Investigation of metal and metal oxide clusters small enough to constitute the critical size for gas phase nucleation in combustion processes. Final report, 1 October 1975-30 June 1979

Technical Report · Sat Nov 01 00:00:00 EST 1980

OSTI ID:5885775

Stein, G D

Over the course of this contract a variety of techniques have been employed to study the properties of small atomic and molecular clusters formed in the gas phase via homogeneous nucleation. The clustering occurs either in an adiabatic expansion of a condensable species (e.g. argon, krypton, xenon, or sulfur hexafluoride) in an inert carrier gas (e.g. helium), or as a mixing process using a hot condensable (e.g. lead, silver, copper, indium or bismuth) and a cold carrier gas (e.g. argon, helium, carbon dioxide or sulfur hexafluoride). A continuous development several types of cluster sources has been carried out and includes free jets, very small hypersonic laval nozzles, and a series of metal ovens with carrier gas mixing. Any one, of these sources, constitutes the first stage of a differentially pumped, molecular beam system which the produces a continuous beam of clusters. The denisty in the beam is so low that it is collisionless and thus the clusters do not interact with each other or with any other foreign molecule or surface. The study of these isolated clusters is carried out primarily using high energy electron beams (40 to 75 KeV). The resulting diffraction patterns are obtained either on film or through use of a single channel, scintillation, pulse counting system employing synchronous detection.

• Research Organization: Northwestern Univ., Evanston, IL (USA). Dept. of Mechanical and Nuclear Engineering
• DOE Contract Number: N00014-76-C-0378
• OSTI ID: 5885775
• Report Number(s): AD-A-093950
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
COMBUSTION
NUCLEATION
ADIABATIC PROCESSES
ELECTRON DIFFRACTION
FLUORINE COMPOUNDS
GASES
METALS
MOLECULAR BEAMS
MORPHOLOGY
RARE GASES
SILVER
SULFUR COMPOUNDS
BEAMS
CHEMICAL REACTIONS
COHERENT SCATTERING
DIFFRACTION
ELEMENTS
FLUIDS
HALOGEN COMPOUNDS
NONMETALS
OXIDATION
SCATTERING
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENTS
400800* - Combustion
Pyrolysis
& High-Temperature Chemistry