Alignment orientation

The functions % to X4 correspond to orbitals having preferential alignments oriented towards the vertices of an circumscribed tetrahedron. Their combinations with the wave functions of four hydrogen atoms placed in these vertices yield the following functions, the insignificant coefficient c3 being neglected ... 

Figure 5. RBS spectra obtained from near random and aligned orientations for pulsed-laser annealed, As ion-implanted Si. (Reproduced, with permission, from Ref. 46. Copyright 1981, Journal of Applied Physics.,)...

Fig. 5.3. Scheme of excitation and observation for alignment - orientation conversion due to external perturbation. 

The prerequisite for the creation of orientation in the aligned state can also be formulated in terms of the time reversal properties of a Hamiltonian operator which represents the perturbation. As is shown in [276, 277] the alignment-orientation conversion may only take place if the time invariant Hamiltonian is involved. For instance, the Hamiltonian operator of the linear Zeeman effect is odd under time reversal and is thus not able to effect the conversion, whilst the operator of the quadratic Stark effect is even under time reversal and, as a consequence, the quadratic Stark effect can produce alignment-orientation conversion. 

The E-vector action of a sufficiently intensive light, which may be considered as a source of the dynamic Stark effect (us 7 0) can also induce orientation of particles. Such alignment-orientation conversion in the depopulated ground state in the presence of a magnetic field will be discussed in Section 5.5... 

An interesting possibility of meeting the conditions (5.42) and thus observing alignment-orientation conversion appears when the quadratic contribution to the Zeeman energy (4.53) is taken into account. In particular, the term connected with the non-spherical part of the diamagnetic suscep-... 

Fig. 6.6. Schematic of realization of alignment-orientation Stark conversion, (a) Choice of coordinate systems, (b) Possible realization scheme for AB molecules seeded in a free jet of X atoms, (c) Symbolic polar plot of J distribution (dashed line refers to initial cylindrical symmetry over beam axis z ).

If polar diatomic molecules are previously aligned in a beam (see Section 6.2) there is another possibility, proposed in [43], of producing angular momenta orientation using alignment-orientation conversion in a homogeneous electric field due to the second-order Stark effect (see Section 5.4). We will consider this method in more detail since it is a nice example of how to make use of handling the different approaches presented in Chapter 5 simultaneously. 

Fig. 6.8. Alignment-orientation conversion parameter k dependence on electric field strength as calculated for a 23Na39K (AXE) molecule (o) J = 10 (6) J = 11 (c) J = 100.

Pani, J. R., Jeffres, J. A., Shippey, G. T., and Schwartz, K. T., (1996). Imagining projective transformations aligned orientations in spatial organization. Cognitive Psychology, 31, 125-167. 

Auzinsh, M., A.V. Stolyarov, M. Tamanis, and R. Ferber, Magnetic field induced alignment - orientation conversion Non-linear energv shift and predissociation in Tc2 B 1 state, J. Chem. Phys., 105 p. 37 49 (1996). 

Finally, we should enquire as to whether or not it is reasonable to expect a linear response in describing the rotational diffusion of dipoles in the presence of a very strong local field, such as presented by the excess electron. The time window of the optical Kerr gate driven by a picosecond laser pulse depends on the relaxation of the molecules of the Kerr medium from an aligned orientation to an isotropic spatial distribution, once the applied optical field is switched off. For many liquids this relaxation time r is the low field limit, namely, the Debye time. We might anticipate an asynunetry in the temporal response 5 (0 of... 

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