Isotope shift optical

In such a situation it is natural to invert the problem and to use the high accuracy of the optical measurements and isotope shift theory for determination of the difference of charge radii squared of the deuteron and proton. We obtain... 

In the optical spectroscopy experiments, data on the isotope shifts (IS) may be obtained in addition to those on the hfs. The important nuclear information on the changes of mean square charge radii, deduced from the IS results, will be discussed by Kluge at this symposium [KLU85]. 

Finally, for all of these cases, once accurate wave functions are available, they can be used to calculate a wide variety of atomic properties, such as oscillator strengths, multipole moments, long range interactions, etc. A great deal of work has been done in this area, some of which is reviewed in various chapters throughout the Atomic, Molecular, and Optical Physics Handbook [35]. A particularly fascinating example is the use of the lithium isotope shift to determine the nuclear radius of exotic halo nuclei such as 11 Li [75]... 

Photolysis of CO occurs by absorption of stellar UV radiation in the wavelength range 90-100 nm. The reaction proceeds by a predissociation mechanism, in which the excited electronic state lives long enough to have well-defined vibrational and rotational energy levels. As a consequence, the three isotopic species—C O, C O, and C O—absorb at different wavelengths, corresponding to the isotope shift in vibrational frequencies. Because of their different number densities, the abundant C O becomes optically thick in the outermost part of the cloud (nearest to the external source of UV radiation), while the... 

Let us assume that the anharmonicity constant A is large compared to the width T) = 2T (where T is the half-width) of the phonon band. In this case, as was shown in Subsection 6.2.2, the width of the biphonon band is of the order of T /A, i.e. small compared to the width T of the band of optical phonons. Important here is, however, the comparison of the width of the biexciton band with isotope shift. Indeed, in the limiting case of strong anharmonicity, the biphonon energy is E ss 2hui — 2A and the biphonon state 2) is just the coherent superposition of the states of two-fold excited molecules. It is clear then that an elementary generalization of an equation of the type (6.89) can be used to find biphonon local states. Specifically, the equation for the frequency of a local biphonon io, i.e. the localized state split off the biphonon zone, can be written as follows ... 

In astrophysics much interest has in recent years been focussed on boron. Although its cosmic abundance is extremely low, it plays an important role in testing models of Big Bang Nucleosynthesis [10]. Optical spectroscopy is the only method for establishing B abundances in stellar objects, and thus a good knowledge of energy structure, transition probabilities, hyperfine structure and isotope shifts is needed [11]. 

Laser spectroscopic studies of radioactive isotopes have proved to be a valuable source in obtaining nuclear properties. The continuing developments promise a way of meeting challenge in measuring nuclear properties far from stability. It may also be so that new isotopes are discovered by optical rather than nuclear methods. The extreme high precision measurements in ionic traps make rather small nuclear effects such as hype ne anomaly interesting for tx experimental and theoretical studies. In ad(Ution the theories of hyperfine structure and isotope shift are well understood, so that detailed information on nuclear properties can be extracted. 

The Breit-Rosenthal correction is found to account for a very small part of these observed anomalies Based on changes in the charge distribution, S r ) deduced from optical isotope shifts [62,56], together with the parameter X2 from Table I (and a factor of about 0.64 to account for the higher moments), we find that the Breit-Rosenthal contribution should be about —0.01 x 10 and —0.04 x 10 , respectively. 

Here, I will not discuss the hyperfine anomaly nor the additional important nuclear information on changes of mean square charge radii obtained from isotope shift (IS) data in optical experiments. 

The first hfs measurements in francium were made with the ABMR method, giving nuclear spin values for the sequence of isotopes - 5.22o-222pj. 2], These experiments were followed by atomic-beam laser experiments [23] which, after the identification of the Dj qitical line, gave results on the hypeifine structure constants in the 7s ground state and the 7p excited state as well as isotope shifts in 208-2i3Fr. Fuller measurements in francium include the nuclear spin of Fr, the nuclear g-factor of Fr and the electronic g-factor of francium by the ABMR method [13], the identification of the D, optical transition by atomic-beam laser spectroscopy [24], and the 7s —> 8p and 7s -> 8p Pj transitions... 

An interesting modification of optical excitation especially for the accurate determination of isotope shifts is a combination of resonance excitation / ionisation and a mass spectrometric analysis of the ions created as it is realized in RIMS (resonance ionization mass spectrom-... 

To study the stereochemistry of the hydrogen shift, optically active 1-deuterio-l-methyl-3- r -butylindene was found to give l- r -butyl-3-methylindene = 5.5) with optical and deuterium labeling consistent with a suprafacial deuterium shift (Scheme 10.4). Moreover, the primary deuterium kinetic isotope effect was roughly 3. 

In this section I hope to show how the sensitivity of laser spectroscopy is exploited to obtain data on very low concentrations of atoms. In particular I will start off by considering a few laser atomic beam studies aimed at measuring optical isotope shifts and show how short-lived nuclei can be studied in this way. I shall also mention how it is possible to beat the natural linewidth and obtain supernatural spectra . The discussion of laser studies at low atomic concentrations then leads me onto consider experiments on laser cooling and trapping of atoms and ions. In this context I will also mention some experiments using the shelved electron idea to detect very weak transitions. Finally, I will say something about Rydberg atoms and the effects of atoms near metallic surfaces. 

In most laser studies of optical isotope shifts the crossed, laser-atomic beam method is used to avoid Doppler-broadening. In some cases short-lived radioactive isotopes are detected directly on-line, in others, by irradiating a target which is subsequently heated to form the source of an atomic beam. Figure 7 shows a spectrum obtained some years ago in Oxford on the resonance line of barium at 554 nm S] ... 

The isotope-selective analysis by optical detection methods is almost impossible unless transitions with sufficiently large isotope shifts as observed with light and heavy elements are available. In contrast to traditional emission or absorption techniques the high-resolution laser spectroscopy enables Doppler-free measurements since the spectral linewidth of tunable CW lasers is commonly less than the Doppler profile... 

Charge distribution can be extracted firom the measurement of elastic electron scattering. X-rays from muonic and ordinary atoms (isotope shifts), and optical spectra (Fricke et al. 1995). 

Optical emission spectroscopy is routinely used for the determination of nitro-gen-15. The method depends upon the wavelength separation of the isotopic species of nitrogen gas ( N2, and due to the isotopic shift. 

This offers the great advantage of optical resonance with the whole ensemble of atoms and yields an extremely high sensitivity, if the fluorescence is detected with a large solid angle. This advantage, and the fact that on-line isotope separators deliver many radioactive nuclides in the form of ion beams, have played the decisive role for the success of this technique in studies of atomic isotope shifts and hyperfine structures. On the other hand, the high-resolution spectroscopy on ions has been provided with a powerful experimental tool. 

Similarly, the isotope shift of an optical transition is related to the change in the nuclear mean square charge radius between the... 

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