Tesla (unit) Los Alamos National Laboratory campus of the National High Magnetic Field Laboratory, the world's first 100-tesla non-destructive magnetic field. In September 2018 researchers at the University of Tokyo generated a field of 1200 T which lasted in the order of 100 microseconds using the electromagnetic flux-compression technique. A particle, carrying a charge of one coulomb, and moving perpendicularly through a magnetic field of one tesla, at a speed of one metre per second, experiences a force with magnitude one newton, according to the Lorentz force law. As an SI derived unit, the tesla can also be expressed as (The last
Current density is the charge density (SI unit: coulombs per cubic metre), in which "n"(r, "t") is the number of particles per unit volume ("number density") (SI unit: m), "q" is the charge of the individual particles with density "n" (SI unit: coulombs). A common approximation to the current density assumes the current simply is proportional to the electric field, as expressed by: where E is the electric field and "σ" is the electrical conductivity. Conductivity "σ" is the reciprocal (inverse) of electrical resistivity and has the SI units of siemens per metre (S⋅m), and E has the SI units of newtons