Related Experiment Video
Updated: Oct 19, 2025
10:04
Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes
Published on: May 26, 2014
13.0K
(e,2e) Partial Ionization Cross Sections for n-Butane.
Rajbeer Singh1, Satyendra Pal1
1Department of Physics, M. M. H. College, Ghaziabad-201001, UP, India.
The Journal of Physical Chemistry. A
|September 23, 2021
Summary
This study calculates electron impact ionization cross sections for n-butane (n-C4H10) using a semiempirical method. The findings provide crucial data for understanding ionization processes and their temperature dependence.
Area of Science:
- Atomic and Molecular Physics
- Plasma Science
- Chemical Physics
Background:
- Electron impact ionization is fundamental to understanding plasma chemistry and material modification.
- Accurate cross-section data for hydrocarbons like n-butane is essential for various applications.
- Previous models may lack precision for complex molecules.
Purpose of the Study:
- To calculate energy-dependent partial differential and integral ionization cross sections for n-butane (n-C4H10) via electron impact.
- To derive averaged secondary electron energies and ionization rate coefficients.
- To validate the revisited Jain-Khare semiempirical formulation.
Main Methods:
- Utilized a revisited Jain-Khare semiempirical formulation.
- Calculated partial differential and integral ionization cross sections.
- Incorporated Bethe analytical extrapolation up to 6 keV.
- Derived ionization rate coefficients using Maxwell-Boltzmann energy distributions.
Main Results:
- Computed energy-dependent partial differential and integral ionization cross sections for n-butane.
- Determined averaged secondary electron energies.
- Evaluated ionization rate coefficients as a function of temperature.
- Achieved satisfactory agreement with existing experimental and theoretical data.
Conclusions:
- The revisited Jain-Khare formulation provides accurate ionization cross sections for n-butane.
- The derived data is valuable for modeling electron-driven processes in n-butane containing systems.
- The study validates the semiempirical approach for complex hydrocarbon ionization.
Related Concept Videos
01:21Chemical Ionization (CI) Mass Spectrometry
1.0K
The molecular ion peak of a molecule in the mass spectrum provides vital information for molecular identification. However, conventional electron impact ionization can lead to the rapid dissociation of some molecular ions before they reach the detector. A milder ionization method is required to increase the lifetime of such ionized analyte molecules. Chemical ionization (CI) is a gas-phase protonation reaction useful for mass-analyzing analyte molecules that are easily protonated to yield the...
1.0K
01:24π Molecular Orbitals of 1,3-Butadiene
10.3K
Conjugated dienes have lower heats of hydrogenation than cumulated and isolated dienes, making them more stable. The enhanced stabilization of conjugated systems can be understood from their π molecular orbitals.
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
10.3K
01:29Mass Spectrometry: Branched Alkane Fragmentation
1.2K
This lesson delves into the mass spectrometry of branched alkane fragmentation. Branched alkanes possess secondary or tertiary carbon atoms, which generate relatively stable carbocations if the cleavage occurs at the branching point. The high stability of carbocations drives the instant fragmentation of branched alkanes. Accordingly, the branched alkane's molecular ion peak is very weak or invisible in the mass spectra, especially in comparison to a linear alkane.
1.2K
02:20Conformations of Butane
15.9K
Unlike ethane and propane that have only two major conformations, butane has more than two conformers. The staggered form of butane in which the bulky methyl groups on the two carbons are placed on opposite sides, that is, at a dihedral angle of 180°, is the lowest energy, most stable form — called the anti conformer. This conformation is stabilized due to the absence of steric repulsion between the largely spaced out methyl groups. The other two staggered conformations are...
15.9K
01:18Mass Spectrometry: Long-Chain Alkane Fragmentation
1.9K
The molecular ions of linear alkanes prefer to fragment at the carbon-carbon bond away from the end of the chain since the cleavage of an inner bond creates a stable carbocation and a stable radical. Consequently, the mass signals of linear alkanes feature intense peaks in the middle of the mass-to-charge ratio plot with weaker peaks on either end. The fragmentation of each carbon-carbon bond with the release of a methyl group in each splitting leads to prominent peaks in the mass spectra...
1.9K
01:14Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene
2.9K
Electrophilic addition of halogens to alkenes proceeds via a cyclic halonium ion to form a 1,2-dihalide or a vicinal dihalide.
2.9K