Gefäß, Tasse

Rand- und Körperfragment einer Tasse. Konkaves Oberteilprofil, scharfe Knickwand und niedriger Unterteil. Schwarze Farbe. Außen: An Schulter umlaufenden Rillen. Am Körper bis zum Knick Stempeldekor mit senkrechten Winkeln und einem Punkt innen

Excitation functions for the production of long-lived residue nuclides in the reaction natBi(p;xn,yp)Z

Experimental and theoretical studies were performed to complete the data sets on the production of residue nuclides in natural Bi irradiated with protons. For the long-lived and difficult to measure isotopes108mAg,10Be,26Al as well as129I and36Cl, chemical systems had been developed aimed to isolate them from the bismuth matrix. The separation methods are based on distillation, precipitation and ion exchange. From the content of the radionuclides determined by accelerator mass spectrometry and γ-spectrometry, the production cross sections in the proton energy range from 100 to 2600 MeV were calculated. The experimental results were compared with theoretical predictions. Significant deviations between experiment and theory over the whole energy range were observed with increasing discrepancies for the production of the lighter residue nuclides

36Cl studies at the ETH/SIN-AMS facility

36Cl has been measured in polar ice from Dye 3 (65° 11 N, 43° 50 W) and Camp Century (77° 11 N, 82° 08W) in Greenland. In an exploratory study 4 series consisting of about 20 samples each have been selected covering approximately the following time periods: 12000-10000 BP (transition Wisconsin-Holocene), 1530–1730 a.d. (Maunder minimum), 1942–1977 a.d. (nuclear bomb pulse) and 1978 (seasonal variations). The results are compared with 10Be data of the same cores which were measured previously. The variations of the ratio 10Be36Cl are generally larger than expected from the experimental errors indicating that this ratio is not suitable for dating of old ice