Indian scientists developed innovative technique for production of negative hydrogen ions


Indian scientists of the Centre of Plasma Physics – Institute for Plasma Research (CPP-IPR), Sonapur in cooperation with their colleagues from the Institute for Plasma Research, Gandhinagar developed an innovative technique for the production of negative hydrogen ions. Their finding are published in an article called ‘Development of a novel surface assisted volume negative hydrogen ion source’ in a reputed multidisciplinary scientific journal ‘Nature‘.

According to the article, negative hydrogen ions (H−ions) play an important role in many terrestrial as well as extra-terrestrial natural physical phenomena. “The negative ions are often used in many other industrial applications, such as in ion beam deposition studies, for micrometer-sized powder surface modification, damage-free nano-particle formation for quantum devices, bio-compatibility surface treatment in nerve cell engineering fields, tandem accelerators and high energetic Neutral beam injection system for fusion reactor,” it said.

The research was conducted by Dr. Siddhartha Sankar Kausik, Dr. Bharat Kakati and Dr. Bipul Kumar Saikia of CPP-IPR and Dr. Mainak Bandyopadhyay and Dr. Predhiman Krishan Kaw of IPR.

“Negative hydrogen ions have a wide variety of significant applications in thermonuclear fusion reactor for energy generation, particle accelerators, surface modifications and biomedical fields. Negative hydrogen ion-based NBI is one of the important methods to heat plasma inside the fusion reactor,” they told the Assam Tribune newspaper.

“However, the existing negative ion source configuration has limitations in terms of production, extraction etc. To overcome these limitations, an experiment based on a novel concept of surface-assisted volume negative ions production by sprinkling cesium coated tungsten dust grains into a hydrogen plasma has been carried out at CPP-IPR and this new concept has been successfully validated,” they added.

According to Dr. Kausik, the negative hydrogen ions are produced almost uniformly around the dust column and fill the plasma volume. As a result, it is not required to reverse the direction of these ions for extraction unlike conventional negative ion source.

“As the micron-sized cesium-coated tungsten dust is used as low-work function surface for negative hydrogen ion production, considering some advantages, the present source can be converted to a compact efficient ion source in future,” he said.

“Thermonuclear fusion has the potential to produce sufficient energy to satisfy the mounting demand of energy of modern world. For thermonuclear fusion, it is necessary to heat the plasma above hundred million degrees centigrade. To heat the plasma, high energetic neutral atoms are injected into the plasma with the help of NBI system,” the authors explain.

Centre of Plasma Physics – Institute for Plasma Research (CPP-IPR) is a research centre of Institute for Plasma Research (IPR), Gandhinagar, Gujarat. It is an autonomous institute under the Department of Atomic Energy (DAE).

The Centre of Plasma Physics was initially formed with a small group of scientists in 1991.