Spectroscopy beam magnetic resonance

Quadrupole coupling constants for molecules are usually determined from the hyperfine structure of pure rotational spectra or from electric-beam and magnetic-beam resonance spectroscopies. Nuclear magnetic resonance, electron spin resonance and Mossbauer spectroscopies are also routes to the property. There is a large amount of experimental data for and halogen-substituted molecules. Less data is available for deuterium because the nuclear quadrupole is small. 

Hyperfine structure measurements using on-line atomic-beam techniques are of great importance in the systematic study of spins and moments of nuclei far from beta-stability. We will discuss the atomic-beam magnetic resonance (ABMR) method, and laser spectroscopy methods based on crossed-beam geometry with a collimated thermal atomic-beam and collinear geometry with a fast atomic-beam. Selected results from the extensive measurements at the ISOLDE facility at CERN will be presented. 

Molecular nitrogen, N2, is one of the most extensively studied diatomic molecules and optical spectroscopy has provided a wealth of information about its ground and excited electronic states. Molecular beam magnetic resonance studies of N2 in its ground state have yielded information about 14N nuclear spin dipolar and quadrupole interactions. Similar studies of N2 in its electronically excited A 3LU state were described in two very extensive papers by Freund, Miller, De Santis and Lurio [43] (paper I) and De Santis, Lurio, Miller and Freund [44] (paper II). We will describe their results and analysis in detail, but first note in passing that, strictly speaking, the lowest excited triplet state should be labelled the a state the label A has been used by all concerned in the past, so we will continue to do so. 

The origins and history of Spectroscopy with coherent radiation is reviewed from the earliest molecular beam magnetic resonance experiments up to the development of the laser. 

Thermal atomic beams have been used extensively to determine nuclear spins and moments by investigations of the atomic hyperfine structure. The atomic-beam magnetic resonance (ABMR) method has already become classical [2]. More recent efforts include laser spectroscopy in a crossed-beam geometry, in which a large supression of the Doppler width is obtained by collimation of the atomic beam. 

Millimeter wave spectroscopy with a free space cell such as a Broida oven is more sensitive than lower frequency microwave spectroscopy. However, the higher J transitions monitored by millimeter wave spectroscopy often do not show the effects of hyperfine structure. In the case of CaOH and SrOH, the proton hyperfine structure was measured in beautiful pump-probe microwave optical double resonance experiments in the Steimle group [24,68], They adapted the classic atomic beam magnetic resonance experiments to work with a pulsed laser vaporization source and replaced the microwave fields in the A and C regions by optical fields (Fig. 15). These sensitive, high-precision measurements yielded a very small value for the proton Fermi contact parameter (bF), consistent with ionic bonding and a... 

Various spectroscopic techniques of atomic, molecular and solid-state physics are employed in order to obtain experimental NQCC values such as atomic and molecular beam magnetic resonance, optical and rotational spectroscopy, nuclear quadrupol resonance (NQR) in solids or nuclear magnetic resonance (NMR). Atoms containing /u or tt mesons... 

S. Penselin Recent developments and results of the atomic beam magnetic resonance method, in Progress in Atomic Spectroscopy, Pt.A, ed. by W. Hanle, H. Kleinpoppen (Plenum, New York 1979) p.463... 

Meth DR LA LM MB MW QB RA method of measurement applied to obtain the reported values double resonance experiments (MODR and RFDR, compare 2.2.1) Doppler free laser spectroscopy Laser magnetic resonance molecular beam electric resonance or molecular beam resonance with laser detection microwave spectroscopy quantum beat spectroscopy radio astronomy... 

Figure 10.16 shows a block diagram of the whole apparatus, used by PEN-SELIN and his group for atomic beam magnetic resonance spectroscopy detected by laser-induced fluorescence [10.27e]. The pump laser beam crosses the atomic beam several times to assure high pumping efficiency. The rf tran-... 

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