TANGO Array.: 2. Simulations

The angular and energy resolutions of the TANGO Array were obtained using extensive Monte Carlo simulations performed with a double purpose: (1) to determine the appropriate parameters for the array fitting to the desired range of sensitivity (the knee energy region), and (2) to construct a reliable shower database required for reference in the analysis of experimental data. The AIRES code, with the SIBYLL hadronic collision package, was used to simulate Extended Air Showers produced by primary cosmic rays (assuming protons and iron nuclei), with energies ranging from 10¹⁴ to 10¹⁸ eV. These data were fed into a realistic code which simulates the response of the detectors (water Cherenkov detectors), including the electronics, pickup noise, and the signal attenuation in the connecting cables. The trigger stage was considered in the simulations in order to estimate the trigger efficiency of the array and to verify the accuracy of the reconstruction codes. This paper delineates the simulations performed to obtain the expected behavior of the array, and describes the simulated data. The results of these simulations suggest that we can expect an error in the energy of the primary cosmic-ray of ∼60% of the estimated value and that the error in the measurement of the direction of arrival can be estimated as ∼4°. The present simulations also indicate that unambiguous assignments of the primary energy cannot be obtained because of the uncertainty in the nature of the primary cosmic ray.     

虚拟仪器技术在1∶1摩擦试验平台中的应用

将虚拟仪器技术应用于现代测控系统，利用计算机的软、硬件资源代替传统测控仪器中大量的硬件，已经成为测控系统发展的一个重要方向。提出一种基于虚拟仪器技术的智能测控系统。该系统有效的运用于1：1摩擦试验平台，实现实时多通道数据采集、实时数据处理及显示、试验数据的后期分析处理、以及生成及打印试验报告等功能。     

The TRACER instrument: A balloon-borne cosmic-ray detector

We describe a large-area detector for measurements of the intensity of cosmic-ray nuclei in balloon-borne exposures. In order to observe individual nuclei at very high energies, the instrument employs transition radiation detectors (TRD) whose energy response extends well beyond 10⁴ GeV amu⁻¹. The TR measurement is performed with arrays of single-wire proportional tubes interleaved with plastic-fiber radiators. An additional energy determination comes from the specific ionization in gas and its relativistic rise which is also measured with proportional tubes. The tubes also determine the trajectory of each cosmic-ray nucleus with mm-resolution. In total, nearly 1600 tubes are used. The instrument is triggered by large-area plastic scintillators. The scintillators, together with acrylic Cherenkov counters, also determine the nuclear charge Z of each cosmic-ray particle, measure the energy in the GeV amu⁻¹ region, and discriminate against low-energy background. We describe the details of this detector system, and discuss its performance in three high-altitude balloon flights, including two long-duration flights in 2003 and 2006 at Antarctic and Arctic latitudes, respectively. Scientific results from these flights are summarized, and possible future developments are reviewed.     

CUORE: The Challenge of a 988 Bolometer Array

The design of CUORE (an array of 988 TeO₂ bolometers working at ～10?mK) was based on the information acquired with a 40.7?kg prototype, named Cuoricino, that allowed to obtain the present best limit on the half-life of 0νDBD of ¹³⁰Te. In addition to providing important information on the different sources of spurious counts that limit the sensitivity for rare event experiments, Cuoricino allowed to study in detail the underground operation of a large array of bolometers (detector stability, noise sources and their reduction, off-line amplitude correction, …). Moreover, additional CUORE R&D tests, carried out after Cuoricino, have already brought considerable improvements on the detector such as a lower acquisition threshold, with the consequent possibility to study additional physics such as Dark Matter, a standardization of the assembly and a special wiring to reduce the microphonic noise. The results thus obtained allow to assert that CUORE will be the largest mass cryogenic experiment put into operation, with an excellent sensitivity for the study of rare events thanks to an expected extremely low radioactive background level of 0.01 counts/keV/kg/yr in the 0νDBD region.     

The PTB microbeam: a versatile instrument for radiobiological research

The PTB microbeam is routinely used for the irradiation of living cells using protons (1-20 MeV) and alpha particles (1-28 MeV). The beam diameter is approximately 2 microm (fwhm), achieved by focussing, resulting in an excellent energy resolution and practically no scattered particles. Recently, an electrostatic beam scanner was added to the facility which allows targeting of each cell within 1 ms. This and other improvements led to an increase in the experimental speed of the system to a maximum of 50,000 cells per hour including all experimental steps. To improve the versatility of the facility further, a module for automatic quantification of immunocytochemical staining was implemented. This allows the analysis of protein activation, taking into account the positional information of the irradiation run.     

EURECA: European-Japanese Microcalorimeter Array

The EURECA project aims to demonstrate technological readiness of a micro-calorimeter array for application in future X-ray astronomy missions, like Constellation-X, EDGE, and XEUS. The prototype instrument consists of a 5×5 pixel array of TES-based micro-calorimeters read out by two SQUID-amplifier channels using frequency-domain-multiplexing (FDM) with digital base-band feedback. The detector array is cooled by a cryogen-free cryostat consisting of a pulse tube cooler and a two stage ADR. Initial tests of the system at the PTB beam line of the BESSY synchrotron showed stable performance and an X-ray energy resolution of 1.5 eV at 250 eV for read-out of one TES-pixel only. Next step is deployment of FDM to read-out the full array. Full performance demonstration is expected end 2008.      

808nm大功率半导体量子阱激光器锁相列阵

在材料研究和器件特性分析的基础上，采用分子束外延方法（ＭＢＥ），成功地研制出低阈值电流密度、高量子效率、折射率缓变分别限制异质结单量子阱结构（ＧＲＩＮ－ＳＣＨ－ＳＱＷ）大功率半导体激光器锁相列阵，最大线性输出功率为１．５Ｗ（室温，连续），激射波长８０８±４ｎｍ，光－电转换效率最高达６２％，器件寿命考核（２５℃，ＣＷ）超过１０００小时无明显退化。     

虚拟仪器驱动程序设计

在虚拟仪器系统中，仪器驱动程序是连接仪器与用户界面的桥梁，是系统设计的一个关键。本文结合自行开发的基于VXI总线的多通道数字输入／输出模块仪器驱动程序，讨论了符合VXI总线即插即用规范的仪器驱动程序的一般设计方法，该方法对于其他的虚拟仪器驱动程序的开发具有参考与推广价值。     

1基于以太网的拖曳式线列阵声纳数据传输系统设计

1引言 随着低噪声潜艇和隐身技术的发展,潜艇水下辐射噪声和目标强度进一步下降,声纳探测更加困难.水面舰艇用的主/被动拖线阵声纳,具有较大的空间增益,可以利用传播损失相对较小、目标反射本领较大的低频信号,已被证明是拖线阵声纳的重要发展方向.其中,基阵信号的远距离传输是拖曳式线列阵声纳的关键技术之一.数据传输技术应用于拖曳式线列阵多传感器信号的实时数字传输,与传统的拖曳式线列阵相比,最大的不同点就是传感器信号的远距离传输采用数字信号,而不是模拟信号,这样可以克服模拟信号传输衰减、干扰大等问题.早期限制数字拖曳式线列阵发展的主要因素是数字信号传输问题,然而随着数字技术的发展,尤其是超大规模集成电路技术、光纤技术的突飞猛进,设计小型化、高速率的新型拖曳式线列阵声纳数字传输系统成为可能.     

The equivalent elastic crack: 1. Load-Y equivalences

The use of crack growth resistance curves (R–a) to predict the behaviour of cracked specimens is a well established practice for ceramic and cementitious materials. When the cohesive crack model can be applied to these materials it is shown that the use of R–a curves is equivalent to setting up an elastic equivalence that greatly simplifies the computations. This equivalence has its drawbacks and limitations. This paper analyzes a class of equivalences—the load (P) versus another variable—between cracked cohesive materials and linear elastic ones, ascertaining its applicability to the interpretations of fracture data.     

The ACE-MAESTRO instrument on SCISAT: description, performance, and preliminary results

The Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO) instrument on the SCISAT satellite is a simple, compact spectrophotometer for the measurement of atmospheric extinction, ozone, nitrogen dioxide, and other trace gases in the stratosphere and upper troposphere as part of the Atmospheric Chemistry Experiment (ACE) mission. We provide an overview of the instrument from requirements to realization, including optical design, prelaunch and on-orbit performance, and a preliminary examination of retrievals of ozone and NO(2).     

SZ-1D型单相袖珍式多功能现场校验仪的设计

本文介绍了单相袖珍式多功能现场校验仪的设计原理、方法和注意事项。     

Solid-State Nanopore Array: Manufacturing and Applications

Nanopore brings extraordinary properties for a variety of potential applications in various industrial sectors. Since manufacturing of solid-state nanopore is first reported in 2001, solid-state nanopore has become a hot topic in the recent years. An increasing number of manufacturing methods have been reported, with continuously decreased sizes from hundreds of nanometers at the beginning to ≈1 nm until recently. To enable more robust, sensitive, and reliable devices required by the industry, researchers have started to explore the possible methods to manufacture nanopore array which presents unprecedented challenges on the fabrication efficiency, accuracy and repeatability, applicable materials, and cost. As a result, the exploration of fabrication of nanopore array is still in the fledging period with various bottlenecks. In this article, a wide range of methods of manufacturing nanopores are summarized along with their achievable morphologies, sizes, inner structures for characterizing the main features, based on which the manufacturing of nanopore array is further addressed. To give a more specific idea on the potential applications of nanopore array, some representative practices are introduced such as DNA/RNA sequencing, energy conversion and storage, water desalination, nanosensors, nanoreactors, and dialysis.     

The Keck Array: A Multi Camera CMB Polarimeter at the South Pole

The Keck array is a new multi-camera Cosmic Microwave Background (CMB) polarimeter. Each camera contains 256 polarization pairs of antenna-coupled transition edge sensor (TES) bolometers. We recently deployed three of five cameras at the geographic South Pole, and plan to deploy the final two cameras in early 2012. This new telescope is an ideal instrument to search for the primordial B-mode polarization signal imprinted in the CMB by inflationary gravitational waves. We will discuss the design of the detectors and receivers, the status of current observations, and report on progress toward upgrading the instrument with the full compliment of polarized receivers.