L-vacancy sharing

It is emphasized that this cancellation does not occur for L-vacancy sharing. With set II in Table 1, one obtains = 1.82Xj. from Eq. (36) where the index refers to the L shell. This exponent is in good agreement with the observation by Lennard et who studied extensively vacancy... 

Figure 14. Probability Wl for L-vacancy sharing as a function of the scaling parameter...

Figure 34 shows also experimental results obtained by Schneider et using the method of Auger spectroscopy. For the system S + Ar it is seen that the RAD(cr) process provides the major contribution to the Ar L excitation. However, for Si + Ar the RAD((r) process becomes less important. In this case an additional process different from vacancy sharing has to be considered. This process, analyzed by Wille, is attributed to the lS-2ir-4or rotational coupling mechanism (Figure 31). As expected the respective cross sections from this process, labeled ROT in Figure 34, are practically the same for the systems S + Ar and Si + Ar. On the contrary, with increasing asymmetry of the system the RAD(o-) process loses importance, since the energy gap between the L shells of the collision partners increases (Figure 31). Hence, it is concluded that pure L-vacancy sharing may be studied only in rather symmetric collision systems.

A powerful but short-lived color center laser is based on theFj center. As indicated in Fig. l,theFj center consists of two adjacent anion vacancies sharing one trapped electron. In contrast to the Fa,b(II) centers, the FJ relaxation... 

Figure 29. Vacancy sharing probabilities for the K and L shells in the systems B + Ar, C + Ar, N + Ar, and O + Ar as a function of the inverse projectile velocity. The data refer to the excitation of the lower-lying levels, i.e., the Ar i-shell orbitals for B -I- Ar and the K-shell orbitals of the lighter particle in the other systems. The dots refer to experimental results by Reed et al and the solid lines follow from three-state model calculations on the basis of the SHM matrix elements (18). The dashed line represents two-state calculations for O H- Ar by means of Nikitin s model." ...

Figure 34. Cross sections for Ar L excitation in the collision systems Si -t- Ar and S + Ar as a function of the projectile energy. The experimental data are from Schneider el The curve labeled ROT refers to 6-2v-A

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