Author: Faillace, L.
Paper Title Page
MOPOMS019 The New SPARC_LAB RF Photo-Injector 671
 
  • D. Alesini, M.P. Anania, M. Bellaveglia, A. Biagioni, F. Cardelli, G. Costa, M. Del Franco, G. Di Pirro, L. Faillace, M. Ferrario, G. Franzini, A. Gallo, A. Giribono, L. Piersanti, L. Sabbatini, A. Stella, A. Vannozzi
    INFN/LNF, Frascati, Italy
  • A. Battisti, E. Chiadroni, G. Di Raddo, A. Liedl, V.L. Lollo, L. Pellegrino, R. Pompili, S. Romeo, V. Shpakov, C. Vaccarezza, F. Villa
    LNF-INFN, Frascati, Italy
  • M. Carillo, E. Chiadroni
    Sapienza University of Rome, Rome, Italy
  • A. Cianchi, M. Galletti
    Università di Roma II Tor Vergata, Roma, Italy
 
  A new RF photo-injector has been designed, realized and successfully installed at the SPARC_LAB facility (INFN-LNF, Frascati, Rome). It is based on a 1.6 cell RF gun fabricated with the new brazing free technology recently developed at the National Laboratories of Frascati. The electromagnetic design has been optimized to have a full compensation of the dipole and quadrupole field components introduced by the coupling hole with an improvement of the effective pumping speed with two added pumping ports. The gun is overcoupled (\beta=2) to reduce the filling time and to allow the operation with short RF pulses. The overall injector integrates a new solenoid with a remote control of the transverse position and a variable skew quadrupole for the compensation of residual quadrupole field components. It also allows an on axis laser injection system with the last mirror in air, and the possibility of a future integration of an X/C band cavity linearizer. In the paper we report the main characteristics of the electromagnetic and mechanical design and the low and high power test results that shows the extremely good perfomances of the new device.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS019  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 26 June 2022
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MOPOMS020 Dark Current Studies for a High Gradient SW C-Band RF Gun 675
 
  • F. Cardelli, D. Alesini, L. Faillace, A. Giribono, A. Vannozzi
    INFN/LNF, Frascati, Italy
  • G. Di Raddo
    LNF-INFN, Frascati, Italy
  • T.G. Lucas
    PSI, Villigen PSI, Switzerland
 
  It is now well-established that for the generation of very high brightness beams, required for fourth generation light sources, it is highly advantageous to use injectors based on Radiofrequency photo-guns with very high peak electric fields on the cathode (>120 MV/m). This very high surface electric field leads to the generation of undesirable electrons due to the field emission effect. The emitted electrons can be captured and propagate along the Linac forming a dark current beam, leading to background radiation that can damage the instrumentation and radioactivate components. Consequently, it is important that the emission of these electrons, and their subsequent transportation, is carefully evaluated. Recently, in the framework of the I-FAST project, a high gradient, standing wave, C-band (5712 MHz) RF photogun has been designed and will be realized soon. In this paper, the results of dark current studies and simulations are illustrated. The transport efficiency and the spectrum of the dark current have been evaluated by Particle-In-Cell simulations for different cathode peak field values considering also the effect of the focusing solenoid on the dark current beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS020  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 30 June 2022
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WEPOMS017 Space Charge Analysis for Low Energy Photoinjector 2272
SUSPMF075   use link to see paper's listing under its alternate paper code  
 
  • M. Carillo, F. Bosco, E. Chiadroni, L. Giuliano, M. Migliorati, A. Mostacci, L. Palumbo
    Sapienza University of Rome, Rome, Italy
  • M. Behtouei, B. Spataro
    LNF-INFN, Frascati, Italy
  • O. Camacho, A. Fukasawa, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • L. Faillace
    INFN/LNF, Frascati, Italy
  • L. Ficcadenti
    INFN-Roma, Roma, Italy
 
  Funding: This work is supported by DARPA under Contract HR001120C0072, by DOE Contract DE-SC0009914 & DE-SC0020409, by the National Science Foundation Grant N.PHY-1549132 and by INFN through the project ARYA.
Beam dynamics studies are performed in the context of a C-Band hybrid photo-injector project developed by a collab- oration between UCLA/Sapienza/INFN-LNF/RadiaBeam. These studies aim to explain beam behaviour through the beam-slice evolution, using analytical and numerical approaches. An understanding of the emittance oscillations is obtained starting from the slice analysis, which allows correlation of the position of the emittance minima with the slope of the slices in the transverse phase space (TPS). At the end, a significant reduction in the normalized emittance is obtained by varying the transverse shape of the beam while assuming a longitudinal Gaussian distribution. Indeed, the emittance growth due to nonlinear space-charge fields has been found to occur immediately after moment of the beam emission from the cathode, giving insight into the optimum laser profile needed for minimizing the emittance.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS017  
About • Received ※ 16 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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WEPOMS045 Modeling and Mitigation of Long-Range Wakefields for Advanced Linear Colliders 2350
SUSPMF071   use link to see paper's listing under its alternate paper code  
 
  • F. Bosco, M. Carillo, L. Giuliano, M. Migliorati, A. Mostacci, L. Palumbo
    Sapienza University of Rome, Rome, Italy
  • O. Camacho, A. Fukasawa, N. Majernik, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • E. Chiadroni, B. Spataro, C. Vaccarezza
    LNF-INFN, Frascati, Italy
  • L. Faillace, A. Giribono
    INFN/LNF, Frascati, Italy
 
  Funding: This work is supported by DARPA under Contract N.HR001120C0072, by DOE Contract DE-SC0009914 and DE-SC0020409, by the National Science Foundation Grant N.PHY-1549132 and by INFN.
The luminosity requirements of TeV-class linear colliders demand use of intense charged beams at high repetition rates. Such features imply multi-bunch operation with long current trains accelerated over the km length scale. Consequently, particle beams are exposed to the mutual parasitic interaction due to the long-range wakefields excited by the leading bunches in the accelerating structures. Such perturbations to the motion induce transverse oscillations of the bunches, potentially leading to instabilities such as transverse beam break-up. Here we present a dedicated tracking code that studies the effects of long-range transverse wakefield interaction among different bunches in linear accelerators. Being described by means of an efficient matrix formalism, such effects can be included while preserving short computational times. As a reference case, we use our code to investigate the performance of a state-of-the-art linear collider currently under design and, in addition, we discuss possible mitigation techniques based on frequency detuning and damping.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS045  
About • Received ※ 20 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 10 July 2022
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MOPOMS021 The New C Band Gun for the Next Generation RF Photo-Injectors 679
 
  • D. Alesini, M. Ferrario, A. Giribono, A. Gizzi, L. Piersanti, A. Vannozzi
    INFN/LNF, Frascati, Italy
  • F. Cardelli, G. Di Raddo, L. Faillace, S. Lauciani, A. Liedl, L. Pellegrino, C. Vaccarezza
    LNF-INFN, Frascati, Italy
  • G. Castorina
    AVO-ADAM, Meyrin, Switzerland
  • M. Croia
    ENEA Casaccia, Roma, Italy
  • L. Ficcadenti
    INFN-Roma, Roma, Italy
  • G. Pedrocchi
    SBAI, Roma, Italy
 
  Funding: European Union’s Horizon 2020 Research and Innovation programme under GA No 101004730 and INFN Commission V.
RF photo-injectors are widely used in modern facilities, especially in FEL, as very low-emittance and high-brightness electron sources. Presently, the RF technology mostly used for RF guns is the S band (3 GHz) with typical cathode peak fields of 80-120 MV/m and repetition rates lower than 120 Hz. There are solid reasons to believe that the frequency step-up from S band to C band (6 GHz) can provide a strong improvement of the beam quality due to the potential higher achievable cathode field (>160 MV/m) and higher repetition rate (that can reach the kHz level). In the contest of the European I.FAST project, a new C band gun has been designed and will be realized and tested. It is a 2.5 cell standing wave cavity with a four port mode launcher, designed to operate with short RF pulses (<300 ns) and cathode peak field larger than 160 MV/m. In the paper we present the electromagnetic and thermo-mechanical design and the results of the prototyping activity and rf measurements.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS021  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 28 June 2022
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MOPOMS022 Studies of a Ka-Band High Power Klystron Amplifier at INFN-LNF 683
 
  • M. Behtouei, L. Faillace, A. Mostacci, B. Spataro
    LNF-INFN, Frascati, Italy
  • F. Bosco, M. Carillo, M. Migliorati, A. Mostacci, L. Palumbo
    Sapienza University of Rome, Rome, Italy
  • F. Di Paolo, S. Fantauzzi, A. Leggieri, F. Marrese, L. Valletti
    Università degli Studi di Roma "Tor Vergata", Roma, Italy
  • G. Torrisi
    INFN/LNS, Catania, Italy
 
  In the framework of the Compact Light XLS project, a Ka-band linearizer with electric field ranging from 100 to 150 MV/m is requested. In order to feed this structure, a proper Ka-band high power klystron amplifier with a high efficiency is needed. This paper reports a possible solution for a klystron amplifier operating on the TM010 mode at 36 GHz, the third harmonic of the 12 GHz linac frequency, with an efficiency of 44% and 10.6 MW radiofrequency output power. We discuss also here the high-power DC gun with the related magnetic focusing system, the RF beam dynamics and finally the multiphysics analysis of a high- power microwave window for a Ka-band klystron providing 16MW of peak power.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS022  
About • Received ※ 18 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 10 July 2022
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MOPOMS023 Start-to-End Beam-Dynamics Simulations of a Compact C-Band Electron Beam Source for High Spectral Brilliance Applications 687
 
  • L. Faillace, M. Behtouei, B. Spataro, C. Vaccarezza
    LNF-INFN, Frascati, Italy
  • R.B. Agustsson, I.I. Gadjev, S.V. Kutsaev, A.Y. Murokh
    RadiaBeam, Marina del Rey, California, USA
  • F. Bosco, M. Carillo, L. Giuliano, M. Migliorati, A. Mostacci, L. Palumbo
    Sapienza University of Rome, Rome, Italy
  • D.L. Bruhwiler
    RadiaSoft LLC, Boulder, Colorado, USA
  • O. Camacho, A. Fukasawa, N. Majernik, J.B. Rosenzweig, O. Williams
    UCLA, Los Angeles, California, USA
  • A. Giribono
    INFN/LNF, Frascati, Italy
  • S.G. Tantawi
    SLAC, Menlo Park, California, USA
 
  Funding: This work is partially supported by DARPA under the Contract No. HR001120C0072, by DOE Contract DE-SC0009914, DOE Contract DE-SC0020409, and by the National Science Foundation Grant No. PHY-1549132.
Proposals for new linear accelerator-based facilities are flourishing world-wide with the aim of high spectral brilliance radiation sources. Most of these accelerators are based on electron beams, with a variety of applications in industry, research and medicine such as colliders, free-electron lasers, wake-field accelerators, coherent THz and inverse Compton scattering X/’ sources as well as high-resolution diagnostics tools in biomedical science. In order to obtain high-quality electron beams in a small footprint, we present the optimization design of a C-band linear accelerator machine. Driven by a novel compact C-band hybrid photoinjector, it will yield ultra-short electron bunches of few 100’s pC directly from injection with ultra-low emittance, fraction of mm-mrad, and a few hundred fs length simultaneously, therefore satisfying full 6D emittance compensation. The normal-conducting linacs are based on a novel high-efficiency design with gradients up to 50 MV/m. The beam maximum energy can be easily adjusted in the mid-GeV’s range. In this paper, we discuss the start-to-end beam-dynamics simulations in details.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS023  
About • Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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TUPOST015 Commissioning and First Results of an X-Band LLRF System for TEX Test Facility at LNF-INFN 876
 
  • L. Piersanti, D. Alesini, M. Bellaveglia, S. Bini, B. Buonomo, F. Cardelli, C. Di Giulio, E. Di Pasquale, M. Diomede, L. Faillace, A. Falone, G. Franzini, A. Gallo, G. Giannetti, A. Liedl, D. Moriggi, S. Pioli, S. Quaglia, L. Sabbatini, M. Scampati, G. Scarselletta, A. Stella, S. Tocci, L. Zelinotti
    LNF-INFN, Frascati, Italy
 
  Funding: Latino is a project co-funded by Regione Lazio within POR-FESR 2014-2020 program
In the framework of LATINO project (Laboratory in Advanced Technologies for INnOvation) funded by Lazio regional government, the commissioning of the TEst stand for X-band (TEX) facility has started in 2021 at Frascati National Laboratories of INFN. Born as a collaboration with CERN to test high gradient accelerating structures, during 2022 TEX aims at feeding the first EuPRAXIA@SPARC_LAB X-band structure prototype. During 2021 the commissioning has been successfully carried out up to 48 MW. The power unit is driven by an X-band low level RF system, that employs a commercial S-band (2.856 GHz) Libera digital LLRF (manufactured by Instrumentation Technologies), with an up/down conversion stage and a reference generation and distribution system able to produce coherent frequencies for the American S-band and European X-band (11.994 GHz), both designed and realized at LNF. The performance of the system, with a particular focus on amplitude and phase resolution, together with klystron and driver amplifier jitter measurements, will be reviewed in this paper. Moreover, considerations on its suitability and main limitations in view of EuPRAXIA@SPARC_LAB project will be discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST015  
About • Received ※ 20 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 28 June 2022
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THPOTK054 Proposal of a VHEE Linac for FLASH Radiotherapy 2903
SUSPMF120   use link to see paper's listing under its alternate paper code  
 
  • L. Giuliano, F. Bosco, M. Carillo, D. De Arcangelis, A. De Gregorio, L. Ficcadenti, D. Francescone, G. Franciosini, M. Migliorati, A. Mostacci, L. Palumbo, V. Patera, A. Sarti
    Sapienza University of Rome, Rome, Italy
  • D. Alesini, A. Gallo, A. Vannozzi
    INFN/LNF, Frascati, Italy
  • M. Behtouei, L. Faillace, B. Spataro
    LNF-INFN, Frascati, Italy
  • M.G. Bisogni, F. Di Martino, J.H. Pensavalle
    INFN-Pisa, Pisa, Italy
  • G.A.P. Cirrone, G. Cuttone, G. Torrisi
    INFN/LNS, Catania, Italy
  • V. Favaudon, A. Patriarca
    Institut Curie - Centre de Protonthérapie d’Orsay, Orsay, France
  • S. Heinrich
    Institut Curie, Centre de Recherche, Orsay, France
 
  Translation of electron FLASH radiotherapy in clinical practice requires the use of high energy accelerators to treat deep tumours and Very High Electron Energy (VHEE) could represent a valid technique to achieve this goal. In this sce- nario, a VHEE FLASH linac is under study at the University La Sapienza of Rome (Italy) in collaboration with the Italian Institute for Nuclear Research (INFN) and the Curie Insti- tute (France). Here we present the preliminary results of a compact C-band system aiming to reach an high accelerating gradient and an high pulse current necessary to deliver high dose per pulse and ultra-high dose rate required for FLASH effect. We propose a system composed of a low energy high current injector linac followed by a modular section of high accelerating gradient structures. CST code is used to define the required LINAC’s RF parameters and beam dynamics simulations are performed using T-Step, ASTRA and GPT tracking codes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK054  
About • Received ※ 17 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 10 July 2022
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