Title: Field reconstruction from proton radiography of intense laser driven magnetic reconnection

Abstract

Magnetic reconnection is a process that contributes significantly to plasma dynamics and energy transfer in a wide range of plasma and magnetic field regimes, including inertial confinement fusion experiments, stellar coronae and compact, highly magnetized objects like neutron stars. Laboratory experiments in different regimes can help refine, expand and test the applicability of theoretical models to describe reconnection. Laser-plasma experiments exploring magnetic reconnection at moderate intensities (I_L ~ 10¹⁴ Wcm^-2) have been performed previously, where the Biermann battery effect self-generates magnetic fields and the field dynamics studied using proton radiog- raphy. At high laser intensities (I_Lλ$$2\atop{L}$$ > 10¹⁸ Wcm^-2 μm² ), relativistic surface currents and the time-varying electric sheath fields generate the azimuthal magnetic fields. Numerical modeling of these intensities has shown the conditions within the magnetic field region can reach the threshold where the magnetic energy can exceed the rest mass energy such that σ_cold = B²/(μ₀n_em_ec²) > 1 [A. E. Raymond, et al., Phys. Rev. E, 98, 043207 (2018)]. Presented here is the analysis of the proton radiography of a high-intensity (~ 10¹⁸ Wcm^-2) laser driven magnetic reconnection geometry. Lastly, the path integrated magnetic fields are recovered using a “field-reconstruction algorithm” to quantify the field strengths, geometry and evolution.

Authors:

Palmer, Charlotte ^[1]; Campbell, Paul ^[2]; Ma, Yong ^[2]; Antonelli, Luca ^[3]; Bott, Archie ^[1]; Gregori, Gianluca ^[1]; Halliday, James ^[4]; Katzir, Yiftak ^[5]; Kordell, Peter ^[2]; Krushelnick, Karl ^[2]; Lebedev, Sergei ^[4]; Montgomery, Emer ^[5]; Notley, Margaret ^[5]; Carroll, David ^[5]; Ridgers, Christopher ^[3]; Schekochihin, Alex ^[1]; Streeter, Matthew ^[4]; Thomas, Alexander ^[2]; Tubman, Eleanor ^[4]; Woolsey, Nigel ^[3] more »; Willingale, Louise ^[2] « less

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+ Show Author Affiliations

1. Univ. of Oxford (United Kingdom)
2. Univ. of Michigan, Ann Arbor, MI (United States)
3. Univ. of York (United Kingdom)
4. Imperial College, London (United Kingdom)
5. Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab.

Publication Date:

2019-07-26

Research Org.:

Univ. of Michigan, Ann Arbor, MI (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1545010

Alternate Identifier(s):

OSTI ID: 1557377

Grant/Contract Number:  

NA0002727

Resource Type:

Accepted Manuscript

Journal Name:

Physics of Plasmas

Additional Journal Information:

Journal Volume: 26; Journal Issue: 8; Journal ID: ISSN 1070-664X

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

70 PLASMA PHYSICS AND FUSION TECHNOLOGY