Scientists Develop New Methods for Cooling of Ions    

Scientists from Bangalore and Mainz have demonstrated that captured ions can be cooled through contact with cold atoms and could be stored in so-called ion traps in a stable condition for longer periods of time. This finding runs counter to predictions that ions would actually be heated through collisions with atoms. The results have opened up the possibility of conducting chemical experiments to generate molecular ions at temperatures as low as those prevailing in interstellar space.

Scientists of the Raman Research Institute in the Bangalore in India and the Institute of Physics at Johannes Gutenberg University Mainz (JGU) in Germany captured neutral atoms in a magneto-optic trap, cooled them with laser light to a temperature close to absolute zero at minus 273.15 degrees Celsius, and also stored charged particles in an ion trap. For this purpose, Professor Dr. Günter Werth had to set a Paul trap as used in Mainz in India, where it was combined with a magneto-optic trap. It was thus possible to trap ions and cold atoms at one and the same location to observe their development.

The experiment with rubidium ions and rubidium atoms showed that the ions were effectively cooled during a collision with the cold atoms. “The expectation is that the interaction of ions and atoms at very low temperatures will result in the formation of molecular ions. This is a process that we believe also occurs in inter-stellar space," said Professor Werth.
Report in Nature Communications,