Multiphoton Ionization as Time-Dependent Tunneling

A new semiclassical approach to ionization by an oscillating field is presented. For a delta-function atom, an asymptotic analysis is performed with respect to a quantity h, defined as the ratio of photon energy to ponderomotive energy. This h appears formally equivalent to Planck's constant in a suitably transformed Schroedinger equation and allows semiclassical methods to be applicable. Systematically, a picture of tunneling wave packets in complex time is developped, which by interference account for the typical ponderomotive features of ionization curves. These analytical results are then compared to numerical simulations and are shown to be in good agreement.Comment: 36 pages (also printable half size), uuencoded compressed tarred Latex file with 9 Postscript figures included automaticall

Patients’ Perceptions of Risky Developments During Psychotherapy

Research on risks and unwanted effects is largely missing in psychotherapy. Using exploratory factor analysis six dimensions of personal therapy situation were identified in a preliminary study, three of them were associated with risky developments during the psychotherapeutic process: (1) (poor) quality of therapeutic relationship, (2) burden caused by psychotherapy, and (3) dependency/isolation. Based on the finding of this study an online survey was performed to examine these three dimensions. Aside from these three factors another variable was associated with risky therapy developments: the online questionnaire also asked for premature terminations of psychotherapy as a consequence of risky conditions for the therapeutic development. Risky conditions were found to be associated with the following variables: (1) the combination of female patient–male therapist, (2) the therapeutic orientation (particularly with the psychodynamic approaches) and (3) the duration of therapy. Fewer humanistic and systemic psychotherapies were found among the high risk-prone group of patients who were at risk in at least three of the four variables which were associated with risky developments. Differences in the findings of the study regarding the four therapeutic orientations stress the importance of an extensive differential indication and a cooperative partnership between patient and therapist, in order to facilitate a positive patient participation towards the choice of therapy method and subsequent successful participation throughout the course of treatment. Further studies should also focus on female patient and male therapist psychotherapies