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Preview: Recent Articles in Phys. Rev. ST Accel. Beams

Recent Articles in Phys. Rev. Accel. Beams

Recent articles in Physical Review Accelerators and Beams

Published: 2017-12-11T21:02:46+00:00


Realistic simulations of a cyclotron spiral inflector within a particle-in-cell framework


Author(s): Daniel Winklehner, Andreas Adelmann, Achim Gsell, Tulin Kaman, and Daniela Campo

We present an upgrade to the particle-in-cell ion beam simulation code opal that enables us to run highly realistic simulations of the spiral inflector system of a compact cyclotron. This upgrade includes a new geometry class and field solver that can handle the complicated boundary conditions posed...

[Phys. Rev. Accel. Beams 20, 124201] Published Mon Dec 11, 2017

Evolution of a beam dynamics model for the transport line in a proton therapy facility


Author(s): V. Rizzoglio, A. Adelmann, C. Baumgarten, M. Frey, A. Gerbershagen, D. Meer, and J. M. Schippers

During the conceptual design of an accelerator or beamline, first-order beam dynamics models are essential for studying beam properties. However, they can only produce approximate results. During commissioning, these approximate results are compared to measurements, which will rarely coincide if the...

[Phys. Rev. Accel. Beams 20, 124702] Published Mon Dec 11, 2017

Computer codes for beam dynamics analysis of cyclotronlike accelerators


Author(s): V. Smirnov

Computer codes suitable for the study of beam dynamics in cyclotronlike (classical and isochronous cyclotrons, synchrocyclotrons, and fixed field alternating gradient) accelerators are reviewed. Computer modeling of cyclotron segments, such as the central zone, acceleration region, and extraction sy...

[Phys. Rev. Accel. Beams 20, 124801] Published Mon Dec 11, 2017

Development of a radio-frequency quadrupole cooler for high beam currents


Author(s): Ramzi Boussaid, G. Ban, G. Quéméner, Y. Merrer, and J. Lorry

The SHIRaC prototype is a recently developed radio-frequency quadrupole (RFQ) beam cooler with an improved optics design to deliver the required beam quality to a high resolution separator (HRS). For an isobaric separation of isotopes, the HRS demands beams with emittance not exceeding $3π\text{ }\t...

[Phys. Rev. Accel. Beams 20, 124701] Published Wed Dec 06, 2017

Gain cascading scheme of a free-electron-laser oscillator


Author(s): Kai Li and Haixiao Deng

The low-gain free-electron laser (FEL) oscillators are cutting-edge tools to produce fully coherent radiation in the spectral region from terahertz to vacuum ultraviolet, and potentially in hard x ray. In this paper, it is proposed to utilize an FEL oscillator with multistage undulators to enable ga...

[Phys. Rev. Accel. Beams 20, 110703] Published Thu Nov 30, 2017

Threshold of transverse mode coupling instability with arbitrary space charge


Author(s): V. Balbekov

The threshold of the transverse mode coupling instability is calculated in framework of the square well model at arbitrary value of space charge tune shift. A new method of calculation is developed beyond the traditional expansion technique. The square, resistive, and exponential wakes are investiga...

[Phys. Rev. Accel. Beams 20, 114401] Published Thu Nov 30, 2017

Upgrade possibilities for continuous wave rf electron guns based on room-temperature very high frequency technology


Author(s): F. Sannibale, D. Filippetto, M. Johnson, D. Li, T. Luo, C. Mitchell, J. Staples, S. Virostek, R. Wells, and J. M. Byrd

The past decade was characterized by an increasing scientific demand for extending towards higher repetition rates (MHz class and beyond) the performance of already operating lower repetition rate accelerator-based instruments such as x-ray free electron lasers (FELs) and ultrafast electron diffract...

[Phys. Rev. Accel. Beams 20, 113402] Published Mon Nov 27, 2017

Local correction of quadrupole errors at LHC interaction regions using action and phase jump analysis on turn-by-turn beam position data


Author(s): Javier Fernando Cardona, Alba Carolina García Bonilla, and Rogelio Tomás García

This article shows that the effect of all quadrupole errors present in an interaction region with low $β*$ can be modeled by an equivalent magnetic kick, which can be estimated from action and phase jumps found on beam position data. This equivalent kick is used to find the strengths that certain no...

[Phys. Rev. Accel. Beams 20, 111004] Published Wed Nov 22, 2017

Unavoidable trapped mode in the interaction region of colliding beams


Author(s): Alexander Novokhatski, Michael Sullivan, Eleonora Belli, Miguel Gil Costa, and Roberto Kersevan

We discuss the nature of the electromagnetic fields excited by the beams in the beam pipe of an interaction region. In trying to find an optimum geometry for this region with a minimum of electromagnetic wave excitation, we have discovered one mode, which remains even in a very smooth geometry. This...

[Phys. Rev. Accel. Beams 20, 111005] Published Wed Nov 22, 2017

Characterizing temporal coherence of visible synchrotron radiation with heterodyne near field speckles


Author(s): M. Siano, B. Paroli, M. A. C. Potenza, U. Iriso, A. A. Nosych, L. Torino, S. Mazzoni, G. Trad, and A. N. Goldblatt

In this paper we extensively describe the heterodyne near field speckle method (HNFS) to characterize both spatial and temporal coherence of synchrotron radiation (SR). The method relies on Fourier analysis of near field speckles generated by scattering from nanoparticles suspended in a liquid. A cr...

[Phys. Rev. Accel. Beams 20, 110702] Published Tue Nov 21, 2017

Accelerator performance analysis of the Fermilab Muon Campus


Author(s): Diktys Stratakis, Mary E. Convery, Carol Johnstone, John Johnstone, James P. Morgan, Dean Still, Jason D. Crnkovic, Vladimir Tishchenko, William M. Morse, and Michael J. Syphers

Fermilab is dedicated to hosting world-class experiments in search of new physics that will operate in the coming years. The Muon g-2 Experiment is one such experiment that will determine with unprecedented precision the muon anomalous magnetic moment, which offers an important test of the Standard ...

[Phys. Rev. Accel. Beams 20, 111003] Published Tue Nov 21, 2017

High quality electron bunch generation using a longitudinal density-tailored plasma-based accelerator in the three-dimensional blowout regime


Author(s): X. L. Xu, F. Li, W. An, T. N. Dalichaouch, P. Yu, W. Lu, C. Joshi, and W. B. Mori

Plasma-based acceleration in density down ramps is proposed to generate electron beams with unprecedented combinations of brightness and energy spread, which can drive a new class of compact free-electron-lasers and linear colliders.

[Phys. Rev. Accel. Beams 20, 111303] Published Tue Nov 21, 2017

Transparent lattice characterization with gated turn-by-turn data of diagnostic bunch train


Author(s): Yongjun Li, Weixing Cheng, Kiman Ha, and Robert Rainer

Methods of characterization of a storage ring’s lattice have traditionally been intrusive to routine operations. More importantly, the lattice seen by particles can drift with the beam current due to collective effects. To circumvent this, we have developed a novel approach for dynamically character...

[Phys. Rev. Accel. Beams 20, 112802] Published Tue Nov 21, 2017

First accelerator test of vacuum components with laser-engineered surfaces for electron-cloud mitigation


Author(s): Sergio Calatroni, Elisa Garcia-Tabares Valdivieso, Holger Neupert, Valentin Nistor, Ana Teresa Perez Fontenla, Mauro Taborelli, Paolo Chiggiato, Oleg Malyshev, Reza Valizadeh, Stefan Wackerow, Svetlana A. Zolotovskaya, W. Allan Gillespie, and Amin Abdolvand

Laser treatment of an accelerator vacuum chamber is shown to be an efficient and robust measure against electron-cloud formation.

[Phys. Rev. Accel. Beams 20, 113201] Published Mon Nov 20, 2017

High efficiency tapered free-electron lasers with a prebunched electron beam


Author(s): C. Emma, N. Sudar, P. Musumeci, A. Urbanowicz, and C. Pellegrini

In this paper we analyze the high gain, high efficiency tapered free-electron laser amplifier with a prebunched electron beam. Simple scaling laws are derived for the peak output power and extraction efficiency and verified using 1D simulations. These studies provide useful analytical expressions wh...

[Phys. Rev. Accel. Beams 20, 110701] Published Fri Nov 17, 2017

Publisher’s Note: Model-based optimization of tapered free-electron lasers [Phys. Rev. ST Accel. Beams 18, 040702 (2015)]


Author(s): Alan Mak, Francesca Curbis, and Sverker Werin
[Phys. Rev. Accel. Beams 20, 119902] Published Fri Nov 17, 2017

Publisher’s Note: Phase jump method for efficiency enhancement in free-electron lasers [Phys. Rev. Accel. Beams 20, 060703 (2017)]


Author(s): Alan Mak, Francesca Curbis, and Sverker Werin
[Phys. Rev. Accel. Beams 20, 119901] Published Tue Nov 14, 2017

Analytical $N$ beam position monitor method


Author(s): A. Wegscheider, A. Langner, R. Tomás, and A. Franchi

Measurement and correction of focusing errors is of great importance for performance and machine protection of circular accelerators. Furthermore LHC needs to provide equal luminosities to the experiments ATLAS and CMS. High demands are also set on the speed of the optics commissioning, as the fores...

[Phys. Rev. Accel. Beams 20, 111002] Published Fri Nov 10, 2017

Development for a supercompact $X$-band pulse compression system and its application at SLAC


Author(s): Juwen W. Wang, Sami G. Tantawi, Chen Xu, Matt Franzi, Patrick Krejcik, Gordon Bowden, Shantha Condamoor, Yuantao Ding, Valery Dolgashev, John Eichner, Andrew Haase, James R. Lewandowski, and Liling Xiao

We have successfully designed, fabricated, installed, and tested a super compact $X$-band SLAC Energy Doubler system at SLAC. It is composed of an elegant 3 dB coupler–mode converter–polarizer coupled to a single spherical energy storage cavity with high ${Q}_{0}$ of 94000 and a diameter less than 1...

[Phys. Rev. Accel. Beams 20, 110401] Published Thu Nov 09, 2017

Temperature-dependent quantum efficiency degradation of K-Cs-Sb bialkali antimonide photocathodes grown by a triple-element codeposition method


Author(s): Zihao Ding, Siddharth Karkare, Jun Feng, Daniele Filippetto, Matthew Johnson, Steve Virostek, Fernando Sannibale, James Nasiatka, Mengjia Gaowei, John Sinsheimer, Erik Muller, John Smedley, and Howard Padmore

K-Cs-Sb bialkali antimonide photocathodes grown by a triple-element codeposition method have been found to have excellent quantum efficiency (QE) and outstanding near-atomic surface smoothness and have been employed in the VHF gun in the Advanced Photoinjector Experiment (APEX), however, their robus...

[Phys. Rev. Accel. Beams 20, 113401] Published Thu Nov 09, 2017

Low energy tertiary beam line design for the CERN neutrino platform project


Author(s): N. Charitonidis and I. Efthymiopoulos

In the framework of CERN neutrino platform project at the CERN SPS North Area, two new beam lines have been designed as extensions of the existing secondary beam lines, able to provide low energy particles in the momentum range of 0.4 to $12\text{ }\text{ }\mathrm{GeV}/c$. The layout of these very l...

[Phys. Rev. Accel. Beams 20, 111001] Published Tue Nov 07, 2017

Beam dynamics analysis of dielectric laser acceleration using a fast 6D tracking scheme


Author(s): Uwe Niedermayer, Thilo Egenolf, and Oliver Boine-Frankenheim

An important step toward high fidelity beam-transport codes for dielectric laser accelerators is presented with the long-term goal of building an entire microchip-sized laser-driven accelerator.

[Phys. Rev. Accel. Beams 20, 111302] Published Fri Nov 03, 2017

rf design of a pulse compressor with correction cavity chain for klystron-based compact linear collider


Author(s): Ping Wang, Hao Zha, Igor Syratchev, Jiaru Shi, and Huaibi Chen

We present an X-band high-power pulse compression system for a klystron-based compact linear collider. In this system design, one rf power unit comprises two klystrons, a correction cavity chain, and two SLAC Energy Doubler (SLED)-type X-band pulse compressors (SLEDX). An rf pulse passes the correct...

[Phys. Rev. Accel. Beams 20, 112001] Published Fri Nov 03, 2017

Temporal profile monitor based on electro-optic spatial decoding for low-energy bunches


Author(s): Wei Wang, Yingchao Du, Lixin Yan, Zhijun Chi, Zhen Zhang, Jianfei Hua, Wenhui Huang, Chuanxiang Tang, and Ming Li

The measurement of electron bunch temporal profile is one of the key diagnostics in accelerators, especially for ultrashort bunches. The electro-optic (EO) technique enables the precise longitudinal characterization of bunch electric field in a single-shot and nondestructive way, which can simultane...

[Phys. Rev. Accel. Beams 20, 112801] Published Fri Nov 03, 2017

Emittance preservation in plasma-based accelerators with ion motion


Author(s): C. Benedetti, C. B. Schroeder, E. Esarey, and W. P. Leemans

In a plasma-accelerator-based linear collider, the density of matched, low-emittance, high-energy particle bunches required for collider applications can be orders of magnitude above the background ion density, leading to ion motion, perturbation of the focusing fields, and, hence, to beam emittance...

[Phys. Rev. Accel. Beams 20, 111301] Published Wed Nov 01, 2017

Magnesium diboride on inner wall of copper tube: A test case for superconducting radio frequency cavities


Author(s): Wenura K. Withanage, N. H. Lee, Sashank V. Penmatsa, M. A. Wolak, A. Nassiri, and X. X. Xi

Superconductor magnesium diboride is considered one of the viable materials to substitute bulk niobium for superconducting radio frequency cavities. Utilizing a ${\mathrm{MgB}}_{2}$ coating on the inner wall of a copper cavity will allow operation at higher temperatures (20–25 K) than Nb cavities du...

[Phys. Rev. Accel. Beams 20, 102002] Published Tue Oct 31, 2017

High-quality electron beam generation in a proton-driven hollow plasma wakefield accelerator


Author(s): Y. Li, G. Xia, K. V. Lotov, A. P. Sosedkin, K. Hanahoe, and O. Mete-Apsimon

Simulations of proton-driven plasma wakefield accelerators have demonstrated substantially higher accelerating gradients compared to conventional accelerators and the viability of accelerating electrons to the energy frontier in a single plasma stage. However, due to the strong intrinsic transverse ...

[Phys. Rev. Accel. Beams 20, 101301] Published Thu Oct 26, 2017

Spatial control of photoemitted electron beams using a microlens-array transverse-shaping technique


Author(s): A. Halavanau, G. Qiang, G. Ha, E. Wisniewski, P. Piot, J. G. Power, and W. Gai

A transversely inhomogeneous laser distribution on the photocathode surface generally produces electron beams with degraded beam quality. In this paper, we explore the use of microlens arrays to dramatically improve the transverse uniformity of an ultraviolet drive-laser pulse used in a photoinjecto...

[Phys. Rev. Accel. Beams 20, 103404] Published Thu Oct 26, 2017

Modeling of second order space charge driven coherent sum and difference instabilities


Author(s): Yao-Shuo Yuan, Oliver Boine-Frankenheim, and Ingo Hofmann

Second order coherent oscillation modes in intense particle beams play an important role for beam stability in linear or circular accelerators. In addition to the well-known second order even envelope modes and their instability, coupled even envelope modes and odd (skew) modes have recently been sh...

[Phys. Rev. Accel. Beams 20, 104201] Published Thu Oct 26, 2017

Temperature dependence of alkali-antimonide photocathodes: Evaluation at cryogenic temperatures


Author(s): M. A. Mamun, M. R. Hernandez-Flores, E. Morales, C. Hernandez-Garcia, and M. Poelker

${\mathrm{Cs}}_{x}{\mathrm{K}}_{y}\mathrm{Sb}$ photocathodes were manufactured on a niobium substrate and evaluated over a range of temperatures from 300 to 77 K. Vacuum conditions were identified that minimize surface contamination due to gas adsorption when samples were cooled below room temperatu...

[Phys. Rev. Accel. Beams 20, 103403] Published Tue Oct 24, 2017

Electromagnetic fields and Green’s functions in elliptical vacuum chambers


Author(s): S. Persichelli, N. Biancacci, M. Migliorati, L. Palumbo, and V. G. Vaccaro

In this paper, we discuss the electromagnetic interaction between a point charge travelling inside a waveguide of elliptical cross section, and the waveguide itself. By using a convenient expansion of the Mathieu functions, useful in particular for treating a variety of problems in applied mathemati...

[Phys. Rev. Accel. Beams 20, 101004] Published Mon Oct 23, 2017

Measurements of wake-induced electron beam deflection in a dechirper at the Linac Coherent Light Source


Author(s): Johann Zemella, Karl Bane, Alan Fisher, Marc Guetg, Zhirong Huang, Richard Iverson, Patrick Krejcik, Alberto Lutman, Timothy Maxwell, Alexander Novokhatski, Gennady Stupakov, Zhen Zhang, Mark Harrison, and Marcos Ruelas

The RadiaBeam/SLAC dechirper, a structure consisting of pairs of flat, metallic, corrugated plates, has been installed just upstream of the undulators in the Linac Coherent Light Source (LCLS). As a dechirper, with the beam passing between the plates on axis, longitudinal wakefields are induced that...

[Phys. Rev. Accel. Beams 20, 104403] Published Thu Oct 19, 2017

Aligning linac accelerating structures using a copropagating octupolar mode


Author(s): J. Ögren and V. Ziemann

We propose a novel method to align accelerating structures such as those used in the Compact Linear Collider (CLIC) by exploiting a mode that copropagates with the normal accelerating mode. This mode has an octupolar dependence in the transverse direction and is caused by radial waveguides intended ...

[Phys. Rev. Accel. Beams 20, 102801] Published Mon Oct 16, 2017

Medical therapy and imaging fixed-field alternating-gradient accelerator with realistic magnets


Author(s): S. Tygier, K. B. Marinov, R. B. Appleby, J. A. Clarke, J. M. Garland, H. L. Owen, and B. J. A. Shepherd

NORMA is a design for a normal-conducting racetrack fixed-field alternating-gradient accelerator for protons from 50 to 350 MeV. In this article we show the development from an idealized lattice to a design implemented with field maps from rigorous two-dimensional (2D) and three-dimensional (3D) FEM...

[Phys. Rev. Accel. Beams 20, 104702] Published Mon Oct 16, 2017

Optimal radius of crystal curvature for planar channeling of high-energy negatively charged particles in a bent crystal


Author(s): I. V. Kirillin

The problem of planar channeling of high-energy negatively charged particles in a bent crystal was considered on the basis of analytical calculation and numerical simulation. We show the existence of an optimal radius of crystal curvature for planar channeling, corresponding to the maximum deflectio...

[Phys. Rev. Accel. Beams 20, 104401] Published Fri Oct 13, 2017

Analysis of transverse beam stabilization with radio frequency quadrupoles


Author(s): M. Schenk, A. Grudiev, K. Li, and K. Papke

A radio frequency (rf) quadrupole has been considered as a potential alternative device for Landau damping in circular hadron colliders. The objective of this study is to benchmark and confirm its stabilizing effect predicted by stability diagram theory by means of numerical tracking simulations. To...

[Phys. Rev. Accel. Beams 20, 104402] Published Fri Oct 13, 2017

High current nonlinear transmission line based electron beam driver


Author(s): B. W. Hoff, D. M. French, D. S. Simon, P. D. Lepell, T. Montoya, and S. L. Heidger

A gigawatt-class nonlinear transmission line based electron beam driver is experimentally demonstrated. Four experimental series, each with a different Marx bank charge voltage (15, 20, 25, and 30 kV), were completed. Within each experimental series, shots at peak frequencies ranging from 950 MHz to...

[Phys. Rev. Accel. Beams 20, 100401] Published Thu Oct 12, 2017

Efficient model for low-energy transverse beam dynamics in a nine-cell 1.3 GHz cavity


Author(s): Thorsten Hellert, Martin Dohlus, and Winfried Decking

FLASH and the European XFEL are SASE-FEL user facilities, at which superconducting TESLA cavities are operated in a pulsed mode to accelerate long bunch-trains. Several cavities are powered by one klystron. While the low-level rf system is able to stabilize the vector sum of the accelerating gradien...

[Phys. Rev. Accel. Beams 20, 100702] Published Thu Oct 12, 2017

Cavity voltage phase modulation to reduce the high-luminosity Large Hadron Collider rf power requirements


Author(s): T. Mastoridis, P. Baudrenghien, and J. Molendijk

For uneven bunch filling patterns, adapting the rf voltage reference reduces the klystron power and allows operation at higher beam intensity.

[Phys. Rev. Accel. Beams 20, 101003] Published Tue Oct 10, 2017

3D multiphysics modeling of superconducting cavities with a massively parallel simulation suite


Author(s): Oleksiy Kononenko, Chris Adolphsen, Zenghai Li, Cho-Kuen Ng, and Claudio Rivetta

Radiofrequency cavities based on superconducting technology are widely used in particle accelerators for various applications. The cavities usually have high quality factors and hence narrow bandwidths, so the field stability is sensitive to detuning from the Lorentz force and external loads, includ...

[Phys. Rev. Accel. Beams 20, 102001] Published Tue Oct 10, 2017

Experimental studies of 7-cell dual axis asymmetric cavity for energy recovery linac


Author(s): I. V. Konoplev, K. Metodiev, A. J. Lancaster, G. Burt, R. Ainsworth, and A. Seryi

High average current, transportable energy recovery linacs (ERLs) can be very attractive tools for a number of applications including next generation high-luminosity, compact light sources. Conventional ERLs are based on an electron beam circulating through the same set of rf cavity cells. This lead...

[Phys. Rev. Accel. Beams 20, 103501] Published Tue Oct 10, 2017

Beam-beam amplitude detuning with forced oscillations


Author(s): R. Tomás, X. Buffat, S. White, J. Barranco, P. Gonçalves Jorge, and T. Pieloni

Recently, relations were established between the coefficients of free and forced amplitude detuning polynomial expansions. The forced oscillations were considered only in a single plane. In this paper we extend and generalize previous results by developing analytical equations that transform the fre...

[Phys. Rev. Accel. Beams 20, 101002] Published Mon Oct 09, 2017

Control and performance improvements of a pulse compressor in use for testing accelerating structures at high power


Author(s): Benjamin Woolley, Igor Syratchev, and Amos Dexter

New developments relating to compact X-band, SLED-I type pulse compressors being developed at CERN for testing high gradient structures are described. Pulse compressors of interest take rf pulses from one or more high power klystrons with duration typically $>1.5\text{ }\text{ }μ\mathrm{s}$ and d...

[Phys. Rev. Accel. Beams 20, 101001] Published Thu Oct 05, 2017

Generation of a femtosecond electron microbunch train from a photocathode using twofold Michelson interferometer


Author(s): M. Shevelev, A. Aryshev, N. Terunuma, and J. Urakawa

The interest in producing ultrashort electron bunches has risen sharply among scientists working on the design of high-gradient wakefield accelerators. One attractive approach generating electron bunches is to illuminate a photocathode with a train of femtosecond laser pulses. In this paper we descr...

[Phys. Rev. Accel. Beams 20, 103401] Published Wed Oct 04, 2017

Effect of double frequency heating on the lead afterglow beam currents of an electron cyclotron resonance ion source


Author(s): V. Toivanen, G. Bellodi, D. Küchler, F. Wenander, and O. Tarvainen

The effect of double frequency heating on the performance of the CERN GTS-LHC 14.5 GHz Electron Cyclotron Resonance (ECR) ion source in afterglow mode is reported. The source of the secondary microwave frequency was operated both in pulsed and continuous wave (CW) modes within the range of 12–18 GHz...

[Phys. Rev. Accel. Beams 20, 103402] Published Wed Oct 04, 2017

Development and operating experience of a 1.1-m-long superconducting undulator at the Advanced Photon Source


Author(s): Y. Ivanyushenkov, K. Harkay, M. Borland, R. Dejus, J. Dooling, C. Doose, L. Emery, J. Fuerst, J. Gagliano, Q. Hasse, M. Kasa, P. Kenesei, V. Sajaev, K. Schroeder, N. Sereno, S. Shastri, Y. Shiroyanagi, D. Skiadopoulos, M. Smith, X. Sun, E. Trakhtenberg, A. Xiao, A. Zholents, and E. Gluskin

Development of superconducting undulators continues at the Advanced Photon Source (APS). Two years after successful installation and commissioning of the first relatively short superconducting undulator “SCU0” in Sector 6 of the APS storage ring, the second 1.1-m-long superconducting undulator “SCU1...

[Phys. Rev. Accel. Beams 20, 100701] Published Tue Oct 03, 2017

Design of an $X$-band electron linear accelerator dedicated to decentralized $^{99}\mathrm{Mo}/^{99m}\mathrm{Tc}$ supply: From beam energy selection to yield estimation


Author(s): Jaewoong Jang, Masashi Yamamoto, and Mitsuru Uesaka

The most frequently used radionuclide in diagnostic nuclear medicine, $^{99m}\mathrm{Tc}$, is generally obtained by the decay of its parent radionuclide, $^{99}\mathrm{Mo}$. Recently, concerns have been raised over shortages of $^{99}\mathrm{Mo}{/}^{99m}\mathrm{Tc}$, owing to aging of the research r...

[Phys. Rev. Accel. Beams 20, 104701] Published Tue Oct 03, 2017

Publisher’s Note: Analytical description of photon beam phase spaces in inverse Compton scattering sources [Phys. Rev. Accel. Beams 20, 080701 (2017)]


Author(s): C. Curatolo, I. Drebot, V. Petrillo, and L. Serafini
[Phys. Rev. Accel. Beams 20, 109901] Published Tue Oct 03, 2017

4-twist helix snake to maintain polarization in multi-GeV proton rings


Author(s): F. Antoulinakis, Y. Chen, A. Dutton, E. Rossi De La Fuente, S. Haupert, E. A. Ljungman, P. D. Myers, J. K. Thompson, A. Tai, C. A. Aidala, E. D. Courant, A. D. Krisch, M. A. Leonova, W. Lorenzon, R. S. Raymond, D. W. Sivers, V. K. Wong, T. Yang, Y. S. Derbenev, V. S. Morozov, and A. M. Kondratenko

Solenoid Siberian snakes have successfully maintained polarization in particle rings below 1 GeV, but never in multi-GeV rings, because the spin rotation by a solenoid is inversely proportional to the beam momentum. High energy rings, such as Brookhaven’s 255 GeV Relativistic Heavy Ion Collider (RHI...

[Phys. Rev. Accel. Beams 20, 091003] Published Wed Sep 27, 2017

Control of systematic uncertainties in the storage ring search for an electric dipole moment by measuring the electric quadrupole moment


Author(s): Andrzej Magiera

Measurements of electric dipole moment (EDM) for light hadrons with use of a storage ring have been proposed. The expected effect is very small, therefore various subtle effects need to be considered. In particular, interaction of particle’s magnetic dipole moment and electric quadrupole moment with...

[Phys. Rev. Accel. Beams 20, 094001] Published Wed Sep 27, 2017

Analysis of multibunch free electron laser operation


Author(s): Thorsten Hellert, Winfried Decking, and Julien Branlard

At the SASE-FEL user facilities FLASH and European XFEL, superconducting TESLA type cavities are used for acceleration of the driving electron bunches. The high achievable duty cycle allows for operating with long bunch trains, hence considerably increasing the efficiency of the machine. However, mu...

[Phys. Rev. Accel. Beams 20, 090702] Published Tue Sep 26, 2017

Characterization of thermal neutron beam monitors


Author(s): F. Issa, A. Khaplanov, R. Hall-Wilton, I. Llamas, M. Dalseth Riktor, S. R. Brattheim, and H. Perrey

Neutron beam monitors with a wide range of efficiencies, low $γ$ sensitivity, and high time and space resolution are required in neutron beam experiments to continuously diagnose the delivered beam. In this work, commercially available neutron beam monitors have been characterized using the R2D2 bea...

[Phys. Rev. Accel. Beams 20, 092801] Published Tue Sep 26, 2017

Intense highly charged ion beam production and operation with a superconducting electron cyclotron resonance ion source


Author(s): H. W. Zhao, L. T. Sun, J. W. Guo, W. Lu, D. Z. Xie, D. Hitz, X. Z. Zhang, and Y. Yang

The superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is a superconducting-magnet-based electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged heavy ion beams. It is one of the best performing ECRISs worldwide and t...

[Phys. Rev. Accel. Beams 20, 094801] Published Thu Sep 21, 2017

Compensation of head-on beam-beam induced resonance driving terms and tune spread in the Relativistic Heavy Ion Collider


Author(s): W. Fischer, X. Gu, K. A. Drees, C. Liu, Y. Luo, A. Marusic, R. Michnoff, T. A. Miller, M. Minty, C. Montag, A. I. Pikin, G. Robert-Demolaize, V. Schoefer, P. Thieberger, and S. M. White

A head-on beam-beam compensation scheme was implemented for operation in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory [Phys. Rev. Lett. 115, 264801 (2015)]. The compensation consists of electron lenses for the reduction of the beam-beam induced tune spread, and a latt...

[Phys. Rev. Accel. Beams 20, 091001] Published Wed Sep 13, 2017

Modeling of beam-induced damage of the LHC tertiary collimators


Author(s): E. Quaranta, A. Bertarelli, R. Bruce, F. Carra, F. Cerutti, A. Lechner, S. Redaelli, E. Skordis, and P. Gradassi

Modern hadron machines with high beam intensity may suffer from material damage in the case of large beam losses and even beam-intercepting devices, such as collimators, can be harmed. A systematic method to evaluate thresholds of damage owing to the impact of high energy particles is therefore cruc...

[Phys. Rev. Accel. Beams 20, 091002] Published Wed Sep 13, 2017

Fabrication and cold test of dielectric assist accelerating structure


Author(s): D. Satoh, M. Yoshida, and N. Hayashizaki

We present the detailed description of a successful design and cold testing of the dielectric assist accelerating (DAA) structure. The DAA structure consists of ultralow-loss dielectric cylinders and disks with irises which are periodically arranged in a metallic enclosure. The advantage of the DAA ...

[Phys. Rev. Accel. Beams 20, 091302] Published Tue Sep 12, 2017

Optimizing density down-ramp injection for beam-driven plasma wakefield accelerators


Author(s): A. Martinez de la Ossa, Z. Hu, M. J. V. Streeter, T. J. Mehrling, O. Kononenko, B. Sheeran, and J. Osterhoff

Density down-ramp (DDR) injection is a promising concept in beam-driven plasma wakefield accelerators for the generation of high-quality witness beams. We review and complement the theoretical principles of the method and employ particle-in-cell (PIC) simulations in order to determine constrains on ...

[Phys. Rev. Accel. Beams 20, 091301] Published Wed Sep 06, 2017

Thermal considerations in the cryogenic regime for the BNL double ridge higher order mode waveguide


Author(s): Dhananjay K. Ravikumar, Yatming Than, Wencan Xu, and Jon Longtin

Brookhaven National Laboratory (BNL) has proposed to build an electron ion collider (EIC) as an upgrade to the existing Relativistic Heavy Ion Collider (RHIC). A part of the new design is to use superconducting radio frequency (SRF) cavities for acceleration, which sit in a bath of superfluid helium...

[Phys. Rev. Accel. Beams 20, 093201] Published Wed Sep 06, 2017

Matching-based fresh-slice method for generating two-color x-ray free-electron lasers


Author(s): Weilun Qin, Yuantao Ding, Alberto A. Lutman, and Yu-Chiu Chao

A two-color free-electron laser pulse can be generated in a split undulator configuration, where a controllable quadrupole wakefield induces a time-dependent mismatch along the bunch.

[Phys. Rev. Accel. Beams 20, 090701] Published Tue Sep 05, 2017

Digital low level rf control system with four different intermediate frequencies for the International Linear Collider


Author(s): Sigit Basuki Wibowo, Toshihiro Matsumoto, Shinichiro Michizono, Takako Miura, Feng Qiu, and Na Liu

A field programmable gate array–based digital low level rf (LLRF) control system will be used in the International Linear Collider (ILC) in order to satisfy the rf stability requirements. The digital LLRF control system with four different intermediate frequencies has been developed to decrease the ...

[Phys. Rev. Accel. Beams 20, 093501] Published Tue Sep 05, 2017

Space charge effects on the third order coupled resonance


Author(s): Giuliano Franchetti, Simone Gilardoni, Alexander Huschauer, Frank Schmidt, and Raymond Wasef

Periodic resonance crossing in higher dimensions explains beam loss observed in space charge dominated hadron-storage rings.

[Phys. Rev. Accel. Beams 20, 081006] Published Thu Aug 31, 2017

Application of transfer matrix and transfer function analysis to grating-type dielectric laser accelerators: Ponderomotive focusing of electrons


Author(s): Andrzej Szczepkowicz

The question of suitability of transfer matrix description of electrons traversing grating-type dielectric laser acceleration (DLA) structures is addressed. It is shown that although matrix considerations lead to interesting insights, the basic transfer properties of DLA cells cannot be described by...

[Phys. Rev. Accel. Beams 20, 081302] Published Thu Aug 31, 2017

Interaction region design driven by energy deposition


Author(s): Roman Martin, Maria Ilaria Besana, Francesco Cerutti, Andy Langner, Rogelio Tomás, Emilia Cruz-Alaniz, and Barbara Dalena

The European Strategy Group for High Energy Physics recommends to study collider designs for the post-LHC era. Among the suggested projects there is the circular 100 TeV proton-proton collider FCC-hh. Starting from LHC and its proposed upgrade HL-LHC, this paper outlines the development of the inter...

[Phys. Rev. Accel. Beams 20, 081005] Published Wed Aug 30, 2017

Suppression of stored-beam oscillation and observation of flux improvement during top-up injection


Author(s): Y-G. Son, J.-Y. Kim, C. Mitsuda, K. Kobayashi, J. Ko, T-Y. Lee, J-Y. Choi, D-E. Kim, H-S. Seo, H-S. Han, K-S. Park, C-D. Park, and S. Shin

This paper describes a start-to-end study of the suppression of stored-beam oscillation during top-up injection at the Pohang Light Source (PLS-II) beam line. The fast counterkicker implemented in PLS-II suppresses stored-beam oscillations in the vertical plane. During top-up injection in the magnet...

[Phys. Rev. Accel. Beams 20, 082803] Published Wed Aug 30, 2017

Effort towards symmetric removal and surface smoothening of 1.3-GHz niobium single-cell cavity in vertical electropolishing using a unique cathode


Author(s): Vijay Chouhan, Shigeki Kato, Keisuke Nii, Takanori Yamaguchi, Motoaki Sawabe, Hitoshi Hayano, and Yoshiaki Ida

A detailed study on vertical electropolishing (VEP) of a 1.3-GHz single-cell niobium coupon cavity, which contains six coupons and four viewports at different positions, is reported. The cavity was vertically electropolished using a conventional rod and three types of unique cathodes named as Ninja ...

[Phys. Rev. Accel. Beams 20, 083502] Published Tue Aug 29, 2017

High gain harmonic generation free electron lasers enhanced by pseudoenergy bands


Author(s): Takashi Tanaka and Ryota Kinjo

We propose a new scheme for high gain harmonic generation free electron lasers (HGHG FELs), which is seeded by a pair of intersecting laser beams to interact with an electron beam in a modulator undulator located in a dispersive section. The interference of the laser beams gives rise to a two-dimens...

[Phys. Rev. Accel. Beams 20, 080706] Published Thu Aug 24, 2017

Compact compressive arc and beam switchyard for energy recovery linac-driven ultraviolet free electron lasers


Author(s): J. A. G. Akkermans, S. Di Mitri, D. Douglas, and I. D. Setija

High gain free electron lasers (FELs) driven by high repetition rate recirculating accelerators have received considerable attention in the scientific and industrial communities in recent years. Cost-performance optimization of such facilities encourages limiting machine size and complexity, and a c...

[Phys. Rev. Accel. Beams 20, 080705] Published Wed Aug 23, 2017

Excitation of a nonlinear plasma ion wake by intense energy sources with applications to the crunch-in regime


Author(s): Aakash A. Sahai

We show the excitation of a nonlinear ion-wake mode by plasma electron modes in the bubble regime driven by intense energy sources, using analytical theory and simulations. The ion wake is shown to be a driven nonlinear ion-acoustic wave in the form of a long-lived cylindrical ion soliton which limi...

[Phys. Rev. Accel. Beams 20, 081004] Published Wed Aug 23, 2017

Large Hadron Collider momentum calibration and accuracy


Author(s): E. Todesco and J. Wenninger

As a result of the excellent quality of the Large Hadron Collider (LHC) experimental detectors and the accurate calibration of the luminosity at the LHC, uncertainties on the LHC beam energy may contribute significantly to the measurement errors on certain observables unless the relative uncertainty...

[Phys. Rev. Accel. Beams 20, 081003] Published Mon Aug 21, 2017

Ultraviolet laser transverse profile shaping for improving x-ray free electron laser performance


Author(s): S. Li, S. Alverson, D. Bohler, A. Egger, A. Fry, S. Gilevich, Z. Huang, A. Miahnahri, D. Ratner, J. Robinson, and F. Zhou

The photocathode rf gun is one of the most critical components in x-ray free electron lasers. The drive laser strikes the photocathode surface, which emits electrons with properties that depend on the shape of the drive laser. Most free electron lasers use photocathodes with work function in the ult...

[Phys. Rev. Accel. Beams 20, 080704] Published Thu Aug 17, 2017

Quasi-half-cycle pulses of light from a tapered undulator


Author(s): V. A. Goryashko

Strong-field few-cycle terahertz (THz) pulses are an invaluable tool for engineering highly nonequilibrium states of matter. A scheme is proposed to generate quasi-half-cycle GV/m-scale THz pulses with a multikilohertz repetition rate. It makes use of coherent spontaneous emission from a prebunched ...

[Phys. Rev. Accel. Beams 20, 080703] Published Tue Aug 15, 2017

Design of an rf quadrupole for Landau damping


Author(s): K. Papke and A. Grudiev

The recently proposed superconducting quadrupole resonator for Landau damping in accelerators is subjected to a detailed design study. The optimization process of two different cavity types is presented following the requirements of the High Luminosity Large Hadron Collider (HL-LHC) with the main fo...

[Phys. Rev. Accel. Beams 20, 082001] Published Tue Aug 15, 2017

Low-emittance thermionic-gun-based injector for a compact free-electron laser


Author(s): Takao Asaka, Hiroyasu Ego, Hirohumi Hanaki, Toru Hara, Taichi Hasegawa, Teruaki Hasegawa, Takahiro Inagaki, Toshiaki Kobayashi, Chikara Kondo, Hirokazu Maesaka, Shinichi Matsubara, Sakuo Matsui, Takashi Ohshima, Yuji Otake, Tatsuyuki Sakurai, Shinsuke Suzuki, Yasuyuki Tajiri, Shinichiro Tanaka, Kazuaki Togawa, and Hitoshi Tanaka

A low-emittance thermionic-gun-based injector was developed for the x-ray free-electron laser (XFEL) facility known as the SPring-8 angstrom compact free-electron laser (SACLA). The thermionic-gun-based system has the advantages of maintainability, reliability, and stability over a photocathode radi...

[Phys. Rev. Accel. Beams 20, 080702] Published Mon Aug 14, 2017

Final implementation, commissioning, and performance of embedded collimator beam position monitors in the Large Hadron Collider


Author(s): Gianluca Valentino, Guillaume Baud, Roderik Bruce, Marek Gasior, Alessio Mereghetti, Daniele Mirarchi, Jakub Olexa, Stefano Redaelli, Belen Salvachua, Alessandra Valloni, and Jorg Wenninger

During Long Shutdown 1, 18 Large Hadron Collider (LHC) collimators were replaced with a new design, in which beam position monitor (BPM) pick-up buttons are embedded in the collimator jaws. The BPMs provide a direct measurement of the beam orbit at the collimators, and therefore can be used to align...

[Phys. Rev. Accel. Beams 20, 081002] Published Thu Aug 10, 2017

Direct injection of fully stripped carbon ions into a fast-cycling induction synchrotron and their capture by the barrier bucket


Author(s): N. Munemoto, S. Takano, E. Kadokura, Taufik, T. Yoshimoto, X. Liu, T. Adachi, M. Ikeda, T. Kawakubo, K. Okamura, K. Takayama, and M. Wake

Fully stripped carbon ions generated in a laser-ablation ion source are directly injected into a small-scale induction synchrotron. Carbon-ion beams of ${\mathrm{C}}^{6+}$, ${\mathrm{C}}^{5+}$, and ${\mathrm{C}}^{4+}$ are trapped in the barrier bucket. Beam properties, such as the momentum spread an...

[Phys. Rev. Accel. Beams 20, 080101] Published Wed Aug 09, 2017

rf measurements and tuning of the 750 MHz radio frequency quadrupole


Author(s): Benjamin Koubek, Alexej Grudiev, and Marc Timmins

In the framework of the program on medical applications a compact 750 MHz RFQ has been designed and built to be used as an injector for a hadron therapy linac. This RFQ was designed to accelerate protons to an energy of 5 MeV within only 2 m length. It is divided into four segments and equipped with...

[Phys. Rev. Accel. Beams 20, 080102] Published Wed Aug 09, 2017

Numerical simulations of energy deposition caused by 50 MeV—50 TeV proton beams in copper and graphite targets


Author(s): Y. Nie, R. Schmidt, V. Chetvertkova, G. Rosell-Tarragó, F. Burkart, and D. Wollmann

The conceptual design of the Future Circular Collider (FCC) is being carried out actively in an international collaboration hosted by CERN, for the post–Large Hadron Collider (LHC) era. The target center-of-mass energy of proton-proton collisions for the FCC is 100 TeV, nearly an order of magnitude ...

[Phys. Rev. Accel. Beams 20, 081001] Published Wed Aug 09, 2017

Manipulation of laser-accelerated proton beam profiles by nanostructured and microstructured targets


Author(s): L. Giuffrida, K. Svensson, J. Psikal, M. Dalui, H. Ekerfelt, I. Gallardo Gonzalez, O. Lundh, A. Persson, P. Lutoslawski, V. Scuderi, J. Kaufman, T. Wiste, T. Lastovicka, A. Picciotto, A. Bagolini, M. Crivellari, P. Bellutti, G. Milluzzo, G. A. P. Cirrone, J. Magnusson, A. Gonoskov, G. Korn, C-G. Wahlström, and D. Margarone

Nanostructured and microstructured thin foils have been fabricated and used experimentally as targets to manipulate the spatial profile of proton bunches accelerated through the interaction with high intensity laser pulses ($6×{10}^{19}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$). Monolayers of po...

[Phys. Rev. Accel. Beams 20, 081301] Published Fri Aug 04, 2017

Improving the precision of linear optics measurements based on turn-by-turn beam position monitor data after a pulsed excitation in lepton storage rings


Author(s): L. Malina, J. Coello de Portugal, T. Persson, P. K. Skowroński, R. Tomás, A. Franchi, and S. Liuzzo

Beam optics control is of critical importance for machine performance and protection. Nowadays, turn-by-turn (TbT) beam position monitor (BPM) data are increasingly exploited as they allow for fast and simultaneous measurement of various optics quantities. Nevertheless, so far the best documented un...

[Phys. Rev. Accel. Beams 20, 082802] Published Fri Aug 04, 2017

Analytical description of photon beam phase spaces in inverse Compton scattering sources


Author(s): C. Curatolo, I. Drebot, V. Petrillo, and L. Serafini

We revisit the description of inverse Compton scattering sources and the photon beams generated therein, emphasizing the behavior of their phase space density distributions and how they depend upon those of the two colliding beams of electrons and photons. The main objective is to provide practical ...

[Phys. Rev. Accel. Beams 20, 080701] Published Thu Aug 03, 2017

New solution for the high accuracy alignment of accelerator components


Author(s): D. Caiazza, N. Catalan Lasheras, H. Mainaud Durand, M. Modena, C. Sanz, D. Tshilumba, V. Vlachakis, M. Wendt, and S. Zorzetti

Several state-of-the-art metrology measurement methods have been investigated and combined for a fiducialization of accelerator components in the micrometric regime. The PACMAN project at CERN applied stretched-wire measurement methods to Compact Linear Collider quadrupole and cavity beam position m...

[Phys. Rev. Accel. Beams 20, 083501] Published Thu Aug 03, 2017

Reversible beam heater for suppression of microbunching instability by transverse gradient undulators


Author(s): Tao Liu, Weilun Qin, Dong Wang, and Zhirong Huang

The microbunching instability driven by beam collective effects in a linear accelerator of a free-electron laser (FEL) facility significantly degrades the electron beam quality and FEL performance. A conventional method to suppress this instability is to introduce an additional uncorrelated energy s...

[Phys. Rev. Accel. Beams 20, 082801] Published Wed Aug 02, 2017

Permanent magnet based dipole magnets for next generation light sources


Author(s): Takahiro Watanabe, Tsutomu Taniuchi, Shiro Takano, Tsuyoshi Aoki, and Kenji Fukami

We have developed permanent magnet based dipole magnets for the next generation light sources. Permanent magnets are advantageous over electromagnets in that they consume less power, are physically more compact, and there is a less risk of power supply failure. However, experience with electromagnet...

[Phys. Rev. Accel. Beams 20, 072401] Published Mon Jul 31, 2017

Chromaticity effects on head-tail instabilities for broadband impedance using two particle model, Vlasov analysis, and simulations


Author(s): Yong Ho Chin, Alexander Wu Chao, Michael M. Blaskiewicz, and Yoshihiro Shobuda

Effects of the chromaticity on head-tail instabilities for broadband impedances are comprehensively studied, using the two particle model, the Vlasov analysis and computer simulations. We show both in the two particle model and the Vlasov analysis with the trapezoidal (semiconstant) wake model that ...

[Phys. Rev. Accel. Beams 20, 071003] Published Fri Jul 28, 2017

Thermally assisted photoemission effect on ${\mathrm{CeB}}_{6}$ and ${\mathrm{LaB}}_{6}$ for application as photocathodes


Author(s): K. Torgasin, K. Morita, H. Zen, K. Masuda, T. Katsurayama, T. Murata, S. Suphakul, H. Yamashita, T. Nogi, T. Kii, K. Nagasaki, and H. Ohgaki

The thermally assisted photoemission (TAPE) effect was investigated for the hexaboride thermionic cathodes (${\mathrm{LaB}}_{6}$ and ${\mathrm{CeB}}_{6}$). It was found that the quantum efficiency of these cathodes can be increased by raising the cathode temperature along with the thermionic emissio...

[Phys. Rev. Accel. Beams 20, 073401] Published Tue Jul 25, 2017

Using a Bessel light beam as an ultrashort period helical undulator


Author(s): B. C. Jiang, Q. L. Zhang, J. H. Chen, and Z. T. Zhao

An undulator is a critical component to produce synchrotron radiation and a free electron laser. When a Bessel light beam carrying the orbit angular momentum copropagates with an electron beam bunch, a net transverse deflection force will be subjected to the latter one. As a result of dephasing effe...

[Phys. Rev. Accel. Beams 20, 070701] Published Mon Jul 24, 2017

Analysis of emissions from prebunched electron beams


Author(s): Jia Qika

The emissions of the prebunched electron beam, including the coherent spontaneous emission and the self-amplified stimulated emission, are analyzed by using one-dimensional FEL theory. Neglecting the interaction of the electrons and the radiation field, the formula of the coherent spontaneous emissi...

[Phys. Rev. Accel. Beams 20, 070702] Published Mon Jul 24, 2017

Proton irradiated graphite grades for a long baseline neutrino facility experiment


Author(s): N. Simos, P. Nocera, Z. Zhong, R. Zwaska, N. Mokhov, J. Misek, K. Ammigan, P. Hurh, and Z. Kotsina

In search of a low-Z pion production target for the Long Baseline Neutrino Facility (LBNF) of the Deep Underground Neutrino Experiment (DUNE) four graphite grades were irradiated with protons in the energy range of 140–180 MeV, to peak fluence of $∼6.1×{10}^{20}\text{ }\text{ }\mathrm{p}/{\mathrm{cm...

[Phys. Rev. Accel. Beams 20, 071002] Published Mon Jul 24, 2017

Dynamics of microparticles in vacuum breakdown: Cranberg’s scenario updated by numerical modeling


Author(s): B. Seznec, Ph. Dessante, T. Jager, L. Caillault, Ph. Teste, and T. Minea

Microparticles (MP) and thermofield emission in vacuum are mainly caused by the roughness present at the surface of electrodes holding a high voltage. They can act as a trigger for breakdown, especially under high vacuum. This theoretical study discusses the interactions between one MP and the therm...

[Phys. Rev. Accel. Beams 20, 073501] Published Mon Jul 24, 2017

Crystal collimator systems for high energy frontier


Author(s): A. I. Sytov, V. V. Tikhomirov, and A. S. Lobko

Crystalline collimators can potentially considerably improve the cleaning performance of the presently used collimator systems using amorphous collimators. A crystal-based collimation scheme which relies on the channeling particle deflection in bent crystals has been proposed and extensively studied...

[Phys. Rev. Accel. Beams 20, 071001] Published Thu Jul 13, 2017

Erratum: Eigenmode compendium of the third harmonic module of the European X-ray Free Electron Laser [Phys. Rev. Accel. Beams 20, 042002 (2017)]


Author(s): Thomas Flisgen, Johann Heller, Tomasz Galek, Liangliang Shi, Nirav Joshi, Nicoleta Baboi, Roger M. Jones, and Ursula van Rienen
[Phys. Rev. Accel. Beams 20, 079901] Published Thu Jul 13, 2017

Spin tune mapping as a novel tool to probe the spin dynamics in storage rings


Author(s): A. Saleev et al. (JEDI collaboration)

The stable spin direction of polarized particles in a storage ring was determined first experimentally, through an accurate measurement of the spin tune and its response to longitudinal magnetic fields.

[Phys. Rev. Accel. Beams 20, 072801] Published Fri Jul 07, 2017

Hamiltonian approach to slip-stacking dynamics


Author(s): S. Y. Lee and K. Y. Ng

Hamiltonian dynamics has been applied to study the slip-stacking dynamics. The canonical-perturbation method is employed to obtain the second-harmonic correction term in the slip-stacking Hamiltonian. The Hamiltonian approach provides a clear optimal method for choosing the slip-stacking parameter a...

[Phys. Rev. Accel. Beams 20, 064202] Published Thu Jun 29, 2017

Challenges of in-vacuum and cryogenic permanent magnet undulator technologies


Author(s): Jui-Che Huang, Hideo Kitamura, Chin-Kang Yang, Cheng-Hsing Chang, Cheng-Hsiang Chang, and Ching-Shiang Hwang

An in-vacuum undulator (IVU) provides a means to reach high-brilliance x rays in medium energy storage rings. The development of short period undulators with low phase errors creates the opportunity for an unprecedented brilliant light source in a storage ring. Since the spectral quality from cryoge...

[Phys. Rev. Accel. Beams 20, 064801] Published Thu Jun 29, 2017

Phase jump method for efficiency enhancement in free-electron lasers


Author(s): Alan Mak, Francesca Curbis, and Sverker Werin

The efficiency of a free-electron laser can be enhanced by the phase jump method. The method utilizes the phase-shifting chicanes in the drift sections between the undulator segments. By applying appropriate phase jumps, the microbunched electron beam can decelerate and radiate coherently beyond the...

[Phys. Rev. Accel. Beams 20, 060703] Published Thu Jun 22, 2017

Coherent resonance stop bands in alternating gradient beam transport


Author(s): K. Ito, H. Okamoto, Y. Tokashiki, and K. Fukushima

An extensive experimental study is performed to confirm fundamental resonance bands of an intense hadron beam propagating through an alternating gradient linear transport channel. The present work focuses on the most common lattice geometry called “FODO” or “doublet” that consists of two quadrupoles...

[Phys. Rev. Accel. Beams 20, 064201] Published Thu Jun 22, 2017

Achievement of a low-loss 1-MW beam operation in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex


Author(s): H. Hotchi, H. Harada, N. Hayashi, S. Kato, M. Kinsho, K. Okabe, P. K. Saha, Y. Shobuda, F. Tamura, N. Tani, Y. Watanabe, K. Yamamoto, M. Yamamoto, and M. Yoshimoto

The 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) is now in the final beam commissioning phase, aiming for a design output beam power of 1 MW. With a series of injector linac upgrades in 2013 and 2014, RCS developed a high-intensity beam test, and la...

[Phys. Rev. Accel. Beams 20, 060402] Published Mon Jun 19, 2017

Direct measurement of the image displacement instability in a linear induction accelerator


Author(s): T. J. Burris-Mog, C. A. Ekdahl, and D. C. Moir

The image displacement instability (IDI) has been measured on the 20 MeV Axis I of the dual axis radiographic hydrodynamic test facility and compared to theory. A 0.23 kA electron beam was accelerated across 64 gaps in a low solenoid focusing field, and the position of the beam centroid was measured...

[Phys. Rev. Accel. Beams 20, 060403] Published Mon Jun 19, 2017

Sensitivity of echo enabled harmonic generation to sinusoidal electron beam energy structure


Author(s): E. Hemsing, B. Garcia, Z. Huang, T. Raubenheimer, and D. Xiang

We analytically examine the bunching factor spectrum of a relativistic electron beam with sinusoidal energy structure that then undergoes an echo-enabled harmonic generation (EEHG) transformation to produce high harmonics. The performance is found to be described primarily by a simple scaling parame...

[Phys. Rev. Accel. Beams 20, 060702] Published Mon Jun 19, 2017