Investigation of the effect of plasma waves excitation on target normal sheath ion acceleration using <i>fs</i> laser‐irradiating hydrogenated structures

Phys. Rev. Accel. Beams

Costa

2020

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The ions acceleration through an fs laser irradiating a reduced graphene oxide foil in a target-normalsheath-acceleration regime is investigated using a SiC detector connected in time-of-flight configuration. The experimental data indicated maximum proton energy of 1.8 MeV and a large number of carbon ions accelerated at different energies depending on their charge state. Particle-in-cell (PIC) simulations were applied to the studied target given the electron density as a function of the space and time and permitted one to evaluate the electrical field developed in the rear side of the foil driving the forward ion acceleration. The simulation indicates that the carbon ions are subjected to a lower acceleration with respect to protons, due to their slow velocity, depending on the charge-to-mass ratio. The latter does not permit carbon ions to be affected by the maximum electric field but a lower intensity due to the fast time decay of the electric field. Considering the angular emission of protons and the six carbon ions, the charge particles assume a Boltzmann energy distribution with a fixed cutoff at high energy, in agreement with the experimental measurements of ion energy.

Section: Resultssupporting

confidence: 87%

“…Recently our experiments, obtained using fs laser pulse at an intensity of about 10 18 W=cm 2 , have permitted proton acceleration to energy above 1 MeV and carbon energy up to about 6 MeV [1,2].…”

Section: Introductionmentioning

confidence: 99%

Ion acceleration by fs laser in target-normal-sheath-acceleration regime and comparison of time-of-flight spectra with particle-in-cell simulations

Phys. Rev. Accel. Beams

Costa

2020

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“…Of course, other conditions also determine the optimal ion acceleration, such as the use of p‐polarized laser light incident with an adapt angle in order to induce resonant absorption due to the generation of longitudinal plasma waves . Another interesting irradiation condition is that concerning self‐focusing and filamentation effects, resulting in the strong focalization of the laser on the over‐critical target due to the high refractive index generated by the under‐critical pre‐plasma developed in front of the target before the arrival of the main laser pulse.…”

Section: Discussionmentioning

confidence: 99%

Ion acceleration from aluminium plasma generated by a femtosecond laser in different conditions

Contributions to Plasma Physics

Rosiński

Terwińska

et al. 2020

Non-equilibrium plasma was obtained by irradiating Al foils in vacuum with a femtosecond (fs) laser at intensities of the order of 10 18 W/cm 2 . Protons and other light ions were accelerated in the forward direction by using the target-normal-sheath acceleration regime. Time-of-flight technique was employed to measure the ions' kinetic energy using SiC detectors placed at known distances and angles. The ion acceleration was monitored under different conditions of laser focal position, laser pulse energy, and laser contrast. The target was irradiated using different thicknesses and anti-reflecting graphene films. By optimizing the laser parameters, irradiation conditions, and target properties, it was possible to accelerate up to 2.3 MeV per charge state, as will be presented and discussed.

“…In all cases, protons are accelerated at energies above 700 keV, as reported in the recent literature. [31][32][33][34] The SiC and the gaf-chromic detectors, covered using 100 and 300 μm Al filter, used in the forward direction for PE, Al and Au targets, have shown a high signal using the thinner filter and very low signal using the thicker filter, as the result of the detection of X-rays and electrons in the first case and of only X-rays in the second case. The 100 and 300 μm thicker, in fact, corresponds to the electron range of electron energy of 150 and 250 keV, respectively, as calculated from NIST ESTAR Databook.…”

Section: Tnsa In Gold Targetsmentioning

confidence: 99%

Cold electrons acceleration in TNSA laser‐generated plasma using a low‐contrast fs laser

Cutroneo

Contributions to Plasma Physics

2021

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The fs laser facility in Bordeaux, delivering an intensity of 10 18 W/cm 2 at normal incidence on thin foils, has been used to induce forward electron and ion acceleration in target-normal-sheath-acceleration (TNSA) regime. Micrometric thin foils with different composition, thickness, and electron density, were prepared to promote the charge particle acceleration in the forward direction. The plasma electron and ion emission monitoring were performed on-line using SiC semiconductor detectors in time-of-flight (TOF) configuration and gaf-chromics films both covered by thin absorber filters. The experiment has permitted to accelerate electrons and protons. A special attention was placed to detect relativistic hot electrons escaping from the plasma and cold electrons returning to the target position. The electron energies of the order of 100 keV and of about 1 keV were detected as representative of hot and cold electrons, respectively. A high cold electron contribution was measured using low-contrast fs laser, while it is less evident using high-contrast fs lasers. The charge particle acceleration depends on the laser parameters, irradiation conditions, and target properties, as will be presented and discussed.