Interaction incoherent

Coherent interaction is called the dipoleJim e. The incoherent interaction that alters ihc momentum of an aiom is called the scntieruig /one. 

A similar conclusion was reached by Benatti and Floreani [114] with a density operator model for elementary particle decays, taking into account incoherent interactions with the environment. 

Fig. 2.6 Response of a two-level system to (a) a pulsed resonant laser-light field E t), (b) coherent interaction at 2 dE/K) > I/T2, and (c) incoherent interaction at 2 dE/h) I/T2 ri2 is the relative population of the excited level, and E is the light-field amplitude).

With the incoherent interaction approximation, the set of equations (2.59) is greatly simplified. In this case, the polarization P of the two-level system depends in a... 

However, in the case of incoherent interaction, the picture looks simpler, for there are no level population oscillations at all. In that case, to describe the evolution of level populations, use can be made as before of rate equations, such as eqn (2.61), but the quantities ni and ri2 should now be understood to be the total populations of each level. The difference in level populations given by eqn (2.48) should then be modified for naturally polarized light as follows ... 

The physics of the multistep excitation of atoms is, of course, much more profound than may be inferred from the simplest qualitative considerations given above. The whole picture can be found in the two-volume comprehensive monograph by Shore (1990). The approximation of incoherent interaction between a laser field and a real multilevel atom, described by rate equations, is quite acceptable (Ackerhalt and Eberly 1976), especially if account is taken of the degeneracy in the magnetic sublevels mp. Resonance transitions to various mp values differ in the projection of the dipole moment d 2, and hence in the Rabi oscillation frequency (eqn 2.44). This generally smooths out oscillations and makes the interaction incoherent. It is only in the ideal case of a two-level system free from level degeneracy that one can observe Rabi oscillations, as illustrated in Fig. 9.3. 

An incoherent ensemble of dipoles constitutes the usual source in astrophysics (or earth). These dipoles interact weakly with each other so that no... 

As in the case of the Rouse dynamics (see Sect. 3.1.1), the intermediate incoherent scattering law for dominant hydrodynamic interaction (Zimm model) can be... 

Comparing Eqs. (83), (84) and Eqs. (21), (22) it follows immediately that Rouse and Zimm relaxation result in completely different incoherent quasielastic scattering. These differences are revealed in the line shape of the dynamic structure factor or in the (3-parameter if Eq. (23) is applied, as well as in the structure and Q-dependence of the characteristic frequency. In the case of dominant hydrodynamic interaction, Q(Q) depends on the viscosity of the pure solvent, but on no molecular parameters and varies with the third power of Q, whereas with failing hydrodynamic interaction it is determined by the inverse of the friction per mean square segment length and varies with the fourth power of Q. 

Now, the decay rate of the incoherent dynamic structure factor is proportional to fc(i+2v)/v xherefore, the -dependence of the decay rate for salt-free solutions is independent of whether the hydrodynamic interaction is present or not. 

X-ray attenuation occurs via four basic modes of interaction, shown schematically in Figure 4. Coherent X-ray scatter (CXRS) is an energy preserving interaction between an X-ray photon and an entire atom or crystalline matrix. Incoherent or Compton scatter represents a direct interaction between an X-ray and an... 

Ruffle, S. V. Michalarias, I. Ei, ].-C. Ford, R. C. Inelastic Incoherent Neutron Scattering Studies of Water Interacting with Biological Macromolecules. /. Am. Chem. Soc. 2002, 124, 565-569. 

Figure 2.4 Different types of interactions of electrons with a solid 1, X-ray or optical photons 2, back-scattered electrons 3, secondary electrons 4, coherent elastic scattering 5, inelastic scattering 6, incoherent elastic scattering.

Figure 1. Incoherent Interference Control (IIC) scheme and potential energy curves for Na2- This scheme is composed of a 2 wi photon process proceeding from an initial state, assigned here as (v = 5, J = 37), via the u = 35, J = 36, 38 levels, belonging to the interacting A1 Xu /3nu electronic states, and a one 2 photon dresses the continuum with the (initially unpopulated) v = 93, J = 36 and v = 93, J = 38 levels of the A1 Xu /3H electronic states.

Coherent Nucleation. The elastic interaction between the strain field of the nucleus and the stress field in the matrix due to the dislocation provides the main catalyzing force for heterogeneous nucleation of coherent precipitates on dislocations. This elastic interaction is absent for incoherent precipitates. 

---