Towards the achievement of megatesla magnetic fields in the laboratory


Date:
December 9, 2021
Source:
Osaka University
Summary:
Researchers have conducted high-precision 3D supercomputer
simulations to reveal the 3D structure of theoretically predicted
micron-scale megatesla magnetic fields, which optimizes engineering
design of laser conditions and micron-size target structures for
future laser experiments.



FULL STORY ========================================================================== Recently, a research team at Osaka University has successfully
demonstrated the generation of megatesla (MT)-order magnetic fields via three-dimensional particle simulations on laser-matter interaction. The strength of MT magnetic fields is 1-10 billion times stronger than
geomagnetism (0.3-0.5 G), and these fields are expected to be observed
only in the close vicinity of celestial bodies such as neutron stars
or black holes. This result should facilitate an ambitious experiment
to achieve MT-order magnetic fields in the laboratory, which is now
in progress.


========================================================================== Since the 19th century, scientists have strived to achieve the highest
magnetic fields in the laboratory. To date, the highest magnetic field
observed in the laboratory is in the kilotesla (kT)-order. In 2020,
Masakatsu Murakami at Osaka University proposed a novel scheme called
microtube implosions (MTI) to generate ultrahigh magnetic fields on the MT-order. Irradiating a micron-sized hollow cylinder with ultraintense
and ultrashort laser pulses generates hot electrons with velocities
close to the speed of light. Those hot electrons launch a cylindrically symmetric implosion of the inner wall ions towards the central axis. An
applied pre-seeded magnetic field of the kilotesla-order, parallel
to the central axis, bends the trajectories of ions and electrons in
opposite directions because of the Lorentz force. Near the target axis,
those bent trajectories of ions and electrons collectively form a strong
spin current that generates MT-order magnetic fields.

In this study, one of the team members, Didar Shokov, has extensively
conducted three-dimensional simulations using the supercomputer "OCTOPUS"
at Osaka University's Cybermedia Center. As a result, a distinct scaling
law has been found relating the performance of the generation of the
magnetic fields by MTI and such external parameters as applied laser
intensity, laser energy, and target size.

"Our simulation showed that ultrahigh megatesla magnetic fields, which
were thought to be impossible to realize on earth, can be achieved using today's laser technology. The scaling law and detailed temporal behavior
of the magnetic fields in the target are expected to facilitate laboratory experiments using the Peta-watt laser system 'LFEX' at Osaka University's Institute of Laser Engineering, which are now in progress," Murakami says.

========================================================================== Story Source: Materials provided by Osaka_University. Note: Content may
be edited for style and length.


========================================================================== Journal Reference:
1. D. Shokov, M. Murakami, J.J. Honrubia. Laser scaling for
generation of
megatesla magnetic fields by microtube implosions. High Power
Laser Science and Engineering, 2021; 1 DOI: 10.1017/hpl.2021.46 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/12/211209095611.htm

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