(E,2E) MEASUREMENTS OF RARE GAS INNER-SHELL IONIZATION Birgit Lohmann#, A. Duguet=86, A. Lahmam-Bennani=86, I. Taouil=86, J.= Rasch=87, C. T. Whelan* and H. R. J. Walters=A7 #School of Science, Griffith University, Nathan Queensland 4111 AUSTRALIA =86Laboratoire des Collisions Atomiques et Mol=E9culaires, B=E2t. 351, Unive= rsit=E9 de Paris XI,=20 F-91405 Orsay Cedex FRANCE =87Institut de Physique, Universit=E9 de Metz, Rue Arago, 57078 Metz Cedex 3 FRANCE *Dept. of Applied Mathematics and Theoretical Physics, Cambridge University, CB3 9EW UK =A7Dept. of Applied Mathematics and Theoretical Physics, The Queen's University, Belfast BT7 1NN UK (e,2e) measurements for Ar(2p) ionization under highly asymmetric kinematics are presented. The kinematics correspond to a low momentum transfer of 0.5 a.u., however despite this the cross section is not symmetric about the momentum transfer direction, K. The results are compared with first Born and distorted wave Born approximation (DWBA) calculations. The two calculations both predict symmetry about K, in disagreement with what is experimentally observed. It is suggested that a new mechanism must be invoked to explain the data.