A   B   C   D   E   F   G   H   I   K   L   M   O   P   Q   R   S   T   U   V   W    

optics

Paper Title Other Keywords Page
MOP008 Design and Performance of Optics for Multi-Energy Injector Linac injection, electron, linac, quadrupole 46
 
  • Y. Ohnishi, K. Furukawa, N. Iida, T. Kamitani, M. Kikuchi, Y. Ogawa, M. Satoh, K. Yokoyama
    KEK, Ibaraki
  Injector linac provides injection beams for four storage rings, KEKB high energy electron ring (HER), KEKB low energy positron ring (LER), PF-AR electron ring, and PF electron ring. The injection beams for these rings have different energies and intensities. Recently, a requirement of simultaneous injection among these rings arises to make a top-up injection possible. Magnetic fields of DC magnets to confine the beam to the accelerating structures can not be changed between pulse to pulse, although the beam energy can be controlled by fast rf phase shifters of klystrons. This implies that common magnetic fields of bending magnets and quadrupole magnets should be utilized to deliver beams having different characteristics. Therefore, we have designed multi-energy optics for KEKB high energy electron ring (8 GeV, 1 nC/pulse) and PF electron ring (2.5 GeV, 0.1 nC/pulse) and present a performance of the multi-energy injector linac.  
 
MOP023 Beam-Based Optics Correction for New Beam Transport Line from LINAC to Photon Factory in KEK linac, luminosity, beam-transport, quadrupole 85
 
  • N. Iida, M. Kikuchi
    KEK, Ibaraki
  The e+/e- injector LINAC in KEK usually injects into four rings which are Low Energy Ring(LER) of KEKB(3.5GeV/e+), High Energy Ring (HER) of KEKB(8.0GeV/e-), Photon Factory(PF)(2.5GeV/e-) and Advanced Ring for pulse X-rays(PF-AR)(3.0GeV/e-). While LINAC continuously injects into LER and HER alternatively every about five minutes, both of KEKB rings usually storage almost full operating currents. Time for PF or PF-AR which includes switching time had taken about 20 minutes a several times in a day. This had made luminosity at KEKB lower. In summer of 2005, a part of transport line from LINAC to PF were renewed, in which a DC bending magnet only for PF apportions electron beam from the end of LINAC to the new line. We succeeded to reduce the occupancy time for PF injection to about five minutes and there is almost no affection to KEKB luminosity. In this paper optics of the new PF beam transport line is described. In practical performance there had been leakage magnetic field from ECS magnets in KEKB(e+) beam transport line neighboring the PF line. Furthermore we measured the horizontal dispersions along the line. We describe about the magnetic shielding and the optics correction.  
 
TUP064 Adaptive Three-Dimensional RMS Envelope Simulation in the SAD Accelerator Modeling Environment space-charge, simulation, controls, background 397
 
  • C. K. Allen
    LANL, Los Alamos, New Mexico
  • K. Furukawa, M. Ikegami, K. Oide
    KEK, Ibaraki
  The capability for three-dimensional RMS envelope simulation, including space charge, has been implemented in the SAD accelerator modeling environment used at KEK. The SAD (for Strategic Accelerator Design) modeling system consists of a compiled simulation engine, an in-house scripting language SADScript, and user interface support both in Tcl/tk script and SADScript. The RMS envelope simulator is implemented primarily in the SADScript language, which much resembles the Mathematica language. The dynamics within the model are similar to that used by TRACE3D, TRANSPORT, and XAL. Specifically, the symmetric matrix of all second-order beam moments is propagated using a linear beam optics model for the beamline. However, the current simulation engine employs an adaptive space-charge algorithm which actively adjusts the solution integration to maintain a specified accuracy, as well as imposing the symplectic condition. It is designed to keep the integration step size as large as possible while enforcing that the residual solution error remain below a given tolerance. The paper concentrates primarily on the adaptive nature of the RMS simulation, since this is the novel feature.  
 
TUP080 Tuning the Magnetic Transport of an Induction Linac Using Emittance emittance, simulation, background, diagnostics 444
 
  • T. L. Houck, C. G. Brown, M. M. Ong, A. Paul, J. M. Zentler
    LLNL, Livermore, California
  • P. E. Wargo
    Bechtel Nevada, Los Alamos, New Mexico
  The Lawrence Livermore National Laboratory Flash X-Ray (FXR) machine is a linear induction accelerator used to produce a nominal 20-MeV, 3-kA, 60-ns pulse width electron beam for hydrodynamic radiographs. A common figure of merit for this type of radiographic machine is the x-ray dose divided by the spot area on the bremsstrahlung converter. Several characteristics of the beam affect the minimum attainable x-ray spot size. The most significant are emittance, chromatic aberration, and beam motion. FXR is in the midst of a multi-year optimization project to reduce the spot size. This paper describes the effort to reduce beam emittance by adjusting the fields of the transport solenoids. If the magnetic transport is not correct, the beam will be mismatched and undergo envelop oscillations increasing the emittance. We measure the divergence and radius of the beam in a drift section after the accelerator by imaging the optical transition radiation (OTR) and beam envelope on a foil. These measurements are combined with transport simulations to calculate an emittance. Relative changes in the emittance can be quickly estimated allowing for an efficient, real-time study.  
 
TH3002 Normal-Conducting Energy Recuperator emittance, electron, linac, free-electron-laser 554
 
  • A. N. Matveenko, N. Vinokurov
    BINP SB RAS, Novosibirsk
  Energy recovery linacs (ERLs) for different applications were discussed intensively at last decade. The normal conducting RF ERLs offer the possibility to provide high average currents at relatively low beam energies and long electron bunches. The comparison of normal conducting and superconducting RF is described briefly. To illustrate some interesting features of normal conducting ERLs some details of design, operational experience and prospects of the Novosibirsk FEL ERL are presented.