2,442 research outputs found
Investigation of an electromagnetic calorimeter based on liquid krypton
No full textEffects determining the energy and spatial resolution of a calorimeter based on liquid krypton have been studied. With cathode strips of 10 mm a spatial resolution of 0.4 mm has been obtained in a cosmic rays test. The energy resolution of the calorimeter (0.4 ton of krypton) has been measured with positrons, achieving a rms of 5.7% at E = 130 MeV and 1.7% at E = 1200 MeV. The measurements are compared to Monte Carlo simulations
Liquid krypton calorimeter for KEDR detector and last prototype results
No full textThe liquid krypton calorimeter for the KEDR-VEPP-4M experiment is described. The experimental results with a prototype, obtained at the tagged photon beam of VEPP-4M in the photon energy region between 50 and 4500 MeV, are presented. The results on the energy resolution are in a good agreement with the Monte-Carlo expectations and are equal to 6% and 2% at 100 and 1000 MeV respectively. The spatial resolution is about 1-1.5 mm in a wide energy region and agrees with the expected spatial resolution
Space and energy resolutions in a liquid krypton e.m. calorimeter
No full textResults of the experimental measurement of space and energy resolutions of a liquid krypton (LKr) e.m. calorimeter are presented. A prototype has been exposed to a positron test-beam in the energy range 130-1300 MeV at the VEPP-3 storage ring
The reasons for conceptual contradictions in evaluating hydrological role of boreal forests
No full textThe paper attempts to resolve contradictions in the evaluation of the hydrological significance of the boreal forest. The article focuses on the study of the hydrological cycle mainly at the local level in connection with the specificity of vegetation and background of climate. It is stated that the ratio between evaporation and runoff in the warm season is mainly determined by the productivity of land, and less by the type of vegetation, whether forests or other types of land. This effect is due to the fact that the root systems of large trees act as «powerful submersible pumps», evaporating moisture including from the lower soil horizons. In the cold season, when precipitation falls as snow and is permanently preserved in the snow cover, the intensity and direction of the flow of water is not associated with the productivity of vegetation, and is mainly determined by the type of vegetation (forest, treeless space) and by environmental conditions. It is argued that the ambiguity of the impact of forests on the redistribution of precipitation between evaporation and runoff is due mainly features balance of the snow moisture, which is defined as the structure of the forest cover as well as the environment. Concepts of the geographically-determined hydrological role of forests are suggested. The results explain the contradictions in the hydrological role of forests (water consumption and water yield) and may be useful in the formation of land-use strategies in the regions where relationship problems of water resources and forest cover are relevant
Liquid krypton electromagnetic calorimeter
No full textA calorimeter using 30 tons of liquid krypton for the KEDR detector is being constructed. The main effects which determine the energy and space resolution have been studied. An energy resolution of 1.7% at 1.2 GeV was obtained with the prototype. A space resolution of 0.4 mm for relativistic particles has been reached with the prototype
Recent results on prototype aerogel threshold counters for particle identification in the region 0.5-4.3 GeV/c
No full textThe recent development of new processes has led to the fabrication of small density silica aerogel with high optical quality. The BaBar experiment, in order to achieve its physics program, requires a good pion/kaon identification capability up to 4.3 GeV/c able to work inside a 1.5 T magnetic field. An aerogel threshold counter using the combination of two refractive indices (1.055 and 1.007) can be used to complete the angular coverage of the particle identification system in the forward region. Different detector geometries read out by two photodetector types (fine mesh phototubes and hybryd photodiodes) have been considered and tested in a CERN beam test
Liquid krypton calorimeter for KEDR detector
No full textA description of the liquid krypton calorimeter for the KEDR detector and experimental results on energy and position resolution obtained with prototypes are presented
- …
