Optical Detection Of Paramagnetic Resonance In The Excited State Of F Centers In Cao

A detailed analysis of this double-resonance experiment shows that the emission takes place from the P3 excited level whose degeneracy is lifted by the Jahn-Teller coupling to Eg modes of vibration. An energy-level crossing effect is observed and its origin discussed. © 1972 The American Physical Society.28191268127

The Superconducting TESLA Cavities

The conceptional design of the proposed linear electron-positron collider TESLA is based on 9-cell 1.3 GHz superconducting niobium cavities with an accelerating gradient of Eacc >= 25 MV/m at a quality factor Q0 > 5E+9. The design goal for the cavities of the TESLA Test Facility (TTF) linac was set to the more moderate value of Eacc >= 15 MV/m. In a first series of 27 industrially produced TTF cavities the average gradient at Q0 = 5E+9 was measured to be 20.1 +- 6.2 MV/m, excluding a few cavities suffering from serious fabrication or material defects. In the second production of 24 TTF cavities additional quality control measures were introduced, in particular an eddy-current scan to eliminate niobium sheets with foreign material inclusions and stringent prescriptions for carrying out the electron-beam welds. The average gradient of these cavities at Q0 = 5E+9 amounts to 25.0 +- 3.2 MV/m with the exception of one cavity suffering from a weld defect. Hence only a moderate improvement in production and preparation techniques will be needed to meet the ambitious TESLA goal with an adequate safety margin. In this paper we present a detailed description of the design, fabrication and preparation of the TESLA Test Facility cavities and their associated components and report on cavity performance in test cryostats and with electron beam in the TTF linac. The ongoing R&D towards higher gradients is briefly addressed.Comment: 45 pages (Latex), 39 figures (Encapsulated Postscript), 53 Author

Effect of acid rain on outdoor insulators

This paper gives an overview of the acid rain problem in Europe, Poland and the Polish province of Silesia. The relationship between pH and water conductivity is shown. Different reactions between acid rain and particles are presented. Effects of temperature on the conductivity of H2SO4 solutions were studied. Finally, pollution flashover voltages and leakage currents on a model insulator that was contaminated with H2SO4 and other solutions were measured

Effect of a reclaimed municipal landfill on the quality of groundwater and surface water: A case study

Nieczynne, zrekultywowane, składowiska odpadów komunalnych mogą być negatywnym czynnikiem antropogenicznym wpływającym na środowisko naturalne. Wyniki przeprowadzonych w latach 1994-2003 badań hydrochemicznych w rejonie zrekultywowanego składowiska w Kurowicach koło Głogowa wskazują na niewielkie przenikanie zanieczyszczeń do wód podziemnych w północno-wschodniej części składowiska, przy czym strumień zanieczyszczonych wód obejmował jedynie otwór obserwacyjny zlokalizowany około 100 m na północ od składowiska. Nie stwierdzono kontaktu hydraulicznego silnie zanieczyszczonych wód podziemnych z wodami powierzchniowymi (Brzegnicka Struga i zbiornik w dawnej żwirowni). Nie stwierdzono też korelacji pomiędzy zawartością jonów metali ciężkich w wodach podziemnych a wysokością opadów atmosferycznych i deponowanego wraz z nimi ładunku tych substancji, chociaż wystąpiły okresowe podobieństwa w trendach.Reclaimed municipal landfills are classified as potential anthropogenic polluters impacting upon the natural environment. The reclaimed object in question, located in Kurowice near Glogów in the west of Poland, was subject to hydrochemical investigations from 1944 till 2003. They revealed penetration of pollutants into the groundwater (not very extensive though) in the N-E section of the landfill, the stream of polluted water extending only to the sight-hole situated approximately 100 m northwards. No hydraulic contact was found to occur between highly polluted groundwater and surface water (Brzegnicka Struga and water reservoir in the former gravel pit). There was no correlation between the content of heavy-metal ions in the groundwater and the height of atmospheric precipitation or the precipitation-related deposition of heavy metals, although there were periodical similarities of trends