Photoionization Dynamics in Pure Helium Droplets

PDF Version Also Available for Download.

Description

The photoionization and photoelectron spectroscopy of pure He droplets are investigated at photon energies between 24.6 eV (the ionization energy of He) and 28 eV. Time-of-flight mass spectra and photoelectron images were obtained at a series of molecular beam source temperatures and pressures to assess the effect of droplet size on the photoionization dynamics. At source temperatures below 16 K, the photoelectron images are dominated by fast electrons produced via direct ionization of He atoms, with a small contribution from very slow electrons with kinetic energies below 1 meV arising from an indirect mechanism. The fast photoelectrons have as much ... continued below

Creation Information

Peterka, Darcy S.; Kim, Jeong Hyun; Wang, Chia C.; Poisson,Lionel & Neumark, Daniel M. February 4, 2007.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Sponsor

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

The photoionization and photoelectron spectroscopy of pure He droplets are investigated at photon energies between 24.6 eV (the ionization energy of He) and 28 eV. Time-of-flight mass spectra and photoelectron images were obtained at a series of molecular beam source temperatures and pressures to assess the effect of droplet size on the photoionization dynamics. At source temperatures below 16 K, the photoelectron images are dominated by fast electrons produced via direct ionization of He atoms, with a small contribution from very slow electrons with kinetic energies below 1 meV arising from an indirect mechanism. The fast photoelectrons have as much as 0.5 eV more kinetic energy than those from atomic He at the same photon energy. This result is interpreted and simulated within the context of a 'dimer model', in which one assumes vertical ionization from two nearest neighbor He atoms to the attractive region of the He2+ potential energy curve. Possible mechanism for the slow electrons, which were also seen at energies below IE(He), are discussed, including vibrational autoionizaton of Rydberg states comprising an electron weakly bound to the surface of a large HeN+ core.

Source

  • Journal Name: Journal of Physical Chemistry; Journal Volume: 111; Journal Issue: 31; Related Information: Journal Publication Date: 2007

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: LBNL--62405
  • Grant Number: DE-AC02-05CH11231
  • Office of Scientific & Technical Information Report Number: 920170
  • Archival Resource Key: ark:/67531/metadc900443

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • February 4, 2007

Added to The UNT Digital Library

  • Sept. 27, 2016, 1:39 a.m.

Description Last Updated

  • Sept. 21, 2017, 3:54 p.m.

Usage Statistics

When was this article last used?

Congratulations! It looks like you are the first person to view this item online.

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Peterka, Darcy S.; Kim, Jeong Hyun; Wang, Chia C.; Poisson,Lionel & Neumark, Daniel M. Photoionization Dynamics in Pure Helium Droplets, article, February 4, 2007; Berkeley, California. (digital.library.unt.edu/ark:/67531/metadc900443/: accessed September 26, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.