Author: Gadjev, I.I.
Paper Title Page
MOPAB139 High Resolution Imaging Design Using Permanent Magnet Quadrupoles at BNL UEM 485
 
  • G. Andonian, T.J. Campese, I.I. Gadjev, M. Ruelas
    RadiaBeam, Santa Monica, California, USA
  • M.G. Fedurin, K. Kusche, X. Yang, Y. Zhu
    BNL, Upton, New York, USA
  • C.C. Hall
    RadiaSoft LLC, Boulder, Colorado, USA
 
  Ultrafast electron microscopy techniques have demonstrated the potential to reach very high combined spatio-temporal resolution. In order to achieve high resolution, strong focusing magnets must be used as the objective and projector lenses. In this paper, we discuss the design and development of a high-resolution objective lens for use in the BNL UEM. The objective lens is a quintuplet array of permanent magnet quadrupoles, which in sum, provide symmetric focusing, high magnification, and control of higher order aberration terms. The application and design for a proof-of-concept experiment using a calibrated slit for imaging are presented. The image resolution is monitored as a function of beam parameters (energy, energy spread, charge, bunch length, spot size), and quintuplet lens parameters (drifts between lenses).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB139  
About • paper received ※ 26 May 2021       paper accepted ※ 28 May 2021       issue date ※ 18 August 2021  
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WEPAB051 Beam Dynamics for a High Field C-Band Hybrid Photoinjector 2714
 
  • L. Faillace, F. Bosco, M. Carillo, L. Giuliano, M. Migliorati, A. Mostacci, L. Palumbo
    Sapienza University of Rome, Rome, Italy
  • R.B. Agustsson, I.I. Gadjev, S.V. Kutsaev, A.Y. Murokh
    RadiaBeam, Santa Monica, California, USA
  • M. Behtouei, A. Giribono, B. Spataro, C. Vaccarezza
    INFN/LNF, Frascati, Italy
  • A. Fukasawa, N. Majernik, J.B. Rosenzweig, O. Williams
    UCLA, Los Angeles, California, USA
  • S.G. Tantawi
    SLAC, Menlo Park, California, USA
 
  Funding: This work supported by DARPA GRIT under contract no. 20204571 and partially by INFN National Committee V through the ARYA project.
In this paper, we present a new class of a hybrid photoinjector in C-Band. This project is the effort result of a UCLA/Sapienza/INFN-LNF/SLAC/RadiaBeam collaboration. This device is an integrated structure consisting of an initial standing-wave 2.5-cell gun connected to a traveling-wave section at the input coupler. Such a scheme nearly avoids power reflection back to the klystron, removing the need for a high-power circulator. It also introduces strong velocity bunching due to a 90° phase shift in the accelerating field. A relatively high cathode electric field of 120 MV/m produces a ~4 MeV beam with ~20 MW input RF power in a small foot-print. The beam transverse dynamics are controlled with a ~0.27 T focusing solenoid. We show the simulation results of the RF/magnetic design and the optimized beam dynamics that shows 6D phase space compensation at 250 pC. Proper beam shaping at the cathode yields a ~0.5 mm-mrad transverse emittance. A beam waist occurs simultaneously with a longitudinal focus of <400 fs rms and peak current >600 A. We discuss application of this injector to an Inverse-Compton Scattering system and present corresponding start-to-end beam dynamics simulations.
 
poster icon Poster WEPAB051 [0.827 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB051  
About • paper received ※ 18 May 2021       paper accepted ※ 01 July 2021       issue date ※ 15 August 2021  
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THPAB230 Design of Split Permanent Magnet Quadrupoles for Small Aperture Implementation 4247
 
  • I.I. Gadjev, G. Andonian, T.J. Campese, M. Ruelas
    RadiaBeam, Santa Monica, California, USA
  • C.C. Hall
    RadiaSoft LLC, Boulder, Colorado, USA
 
  Permanent magnet quadrupoles are ideal for strong focusing in compact footprints. Recent research in the use of permanent magnet based quadrupole magnets has enabled very high-gradient uses approaching 800T/m in final focus systems. However, in order to achieve high quality field profiles with strong fields, small diameter bore magnets must be used necessitating in vacuum operation, or very small beampipes. For small beampipe geometry, we have developed a hybrid-permanent magnet quadrupole, with steel and permanent magnet wedges, that is able to maintain high quality fields but also readily machinable in a separable design. The split design allows for accurate and reproducible reconfiguration on a beam pipe. In this paper, we will discuss the design, engineering, fabrication and first measurements of the split permanent magnet quadrupole.  
poster icon Poster THPAB230 [1.605 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB230  
About • paper received ※ 15 May 2021       paper accepted ※ 08 July 2021       issue date ※ 30 August 2021  
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