ATOMIC PHOTOEFFECT BELOW 100 KEV - AN OVERVIEW AND FUTURE SCOPE

The atomic photoeffect is a very important mechanism of photon interac tion with matter,especially below 100 keV, and most of the experimenta l data on photoelectric interaction is concentrated in this energy reg ion. In spite of the availability of a huge amount of data, large disc repancies are observed in cross-sections close to the absorption edges and particularly on the high energy side. The K-absorption edges coul d be easily studied using transmission experiments by selecting the en ergies, in either of two ways. First, photon energies could be selecte d as close to the edge as possible so that the experimental cross-sect ions would give a possible clue to the extended X-ray absorption fine structure which is seen on the high energy side of the K-edge, Secondl y, one can choose a wider photon energy region to cover at least three times the shell binding energy so that more distant cross-section val ues help to predict the trends of the cross-section curve with more ce rtainty. In the present study, the advantages of such a method, method s of experimental procedures, and difficulties in experimentation are presented. (C) 1997 Elsevier Science Ltd. All rights reserved.