Cross sections for the formation of slow molecular and energetic fragment ions in the photoionization of hydrogen and deuterium have been determined using synchrotron radiation within the energy range 25–40 eV. Superexcited states have been shown to play an important role in the photoionization process but recently predicted resonance effects have not been observed.

In The Gambia, metal-roof houses were hotter during the day than thatched-roof houses. After 24 h, the mortality of Anopheles gambiae , the principal African malaria vector, was 38% higher in metal-roof houses than thatched ones. During the day, mosquitoes in metal-roof houses moved from the hot roof to cooler places near the floor, where the temperature was still high, reaching 35 °C. In laboratory studies, at 35 °C few mosquitoes survived 10 days, the minimum period required for malaria parasite development. Analysis of epidemiological data showed there was less malaria and lower vector survival rates in Gambian villages with a higher proportion of metal roofs. Our findings are consistent with the hypothesis that the indoor climate of metal-roof houses, with higher temperatures and lower humidity, reduces survivorship of indoor-resting mosquitoes and may have contributed to the observed reduction in malaria burden in parts of sub-Saharan Africa.

Broadband extreme ultraviolet molybdenum/yttrium aperiodic multilayer analyzers were designed for polarization experiments in 8.5-11.7 nm wavelength range. The multilayer analyzers were made using direct current magnetron sputtering and characterized using the soft x-ray polarimeter at BESSY-II facility. Measured s reflectivities at the Brewster angle are 5.5% for a multilayer designed for 8.5-10.1 nm wavelength range and 6.1% for one designed for 9.1-11.7 nm. The multilayers also exhibit high polarization degree up to 98.79%. In addition, the multilayer was also measured over 38°-52°angular range at the fixed wavelength of 10.2 nm and the mean s reflectivity is 6.2%.

Experimental results on aperiodic broadband transmission molybdenum/silicon multilayer phase retarders for the extreme ultraviolet range are presented. The broadband phase retarders were designed using a numerical method and made using direct current magnetron sputtering on silicon nitride membrane. The polarization properties of these aperiodic transmission phase retarders have been investigated using the soft x-ray polarimeter at BESSY-II. The measured phase shift was about 42° in the wavelength range of 13.8–15.5nm, and the corresponding s-component transmission (Ts) decreased from 6% to 2% with increasing wavelength.

Long-lived, excited neutral particles, arising from the interaction of monochromatic synchrotron radiation with ground state He atoms, have been observed at photon energies close to the (N = 1,2,3 and 4) ionization thresholds. The measurements have been made using an unconventional experimental arrangement in which charged particles, responsible for the dominant signal in conventional photon impact studies, are prevented from reaching the detector. For , it appears that the formation, via photoexcitation, of relatively long-lived, doubly excited Rydberg states is a necessary step in the production of the observed signal. Four processes that might account for the production of the excited neutral particles are considered. The simplest, that atoms in the initial doubly excited Rydberg states are themselves directly observable, is considered unlikely. However, the lifetimes of the photoexcited double Rydberg states may be increased through the effects of electric fields present in the apparatus. Transitions from these double Rydberg states, occurring either as a result of collisions or by fluorescence, could result in metastable, singly excited neutral particles. The presence of signal related to the existence of long-lived doubly excited states could be significant in the interpretation of other photon impact measurements.