Resonance profile

Figure 1 Schematic iiiustration of resonant profiling technique. In (a), the incident...

Determination of concentration profiles from the raw data can be more complicated when protons are used as the incident particles. The energy loss ( dE/ die) is smaller for protons and straggling effects are more important. The observed profile A (AJ)) is a convolution of the actual concentration profile C x with a depth resolution function (x, Eq), which broadens with increasing x roughly as Jx- Hence, resolution deteriorates with depth. However, near-surface resolution for resonant profiling may be on the order of tens of A. 

I. Vickridge and G. Amsel. Nucl. Instr. Meth. B45, 6, 1990. Presentation of the PC program SPACES, used in fitting spectra from narrow resonance profiling. A companion article includes fturther applications. 

Figure 4.2 Visual explanation of the effect of the constant background phase shift 8b on the resonance profile as a function of the phase shift 8(E) when it increases from 8b to 8b + jt. The partial-wave cross section 07(E) proportional to sin2 8(E) shows a symmetric peak for 8b = 0 and a symmetric dip for 8b = rr/2 since d<5(E)/d is symmetric with respect to Er, and an asymmetric profile with a peak and a dip for 8b = 7t/4. See text.

Fig. 3. Schematic illustration of nuclear resonance profiling. The sample surface is to the left. The particle energy continuously decreases from left to right as the projectiles pass through the material. The resonance energy ER is reached at a certain depth dR where the reaction takes place.

During the course of laser resonance experiments it was noticed that the central wavelengths shift depending on the helium density. Thus, the resonance line shapes at various target gas conditions were measured precisely with a reduced laser bandwidth and an improved wavelength calibration [18]. Figure 5 shows resonance profiles taken for the 597.26 nm line at different pressures ranging from 530 mb to 8.0 bar at temperatures of 5.8-6.3 K. The results are summarized in Table 2. 

Fig. 5. Resonance profiles of the 597.26-nm line showing red-shifts of the center with helium density. The linear scale for the y axes is not the same for different target conditions. From Torii et al. [18]...

The results of the pressure shift measurements on the two transitions (see Fig. 5) are presented in Table 2. There is a distinct difference between the (39,35) —> (38,34) and (37,34) —> (36,33) transitions. The presence of pressure shifts and broadening in resonance profiles is a well known general phenomenon. The present finding in pHe+ differs somewhat from usual in that the pressure shift is small (and with a substantial (n, l) dependence), and that the broadening is much smaller than the shift, while in ordinary atoms and molecules Ar is observed to be comparable to Av. 

Fig. 4. Two-laser microwave triple resonance experiment explained at the example of the already observed (n, L) = (37,35) — (38,34) transition. Left Simulated delayed annihilation time spectra of the laser/microwave triple resonance method. Right Simulated laser and microwave resonance profiles...

Moreover, for the MEF signal to be observable, it is also necessary that the local field enhancement at the laser fiequency loc( /,) is sufficiently large. Since and follow approximately the same resonant profile,... 

The MEF spectrum is in general affected by both resonance profiles Q icOg) and... 

As in the case of the artificial photo-absorption spectrum above, the spectrum cr E) features characteristic resonance profiles from which the positions and widths of all states, represented in the initial wave packet, can be extracted. If (0) overlaps with all eigenstates in a broad energy range, the entire spectrum can be recovered in a single calculation. In practical applications, the exponential operator (the propagator) in Eq. (14) is... 

Figure 13 Calculated absorption-type spectrum for DCO. Energy normalization is such that E = 0 corresponds to D-I-CO with CO at equilibrium. The dotted line marks the quantum mechanical threshold and the numbers indicate the pure CO stretching states (0, U2,0). There are 29 bound states. Because of the logarithmic scale, the Lorentzian resonance profiles have an unusual shape. Reproduced, with permission of the American Institute of Physics, from Ref. 15.

The partition of end groups and side branches between the crystalline and amorphous phases in polyethylene is determined by isolating the backbone resonances corresponding to the pure crystalline and amorphous phases by assuming as follows (1) the backbone methylene resonance profile may be used to separate the contribution from the crystalline and amorphous phases ... 

This table was derived from empirical data on conductivity and magnetism in solids. The shaded area maps the first order Mott transition between localised and itinerant behaviour in the solid, and the elements which lie on it have sensitive (e.g. pressure-dependent) properties. However, they are also remarkable in atomic physics for their giant resonances, are noted catalysts, or provide good materials for H storage, and then exhibit photon-stimulated desorption peaks which replicate the giant resonance profiles. Many of these properties seem to depend on the critical localisation of / and d electrons. 

From equation (12.10), one finds that interference between the direct bremsstrahlung process and polarisation radiation results in an asymmetry of the giant resonance profile observed in fluorescence with electron excitation even when the corresponding photoabsorption profile is symmetrical. This is exactly analogous to the Fano resonances (chapter 6) bremsstrahlung plays the role of the continuum, while the resonant chan-... 

This glitch is caused by interaction between the cavity and the sample resonance profiles. It may be converted into an apparent frequency shift of the cavity resonance that is directly related to the absolute absorption coefficient. The linewidth can be determined fi-om the distance between the peaks of the glitch. This phenomenon became even more marked with the Mark II confocal Fabry-Perot cavity (Section 5.3), when it could be observed as a glitch in the correction voltage applied by the servo amplifier to the piezoelectric actuator of the moveable cavity mirror. Figure 4.7 shows a spectrum for the water line obtained in this manner. 

In this paper, the spin exchange experiments, which employ the Dante sequence, are used to probe the resonance profile of those carbons which lie in an 0.7-1.0 nm sphere surrounding the resonance perturbed by the Dante sequence. A detailed description of the method and a consideration of the spatial extent of spin exchange (or spin diffusion) as a function of time are beyond the scope of this paper. Such information may be found in a forthcoming paper (32). In the present paper the Dante sequence will be viewed as a method for very selectively perturbing the Zeeman spin population within a multiplet. spin exchange in cellulose will be looked upon... 

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