*************************************************************************
   71151
   Among several known cluster radio haloes, we found one good candidate
   for the site of ultra-high-energy cosmic rays, a pair of shock fronts
   along the rim of A3667. They have outstanding characteristics as a
   cosmic accelerator: located at the rim where massive accretion is
   taking place, extending about 1 Mpc, their power index of radio
   emission very close to 1. We expect to find the first direct proof of
   the acceleration up to 10^20 eV in the cluster scale structure with
   ASCA.
 *************************************************************************