High energy electrons from interaction with a 10 mm gas-jet at FLAME

Year: 2013

Authors: Grittani GM., Anania MP., Gatti G., Giulietti D., Kando M., Krus M., Labate L., Levato T., Oishi Y., Rossi F., Gizzi LA.

Autors Affiliation: ILIL, INO-CNR, Via Moruzzi, 1, 56124 Pisa, Italy; INFN, Sez. Pisa, Largo B. Pontecorvo, 3, 56127 Pisa, Italy; Dipartimento di Fisica E. Fermi, Università di Pisa, Italy; Laboratori Nazionali di Frascati, INFN, Via E. Fermi, Frascati, Italy; Japan Atomic Energy Agency (JAEA), Kyoto, Japan; Fyzikàlnì ùstav AV CR v.v.i., Praha, Czech Republic; U. Tor Vergata, Roma, Italy; CRIEPI, Kanagawa, Japan; Università di Bologna e Sez. INFN, Bologna, Italy

Abstract: In this paper we discuss the spectra of the electrons produced in the laser-plasma acceleration experiment at FLAME. Here a <30 fs laser pulse is focused via an f/10 parabola in a focal spot of 10 mu m diameter into a 1.2 mm by 10 mm rectangular Helium gas-jets at a backing pressure ranging from 5 to 15 bar. The intensity achieved exceeds 10(19) Wcm(-2). In our experiment the laser is set to propagate in the gas-jet along the longitudinal axis to use the 10 mm gas-jet length and to evaluate the role of density gradients. The propagation of the laser pulse in the gas is monitored by means of a Thomson scattering optical imaging. Accelerated electrons are set to propagate for 47,5 cm before being detected by a scintillating screen to evaluate bunch divergence and pointing. Alternatively, electrons are set to propagate in the field of a magnetic dipole before reaching the scintillating screen in order to evaluate their energy spectrum. Our experimental data show highly collimated bunches (<1 mrad) with a relatively stable pointing direction (<10 mrad). Typical bunch electron energy ranges between 50 and 200 MeV with occasional exceptional events of higher energy up to 1GeV. Journal/Review: PROCEEDINGS OF SPIE

Volume: 8779      Pages from: 87791B  to: 87791

More Information: We thank the staff of the LNF Accelerator and Technical Divisions for the support during the the SITE operations at LNF. \”SITE\” and \”-RESIST\” are funded by INFN through the CN5. The work was carried out in collaboration with the High Field Photonics Unit at INO-CNR (MD.P03.034) and was partially funded by CNR through the ELI-Italy project.
KeyWords: Electrons; Lasers; Magnetism; Optical;
DOI: 10.1117/12.2027030