Related Experiment Video
Updated: Jul 25, 2026
09:40
Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown
Published on: February 14, 2014
Neutral helium spectral lines in dense plasmas.
Banaz Omar1, Sibylle Günter, August Wierling
1Universität Rostock, Institut für Physik, Germany.
Summary
This study investigates helium spectral line shifts and broadening in dense plasmas. Electronic and ionic interactions were analyzed using quantum statistical theory, showing good agreement with experimental data.
Area of Science:
- Atomic physics
- Plasma spectroscopy
- Quantum mechanics
Background:
- Dense plasmas exhibit unique spectral line characteristics.
- Understanding spectral line shifts and broadening is crucial for plasma diagnostics.
Purpose of the Study:
- To investigate the shift and broadening of isolated neutral helium lines in dense plasma.
- To analyze electronic and ionic contributions to spectral line profiles.
Main Methods:
- Quantum statistical theory and thermodynamic Green functions were employed.
- Dynamic screening of electron-atom interactions was included.
- Quasi-static approximation considered ionic contributions, including quadratic Stark and quadrupole effects.
Main Results:
- Electronic contributions to spectral line shift and width were calculated.
- Dynamic screening significantly affects the electronic shift, especially at high densities.
- The study achieved good agreement between theoretical results and experimental/available data.
Conclusions:
- The theoretical model accurately predicts helium spectral line profiles in dense plasmas.
- Dynamic screening plays a critical role in electronic shifts.
- The findings contribute to accurate plasma characterization through spectroscopy.
Related Concept Videos
02:39Emission Spectra
When solids, liquids, or condensed gases are heated sufficiently, they radiate some of the excess energy as light. Photons produced in this manner have a range of energies, and thereby produce a continuous spectrum in which an unbroken series of wavelengths is present.
02:54Noble Gases
The elements in group 18 are noble gases (helium, neon, argon, krypton, xenon, and radon). They earned the name “noble” because they were assumed to be nonreactive since they have filled valence shells. In 1962, Dr. Neil Bartlett at the University of British Columbia proved this assumption to be false.
02:45Nuclear Fusion
The process of converting very light nuclei into heavier nuclei is also accompanied by the conversion of mass into large amounts of energy, a process called fusion. The principal source of energy in the sun is a net fusion reaction in which four hydrogen nuclei fuse and ultimately produce one helium nucleus and two positrons.
A helium nucleus has a mass that is 0.7% less than that of four hydrogen nuclei; this lost mass is converted into energy during the fusion. This reaction produces about...
A helium nucleus has a mass that is 0.7% less than that of four hydrogen nuclei; this lost mass is converted into energy during the fusion. This reaction produces about...
01:15High-Resolution Mass Spectrometry (HRMS)
The resolution of a mass spectrometer depends on the efficiency of separating ions with different ion masses. The mass of an atom is approximated to the sum of the masses of protons and neutrons inside, considering the masses of protons and neutrons as equal. However, the masses of the proton (1.6726 × 10−24 g) and neutron (1.6749 × 10−24 g) are not truly equal. There is a minor error in the expression of atomic masses relative to the simplest atom of hydrogen. For example, the mass of helium...
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
01:29Atomic Emission Spectroscopy: Lab
AES is a powerful analytical technique, especially effective when used with plasma sources, producing abundant spectra in characteristic emission lines. The Inductively Coupled Plasma (ICP), in particular, yields superior quantitative analytical data due to its high stability, low noise, low background, and minimal interferences under optimal experimental conditions. However, newer air-operated microwave sources are emerging as promising alternatives that could be more cost-effective than...