Sign reversal in magnetic field amplification by relativistic laser-driven microtube implosions
[1];
[2];
[3];
[4]
- University of California at San Diego, La Jolla, CA (United States). Department of Mechanical and Aerospace Engineering
- Osaka University, Suita, Osaka (Japan). Institute of Laser Engineering
- Science and Technology Facilities Council (STFC), Rutherford-Appleton Laboratory, Didcot (United Kingdom). Central Laser Facility
- University of California at San Diego, La Jolla, CA (United States). Department of Mechanical and Aerospace Engineering; University of California San Diego, La Jolla, CA (United States). Center for Energy Research
In this work, we demonstrate and explain the surprising phenomenon of sign reversal in magnetic field amplification by the laser-driven implosion of a structured target. Relativistically intense laser pulses incident on the outer surface of a microtube target consisting of a thin opaque shell surrounding a μm-scale cylindrical void drive an initial ion implosion and later explosion capable of generating and subsequently amplifying strong magnetic fields. While the magnetic field generation is enhanced and spatially smoothed by the application of a kilotesla-level seed field, the sign of the generated field does not always follow the sign of the seed field. One unexpected consequence of the amplification process is a reversal in the sign of the amplified magnetic field when, for example, the target outer cross section is changed from square to circular. Using 2D particle-in-cell simulations, we demonstrate that sign reversal is linked to the stability of the surface magnetic field of opposite sign from the seed, which arises at the target inner surface during laser irradiation. The stability of the surface magnetic field and, consequently, the sign of the final amplified field depend sensitively on the target, laser, and seed magnetic field conditions, which could be leveraged to make laser-driven microtube implosions an attractive platform for the study of magnetic fields in high energy density plasma in regimes where sign reversal either is or is not desired.
- Research Organization:
- Univ. of California, San Diego, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); Engineering and Physical Sciences Research Council (EPSRC); National Science Foundation (NSF)
- Grant/Contract Number:
- SC0018312; EP/G054940; EP/G055165; EP/G056803; ACI-1548562
- OSTI ID:
- 1852590
- Alternate ID(s):
- OSTI ID: 1735783
- Journal Information:
- Applied Physics Letters, Vol. 117, Issue 24; ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Laser reflection as a catalyst for direct laser acceleration in multipicosecond laser-plasma interaction
Emission of electromagnetic waves as a stopping mechanism for nonlinear collisionless ionization waves in a high-β regime