Ultra-bright γ-ray emission by using PW laser irradiating solid target obliquely

Abstract

By using intense laser irradiating a micro plane target obliquely, an enhanced γ-ray source is generated. Due to the superposition of the incident and the reflected laser pulses, electron bunches with density of ∼ 300n c are extracted and accelerated. When these electron bunches separate from the edge of the target that the laser is leaving, they co-propagate with the laser field and emit dense γ-rays simultaneously. Simulation results show that the emitted γ photons are 253n c dense with an averaged energy of ∼ 12 MeV. The yield of γ photons is ∼ 7 × 10 12 , achieving a high brightness of ∼ 4 × 10 23 photons/s/mm 2 /mrad 2 /0.1%BW. Influences of the laser intensity and the incident angle on the γ-rays emission are discussed. The γ-ray yield, the conversion efficiency from the laser to the γ-rays and the averaged γ-ray energy are increasing when irradiating a higher intensity laser. With the increasing of the incident angle, the peak photon density increases when the angle is smaller than 20 • and then drops to a stable value, while the divergence decreases when the incident angle is smaller than ∼ 16 • and then increases.

Optimization and control of synchrotron emission in ultraintense laser–solid interactions using machine learning

“…The only sizeable difference in the parameters here, besides the small increase in τ L , is the change from θ i = 41.1 • to θ i ≈ 25 • . The production of more directional synchrotron emission with changes to the angle-of-incidence has been reported in references [31,46,88] , in which a single lobe structure is also reported.…”

“…The production of more directional synchrotron emission with changes to the angle-of-incidence has been reported in Refs. [31,46,88], in which a single lobe structure is also reported.…”

“…The production of more directional synchrotron emission with changes to the angle-of-incidence has been reported in Refs. [31,46,88], in which a single lobe structure is also reported.

Figure 6 Synchrotron and bremsstrahlung radiation for the objective function optima in Table 1, for which fs m W cm −2 . (a) Synchrotron photon energy spectra, (b) bremsstrahlung photon energy spectra and (c) angular profiles of total emitted synchrotron photon energy.

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Dense γ-ray emission in two consecutive pulses irradiating near critical density plasma

“…Considering the electron traverses parallel to the laser propagation direction, it is apparent that a more intense electric field favours γ-ray production. Several laser focusing techniques have been proposed to achieve higher laser intensities than those obtained in current laser facilities [31,32]. For example, micro-structurelike tubes are utilized to enhance the laser field [33] and also increase the energy deposition into the plasma [34].…”