Complete photoionisation experiments

Experiments in atomic photoionisation are considered complete in the sense that both the amplitudes and phases of the corresponding transition matrix elements can be determined. Such experiments have recently made remarkable progress and provided a wealth of new information in this field. The researchers have employed a variety of complementary techniques such as polarised radiation and targets, spin-resolved detection of electrons and coincident detection of two electrons in cases of double photoionisation. This rapidly developing field is reviewed in a selection of show-case examples for each method. The results are compared with different calculations and critically analysed with respect to the validity of the theoretical models employed for these calculations