Flash-freezing of molecular ions in a storage ring
Rapid rotational cooling of molecular ions by interaction with electrons has been observed for the first time in the TSR heavy ion storage ring of the Max Planck Institute for Nuclear Physics in Heidelberg.
This kind of laboratory astrophysics helps to understand in more detail the physical and chemical properties of cold interstellar matter.
The interaction of molecular ions with free electrons is of key importance to understand the physical and chemical properties of cold astrophysical environments like interstellar molecular clouds. Whereas electron-ion recombination has been studied in great detail in storage ring and ion trap experiments in the last two decades, information about the exchange of energy between slow electrons and the internal motion (rotation and vibration) of molecular ions was rather limited.
Researchers of the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg, of the Weizmann Institute of Science in Rehovot (Israel) and of three other collaborating institutions have now published first quantitative results for fast electron cooling of rotating singly charged HD molecular ions. In the TSR heavy ion storage ring of the MPIK an HD molecular ion beam was merged with cold electrons of 33 K (-240°C) temperature, i. e. 33 degrees above absolute zero.
The interaction with the electrons reduced the rotational temperature of the ions from initially about 1200°C to -150°C within only 8 seconds and stabilized it at this low value in the simultaneously acting thermal radiation field at the ambient room temperature (300 K). During the process, the ions pass the electron cooling bath about 175000 times per second. The cooling due to so-called superelastic collisions, where some amount of energy is transferred from the rotational motion of the ion to linear motion of the electron, is well described by theoretical calculations initiated through this experiment.
Prof. Dr. Andreas Wolf
Max Planck Institute for Nuclear Physics, Heidelberg
Prof. Dr. Daniel Zajfman
Weizmann Institute of Science, Rehovot, Israel
http://link.aps.org/doi/10.1103/PhysRevLett.102.223202 Orginal publication
http://www.mpi-hd.mpg.de/blaum/members/molecular-qd/index.en.html Group of Prof. Andreas Wolf
http://www.weizmann.ac.il/particle/molecule/ Group of Prof. Daniel Zajfman
Dr. Bernold Feuerstein | Max-Planck-Institut
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...