Cross section, differential reaction Chapter

Up to now there has been no calculation of differential cross sections by a method that is generally valid. We use a formulation due to Konovalov (1993). Understanding of ionisation has advanced by an iterative process involving experiments and calculations that emphasise different aspects of the reaction. Kinematic regions have been found that are completely understood in the sense that absolute differential cross sections in detailed agreement with experiment can be calculated. These form the basis of a structure probe, electron momentum spectroscopy, that is extremely sensitive to one-electron and electron-correlation properties of the target ground state and observed states of the residual ion. It forms a test of unprecedented scope and sensitivity for structure calculations that is described in chapter 11. 

Using HRTOF crossed molecular beam technique, we studied the F( P) + D2 DF + D reaction systematically. The differential cross sections and the relative integral cross sections in this reaction were provided. We measured the F( P3/2)/ F ( Pi/2) r tio in the F atom beam and thus got the F( P3/2)/F ( Pi/2) reactivity ratio, which is in perfect agreement with the theoretical results. In Sect. 4.1 of this chapter, we review non-adiabatic efifects in the F -b H2 system the measurement of the F( P3/2)/F ( Pi/2) ratio in the F atom beam is described in Sects. 4.2, 4.3 presents the crossed molecular beam experimental results and discussion summary is given in the last section. 

The theoretical methods reviewed in the next chapters produce all of these quantities, ranging from state and energy selected differential cross sections to temperature dependent rate coefficients. Thus the theory of chemical reaction dynamics provides a crucial link between the results obtained in detailed state selective molecular beam experiments and thermally averaged bulb measurements. 

In addition, we have studied the initial state selected D-fH2(u = l,j) — DH+H reaction. For the first time, the initial vibrationally excited rate constant K=i T = 310 Jf) agrees quantitatively with experiment. Based on these D+H2 calculations, the H+H2 calculations in Chapter 2, and the recent D+H2 differential cross section calculations of Kuppermann and Wu [1] in their study of the gemetric phase effect, we conclude that many of the quantitative aspects of the H+H2 reaction (and isotopic analogues) on its ground electronic state are well understood. 

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