A method and apparatus combining Gamma Resonance Absorption, Gamma Resonance Fluorescence, Gamma Induced Photofission, Dual Beam Gamma Energy Absorptiometry modality in a single system for contraband detection/identification. Such contraband detection systems utilize novel proton beam target devices capable of generating single or multiple monoenergetic gamma ray beams used in detection/measurement of contraband, for simultaneous detection of multiple target objects in a single scan.