IPAC2016 - Classification: 05 Beam Dynamics and Electromagnetic Fields / D11 Code Developments and Simulation Techniques

Paper	Title	Page
TUXB01	High Power Radiation Sources using the Steady-state Microbunching Mechanism	1048
	A. Chao, E. Granados, X. Huang, D.F. Ratner SLAC, Menlo Park, California, USA H.W. Luo NTHU, Hsinchu, Taiwan
	The mechanism of steady-state microbunching (SSMB) was proposed for providing high power coherent radiation using electron storage rings. The mechanism follows closely the RF bunching in conventional storage rings, except that the energy modulation of by an RF system at a microwave wavelength is replaced by a seeded laser in an undulator at an optical wavelength. No FEL mechanism, and thus no FEL energy heating, is invoked. The basic idea is firstly to make the beam microbunched so that its radiation becomes coherent, and secondly to make the microbunching a steady state so that the coherent radiation is maintained at every turn. The combination of the high repetition rate of a storage ring and the enhanced radiation power by a factor of N (the number of electrons in the microbunches within one coherence length) opens the possibility as well as challenges of very high power SSMB sources. To explore its potential reach, we apply SSMB to the infrared, deep ultraviolet and EUV regions and estimate their respective power levels using SPEAR3 as example. Several variants of the SSMB schemes are discussed. A proof-of-principle configuration without an identified testbed is also suggested.
	Slides TUXB01 [1.602 MB]
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WEPMY043	Parallel Particle Movement Simulation Algorithm Based on Heterogeneous Computing	2654
	L.G. Zhang, L. Cao, K. Fan, J. Huang, K.F. Liu, W. Qi, J. Yang HUST, Wuhan, People's Republic of China
	Particle in cell (PIC) algorithm studies the self-consistent motion of multi-particle system by solving equations of particle dynamics, this algorithm is widely used to evaluate the nonlinear space charge effect of the high intensity or low energy beam. In order to reduce the random noise in the simulation, a huge number of particles should be traced, the process expends many computer hardware resources and a lot of computing time. Heterogeneous computing can greatly improve the efficiency of large quantities of the particle tracking by making full use of different types of computing resources. In this paper we give the algorithm which uses both CPU and GPU to trace the particles in electromagnetic field. The results show that the given algorithm increases the efficiency significantly.
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WEPOY002	A Time Domain Analysis Method for RF Noise	2994
	L. Lin, B. Du, G. Huang, Y.T. Liu USTC/NSRL, Hefei, Anhui, People's Republic of China
	A time domain analysis method is developed for the calculation of the longitudinal oscillations caused by the RF noise in the storage ring. This method is based on the impulse response model, and it could calculates the change of transient field caused by beam oscillation and RF noise turn by turn. By means of discrete spectrum analysis, the spectrum of the beam is obtained. According to this analysis method, we developed a simulation pro-gram. The synchronous oscillation of the excited by high RF source with a phase modulation is predicted in this program, and the corresponding experimental measure-ments are carried out on HLS II. The fitting results are in agreed with the experimental measurements.
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WEPOY026	Simulation and Measurement of the Beam Breakup Instability in a W-band Corrugated Structure	3044
	D. Wang, C.-X. Tang TUB, Beijing, People's Republic of China S.P. Antipov, C.-J. Jing, J.Q. Qiu Euclid TechLabs, LLC, Solon, Ohio, USA M.E. Conde, D.S. Doran, W. Gai, G. Ha, W. Liu, J.G. Power, E.E. Wisniewski ANL, Argonne, Illinois, USA
	The corrugated wakefield structure has wide application in electron beam energy manipulation and high frequency RF radiation generation. The transverse wakefield which cause beam breakup (BBU) instability is excited when the drive beam is not perfectly centered through the structure. Here we report on the numerical and experimental investigation of the BBU effect in a W-band corrugated structure, for both cases of short range wakefield and long range wakefield. In the numerical part we develop a point to point (P2P) code that allows rapid and efficiency simulations of the beam dynamics effect by wakefield, which is based on the the particle-wake function coupled dynamics equation of motion. And the experimental measurements of BBU effect are found to be in good agreement with the simulations.
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WEPOY033	Space Charge Compensation in Low Energy Beam Lines	3055
SUPSS065	use link to see paper's listing under its alternate paper code
	F. Gérardin, N. Chauvin, D. Uriot CEA/IRFU, Gif-sur-Yvette, France M.A. Baylac, D. Bondoux, F. Bouly LPSC, Grenoble Cedex, France A. Chancé, O. Napoly, N. Pichoff CEA/DSM/IRFU, France
	The dynamics of a high intensity beam with low energy is governed by its space-charge forces which may be responsible of emittance growth and halo formation due to their non-linearity. In a low energy beam transport (LEBT) line of a linear accelerator, the propagation of a charged beam with low energy causes the production of secondary particles created by the interaction between the beam and the background gas present in the accelerator tube. This phenomenon called space-charge compensation is difficult to characterize analitically. In order to obtain some quantitative to characterize the space-charge compensation (or neutralization), numerical simulations using a 3D PIC code have been implemented.
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WEPOY034	Latest Improvements of OPAL	3058
	C.J. Metzger-Kraus, M. Abo-Bakr, B.C. Kuske HZB, Berlin, Germany A. Adelmann PSI, Villigen PSI, Switzerland
	OPAL (Object Oriented Parallel Accelerator Library) is an open source, C++ based tool for charged particle tracking in large accelerator structures and beam lines including 3D space charge, particle matter interaction and FFAG capabilities. The careful parallel design makes it possible to tackle large and complex problems, in a reasonable time frame. The current code status and latest program improvements and upgrades are introduced. One of the provided flavors, OPAL-T, was, so-far, used for relatively simple lattices and was not well suited for more complicated arrangements of elements. One of the major upgrades is the possibility to place elements in 3D space, giving the user a better control in absolute element positioning. The old input format with relative positioning is still supported. We show results of the BERLinPro lattice and compare it with results obtained with elegant.
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WEPOY035	Free Electron Laser Simulation Tool Based on FDTD/PIC in the Lorentz Boosted Frame	3061
	A. Yahaghi, A. Fallahi, F.X. Kärtner CFEL, Hamburg, Germany F.X. Kärtner MIT, Cambridge, Massachusetts, USA
	Funding: Alexander von Humboldt-Foundation European Research Council(ERC) Free Electron Lasers (FELs) are promising sources capable of generating electromagnetic waves in the whole spectrum. Therefore, it is crucial and additionally very useful to develop sophisticated though complete simulation tools. This goal is mainly motivated by our research focus on the development of compact X-ray sources based on radiation in optical undulators. The currently existing softwares are usually written to tackle special cases with particular approximations, such as 1D FEL theory, steady state, slow wave and forward wave approximation, wiggler-averaged electron motion and slices approximation. Many of the above approximations are hardly valid when sub-femtosecond bunches interact with intense optical lasers. The presented software aims the analysis of the FEL interaction without considering any of the above approximations. The developed tool apparently suffers from long computation times but offers a more accurate picture on the radiation process. In order to overcome the problem of multidimensionality, we exploit Lorentz boosted coordinate system and implement Finite Difference Time Domain (FDTD) method combined with Particle in Cell (PIC) simulation in this frame.
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WEPOY036	Progress in Automatic Software-based Optimization of Accelerator Performance	3064
	S.I. Tomin, G. Geloni XFEL. EU, Hamburg, Germany I.V. Agapov, I. Zagorodnov DESY, Hamburg, Germany W.S. Colocho, T.M. Cope, A.B. Egger, D.F. Ratner SLAC, Menlo Park, California, USA Y.A. Fomin, Y.V. Krylov, A.G. Valentinov NRC, Moscow, Russia
	Funding: partial support from Ioffe Roentgen Institute grant EDYN EMRAD For modern linac- and storage-ring-based light sources certain amount of empirical tuning is used to reach ultimate performance. The possibility to perform such empirical tuning by automatic methods has now been demonstrated by several authors (e.g. I.Agapov et al. in proc IPAC 2015). In this paper we present the progress in development of our automatic optimisation software based on OCELOT and its applications to SASE FEL optimization at FLASH and LCLS, and its potential for storage ring optimization.
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WEPOY037	Optimization of THz Radiation Pulses at FLUTE	3067
	M. Yan, A.-S. Müller, M.J. Nasse, M. Schuh, M. Schwarz KIT, Karlsruhe, Germany
	The accelerator test facility FLUTE (Ferninfrarot Linac Und Test Experiment) will allow research and development in electron accelerator technology as well as photon science. Electron bunches of durations in the femtosecond range will be provided to generate intense THz radiation. Start-to-end simulation of the accelerator has been performed with the bunch length as the optimization objective. Based on the resulting charge distribution the expected THz field properties can be calculated. In this paper we combine the two tools and present first results.
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WEPOY038	Design of a Collection and Selection System for High Energy Laser-Driven Ion Beams	3070
	F. Schillaci, G.A.P. Cirrone, G. Cuttone, D. Rifuggiato INFN/LNS, Catania, Italy M. Maggiore INFN/LNL, Legnaro (PD), Italy
	Laser-based accelerators are gaining interest in recent years as an alternative to conventional machines. Nowadays, energy and angular spread of the laser-driven beams are the main issues in application and different solutions for dedicated beam-transport lines have been proposed. In this context a system of permanent magnet quadrupoles has been realized, by INFN researchers in collaboration with SIGMAPHI company, to be used as a collection system for laser-driven protons up to 20 MeV. The definition of well specified characteristics, in terms of performances and field quality, of the magnetic lenses is crucial for the system realization and an accurate study of the beam dynamics. Hence, a method for studying the errors on the PMQ harmonic contents has been developed. It consists of different series of simulations in which magnetic and mechanical errors are introduced in the array and the harmonic content is analyzed to fix the tolerances necessary to have a good beam quality downstream the system. The method developed for the analysis of the PMQs errors and its validation is here described. The technique is general and can be easily extended to any magnetic lens.
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WEPOY039	GIOTTO: A Genetic Code for Demanding Beam-dynamics Optimizations	3073
	A. Bacci Istituto Nazionale di Fisica Nucleare, Milano, Italy V. Petrillo Universita' degli Studi di Milano, Milano, Italy M. Rossetti Conti Universita' degli Studi di Milano & INFN, Milano, Italy
	GIOTTO is a software based on a Genetic Algorithm (GA). Its development started in 2007 with a work published on NIMB (263, 2007, 488-496) and presented at PAC07 (THPAN031). When the parameters, defining an acceleration machine beam line, are strongly correlated in nonlinear way, the GAs are a powerful tool to coup with these difficulties. These conditions are typically generated by space-charge, as in the high brightness e-beam photo-injectors or when the Velocity Bunching compression technique (VB) is used. The power of GIOTTO is the adaptability to different cases, given by its own structure that permits to drive different external codes in series, the possibility to define a user dependent multi objective fitness function and function constraints on the beam dynamics, as well as the possibility to turn off the genetic optimization to perform statistical analysis (machine jitters). Up today it has been used in Thomson/Compton sources, ultra-short e-bunches generation by VB, focusing channel and dog-leg lines optimizations.
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WEPOY040	Lattice Translation Between Accelerator Simulation Codes for Superkekb	3077
	D. Zhou, H. Koiso, A. Morita, Y. Ohnishi, K. Oide, H. Sugimoto KEK, Ibaraki, Japan M.E. Biagini INFN/LNF, Frascati (Roma), Italy N. Carmignani, S.M. Liuzzo ESRF, Grenoble, France D. Sagan Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	To improve collaborative studies on beam dynamics for SuperKEKB between several labs, efforts have been made to translate the SAD lattices of SuperKEKB rings to the versions for other codes: AT, Bmad, MAD-X, and PTC. It turns out that lattice translations between these codes are not straightforward because of the complexity of the SuperKEKB lattices. In this paper, we describe our experiences of lattice translations, and present some results of benchmarks for the case of SuperKEKB.
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WEPOY041	Fast Tracking of Nonlinear Dynamics in the ESS Linac Simulator via Particle-Count Invariance	3080
SUPSS063	use link to see paper's listing under its alternate paper code
	B.T. Folsom, E. Laface ESS, Lund, Sweden
	Real-time beam modeling has been used in accelerator diagnostics for several decades. Along the way, the theory for matrix calculations of linear forces has matured, allowing for fast calculations of a beam's momentum and position distributions. This formalism becomes complicated and ultimately breaks down with high-order beam elements like sextupoles. Such elements can be accurately modeled with a Lie-algebra approach, but these techniques are generally implemented in slower, offline multiparticle tracking software. Here, we demonstrate an adaptation of the conventional Lie techniques for rapid first-order tracking of position, which is accomplished by treating a bunch's particle count as an invariant.
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WEPOY042	Open XAL Status Report 2016	3083
	T.A. Pelaia II, C.K. Allen, A.P. Shishlo, A.P. Zhukov ORNL, Oak Ridge, Tennessee, USA D.A. Brown NMSU, Las Cruces, New Mexico, USA Y.-C. Chao TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada C.P. Chu, Y. Zhang FRIB, East Lansing, Michigan, USA P. Gillette, P. Laurent, E. Lécorché, G. Normand GANIL, Caen, France E. Laface, Y.I. Levinsen, M. Muñoz ESS, Lund, Sweden Y. Li IHEP, Beijing, People's Republic of China I. List, M. Pavleski Cosylab, Ljubljana, Slovenia X.H. Lu CSNS, Guangdong Province, People's Republic of China
	Funding: This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC0500OR22725 with the U.S. Department of Energy. Formed in 2010, the Open XAL accelerator physics software platform was developed through an international collaboration among several facilities to establish it as a standard for accelerator physics software. While active development continues, the project has now matured. This paper presents the current status of the project, a roadmap for continued development and an overview of the project status at each participating facility.
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WEPOY044	Review of CPU and GPU Faddeeva Implementations	3090
	A. Oeftiger, R. De Maria, L. Deniau, K.S.B. Li, E. McIntosh, L. Moneta CERN, Geneva, Switzerland A. Aviral BITS Pilani, Pilani, India S. Hegglin ETH, Zurich, Switzerland A. Oeftiger EPFL, Lausanne, Switzerland
	Funding: CERN, Doctoral Studentship EPFL, Doctorate The Faddeeva error function is frequently used when computing electric fields generated by two-dimensional Gaussian charge distributions. Numeric evaluation of the Faddeeva function is particularly challenging since there is no single expansion that converges rapidly over the whole complex domain. Various algorithms exist, even in the recent literature there have been new proposals. The many different implementations in computer codes offer different trade-offs between speed and accuracy. We present an extensive benchmark of selected algorithms and implementations for accuracy, speed and memory footprint, both for CPU and GPU architectures.
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WEPOY045	Benchmarking the Beam Longitudinal Dynamics Code BLonD	3094
	H. Timko, J.F. Esteban Müller, A. Lasheen, D. Quartullo CERN, Geneva, Switzerland
	The relatively recent Beam Longitudinal Dynamics code BLonD has already been applied to a wide range of studies for all present CERN synchrotrons. Its application area ranges from studies of RF manipulations, over single and multi-bunch interactions with impedance, to the action of feedback loops and RF noise. In this paper, we present benchmarks and comparisons with measurements, theory, or other codes, which have increased greatly the trust in the code. Tests related to bunch-to-bucket transfer, feedback loops, diffusion due to noise injection, as well as collective effects, are presented.
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WEPOY046	Beam Delivery Simulation: BDSIM - Automatic Geant4 Models of Accelerators	3098
	L.J. Nevay, S.T. Boogert, L.C. Deacon, S.M. Gibson, R. Kwee-Hinzmann, W. Shields, J. Snuverink JAI, Egham, Surrey, United Kingdom H. Garcia CERN, Geneva, Switzerland
	Beam Delivery Simulation (BDSIM) is a program that uses a suite of high energy physics software including Geant4, CLHEP & ROOT, that seamlessly tracks particles through accelerators and detectors utilising the full range of particles and physics processes from Geant4. BDSIM has been used to simulate linear colliders such as the International Linear Collider (ILC) and more recently, circular colliders such as the Large Hadron Collider (LHC). The latest developments including improved geometry modelling; external geometry support; process biasing; and a new event display are presented. A significantly revised and improved accompanying tool chain is presented comprising of a series of Python utilities that allow efficient and automatic preparation of models. Furthermore, a library for both ROOT and Python that provides powerful analysis and event viewing after simulation is demonstrated.
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WEPOY048	Overview of the Design of the IBEX Linear Paul Trap	3104
	S.L. Sheehy JAI, Oxford, United Kingdom D.J. Kelliher, S. Machida, D.C. Plostinar, C.R. Prior STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	We report on the status and design of the Intense Beam Experiment (IBEX) at RAL. This experiment consists of a linear Paul trap apparatus similar to the S-POD system at University of Hiroshima, confining non-neutral Argon plasma in an RF quadrupole field. The physical equivalence between this device and a beam in a linear focusing channel makes it a useful tool for accelerator physics studies including resonances and high intensity effects. We give an overview of the design and construction of IBEX and outline plans for commissioning and the future experimental programme.
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WEPOY050	A Differential Algebraic Framework for the Fast Indirect Boundary Element Method	3107
SUPSS064	use link to see paper's listing under its alternate paper code
	A.J. Gee, B. Erdelyi Northern Illinois University, DeKalb, Illinois, USA B. Erdelyi ANL, Argonne, USA
	Beam physics at the intensity frontier must account for the beams' realistic surroundings on their dynamics in an accurate and efficient manner. Mathematically, the problem can be expressed as a Poisson PDE with given boundary conditions. Commonly, the Poisson boundary value problem is solved locally within many volume elements. However, it is known the PDE may be re-expressed as indirect bound- ary integral equations (BIE) which give a global solution. By solving the BIEs on M surface elements, we arrive at the indirect boundary element method (iBEM). Iteratively solving this dense linear system of form Ax = b scales like (m_iterations M² ). Accelerating with the fast multipole method (FMM) can reduce this to O(M) if m_iterations << M. For N evaluation points, the total complexity would be O(M) + O(N) or O(N) with N = M. We have implemented a constant element version of this fast iBEM based on our previous work with the FMM in the differential algebraic (DA) framework. This implementation is to illustrate the flexibility and accuracy of our method. A future version will focus on allowing for higher order elements. Sauter, S. and C. Schwab. Boundary Element Methods (2011) ** Abeyratne, S., S. Manikonda, and B. Erdelyi. "A novel differential algebraic adaptive fast multipole method." IPAC 2013: 1055-1057.
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WEPOY051	Performance Optimization of Multi-particle Beam Dynamics Code IMPACT-Z on NVidia GPGPU	3110
	Z.Q. He, G. Shen, Y. Yamazaki FRIB, East Lansing, Michigan, USA X. Wang ICER, MSU, East Lansing, USA
	Funding: The work is supported by the U.S. National Science Foundation , the U.S. Department of Energy Office of Science, the Institute for Cyber-Enabled Research, MSU. Facility for Rare Isotope Beams is designed using a multiparticle tracking code IMPACT-Z. IMPACT-Z is originally for the purpose of accelerator design, so it is precise, however, quite time consuming, therefore usually not suitable for on-line beam tuning applications. IMPACT-Z is originally boosted using Message Passing Interface (MPI) technology. For single node mode, performance of IMPACT-Z is usually bounded by CPU performance, and for multimode mode, communication between MPI processes would become bottleneck. However, new emerging High Performance Computing (HPC) technology, like general-purpose graphics processing unit (GPGPU), brings new possibility in accelerating IMPACT-Z, so that the speed of IMPACT-Z satisfies for on-line beam tuning applications. This paper presents the efforts in exploring the capability of Nvidia GPGPU and the results of speed up of IMPACT-Z.
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WEPOY053	Comparison of Tracking Codes for the Determination of Dynamic Aperture in Storage Rings	3114
	R. Hipple, M. Berz MSU, East Lansing, Michigan, USA
	Funding: This work is supported by the U.S. Department of Energy under grant number DE-FG02-08ER41546 Currently there is a great deal of activity towards making precision measurements utilizing storage rings, for example the Muon g-2 experiment at Fermilab, and the Electric Dipole Moment (EDM) program of the JEDI Collaboration. These experiments are intended to perform measurements requiring sub-ppm precision. Of utmost importance in this regard is the ability of tracking codes to treat all nonlinear effects arising from the detailed field distributions present in the system, not the least of which are fringe fields. In previously published work,,, we performed parallel tests of various tracking codes in order to compare and contrast the results. In this study, we continue this line of research and extend the scope to parallel-faced dipoles and electrostatic dipoles. R.Hipple, M. Berz, Microscopy and Microanalysis 21 Suppl. 4 (2015) ** R. Hipple, M.Berz, MODBC3, ICAP 2015, in press.
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WEPOY054	A Matlab Interface Package for Elegant Simulation Code	3117
	V.V. Smaluk, T.V. Shaftan, G.M. Wang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by DOE contract DE-AC02-98CH10886 A Matlab interface package for Elegant simulation code is under development. This package combines advantages of Elegant, which is one of the most advanced codes for accelerator simulations, with advantages of useful and effective Matlab functions for data processing, analysis, optimization, and real-time machine control using Maltab Middle Layer. A number of functions have been already developed: calculation of lattice parameters and Twiss functions, linear and high-order chromaticity, amplitude-dependent tune shifts, modification of lattice elements, correction of betatron tunes and chromaticity, a set of functions for graphic representation. These functions have been successfully used at NSLS-II for tracking and turn-by-turn simulations near the half-integer resonance, for maximizing tunability and dynamic aperture of NSLS-II Booster, and for calculating limits of top-up Booster energy interlock.
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Paper

Title

Page

High Power Radiation Sources using the Steady-state Microbunching Mechanism

1048

A. Chao, E. Granados, X. Huang, D.F. Ratner
SLAC, Menlo Park, California, USA
H.W. Luo
NTHU, Hsinchu, Taiwan

The mechanism of steady-state microbunching (SSMB) was proposed for providing high power coherent radiation using electron storage rings. The mechanism follows closely the RF bunching in conventional storage rings, except that the energy modulation of by an RF system at a microwave wavelength is replaced by a seeded laser in an undulator at an optical wavelength. No FEL mechanism, and thus no FEL energy heating, is invoked. The basic idea is firstly to make the beam microbunched so that its radiation becomes coherent, and secondly to make the microbunching a steady state so that the coherent radiation is maintained at every turn. The combination of the high repetition rate of a storage ring and the enhanced radiation power by a factor of N (the number of electrons in the microbunches within one coherence length) opens the possibility as well as challenges of very high power SSMB sources. To explore its potential reach, we apply SSMB to the infrared, deep ultraviolet and EUV regions and estimate their respective power levels using SPEAR3 as example. Several variants of the SSMB schemes are discussed. A proof-of-principle configuration without an identified testbed is also suggested.

Slides TUXB01 [1.602 MB]

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WEPMY043

Parallel Particle Movement Simulation Algorithm Based on Heterogeneous Computing

2654

L.G. Zhang, L. Cao, K. Fan, J. Huang, K.F. Liu, W. Qi, J. Yang
HUST, Wuhan, People's Republic of China

Particle in cell (PIC) algorithm studies the self-consistent motion of multi-particle system by solving equations of particle dynamics, this algorithm is widely used to evaluate the nonlinear space charge effect of the high intensity or low energy beam. In order to reduce the random noise in the simulation, a huge number of particles should be traced, the process expends many computer hardware resources and a lot of computing time. Heterogeneous computing can greatly improve the efficiency of large quantities of the particle tracking by making full use of different types of computing resources. In this paper we give the algorithm which uses both CPU and GPU to trace the particles in electromagnetic field. The results show that the given algorithm increases the efficiency significantly.

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WEPOY002

A Time Domain Analysis Method for RF Noise

2994

L. Lin, B. Du, G. Huang, Y.T. Liu
USTC/NSRL, Hefei, Anhui, People's Republic of China

A time domain analysis method is developed for the calculation of the longitudinal oscillations caused by the RF noise in the storage ring. This method is based on the impulse response model, and it could calculates the change of transient field caused by beam oscillation and RF noise turn by turn. By means of discrete spectrum analysis, the spectrum of the beam is obtained. According to this analysis method, we developed a simulation pro-gram. The synchronous oscillation of the excited by high RF source with a phase modulation is predicted in this program, and the corresponding experimental measure-ments are carried out on HLS II. The fitting results are in agreed with the experimental measurements.

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WEPOY026

Simulation and Measurement of the Beam Breakup Instability in a W-band Corrugated Structure

3044

D. Wang, C.-X. Tang
TUB, Beijing, People's Republic of China
S.P. Antipov, C.-J. Jing, J.Q. Qiu
Euclid TechLabs, LLC, Solon, Ohio, USA
M.E. Conde, D.S. Doran, W. Gai, G. Ha, W. Liu, J.G. Power, E.E. Wisniewski
ANL, Argonne, Illinois, USA

The corrugated wakefield structure has wide application in electron beam energy manipulation and high frequency RF radiation generation. The transverse wakefield which cause beam breakup (BBU) instability is excited when the drive beam is not perfectly centered through the structure. Here we report on the numerical and experimental investigation of the BBU effect in a W-band corrugated structure, for both cases of short range wakefield and long range wakefield. In the numerical part we develop a point to point (P2P) code that allows rapid and efficiency simulations of the beam dynamics effect by wakefield, which is based on the the particle-wake function coupled dynamics equation of motion. And the experimental measurements of BBU effect are found to be in good agreement with the simulations.

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WEPOY033

Space Charge Compensation in Low Energy Beam Lines

3055

SUPSS065

use link to see paper's listing under its alternate paper code

F. Gérardin, N. Chauvin, D. Uriot
CEA/IRFU, Gif-sur-Yvette, France
M.A. Baylac, D. Bondoux, F. Bouly
LPSC, Grenoble Cedex, France
A. Chancé, O. Napoly, N. Pichoff
CEA/DSM/IRFU, France

The dynamics of a high intensity beam with low energy is governed by its space-charge forces which may be responsible of emittance growth and halo formation due to their non-linearity. In a low energy beam transport (LEBT) line of a linear accelerator, the propagation of a charged beam with low energy causes the production of secondary particles created by the interaction between the beam and the background gas present in the accelerator tube. This phenomenon called space-charge compensation is difficult to characterize analitically. In order to obtain some quantitative to characterize the space-charge compensation (or neutralization), numerical simulations using a 3D PIC code have been implemented.

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WEPOY034

Latest Improvements of OPAL

3058

C.J. Metzger-Kraus, M. Abo-Bakr, B.C. Kuske
HZB, Berlin, Germany
A. Adelmann
PSI, Villigen PSI, Switzerland

OPAL (Object Oriented Parallel Accelerator Library) is an open source, C++ based tool for charged particle tracking in large accelerator structures and beam lines including 3D space charge, particle matter interaction and FFAG capabilities. The careful parallel design makes it possible to tackle large and complex problems, in a reasonable time frame. The current code status and latest program improvements and upgrades are introduced. One of the provided flavors, OPAL-T, was, so-far, used for relatively simple lattices and was not well suited for more complicated arrangements of elements. One of the major upgrades is the possibility to place elements in 3D space, giving the user a better control in absolute element positioning. The old input format with relative positioning is still supported. We show results of the BERLinPro lattice and compare it with results obtained with elegant.

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WEPOY035

Free Electron Laser Simulation Tool Based on FDTD/PIC in the Lorentz Boosted Frame

3061

A. Yahaghi, A. Fallahi, F.X. Kärtner
CFEL, Hamburg, Germany
F.X. Kärtner
MIT, Cambridge, Massachusetts, USA

Funding: Alexander von Humboldt-Foundation European Research Council(ERC)
Free Electron Lasers (FELs) are promising sources capable of generating electromagnetic waves in the whole spectrum. Therefore, it is crucial and additionally very useful to develop sophisticated though complete simulation tools. This goal is mainly motivated by our research focus on the development of compact X-ray sources based on radiation in optical undulators. The currently existing softwares are usually written to tackle special cases with particular approximations, such as 1D FEL theory, steady state, slow wave and forward wave approximation, wiggler-averaged electron motion and slices approximation. Many of the above approximations are hardly valid when sub-femtosecond bunches interact with intense optical lasers. The presented software aims the analysis of the FEL interaction without considering any of the above approximations. The developed tool apparently suffers from long computation times but offers a more accurate picture on the radiation process. In order to overcome the problem of multidimensionality, we exploit Lorentz boosted coordinate system and implement Finite Difference Time Domain (FDTD) method combined with Particle in Cell (PIC) simulation in this frame.

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WEPOY036

Progress in Automatic Software-based Optimization of Accelerator Performance

3064

S.I. Tomin, G. Geloni
XFEL. EU, Hamburg, Germany
I.V. Agapov, I. Zagorodnov
DESY, Hamburg, Germany
W.S. Colocho, T.M. Cope, A.B. Egger, D.F. Ratner
SLAC, Menlo Park, California, USA
Y.A. Fomin, Y.V. Krylov, A.G. Valentinov
NRC, Moscow, Russia

Funding: partial support from Ioffe Roentgen Institute grant EDYN EMRAD
For modern linac- and storage-ring-based light sources certain amount of empirical tuning is used to reach ultimate performance. The possibility to perform such empirical tuning by automatic methods has now been demonstrated by several authors (e.g. I.Agapov et al. in proc IPAC 2015). In this paper we present the progress in development of our automatic optimisation software based on OCELOT and its applications to SASE FEL optimization at FLASH and LCLS, and its potential for storage ring optimization.

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WEPOY037

Optimization of THz Radiation Pulses at FLUTE

3067

M. Yan, A.-S. Müller, M.J. Nasse, M. Schuh, M. Schwarz
KIT, Karlsruhe, Germany

The accelerator test facility FLUTE (Ferninfrarot Linac Und Test Experiment) will allow research and development in electron accelerator technology as well as photon science. Electron bunches of durations in the femtosecond range will be provided to generate intense THz radiation. Start-to-end simulation of the accelerator has been performed with the bunch length as the optimization objective. Based on the resulting charge distribution the expected THz field properties can be calculated. In this paper we combine the two tools and present first results.

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WEPOY038

Design of a Collection and Selection System for High Energy Laser-Driven Ion Beams

3070

F. Schillaci, G.A.P. Cirrone, G. Cuttone, D. Rifuggiato
INFN/LNS, Catania, Italy
M. Maggiore
INFN/LNL, Legnaro (PD), Italy

Laser-based accelerators are gaining interest in recent years as an alternative to conventional machines. Nowadays, energy and angular spread of the laser-driven beams are the main issues in application and different solutions for dedicated beam-transport lines have been proposed. In this context a system of permanent magnet quadrupoles has been realized, by INFN researchers in collaboration with SIGMAPHI company, to be used as a collection system for laser-driven protons up to 20 MeV. The definition of well specified characteristics, in terms of performances and field quality, of the magnetic lenses is crucial for the system realization and an accurate study of the beam dynamics. Hence, a method for studying the errors on the PMQ harmonic contents has been developed. It consists of different series of simulations in which magnetic and mechanical errors are introduced in the array and the harmonic content is analyzed to fix the tolerances necessary to have a good beam quality downstream the system. The method developed for the analysis of the PMQs errors and its validation is here described. The technique is general and can be easily extended to any magnetic lens.

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WEPOY039

GIOTTO: A Genetic Code for Demanding Beam-dynamics Optimizations

3073

A. Bacci
Istituto Nazionale di Fisica Nucleare, Milano, Italy
V. Petrillo
Universita' degli Studi di Milano, Milano, Italy
M. Rossetti Conti
Universita' degli Studi di Milano & INFN, Milano, Italy

GIOTTO is a software based on a Genetic Algorithm (GA). Its development started in 2007 with a work published on NIMB (263, 2007, 488-496) and presented at PAC07 (THPAN031). When the parameters, defining an acceleration machine beam line, are strongly correlated in nonlinear way, the GAs are a powerful tool to coup with these difficulties. These conditions are typically generated by space-charge, as in the high brightness e-beam photo-injectors or when the Velocity Bunching compression technique (VB) is used. The power of GIOTTO is the adaptability to different cases, given by its own structure that permits to drive different external codes in series, the possibility to define a user dependent multi objective fitness function and function constraints on the beam dynamics, as well as the possibility to turn off the genetic optimization to perform statistical analysis (machine jitters). Up today it has been used in Thomson/Compton sources, ultra-short e-bunches generation by VB, focusing channel and dog-leg lines optimizations.

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WEPOY040

Lattice Translation Between Accelerator Simulation Codes for Superkekb

3077

D. Zhou, H. Koiso, A. Morita, Y. Ohnishi, K. Oide, H. Sugimoto
KEK, Ibaraki, Japan
M.E. Biagini
INFN/LNF, Frascati (Roma), Italy
N. Carmignani, S.M. Liuzzo
ESRF, Grenoble, France
D. Sagan
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

To improve collaborative studies on beam dynamics for SuperKEKB between several labs, efforts have been made to translate the SAD lattices of SuperKEKB rings to the versions for other codes: AT, Bmad, MAD-X, and PTC. It turns out that lattice translations between these codes are not straightforward because of the complexity of the SuperKEKB lattices. In this paper, we describe our experiences of lattice translations, and present some results of benchmarks for the case of SuperKEKB.

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WEPOY041

Fast Tracking of Nonlinear Dynamics in the ESS Linac Simulator via Particle-Count Invariance

3080

SUPSS063

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B.T. Folsom, E. Laface
ESS, Lund, Sweden

Real-time beam modeling has been used in accelerator diagnostics for several decades. Along the way, the theory for matrix calculations of linear forces has matured, allowing for fast calculations of a beam's momentum and position distributions. This formalism becomes complicated and ultimately breaks down with high-order beam elements like sextupoles. Such elements can be accurately modeled with a Lie-algebra approach, but these techniques are generally implemented in slower, offline multiparticle tracking software. Here, we demonstrate an adaptation of the conventional Lie techniques for rapid first-order tracking of position, which is accomplished by treating a bunch's particle count as an invariant.

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WEPOY042

Open XAL Status Report 2016

3083

T.A. Pelaia II, C.K. Allen, A.P. Shishlo, A.P. Zhukov
ORNL, Oak Ridge, Tennessee, USA
D.A. Brown
NMSU, Las Cruces, New Mexico, USA
Y.-C. Chao
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
C.P. Chu, Y. Zhang
FRIB, East Lansing, Michigan, USA
P. Gillette, P. Laurent, E. Lécorché, G. Normand
GANIL, Caen, France
E. Laface, Y.I. Levinsen, M. Muñoz
ESS, Lund, Sweden
Y. Li
IHEP, Beijing, People's Republic of China
I. List, M. Pavleski
Cosylab, Ljubljana, Slovenia
X.H. Lu
CSNS, Guangdong Province, People's Republic of China

Funding: This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC0500OR22725 with the U.S. Department of Energy.
Formed in 2010, the Open XAL accelerator physics software platform was developed through an international collaboration among several facilities to establish it as a standard for accelerator physics software. While active development continues, the project has now matured. This paper presents the current status of the project, a roadmap for continued development and an overview of the project status at each participating facility.

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WEPOY044

Review of CPU and GPU Faddeeva Implementations

3090

A. Oeftiger, R. De Maria, L. Deniau, K.S.B. Li, E. McIntosh, L. Moneta
CERN, Geneva, Switzerland
A. Aviral
BITS Pilani, Pilani, India
S. Hegglin
ETH, Zurich, Switzerland
A. Oeftiger
EPFL, Lausanne, Switzerland

Funding: CERN, Doctoral Studentship EPFL, Doctorate
The Faddeeva error function is frequently used when computing electric fields generated by two-dimensional Gaussian charge distributions. Numeric evaluation of the Faddeeva function is particularly challenging since there is no single expansion that converges rapidly over the whole complex domain. Various algorithms exist, even in the recent literature there have been new proposals. The many different implementations in computer codes offer different trade-offs between speed and accuracy. We present an extensive benchmark of selected algorithms and implementations for accuracy, speed and memory footprint, both for CPU and GPU architectures.

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WEPOY045

Benchmarking the Beam Longitudinal Dynamics Code BLonD

3094

H. Timko, J.F. Esteban Müller, A. Lasheen, D. Quartullo
CERN, Geneva, Switzerland

The relatively recent Beam Longitudinal Dynamics code BLonD has already been applied to a wide range of studies for all present CERN synchrotrons. Its application area ranges from studies of RF manipulations, over single and multi-bunch interactions with impedance, to the action of feedback loops and RF noise. In this paper, we present benchmarks and comparisons with measurements, theory, or other codes, which have increased greatly the trust in the code. Tests related to bunch-to-bucket transfer, feedback loops, diffusion due to noise injection, as well as collective effects, are presented.

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WEPOY046

Beam Delivery Simulation: BDSIM - Automatic Geant4 Models of Accelerators

3098

L.J. Nevay, S.T. Boogert, L.C. Deacon, S.M. Gibson, R. Kwee-Hinzmann, W. Shields, J. Snuverink
JAI, Egham, Surrey, United Kingdom
H. Garcia
CERN, Geneva, Switzerland

Beam Delivery Simulation (BDSIM) is a program that uses a suite of high energy physics software including Geant4, CLHEP & ROOT, that seamlessly tracks particles through accelerators and detectors utilising the full range of particles and physics processes from Geant4. BDSIM has been used to simulate linear colliders such as the International Linear Collider (ILC) and more recently, circular colliders such as the Large Hadron Collider (LHC). The latest developments including improved geometry modelling; external geometry support; process biasing; and a new event display are presented. A significantly revised and improved accompanying tool chain is presented comprising of a series of Python utilities that allow efficient and automatic preparation of models. Furthermore, a library for both ROOT and Python that provides powerful analysis and event viewing after simulation is demonstrated.

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WEPOY048

Overview of the Design of the IBEX Linear Paul Trap

3104

S.L. Sheehy
JAI, Oxford, United Kingdom
D.J. Kelliher, S. Machida, D.C. Plostinar, C.R. Prior
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

We report on the status and design of the Intense Beam Experiment (IBEX) at RAL. This experiment consists of a linear Paul trap apparatus similar to the S-POD system at University of Hiroshima, confining non-neutral Argon plasma in an RF quadrupole field. The physical equivalence between this device and a beam in a linear focusing channel makes it a useful tool for accelerator physics studies including resonances and high intensity effects. We give an overview of the design and construction of IBEX and outline plans for commissioning and the future experimental programme.

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WEPOY050

A Differential Algebraic Framework for the Fast Indirect Boundary Element Method

3107

SUPSS064

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A.J. Gee, B. Erdelyi
Northern Illinois University, DeKalb, Illinois, USA
B. Erdelyi
ANL, Argonne, USA

Beam physics at the intensity frontier must account for the beams' realistic surroundings on their dynamics in an accurate and efficient manner. Mathematically, the problem can be expressed as a Poisson PDE with given boundary conditions. Commonly, the Poisson boundary value problem is solved locally within many volume elements. However, it is known the PDE may be re-expressed as indirect bound- ary integral equations (BIE) which give a global solution*. By solving the BIEs on M surface elements, we arrive at the indirect boundary element method (iBEM). Iteratively solving this dense linear system of form Ax = b scales like (m_iterations M² ). Accelerating with the fast multipole method (FMM) can reduce this to O(M) if m_iterations << M. For N evaluation points, the total complexity would be O(M) + O(N) or O(N) with N = M. We have implemented a constant element version of this fast iBEM based on our previous work with the FMM in the differential algebraic (DA) framework**. This implementation is to illustrate the flexibility and accuracy of our method. A future version will focus on allowing for higher order elements.
* Sauter, S. and C. Schwab. Boundary Element Methods (2011)
** Abeyratne, S., S. Manikonda, and B. Erdelyi. "A novel differential algebraic adaptive fast multipole method." IPAC 2013: 1055-1057.

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WEPOY051

Performance Optimization of Multi-particle Beam Dynamics Code IMPACT-Z on NVidia GPGPU

3110

Z.Q. He, G. Shen, Y. Yamazaki
FRIB, East Lansing, Michigan, USA
X. Wang
ICER, MSU, East Lansing, USA

Funding: The work is supported by the U.S. National Science Foundation , the U.S. Department of Energy Office of Science, the Institute for Cyber-Enabled Research, MSU.
Facility for Rare Isotope Beams is designed using a multiparticle tracking code IMPACT-Z. IMPACT-Z is originally for the purpose of accelerator design, so it is precise, however, quite time consuming, therefore usually not suitable for on-line beam tuning applications. IMPACT-Z is originally boosted using Message Passing Interface (MPI) technology. For single node mode, performance of IMPACT-Z is usually bounded by CPU performance, and for multimode mode, communication between MPI processes would become bottleneck. However, new emerging High Performance Computing (HPC) technology, like general-purpose graphics processing unit (GPGPU), brings new possibility in accelerating IMPACT-Z, so that the speed of IMPACT-Z satisfies for on-line beam tuning applications. This paper presents the efforts in exploring the capability of Nvidia GPGPU and the results of speed up of IMPACT-Z.

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WEPOY053

Comparison of Tracking Codes for the Determination of Dynamic Aperture in Storage Rings

3114

R. Hipple, M. Berz
MSU, East Lansing, Michigan, USA

Funding: This work is supported by the U.S. Department of Energy under grant number DE-FG02-08ER41546
Currently there is a great deal of activity towards making precision measurements utilizing storage rings, for example the Muon g-2 experiment at Fermilab, and the Electric Dipole Moment (EDM) program of the JEDI Collaboration. These experiments are intended to perform measurements requiring sub-ppm precision. Of utmost importance in this regard is the ability of tracking codes to treat all nonlinear effects arising from the detailed field distributions present in the system, not the least of which are fringe fields. In previously published work,*,**, we performed parallel tests of various tracking codes in order to compare and contrast the results. In this study, we continue this line of research and extend the scope to parallel-faced dipoles and electrostatic dipoles.
* R.Hipple, M. Berz, Microscopy and Microanalysis 21 Suppl. 4 (2015)
** R. Hipple, M.Berz, MODBC3, ICAP 2015, in press.

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WEPOY054

A Matlab Interface Package for Elegant Simulation Code

3117

V.V. Smaluk, T.V. Shaftan, G.M. Wang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by DOE contract DE-AC02-98CH10886
A Matlab interface package for Elegant simulation code is under development. This package combines advantages of Elegant, which is one of the most advanced codes for accelerator simulations, with advantages of useful and effective Matlab functions for data processing, analysis, optimization, and real-time machine control using Maltab Middle Layer. A number of functions have been already developed: calculation of lattice parameters and Twiss functions, linear and high-order chromaticity, amplitude-dependent tune shifts, modification of lattice elements, correction of betatron tunes and chromaticity, a set of functions for graphic representation. These functions have been successfully used at NSLS-II for tracking and turn-by-turn simulations near the half-integer resonance, for maximizing tunability and dynamic aperture of NSLS-II Booster, and for calculating limits of top-up Booster energy interlock.

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