Photoelectron spectroscopy of supersonic molecular beams

Technical Report · Sat May 01 04:00:00 EDT 1982

DOI:https://doi.org/10.2172/5287564· OSTI ID:5287564

Pollard, J E

A new technique for performing high resolution molecular photoelectron spectroscopy is described, beginning with its conceptual development, through the construction of a prototypal apparatus, to the initial applications on a particularly favorable molecular system. The distinguishing features of this technique are: (1) the introduction of the sample in the form of a collimated supersonic molecular beam; and (2) the use of an electrostatic deflection energy analyzer which is carefully optimized in terms of sensitivity and resolution. This combination makes it possible to obtain photoelectron spectra at a new level of detail for many small molecules. Three experiments are described which rely on the capability to perform rotationally-resolved photoelectron spectroscopy on the hydrogen molecule and its isotopes. The first is a measurement of the ionic vibrational and rotational spectroscopic constants and the vibrationally-selected photoionization cross sections. The second is a determination of the photoelectron asymmetry parameter, ..beta.., for selected rotational transitions. The third is an investigation of the rotational relaxation in a free jet expansion, using photoelectron spectroscopy as a probe of the rotational state population distributions. In the closing chapter an assessment is made of the successes and limitations of the technique, and an indication is given of areas for further improvement in future spectrometers.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5287564
• Report Number(s): LBL-14285; ON: DE82016940
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ASYMMETRY
BEAM ANALYZERS
BEAMS
CHARGED PARTICLES
CROSS SECTIONS
DEUTERIDES
DEUTERIUM
DEUTERIUM COMPOUNDS
ELECTRON SPECTROSCOPY
ELECTROSTATIC ANALYZERS
ELEMENTS
ENERGY LEVELS
ENERGY-LEVEL DENSITY
ENERGY-LEVEL TRANSITIONS
EQUIPMENT
EXCITED STATES
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN DEUTERIDE
HYDROGEN ISOTOPES
IONIZATION
IONS
ISOTOPES
LIGHT NUCLEI
MOLECULAR BEAMS
MOLECULAR IONS
NONMETALS
NUCLEI
ODD-ODD NUCLEI
PHOTOELECTRON SPECTROSCOPY
PHOTOIONIZATION
RELAXATION
RESOLUTION
ROTATIONAL STATES
SENSITIVITY
SPECTROSCOPY
STABLE ISOTOPES
VIBRATIONAL STATES