Ionization and fragmentation of molecular gases in collisions with MeV/amu heavy ions

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5149898

Maurer, R J

A detailed study of ionization and fragmentation in molecular gas targets by 2.75 MeV H{sup +} and 40 MeV Ar{sup 13+} ions has been performed using the time-of-flight (TOF) method. Ionization of molecular gases by 2.75 MeV H{sup +} ions results primarily in single and double ionization, and consequently, the fragmentation patterns are simple to interpret. Energetic highly-charged, heavy ions, such as 40 MeV Ar{sup 13+}, were found to be very effective in producing multiple ionization in molecular gas targets either through direct ionization or electron capture. Multiply-charged molecular ions, which are typically very unstable, rapidly dissociated to yield a rich fragmentation pattern containing numerous atomic and molecular fragments. A two stage TOF mass spectrometer was designed, constructed and tested for application to the study of fragmentation in molecular gas targets. The fragmentation patterns for several molecular gases from simple diatomics (N{sub 2}, O{sub 2}, CO, NO) and triatomics (CO{sub 2}, N{sub 2}O, NO{sub 2}, SO{sub 2}) to large polyatomics (C{sub 2}F{sub 6}, C{sub 2}H{sub 4}F{sub 2}, SF{sub 6}) have been measured. The fragmentation patterns for molecular gases measured by the TOF method were found to be useful in providing information about the various pathways for unimolecular dissociation of multiply-charged molecular ions. Moreover, several useful quantities such as fragments yields and average kinetic energies were obtained from the TOF spectrum.

• Research Organization: Texas A and M Univ., College Station, TX (USA)
• OSTI ID: 5149898
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ARGON IONS
CALIBRATION
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON FLUORIDES
CARBON MONOXIDE
CARBON OXIDES
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
COLLISIONS
DESIGN
DISSOCIATION
ELEMENTS
ENERGY RANGE
FLUIDS
FLUORIDES
FLUORINE COMPOUNDS
FRAGMENTATION
GASES
HALIDES
HALOGEN COMPOUNDS
HYDROGEN IONS
HYDROGEN IONS 1 PLUS
ION COLLISIONS
ION-MOLECULE COLLISIONS
IONIZATION
IONS
MASS SPECTROMETERS
MEASURING INSTRUMENTS
MEV RANGE
MEV RANGE 01-10
MEV RANGE 10-100
MOLECULAR IONS
MOLECULE COLLISIONS
MOLECULES
MULTICHARGED IONS
NITRIC OXIDE
NITROGEN
NITROGEN COMPOUNDS
NITROGEN OXIDES
NITROUS OXIDE
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
SPECTROMETERS
SULFUR COMPOUNDS
SULFUR FLUORIDES
SULFUR OXIDES
TIME-OF-FLIGHT METHOD