Asymmetry ratio in pair production and the degree of linearly polarized photons at intermediate energies

In order to initiate the experiments using linearly polarized tagged photon s at intermediate energies, it is imperative to know and to monitor the deg ree of polarization. The relationship is re-examined between the linear pol arization of photons and the asymmetry ratio in pair production by such pho tons. An improved method is proposed in which pairs are prohibited from ent ering the cone region around the incident photon beam. By restricting the d irections of pairs, the asymmetry ratio is much improved. (C) 1999 Elsevier Science B.V. All rights reserved.