Electron hole competition factor

The scattering pattern contains additional information about the scattering process itself as well as for the determination of material parameters. We will demonstrate in the following, that both the angular dependence of the holographic gain and the product of the effective linear electro-optic coefficient with the electron-hole competition factor as well as the effective trap density can be determined from the spatial distribution of the scattering pattern as a function of temperature [7],... 

There is competition for the free electrons between the positrons and the holes (OH radicals in the case of water media). When OH competes for these free electrons the addition of OH scavengers is predicted to cause an increase in the yield of o-Ps, a phenomenon called enhancement . On the other hand, addition of electron scavengers will reduce the yield of o-Ps, an effect known as inhibition . The yield of o-Ps is usually denoted by I3 (where and I2 are the yields of free positrons and />-Ps, respectively, having a much shorter half-life than o-Ps). Duplatre and coworkers - found that the yield of o-Ps in aqueous solution in the presence of concentration C of allylamine is given by equation 10. The enhancement factor 1 -h )SC is due to the reaction of allylamine with OH radicals, while the 1 + C inhibition factor is due to the reaction with aqueous or free electrons. The enhancement by amines is one of the main pieces of evidence for the existence of the spur mechanism . Yet, it should be emphasized that it does not rule out the simultaneous existence of both mechanisms . Duplatre and coworkers found that the inhibition by a strong inhibitor such as NO3 is the same in the presence or absence of allylamine. 

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