Doppler-tuning

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. 

Fig. 9. Doppler-tuned spectrum of the ls2s 1S o —ls2p 3Pi,f=2 and ls2s 1S o —ls2p 3Po transitions in 14N5+...

Abstract. Using Doppler-tuned fast-beam laser spectroscopy the ls2p 3Po - 3Pi fine structure interval in 24Mg10+ has been measured to be 833.133(15) cm-1. The calibration procedure used the intercombination ls2s 1So - ls2p 3Pi transition in 14N5+. The result tests quantum-electrodynamic and relativistic corrections to high precision calculations, which will be used to obtain a new value for the fine structure constant from the fine structure of helium. 

Fig. 3. Doppler tuned resonances of (a) the 24Mg10+ 2 3Po -2 3Pi fine structure transition, and of the 14N5+ 2 4So -2 3Pi,f=2 intercombination interval, obtained (b) before, and (c) after, the magnesium data. All resonances were obtained with the same 4 /rg cm-2 carbon foil...

Figure 11.46. (a) Recording of the 21,2 <— 17,1 vibration-rotation transition of the HD+ ion, obtained by Doppler tuning the ion beam into resonance with a carbon dioxide infrared laser beam [88], (b) A radiofrequency/infrared double resonance spectrum obtained by pumping the v3 line shown in the infrared spectrum (see text for the assignment). 

Fig. 10. Doppler-tuned spectrum of the ls2p Po — ls2p Pi transition in...

Abstract. Using Doppler-tuned fast-beam laser spectroscopy the ls2p Po - Pi fine structure interval in has been measured to be 833.133(15) cm . The cah-... 

Furthermore, as the atom slows down it would, in the absence of the magnetic field, Doppler tune itself out of resonance with the laser the specially designed solenoid prevents this happening by Zeeman tuning the atoms in synchronism with the velocity reduction i.e., the magnetic field in the direction of travel z of the atoms has the form ... 

An alternative method for overcoming the Doppler tuning problem in laser cooling has been demonstrated by Ertmer et al. 52] Instead of using a spatially varying magnetic field these authors controlled the frequency of the laser by means of an electro-optic modulator, driven by a radiofrequency source. Varying the frequency of the r.f. field applied produces sidebands to the laser frequency and these can be swept in step with the Doppler shift. 

Fig. 4.28 Arrangement for electric Doppler tuning applied to the spectroscopy of fast ionized or neutral species...

Fig. 4.30 Dependence of the 0+ photofragment signal on the absorption wavelength of Oj, obtained by Doppler tuning at a fixed laser wavelength [470]...

If several transitions are possible from level /) with frequencies a> within the Doppler tuning range... 

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