Laser spectroscopy collinear

As discussed in the preceeding section, an extensive investigation of the rare-earth region is being performed by collinear laser spectroscopy. It includes a two-dimensional mapping of the (N, Z)-plane, covering not only scattered isotopic sequences but isotopes of a range of elements. 

As mentioned above, the radon and radium sequences have been investigated by collinear fast-beam laser spectroscopy, whereas in francium all three atomic-beam methods, ABMR, atomic-beam laser spectroscopy and collinear laser spectroscopy, have contributed. 

Several groups at ISOLDE are planning further improvements of their techniques. For each element the most appropriate experimental scheme has to be found. Today, collinear laser spectroscopy is the most general high-resolution and sensitive method for optical spectroscopy on radioactive beams delivered by on-line mass separators. Its sensitivity ranges from 10 - 10 atoms/s depending on the strength and multiplicity of the optical transitions. 

When working on line with a mass separator, such as Isolde, the collinear laser spectroscopy is a method fully adapted. In a collaboration Orsay - Mainz, the second members of the principal series in francium have been located and studied at high resolution with this method. In table 1 the measured wavenumbers of the four lines are given. 

The schematic view of the Mainz apparatus for collinear laser spectroscopy, installed at Isolde is given in fig 4. The 60 keV ion beam is set collinear with the laser beam, then accelerated (or decelerated) and finally neutralized in charge exchange cell. By Doppler tuning the atomic absorption is set resonnant with the stabilized laser frequency, and the fluorescence emitted is detected. 

In order to improve the signal-to-noise ratio in collinear laser spectroscopy, an ion source with bunched beam release was tested successfully. For this purpose, the temperature of a cold trap" inside the ion source is reduced for storage of reaction products, which are released from the trap during a subsequent period of increased temperature. The release of indium was found to occur with a FWHM of approximately 0.5s, corresponding to a... 

J. Eberz et al., "Collinear Laser Spectroscopy on l08fr)108mIn Using an Ion Source with Bunched Beam Release", to be published. 

The development of collinear laser spectroscopy has enabled measurements of isotope shifts and hyperfme stmcture over long chains of isotopes. This makes it possible to derive nuclear properties of isotopes far from stability. The experimental development is reviewed and some future prospects discussed. 

Figure 1. Schematic experimental set-up for coincidence collinear laser spectroscopy.

J. Eberz, et al. Collinear laser spectroscopy of using an ion source... 

Figure 9. Chart of the nuclides with optically investigated chains of unstable isotopes marked by solid frames Techniques other than collinear laser spectroscopy (see Table 1) were applied (partly) for Na, K, Ca, (Rb), Sr, Cd, (Sn), (Cs), (Ba), (Eu), (Hg), Pb, and (Fr)...

Anton, K.-R., Kaufman, W., Moruzzi, G., Neugart, R., Often, E.-W., and Schinzler, E. (1978). Collinear laser spectroscopy on fast atomic beams. Physical Review Letters, 40, 642-645. 

J. Eberz et al. Collinear laser spectroscopy o losgiosmin using an ion source with bunched beam release. Z. Physik A 328, 119 (1986)... 

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