Soft X-ray space- and time-resolving polychromator for plasma diagnostics

In this paper we describe a polychromator which enables us to observe the time resolution of the spatial distribution of soft X-ray emissions from high temperature plasmas. The polychromator is based on the Rowland circle mount of a spherical grating. An assembly of a two-stage MCP and a fluorescent screen is used as a two-dimensional position-sensitive detector for images of various wavelengths. The images on the fluorescent screen are transferred to a charge-coupled device with a camera lens and read out with a rapid data acquisition system. The spatial distribution of Cu L emissions (about 0.95 keV) from a windowless X-ray tube has been obtained with a spectral resolution of about 5 eV.