Empirical relation for total stopping power of positons and electrons

Investigation of positron annihilation-in-flight using a digital coincidence Doppler broadening spectrometer

“…where a 1 and a 2 are material constants characterizing the absorber. For targets with Z 38, a 1 = −5.95 g −1 cm 2 keV, a 2 = 928 g −1 cm 2 keV, while for targets with Z > 38, a 1 = −2.85 g −1 cm 2 keV, a 2 = 810 g −1 cm 2 keV [19].…”

“…where N A is Avogadro's number and A is the atomic weight of the absorber. The positron stopping power S(E + ) was calculated in [19] taking into account energy losses in inelastic and elastic collisions and by bremsstrahlung radiation. The positron stopping power can be represented by a product of two functions which depend on the total energy of the positron (expressed in units of the rest electron mass) and the atomic number Z of the absorbing material:…”

Study the total Stopping Power of electrons in Beryllium

“…An extensively study [3][4][5][6][7][8][9][10][11] exists in the literatures ,Berger and Seltzer [4] had modified the Bethe -Heitler theory and introduced empirical corrections to calculate the mean energy loss by Bremsstrahlung .Btra [10] calculated the stopping power for positron with two parameter approximation and it is valid for positron energy between 1KeV-5000KeV ,besides its found that there a multiple scattering distribution which exhibits differences between β -and β + .…”

Stopping Power of Electrons and Positrons for C, Al, Cu, Ag, Au, Pb, Fe, U, Ge, Si and Mo

“…Estimation of the stopping power for electrons and positrons in matter from these analytical expressions is tedious and involves use of mean excitation and ionization energies. A considerable amount of empirical work has been done during the last few years [Batra, 1973;Batra, 1970;Gupta, 1982;Unak, 1995], on total stopping power of materials. Nuclear physics theorists can predict total stopping power, csda ranges and related properties very accurately.…”

“…These improvements depend heavily on new developments in empirical techniques, and to a greater extent on the insights gained through close collaborations between theorists and experimentalists doing research on physical properties of solids. Empirical concepts such as valence electron, ionic charge, atomic number, electro negativity and energy are then useful [Batra, 1973;Batra, 1970;Gupta, 1982;Unak, 1995;Akar, 2005;Gumus, 2005;Oller, 2006;Tanuma, 2008;Pauling, 1960;Verma, 2009;Verma, 2008]. These concepts are directly associated with the character of the chemical bond and thus provide means for explaining and classifying many basic properties of molecules and solids.…”