Research project Experiments with beams of cold stored ions in DESIREE

Temperatures in the thin gas and dust between the stars in the universe can be as low as minus 270 degrees Celsius. Yet new molecules can be created there. How is this possible? Henning Schmidt’s research team is attempting to understand fundamental processes behind the formation of new stars.

Temperatures in the thin gas and dust between the stars in the universe can be as low as minus 270 degrees Celsius. Yet new molecules can be created there. How is this possible? Henning Schmidt’s research team is attempting to understand fundamental processes behind the formation of new stars.

High up in the Earth's atmosphere, so-called air spirits occur, which are a weather phenomenon consisting of a gigantic network of electric discharges with a lifetime of a many milliseconds giving rise to a varied range of visual shapes flickering in the night sky. Using the Swedish National Infrastructure, DESIREE, located at Stockholm University, the study was led by Senior Lecturer Rich Thomas and PhD student Mathias Poline at the physics department of SU, and in a collaboration with the US Air Force Office of Scientific Research.

Using the unique DESIREE facility, researchers at Stockholm University and The Hebrew University of Jerusalem have for the first time been able to directly visualise the neutral products of the mutual neutralization of hydronium and hydroxide, and report three different product channels: two channels were attributed to a predominant electron-transfer mechanism, and a smaller channel was associated with proton transfer. The two-beam collision experiment is an important step toward understanding the quantum dynamics of this fundamental reaction. Their findings are published in the journal Science. A team of scientists led by Prof. Daniel Strasser at The Hebrew University in Israel joined with a team led by Dr. Richard Thomas at The Department of Physics at Stockholm University, to investigate this reaction using the DESIREE facility.

One reaction involving atomic and molecular ions which is extremely difficult to measure and explore in detail is mutual neutralisation, where a positive ion and a negative ion meet up, and neutralise. Thanks to a unique ion storage ring device, DESIREE, in Stockholm Sweden, these oppositely charged ions can be stored and controlled, then merged together in a cryogenically cold environment where the MN reaction happens. Using a cutting edge camera, we identify the reaction products and reconstruct the moment these opposites became fatally attracted, and neutralised.

An international collaboration led by Mark H. Stockett (Fysikum) and James N. Bull (University of East Anglia) last week published results from experiments conducted at the DESIREE infrastructure at Fysikum in Nature Communications. After decades of speculation and searching, astronomers have recently begun to identify complex Polycyclic Aromatic Hydrocarbon (PAH) molecules in interstellar clouds.