Correlation between Time-Resolved Soft X-Ray Images and Interferometric Results in a Plasma Focus

A time-resolved soft X-ray pinhole camera equipped with a microchannel plate as an image sensor was successfully developed for observation of a rapidly-changing plasma produced by a plasma focus device. Simultaneous observation with the pinhole camera and a Mach-Zehnder interferometer was carried out. This observation showed that the soft X-rays are emitted from the collapse phase to the disruption of the plasma focus. A high-intensity spot of the soft X-rays is recognized just before the disruption of the plasma column. In spite of the higher resistivity of the plasma column, it is found that the soft X-ray emission is not intense after the disruption. This comes from the rapid decrease of the electron density in this phase.