High Quality Content by WIKIPEDIA articles! A dense plasma focus (DPF) is a machine that produces, by electromagnetic acceleration and compression, a short-lived plasma that is so hot and dense that it can cause nuclear fusion and emit X-rays. The electromagnetic compression of the plasma is called a pinch. It was invented in the early 1960s by J.W. Mather and also independently by N.V. Filippov. The plasma focus is similar to the high-intensity plasma gun device (HIPGD) (or just plasma gun), which ejects plasma in the form of a plasmoid, without pinching it.