The XUV Doppler Telescope (XDT)

We present an overview and instrumental details of the solar XUV Doppler Te lescope (XDT) launched in January 1998 with the S520CN-22 sounding rocket o f the Institute of Space and Astronautical Science. The XDT observes nearly single-temperature solar corona at 1.8 MK with angular resolution of appro ximate to 5 " pixel size, together with the ability to detect the coronal v elocity field with a full-Sun field of view. By use of normal incidence opt ics whose primary and secondary mirrors are coated with multilayer material s in two sectors, the XDT takes images of the Sun in a set of shorter and l onger wavelength bands around the Fe xiv 211.3 Angstrom emission line. Summ ation of a pair of images in the two bands provides an image of the 1.8 MK- corona while the difference between the two provides velocity images of the Fe xiv-emitting plasma. A brief description on the observation sequence to gether with the flight result is also given.