Yogendra Pathak Viyogi received the BSc and MSc degrees from Bihar University and then joined the 15th batch of Training School Programme of Bhabha Atomic Research Centre (BARC), Mumbai (1971). He was trained in experimental nuclear physics at BARC and at Lawrence Berkeley laboratory, USA. He moved to Kolkata to work at the Variable Energy Cyclotron Centre, a unit of the Department of Atomic Energy and obtained his PhD (1984) from the University of Calcutta. He was also a postdoctoral fellow at GANIL Laboratory in France (1984-86). He was Director of Institute of Physics, Bhubaneswar during June 2006-June 2009. He retired from service in Oct. 2012 as Outstanding Scientist at VECC Kolkata.
Presently he is working for the INO Project at Variable Energy Cyclotron Centre, Kolkata as DAE Raja Ramanna Fellow.
Academic and Research Achievements: At Berkeley, Viyogi was involved in the study of projectile fragmentation reactions involving intermediate energy heavy nuclei. He experimentally established the application of projectile fragmentation reactions to the production of exotic nuclei far from β-stability. This led to the development of radioactive ion beams, opening up new branches in nuclear physics. Since late eighties, he has been the involved in the study of quark gluon plasma at CERN in Geneva and Brookhaven National Laboratory in USA using an indigenously developed photon multiplicity detector (PMD), which has been a unique effort in large-scale instrumentation by a collaboration of physicists from six Indian universities/institutions led by him. The data from the maiden PMD led to the first observation of collective flow, supposedly a manifestation of thermalization in ultra-relativistic nuclear collisions. In addition, it has made significant contributions to the QGP physics through the study of formation of disoriented chiral condensates, a manifestation of chiral symmetry restoration, and critical phenomena leading to fluctuation in global observables. He was also instrumental in developing Bakelite RPC as alternative detector for the India-based Neutrino Observatory (INO) project. He has also mentored eight PhD students.
Other Contributions: As Director of Institute of Physics, Viyogi has played a lead role in the establishment of National Institute of Science Education and Research (NISER) at Bhubaneswar.
Besides physics activities, Viyogi has been writing popular essays on science, travelogue, short stories and plays in Maithili. These are being regularly published in various Maithili magazines. He has published three books in Maithili—(a) Vigyanak batkahi – a collection of essays on topics of science, (b) Kichhu Teet Madhur—travelogue based on foreign visits, and (c) Akta Misia – collection of short stories. He also mentors school students in science practical in his village in Madhubani district of Bihar.