arXiv: Accelerator Physics最新文献_第5页

Thermal loading on crystals in an x-ray free-electron laser oscillator x射线自由电子激光振荡器中晶体的热载荷

arXiv: Accelerator Physics Pub Date : 2020-04-15 DOI: 10.1103/PHYSREVACCELBEAMS.23.090704

Nanshun Huang, H. Deng

{"title":"Thermal loading on crystals in an x-ray free-electron laser oscillator","authors":"Nanshun Huang, H. Deng","doi":"10.1103/PHYSREVACCELBEAMS.23.090704","DOIUrl":"https://doi.org/10.1103/PHYSREVACCELBEAMS.23.090704","url":null,"abstract":"X-ray free electron laser oscillators (XFELO) is future light source to produce fully coherent hard X-ray pulses. The X-rays circulate in an optical cavity built from multiple Bragg reflecting mirrors, which has a high reflectance in a bandwidth of ten meV level. The X-ray crystal mirrors exposed to intense X-ray beams in the cavity are subjects to thermal deformations that shift and distort the Bragg reflection. Therefore, the stability of the XFELO operation relies on the abilities of mirrors to preserve the Bragg reflection under such heat load. A new approach was used to analyze the heat load of mirrors and the XFELO operation. The essential light-matter interaction is simulated by the GEANT4 with a dedicated Bragg-reflection physical process to obtain the precise absorption information of the XFELO pulse in the crystals. The transient thermal conduction is analyzed by the finite-element analysis software upon the energy absorption information extract from GEANT4 simulation. A simplified heat-load model is then developed to integrate the heat load in the XFELO. With the help of the heat-load model, the analysis of XFELO operating with several cryogenically cooled diamond mirrors is conducted. The results indicate that the heat load would induce an oscillation when XFELO operates without enough cooling.","PeriodicalId":8436,"journal":{"name":"arXiv: Accelerator Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86466562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Relativistic particle incoherent scattering in oriented crystals 取向晶体中的相对论性粒子非相干散射

arXiv: Accelerator Physics Pub Date : 2020-04-13 DOI: 10.1103/PhysRevAccelBeams.22.054501; 10.1103/PhysRevAccelBeams.23.039901

V. Tikhomirov

{"title":"Relativistic particle incoherent scattering in oriented crystals","authors":"V. Tikhomirov","doi":"10.1103/PhysRevAccelBeams.22.054501; 10.1103/PhysRevAccelBeams.23.039901","DOIUrl":"https://doi.org/10.1103/PhysRevAccelBeams.22.054501; 10.1103/PhysRevAccelBeams.23.039901","url":null,"abstract":"The coherent process of particle deflection by aligned atomic strings and planes of oriented crystals is accompanied by incoherent scattering by atomic cores. While the coherent particle deflection, described by the axial or planar averaged potential, becomes more and more classical at high energies, the incoherent scattering of relativistic particles remains essentially quantum. Though the latter reminds the scattering by atoms of amorphous medium at high enough momentum transfers, at the smallest ones the incoherent scattering process in crystals experiences some modification by the influence of the inhomogeneity of the atom distribution in the plane, normal to the crystal axis or plane. Considering the axial case as a more general example, we present a consistent theory of high energy particles incoherent scattering in oriented crystals. The latter takes into consideration both the quantum scattering nature and the atom distribution inhomogeneity, revealing the limited applicability of the scattering cross section notion. The way to incorporate the quantum scattering features into the widely used classical trajectory simulations is elaborated using newly introduced mean square scattering angle definition.","PeriodicalId":8436,"journal":{"name":"arXiv: Accelerator Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88861385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Channeling of ultrarelativistic particles in a diamond crystal 金刚石晶体中超相对论性粒子的通道

arXiv: Accelerator Physics Pub Date : 2020-04-12 DOI: 10.18721/JPM.11213

K. B. Agapiev, V. Ivanov, A. Korol, A. Solov'yov

引用次数: 1

Online multi-objective particle accelerator optimization of the AWAKE electron beam line for simultaneous emittance and orbit control AWAKE电子束线同步发射和轨道控制的在线多目标粒子加速器优化

arXiv: Accelerator Physics Pub Date : 2020-03-24 DOI: 10.1063/5.0003423

A. Scheinker, Simon Hirlaender, F. Velotti, S. Gessner, G. D. Della Porta, V. Kain, B. Goddard, R. Ramjiawan

引用次数: 19

Study of collective effects in the CERN FCC-ee top-up booster 欧洲核子研究中心FCC-ee充值助推器的集体效应研究

arXiv: Accelerator Physics Pub Date : 2020-03-22 DOI: 10.23732/CYRCP-2020-009.362

D. Quartullo, M. Migliorati, M. Zobov

引用次数: 0

Modern and future colliders 现代和未来的对撞机

arXiv: Accelerator Physics Pub Date : 2020-03-20 DOI: 10.1103/REVMODPHYS.93.015006

V. Shiltsev, F. Zimmermann

引用次数: 80

Resonant excitation of very high gradient plasma wakefield accelerators by optical-period bunch trains 高梯度等离子体尾流场加速器的光周期束列共振激发

arXiv: Accelerator Physics Pub Date : 2020-03-19 DOI: 10.1103/PhysRevAccelBeams.24.051302

Pratik Manwani, N. Majernik, J. Rosenzweig

引用次数: 8

Toward the Frontiers of Particle Physics with the Muon g-2 Experiment 用μ子g-2实验走向粒子物理学的前沿

arXiv: Accelerator Physics Pub Date : 2020-03-15 DOI: 10.2172/1623356

E. Valetov

{"title":"Toward the Frontiers of Particle Physics with the Muon g-2 Experiment","authors":"E. Valetov","doi":"10.2172/1623356","DOIUrl":"https://doi.org/10.2172/1623356","url":null,"abstract":"The Muon $gtextrm{-}2$ Experiment (E989) at Fermilab has a goal of measuring the muon anomaly ($a_mu$) with unprecedented precision using positive muons. This measurement is motivated by the difference between the previous Brookhaven $a_mu$ measurement and Standard Model prediction exceeding three standard deviations, which hints at the possibility of physics beyond the Standard Model. Muons are circulated in a storage ring, and the measurement requires a precise determination of the muon anomalous precession frequency (spin precession relative to momentum) from the resulting decay positron time and energy measurements collected with calorimeters. The average magnetic field seen by the muons needs to be known with high precision, and so the storage ring magnetic field is shimmed to be very uniform and is continually monitored with nuclear magnetic resonance (NMR) probes. Detailed Muon Campus beamline and muon storage ring simulations are also required for quantifying beam dynamics and spin-related systematic effects in the determination of the muon anomalous precession frequency, e.g. muon losses during the measurement window. At the time of the conference, the experiment has recently commenced Run-3, and the release of Run-1 physics results is planned for 2020.","PeriodicalId":8436,"journal":{"name":"arXiv: Accelerator Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87780886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of the 50 Hz harmonics on the beam evolution of the Large Hadron Collider 50 Hz谐波对大型强子对撞机束流演化的影响

arXiv: Accelerator Physics Pub Date : 2020-02-29 DOI: 10.1103/PHYSREVACCELBEAMS.24.034002

S. Kostoglou, G. Arduini, Y. Papaphilippou, G. Sterbini, L. Intelisano

{"title":"Impact of the 50 Hz harmonics on the beam evolution of the Large Hadron Collider","authors":"S. Kostoglou, G. Arduini, Y. Papaphilippou, G. Sterbini, L. Intelisano","doi":"10.1103/PHYSREVACCELBEAMS.24.034002","DOIUrl":"https://doi.org/10.1103/PHYSREVACCELBEAMS.24.034002","url":null,"abstract":"Harmonics of the mains frequency (50 Hz) have been systematically observed in the transverse beam spectrum of the Large Hadron Collider (LHC) since the start of its operation in the form of dipolar excitations. In the presence of strong non-linearities such as beam-beam interactions, as many of these power supply ripple tones reside in the vicinity of the betatron tune they can increase the tune diffusion of the particles in the distribution, leading to proton losses and eventually to a significant reduction of the beam lifetime. The aim of this paper is to determine whether the 50~Hz harmonics have an impact on the beam performance of the LHC. A quantitative characterization of the ripple spectrum present in the operation of the accelerator, together with an understanding of its source is an essential ingredient to also evaluate the impact of the 50~Hz harmonics on the future upgrade of the LHC, the High Luminosity LHC (HL-LHC). To this end, simulations with the single-particle tracking code, SixTrack, are employed including a realistic ripple spectrum as extracted from experimental observations to quantify the impact of such effects in terms of tune diffusion, Dynamic Aperture and beam lifetime. The methods and results of the tracking studies are reported and discussed in this paper.","PeriodicalId":8436,"journal":{"name":"arXiv: Accelerator Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86471540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Origin of the 50 Hz harmonics in the transverse beam spectrum of the Large Hadron Collider 大型强子对撞机横束谱中50 Hz谐波的起源

arXiv: Accelerator Physics Pub Date : 2020-02-29 DOI: 10.1103/PHYSREVACCELBEAMS.24.034001

S. Kostoglou, G. Arduini, Y. Papaphilippou, G. Sterbini, L. Intelisano

引用次数: 1