• 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.

• 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.

• 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.

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