Development of crystal extraction studies at the IHEP accelerator
The crystal extraction of 10/sup 7/ proton/s at the BEC experimental facility is described. Detailed computer analysis is made to explain the basic experimental results. Future high-intensity efficient extraction using a short crystal is announced.
Crystal bending of the LHC beam for in situ calibration of ATLAS and CMS calorimeters
Abstract The physical possibility for bending the LHC protons and ions by a huge angle from 1° to 20° in the energy range of 0.45–7 TeV by means of a bent single crystal of silicon or germanium is studied. Such an application can be useful, e.g. for calibration of CMS or ATLAS calorimeters in situ by the LHC beam of precisely known energy. We show by simulations that this application would be feasible at the LHC, and report the experience of IHEP Protvino in bending 70 GeV protons by 9° (150 mrad) during 10 years of experiments in 1994–2004.
Frequency distributions of the mixing height over an urban area from SODAR data
The height of the mixing-layer (MLH) is an important parameter in the assessment of the dilution of primarily emitted or secondarily formed air pollutants in the atmospheric boundary-layer. A continuous measurement of MLH is possible only by remote sensing. Here, 17 months of SODAR data have been analysed automatically to derive the MLH over the city of Hannover in Northern Germany. In contrast to earlier studies the MLH has been determined from vertical profiles of the acoustic backscatter intensity and from the variance of the vertical velocity component. The results are presented in form of monthly frequency distributions and mean daily courses of MLH. These statistical evaluations of MLH show a clear annual course and interannual variability. The study shows the possibility to derive meaningful climatological information from long-term SODAR measurements for air quality issues.