Dating of ice cores from Vernagtferner (Austria) with fission products and lead-210

Fission product (90Sr_ 90y, I37CS, total beta) and 2tOPb_210pO activities were measured in core samples from the temperate vernagtferner (3150 m altitude, Oetztal Alps, Austria). The results show that the investigated fission products are transported with water resulting from melting processes, and are sorbed on dust or dirt horizons. These products are, therefore, not suited for dating temperate glaciers. 210Pb is also transported with water and displaced from its original deposition. However, despite large fluctuations, the specific activity of 210Pb decreases with depth, and can be used to estimate accumulation rates and the age of the ice. The average annual accumulation rate amounts to about 80 cm water equivalent, and the deepest sample (81 m i. e. "" 65 m w. e.) was deposited in the beginning of this century. These results agree with data obtained from other observations on this glacier and show that the 210Pb_method is suitable to date temperate glaciers, if the ice cores cover a time interval of about 100 years (i. e. "" 4 half-lives of 210Pb). The surface activity of 210Pb was found to be 5 ± I dpm per kg of ice in agreement with other locations in the Alps and with measurements of fresh snow

The Impact of the Chernobyl Accident on a River/Groundwater Aquifer

The radionuclides 99mTc, 103Ru, 131I, 132Te, 134Cs and 137Cs, resulting from fallout from the damaged nuclear power plant at Chernobyl (USSR) were measured several times between May 2nd and 20th, 1986, in the River Glatt (Zürich, Switzerland) and in the adjacent shallow groundwater stream. Samples from the river and from different groundwater wells were filtered (0.45, 0.20, 0.05 Mm). The resulting water and the filters were assayed by 7-ray spectroscopy. For all these nuclides the main radioactivity ( > 75%) of the river water was found in the water passing the 0.05 Mm-filter. The fraction > 0.45 Mm contained the main particulate activity. Upon infiltration of river water into the groundwater stream iodine, ruthenium and tellurium are not, or only slightly sorbed, probably due to the formation of anionic or neutral species, whereas cesium is completely retained by the sediments. Particulate ( > 0.05 Mm) infiltration from the river into the groundwater is a negligible process

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Alignment of the CMS tracker with LHC and cosmic ray data

© CERN 2014 for the benefit of the CMS collaboration, published under the terms of the Creative Commons Attribution 3.0 License by IOP Publishing Ltd and Sissa Medialab srl. Any further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation and DOI.The central component of the CMS detector is the largest silicon tracker ever built. The precise alignment of this complex device is a formidable challenge, and only achievable with a significant extension of the technologies routinely used for tracking detectors in the past. This article describes the full-scale alignment procedure as it is used during LHC operations. Among the specific features of the method are the simultaneous determination of up to 200 000 alignment parameters with tracks, the measurement of individual sensor curvature parameters, the control of systematic misalignment effects, and the implementation of the whole procedure in a multi-processor environment for high execution speed. Overall, the achieved statistical accuracy on the module alignment is found to be significantly better than 10μm

The Impact of the Chernobyl Accident on a River/Groundwater Aquifer

The radionuclides 99mTc, 103Ru, 131I, 132Te, 134Cs and 137Cs, resulting from fallout from the damaged nuclear power plant at Chernobyl (USSR) were measured several times between May 2nd and 20th, 1986, in the River Glatt (Zürich, Switzerland) and in the adjacent shallow groundwater stream. Samples from the river and from different groundwater wells were filtered (0.45, 0.20, 0.05 Mm). The resulting water and the filters were assayed by 7-ray spectroscopy. For all these nuclides the main radioactivity ( > 75%) of the river water was found in the water passing the 0.05 Mm-filter. The fraction > 0.45 Mm contained the main particulate activity. Upon infiltration of river water into the groundwater stream iodine, ruthenium and tellurium are not, or only slightly sorbed, probably due to the formation of anionic or neutral species, whereas cesium is completely retained by the sediments. Particulate ( > 0.05 Mm) infiltration from the river into the groundwater is a negligible process