The SPARX (Sorgente Pulsata Autoamplificata di Radiazione X) FEL project is aiming at the realization of a coherent light source of X-rays covering the range of wavelengths (λ) ranging from 0.6 to 40 nm at fundamental harmonic, and will be able to reach the Ångstrom-region using the third and fifth harmonics where high power is still produced.

SPARX covers a radiation region complementary to those of other existing or in construction facilities, such as FLASH (λ>6 nm), FERMI (10<λ<100 nm), X-FEL (0.1<λ<1.6 nm), LCLS (0.15<λ<1.5 nm), SCSS (λ>0.1 nm), and will produce, with special magnets, radiation up to the THz region.

These ranges of wavelengths, showing some convenient overlap, have the advantage of providing sufficient access to users, expected to be proposing experiments in many fields of disciplines, and ensuring at the same time a beneficial level of competitiveness. 

Furthermore, the available site for the construction of SPARX does not limit the expansibility of the facility for future upgrades up to the Ångstrom-region in the first harmonic. 

It is worth reminding that the SPARX initiative follows the path of a long tradition in the development of Synchrotron Light sources and FELs concentrated in the Frascati area since the late ‘50s.

Here, pioneer researchers constructed the first Italian synchrotron, and the first-in-the-world colliding electron-positron storage ring “ADA”, where radiation-beam phenomena, up to then unknown, were discovered and interpreted by Bruno Touschek and his team.

Eventually, dedicated Synchrotron radiation beam-lines were built, in collaboration with CNR, on the storage ring ADONE where two generations of Italian synchrotron radiation scientists were trained and developed world wide recognized cutting-edge experiments.

More recently, a high level of expertise has been reached by ENEA and INFN on FEL’s physics and technology.