ENEA C.R. Frascati, Frascati (Roma)
INFN/LNF, Frascati (Roma)
Rome University La Sapienza, Roma
LBNL, Berkeley, California
The SPARX X-FEL accelerator will be the first FEL facility to operate with a hybrid (RF plus magnetic chicane) compression scheme. Numerical studies of propagation of beam density modulations stemming from photogun laser, through the photoinjector operating under velocity bunching conditions have been carried out. A semi-analytical model for the linear gain in a RF compressor is also being developed and some preliminary results are presented.
INFN/LNF, Frascati (Roma)
ENEA C.R. Frascati, Frascati (Roma)
Rome University La Sapienza, Roma
LBNL, Berkeley, California
The modeling of the microbunching instability has been carried out for the SPARX FEL accelerator, two configurations have been considered and compared: hybrid compression scheme (velocity bunching plus magnetic compressor) and purely magnetic. The effectiveness of a laser heather in reducing this instability drawbacks on the electron beam quality has also been exploited. Analytical predictions and start to end simulation results are reported in this paper.
Universita' degli Studi di Milano, Milano
Istituto Nazionale di Fisica Nucleare, Milano
INFN/LNF, Frascati (Roma)
ENEA C.R. Frascati, Frascati (Roma)
INFN-Roma, Roma
In this paper a possible experiment with the existing SPARC photoinjector is described to generate sub-picosecond high brightness electron bunches able to produce single spike radiation pulses at 500 nm with the SPARC self-amplified spontaneous emission free-electron laser (SASE-FEL). The main purpose of the experiment will be the production of short electron bunches as long as few SASE cooperation lengths, the determination of the shape of the radiation pulse and the validation of the single spike scaling law, in order to foresee operation at shorter wavelength in the future operation with SPARX. We present in this paper start to end simulations regarding the beam production and FEL performance, and discuss the layout of the machine. The experience, gained from this experiment, will help in the configuration of the VUV and X-ray FEL SPARX to obtain FEL pulses below 10 fs.
INFN/LNF, Frascati (Roma)
UCLA, Los Angeles, California
Istituto Nazionale di Fisica Nucleare, Milano
INFN-Roma II, Roma
ENEA C.R. Frascati, Frascati (Roma)
University of Tehran, Tehran
INFN-Roma, Roma
One of the main goals of the SPARC high brightness photoinjector is the experimental demonstration of the emittance compensation process while compressing the beam with the velocity bunching technique, also named RF compressor. For this reason, the first two S-band travelling wave accelerating structures downstream of the RF gun are embedded in a long solenoid, in order to control the space charge induced emittace oscillations during the compression process. An RF deflecting cavity placed at the exit of the third accelerating structure allows bunch length measurements with a resolution of 50 μm. During the current SPARC run a parametric experimental study of the velocity bunching technique has been performed. The beam bunch length and projected emittance have been measured at 120 MeV as a function of the injection phase in the first linac, and for different solenoid field values. In this paper we describe the experimental layout and the results obtained thus far. Comparisons with simulations are also reported.
Università di Roma II Tor Vergata, Roma
INFN/LNF, Frascati (Roma)
Rome University La Sapienza, Roma
INFN-Roma II, Roma
ENEA C.R. Frascati, Frascati (Roma)
The SPARC photoinjector drives a SASE FEL to perform several experiments both for the production of high brightness electron beam and for testing new scheme of SASE radiation generation. The control of the beam properties, in particular at the level of the slice dimension, is crucial in order to optimize the FEL process. We report the different measurements performed in order to characterize the slice properties of the electron beam.
ENEA C.R. Frascati, Frascati (Roma)
SPARKLE S.r.l., Casarano (Lecce)
SPARKLE company is setting up in the south of Italy (Casarano) a new cyclotron facility based on a 18 MeV, 150 uA IBA Cyclone 18/9. The aim is to create a multidisciplinary research site for the medical applications of accelerators. The main activity will be the production of standard and new radionuclides, by internal targets and one external beam line. Another opposite beam line has been reserved for low current proton irradiations for radiotherapy studies, and a linac booster between 18 and 24 MeV was designed and built to this end. The beam line, which focuses and matches the beam to the linac, includes a chopping system to synchronize the beam to the pulsed linac and to collect 99% of the beam not synchronous to the linac. The linac uses a 3 GHz SCDTL structure powered by a magnetron modulator system. In the paper we report an overview of the beam line, component design, and tests.
INFN/LNF, Frascati (Roma)
Istituto Nazionale di Fisica Nucleare, Milano
CEA, Gif-sur-Yvette
INFN-Roma II, Roma
ENEA C.R. Frascati, Frascati (Roma)
SOLEIL, Gif-sur-Yvette
INFN-Roma, Roma
University of Tehran, Tehran
UCLA, Los Angeles, California
The SPARC project foresees the realization of a high brightness photo-injector to produce a 150-200 MeV electron beam to drive 500 nm FEL experiments in SASE, Seeding and Single Spike configurations. The SPARC photoinjector is also the test facility for the recently approved VUV FEL project named SPARX. The second stage of the commissioning, that is currently underway, foresees a detailed analysis of the beam matching with the linac in order to confirm the theoretically prediction of emittance compensation based on the “invariant envelope” matching , the demonstration of the “velocity bunching” technique in the linac and the characterisation of the spontaneous and stimulated radiation in the SPARC undulators. In this paper we report the experimental results obtained so far. The possible future energy upgrade of the SPARC facility to produce UV radiation and its possible applications will also be discussed.
