This paper proposes a new method for proton acceleration. A slow plasma wav
e produced by backward Raman scattering captures the injected protons. Dens
ity gradient of the plasma enables the wave-phase velocity to increase as t
he proton test beams are accelerated. Preliminary results of PIC simulation
s of the backward scattering and proton acceleration in a uniform plasma ar
e presented. (C) 2000 Elsevier Science B.V. All rights reserved.