1. Chairman, Science & Technology Advisory Committee, ITER Council, (2007____).
2. Invited Speaker, AAAS Symposium on Magnetic Fusion, Boston (Feb.2008).
3. Invited Speaker, World Conf. on Science, Venice, (June 2007).
4. Member, International Fusion Research Council, IAEA, Vienna (1986-2000).
5. Chairman, International Fusion Research Council, IAEA, Vienna (2000-2007).
6. Artsimovitch Memorial Lecturer at IAEA Fusion Energy Conference , 1992.
7. Invited lecturer at APS Centennial Conference, Atlanta, Georgia, 1999.
8. Invited by NRC-NSF Panel Chaired by CF Kennel to make presentation on
   International impact of USDOE Fusion Theory programme, San Diego.
9. Associate and Corresponding Member, ICTP, Trieste, Italy.
10. Associate Editor, Jr. Plasma Physics (Cambridge) (1994-2006).
11. Past editorial assignments : Editorial Board, Plasma Physics & Controlled Fusion,
    I.O.P. U.K. (upto 1997). Correspondent, Comments in Plasma Physics, Physics
    News, Editorial Board, Pramana, Indian, Jr. of Physics.
12. National Lecturer in India (1973-74).
13. Japan Society for Promotion of Science, Visiting Professor (1974 and 2000).