A solid state radiation detector comprises a substrate having a sensing element thereon and at least one heavy metal plug formed in at least one insulation layer above the substrate. The at least one heavy metal plug is located directly above the sensing element and is electrically isolated from the sensing element. The at least one heavy metal plug reacts with a plurality of initial radiation particles to produce a plurality of secondary particles, the plurality of secondary particles having a lower level of energy than the plurality of initial radiation particles; wherein the number of secondary particles produced is greater than the number of initial radiation particles with which the at least one heavy metal plug reacts; and wherein the sensing element is operable to produce an electrical signal in reaction to the secondary particles.