Yohkoh scientific instrumentation included a Hard X-ray Telescope
(HXT), a Soft X-ray Telescope (SXT), a Bragg Crystal Spectrometer (BCS),
and a Wide-Band Spectrometer (WBS). These instruments are described
in a series of papers in
Solar Physics, vol. 136 (1991).
First results have been published in
Publ. Astron. Soc. Japan,
vol 44 (1992).
A bibliography of Yohkoh-related publications may be found at
http://www.lmsal.com/~aschwand/publications/yohkoh.html (or
its copy as of 20150417).
Yohkoh steadily continued its observation more than ten years, and
this made Yohkoh the world's first space mission to provide solar images
over a whole solar cycle. On 14-Dec-2001, however, observing an annular
eclipse, Yohkoh lost its attitude control and became unable to
resume observations.
Signals from the Yohkoh satellite were kept monitored for
more than 2 years after the end of scientific operation.
On 12-Sep-2005, Yohkoh re-entered the earth and burned out
in the atomoshpere somewhere above the point (24N, 85E).
Here are some more information about Yohkoh mission, spacecraft, and instruments.