Scaling of betatron X-ray radiation

Rousse, A.; Phuoc, K. Ta; Shah, Rahul; Fitour, R.; Albert, F.

doi:10.1140/epjd/e2007-00249-7

Cited by 31 publications

(26 citation statements)

References 35 publications

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“…Plasma-based laser wake field accelerators (LWFAs) [1,2] have recently produced electron beams in the 0.5-1.5 gigaelectronvolt GeV energy range [3][4][5][6][7][8][9][10][11]. The introduction of shortpulse, compact petawatt (PW) laser systems [12][13][14][15][16][17] opens up possibilities beyond the GeVenergy frontier [18][19][20][21][22][23], enabling further progress towards practical high-brightness x-ray sources [24][25][26][27][28][29][30][31][32][33][34][35] and compact high-energy physics particle colliders [36,37]. Femtosecond (fs)-scale duration and multi-kiloampere current of beams of electrons trapped and accelerated by the laser wake fields [38,39] are very well suited to these applications.…”

Section: Introductionmentioning

confidence: 99%

Laser plasma acceleration with a negatively chirped pulse: all-optical control over dark current in the blowout regime

et al. 2012

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Recent experiments with 100 terawatt-class, sub-50 femtosecond laser pulses show that electrons self-injected into a laser-driven electron density bubble can be accelerated above 0.5 gigaelectronvolt energy in a sub-centimetrelength rarefied plasma. To reach this energy range, electrons must ultimately outrun the bubble and exit the accelerating phase; this, however, does not ensure high beam quality. Wake excitation increases the laser pulse bandwidth by red-shifting its head, keeping the tail unshifted. Anomalous group velocity dispersion of radiation in plasma slows down the red-shifted head, compressing the pulse into a few-cycle-long piston of relativistic intensity. Pulse transformation into a piston causes continuous expansion of the bubble, trapping copious numbers of unwanted electrons (dark current) and producing a poorly collimated, polychromatic energy tail, completely dominating the electron spectrum at the dephasing limit. The process of piston formation can be mitigated by using a broad-bandwidth (corresponding to a few-cycle transform-limited duration), negatively chirped pulse. Initial blue-shift of the pulse leading edge compensates for the nonlinear frequency red-shift and delays the piston formation, thus significantly suppressing the dark current, making 3 the electron rest mass, n 0 is the background electron density and e is the electron charge. Even with the Lorentz factor γ g approaching 100, the bubble is a 'slow' structure capable of capturing and accelerating initially quiescent electrons of the ambient plasma [22,23,[45][46][47]. Optical diagnostics directly correlate the generation of a collimated electron beam with bubble formation [48][49][50][51][52]. While other (e.g. all-optical) injection schemes are currently being explored [53][54][55][56][57], electron self-injection has its own advantages: it greatly reduces the technical complexity of the experiment, preserving flexibility in parameters and enabling a single-stage acceleration of nano-Coulomb (nC) charge [23,47].Accelerated electrons eventually outrun the slow bubble. They exit the accelerating phase within a time intervalis the bubble radius and k p = ω pe /c. In strongly rarefied plasmas, where γ g k p R b , dephasing takes many Rayleigh lengths 5 . Propagation of the pulse over this distance relies on a combination of relativistic and ponderomotive self-guiding [58][59][60]. Upon entering the plasma, the pulse, with P P cr and duration τ L < 2π/ω pe , self-focuses until full electron cavitation is achieved, and the charge-separation force balances the radial ponderomotive force; the pulse is then guided until depletion (here, P cr = 16.2γ 2 g GW is the critical power for relativistic self-focusing [61]). As this force balance is approached, the bubble size oscillates, causing electron injection during a brief time interval. A QME electron bunch thus forms early [45,62,63]. However, transient dynamics before the onset of self-guiding [23], as well as laser evolution during self-guiding [5,7,22,23,[63][64][65], may cause ...

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Section: Introductionmentioning

confidence: 99%

Laser plasma acceleration with a negatively chirped pulse: all-optical control over dark current in the blowout regime

et al. 2012

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“…This kind of sources thus needs to be monochromatized for a practical use. Although the X-ray flux integrated over the whole solid angle is some orders of magnitude smaller with respect to the Kα sources, the X-ray emission has, in this case, a much smaller divergence, which is on the order of millirads; recent simulations reported in the literature [14] show that the average brightness of such a source can be expected, with 100-TW laser pulses, to be three orders of magnitude higher than in the case of the Kα sources, with typical durations that are, in this case, of a few tens of femtoseconds.…”

Section: Discussionmentioning

confidence: 79%

Linear and Nonlinear Thomson Scattering for Advanced X-ray Sources in PLASMONX

Tomassini

Bacci

Cary

et al. 2008

IEEE Trans. Plasma Sci.

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Thomson scattering of laser pulses onto ultrarelativistic e-bunches is becoming an advanced source of tunable, quasimonochromatic, and ultrashort X/gamma radiation. Sources aimed at reaching a high flux of scattered photons need to be driven by high-brightness e-beams, whereas extremely short (femtosecond scale or less) sources need to make femtosecond-long e-beams that collide with the laser pulses. In this paper, we explore the performance of the PLASMONX TS source in several operating regimes, including preliminary results on a source based on e-bunches produced by laser wakefield acceleration and controlled injection via density downramp.Index Terms-Compton scattering, Thomson scattering (TS), X-ray sources.

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“…Similarly, target and electron beam diagnostics of the wakefield hutch can draw heavily from recent progress in laser wakefield acceleration [62]. Requirements of the wakefield and optics hutch for a 10 PW beamline are to large extent beyond Table 1 Predicted radiation characteristics from the scalings for various laser parameters The current 4th generation light sources, the x-ray FEL FLASH and the x-ray LCLS, as well as upcoming XFEL; For comparison, peak brightness obtained from a laser solid target K a [60] source and a laser solid target high-harmonic source [14]; All other curves taken from [61]. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)…”

Section: Schematic Of a Potential Plasma Wiggler Beamlinementioning

confidence: 99%