Resume

Hyperfine structure measurements in Kr II

“…Laser light was introduced collinearly into the vacuum system in order to utilize the kinematic compression effect [14] to obtain high spectral resolution. Line widths of about 150 MHz were obtained, reflecting the velocity spread in the ion beam.…”

The New Generation of Resonant Laser Ionization Mass Spectrometers: Becoming Competitive for Selective Atomic Ultra-Trace Determination?

“…Furthermore, the conservation of the longitudinal energy spread during acceleration leads to a corresponding reduction in velocity spread, which results in a typically 500-fold reduction of the residual Doppler-widths of the optical resonances as compared with an unaccelerated atomic ensemble. 40 Under ideal conditions, with these large shifts and narrow widths, predicted optical isotopic selectivity can be as high as 10…”

“…60 The efficiency is increased in this way to about 10 -6 , still somewhat below the performance of competing techniques. Nevertheless, an optical selectivity of 2 × 10 5 for 41 Ca with respect to the major stable isotope 40 Ca is generated by partial compensation of the optical Doppler broadening by an anti-collinear arrangement of laser beams (see Figure 5). This leads to an overall selectivity of >10 10 .…”

Spectroscopy of molecular ions: Laser induced predissociation of O 2 +

“…Though common pulsed dye lasers cannot match the spectral resolution available with cw-laser systems, typical pulsed dyelaser line widths of a few tenths of a cm -1 are sufficient to investigate the rotational structure of smaller molecular ions. With a further realistic reduction of pulsed dye-laser linewidth to below 0.1 cm -1 one can take advantage of the "kinematic compression" [14] in a fast ion beam which reduces the absorption line widths to below the Doppler width. It must also be noted that a low temperature of the ions is very advantageous as it affects the population of the rotational (and vibrational) states thus enhancing the intensity of the spectral lines originating from one specific state and reducing the complexity of the spectra.…”

“…Furthermore, due to the spectral laser band width of 100 MHz or less the lifetimes of many single, predissociating rotational states could be determined from the observed line broadening [9,11,12]. In addition, by analyzing the initial kinetic energies released into the fragments, the predissociating states and dissociation limits were clearely identified [13,14]. In this manner complete information about excited, predissociating states can be obtained, which shows the significance of the method.…”