Ujjwal K Baruah & ITER-India Team

ITER, ‘the way” in Latin, is one of the most ambitious, technologically complex mega-science projects in the world. The objective of the International Thermonuclear Experimental Reactor (ITER) is to demonstrate experimentally the feasibility of controlled nuclear fusion as an alternate source of virtually limitless and clean energy. Nuclear fusion is the process that has been powering our sun and stars since ages. If successful, it will lay the path for the world and India to address in a novel and noble way the ever-increasing energy demand for future generations.

When the nuclei of the two isotopes of Hydrogen, Deuterium (D) and Tritium (T), fast enough to overcome the Coulomb repulsion (both nuclei being positively charged), collide they fuse together to convert into a Helium nucleus and a neutron (Figure 1). The mass of the reactants slightly exceeds the combined mass of the products with the mass difference being released as energy following ΔE=Δmc2, the famous formula of Einstein. Each reaction produces 17.6 MeV of energy, 14.1 MeV of the neutron and 3.5 MeV of the He-4 nucleus. The energy generated can be converted into heat and finally, electricity, see Figure 2.

Deuterium is available from seawater and Tritium can be generated within the reactor by blankets containing lithium salts. Barely a gram of gaseous fuel is within the reactor at any given time (e.g., the input and exhaust approximately same at 30 milligrams/sec of D or T for a 1000 m3 reaction volume). The yield of the D-T fusion reactions is the highest and requires temperatures in excess of 100 million Kelvin.  At such temperatures the matter is fully ionized (and known as plasma, the 4^th state of matter)…read more on NOPR