A research team at the University of Innsbruck's Department of Ion Physics and Applied Physics successfully stored electrically charged helium nanodroplets in an ion trap for up to one minute. This achievement extends the experimental observation window by a factor of 10,000 compared to previous methods, enabling new research possibilities in basic physics and chemistry.
Research Significance
Helium nanodroplets are ultracold clusters of helium atoms that simulate conditions found in space. They facilitate spectroscopic analyses of particles present in the interstellar medium directly in a laboratory setting. Previously, reaction and observation times were restricted to a few milliseconds, limited by the flight distance between the droplet source and a detector.
Key Findings and Future Plans
The extended storage time enables detailed investigations of processes occurring within the droplets. Initial analyses indicate that collisions with residual gas in the vacuum chamber and infrared-absorbing molecules, such as water, within the helium limit the droplets' lifetime. This understanding is considered crucial for optimizing the trap technology. Professor Lutz Schweikhard from the University of Greifswald contributed to the development and application of ion traps for this new device. The new experimental setup allows helium droplets to be captured and stored for several seconds, facilitating time-resolved investigations.
Upcoming Developments
The next phase of development involves integrating detection cylinders into the ion trap. This will enable measurement of passing, highly charged helium droplets via an induced signal, determining both their mass-to-charge ratio and individual charge. This capability aims to provide insights into the temporal development of charged helium droplets and support the creation of a new form of nanocalorimetry. Elisabeth Gruber received an FWF-ASTRA Award to further develop this technology.
The findings were published in Physical Review Letters, highlighting the potential of helium nanodroplets as an ultracold laboratory environment for future research.