NOVELTY - Treating (M1) biomass involves directing charged particles having mass greater than or equal to the mass of a proton, and then directing charged particles on biomass material; generating charged particles, accelerating generated particles either by directing charged particles to make multiple passes through accelerator cavity having time-dependent electric field and multiple electrodes at different potentials, or by directing charged particles to pass through accelerator having multiple waveguides; and exposing biomass to accelerated particles.    USE - For treating biomass or for processing a petroleum-containing material comprising crude oil preferably crude oil being exposed to the ion beam before being refined, preferably crude oil being exposed to the ion beam before being refined (claimed); to produce useful products such as fuels, e.g. fuels for internal combustion engines, jet engines or feedstock for fuel cells.    ADVANTAGE - The method for treating biomass creates new useful matter without harmful environmental interference.    DETAILED DESCRIPTION - Treating (M1) biomass involves directing charged particles having a mass greater than or equal to the mass of a proton to pass through a fluid, and directing the charged particles to be incident on a biomass material; or generating several charged particles, accelerating the generated particles either by directing each of the charged particles to make multiple passes through an accelerator cavity comprising a time-dependent electric field and multiple electrodes at different potential, or accelerating several charged particles by directing the charged particles to pass through an accelerator comprising multiple waveguides, where each waveguide comprises an electromagnetic field; and exposing the biomass to the accelerated particles. An INDEPENDENT CLAIM is included for processing (M2) a petroleum-containing material that has been exposed to an ion beam to extract a hydrocarbon component from the petroleum-containing material.