Observations of soft x‐ray production in the speed 2 plasma focus

A new soft x‐ray source has been developed and investigated. Argon is injected into a plasma focus through a hole in the anode. The pinch emits several Joules per shot of soft x rays at λ<0.5 nm from multiple micropinches well aligned along the axis of symmetry. When viewed end‐on the pinch appears as a small source of 700 μm diam. The micropinches have the following characteristics: Range of size 40–250 μm (depending on radiation wavelength), density 1028 m−3, temperature 1.5 keV, and lifetime typically less than 1 ns. The helium‐like emission from single micropinches lasts for 250 ps only, which is much shorter than previously reported.