A radiation beam intensity modulation device constituted of: a control circuitry; a plurality of cells, each of the plurality of cells arranged, responsive to the control circuitry, to be switched between an attenuating state and a transparent state; and attenuating material, each of the plurality of cells arranged to contain therewithin a portion of the attenuating material when in the attenuating state and not contain therewithin the portion of the attenuating material when in the transparent state.