Stopping power molecular

Methods of Calculating the Molecular Stopping Power and Its Properties... 

The ratio SJn = se characterizes the stopping power corresponding to one molecule and is called the molecular stopping power (it is measured in eVcm2 per molecule). For electrons, the expression for Se is usually presented in the form5... 

The principal parameter characterizing the molecular stopping power in Bethe s theory is the average ionization potential Im, which depends only on the properties of the molecule. There are different ways of... 

In formulas (5.2) and (5.4) the quantity lM enters the logarithmic term, which changes only slightly when we vary the value of IM if lmv2l - f 2) > IM. Thus, in the case of the fast particles, the chemical bond has a weak effect on molecular stopping power, and Bragg s rule works well. 

If the charged particle is a nucleus with no electron shells around it, the molecular stopping power depends on the velocity of the particle in the following way. At relativistic velocities v = c, the dependence of Se on v is determined by the logarithmic term in the brackets, because at v- c the factor preceding the brackets tends to some finite limit. So the molecular stopping power experiences the so-called relativistic rise. As for Se, its relativistic rise in real dense media is slowed down by the density effect (see Section V.B.2). 

Fig. 11. Molecular stopping power of water for protons (curve 1, data of Ref. 159) and electrons (curve 2 -----, data of Ref. 161 ----, data of Ref. 160).

For a given constituent, the stopping power is proportional to the product of molecular stopping power and molecular concentration ... 

The molecular stopping power is equal to the sum of atomic stopping powers. These in turn are commonly considered to be proportional to the atomic numbers. 

Here Z is the charge of the projectile with velocity v. In order to calculate stopping powers for atomic and molecular targets with reliability, however, one must choose a one-electron basis set appropriate for calculation of the generalized oscillator strength distribution (GOSD). The development of reasonable criteria for the choice of a reliable basis for such calculations is the concern of this paper. 

A major advantage of the orbital decomposition scheme of the KT is its ability to deal with orbital contributions to Se from molecular targets. This virtue has been particularly useful to theoretically analyze [25,33,40,41] the origin of the experimentally observed chemical binding effects and physical phase-state effects in the stopping power of light ions in compounds in the gas or in the condensed phase [20-24]. 

When the velocity of a particle becomes smaller than those of molecular electrons of a given shell, the latter no longer takes part in the retardation. This slows down the rise of the retardation power occurring at small velocities. At a certain velocity this effect becomes dominant, and as v decreases further, the stopping power also decreases. In the... 

Chemical bond effects on the low-energy electronic stopping power of protons use of molecular fragments. ... 

Here fhe symbols L and refer fo the orientation of the projectile beam with respect to the molecular plane. As only excitations with polarization perpendicular to the projectile velocity can contribute to the stopping power [21], and because we will generally place the molecules considered here in the xy-plane, the projectiles moving perpendicular to the plane are described by Ig and Ig while those moving in the molecular plane are described by either Ig and Ig or by Ig and Ig. The perpendicular and parallel components of the stopping power of a molecule placed in the xy-plane can then be expressed as... 

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