Illustration of a microtube implosion. Prior to irradiating with ultraintense laser pulses, a uniform external electromagnetic field is pre-seeded. Credit: M. Murakami
A group of scientists led by Osaka University finds “microtube implosion,” an unique system that shows the generation of megatesla-order electromagnetic fields.
Magnetic fields are utilized in numerous locations of modern-day physics and engineering, with useful applications varying from doorbells to maglev trains. Since Nikola Tesla’s discoveries in the 19th century, scientists have actually aimed to recognize strong electromagnetic fields in labs for basic research studies and varied applications, however the magnetic strength of familiar examples are reasonably weak. Geomagnetism is 0.3−0.5 gauss (G) and magnetic tomography (MRI) utilized in healthcare facilities has to do with 1 tesla (T = 104 G). By contrast, future magnetic blend and maglev trains will need electromagnetic fields on the kilotesla (kT = 107 G) order. To date, the greatest electromagnetic fields experimentally observed are on the kT order.
Recently, researchers at Osaka University found an unique system called a “microtube implosion,” and showed the generation of megatesla (MT = 1010G) order electromagnetic fields through particle simulations utilizing a supercomputer. Astonishingly, this is 3 orders of magnitude greater than what has actually ever been accomplished in a lab. Such high electromagnetic fields are anticipated just in heavenly bodies like neutron stars and great voids.
(Left) Top view of plasma characteristics in the microtube. Laser-produced hot electrons drive the growth of the inner-wall plasma into a vacuum. The microtubes are infinitesimally twisted by a pre-seeded electromagnetic field B0. (Right) An ultrahigh electromagnetic field is created at the center due to the ultrahigh spin currents jointly formed by relativistic electrons and ions. Credit: M. Murakami
Irradiating a small plastic microtube one-tenth the density of a human hair by ultraintense laser pulses produces hot electrons with temperature levels of 10s of billion of degrees. These hot electrons, together with cold ions, broaden into the microtube cavity at speeds approaching the speed of light. Pre-seeding with a kT-order electromagnetic field triggers the imploding charged particles infinitesimally twisted due to Lorenz force. Such a unique round circulation jointly produces unprecedentedly high spin currents of about 1015 ampere/cm2 on the target axis and as a result, creates ultrahigh electromagnetic fields on the MT order.
The research study carried out by Masakatsu Murakami and associates has actually verified that present laser innovation can recognize MT-order electromagnetic fields based upon the principle. The present principle for producing MT-order electromagnetic fields will cause pioneering basic research study in various locations, consisting of products science, quantum electrodynamics (QED), and astrophysics, in addition to other advanced useful applications.
Reference: “Generation of megatesla magnetic fields by intense-laser-driven microtube implosions” by M. Murakami, J. J. Honrubia, K. Weichman, A. V. Arefiev and S. V. Bulanov, 6 October 2020, Scientific Reports.
DOI: 10.1038/s41598-020-73581-4
