• M. Ferrario, D. Alesini, F. A. Anelli, M. Bellaveglia, M. Boscolo, L. Cacciotti, M. Castellano, E. Chiadroni, L. Cultrera, G. Di Pirro, L. Ficcadenti, D. Filippetto, S. Fioravanti, A. Gallo, G. Gatti, A. Mostacci, E. Pace, R.S. Sorchetti, C. Vaccarezza
  INFN/LNF, Frascati (Roma)
• A. Bacci, V. Petrillo, A.R. Rossi, L. Serafini
  Istituto Nazionale di Fisica Nucleare, Milano
• A. Cianchi, B. Marchetti
  INFN-Roma II, Roma
• L. Giannessi, A. Petralia, C. Ronsivalle
  ENEA C.R. Frascati, Frascati (Roma)
• O. Limaj
  University of Rome La Sapienza, Rome
• M. Moreno, M. Serluca
  INFN-Roma, Roma
• J.B. Rosenzweig
  UCLA, Los Angeles, California
• H. Tomizawa
  JASRI/SPring-8, Hyogo-ken
• C. Vicario
  PSI, Villigen

The pri­ma­ry goal of the SPARC pro­ject is the com­mis­sion­ing of the SASE FEL op­er­at­ing at 500 nm driv­en by a 150-200 MeV high bright­ness pho­toin­jec­tor. Ad­di­tion­al ex­per­i­ments are fore­seen also in the HHG Seed­ed con­fig­u­ra­tion at 266, 160 and 114 nm. A sec­ond beam line host­ing a THz source has been re­cent­ly com­mis­sioned. The re­cent suc­cess­ful op­er­a­tion of the SPARC in­jec­tor in the Ve­loc­i­ty Bunch­ing (VB) mode has opened new per­spec­tives to con­duct ad­vanced beam dy­nam­ics ex­per­i­ments with ul­tra-short elec­tron puls­es able to ex­tend the THz spec­trum and to drive the FEL in the SASE Sin­gle Spike mode. More­over a new tech­nique called Laser Comb, able to gen­er­ate a train of short puls­es with high rep­e­ti­tion rate, as the one re­quired to drive co­her­ent plas­ma wake field ex­ci­ta­tion, has been test­ed in the VB con­fig­u­ra­tion. The en­er­gy/den­si­ty mod­u­la­tion pro­duced by an in­frared laser pulse in­ter­act­ing with the elec­tron beam near the cath­ode has been also in­ves­ti­gat­ed. In this paper we re­port the ex­per­i­men­tal re­sults ob­tained so far and the com­par­i­son with sim­u­la­tions.

• P. Antici, A. Mostacci
  INFN/LNF, Frascati (Roma)
• C. Benedetti
  Bologna University, Bologna
• M. Migliorati, L. Palumbo
  Rome University La Sapienza, Roma

Elec­tron beams pro­duced by laser-plas­ma in­ter­ac­tion are at­tract­ing the in­ter­est of the con­ven­tion­al ac­cel­er­a­tor com­mu­ni­ty. In par­tic­u­lar Laser-ac­cel­er­at­ed elec­trons are par­tic­u­lar­ly in­ter­est­ing as source, con­sid­er­ing their high ini­tial en­er­gy and their strong beam cur­rent. More­over, the ad­van­tages of using laser-plas­ma elec­tron beam can be ex­pressed in terms of size and cost of the glob­al ac­cel­er­at­ing in­fras­truc­ture. How­ev­er, im­prove­ments are still nec­es­sary since, cur­rent­ly, the many laser-ac­cel­er­at­ed beams are char­ac­ter­ized by a large en­er­gy spread and a high beam di­ver­gence that de­grades quick­ly the elec­tron beam prop­er­ties and makes those sources not suit­able as a re­place­ment of con­ven­tion­al ac­cel­er­a­tors. In this paper, we re­port on the progress of the study re­lat­ed to cap­ture, shape and trans­port of laser gen­er­at­ed elec­trons by means of track­ing codes. Our study has fo­cused on laser-gen­er­at­ed elec­trons ob­tained nowa­days by con­ven­tion­al multi hun­dred TW laser sys­tems and on nu­mer­i­cal pre­dic­tions. We an­a­lyze dif­fer­ent lat­tice struc­tures, work­ing on the op­ti­miza­tion of the cap­ture and trans­port of laser-ac­cel­er­at­ed elec­trons. Re­sults and open prob­lems are shown and dis­cussed.

• D. Filippetto, M. Bellaveglia, E. Chiadroni, A. Gallo, B. Marchetti
  INFN/LNF, Frascati (Roma)
• A. Cianchi
  INFN-Roma II, Roma
• A. Mostacci
  Rome University La Sapienza, Roma
• C. Ronsivalle
  ENEA C.R. Frascati, Frascati (Roma)

Ul­tra-short elec­tron bunch pro­duc­tion is at­trac­tive for a large num­ber of ap­pli­ca­tions rang­ing from short wave­length free elec­tron lasers (FEL), THz ra­di­a­tion pro­duc­tion, lin­ear col­lid­ers and plas­ma wake field ac­cel­er­a­tors. SPARC is a test fa­cil­i­ty able to ac­cel­er­ate high bright­ness beam from RF guns up to 150 MeV al­low­ing a wide range of beam physics ex­per­i­ments. Those ex­per­i­ments re­quire de­tailed beam mea­sure­ments and care­ful data anal­y­sis. In this paper we dis­cuss the tech­niques cur­rent­ly used in our ma­chine; by com­bin­ing quadrupoles, RF de­flec­tor, spec­trom­e­ter dipole and re­li­able data anal­y­sis codes, we man­age to char­ac­ter­ize the 6D phase space and the beam slice prop­er­ties. We focus on the on­go­ing stud­ies on the emit­tance com­pen­sa­tion in the ve­loc­i­ty bunch­ing regime.

• E. Chiadroni, F. A. Anelli, M. Bellaveglia, M. Boscolo, M. Castellano, L. Cultrera, G. Di Pirro, M. Ferrario, L. Ficcadenti, D. Filippetto, S. Fioravanti, G. Gatti, E. Pace, R.S. Sorchetti, C. Vaccarezza
  INFN/LNF, Frascati (Roma)
• A. Bacci, A.R. Rossi
  Istituto Nazionale di Fisica Nucleare, Milano
• P. Calvani, S. Lupi, D. Nicoletti
  Università di Roma I La Sapienza, Roma
• L. Catani, B. Marchetti
  INFN-Roma II, Roma
• A. Cianchi
  Università di Roma II Tor Vergata, Roma
• O. Limaj
  University of Rome La Sapienza, Rome
• A. Mostacci
  Rome University La Sapienza, Roma
• C. Ronsivalle
  ENEA C.R. Frascati, Frascati (Roma)

The re­gion of the spec­trum from 0.3 to 5 THz is of great in­ter­est for sev­er­al ex­per­i­ments in dif­fer­ent areas of re­search. A THz ra­di­a­tion source can be pro­duced at SPARC as co­her­ent tran­si­tion ra­di­a­tion emit­ted by ei­ther a com­pressed or lon­gi­tu­di­nal­ly mod­u­lat­ed beam in­ter­cept­ing a metal foil placed at 45° with re­spect to the beam prop­a­ga­tion. Re­sults on the char­ac­ter­i­za­tion of the THz source at SPARC are de­scribed in the paper.

Slides

• R. Boni, D. Alesini, M. Bellaveglia, G. Di Pirro, M. Ferrario, L. Ficcadenti, A. Gallo, F. Marcellini, E. Pace, B. Spataro, C. Vaccarezza
  INFN/LNF, Frascati (Roma)
• A. Bacci
  Istituto Nazionale di Fisica Nucleare, Milano
• A. Mostacci, L. Palumbo, V. Spizzo
  Rome University La Sapienza, Roma
• C. Ronsivalle
  ENEA C.R. Frascati, Frascati (Roma)

In the frame of the SPARC-X pro­ject, the en­er­gy of the Pho­to-In­jec­tor SPARC, in op­er­a­tion at INFN-LNF, will be up­grad­ed from 180 to 250 MeV by re­plac­ing a low gra­di­ent S-band trav­el­ing wave ac­cel­er­at­ing sec­tion with two C-band units, de­signed and de­vel­oped at LNF. The new sys­tem will con­sist of a 50 MW klystron, sup­plied by a pulsed mod­u­la­tor, to feed the high gra­di­ent C-band struc­tures through a RF pulse com­pres­sor. This paper deals with the de­sign of the full sys­tem, the C-band R&D ac­tiv­i­ty and study of the re­lat­ed beam dy­nam­ics.

• A. Mostacci, M. Migliorati, L. Palumbo
  Rome University La Sapienza, Roma
• D. Alesini, P. Antici
  INFN/LNF, Frascati (Roma)
• L. Picardi, C. Ronsivalle
  ENEA C.R. Frascati, Frascati (Roma)

Pro­tons gen­er­at­ed by the ir­ra­di­a­tion of a thin metal foil by a high-in­ten­si­ty short-pulse laser have shown to poss­es in­ter­est­ing char­ac­ter­is­tics in terms of en­er­gy, emit­tance, cur­rent and pulse du­ra­tion. They might there­fore be­come in the next fu­ture a com­pet­i­tive source to con­ven­tion­al pro­ton sources. Pre­vi­ous the­o­ret­i­cal and nu­mer­i­cal stud­ies al­ready demon­strat­ed the pos­si­bil­i­ty of an ef­fi­cient cou­pling be­tween laser-plas­ma ac­cel­er­a­tion of pro­tons with tra­di­tion­al RF based beam-line ac­cel­er­a­tor tech­niques. This hy­brid pro­ton ac­cel­er­a­tor would there­fore ben­e­fit from the good prop­er­ties of the laser-based source and from the flex­i­bil­i­ty and know-how of beam han­dling as given from RF based ac­cel­er­a­tor struc­ture. The pro­ton beam pa­ram­e­ters of the source have been ob­tained from pub­lished laser in­ter­ac­tion ex­per­i­men­tal re­sults and are given as input to the nu­mer­i­cal study by con­ven­tion­al ac­cel­er­a­tor de­sign tools. In this paper we dis­cuss re­cent re­sults in the op­ti­miza­tion and de­sign of the such hy­brid schemes in the con­text of pro­ton ac­cel­er­a­tors for med­i­cal treat­ments.

• S. Gerstl, T. Baumbach, S. Casalbuoni, A.W. Grau, M. Hagelstein, D. Saez de Jauregui
  Karlsruhe Institute of Technology (KIT), Karlsruhe
• V. Baglin
  CERN, Geneva
• C. Boffo, G. Sikler
  BNG, Würzburg
• T.W. Bradshaw
  STFC/RAL, Chilton, Didcot, Oxon
• R. Cimino, M. Commisso, B. Spataro
  INFN/LNF, Frascati (Roma)
• J.A. Clarke, D.J. Scott
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• M.P. Cox, J.C. Schouten
  Diamond, Oxfordshire
• R.M. Jones, I.R.R. Shinton
  UMAN, Manchester
• A. Mostacci
  Rome University La Sapienza, Roma
• E.J. Wallén
  MAX-lab, Lund
• R. Weigel
  Max-Planck Institute for Metal Research, Stuttgart

One of the still open is­sues for the de­vel­op­ment of su­per­con­duct­ing in­ser­tion de­vices is the un­der­stand­ing of the beam heat load. With the aim of mea­sur­ing the beam heat load to a cold bore and the hope to gain a deep­er un­der­stand­ing in the beam heat load mech­a­nisms, a cold vac­u­um cham­ber for di­ag­nos­tics is under con­struc­tion. The fol­low­ing di­ag­nos­tics will be im­ple­ment­ed: i) re­tard­ing field an­a­lyz­ers to mea­sure the elec­tron flux, ii) tem­per­a­ture sen­sors to mea­sure the total heat load, iii) pres­sure gauges, iv) and mass spec­trom­e­ters to mea­sure the gas con­tent. The inner vac­u­um cham­ber will be re­mov­able in order to test dif­fer­ent ge­ome­tries and ma­te­ri­als. This will allow the in­stal­la­tion of the cryo­stat in dif­fer­ent syn­chrotron light sources. COLD­DI­AG will be built to fit in a short straight sec­tion at ANKA. A first in­stal­la­tion at the syn­chrotron light source DI­A­MOND is under dis­cus­sion. Here we de­scribe the tech­ni­cal de­sign re­port of this de­vice and the planned mea­sure­ments with beam.