Physical Review Special Topics-accelerators and Beams最新文献_第2页

Beam-dynamics driven design of the LHeC energy-recovery linac 束流动力学驱动的LHeC能量回收直线装置设计

Physical Review Special Topics-accelerators and Beams Pub Date : 2015-12-23 DOI: 10.1103/PHYSREVSTAB.18.121004

D. Pellegrini, A. Latina, D. Schulte, S. Bogacz

{"title":"Beam-dynamics driven design of the LHeC energy-recovery linac","authors":"D. Pellegrini, A. Latina, D. Schulte, S. Bogacz","doi":"10.1103/PHYSREVSTAB.18.121004","DOIUrl":"https://doi.org/10.1103/PHYSREVSTAB.18.121004","url":null,"abstract":"The LHeC is envisioned as a natural upgrade of the LHC that aims at delivering an electron beam for collisions with the existing hadronic beams. The current baseline design for the electron facility consists of a multipass superconducting energy-recovery linac (ERL) operating in a continuous wave mode. The unprecedently high energy of the multipass ERL combined with a stringent emittance dilution budget poses new challenges for the beam optics. Here, we investigate the performances of a novel arc architecture based on a flexible momentum compaction lattice that mitigates the effects of synchrotron radiation while containing the bunch lengthening. Extensive beam-dynamics investigations have been performed with PLACET2, a recently developed tracking code for recirculating machines. They include the first end-to-end tracking and a simulation of the machine operation with a continuous beam. This paper briefly describes the Conceptual Design Report lattice, with an emphasis on possible and proposed improvements that emerged from the beam-dynamics studies. The detector bypass section has been integrated in the lattice, and its design choices are presented here. The stable operation of the ERL with a current up to similar to 150 mA in the linacs has been validated in the presence of single- and multibunch wakefields, synchrotron radiation, and beam-beam effects.","PeriodicalId":20072,"journal":{"name":"Physical Review Special Topics-accelerators and Beams","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82373285","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: 13

Low emittance injector design for free electron lasers 自由电子激光器的低发射度注入器设计

Physical Review Special Topics-accelerators and Beams Pub Date : 2015-12-21 DOI: 10.1103/PHYSREVSTAB.18.123403

S. Bettoni, M. Pedrozzi, S. Reiche

引用次数: 16

Maximal charge injection of a uniform separated electron pulse train in a drift space 漂移空间中均匀分离电子脉冲序列的最大电荷注入

Physical Review Special Topics-accelerators and Beams Pub Date : 2015-12-21 DOI: 10.1103/PHYSREVSTAB.18.123402

Y. Liu, Peng Zhang, Shih-Hung Chen, L. Ang

引用次数: 4

Characterization of pseudosingle bunch kick-and-cancel operational mode 伪单束踢消工作模式的表征

Physical Review Special Topics-accelerators and Beams Pub Date : 2015-12-18 DOI: 10.1103/PHYSREVSTAB.18.120702

Changchun Sun, D. Robin, C. Steier, G. Portmann

{"title":"Characterization of pseudosingle bunch kick-and-cancel operational mode","authors":"Changchun Sun, D. Robin, C. Steier, G. Portmann","doi":"10.1103/PHYSREVSTAB.18.120702","DOIUrl":"https://doi.org/10.1103/PHYSREVSTAB.18.120702","url":null,"abstract":"Author(s): Sun, C; Robin, DS; Steier, C; Portmann, G | Abstract: © 2015 authors. Published by the American Physical Society. Pseudosingle-bunch kick-and-cancel (PSB-KAC) is a new operational mode at the Advanced Light Source of Lawrence Berkeley National Laboratory that provides full timing and repetition rate control for single x-ray pulse users while being fully transparent to other users of synchrotron radiation light. In this operational mode, a single electron bunch is periodically displaced from a main bunch train by a fast kicker magnet with a user-on-demand repetition rate, creating a single x-ray pulse to be matched to a typical laser excitation pulse rate. This operational mode can significantly improve the signal to noise ratio of single x-ray pulse experiments and drastically reduce dose-induced sample damage rate. It greatly expands the capabilities of synchrotron light sources to carry out dynamics and time-of-flight experiments. In this paper, we carry out extensive characterizations of this PSB-KAC mode both numerically and experimentally. This includes the working principle of this mode, resonance conditions and beam stability, experimental setups, and diagnostic tools and measurements.","PeriodicalId":20072,"journal":{"name":"Physical Review Special Topics-accelerators and Beams","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87573301","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: 7

Effects of processing history on the evolution of surface damage layer and dislocation substructure in large grain niobium cavities 加工历史对大晶粒铌空腔表面损伤层和位错亚结构演变的影响

Physical Review Special Topics-accelerators and Beams Pub Date : 2015-12-16 DOI: 10.1103/PHYSREVSTAB.18.123501

D. Kang, T. Bieler, C. Compton

{"title":"Effects of processing history on the evolution of surface damage layer and dislocation substructure in large grain niobium cavities","authors":"D. Kang, T. Bieler, C. Compton","doi":"10.1103/PHYSREVSTAB.18.123501","DOIUrl":"https://doi.org/10.1103/PHYSREVSTAB.18.123501","url":null,"abstract":"Large grain niobium (Nb) is being investigated for fabricating superconducting radiofrequency cavities as an alternative to the traditional approach using fine grain polycrystalline Nb sheets. Past studies have identified a surface damage layer on fine grain cavities due to deep drawing and demonstrated the necessity for chemical etching on the surface. However, the origin of and depth of the damage layer are not well understood, and similar exploration on large grain cavities is lacking. In this work, electron backscatter diffraction (EBSD) was used to examine the cross sections at the equator and iris of a half cell deep drawn from a large grain Nb ingot slice. The results indicate that the damage (identified by a high density of geometrically necessary dislocations) depends on crystal orientations, is different at the equator and iris, and is present through the full thickness of a half cell in some places. After electron backscatter diffraction, the specimens were heat treated at 800 °C or 1000 °C for two hours, and the same areas were reexamined. A more dramatic decrease in dislocation content was observed at the iris than the equator, where some regions exhibited no change. The specimens were then etched and examined again, tomore » determine if the subsurface region behaved differently than the surface. As a result, little change in the dislocation substructure was observed, suggesting that the large grain microstructure is retained with a normal furnace anneal.« less","PeriodicalId":20072,"journal":{"name":"Physical Review Special Topics-accelerators and Beams","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74068856","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: 3

Fundamental beam-beam limit from head-on interaction in the Large Hadron Collider 大型强子对撞机中迎面相互作用的基本束束极限

Physical Review Special Topics-accelerators and Beams Pub Date : 2015-12-15 DOI: 10.1103/PHYSREVSTAB.18.121003

K. Ohmi, F. Zimmermann

引用次数: 8

Synchronization of radiation in an oversized coaxial Ka-band backward wave oscillator using two-dimensional Bragg structure 利用二维布拉格结构的超大同轴ka波段后向波振荡器辐射同步

Physical Review Special Topics-accelerators and Beams Pub Date : 2015-12-11 DOI: 10.1103/PHYSREVSTAB.18.120701

N. Ginzburg, E. V. Ilyakov, I. Kulagin, N. Peskov, R. Rozental, A. Sergeev, V. Zaslavsky, I. Zheleznov

引用次数: 7

Production of high energy-solid density electron bunches and hard γ -quanta and positron fluxes by ultrarelativistic lasers in solid-plasma targets 用超相对论性激光在固体等离子体靶中产生高能固体密度电子束和硬γ量子和正电子通量

Physical Review Special Topics-accelerators and Beams Pub Date : 2015-12-11 DOI: 10.1103/PHYSREVSTAB.18.121301

H. Avetissian, H. H. Matevosyan, G. F. Mkrtchian, Kh. V. Sedrakian

引用次数: 3

Method of phase space beam dilution utilizing bounded chaos generated by rf phase modulation 利用射频相位调制产生有界混沌的相空间波束稀释方法

Physical Review Special Topics-accelerators and Beams Pub Date : 2015-12-10 DOI: 10.1103/PHYSREVSTAB.18.124001

A. Pham, S. Lee, K. Ng

引用次数: 6

Systematic studies on the effect of linear lattice optics for space-charge limited beams 线性点阵光学对空间电荷限制光束影响的系统研究

Physical Review Special Topics-accelerators and Beams Pub Date : 2015-12-08 DOI: 10.1103/PHYSREVSTAB.18.124201

M. Fitterer, C. Carli, A. Molodozhentsev, A. Müller

引用次数: 1