Cross section photo transition

Particle-in-cell simulation, 154 Phonon stiffening, 36 Phonon-magnon coupled mode, 39 Photo-absorption cross section, 156 Photo-induced phase transitions, 42 Photo-nuclear activation, 173 PIC, 135... 

At 2000 K and 1 atm, Hollander s state-specific rate constant becomes k. = 1.46 x 1010 exp(-AE/kT) s-1, where AE is the energy required for ionization. For each n-manifold state the fraction ionized by collisions is determined, as well as the fraction transferred to nearby n-manifold states in steps of An = 1. Then the fractions ionized from these nearby n-manifold states are calculated. In this way a total overall ionization rate is evaluated for each photo-excited d state. The total ionization rate always exceeds the state-specific rate, since some of the Na atoms transferred by collisions to the nearby n-manifold states are subsequently ionized. Table I summarizes the values used for the state-specific cross sections and the derived overall ionization and quenching rate constants for each n-manifold state. The required optical transition, ionization, and quenching rates can now be incorporated in the rate equation model. Figure 2 compares the results of the model calculation with the experimental values. 

In analogy to (15.3.25) and (15.3.26) the functions Gi 2 can be related to the off-shell photo-absorption cross-sections with polarized photons and nucleons. There are four independent amphtudes, specified by the helicities of the virtual photon and nucleon the rest are related to these by parity and time-reversal invariance. Conventionally the four transitions are labelled by the total Jz involved and a label L or T to indicate a longitudinal photon (A, = 0) or a transverse photon (A-y = -1-1). The following is the pattern of transitions ... 

Fig. 10.4 View in polarized light of the cross section of a GGG crystal showing the transition from a convex to a flat interface. Photo reproduced from reference [5],...

Here one typieally adds in an imaginary component to a> (i.e., (o- (a + iy), to take into account the finite width of the electronic excited states due to quantum dephasing and vibronic relaxation. Under steady-state conditions, the absorption cross section, stimulated transition rate and the incident photo flux density, is determined by the imaginary part of ff(ct)) ... 

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