Assoc. Prof. Dr. Dimitar Lefterov graduated in Experimental Nuclear Physics at the Polytechnic Institute in St. Petersburg, Russia. He specialized in the Institute of Atomic Energy "I. V. Kurchatov ”in Moscow and at the Research Center in Julich, Germany. He was an expert of the International Atomic Energy Agency - Vienna. Associate member of the Institute for Nuclear Research and Nuclear Energy at the Bulgarian Academy of Sciences. He is a specialist in the field of semiconductor detectors for nuclear radiation and nuclear spectroscopy. He is the author of many scientific publications and a number of popular science articles.