ABSOLUTE EXPERIMENTAL AND THEORETICAL TDCS FOR KR(4P) ELECTRON IMPACT IONIZATION S. J. Cavanagh#, Birgit Lohmann#, J. Rasch=86, C. T. Whelan=87 and H. R. J. Walters* #School of Science, Griffith University, Nathan Queensland 4111 AUSTRALIA =86Institut de Physique, Laboratoire de Physique Mol=E9culaire et des= Collisions,=20 Technop=F4le, Metz 200, Rue Arago, FRANCE =87Dept. of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 9EW, UK *Dept. of Applied Mathematics and Theoretical Physics, The Queen's University, Belfast BT7 1NN, UK The triple differential cross section for electron impact ionization has been measured for Kr(4p) ionization and compared with a distorted wave Born approximation calculation. The experimental data have been placed on an absolute scale using a technique which uses a theoretical cross section for He(1s) ionization as a reference.=20