Impact Analysis of the Atmosphere Optical State on Wind Lidar Sounding Range

One of the most important questions for correlation lidars is the sounding range question.Correlation lidar sounding range greatly depends not only on the parameters of the equipment, but also on the optical state of the earth's atmosphere.In addition, there are currently two approaches to the estimation of lidar sounding range. In one approach, an estimate of the sounding range is obtained by equating the detector threshold power to the laser signal power recorded by the detector. In another approach, an estimate of the sounding range is obtained by equating the minimum detectable energy of the detected laser signal energy.This paper is about impact research of the atmosphere optical state on wind correlation lidar sounding range and compare sounding range estimates obtained under the two different approaches to the energy calculation lidar.The analysis is carried out for the surface layer of the atmosphere, the horizontal sounding path and the radiation wavelength of 0.532 μm. In atmospheric haze conditions, an empirical formula is used for the attenuation factor. The signal-to-noise ratio is assumed to be 100.Solid-state Nd:YAG Ekspla lasers NL319 (lamp pumping, pulse energy 5 J) and NL231-100 (diode pumping, pulse energy 90 mJ) were chosen as radiation sources.Hamamatsu photomultiplier tube R5070A with radiant sensitivity ~ 50 mA/W was chosen as a detector.It is shown that in a wide optical state range (meteorological range of visibility from 20 to 2 km) the lamp-pumped laser source sounding range with pulse energy 5 J varies from ~ 3,8 km to ~ 1,2 km and the diode-pumped laser source sounding range with pulse energy 90 mJ varies from ~ 1,1 km to ~ 0,64 km.The approach based on comparison of the detector threshold power with the received laser signal power overestimates the sounding range due to incomplete influencing consideration factors.

The Super C-τ Factory particle identification system options

The Super C-τ (SCT) Factory at Novosibirsk is a project of new colliding beam experiment proposed in Budker Institute of Nuclear Physics. Electron-positron collider based on Crab-Waist technique for operation energy range 2–5 GeV in center of mass is suggested. The luminosity up to 1035cm−1s−1 (in 100 times higher than in operated today experiments in this energy region) is expected. To perform broad experimental program of the project successfully the excellent particle identification (PID) system is needed. A number of options are under consideration. Three of them are described in the paper: Focusing Aerogel RICH (FARICH) detector, threshold Cherenkov counters based on ASHIPH (Aerogel SHifter PHotomultiplier) technique with 6000 litres of aerogel of two refractive indexes and time-of-flight counters with TOP (Time of Propagation) approach with time resolution better than 30 ps. Comparison of PID capabilities with help of parametric simulation is given.

MEMS Based Dew Point Hygrometer With Optimal Self Adjusted Detection Threshold

A new system of dew point temperature hygrometer, based on semiconductor MEMS detector is presented in the paper. Many details of MEMS detector construction are given with details in the report. Basic idea of algorithms of detector control is also discussed. More attention is devoted to subalgorithm for self-adjusted detector threshold operation. Excellent dynamic parameters of the new hygrometer (i.e. 2÷5 dew point detections and temperature measurements per second), proved by the hygrometer tests, will be presented and described in the report. It means that presented hygrometer is 10÷100 times faster than conventional hygrometers. In the end of the paper two medical applications are demonstrated with clinical test results. The first application is for dermatology for TransEpidermal Water Loss (TEWL) factor of human skin. The second is focused on measurement of humidity in human nose cavity and human throat during breathing. In both case fast humidity measurements, with time constant of some 0.5s, have been required.