Conceptual Design of a Soft X‐ray SASE‐FEL Source

FELs based on SASE are believed to be powerful tools to explore the frontiers of basic sciences, from physics to chemistry to biology. Intense R&D programs have started in the USA and Europe in order to understand the SASE physics and to prove the feasibility of these sources. The allocation of considerable resources in the Italian National Research Plan (PNR) brought about the formation of a CNR‐ENEA‐INFN‐University of Roma "Tor Vergata" study group. A conceptual design study has been developed and possible schemes for linac sources have been investigated, bringing to the SPARX proposal. We report in this paper the results of a preliminary start to end simulation concerning one option we are considering based on an S‐band normal conducting linac with high brightness photoinjector integrated in a RF compressor

Towards a simulation-based framework for evaluating energy-efficient solutions in train operation

In this paper we propose a simulation-based framework for evaluating energyefficient solutions in train operation. The general framework is composed of an optimisation system able to generate energy-efficient station-to-station speed profiles, looped with a micro-simulation tool for simulating railway traffic conditions, in order to evaluate the impacts on railway systems (delays, conflicts) and energy savings. The optimisation system is a subroutine consisting of a Genetic Algorithm for optimal speed profile parameters optimisation, a speed profile generator, and an energy consumption model. The micro simulation tool allows the evaluation of the impact of energy efficient speed profiles on rail operation. The framework operates on a database composed of 4 subsets: timetable, rolling stock characteristics, signalling system, infrastructure features; the first subset can be considered as the result of scheduling or rescheduling procedures, while the others can be assumed to be fixed. The proposed framework has been applied on a real-scale case of an Italian suburban railway system.ISSN:1743-3509ISSN:1744-7151ISSN:1746-449

Electron linac optimization for driving bright gammaray sources based on compton back-scattering

We study the optimal lay-out and RF frequency for a room temperature GeV-class Electron Linac aimed at producing electron beams suitable for Compton backscattering based gamma-ray sources. These emerging technology of generating tunable, bright, mono-chromatic photon beams in the range 5-20 MeV for nuclear physics and nuclear engineering, relies on high quality electron beams, and J-class high rep-rate synchronized laser systems, to achieve the maximum spectral density of the gamma-ray beam (# photons/sec/eV). The best RF band among the most used in RF linacs (S, C, X) will be identified and discussed. Copyright © 2011 by IPAC'11/EPS-AG

Recent Results at the SPARC-LAB Facility

A new facility named SPARC-LAB (Sources for Plasma Accelerators and Radiation Compton with Lasers and Beams) has been recently launched at the INFN National Labs in Frascati, merging the potentialities of the old projects SPARC and PLASMONX. The SPARC project, a collaboration among INFN, ENEA and CNR, is now completed, hosting a 150 MeV high brightness electron beam injector which feeds a 12 meters long undulator. Observation of FEL radiation in the SASE, Seeded and HHG modes has been performed from 500 nm down to 40 nm wevelength. A second beam line has been also installed to drive a narrow band THz radiation source. In parallel to that, INFN decided to host a 300 TW laser that will be linked to the linac and devoted to explore laser-matter interaction, in particular with regard to laser-plasma acceleration in the self injection and external injection modes, (the PLASMONX experiments). The facility will be also used for particle driven plasma acceleration experiments (the COMB experiment). A Thomson scattering experiment coupling the electron bunch to the high-power laser to generate coherent monochromatic X-ray radiation is also in the commissioning phase

A european proposal for the compton gamma-ray source of eli-np

A European proposal is under preparation for the Compton gamma-ray Source of ELI-NP.In the Romanian pillar of ELI (the European Extreme Light Infrastructure) an advancedgamma-ray beam is foreseen, coupled to two 10 PW laser systems. The photons will begenerated by Compton back-scattering in the collision between a high quality electron beamand a high power laser. A European collaboration formed by INFN, Univ. of Roma La Sapienza,Orsay-LAL of IN2P3, Univ. de Paris Sud XI and ASTeC at Daresbury, is preparing a TDRexploring the feasibility of a machine expected to achieve the Gamma-ray beamspecifications: energy tunable between 1 and 20 MeV, narrow bandwidth (0.3%) and highspectral density, 104 photons/sec/eV. We will describe the lay-out of the 720MeV RF Linac and the collision laser with the associated optical cavity, as well as theoptimized beam dynamics to achieve maximum phase space density at the collision. Thepredicted gamma-ray spectra have been evaluated for the case at 360 MeV. Copyright ©2012 by IEEE