Tracking plasma progression in a picosecond: Physicists develop ultra-fast laser method to study high-density plasmas

In a few picoseconds (trillionths of a second), a small, thin piece of copper momentarily becomes dense plasma, specifically a state called warm dense matter, warm being a relative term—the metal is nearly 200,000 degrees Fahrenheit. With the short duration of a high-powered laser pulse, copper shifts from a solid state to a plasma state in an instant before it explodes. Understanding the progression of heat in the copper is an exciting breakthrough in physics relevant to the interior of giant planets and laser fusion fuel cores.