Generation of collimated electron jets from plasma under applied electromagnetostatic field

AbstractThe collimated electron jets ejected from cylindrical plasma are produced in particle-in-cell simulation under the applied longitudinal magnetostatic field and radial electrostatic field, which is a process that can be conveniently performed in a laboratory. We find that the applied magnetostatic field contributes significantly to the jet collimation, whereas the applied electrostatic field plays a vital role in the jet formation. The generation mechanism of collimated jets can be well understood through energy gain of the tagged electrons, and we conclude that the longitudinal momentum of the electrons is converted from the transverse momentum via the transverse-induced magnetic field. It has been found that the ejecting velocity of the jets is close to the speed of light when the applied electrostatic field reaches 3 × 1010 V/m. The present scheme may also give us an insight into the formation of astrophysical jets in celestial bodies.

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Laboratory disruption of scaled astrophysical outflows by a misaligned magnetic field

Nature Communications ◽

10.1038/s41467-021-20917-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

G. Revet ◽

B. Khiar ◽

E. Filippov ◽

C. Argiroffi ◽

J. Béard ◽

...

Keyword(s):

Magnetic Field ◽

Laboratory Experiments ◽

Magnetic Pressure ◽

Astrophysical Jets ◽

Jet Formation ◽

Magnetic Nozzle ◽

Jet Collimation ◽

Changes Over Time ◽

The Impact ◽

The Magnetic Field

AbstractThe shaping of astrophysical outflows into bright, dense, and collimated jets due to magnetic pressure is here investigated using laboratory experiments. Here we look at the impact on jet collimation of a misalignment between the outflow, as it stems from the source, and the magnetic field. For small misalignments, a magnetic nozzle forms and redirects the outflow in a collimated jet. For growing misalignments, this nozzle becomes increasingly asymmetric, disrupting jet formation. Our results thus suggest outflow/magnetic field misalignment to be a plausible key process regulating jet collimation in a variety of objects from our Sun’s outflows to extragalatic jets. Furthermore, they provide a possible interpretation for the observed structuring of astrophysical jets. Jet modulation could be interpreted as the signature of changes over time in the outflow/ambient field angle, and the change in the direction of the jet could be the signature of changes in the direction of the ambient field.

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Enhanced laser ion acceleration with a multi-layer foam target assembly

Laser and Particle Beams ◽

10.1017/s0263034614000342 ◽

2014 ◽

Vol 32 (4) ◽

pp. 509-515 ◽

Cited By ~ 10

Author(s):

E. Yazdani ◽

R. Sadighi-Bonabi ◽

H. Afarideh ◽

J. Yazdanpanah ◽

H. Hora

Keyword(s):

Proton Energy ◽

Critical Density ◽

Maximum Energy ◽

Longitudinal Momentum ◽

Free Electrons ◽

Particle In Cell ◽

Direct Laser ◽

Linearly Polarized ◽

Cell Simulation ◽

Laser Acceleration

AbstractInteraction of a linearly polarized Gaussian laser pulse (at relativistic intensity of 2.0 × 1020 Wcm−2) with a multi-layer foam (as a near critical density target) attached to a solid layer is investigated by using two-dimensional particle-in-cell simulation. It is found that electrons with longitudinal momentum exceeding the free electrons limit of meca02/2 so-called super-hot electrons can be produced when the direct laser acceleration regime is fulfilled and benefited from self-focusing inside of the subcritical plasma. These electrons penetrate easily through the target and can enhance greatly the sheath field at the rear, resulting in a significant increase in the maximum energy of protons in target normal sheath acceleration regime. The results indicate that the maximum proton energy is enhanced by 2.7 times via using an assembled target arrangement compared to a bare solid target. Furthermore, by demonstration of this assembly, the maximum proton energy is improved beyond the optimum amount achieved by a two-layer target proposed by Sgattoni et al. (2012).

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