Keyword: betatron
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MOPLXGD3 The Accelerator and Beam Physics of the Muon g-2 Experiment at Fermilab storage-ring, experiment, positron, lattice 10
 
  • D.A. Tarazona
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  The physics case of the Muon g-2 Experiment at Fermilab is outstanding and has recently attracted significant attention from its first official results. Although its measurements involve high energy physics methods, such as counting positron production rates with the use of calorimeters and beam diagnostics with tracking detectors, this experiment is strongly bound to accelerator and beam physics. This paper reviews the principles of the experiment and the details necessary to provide a solid ground for the beam-dynamics uncertainties and the corrections of the systematic effects influencing the output of the experiment: a single numerical value, which may unveil new physics.  
slides icon Slides MOPLXGD3 [29.311 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPLXGD3  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 09 July 2022
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MOPOST033 Betatron Tune Characterization of the Rutgers 12-Inch Cyclotron for Different Magnetic Poles Configurations focusing, cyclotron, HOM, experiment 136
 
  • C. Hernalsteens
    CERN, Meyrin, Switzerland
  • B.L. Beaudoin, T.W. Koeth
    UMD, College Park, Maryland, USA
  • M. Miller
    Brown University, Providence, USA
  • T.S. Ponter
    IBA, Louvain-la-Neuve, Belgium
  • K.J. Ruisard
    ORNL, Oak Ridge, Tennessee, USA
  • R. Tesse
    ULB, Bruxelles, Belgium
 
  The Rutgers cyclotron is a small 12-Inch, 1.2MeV proton cyclotron. Sets of magnet pole-tips were designed to demonstrate different cyclotron focusing options: weak focusing, radial sector focusing and spiral sector focusing. The purpose of this paper is to experimentally characterize the transverse dynamics provided by different types of focusing. Magnetic field measurements provide insight into the as-built properties of these magnetic poles configurations. First we discuss the axial betatron tune measurements as a function of the beam energy towards outer radii, which agree well with the values expected from measured magnetic data. Turn-by-turn betatron envelope oscillation measurements are also reported and compared with the tune measurements. Excellent agreement is once again found.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST033  
About • Received ※ 09 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 08 July 2022
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MOPOPT011 Transverse Excitation and Applications for Beam Control resonance, extraction, controls, simulation 251
 
  • P.J. Niedermayer, R. Singh
    GSI, Darmstadt, Germany
 
  Transverse excitation of stored particle beams is required for a number of applications in accelerators. Using a time-varying, transverse electric field with a dedicated frequency spectrum, the amplitude and coherence of betatron oscillations can be increased in a controlled manner. This allows for determination of the betatron tune from turn-by-turn position measurements, control of transverse beam shapes, as well as extraction of stored beams. For studies of beam excitation, a custom signal generator is being developed. It is based on software-defined radio (SDR) which allows for configurable signal characteristics and tuneable spectra. This approach enables usage for multiple applications in beam diagnostics and control. To determine appropriate excitation spectra, studies of particle dynamics in presence of excitation are being carried out. Nonlinear fields are also incorporated to account for beam extraction conditions, which affects frequency spectra of beam motion due to detuning effects.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT011  
About • Received ※ 30 May 2022 — Accepted ※ 10 June 2022 — Issue date ※ 16 June 2022  
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MOPOPT063 Reconstruction of Beam Parameters from Betatron Radiation Using Maximum Likelihood Estimation and Machine Learning radiation, simulation, diagnostics, beam-diagnostic 407
 
  • S. Zhang, G. Andonian, C.E. Hansel, P. Manwani, B. Naranjo, M.H. Oruganti, J.B. Rosenzweig, M. Yadav
    UCLA, Los Angeles, California, USA
  • Ö. Apsimon, C.P. Welsch, M. Yadav
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: US Department of Energy, Division of High Energy Physics, Contract No. DE-SC0009914 STFC Liver-pool Centre for Doctoral Training on Data Intensive Science, grant agreement ST/P006752/1
Betatron radiation that arises during plasma wakefield acceleration can be measured by a UCLA-built Compton spectrometer, which records the energy and angular position of incoming photons. Because information about the properties of the beam is encoded in the betatron radiation, measurements of the radiation can be used to reconstruct beam parameters. One method of extracting information about beam parameters from measurements of radiation is maximum likelihood estimation (MLE), a statistical technique which is used to determine unknown parameters from a distribution of observed data. In addition, machine learning methods, which are increasingly being implemented for different fields of beam diagnostics, can also be applied. We assess the ability of both MLE and other machine learning methods to accurately extract beam parameters from measurements.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT063  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 24 June 2022 — Issue date ※ 26 June 2022
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TUPOST037 Reconstruction of Transverse Phase Space From Transverse Feedback Data for Real Time Extraction of Vital LHC Machine Parameters feedback, pick-up, real-time, injection 937
 
  • G. Kotzian, M.E. Soderen, P.S. Solvang, D. Valuch
    CERN, Meyrin, Switzerland
  • V. Stopjakova
    Slovak University of Technology (STU), Faculty of Electrical Engineering and Information Technology, Bratislava, Slovak Republic
 
  The LHC transverse feedback system (ADT) provides bunch by bunch, turn by turn, normalized and digitized beam position signals from four pick-ups per plane and for each beam. Together with already existing powerful computer-based observation systems, this data can be used to reconstruct in real-time the transverse phase space coordinates of the centre-of-charges, for each individual bunch. Such information is extremely valuable for machine operation, or transverse instability diagnostics. This paper aims on discussing and evaluating methods of combining four position signals for such analysis in the presence of noise and with active transverse feedback. Comparisons are made based on the extraction of vital parameters like the fractional tune or transverse activity. Analytical and numerical results are further benchmarked against real beam data.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST037  
About • Received ※ 20 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 04 July 2022
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WEPOST015 Implementation of a Tune Sweep Slow Extraction with Constant Optics at MedAustron extraction, simulation, operation, optics 1715
 
  • P.A. Arrutia Sota, M.A. Fraser, B. Goddard, V. Kain, F.M. Velotti
    CERN, Meyrin, Switzerland
  • P. Burrows
    JAI, Oxford, United Kingdom
  • A. De Franco
    QST Rokkasho, Aomori, Japan
  • F. Kuehteubl, M.T.F. Pivi, D.A. Prokopovich
    EBG MedAustron, Wr. Neustadt, Austria
 
  Conventional slow extraction driven by a tune sweep perturbs the optics and changes the presentation of the beam separatrix to the extraction septum during the spill. The constant optics slow extraction (COSE) technique, recently developed and deployed operationally at the CERN Super Proton Synchrotron to reduce beam loss on the extraction septum, was implemented at MedAustron to facilitate extraction with a tune sweep of operational beam quality. COSE fixes the optics of the extracted beam by scaling all machine settings with the beam rigidity following the extracted beam’s momentum. In this contribution the implementation of the COSE extraction technique is described before it is compared to the conventional tune sweep and operational betatron core driven cases using both simulations and recent measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST015  
About • Received ※ 07 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 18 June 2022
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WEPOST019 Benchmarks of Energy Deposition Studies for Heavy-Ion Collimation Losses at the LHC collimation, simulation, heavy-ion, operation 1730
 
  • J.B. Potoine, R. Bruce, R. Cai, P.D. Hermes, A. Lechner, S. Redaelli, A. Waets
    CERN, Meyrin, Switzerland
  • F. Wrobel
    IES, Montpellier, France
 
  During some periods in its second physics run (2015-2018), the LHC has been operated with 208Pb82+ ion beams at an energy of 6.37 ZTeV. The LHC is equipped with a betatron collimation system, which intercepts the transverse beam halo and protects sensitive equipment such as superconducting magnets against beam losses. However, hadronic fragmentation and electromagnetic dissociation of heavy ions in collimators generate off-rigidity particles, which can be lost in the downstream dispersion suppressor, putting the magnets at risk to quench. An accurate modelling of the beam-induced energy deposition in the collimation system and superconducting magnets is important for quantifying possible performance limitations arising from magnet quenches. In this paper, we compare FLUKA shower simulations against beam loss monitor measurements recorded during the 2018 208Pb82+ run. In particular, we investigate fast beam loss events, which lead to recurring beam aborts in 2018 operation. Based on these studies, we assess the ability of the simulation model to reproduce the observed loss patterns in the collimation region and dispersion suppressor.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST019  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 23 June 2022
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WEPOST042 Radiation Diagnostics for AWA and FACET-II Flat Beams in Plasma plasma, radiation, electron, emittance 1791
 
  • M. Yadav, O. Apsimon, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • H.S. Ancelin, G. Andonian, P. Manwani, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
 
  Funding: This work was performed with support of the US Department of Energy, Division of High Energy Physics, under Contract No. DE-SC0009914, DE-SC0017648 - AWA and STFC grant ST/P006752/1 ,
In energy beam facilities like FACET and AWA, beams with highly asymmetric emittance are of interest because they are the preferred type of beam for linear colliders. That is ultimately the motivation: building a plasma based LC. In this case, the blowout region is no longer symmetric around an axis is not equal in the two transverse planes. Focusing is required to keep the particles within the tight apertures and characterizing these accelerators shows the benefits of employing ultra low beam emittances. Beams with high charge and high emittance ratios in excess of 100:1 are available at AWA. If the focusing will not be equal, then we will have different radiation signatures for the flat and symmetric beams in plasma. We use OSIRIS particle-in-cell codes to compare various scenarios including a weak blowout and a strong blowout. Further, we determine the radiation generated in the system by importing particle trajectories into a Liénard Weichert code. We discuss future steps towards full diagnostics of flat beams using radiation.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST042  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 20 June 2022 — Issue date ※ 05 July 2022
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WEPOPT005 Investigation of Polarized Proton Spin Coherence Time at Storage Rings sextupole, proton, experiment, storage-ring 1832
 
  • A.A. Melnikov, A.E. Aksentyev, Y. Senichev
    RAS/INR, Moscow, Russia
  • A.E. Aksentyev
    MEPhI, Moscow, Russia
  • E. Syresin
    JINR/VBLHEP, Dubna, Moscow region, Russia
 
  Funding: We appreciate a support of this study by the Russian Science Foundation grant 22-42-04419 and the ERC Advanced Grant of the European Union (proposal number 694340).
The idea of the Electric Dipole Moment (EDM) search using the storage ring with polarized beam demands long Spin Coherence Time (SCT). It is the time during which the RMS spread of the orientation of spins of all particles in the bunch reaches one radian. Long SCT is needed to observe a coherent effect on polarization induced by the EDM. The possibility of getting a 1000 s SCT for deuterons has been shown experimentally at COoler SYnchrotron (COSY), accelerator at FZJ Jülich, Germany. Reaching high values of SCT for protons is more challenging due to a higher anomalous magnetic moment. Obtaining sufficient proton SCT is obligatory for planned EDM search experiments at COSY and the ProtoType EDM Ring (PTR). It has been shown that the second order momentum compaction factor (alpha1) has to be optimized along with chromaticities to get high SCT. Three families of sextupoles have to be used. The optimal values of chromaticities and alpha1 are discussed. The racetrack option of PTR is investigated.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT005  
About • Received ※ 16 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 02 July 2022
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WEPOMS001 Effect of Betatron Coupling on Transverse Mode-Coupling and Head-Tail Instabilities coupling, impedance, damping, synchrotron 2225
 
  • W. Foosang, A. Gamelin, R. Nagaoka
    SOLEIL, Gif-sur-Yvette, France
 
  In the context of SOLEIL Upgrade, the 4th generation storage ring project of SOLEIL, several methods are pursued to extend the beam lifetime and limit the emittance growth by reducing the Touschek effect and intra-beam scattering. Betatron coupling is one of the potential techniques to achieve this objective as it can increase the beam volume by transforming a flat beam into a round beam. However, the effect of the coupling on the collective effects is not fully comprehended, but some studies have shown an improvement in transverse instability thresholds. It was, therefore, crucial to investigate the impact of coupling on beam instability for SOLEIL Upgrade. This work presents numerical studies on the impact of coupling on the transverse mode-coupling and the head-tail instabilities. The results showed that coupling could be not only beneficial, but also detrimental.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS001  
About • Received ※ 08 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 04 July 2022  
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WEPOMS019 Beam-Beam Resonance Widths in the HL-LHC, and Reduction by Phasing of Interaction Points resonance, interaction-region, lattice, luminosity 2280
 
  • Y.L. Gao, S.R. Koscielniak
    TRIUMF, Vancouver, Canada
 
  Beam-beam interactions are a limiting factor in the planned high luminosity (HL) upgrade to the Large Hadron Collider (HL-LHC). Over the two main interaction regions of the LHC, a particle experiences two head-on and over a hundred long-range beam-beam interactions which drive betatron resonances in the system. Each resonance line in the space of horizontal and vertical tunes has a finite (non-zero) lock-on width. If the particles tunes fall within this width, they will eventually lock on to the resonance and be driven to large amplitude. We show that it is possible to reduce the resonances widths of a given order by using specific values of the phase advance between interaction points. This paper presents the derivation of resonance width for the weak-strong beam-beam effect, as an extension of A.Chaos width formulae for magnetic sextupoles. (A Lie-algebraic approach is used to combine the effect of the individual beam-beam impulses.) The paper then studies the lock-on width arising from two interaction regions containing 140 beam-beam impulses, and shows the cancellation of specific resonances by relative phasing of interaction points in the HL-LHC lattice.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS019  
About • Received ※ 27 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 22 June 2022
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WEPOMS035 Harpy: A Fast, Simple and Accurate Harmonic Analysis with Error Propagation optics, synchrotron, operation, coupling 2326
 
  • L. Malina
    DESY, Hamburg, Germany
 
  Traditionally, in the accelerator physics field, accurate harmonic analysis has been performed by iteratively interpolating the result of Fast Fourier Transform (FFT) in the frequency domain. Such an approach becomes computationally demanding when relatively small effects are being studied, which is especially evident in the typical example of harmonic analysis of turn-by-turn beam position monitor data, i.e. many correlated but noisy signals. A new harmonic analysis algorithm, called Harpy, is about an order of magnitude faster than other methods, while often being also more accurate. Harpy combines standard techniques such as zero-padded FFT and noise-cleaning based on singular value decomposition. This combination also allows estimating errors of phases and amplitudes of beam-related harmonics calculated from cleaned data.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS035  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 20 June 2022
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THPOMS019 Slow Extraction Modelling for NIMMS Hadron Therapy Synchrotrons extraction, emittance, synchrotron, resonance 2988
 
  • R.L. Taylor
    CERN, Meyrin, Switzerland
  • E. Benedetto, M. Sapinski
    SEEIIST, Geneva, Switzerland
  • J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  Funding: This study was (partially) supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 101008548 (HITRIplus).
The Next Ion Medical Machine Study (NIMMS) is an umbrella R&D programme for CERN accelerator technologies targeting advanced accelerator options for proton and light ion therapy. In collaboration with the European program HITRIplus, one area of study is slow extraction which is required to deliver a uniform beam spill for radiotherapy treatment. Several techniques use the third-order resonance to extract hadrons; these include betatron core driven extraction and radiofrequency knock-out. Flexible simulations tools using these techniques were prepared and initially benchmarked with results from the literature that used the Proton-Ion Medical Machine Study (PIMMS) design. The limits of the current PIMMS design were then pushed to evaluate its compatibility to deliver >10x higher intensity ion beams, and using increased extraction rates.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS019  
About • Received ※ 19 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 21 June 2022
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