Ultrahigh brightness electron beams by plasma based injectors for driving all optical free electron lasers
Articolo
Data di Pubblicazione:
2008
Citazione:
Ultrahigh brightness electron beams by plasma based injectors for driving all optical free electron lasers / V. Petrillo, L. Serafini, P. Tomassini. - In: PHYSICAL REVIEW SPECIAL TOPICS. ACCELERATORS AND BEAMS. - ISSN 1098-4402. - 11:7(2008), pp. 070703.070703.1-070703.070703.7.
Abstract:
We studied the generation of low emittance high current monoenergetic beams from plasma waves
driven by ultrashort laser pulses, in view of achieving beam brightness of interest for free-electron laser
(FEL) applications. The aim is to show the feasibility of generating nC charged beams carrying peak
currents much higher than those attainable with photoinjectors, together with comparable emittances and
energy spread, compatibly with typical FEL requirements. We identified two regimes: the first is based on
a laser wakefield acceleration plasma driving scheme on a gas jet modulated in areas of different densities
with sharp density gradients. The second regime is the so-called bubble regime, leaving a full electron-free
zone behind the driving laser pulse: with this technique peak currents in excess of 100 kA are achievable.
We have focused on the first regime, because it seems more promising in terms of beam emittance.
Simulations carried out using VORPAL show, in fact, that in the first regime, using a properly density
modulated gas jet, it is possible to generate beams at energies of about 30 MeV with peak currents of
20 kA, slice transverse emittances as low as 0.3 mm mrad, and energy spread around 0.4%. These beams
break the barrier of 1018 A= mmmrad 2 in brightness, a value definitely above the ultimate performances
of photoinjectors, therefore opening a new range of opportunities for FEL applications. A few examples of
FELs driven by such kind of beams injected into laser undulators are finally shown. The system
constituted by the electron beam under the effect of the electromagnetic undulator has been named
AOFEL (for all optical free-electron laser)
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
V. Petrillo, L. Serafini, P. Tomassini
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