The present invention discloses single crystal based phoswich detector for discriminating various kinds of radiations. The invented phoswich detector comprises a single crystal based scintillator having at least a pair of single crystals with identical refractive indices and different scintillation kinetics and a photo-sensor coupled to the single crystal based scintillator to detect a scintillation light pulse generated through interaction of radiation elements with the pair of the single crystals for discrimination of different kinds of radiation elements based on a dissimilarity in the scintillation light pulse shapes generated through the interactions.