Author: Mostacci, A.
Paper Title Page
THYB01 Advanced Beam Manipulation Techniques at SPARC 2877
 
  • A. Mostacci, D. Alesini, P. Antici, A. Bacci, M. Bellaveglia, R. Boni, M. Castellano, E. Chiadroni, G. Di Pirro, A. Drago, M. Ferrario, A. Gallo, G. Gatti, A. Ghigo, E. Pace, A.R. Rossi, B. Spataro, C. Vaccarezza
    INFN/LNF, Frascati (Roma), Italy
  • A. Cianchi
    Università di Roma II Tor Vergata, Roma, Italy
  • B. Marchetti
    INFN-Roma II, Roma, Italy
  • M. Migliorati
    University of Rome "La Sapienza", Rome, Italy
  • L. Palumbo
    Rome University La Sapienza, Roma, Italy
  • V. Petrillo, L. Serafini
    Istituto Nazionale di Fisica Nucleare, Milano, Italy
  • C. Ronsivalle
    ENEA C.R. Frascati, Frascati (Roma), Italy
  
  SPARC in Fras­cati is a high bright­ness pho­to-in­jec­tor used to drive Free Elec­tron Laser ex­per­i­ments and ex­plore ad­vanced beam ma­nip­u­la­tion tech­niques. The R&D ef­fort made for the op­ti­miza­tion of the beam pa­ram­e­ters will be pre­sent­ed here, to­geth­er with the major ex­per­i­men­tal re­sults achieved. In par­tic­u­lar, we will focus on the gen­er­a­tion of sub-pi­cosec­ond, high bright­ness elec­tron bunch trains via ve­loc­i­ty bunch­ing tech­nique (the so called comb beam). Such bunch trains can be used to drive tun­able and nar­row band THz sources, FELs and plas­ma wake field ac­cel­er­a­tors.  
slides icon Slides THYB01 [20.772 MB]  
 
THPC100 Full Temporal Reconstruction using an Advanced Longitudinal Diagnostic at the SPARC FEL 3119
 
  • G. Marcus, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • M. Artioli, F. Ciocci, L. Giannessi, A. Petralia, M. Quattromini, V. Surrenti
    ENEA C.R. Frascati, Frascati (Roma), Italy
  • A. Bacci, M. Bellaveglia, E. Chiadroni, G. Di Pirro, M. Ferrario, G. Gatti, A. Mostacci, A.R. Rossi
    INFN/LNF, Frascati (Roma), Italy
  • A. Cianchi
    INFN-Roma II, Roma, Italy
  • V. Petrillo
    Istituto Nazionale di Fisica Nucleare, Milano, Italy
  • J.V. Rau
    ISM-CNR, Rome, Italy
  
  The Pro­duc­tion of ul­tra-short (sub 100 fs) sin­gle-spike ra­di­a­tion pos­sess­ing full lon­gi­tu­di­nal co­her­ence from a free-elec­tron laser (FEL) has been the sub­ject of in­tense study. A Fre­quen­cy-Re­solved Op­ti­cal Gat­ing (FROG) di­ag­nos­tic has been de­vel­oped and test­ed at UCLA, which has the ca­pa­bil­i­ty of pro­vid­ing a lon­gi­tu­di­nal re­con­struc­tion of these ul­tra-fast puls­es. This paper re­ports the re­sults of the ap­pli­ca­tion of the di­ag­nos­tic at the SPARC FEL fa­cil­i­ty.  
 
THPC159 Factory Acceptance Test of COLDDIAG: A Cold Vacuum Chamber for Diagnostics 3263
 
  • S. Gerstl, T. Baumbach, S. Casalbuoni, A.W. Grau, M. Hagelstein, T. Holubek, D. Saez de Jauregui
    Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
  • V. Baglin
    CERN, Geneva, Switzerland
  • C. Boffo, G. Sikler
    BNG, Würzburg, Germany
  • T.W. Bradshaw
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • R. Cimino, M. Commisso, A. Mostacci, B. Spataro
    INFN/LNF, Frascati (Roma), Italy
  • J.A. Clarke, R.M. Jones, D.J. Scott
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • M.P. Cox, J.C. Schouten
    Diamond, Oxfordshire, United Kingdom
  • I.R.R. Shinton
    UMAN, Manchester, United Kingdom
  • E.J. Wallén
    MAX-lab, Lund, Sweden
  • R. Weigel
    Max-Planck Institute for Metal Research, Stuttgart, Germany
  
  Su­per­con­duc­tive in­ser­tion de­vices (IDs) have high­er fields for a given gap and pe­ri­od length com­pared with the state-of-the-art tech­nol­o­gy of per­ma­nent mag­net IDs. One of the still open is­sues for the de­vel­op­ment of su­per­con­duc­tive in­ser­tion de­vices is the un­der­stand­ing of the heat in­take from the elec­tron beam. With the aim of mea­sur­ing the beam heat load to a cold bore and the hope to gain a deep­er un­der­stand­ing in the un­der­ly­ing mech­a­nisms, a cold vac­u­um cham­ber for di­ag­nos­tics was built. It is equipped with the fol­low­ing in­stru­men­ta­tion: re­tard­ing field an­a­lyz­ers to mea­sure the elec­tron flux, tem­per­a­ture sen­sors to mea­sure the beam heat load, pres­sure gauges, and mass spec­trom­e­ters to mea­sure the gas con­tent. The flex­i­bil­i­ty of the en­gi­neer­ing de­sign will allow the in­stal­la­tion of the cryo­stat in dif­fer­ent syn­chrotron light sources. The in­stal­la­tion in the stor­age ring of the Di­a­mond Light Source is fore­seen in Novem­ber 2011. Here we re­port about the tech­ni­cal de­sign of this de­vice, the fac­to­ry ac­cep­tance test and the planned mea­sure­ments with elec­tron beam.  
 
MOPC013 Design, Fabrication and High Power RF Test of a C-band Accelerating Structure for Feasibility Study of the SPARC Photo-injector Energy Upgrade 89
 
  • D. Alesini, R. Boni, G. Di Pirro, R. D. Di Raddo, M. Ferrario, A. Gallo, V.L. Lollo, F. Marcellini
    INFN/LNF, Frascati (Roma), Italy
  • G. Campogiani, A. Mostacci, L. Palumbo, S. Persichelli, V. Spizzo
    Rome University La Sapienza, Roma, Italy
  • T. Higo, K. Kakihara, S. Matsumoto
    KEK, Ibaraki, Japan
  • S. Verdú-Andrés
    TERA, Novara, Italy
  
  The en­er­gy up­grade of the SPARC pho­to-in­jec­tor from 170 to 250 MeV will be done by re­plac­ing a low gra­di­ent 3m S-Band struc­ture with two 1.5m high gra­di­ent C-band struc­tures. The struc­tures are trav­el­ing wave, con­stant impedance sec­tions, have sym­met­ric waveg­uide input cou­plers and have been op­ti­mized to work with a SLED RF input pulse. A pro­to­type with a re­duced num­ber of cells has been fab­ri­cat­ed and test­ed at high power in KEK (Japan) giv­ing very good per­for­mances in terms of break­down rates at high ac­cel­er­at­ing gra­di­ent (>50 MV/m). The paper il­lus­trates the de­sign cri­te­ria of the struc­tures, the fab­ri­ca­tion pro­ce­dure and the high power RF test re­sults.  
 
MOPS073 Impedance Calculation for Simple Models of Kickers in the Non-ultrarelativistic Regime 772
 
  • N. Biancacci, N. Mounet, E. Métral, B. Salvant, C. Zannini
    CERN, Geneva, Switzerland
  • N. Biancacci, M. Migliorati, A. Mostacci, L. Palumbo
    Rome University La Sapienza, Roma, Italy
  • Q. Qin, N. Wang
    IHEP Beijing, Beijing, People's Republic of China
  
  Kick­er mag­nets are usu­al­ly sig­nif­i­cant con­trib­u­tors to the beam cou­pling impedance of par­ti­cle ac­cel­er­a­tors. An ac­cu­rate un­der­stand­ing of their impedance is re­quired in order to cor­rect­ly as­sess the ma­chine in­ten­si­ty lim­i­ta­tions. The field match­ing method de­rived by H. Tsut­sui for the lon­gi­tu­di­nal and trans­verse dipo­lar (driv­ing) impedance of sim­ple mod­els of kick­ers in the ul­tra­rel­a­tivis­tic regime was al­ready ex­tend­ed to the non-ul­tra­rel­a­tivis­tic case, and to the quadrupo­lar (de­tun­ing) impedance in the ul­tra­rel­a­tivis­tic case. This con­tri­bu­tion pre­sents the ex­ten­sion to the quadrupo­lar impedance in the non-ul­tra­rel­a­tivis­tic case, as well as bench­marks with other avail­able meth­ods to com­pute the impedance. In par­tic­u­lar, all the com­po­nents of the impedances are bench­marked with Tsut­sui's model, i.e. in the ul­tra­rel­a­tivis­tic limit, with the model for a flat cham­ber impedance re­cent­ly com­put­ed by N. Mounet and E. Métral, in the case of fi­nite rel­a­tivis­tic gamma, and with CST Par­ti­cle Stu­dio sim­u­la­tions.  
 
WEPC107 Development of a Steady State Simulation Code for Klystron Amplifiers 2265
 
  • C. Marrelli
    CERN, Geneva, Switzerland
  • M. Migliorati, A. Mostacci, L. Palumbo
    Rome University La Sapienza, Roma, Italy
  • B. Spataro
    INFN/LNF, Frascati (Roma), Italy
  • S.G. Tantawi
    SLAC, Menlo Park, California, USA
  
  The de­sign of klystrons is based on the in­ten­sive uti­liza­tion of sim­u­la­tion codes, which can eval­u­ate the com­plete beam-cav­i­ties in­ter­ac­tion in the case of large sig­nals. In the pre­sent work, we pre­sent the de­vel­op­ment of a 2-D steady state sim­u­la­tion code that can self-con­sis­tent­ly eval­u­ate the ef­fects of the elec­tro­mag­net­ic field on the par­ti­cles and of the par­ti­cles back on the field. The al­go­rithm is based on the it­er­a­tive so­lu­tion of the power bal­ance equa­tion in the RF struc­tures and al­lows de­ter­min­ing the am­pli­tude and phase of the elec­tro­mag­net­ic field start­ing from the cav­i­ty modes. Some ap­pli­ca­tions of the code to a sin­gle cav­i­ty and a two cav­i­ty klystron are pre­sent­ed and com­pared with the re­sults ob­tained from other codes. The ef­fect of the space charge forces in the klystron drift tubes is also eval­u­at­ed.  
 
TUPO008 Electron Linac Optimization for Driving Bright Gamma-ray Sources based on Compton Back-scattering 1461
 
  • L. Serafini, F. Broggi, C. De Martinis, D. Giove
    Istituto Nazionale di Fisica Nucleare, Milano, Italy
  • D. Alesini, P. Antici, A. Bacci, M. Bellaveglia, R. Boni, E. Chiadroni, G. Di Pirro, A. Esposito, M. Ferrario, A. Gallo, G. Gatti, A. Ghigo, E. Pace, A.R. Rossi, B. Spataro, P. Tomassini, C. Vaccarezza
    INFN/LNF, Frascati (Roma), Italy
  • A. Cianchi
    Università di Roma II Tor Vergata, Roma, Italy
  • C. Maroli, V. Petrillo
    Universita' degli Studi di Milano, Milano, Italy
  • M. Migliorati, A. Mostacci, L. Palumbo
    Rome University La Sapienza, Roma, Italy
  
  We study the op­ti­mal lay-out and RF fre­quen­cy for a room tem­per­a­ture GeV-class Elec­tron Linac aim­ing at pro­duc­ing elec­tron beams that en­hance gam­ma-ray sources based on Comp­ton back-scat­ter­ing. These emerg­ing novel sources, gen­er­at­ing tun­able, mono-chro­mat­ic, bright pho­ton beams in the range of 5-20 MeV for nu­cle­ar physics as well as nu­cle­ar en­gi­neer­ing, rely on both, high qual­i­ty elec­tron beams and J-class high rep­e­ti­tion-rate syn­chro­nized laser sys­tems in order to achieve the max­i­mum spec­tral den­si­ty of the gam­ma-ray beam (# pho­tons/sec/eV). The best op­tion among the con­ven­tion­al­ly used RF linac-bands (S, C, X) and pos­si­ble hy­brid schemes will be an­a­lyzed and dis­cussed, fo­cus­ing the study in terms of best per­for­mances for the gam­ma-ray source, its re­li­a­bil­i­ty and com­pact­ness. We show that the best pos­si­ble can­di­dates for a Gam­ma-ray driv­er are quite sim­i­lar to those of FEL Linacs.  
 
THPS101 Present and Perspectives of the Sparc THz Source 3669
 
  • E. Chiadroni, M. Bellaveglia, M. Boscolo, M. Castellano, G. Di Pirro, M. Ferrario, G. Gatti, E. Pace, C. Vaccarezza
    INFN/LNF, Frascati (Roma), Italy
  • P. Calvani, S. Lupi, A. Nucara
    Università di Roma I La Sapienza, Roma, Italy
  • L. Catani, B. Marchetti
    INFN-Roma II, Roma, Italy
  • A. Cianchi
    Università di Roma II Tor Vergata, Roma, Italy
  • O. Limaj
    University of Rome La Sapienza, Rome, Italy
  • A. Mostacci, L. Palumbo
    Rome University La Sapienza, Roma, Italy
  • C. Ronsivalle
    ENEA C.R. Frascati, Frascati (Roma), Italy
  
  The de­vel­op­ment of ra­di­a­tion sources in the THz spec­tral re­gion has be­come more and more in­ter­est­ing be­cause of the pe­cu­liar char­ac­ter­is­tics of this ra­di­a­tion: it is non ion­iz­ing, it pen­e­trates di­electrics, it is high­ly ab­sorbed by polar liq­uids, high­ly re­flect­ed by met­als and re­veals spe­cif­ic "fin­ger­print" ab­sorp­tion spec­tra aris­ing from fun­da­men­tals phys­i­cal pro­cess­es. The THz source at SPARC is an ac­cel­er­a­tor based source for re­search in­ves­ti­ga­tions (e.g. ma­te­ri­al sci­ence, bi­ol­o­gy fields). Its mea­sured peak power is of the order of 108 W, very com­pet­i­tive with re­spect to other pre­sent sources. The pre­sent sta­tus of the source is pre­sent­ed and fu­ture per­spec­tives are pre­sent­ed.