scholarly journals Isotope shift in the resonance line of magnesium

1936 ◽  
Vol 154 (883) ◽  
pp. 679-683 ◽  
Keyword(s):  
Emission Line ◽  
Hyperfine Structure ◽  
Atomic Beam ◽  
Resonance Line ◽  
Isotope Shift ◽  
Wave Length ◽  
Spectral Lines ◽  
The Other ◽  
Absorption Lines ◽  
Doppler Width

By making use of an atomic beam instead of an ordinary gas or vapour, it is possible to observe structures of spectral lines very much smaller than the normal Doppler width. The structure of resonance lines can thus be observed as fine absorption lines on the background of the emission line possessing the full Doppler width. This method was used by the present authors for the detection and measurement of the hyperfine structure of the resonance lines of potassium and sodium. The following paper gives an account of the investigation of the structure of the singlet resonance line (2852 A) of magnesium by the same method. The line was found to possess two components at a separation of 0.033 cm -1 , the component of longer wave-length being very much stronger than the other.

Hyperfine Structure and Isotope Shift in Er I by the Atomic-Beam Laser Spectroscopy

1990 ◽  
Vol 59 (9) ◽  
pp. 3148-3154 ◽  
Author(s):  
Wei Guo Jin ◽  
Takayoshi Horiguchi ◽  
Masanori Wakasugi ◽  
Yasukazu Yoshizawa
Keyword(s):  
Hyperfine Structure ◽  
Laser Spectroscopy ◽  
Atomic Beam ◽  
Isotope Shift ◽  
Beam Laser

The spherical Fabry—Perot interferometer as an instrument of high resolving power for use with external or with internal atomic beams

1961 ◽  
Vol 263 (1314) ◽  
pp. 289-308 ◽  
Keyword(s):  
High Resolution ◽  
Hyperfine Structure ◽  
Atomic Beam ◽  
Resonance Line ◽  
Resolving Power ◽  
Light Power ◽  
Line Structure ◽  
Fabry Perot ◽  
Atomic Beams ◽  
Very High

The spherical Fabry -Perot interferometer was designed by P. Connes as an instrument capable of realizing higher resolving power than the normal Fabry -Perot interferometer, by virtue of its greater light power at high resolution, and the much lower requirement with regard to accuracy of adjustment. The instrument has now been used successfully in the resolution of structure in the resonance line of the arc spectrum of barium; components with a separation of 2.0x 10 -3 cm -1 have been resolved; they were observed in the absorption produced by a Jackson -Kuhn atomic beam, of high collimation. The instrument has also been used for observing line structure with an absorbing atomic beam traversing the interior of the interferometer; by this means the amount of material required for observing hyperfine structure using an atomic beam , even with very high collimation, can be reduced to a few milligrams, or approximately 100 times less than that required with an atomic beam external to the interferometer, so that enriched isotopes, available in small quantities, can be used; alternatively, adequate absorption can be obtained with much higher collimations of the beam, and correspondingly improved limits of resolution.

scholarly journals The hyperfine structure of the resonance lines of potassium

1935 ◽  
Vol 148 (864) ◽  
pp. 335-352 ◽  
Keyword(s):  
Hyperfine Structure ◽  
Electric Fields ◽  
Doppler Effect ◽  
Wave Length ◽  
Atomic Weight ◽  
Absolute Temperature ◽  
Resolving Power ◽  
Doppler Width ◽  
Mean Velocity ◽  
Gas Kinetic Theory

The limit of resolving power which can be used in the investigation of the fine structure of a spectral line depends upon the half-value width of the components. In the absence of electric fields, magnetic fields or pressure broadening, the half-value width of a line is a function of the temperature and the molecular (or atomic) weight of the radiating gas. The molecules possess velocities in random directions, and, as a result of the Doppler effect, small variations occur in the wave-length of the radiation according to the velocity and direction of the radiating molecule, or atom. It can be shown by the gas kinetic theory that owing to this random Doppler effect the half-value width of a line is equal to approximately λ x 10 -6 x √θ/M, where M is the molecular, or atomic weight of the radiating substance and θ is its absolute temperature. The greatest resolving power which can be achieved is therefore equal to 10 6 x √M/θ. For a given substance M is constant and θ alone can be varied; and in order to resolve the finest separations it is necessary to make θ as small as possible. By making use of the sputtering of metals in the neighbourhood of a hollow cathode, Schueler was able to observe the spectra of atoms at the temperature of liquid air, the spectra obtained being of very great intensity although the vapour pressures of the metals at that temperature are vanishingly small. By this method he was able to resolve the resonance lines of sodium, finding each line to consist of two extremely close hyperfine structure components; the half width of the lines was rather less than half of that which it would be if the spectrum of sodium vapour, at very l;ow pressure, were observed. By this method it is therefore possible to reduce the half-value of lines of the more volatile metals by a factor of two, and of the less volatile metals by a factor of three. Unfortunately this appears to be the limit of the method. On account of the heat generated by the discharge and the losses due to heat conduction, a very great quantity of liquid air is consumed so that it is improbable that the temperature could be further reduced by cooling with liquid hydrogen. Moreover, even if this were possible, the Doppler width of the lines would only be reduced by an additional factor of two, the mean velocity of molecules decreasing as the square root of the temperature.

scholarly journals Untersuchung des 5p2P3/2-Terms im Silber I-Spektrum durch Resonanzstreuung von Licht in elektrischen und magnetischen Feldern

1971 ◽  
Vol 26 (6) ◽  
pp. 1016-1020 ◽  
Author(s):  
H. Bucka ◽  
D. Einfeld ◽  
J. Ney ◽  
J. Wilken
Keyword(s):  
Hyperfine Structure ◽  
Electric Fields ◽  
Atomic Beam ◽  
Resonance Line ◽  
Positive Sign ◽  
Level Crossing

Abstract Using separated isotopes the hyperfine structure of the 5p 2P3/2-state in Ag I-spectrum was investigated by scattering the resonance line on an atomic beam in parallel magnetic and electric fields. With the theoretical positive sign of the Stark-constant β, the shift of the Heydenburg- and level-crossing-signals with electric fields can be explained by the following parameters: Ag (107) : A = - (32,4 ± 0.5) Mc/sec , Ag (109): A - - (37,3 ± 0.8) Mc/sec , β (2P3/2) = (5.15 ± 0.15) (kc/sec) (kV/cm) -2 , τ (2p3/2) = (6.3 ± 0.6 ) · 10-9 sec.

scholarly journals The spark-spectra of indium and gallium in the extreme ultra-violet region

1925 ◽  
Vol 107 (741) ◽  
pp. 138-156 ◽  
Keyword(s):  
Wave Length ◽  
Ultra Violet ◽  
Spectral Lines ◽  
The Other ◽  
Pressure Tubing ◽  
Quartz Spectrograph ◽  
One Stop ◽  
The One ◽  
Gas Tight ◽  
Concave Grating

The spark-spectrum of indium in the ultra-violet has been especially studied by Saunders, that of gallium by Saunders and Klein. By the use of a one-metre concave grating, mounted in a brass tube which could be exhausted, Saunders was able to extend the indium spark-spectrum as far below into the ultra-violet as λ = 1699 A. U. The line of shortest wave-length as yet noted in the gallium spark-spectrum—namely, λ = 2176 A. U.—was measured by Klein with a large quartz spectrograph whose mounting was of the Littrow type. With the object in view of making a complete and comprehensive examination of the spark-spectral lines of the above elements, that should extend right through the extreme ultra-violet and the quartz regions, the following investigations were undertaken. A.— Experiments in the Quartz Region . 1. Description of Apparatus .—For studying the spectra in the quartz region a spark chamber, diagrammatically shown in the figure, was employed. The spark chamber proper was a pyrex bulb about 7 inches in diameter. The terminals were of gallium and aluminium in the one experiment, and indium and aluminium in the other. Gallium has a very low melting point (30·2° C.). It was therefore placed in a tiny quartz cup, which, supported by a long aluminium rod, formed the lower terminal for the discharge. A piece of tungsten wire led from the aluminium support through the stem of the cup to the gallium. The upper electrode was of aluminium filed down to a point. Pieces of pressure tubing, 2 inches in length, lined with soft wax, fitted over the terminal supports and the tube elongations from the spark chamber. These formed gas-tight moveable joints, and served for the purpose of adjusting the spaek gap. The gap ranged from 2 to 3 mm. in width. The quartz window, through which the light passed into the spectrograph, was fastened to the spark chamber with sealing wax. One stop-cock led to the exhaust pumps, the other to the system of drying tubes. The spark was produced by a primary current of 110 volts ranging from 4 to 6 amperes. A Hilger Quartz-Prism Spectrograph, Type A, was used. All photographs were taken on Schumann plates.

The Ag I and Au I Resonance Line Broadening in Helium Plasma

2006 ◽  
Vol 61 (9) ◽  
pp. 491-498 ◽  
Author(s):  
Stevan Djeniže ◽  
Aleksandar Srećković ◽  
Srdjan Bukvić ◽  
Nikola Vitas
Keyword(s):  
Hyperfine Structure ◽  
Line Shape ◽  
Resonance Line ◽  
Plasma Source ◽  
Spectral Lines ◽  
Helium Plasma ◽  
Stark Broadening ◽  
Line Broadening ◽  
Temperature Estimation ◽  
And Shifts

The shapes and shifts of the resonance spectral lines of neutral silver (Ag I: 328.068 and 338.289 nm) and gold (Au I: 242.795 and 267.595 nm) have been measured in a laboratory helium plasma of about 18,500 K electron temperature and an electron density ranging between 0.78 · 1023 and 1.24 · 1023 m−3. Stark broadening has been found as the dominant mechanism of the line shape and position formation. Our measured Ag I and Au I resonance line Stark widths (W) and shifts (d) are the first reliable experimental data. They are compared with calculated single Ag I and Au IW and d data based on a semiclassical approach. The measured values are higher than the calculated ones, especially of the Au I resonance lines. Besides, we have calculated the hyperfine structure (hfs) components and their relative intensities of the mentioned Ag I and Au I lines. Strong asymmetry between the red and blue components of the hfs was found. A modified version of the linear, low-pressure, pulsed arc was used as plasma source operated in helium with silver and gold atoms as impurities, evaporated from silver and gold cylindrical plates located in the homogeneous part of the discharge providing conditions free of self-absorption. At the above mentioned helium plasma conditions the splitting in the hyperfine structure (Δhfs) of the Ag I and Au I resonance lines has been overpowered by Stark and Doppler broadenings. We estimate that at electron densities below 1020 m−3 and electron temperatures below 10,000 K the hfs components in the 267.595 nm and 242.795 nm Au I lines play an important role in the line shape formation, and the resulting line profiles can be used for temperature estimation in optically thin plasmas

Sign in / Sign up

Export Citation Format

Share Document