Life Sciences Division
Oak Ridge National Laboratory

Enhanced electron attachment to highly-excited molecules using a plasma mixing scheme

  Researchers in the Biochemistry and Biophysics Section of the Life Sciences Division have developed a novel plasma mixing technique to achieve enhanced electron attachment to highly-excited states of a variety of molecules. In this scheme, long-lived metastable states of inert gases are produced in a glow discharge and are extracted into an adjoining discharge-free region (target region); a suitable molecular gas is fed into the target region where they undergo excitation transfer from the inert gas metatstable states. The highly excited molecules thus produced attach slow electrons that are also extracted to the target region from the discharge region. Researchers observed negative ion formation in a variety of gases including methane, nitric oxide, and some fluorocarbons. In addition to the production of negative ions, this technique automatically leads to the formation of radicals (molecular fragments). The preliminary results were published in a paper by L.A.Pinnaduwage, W.Ding, and D.L.McCorkle, Applied Physics Letters , Vol. 71, p. 3634 (December 1997).

 This technique may have a variety of applications including, (1) an inexpensive negative ion (neutral beam) source, (2) the means to efficiently produce radicals for plasma processing of materials, and (3) the means to dissociate molecules in plasma remediation of volatile toxic compounds. Two patent disclosures have been filed regarding the last two applications.

Contact: Lal Pinnaduwage Phone: 574-6540
E-mail: LLP@ornl.gov