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Differences in postcollision interaction (PCI) effects on Kr L_{3}M_{4,5}M_{4,5} Auger electron spectra were observed, depending on whether the initial photoionization occurred slightly above the K threshold or slightly above the L_{3} threshold. For the former, KL fluorescence emission most likely happens and then Auger processes due to the L_{3} hole follow. The time delay due to fluorescence causes a reduced shift of the Auger peak and tailing toward lower energy, since the Auger overtaking of the photoelectron happens later in time and at a location farther away from the ionic core, compared to the case for the simple one-step L_{3}M_{4,5}M_{4,5} Auger decay after L-shell photoionization. Time-dependent theory for PCI in multistep processes agrees well with experiment, illustrating the effect as an internal clock for the time-sequence of the dynamical process.

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Electron beam ion traps (EBITs) are ideal tools for both production and study of highly charged ions (HCIs). In order to reduce their construction, maintenance, and operation costs, we have developed a novel, compact, room-temperature design, the Heidelberg Compact EBIT (HC-EBIT). Four already commissioned devices operate at the strongest fields (up to 0.86 T) reported for such EBITs using permanent magnets, run electron beam currents up to 80 mA, and energies up to 10 keV. They demonstrate HCI production, trapping, and extraction of pulsed Ar16+ bunches and continuous 100 pA ion beams of highly charged Xe up to charge state 29+, already with a 4 mA, 2 keV electron beam. Moreover, HC-EBITs offer large solid-angle ports and thus high photon count rates, e.g., in x-ray spectroscopy of dielectronic recombination in HCIs up to Fe24+, achieving an electron-energy resolving power of E/ΔE > 1500 at 5 keV. Besides traditional on-axis electron guns, we have also implemented a novel off-axis gun for laser, synchrotron, and free-electron laser applications, offering clear optical access along the trap axis. We report on its first operation at a synchrotron radiation facility demonstrating the resonant photoexcitation of highly charged oxygen.

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Angular distributions (ADs) of O+ fragments from C 1s photoexcited CO detected in coincidence with carbon KVV Auger electrons emitted in the horizontal direction were measured at photon energies of 298, 305, 320, and 450 eV. At 450 eV, the ADs are polarization-independent and coincide with the molecular-frame Auger electron angular distribution. All measured ADs can be rationalized as a product of the same molecular-frame Auger electron angular distribution and the axial selectivity in the photoionization process. Thus the interaction between the photoelectron and the Auger electron for the normal Auger decay of CO can be neglected, and the two-step model is a good approximation.

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A photochemistry study on nitrous oxide making use of site-selective excitation of terminal nitrogen, central nitrogen, and oxygen 1s-->3pi excitations is presented. The resonant Auger decay which takes place following excitation can lead to dissociation of the N2O+ ion. To elucidate the nuclear dynamics, energy-resolved Auger electrons were detected in coincidence with the ionic dissociation products, and a strong dependence of the fragmentation pathways on the core-hole site was observed in the binding energy region of the first satellite states. A description based on the molecular orbitals as well as the correlation between the thermodynamical thresholds of ion formation and the first electronic states of N2O+ has been used to qualitatively explain the observed fragmentation patterns.

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We have measured the vibrational structures of the N 1s photoelectron mainline and satellites of the gaseous N2 molecule with the resolution better than 75 meV. The gerade and ungerade symmetries of the core-ionized (mainline) states are resolved energetically, and symmetry-dependent angular distributions for the satellite emission allow us to resolve the Sigma and Pi symmetries of the shake-up (satellite) states. Symmetry-adapted cluster-expansion configuration-interaction calculations of the potential energy curves for the mainline and satellite states along with a Franck-Condon analysis well reproduce the observed vibrational excitation of the bands, illustrating that the theoretical calculations well predict the symmetry-dependent geometry relaxation effects. The energies of both mainline states and satellite states, as well as the splitting between the mainline gerade and ungerade states, are also well reproduced by the calculation: the splitting between the satellite gerade and ungerade states is calculated to be smaller than the experimental detection limit.

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Two recent theoretical studies [C. Liu, Phys. Rev. A 64, 010501 (2001)]; M. Zitnik, ibid. 65, 032520 (2002)]] predict that the fluorescence lifetimes of helium doubly excited states converging to He+ N=2 should be longer than that of the He+ 2p ion state. This effect is caused by the electric field of the outer electron which, through Stark mixing, gives the inner fluorescing electron some series specific, stabilizing 2s character. We have obtained the first experimental evidence that confirms this effect by measuring the lifetime of the 2p3d(1P0) doubly excited state. This was determined to be 190+/-30 ps compared to 100 ps for the He+ 2p ion state. The measurements were performed using short pulses of synchrotron radiation to form doubly excited states and recording the arrival time of photons from fluorescence.

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Temperature profiles within a mine waste rock dump undergoing pyritic oxidation have been used to estimate the rate of oxidation and the sites where oxidation was occurring. The waste rock dump is located at the abandoned Rum Jungle mine site in Northern Australia and was a major source of pollution to the local river system. The dump was rehabilitated in 1983-84 by reshaping to reduce erosion and covering with clay and soil to reduce infiltration of water.Heat source distributions were derived from temperature profiles measured in the dump. The oxidation of pyritic material is the main cause of heat in the dump, hence the rate and location of oxidation can be obtained from the distribution of heat sources. A comparison of the heat source distributions before and after rehabilitation showed that rehabilitation greatly reduced or stopped the oxidation of pyrite in the dump.

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The clinical features and management of 29 consecutive cases of liver abscess admitted to the Medical Division at the Rashid Hospital, Dubai, between February 1979 and March 1982 are reviewed and the value of CAT scan in the diagnosis and management is assessed.

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A case of pulmonary hydatid disease with myopathy, which has not previously been described as a feature of hydatidosis, is reported. The myopathy resolved during high dose mebendazole therapy.

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A case of tropical splenomegaly syndrome in a 66-year-old white man who had lived in Tanzania for 34 years is described. He had taken anti-malarial prophylaxis continuously and regularly. He had had malaria in 1955 but there was no history of alcoholism or jaundice. He was treated with proguanil hydrochloride and, after return to Tanzania, took paludrine as prophylactic. One year later he had no further complaints, the spleen was no longer palpable and the liver only just palpable.

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A hospital outbreak of haemorrhagic fever took place in Dubai in November, 1979. The index case died in the casualty department shortly after admission. There were five secondary cases among hospital staff, two of whom died. When, 3 months after this outbreak, a patient with symptoms characteristic of haemorrhagic fever was admitted, immediate barrier nursing prevented further secondary cases.

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