Triply differential single ionization cross sections in coplanar and non-coplanar geometry for fast heavy ion-atom collisions

We have performed a kinematically complete experiment and calculations on single ionization in 100 MeV/amu C6+ + He collisions. For electrons ejected into the scattering plane (defined by the initial and final projectile momentum vectors) our first- and higher-order calculations are in good agreement with the data. In the plane perpendicular to the scattering plane and containing the initial projectile axis a strong forward-backward asymmetry is observed. In this plane both the first-order and the higher-order calculations do not provide good agreement neither with the data nor amongst each other.

An analytic geometry-variant approach to line ratio enhancement above the optically thin limit

We describe a simple theoretical model to investigate the anomalous effects of opacity on spectral line ratios, as previously studied in elements such as Fe XV and Fe XVII. The model developed is general: it is not specific to a particular atomic system, thus giving applicability to a number of coronal and chromospheric plasmas; furthermore, it may be applied to a variety of astrophysically relevant geometries. The analysis is underpinned by geometrical arguments, and we outline a technique for it to be used as a tool for the explicit diagnosis of plasma geometry in distant astrophysical objects.

Geometry- and diffraction-independent ionization probabilities in intense laser fields: Probing atomic ionization mechanisms with effective intensity matching

We report an experimental technique for the comparison of ionization processes in ultrafast laser pulses irrespective of pulse ellipticity. Multiple ionization of xenon by 50 fs 790 nm, linearly and circularly polarized laser pulses is observed over the intensity range 10 TW/cm(2) to 10 PW/cm(2) using effective intensity matching (EIM), which is coupled with intensity selective scanning (ISS) to recover the geometry-independent probability of ionization. Such measurements, made possible by quantifying diffraction effects in the laser focus, are compared directly to theoretical predictions of multiphoton, tunnel and field ionization, and a remarkable agreement demonstrated. EIM-ISS allows the straightforward quantification of the probability of recollision ionization in a linearly polarized laser pulse. Furthermore, the probability of ionization is discussed in terms of the Keldysh adiabaticity parameter gamma, and the influence of the precursor ionic states present in recollision ionization is observed.

The ABC for Life Programme - Teaching Basic Life Support in Schools

Background Less than 1% of the general public know how to assess or manage someone who has collapsed. It has been estimated that if 15–20% of the population were capable of performing cardiopulmonary resuscitation (CPR), mortality of out of hospital cardiac arrest could be decreased significantly. Training basic life support (BLS) skills to school children would be the most cost effective way of achieving this goal and ensuring that a large proportion of the population acquire basic life saving skills. Aims To assess retention of knowledge of basic life support 6 months after a single course of instruction in cardiopulmonary resuscitation designed specifically for school children. Setting School pupils in a rural location in one region of the United Kingdom. Methods A course of instruction in cardiopulmonary resuscitation – the ‘ABC for life’ programme – specifically designed to teach 10–12-year-old school children basic life support skills. The training session was given to school pupils in a rural location in Northern Ireland. A 22 point questionnaire was used to assess acquisition and retention of basic life support knowledge. Results Children instructed in cardiopulmonary resuscitation showed a highly significant increase in level of knowledge following the training session. While their level of knowledge decreased over a period of 6 months it remained significantly higher than that of a comparable group of children who had never been trained. Conclusion A training programme designed and taught as part of the school curriculum would have a significant impact on public health.