[en] I suggest that a 'scientific reticence' is inhibiting the communication of a threat of a potentially large sea level rise. Delay is dangerous because of system inertias that could create a situation with future sea level changes out of our control. I argue for calling together a panel of scientific leaders to hear evidence and issue a prompt plain-written report on current understanding of the sea level change issue

[en] We describe an experimental setup for making precision measurements of relative β-decay rates of "2"2Na, "3"6Cl, "5"4Mn, "6"0Co, "9"0Sr, "1"3"3Ba, "1"3"7Cs, "1"5"2Eu, and "1"5"4Eu. The radioactive samples are mounted in two automated sample changers that sequentially position the samples with high spatial precision in front of sets of detectors. The set of detectors for one sample changer consists of four Geiger-Müller (GM) tubes and the other set of detectors consists of two NaI scintillators. The statistical uncertainty in the count rate is few times 0.01% per day for the GM detectors and about 0.01% per hour on the NaI detectors. The sample changers, detectors, and associated electronics are housed in a sealed chamber held at constant absolute pressure, humidity, and temperature to isolate the experiment from environmental variations. The apparatus is designed to accumulate statistics over many years in a regulated environment to test recent claims of small annual variations in the decay rates. We demonstrate that absent this environmental regulation, uncontrolled natural atmospheric pressure variations at our location would imprint an annual signal of 0.1% on the Geiger-Müller count rate. However, neither natural pressure variations nor plausible indoor room temperature variations cause a discernible influence on our NaI scintillator detector count rate

[en] The absolute photoionization cross section for the astrophysically important C⁺ ion has been measured for the first time thus allowing a test of the predicted cross section from the Opacity Project. The measurements are performed with a new ion-photon merged beam setup at the ASTRID storage ring utilizing an undulator beam line. In addition to the predicted 2s2p(³P)np ²D and ²S autoionizing resonances, the ²P states which are not included in the theoretical predictions also contribute significantly to the ionization yield below the 2s2p(³P) limit. The cross section is determined with a precision of 10% and lies 5-25% below the theoretical prediction at 24-37 eV

[en] Absolute measurements of the photoionization cross sections of the singly charged ions in the sequence Ca to Ni are presented, focussing on the 3p → 3d resonance region. Major differences are found in both spectral structure and cross section as the 3d shell is filled progressively. The behaviour of the total oscillator strength is studied as well as its relation to the collapse of the 3d orbital. The 3p⁵3d ¹P term is found to have an influence on the spectra even when further 3d electrons are added and this dependence combined with the effect of Hund's rule leads to a considerable simplification in the structure of the absorption spectra before the half-filled 3d shell, while from the half-filled 3d shell Hund's rule is the main simplifying effect

[en] The absolute cross section for photoionization of Cr⁺ has been measured using the merged-beam technique, focusing on the region of the 'giant' 3p → 3d resonance. These new absolute data differ considerably from previous experimental data, with the result that the agreement between experiment and existing calculations has improved substantially. The neutral and ionized Cr spectra, previously believed to be completely different, are shown here to be rather similar. The role of the 3d⁵(⁶S) state in determining the special position of Cr among the 3d elements is emphasized. The experimental data are available at http://www.phys.au.dk/amo/atomphys/atomphys.htm. (letter to the editor)

[en] The absolute cross section for photoionization of Mn⁺ has been measured using the merged-beam technique, focusing on the region of the 'giant' 3p → 3d resonance. The main discrepancy between theory and earlier experiments has been removed. However, more extensive relativistic calculations are required for a rigorous comparison with theory