Atomic Oscillator Strengths in the Vacuum Ultraviolet
نویسندگان
چکیده
We have developed techniques to measure branching fractions in the vacuum ultraviolet using diffraction grating spectroscopy and phosphor image plates as detectors. These techniques have been used to measure branching fractions in Fe II that give prominent emission lines in astrophysical objects.
منابع مشابه
ar X iv : a st ro - p h / 00 07 23 6 v 1 1 7 Ju l 2 00 0 Empirical Verification of the Fe II Oscillator Strengths in the FUSE Bandpass
We report empirical determinations of atomic oscillator strengths, or f -values, for 11 groundstate transitions of Fe II in the wavelength range 1050 . λ . 1150 Å. We use ultraviolet absorption line observations of interstellar material towards stars in the Galaxy and the Magellanic Clouds taken with Copernicus, the Goddard High Resolution Spectrograph on-board the Hubble Space Telescope, and t...
متن کاملOxygen Isotopic Fractionation in Vacuum Ultraviolet Photodissociation of Co: Lack of Self-shielding and Relevance to the Early Solar System
Introduction: Isotopically selective photodissociation of CO at vacuum ultraviolet (VUV) wavelengths has been invoked as a photochemical process in interstellar molecular clouds to explain the observed abundance variation of minor isotopologues of CO [1-2], a process known as isotopic self-shielding (SS). Isotopic SS of CO within the nebular disk has also been advocated as the source of isotopi...
متن کاملبررسی ویژگیهای قدرت خط و نیروی نوسانگر اتمهای نقره و طلا با استفاده از نظریه تقریب کولنی
Single-valence electron atoms are an important class of atoms. Their oscillator strengths are their important properties. Knowing the oscillator strengths one can easity calculate the transition probabilities of the spectral lines and hence the lifetimes of energy levels of most atoms. The oscillator strengths of the spectral lines of most atoms are not knoen with sufficient accuracy due to t...
متن کاملVacuum-ultraviolet plasma Frenkel excitons: elementary excitations of polymerized fullerene
The high-frequency excitations of the molecular insulator C60 are investigated theoretically. The model of a quantum well rolled into a sphere is used to calculate the dipole ~multipole in the general case! modes of an individual C60 cluster. If the spectrum and oscillator strengths of the collective modes of an individual cluster are known, the microscopic continuum approach can be used to cal...
متن کاملVacuum Ultraviolet Optical Analysis of Spin-Cast Chitosan Films Modified by Succinic Anhydride and Glycidyl Phenyl Ether
Optical properties of spin-cast chitosan films were determined in the vacuum ultraviolet (VUV) through visible regions of the spectrum using spectroscopic ellipsometry. The onset of absorption in the ultraviolet was determined for chitosan films modified with succinic anhydride (SA) and glycidyl phenyl ether (GPE). This absorption was accounted for by including Gaussian and Tauc– Lorentz shaped...
متن کامل