arXiv subjects

L. Giannessi

Publications and source records attributed to L. Giannessi.

39 records · Page 3Linked to original sources

arXiv2010

Energy Phase Correlation and Pulse Dynamics in Short Bunch High Gain FELs

We analyze the dynamics of Free Electron Laser (FEL) devices, operating with a bunched beam exhibiting a longitudinal phase space correlation. We show that the presence of an energy-position correlation term is responsible for very interesting effects like an enhancement of the peak output power, a shortening of the laser pulses and an increase of the non linearly generated harmonic intensities. We conjecture that the mechanism is due to a kind of energy tapering effect associated with the correlation. We discuss the difference of the dynamics with respect to an ordinary undulator tapering and the relative advantages.

physics.acc-ph↗

arXiv2001

Extreme Ultraviolet (EUV) Sources for Lithography based on Synchrotron Radiation

The study presented here was initiated by a discussion to investigate the possibility of using synchrotron radiation as a source for the Next Generation Lithography (NGL) based on the EUV-concept (Extreme Ultra-Violet; here 13.5 nm or 11.3 nm radiation, respectively). The requirements are: 50 W, 2% bandwidth and minimal power outside this bandwidth. Three options were investigated. The first two deal with radiation from bending magnets and undulators. The results confirm the earlier work by Oxfords Instrument and others that these light-sources lack in-band power while emitting excessive out-of-band radiation. The third approach is a FEL (Free Electron Laser) driven by a 500 MeV linear accelerator with a superconducting mini-undulator as radiation emitting device. Such a device would produce in-band EUV-power in excess of 50 W with negligible out-of-band power.

physics.acc-ph↗

arXiv2000

Measurement of the temporal response of ferroelectric cathodes

Ferroelectric ceramics are tested as photocathodes at INFN Frascati Laboratories. In order to characterize them for use in linac injectors it is important to measure the temporal shape of the emitted current. With a duration of the laser pulse of 25 ps, the required resolution is a few ps. An apparatus has been set up for the purpose, consisting of a 30 kV electron gun, a microwave deflecting cavity which translates the temporal distribution of the electron bunch into a spatial one, a fluorescent screen on which the deflected beam traces a sector of a circle and various focusing and charge measuring items. The image on the screen is detected via a CCD camera and a frame grabber. We describe the performance of the apparatus and some preliminary temporal distribution measurements.

physics.acc-ph↗