The x-ray spectrum of H-like uranium

By decelerating highly-charged, very heavy ions to low energies in the storage and cooler ring, ESR, a new brilliant source for projectile x-rays has been obtained. In a first precision spectroscopy experiment up to 2·10⁷ stored bare U⁹²⁺ ions have been decelerated down to 49 MeV/u before detecting the characteristic projectile x-rays associated with one-electron capture at the ESR gas target. The Lyman, Balmer and Paschen series are distinctly observed for hydrogenic U⁹¹⁺ ions.     

New interpretation of the AgL-series x-ray spectrum

Based on the de-excitation model of atomicL-shell vacancies, recent put forward by us, a new interpretation of Paratt's AgL x-ray spectrum has been successfully carried out, by using experimental and semiempiricalL ₁-hole decay data reported in recent years. An initialL-vacancy distributionN ₁:N ₂:N ₃=1:1.44:3.14 has been calculated from the silver spectrum. Present value of AgM-electron shakeoff probability due to anL-shell hole isP _M =0.034, which is much larger than theoretical calculations and semiempirical data.     

Proton-induced x-ray emission analysis of tea leaves

Proton-induced X-ray emission (PIXE) spectroscopy has been used for the determination of the concentration of 12 elements in tea leaves of four different brands. The elements are: Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br, Rb and Sr. The transference ratio of the elements into solution, when tea is leached by percolation is reported. It was found that some elements are totally transferred into solution and some are partially retained by the leaves. The significance of some of the elements found in the samples is discussed.     

K x-ray emission spectra from natural silicates

Chemical shifts of Si Kα_1,2 and Al Kα_1,2 lines in seven natural silicates has been measured comparatively to the lines of the pure elements. An attempt is made to correlate these shifts to the surroundings of Si and Al in the minerals.     

Vibrational interference effects in x-ray emission of a model water dimer: implications for the interpretation of the liquid spectrum

We apply the Kramers-Heisenberg formula to a model water dimer to discuss vibrational interference in the x-ray emission spectrum of the donor molecule for which the core-ionized potential energy surface is dissociative but bounded by the accepting molecule. A long core-hole lifetime leads to decay from Zundel-like, fully delocalized vibrational states in the intermediate potential without involvement of a specific dissociated component. Comparison is made to a model with an unbound intermediate state allowing dissociation to infinity which gives a sharp, fully dissociated feature, and a broad molecular peak at long core-hole life time. The implications of the vibrational interference effect on the liquid water spectrum are discussed and it is proposed that this mainly gives rise to an isotope-dependent asymmetrical broadening of the lone pair peak.     

Calculated Auger emission spectrum of ammonia

Doubly ionized states of ammonia are calculated with Roothaan's symmetry-restricted open-shell SCF method. A GTO basis of double-ζ quality is used. Calculated energies compare well with previous calculations for the lowest doubly ionized states. Auger emission intensities are estimated using an analogy with the experimental Auger spectrum of neon.     

The electronic emission spectrum of benzaldehyde vapour

The electronic emission spectrum of benzaldehyde vapour excited in a discharge consists mainly of ã³A″-X?¹A′ phosphorescence but also contains some weak ùA″-X?¹A′ fluorescence. The spectrum has been photographed under high resolution with a view to establishing which a″ vibrations are active in the ã-X? system. We have shown, with the help of rotational band contours, that the vibration in which the substituent as a whole moves out-of-plane is weakly active and that the substituent torsional vibration is more weakly active. These are the only a″ vibrations which are active with sufficient intensity to be observed in the spectrum.In the Ã-X? fluorescence an a″ wagging vibration of the hhydrogen atoms of the phenyl ring is moderately strongly active, as is the corresponding excited state vibration in the Ã-X? absorption system     

Excimer emission spectrum in noble gas systems

A simple expression for the time shape of excimer emission as a function of temperature is obtained for the case of a realistic (exponential) ground state potential. The excimer binding energy and its equilibrium geometry are obtained for the lowest ¹Σ_u states of Ar*₂, Kr*₂, Xe*₂ and for the A¹Σ_u and D¹Σ_u states of Hc*₂, by comparing the theoretical formula with the corresponding experamental results. Agreement with electronic calculations when available of these parameter is very good. The relation between our line-shape expression and those given by other authors is discussed.     

The vibration-rotation emission spectrum of gaseous HZnCl

Gaseous HZnCl has been synthesized for the first time in a high-temperature tube furnace with a dc discharge in a flowing mixture of pure HCl and Zn vapor. The vibration-rotation emission spectrum of HZnCl was recorded at high resolution using a Fourier transform spectrometer. The H-Zn stretching modes (nu(1)) of the H(64)Zn(35)Cl, H(66)Zn(35)Cl, H(68)Zn(35)Cl, and H(64)Zn(37)Cl species, as well as the 2nu(1)-nu(1) hot band of the most abundant isotopologue H(64)Zn(35)Cl, were observed near 1966 cm(-1). A least-squares fit was performed for each of the four observed isotopologues, and their spectroscopic constants were determined.     

Continued fraction description of density fluctuation spectrum in liquids

Abstract

So far many different approximate expressions of the density response have been proposed by using meanfield approximations and perturbative expansion methods. In this paper few of the these expressions are concisely stated by using generalized langevin equation approach.     

Determination of strontium coprecipitated with barium by x-ray emission spectroscopy

X-Ray emission spectroscopy allows detection of as little as 0.02%, strontium, in barium chromate. This method has been applied to evaluate the effectiveness of 4 procedures for separating barium and strontium by chromate precipitation. All of the procedures checked require at least 2 precipitations for a satisfactory separation. Of the 4 methods checked, that of beyer and rieman is recommended on the basis of convenience and effectiveness of separation.     

The vibration-rotation emission spectrum of hot BeF2

The high-resolution infrared emission spectrum of BeF2 vapor at 1000 degrees C was rotationally analyzed with the assistance of large-scale ab initio calculations using the coupled-cluster method including single and double excitations and perturbative inclusion of triple excitations, in conjunction with correlation-consistent basis sets up to quintuple-zeta quality. The nu3 fundamental band, the nu1+nu2, nu1+nu3, and 2nu2+nu3 combination bands, and 18 hot bands were assigned. The symmetric stretching (nu1), bending (nu2), and antisymmetric stretching (nu3) mode frequencies were determined to be 769.0943(2), 342.6145(3), and 1555.0480(1) cm-1, respectively, from the band origins of the nu3, nu1+nu3, and nu1+nu2 bands. The observed vibrational term values and B rotational constants were fitted simultaneously to an effective Hamiltonian model with Fermi resonance taken into account, and deperturbed equilibrium vibrational and rotational constants were obtained for BeF2. The equilibrium rotational constant (Be) was determined to be 0.235 354(41) cm-1, and the associated equilibrium bond distance (re) is 1.3730(1) A. The results of our ab initio calculations are in remarkably good agreement with those of our experiment, and the calculated value was 1.374 A for the equilibrium bond distance (re). As in the isoelectronic CO2 molecule, the Fermi resonance in BeF2 is very strong, and the interaction constant k122 was found to be 90.20(4) cm-1.     

A 3000 K laboratory emission spectrum of water

An emission spectrum of hot water with a temperature of about 3000 K is obtained using an oxy-acetylene torch. This spectrum contains a very large number of transitions. The spectrum, along with previous cooler laboratory emission spectra and an absorption spectrum recorded from a sunspot, is analyzed in the 500-2000 cm(-1) region. Use of a calculated variational linelist for water allows significant progress to be made on assigning transitions involving highly excited vibrational and rotational states. In particular emission from rotationally excited states up to J=42 and vibrational levels with up to eight quanta of bending motion are assigned.     

Electronic emission spectrum of p-fluorobenzaldehyde vapour

The high resolution electronic emission spectrum of p-fluorobenzaldehyde vapour excited in a discharge is reported for the first time. The spectrum consists of both the ã³A″?X?¹A′ phosphorescence and the ùA″?X?¹A′ fluorescence bands. Whereas all the eleven out-of-plane vibrations appear in the fluorescence spectrum, only the φ-CHO torsional vibration and the φ-CHO wagging vibration appear in the phosphorescence. A total of thirty ground state vibrational frequencies out of the thirty-six possible fundamentals have been obtained from the emission bands. Both the fluorescence and the phosphorescence emission spectra of p-fluorobenzaldehyde are very similar to those of benzaldehyde itself. This shows that the electronic transitions are not very sensitive to the substitution of fluorine at the para position of benzaldehyde.