The high-brightness
beam physics has been the major hot research topic in the advanced accelerator
physics community. A recent development of the photo-cathode injector
technology has greatly enhanced the beam-quality such that high-density
beams are readily be available. The technology has enriched many advanced
accelerator fields, for instance, in areas such as the plasma wake field
accelerator, the x-ray FEL accelerator and the Thomson x-ray accelerator.
Especially for the Thomson x-ray experiment, there is an immense need
for under 20 micron electron beam spot at the interaction point with
the high-intensity laser. This has been demonstrated successfully at
PLEIADES Livermore. We constructed an asymmetric triplet quads of high
remanence permanent magnet material to produce an unprecedented high
magnetic gradient field of 560T/m at the center. In addition to the
implementation of high-gradient PMQs, we have developed a high-precision
motion system enabling the focusing lens to work in a wide range of
beam energy through tuning of drift-spaces.