Author: Torrisi, G.
Paper Title Page
MOPAB270 Beam Dynamics Studies in a Standing Wave Ka-band Linearizer 857
 
  • J. Scifo, M. Behtouei, L. Faillace, M. Ferrario, A. Giribono, B. Spataro, C. Vaccarezza
    INFN/LNF, Frascati, Italy
  • M. Migliorati
    INFN-Roma1, Rome, Italy
  • M. Migliorati
    Sapienza University of Rome, Rome, Italy
  • G. Torrisi
    INFN/LNS, Catania, Italy
 
  Next-generation FEL user facilities require high-quality electron beams with kA peak current. The combination of a high brightness RF injector and a magnetic compression stage represents a very performant solution in terms of electron beam emittance and peak current. One of the important issues is the design of a proper device that acts as a linearizer for the beam longitudinal phase space. Recently, the design of a SW Ka band RF accelerating structure has been proposed with promising results. The paper reports on electron beam dynamics studies in the described RF structure.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB270  
About • paper received ※ 19 May 2021       paper accepted ※ 29 August 2021       issue date ※ 26 August 2021  
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MOPAB353 Design of a compact Ka-Band Mode Launcher for High-gradient Accelerators 1100
 
  • G. Torrisi, G.S. Mauro, G. Sorbello
    INFN/LNS, Catania, Italy
  • M. Behtouei, L. Faillace, B. Spataro, A. Variola
    INFN/LNF, Frascati, Italy
  • V.A. Dolgashev
    SLAC, Menlo Park, California, USA
  • L. Faillace, M. Migliorati
    Sapienza University of Rome, Rome, Italy
  • M. Migliorati
    INFN-Roma1, Rome, Italy
  • J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • G. Sorbello
    University of Catania, Catania, Italy
 
  In this work, we present the RF design of a table-top Ka-Band mode launcher operating at 35.98 GHz. The structure consists of a symmetrical 4-port WR28 rectangular-TE10-to-circular-TM01 mode converter that is used to couple a peak output RF power of 5 MW (pulse length up to 50 ns and repetition rate up to 100 Hz) in Ka-Band linear accelerator able to achieve very high accelerating gradients (up to 200 MV/m). Numerical simulations have been carried out with the 3D full-wave commercial simulator Ansys HFSS in order to obtain a preliminary tuning of the accelerating field flatness at the operating frequency f0=35.98 GHz. The main RF parameters, such as reflection coefficient, transmission losses, and conversion efficiency are given together with a verification of the field azimuthal symmetry which avoids dipole and quadrupole deflecting modes. To simplify future manufacturing, reduce fabrication costs, and also reduce the probability of RF breakdown, the proposed new geometry has "open" configuration. This geometry eliminates the flow of RF currents through critical joints and allows this device to be milled from metal blocks.  
poster icon Poster MOPAB353 [3.131 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB353  
About • paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 27 August 2021  
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MOPAB410 Preliminary Studies of a Compact VHEE Linear Accelerator System for FLASH Radiotherapy 1229
 
  • L. Giuliano, F. Bosco, M. Carillo, D. De Arcangelis, L. Faillace, L. Ficcadenti, M. Migliorati, A. Mostacci, L. Palumbo
    Sapienza University of Rome, Rome, Italy
  • D. Alesini, M. Behtouei, B. Spataro
    INFN/LNF, Frascati, Italy
  • G. Cuttone, G. Torrisi
    INFN/LNS, Catania, Italy
  • V. Favaudon, S. Heinrich, A. Patriarca
    Institut Curie - Centre de Protonthérapie d’Orsay, Orsay, France
 
  Funding: The work is supported by La Sapienza University, research grant "grandi progetti di ricerca 2020".
The Flash Radio Therapy is a revolutionary new technique in the cancer cure: it spares healthy tissue from the damage of the ionizing radiation maintaining the tumor control as efficient as in conventional radiotherapy. To allow the implementation of the FLASH Therapy concept into actual clinical use, it is necessary to have a linear accelerator able to deliver the very high dose and very high dose rate (>106 Gy/s) in a very short irradiation time (beam on time < 100ms). Low energy S-band Linacs (up to 7 MeV) are being used in Radiobiology and pre-clinic applications but in order to treat deep tumors, the energy of the electrons should achieve the range of 60-100 MeV. In this paper, we address the main issues in the design of a compact C band (5.712 GHz) electron linac-VHEE for FLASH Radio Therapy. We present preliminary studies on C-band structures at La Sapienza and at INFN-LNS, aiming to reach a high accelerating gradient and high current necessary to deliver a dose >1 Gy/pulse, with very short electron pulse.
 
poster icon Poster MOPAB410 [0.650 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB410  
About • paper received ※ 19 May 2021       paper accepted ※ 09 June 2021       issue date ※ 21 August 2021  
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TUPAB246 Numerical Simulation and Beam-Dynamics Study of a Hollow-Core Woodpile Coupler for Dielectric Laser Accelerators 2022
 
  • G.S. Mauro, D. Mascali, G. Sorbello, G. Torrisi
    INFN/LNS, Catania, Italy
  • A. Bacci
    INFN/LASA, Segrate (MI), Italy
  • C. De Angelis, A. Locatelli
    University of Brescia, Brescia, Italy
  • A.R. Rossi
    INFN-Milano, Milano, Italy
  • G. Sorbello
    University of Catania, Catania, Italy
 
  Hollow core dielectric microstructures powered by lasers represent a new and promising area of accelerator research thanks to the higher damage threshold and accelerating gradients with respect to metals at optical wavelengths. In this paper we present the design of a dielectric Electromagnetic Band Gap (EBG) mode converter for high-power coupling of the accelerating mode in Dielectric Laser Accelerators (DLAs). The design is wavelength-independent, and here we propose an implementation operating at 90.505 GHz (wavelength 3.3 mm) based on a silicon woodpile structure. The coupler is composed by two perpendicularly coupled hollow-core waveguides: a TE-like mode waveguide (excited from RF/laser power) and a TM-like mode accelerating waveguide. The structure has been numerically designed and optimized, presenting Insertion Losses (IL) < 0.3 dB and an efficient mode conversion in the operating bandwidth. The properties and effectiveness of the confined accelerating mode have been optimized in order to derive the needed accelerating gradient. The simulated electric field has been used as input for Astra beam-dynamics simulations in order to compute the beam properties.  
poster icon Poster TUPAB246 [2.209 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB246  
About • paper received ※ 18 May 2021       paper accepted ※ 27 July 2021       issue date ※ 13 August 2021  
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