A pulsed crossed beam technique previously developed in this laboratory has been used to study the eledron impact ionization of copper. Previous measurements haw been very limited in scope and exhibit large discrepancies. Relative cross sections U" for the formation of I to 5 times ionized copper have been measured with high amuracy within the range 7.8-21OOeV. Individual cross sections have been obtained by normalization lo absolute values of uz obtained by Freund er a/ at energies below 200 eV using a fast crossed beam technique. Weak structures in a, can be attributed to Auger decay processes following the creation of 3s subshell and L shell vacancies but there is a lack of other pronounced structures in an for n > I where many close-lying subshell vacancies are involved. At 2100 eV cross sections us are less than three orders of magnitude smaller than U,,

Aims:To assess what proportion of all cardiac abnormality can be suspected at birth when all clinical examination before discharge is undertaken by a small stable team of clinicians. Methods: A prospective audit of all the 14 572 births in a maternity unit only staffed by nurse practitioners between 1996 and 2003. Results: 1.2% of all babies born in the unit were found to have a structural defect (as confirmed by echocardiography) within a year of birth. The number not suspected before discharge declined over time, and only 6% were first suspected after discharge in the last four years of this eight year study. Four potentially life threatening conditions initially went unsuspected in 1996-8, but none after that. A policy of referring every term baby with a murmur at 1 day of age that was still present at 7-10 days resulted in 4.2% requiring cardiac referral; 54% of these babies still had a murmur when assessed one to two weeks later, and 33% had a structural defect. Parents said in independent, retrospectively conducted, interviews that they found it confidence building to have any possible heart defect identified early and the cause of any murmur clearly and authoritatively explained. Conclusions: Effective screening requires experience and a clear, structured, referral pathway, but can work much better than most previous reports suggest. Whether staff bring a medical or nursing background to the task may well be of less importance.

A pulsed crossed-beam technique incorporating time-of-flight spectroscopy has been used to study the ionization of Ga by electrons at energies ranging from near threshold to 2100 eV. Relative cross sections for n-fold ionization where n = 1 to 4 have been normalized by reference to previous low-energy measurements of by Shul and co-workers based on a fast crossed-beam technique. Some large discrepancies have been noted between some of these and other previous measurements. Apart from some structure in the near-threshold behaviour of , the observed general lack of detailed structure in the multiple ionization cross sections is believed to be associated with the creation of many close-lying subshell vacancies. The measurements compare favourably with recent theoretical predictions based on semi-empirical scaling relations.

A crossed-beam technique, where the collision products have been selected by time-of-flight (TOF) spectroscopy with either a pulsed beam or coincidence counting, has been used to study pure ionization of Fe and Cu by 70-1440 keV amu-1 H+ and 35-425 keV amu-1 He2+ ions. Cross sections for the formation of q times ionized Fe and Cu products by pure ionization have been determined for q=1-4. A comparison with the corresponding (previously measured) cross sections for transfer ionization shows that, in the energy range considered, Fe+ and Cu+ ions arise predominantly through pure ionization. However, for q>or=2, contributions from both transfer ionization and pure ionization are important. Pure ionization becomes dominant at energies which increase as q increases. Measured cross sections for pure ionization have been successfully fitted to values based on an independent electron model approximation.

A crossed beam technique incorporating time-of-flight spectroscopy and coincidence counting of fast ion (atom)-slow ion collision products has been used to obtain for the first time separate cross sections for simple electron capture (charge transfer) and for transfer ionization in collisions involving Fe atoms. We have studied processes involving Fen+ formation in one-electron capture by 70-500 keV amu-1 H+ ions for n between 1 and 4 and both one and two electron capture by 37.5-360 keV amu-1 He2+ ions for n between 1 and 6. It is shown that, for the most part, total electron capture cross sections are dominated by contributions from transfer ionization processes rather than from simple charge transfer. The energy dependence of some of the measured cross sections exhibits interesting structure and the formation of the observed multicharged Fen+ ions is considered in terms of a model involving electron capture of either 4s, 3d or 3p target electrons together with electron removal through binary collisions at high velocities.