A new controlling system for the solar tower telescope of IZMIRAN: I. Guide

A new guiding system for the solar tower telescope is described. Two mutually perpendicular CCD arrays are used as photodetectors. The guide provides a positional error of no larger than 0.2″ in a frequency band of 0–10 Hz. The software allows for referring the spectrograph slit position to solar coordinate systems and provides for various guide operation modes.     

A new controlling system for the solar tower telescope of IZMIRAN: II. A solar image motion compensator

A solar image motion compensator for the solar tower telescope is described. Two mutually perpendicular CCD linear arrays are used as photodetectors. An algorithm for forecasting the system behavior is used for generation of correction signals. Analyzing the solar image motion data obtained using the compensator and without it has shown that, thanks to its use, the total image motion value decreases to 0.5″–0.6″ in a frequency band of 0–100 Hz, being close to the amplitude of noncorrelated image motion component. The compensator operates equally effectively in both the pointing and scanning modes.     

Note: improved sensitivity of photoreflectance measurements with a combination of dual detection and electronic compensation

A setup is described for performing photoreflectance (PR) measurements using two photodetectors, wherein the photodetectors need not be identical. The second detector monitors the photoluminescence and scattered pump laser background signal in real time. It is then eliminated from the measured PR signal using electronic circuits that compensate for amplitude and phase differences between the background signals from the two detectors. The technique overcomes the adverse effect of short-term fluctuations in the pump laser intensity. The signal-to-noise ratio is shown to improve significantly, enabling measurement of weak PR signals.     

Measurement of the Differential Ray Velocity and Longitudinal Magnetic Field on the Sun with CCD Photodetectors: Part I. Modulationless Method

A method for measuring the differential ray velocity and magnetic field strength on the sun in the modulationless mode with the use of a diffraction-grating spectrograph and CCD-based photodetectors is described. The optical arrangement of the device implementing this method is presented, and its operating principles are considered. The basic formulas for signal calculation are presented. The main advantages of this technique are the reduces effect of distorting atmospheric instabilities and suppression of the intrinsic noise of the grating spectrograph.     

Manufacturing-oriented developments of silicon multiplexers for multielement IR photodetectors

The architecture of silicon multiplexers for multielement IR photodetectors is considered. A review is given of industrially oriented developments of linear (1 × 32, 1 × 288, 1 × 576) and matrix (32 × 32, 128 × 128, 160 × 128, 320 × 256) silicon multiplexers for mid- and far-IR photodetectors based on cadmium-mercury-tellurium, lead-tin-tellurium, and multilayer structures with quantum wells. An analysis is made of the temperature resolution of matrix IR photodetectors based on multiplexers with row and frame integration of photo signals using micrometer to deep submicron CMOS technologies. Typical parameters of the multiplexer and some of the infrared photodetectors designed at the Rzhanov Institute of Semiconductor Physics, SB RAS are given.     

A mechanical light chopper based on a hard disk drive for systems of laser sounding of the atmosphere

An easily manufactured high-speed mechanical chopper based on a Maxtor D740X-6L hard disk drive with a rotation speed of 7200 rpm is described. It is shown experimentally and theoretically that the switching time of a light beam with a diameter of 0.8 mm is ∼20 μs. The described chopper can be used in systems of laser sounding of the atmosphere for protection of photodetectors against a high-power backscattered signal from a near zone of the sounding line, as well as in other problems where fast mechanical switching of a light beam is required.     

On-line testing of flip-chip assemblies

This paper considers a destructive method of testing the strength flip-chip assemblies (in particular, photodetectors) which consists of separating one microcircuit from another with heating (not below 383 K) after thermal cycling. The method can be used to test the adhesive properties of bonding bumps, for example indium ones, in flip-chip assemblies and determine the causes of debonding in photodetectors. Examples of the causes of failures of cooled photodetectors based on HgCdTe molecular beam epitaxy are discussed.     

硅光电探测器的发展与应用

半导体光电探测器由于体积小、灵敏度商、响应速度快、易于集成,是最理想的光电探测器,典型的包括PIN光电二极管、雪崩二极管以及硅光电倍增管.论述了它们的工作原理,以及在光纤通信、传感系统、高能物理、核医学等领域的广泛应用.     

A study of avalanche photodetectors with a large photosensitive surface in the photon counting mode

The possibility of operating author-designed avalanche photodetectors with a large photosensitive surface (7-mm² area) in the photon counting mode at room temperatures is shown. The characteristics of these photodetectors and ΦД-115Л avalanche photodiodes are compared in the photon counting mode.     

柔性薄膜太阳能电池用不锈钢基板的成形技术

综述了不锈钢基底薄膜太阳能电池的研究进展及其不锈钢基板的国内外生产情况,并针对柔性薄膜太阳能电池对不锈钢基板的品质要求,介绍了不锈钢基板的成形过程,其中包括基板的轧制成形、光亮退火及拉伸矫直等一系列关键技术。     

FY-3A太阳辐射监测仪的程控设计与实现

介绍了载于FY-3A气象卫星用来监测太阳辐照度变化的太阳辐射监测仪(SIM)的工作原理,描述了该监测仪的系统组成和工作模式。SIM由3台相同的太阳辐照绝对辐射计(SIAR)按一定角度排列构成测量三通道,3个通道可单独或同时进行测量,对获得的数据进行对比、查验和校正。分别介绍了太阳辐射监测仪的3种工作模式,即通道自测模式、太阳辐射测量模式和冷空间测量模式,在此基础上对其执行的在轨运行任务进行了分析说明。讨论了程控设计要点与实现,给出了SIM采用各测量模式获得的遥感数据。FY-3A太阳辐射监测仪从2008年6月开始执行在轨测量,得到的实验结果表明,设计的测量模式合理,运控参数有效,全部软件功能均已实现,测量得到的太阳辐照度与同国际同期卫星SORCE/TIM的测量数据在0.2%以内相符。     

Computer automation of data acquisition from a Knudsen, torsion-effusion pendulum

A computer-automated data acquistion system has been developed for a dynamic torsion pendulum applied to measurement of vapor pressures at high temperatures by the torsion-effusion method. Laser beams reflected from mirrors on the pendulum are detected by a bank of photodetectors which, in turn, transmit signals representing pendulum positions through an encoder and interface to a laboratory computer with an internal clock. The computer uses pendulum position and time data with stored information to solve the equation of motion of the pendulum and to calculate vapor pressures. The physical parts, electronic circuits, and software are described and discussed. The rest point of a dynamic torsion pendulum has been reproduced within 1 min of arc.     

Structural optimization of a Cu(In,Ga)Se2 thin film solar cell using numerical simulation and design of experiment techniques

The structural optimization for a thin film solar cell module based on Cu(In,Ga)Se₂ is investigated through numerical simulation and sequential statistical analyses. First, an equivalent numerical model for solar cells is constructed with an electrical circuit consisting of large area diodes and analysis using finite element analysis (FEA). A good agreement in performance characteristic curves between the developed numerical model and practical solar cells is obtained after performing parameter adjustments. To maximize the light conversion efficiency, an optimization technique using the design of experiment (DOE) of orthogonal arrays is employed. The programmed block diagram is used to calculate electric potentials inside solar cell layers and the associated solar performances. Statistical analysis of variance (ANOVA) and F-test are used to discover the dominant design variables (DVs) which are more important on solar cell performances. The second order regression model which relates dominant DVs with solar cell efficiency is mathematically obtained by the employment of response surface model (RSM) and graphically described by the equipotential contour plots.     

Three-spectrum multielement photodetector device

The design and characteristics of a three-spectrum multielement photodetector device with a sensitivity range from 0.6 to 12.0 μm, which consists of three arrays of photodetectors having sensitivity ranges 0.6–0.9, 3–5, and 8–12 μm, are described. Methods of fabrication of photodetector arrays, the photodetector device as a whole, and its photoelectric characteristics are presented.     

A fast reciprocal space method for image simulation

In this paper, we introduce a fast reciprocal space method for image simulation. It is well known that the scattering matrix (SM) P with NxN elements consists of N different structure factors and N different excitation errors. However, most structure factors of the SM P are extremely small so that they can be neglected. Therefore, the size of the SM P is reduced drastically. On the other hand, the structure factors have two-dimensional space group symmetries, so that by reducing the symmetry related structure factors to symmetrically independent structure factors, the size of the SM P can be reduced further. The calculation speed based on the simplified SM P will be several hundred times faster than that by other conventional methods. In this paper, we describe the method for how to reduce the SM P in detail and give an example of implementation.     

Structural diversity of sphingomyelin microdomains

In cells plasma membrane, sphingomyelin (SM) plays a key role in the formation of a category of lipid microdomains enriched in cholesterol (Chl) often referred to as rafts. Atomic force microscopy (AFM) was used to analyze the mesoscopic topography of enriched SM microdomains in supported bilayers made of SM/dioleoylphosphatidylcholine (SM/DOPC) and SM/palmitoyl-oleoyl-phosphatidylcholine (SM/POPC) equimolar mixtures, in buffer, at room temperature. Gel–fluid phase separation occurs in both SM/DOPC and SM/POPC bilayers. The gel phase SM-enriched microdomains adopt a variety of size, shape and mesoscopic structure, from homogeneous flat domains of a few hundreds of nanometer in diameter to domains of several micrometers made of closely packed globular structures. Gel–gel phase separation in SM domains is also observed which gives rise to different structures for the diunsaturated and the mixed-saturated PC species. These differences could also extend to the interactions with Chl. This suggests that studies on rafts formation commonly performed using SM/DOPC mixture as a model should also include the physiologically more relevant POPC species.     

紫外光电探测器高精度线性测量装置

基于双光阑法，研制了一种紫外光电探测器高精度线性测量装置，主要由高稳定钨带灯、带有快门的双光阑屏、石英透镜、紫外光栅双单色仪和计算机组成，测量波长范围为200-400nm.给出了该装置的原理、测量方法及数据处理方法。测量过程由计算机配套专用软件进行自动控制。利用该线性测量装置，对光电倍增管探测器进行了线性测量。实验结果表明：该装置测量精度高、速度快，测量不确定度小于O．05％，可应用于对精度要求高的紫外光电探测器线性度的测量。     

A proposed design for a polarization-insensitive optical interferometer system with subnanometric capability

A bidirectional, fringe-counting, two-beam interferometer system is described that can be used for precision length measurement with any laser source that is adequately coherent for the application. The two electrical phase-quadrature signals required for bidirectional electronic counting are obtained from photodetectors at the two interferometer outputs. A thin metal film design for the beam-splitter coating introduces the required phase difference of nearly 90° for both the perpendicular and parallel polarization components. Electronic alignment and control are performed by a system used to continuously monitor the signals produced from the outputs and automatically process these signals to achieve the optimum performance from the interferometer. Interferometers using the technique require a limited amount of optical alignment and all of the electronic adjustments are automatically controlled by the electronic system. These instruments are economical to manufacture and easy to apply in practice, readily achieving subnanometric accuracy in the measurement of changes in optical path.     

Radiation detectors based on gas electron multipliers (Review)

Remarkable features of gas electron multipliers (GEMs) make them attractive for numerous applications in high-energy physics, nuclear physics, astrophysics, and the medical-imaging field. This review presents the results of research and development of GEM-based radiation detectors. The operating principles of GEMs and their main characteristics, including the physics of multistage GEMs and their operation in pure noble gases, are expounded. GEM-based detectors of ionizing radiations are considered. In particular, the data on tracking detectors are briefly described, while more detailed data, including the data on two-phase avalanche detectors, are presented for detectors operated at high pressures and cryogenic temperatures. A special Section is devoted to the development of GEM-based gas photodetectors.     

太阳能水下自主航行器发电系统设计

首先介绍了太阳能水下航行器光伏系统的一般结构,然后对太阳能电池阵列的设计和太阳能充电器部分做了重点研究.提出了太阳能电池阵列的设计和太阳能充电器的设计,并研究了基于变步长扰动观察法的太阳能最大功率跟踪(MPPT),描述了蓄电池的充电控制策略,给出了具体的软件实现方法.