Keyword: space-charge
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MOSBC2 Linac Beam Dynamics Simulations with PyORBIT linac, simulation, lattice, cavity 20
 
  • A.P. Shishlo
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract No. DE-AC05-00OR22725
Linac dynamics simulation capabilities of the PyORBIT code are discussed. The PyORBIT is an open source and a further development of the original ORBIT code that was developed and used for design, studies, and commissioning of the SNS ring. The PyORBIT code like the original one has a two layers structure. The C++ is used to perform time consuming computations, and a program flow is controlled from the Python language shell. The flexible structure allowed using the PyORBIT also for linac dynamics simulations. The benchmark of the PyORBIT with Parmila and the XAL Online model is presented.
 
slides icon Slides MOSBC2 [1.857 MB]  
 
MOSCC1 Beam Dynamics Study concerning SIS-100 Proton Operation including Space Charge Effects lattice, dynamic-aperture, proton, ion 34
 
  • S. Sorge
    GSI, Darmstadt, Germany
 
  The projected SIS-100 synchrotron at GSI will be used for operation with intense proton and heavy ion beams. In order to avoid the crossing of the transition energy during proton operation a complicated optics scheme is proposed to provide a transition energy above the extraction energy of E=29 GeV. For the purpose of optimizing the lattice, and to find a suitable working point, regime simulation scans of the dynamic aperture are performed based on MAD-X tracking. In the next step working point candidates will be used for particle tracking simulations in order to estimate beam loss due to space charge induced resonance crossing. For these studies different codes and space charge models are considered.  
slides icon Slides MOSCC1 [0.643 MB]  
 
MOSCC2 Simulation of Space Effects During Multiturn Injection into the GSI SIS18 Synchrotron injection, simulation, emittance, septum 37
 
  • S. Appel
    GSI, Darmstadt, Germany
  • O. Boine-Frankenheim
    TEMF, TU Darmstadt, Darmstadt, Germany
 
  The optimization of the Multiturn Injection (MTI) from the UNILAC into the SIS18 is crucial in order to reach the FAIR beam intensities required for heavy ions. In order to achieve the design intensities, the efficiency of the multiturn injection from the UNILAC has to be optimized for high beam currents. We developed a simulation model for the MTI including the closed orbit bump, lattice errors, the parameters of the injected UNILAC beam, the position of the septum and other aperture limiting components, and finally the space charge force and other high-intensity effects. The model is also used to estimate the required proton and heavy-ion beam emittances from the UNILAC and from the projected p-linac. For the accurate prediction of the MTI efficiency a careful validation of the simulation model is necessary. We will present first results of the comparison between experiments and simulation for low and high uranium beam currents.  
slides icon Slides MOSCC2 [2.511 MB]  
 
MOADC3 An Application of the Non-conforming Crouzeix-Raviart Finite Element Method to Space Charge Calculations vacuum, electron 51
 
  • C.R. Bahls, U. van Rienen
    Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
 
  The calculation of space charge effects in linear accellerators is an important prerequisite to understand the interaction between charged particles and the surrounding environment. These calculations should be as efficient as possible. In this work we explore the suitability of the Crouzeix-Raviart Finite Element Method for the computation of the self-field of an electron bunch.  
slides icon Slides MOADC3 [1.028 MB]  
 
WESAI2 Space Charge and Electron Cloud Simulations electron, resonance, simulation, proton 130
 
  • G. Franchetti
    GSI, Darmstadt, Germany
  • F. Zimmermann
    CERN, Geneva, Switzerland
 
  Funding: AccNet
Tracking of high intensity effects for few turns of a circular accelerator is at reach of present computational capabilities. The situation is very different when the prediction of beam behaviour is extended to hundred of thousands of turns, where special approaches for the control of computer artifact are necessary sometimes to the expense of a complete physical modeling. The identification of the key physical ingredients helps to the development of computer algorithms capable of treating the long term tracking. In this talk it is presented the actual state of simulations for long term tracking of high intensity bunches of the SIS100 addressing the self consistent treatment of beam loss. A more realistic modeling of the incoherent effect of electron cloud is addressed as well.
 
slides icon Slides WESAI2 [7.523 MB]  
 
WEP16 Analytical Presentation of Space Charge Forces controls, beam-transport, focusing, optics 173
 
  • S.N. Andrianov
    St. Petersburg State University, St. Petersburg, Russia
 
  Funding: The work is supported by Federal Targeted Programme "Scientific and Scientific-Pedagogical Personnel of the Innovative Russia in 2009-2013" (Governmental Contract no. p 793)
This paper presents an analytical description of the space charge forces generated by charged particle beams. The suggested approach is based on some set of models for particle distribution function. All necessary calculations have analytical and closed form for different models for beam density distributions. These model distributions can be used for approximation of real beam distributions. The corresponding solutions are included in a general scheme of beam dynamics presentation based on the matrix formalism for Lie algebraic tools. The corresponding computer software is based on corresponding symbolic codes and some parallel technologies. In particular, as computational tools we consider GPU graphic card NVIDIA. As an example, there is considered the problem of modeling the beam dynamics for microprobe focusing systems.
 
 
WEACC2 Space Charge Effects and Focusing Methods for Laser Accelerated Ion Beams solenoid, simulation, focusing, laser 184
 
  • P. Schmidt, O. Boine-Frankenheim, V. Kornilov, P. Spädtke
    GSI, Darmstadt, Germany
 
  Funding: GSI Helmholtzzentrum für Schwerionenforschung Planckstr. 1 D-64291 Darmstadt
We employ the 3D PIC simulation code VORPAL to study the transport of laser accelerated proton beams in the framework of the LIGHT project at GSI. Initially the beam is assumed to be neutralized by co-moving electrons. For different initial beam distribution models we study the effect of space charge after the electrons have been removed. The results of the simulations are compared to an envelope model. We derive conditions in terms of the beam parameters and the distance from the production target for a safe removal of the electrons. As an option for the controlled de-neutralization of the beam a thin metallic foil is studied. Besides space charge, we also account for the effect of secondary electrons generated from the foil.
 
slides icon Slides WEACC2 [0.993 MB]  
 
WESCI2 Numerical Calculation of Beam Coupling Impedances in the Frequency Domain using FIT impedance, kicker, coupling, simulation 193
 
  • U. Niedermayer, O. Boine-Frankenheim
    TEMF, TU Darmstadt, Darmstadt, Germany
 
  The transverse impedance of kicker magnets is considered to be one of the main beam instability sources in the projected SIS-100 at FAIR and also in the SPS at CERN. The longitudinal impedance can contribute to the heat load, which is especially a concern in the cold sections of SIS-100 and LHC. In the high frequency range, commercially available time domain codes like CST Particle Studio® serve to calculate the impedance but they become inapplicable at medium and low frequencies which become more important for larger size synchrotrons. We present the ongoing work of developing a Finite Integration (FIT) solver in frequency domain which is based on the Parallel and Extensible Toolkit for Scientific computing (PETSc) framework in C++. Pre- and post-processing are done in MATLAB®. Infinite beam pipe boundary conditions are used. The code is applied to an inductive insert used to compensate the longitudinal space charge impedance in low energy machines. Another application focuses on the impedance contribution of a ferrite kicker with inductively coupled pulse forming network (PFN) and frequency dependent complex material permeability.  
slides icon Slides WESCI2 [3.468 MB]  
 
THP13 Emission Studies of Photocathode RF Gun at PITZ gun, electron, cathode, simulation 242
 
  • J. Li, G. Asova, M. Groß, L. Hakobyan, I.I. Isaev, Ye. Ivanisenko, M. Khojoyan, G. Klemz, G. Kourkafas, M. Krasilnikov, K. Kusoljariyakul, M. Mahgoub, D. Malyutin, B. Marchetti, A. Oppelt, B. Petrosyan, S. Rimjaem, A. Shapovalov, F. Stephan, G. Vashchenko
    DESY Zeuthen, Zeuthen, Germany
  • G. Feng
    DESY, Hamburg, Germany
  • D. Richter
    HZB, Berlin, Germany
  • L. Shang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  The Photo Injector Test facility at DESY, Zeuthen site (PITZ), was built to develop and optimize electron sources for linac based Free Electron Lasers(FELs) like FLASH and the European XFEL. For the value of the bunch charge extracted from a photocathode, discrepancy has been observed between the data measured at PITZ and simulation results from the ASTRA code. As a factor which could explain the discrepancy, a Schottky-like effect is considered. Meanwhile, the Parmela code was applied to the emission studies on the PITZ gun as benchmark. Since Parmela cannot be used to simulate a Schottky-like effect with its own modules, MATLAB scripts have been developed to implement this feature of the photoemission in an RF gun.  
 
THSCC2 Reconstruction of Velocity Field controls, electron, induction, electromagnetic-fields 256
 
  • D.A. Ovsyannikov, E.D. Kotina
    St. Petersburg State University, St. Petersburg, Russia
 
  In this paper we suppose that the distribution density of particles in phase space is known. Using Liouville’s equations the problem of finding velocity field is considered as a minimization problem. Thus the problem of determination of velocity field is reduced to solving of elliptic system of Euler-Lagrange equations.  
slides icon Slides THSCC2 [8.701 MB]  
 
FRABI1 Independent Component Analysis (ICA) Applied to Long Bunch Beams in the Los Alamos Proton Storage Ring betatron, injection, linac, extraction 294
 
  • J.S. Kolski, R.J. Macek, R.C. McCrady, X. Pang
    LANL, Los Alamos, New Mexico, USA
 
  Independent component analysis (ICA) is a powerful blind source separation (BSS) method. Compared to the typical BSS method, principal component analysis (PCA), which is the BSS foundation of the well known model independent analysis (MIA), ICA is more robust to noise, coupling, and nonlinearity. ICA of turn-by-turn beam position data has been used to measure the transverse betatron phase and amplitude functions, dispersion function, linear coupling, sextupole strength, and nonlinear beam dynamics. We apply ICA in a new way to slices along the bunch, discuss the source signals identified as betatron motion and longitudinal beam structure, and for betatron motion, compare the results of ICA and PCA.  
slides icon Slides FRABI1 [8.062 MB]