Slow photoelectron velocity-map imaging spectroscopy of cold negative ions
Abstract
Anion slow photoelectron velocity-map imaging (SEVI) spectroscopy is a high-resolution variant of photoelectron spectroscopy used to study the electronic and geometric structure of atoms, molecules, and clusters. To benefit from the high resolution of SEVI when it is applied to molecular species, it is essential to reduce the internal temperature of the ions as much as possible. Here, we describe an experimental setup that combines a radio-frequency ion trap to store and cool ions with the high-resolution SEVI spectrometer. For C5–, we demonstrate ion temperatures down to 10 ± 2 K after extraction from the trap, as measured by the relative populations of the two anion spin-orbit states. Vibrational hot bands and sequence bands are completely suppressed, and peak widths as narrow as 4 cm−1 are seen due to cooling of the rotational degrees of freedom.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 26, 2012
- Source ID
- 10.1063/1.4772406
Entities
People
- Christian Hock
- Daniel Neumark
- Jongjin B. Kim
- Marissa L Weichman
- Tara I Yacovitch
Organizations
- Air Force Office of Scientific Research
- Lawrence Berkeley National Laboratory
- University of California