megampere

A megampere (MA) is a unit of electric current equal to one million amperes. It is formed from the ampere with the SI prefix mega, and the symbol is MA. In practical terms, it denotes extremely large currents that exceed typical engineering practice in power systems.

Megampere-scale currents are mainly encountered in high-energy physics, pulsed-power research, and certain magnetics applications. In ordinary power transmission and distribution, currents are usually expressed in kiloamperes or amperes; megamperes require specialized equipment and design to manage heating, magnetic effects, and rapid changes in current (di/dt).

Measurement of megampere currents relies on specialized instrumentation capable of handling rapid, high-magnitude pulses. Common tools include Rogowski coils, high-current shunts, and magnetic probes, all designed to endure intense magnetic fields and short timescales while maintaining accurate readings.

One megampere equals 1,000,000 amperes and also equals 1,000 kiloamperes (1 MA = 1,000 kA = 1,000,000 A). The substantial magnetic fields and energy associated with such currents mean that devices and facilities operating at this level typically rely on complex, high-precision pulse power technologies.

Notable examples of megampere currents appear in pulsed-power facilities. The Sandia National Laboratories Z Pulsed Power Facility has delivered pulses with peak currents on the order of tens of megaamperes, historically around 20–26 MA, illustrating the scale and research context in which MA-level currents are relevant.