interchangeable X-Ray optical systems: a pinhole camera system to achieve high dynamic range and a Fresnel Diffractometry system for high resolution measurements in the range 1-18 um. This paper describes the planned setup and deals with the possible limitations.
C. Davut
The University of Manchester, Manchester, United Kingdom
Ö. Apsimon
The University of Liverpool, Liverpool, United Kingdom
P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
T. Lefèvre, S. Mazzoni
CERN, Meyrin, Switzerland
G.X. Xia
UMAN, Manchester, United Kingdom
In this paper, a study using the Polarization Current Approach (PCA) model is performed to optimize the design of a short bunch length monitor using two dielectric radiators that produce coherent Cherenkov Diffraction Radiation (ChDR). The electromagnetic power emitted from each radiator is measuring a different part of the bunch spectrum using Schottky diodes. For various bunch lengths, the coherent ChDR spectrums are calculated to find the most suitable frequency bands for the detection system. ChDR intensities measured by each detector are estimated for different impact parameters to explore the dependence of bunch length monitor on beam position and angular jitter. It is found that, in the present configuration, the effects of beam position and angular jitter are negligibly small for bunch length measurement. * Shevelev, M. V., & Konkov, A. S. (2014). Journal of Experimental and Theoretical Physics, 118(4), 501-511. ** Curcio, A. et al. (2020). Physical Review Accelerators and Beams, 23(2), 022802.
P. Boutachkov, M. Saifulin, C. Trautmann, B. Walasek-Höhne
GSI, Darmstadt, Germany
E.I. Gorokhova
GOI, St Petersburg, Russia
P. Rodnyi, I.D. Venevtsev
SPbPU, St. Petersburg, Russia
Novel radiation-hard scintillators were developed in the last years based on indium-doped ZnO ceramic with an extremely short decay time below a ns. Fast counting detectors and fast screens were considered as potential beam diagnostic applications of this material. At the GSI/FAIR facility, scintillation detectors are commonly used for measuring the intensity and detailed time structure of relativistic heavy ion beams. The scintillating material is inserted directly into the beam path. Signals from individual ions are counted, providing systematic-error-free beam intensity information. Standard scintillators require frequent maintenance due to radiation damage. To address this limitation, a large area ZnO radiation-hard detector was developed. The prototype detector operates at orders of magnitude higher irradiation levels, at higher counting rates and has better time resolution compared to a plastic scintillator. In addition, the novel detector material opens the possibilities for applications in other beam diagnostic systems, for example, scintillation screens for transverse profile measurements. Therefore, ZnO scintillation ceramics are of general interest for beam diagnostics.
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P. Casolaro, S. Braccini, G. Dellepiane, A. Gottstein, I. Mateu, P. Scampoli
AEC, Bern, Switzerland
P. Scampoli
Naples University Federico II, Napoli, Italy
Funding:This project was partially funded by the Bern Center for Precision Medicine (BCPM) of the University of Bern, and by the Swiss National Science Foundation (SNSF) [Grant: CRSII5180352] A new radiotherapy modality, known as FLASH, is a potential breakthrough in cancer care as it features a reduced damage to healthy tissues, resulting in the enhancement of the clinical benefit. FLASH irradiations are characterized by ultra-high dose-rates (>40 Gy/s) delivered in fractions of a second. This represents a challenge in terms of beam diagnostics and dosimetry, as detectors used in conventional radiotherapy saturate or they are too slow for the FLASH regime. In view of the FLASH clinical translation, the development of new dosimeters is fundamental. Along this line, a research project is ongoing at the University of Bern aiming at setting-up new beam monitors and dosimeters for FLASH. The proposed detection system features millimeter scintillators coupled to optical fibers, transporting light pulses to a fast photodetector, readout by high bandwidth digitizers. First prototypes were exposed to the 18 MeV proton beam at the Bern medical cyclotron. The new detectors have been found to be linear in the range up to 780 Gy/s, with a maximum time resolution of 100 ns. These characteristics are promising for the development of a new class of detectors for FLASH radiotherapy.
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A. Mariet, B. Moser, R. Veness
CERN, Meyrin, Switzerland
M. Devel, J.E. Groetz
UFC, Besançon, France
A. Mikhalchan, J.J. Vilatela
IMDEA, Madrid, Spain
With the planned increase of luminosity at CERN for HL-LHC and FCC, instruments for beam quality control must meet new challenges. The current wires, made up of plain carbon fibers and gold-plated tungsten would be damaged due to their interactions with the higher luminosity beams. We are currently testing a new and innovative material, with improved performance: carbon nanotube fibers (CNTF). The HiRadMat (High Radiation for Material) experimental line at the output of the SPS is a user facility which can irradiate fix targets up to 440 GeV/c. CNTF with various diameters were irradiated in HiRadMat with different intensities, later imaged with a SEM microscope and tested for their mechanical properties. In addition, simulations have been carried out with the FLUKA particle physics Monte-Carlo code, in order to better understand the mechanisms and assess the energy deposition from protons at 440 GeV/c in those CNTF wires, depending mainly on their diameters and densities. This could lead to a good estimation of the CNTF temperature during irradiation. In this contribution, we first present the HiRadMat experimental setup and then we discuss the results of our FLUKA simulations.
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