India’s India gyrotron SST-1 tokamak upgrade has taken a significant step forward with the installation and commissioning of an 82.6 GHz, 400 kW gyrotron at the Institute for Plasma Research (IPR) in Gandhinagar, Gujarat. The new device replaces the tokamak’s earlier 42 GHz heating system.
What the Gyrotron Does
SST-1, or the Steady State Superconducting Tokamak, is India’s experimental fusion machine, designed to study the process that powers stars. Scientists heat plasma, an electrically charged state of matter, to extraordinary temperatures and confine it inside a doughnut-shaped chamber using powerful magnetic fields. The gyrotron delivers high-frequency microwave energy directly into the plasma, helping heat and sustain it at these extreme conditions.
Why This Upgrade Matters
Indian fusion experiments have already produced plasma temperatures exceeding 200 million degrees Celsius, far hotter than the Sun’s core. But reaching high temperatures is only part of the challenge; sustaining hot, stable plasma for longer periods is just as critical. The new gyrotron is expected to strengthen research into exactly that: longer confinement and better plasma stability.
Not Yet Generating Electricity
Unlike the Sun, which relies on gravity to sustain fusion, Earth-based experiments depend entirely on magnetic confinement to keep plasma from striking the reactor walls. IPR has clarified that this development does not mean SST-1 is generating electricity; it remains a research step, not a power source.
India’s Broader Fusion Ambitions
The Institute for Plasma Research plays a central role in India’s participation in the international ITER fusion initiative and is working toward SST-2, a larger machine informally called India’s “DEMO” reactor. India’s Department of Atomic Energy has set a longer-term goal of building two 1,000 MWe grid-connected fusion reactors by 2050.

