India is advancing nuclear fusion research in pursuit of an ambitious goal: harnessing the same fundamental process that powers the Sun and stars. Often described as an “artificial sun,” this effort centres on experimental facilities at the Institute for Plasma Research (IPR) in Gandhinagar, Gujarat, including the Steady State Superconducting Tokamak-1 (SST-1) and ADITYA-U. These machines investigate the conditions needed for future fusion reactors; they are not commercial electricity-generating plants.
How does an “artificial sun” work?
Nuclear fusion releases energy when light atomic nuclei combine to form heavier nuclei. Unlike conventional nuclear power, which relies on splitting heavy atoms through fission, fusion seeks to harness energy by joining them. Reproducing this process on Earth requires extremely high temperatures and sufficient confinement to keep the reacting particles together.
At these temperatures, the fuel becomes plasma—an electrically charged state of matter. A tokamak uses powerful magnetic fields to confine this plasma. India’s SST-1 employs superconducting magnets and specialised heating systems to help researchers study plasma stability, confinement and the challenges of sustained operation.
A significant heating-system advance
An important development is the integration of an 82.6-gigahertz, 400-kilowatt gyrotron with SST-1. A gyrotron produces powerful microwaves that transfer energy to electrons in the plasma, helping scientists heat it and investigate its behaviour. According to IPR, the system can deliver radio-frequency power in pulses lasting up to half a second. Crucially, 400 kilowatts refers to the heating device’s output—not electricity generated through fusion.
India’s work also extends beyond its domestic laboratories. As a partner in ITER, the international fusion experiment under construction in France, India contributes major components and engineering expertise. Its contributions include the enormous cryostat, which provides the cold, insulated environment needed around key reactor systems, along with cooling, cryogenic and diagnostic equipment.
Promise—and the challenges ahead
Fusion could eventually provide substantial low-carbon energy, with no carbon dioxide released by the fusion reaction itself. However, practical power plants require more than extremely hot plasma: researchers must achieve sustained confinement, develop materials that withstand harsh conditions and demonstrate reliable net electricity production.
India’s “artificial sun” is therefore best understood as a research programme building the knowledge and technology for future fusion energy—not an already functioning substitute for conventional power stations. Its significance lies in strengthening the scientific and engineering capabilities needed to turn the promise of fusion into a practical energy source.
