  A promising prototype of a highly adjustable Kirkpatrick-Baez (KB) microscope
has been designed, built and tested in a number of laser driven x-ray
experiments using the high power (200TW) VEGA-2 laser system of the Spanish
Centre for Pulsed Lasers (CLPU). The presented KB version consists of two,
perpendicularly mounted, 500{\mu}m thick Silicon wafers, coated with a few tens
of nm layer of Platinum unlike the conventional, coated, millimetre thick glass
substrates, affording more bending flexibility and large adjustment range.
According to simulations, and based on total external reflection, this KB
offers a broad-band multi-keV reflection spectra, allowing more spectral
tunablity than conventional Bragg crystals. In addition to be vacuum
compatible, the prototype is characterised by a relatively small size (21cm x
31cm x 27cm) and permits remote control and modification of both the radius of
curvature (down to 10m) and the grazing incidence angle (up to 60mrad). A few
examples of focusing performance tests, limitations and experimental campaign
results are discussed.
