Glass-coated beryllium mirrors for the LHCb RICH1 detector

The design, manufacture and testing of lightweight glass-coated beryllium spherical converging mirrors for the RICH1 detector of the LHCb experiment are described. The mirrors need to be lightweight to minimize the material budget and fluorocarbon-compatible to avoid degradation in the RICH1 C₄F₁₀ gas radiator. Results of the optical measurements for small-sized prototypes and for a full-sized prototype mirror are reported.     

Instruments and procedures for time calibration of the LHCb muon detector

We describe the dedicated circuits and the procedures implemented in the LHCb muon system aimed at an accurate time calibration of the detector channels. Time calibration is crucial for the correct operation of the hardware trigger level of the LHCb experiment.     

LHCb Vertex Locator prototyping,testing and production

LHCb is the experiment at the Large Hadron Collider (LHC) dedicated to the study of CP violation in the B-system. Its silicon vertex detector, named VELO for VErtex LOcator, will precisely reconstruct the primary pp interaction vertex, the displaced B-decay vertex and tracks originating from them. The use of the VELO in the LHCb trigger together with its operation in a harsh radiation environment puts additional constraints on the design. The project is soon entering the production phase. Recent results on the tests of prototype modules and components are presented with a focus on the sensor and front-end chip performance.     

The off-detector opto-electronics for the optical links of the ATLAS Semiconductor Tracker and Pixel detector

The off-detector part of the optical links for the ATLAS SCT and Pixel detectors is described. The VCSELs and p–i–n diodes used and the associated ASICs are described. A novel array packaging technique is explained and an analysis of the performance of the arrays and the overall system performance is given. The proposed procedure for the set-up of the optical links in ATLAS is described.     

Silicon beam telescope for CMS detector tests

A beam telescope providing precision track measurements as reference for other detectors has been upgraded in the CERN H2 test beam. The apparatus was completely rebuilt from the detector wafers and front-end electronics to the data acquisition system. The new detector setup consists of eight 5.6×5.6 cm² sized DC coupled silicon microstrip detectors. Typical position resolution values of about 7.5 μm were measured. Details of the setup are described and results from the recent beam tests are reported.     

Silicon detector nonlinearity and related effects

An explanation is put forth for the observed nonlinearity in the red spectral region of the response of silicon photodiodes. Experiments are described to support the explanation; and the results, implications, and precautions indicated for the use of these diodes are given. Correlation of nonlinearity with spatial nonuniformity of response is demonstrated.     

New concept of a submillimetric pixellated Silicon detector for intracerebral application

A new beta⁺ radiosensitive microprobe implantable in rodent brain dedicated to in vivo and autonomous measurements of local time activity curves of beta radiotracers in a volume of brain tissue of a few mm³ has been developed recently. This project expands the concept of the previously designed beta microprobe, which has been validated extensively in neurobiological experiments performed on anesthetized animals. Due to its limitations considering recordings on awake and freely moving animals, we have proposed to develop a wireless setup that can be worn by an animal without constraining its movements. To that aim, we have chosen a highly beta sensitive Silicon-based detector to devise a compact pixellated probe. Miniaturized wireless electronics is used to read-out and transfer the measurement data. Initial Monte-Carlo simulations showed that high resistive Silicon pixels are appropriate for this purpose, with their dimensions to be adapted to our specific signals. More precisely, we demonstrated that 200 μm thick pixels with an area of 200 μm×500 μm are optimized in terms of beta⁺sensitivity versus relative transparency to the gamma background. Based on this theoretical study, we now present the development of the novel sensor, including the system simulations with technology computer-assisted design (TCAD) to investigate specific configurations of guard rings and their potential to increase the electrical isolation and stabilization of the pixel, as well as the corresponding physical tests to validate the particular geometries of this new sensor.     

Silicon photodiode as a detector of exposure rate

The paper describes the utilization of a silicon photodiode as a detector of exposure dose rate. Theoretical considerations deal with the magnitude of the photocurrent as a function of minority carrier diffusion length and silicon thickness. Experimental results compare the sensitivity and radiation damage of photodiodes manufactured from various silicon materials. The photodiode energy dependence for photons in the range 7.6 keV to 1.25 MeV is also presented.     

Measurement system for evaluation of the muon chambers for the LHCb experiment

In a detector with the complexity of the LHCb, where only for the muon system more than 1300 chambers, divided into 20 different types, will be used, resulting on more than 120 k channels to be readout, it is of crucial importance to study the many types of chambers to create a complete knowledge of the detector operation and to guarantee a high-quality performance during the experiment. To make it possible, a complete setup was built and a C++ based software was developed to carry out a set of measurements on the full-equipped chambers of the LHCb muon detector. The setup is made of front-end control electronics, high-voltage supply and acquisition circuitry while the software, running on a PC, remotely controls each element of the system and implements a number of automatized procedures to assess the main characteristics of the chambers.The main advantages of this system are its versatility and speed of measurement which are crucial to the experiment since there is the need to characterize every single chamber before final installation. Moreover, in this work it was proposed to measure the starting knee of the high-voltage operational plateau without the use of an external trigger by making use of the internal structure of the chambers. Two laboratories were prepared at CERN (European Laboratory for Particle Physics) to receive this system; one used to test chambers arrived from the CERN itself and the PNPI (Petersburg Nuclear Physics Institute) production sites, and one to test the chambers arrived from the INFN (National Institute of Nuclear Physics) production sites. In this document, the hardware and software setup will be presented together with the measurement-oriented implementations.     

激光跟踪仪动态参数自动测试系统设计

介绍了中国计量科学研究院最新研制的激光跟踪仪动态参数自动测试系统.当前,对激光跟踪仪的评价普遍局限于静态参数的评定上,而该系统却通过测量激光跟踪仪在动态条件下的各性能指标,弥补了在动态指标评定方面的缺陷,从而可以从静态、动态两个方面对激光跟踪仪进行全面的评价.     

Design considerations and algorithms for partitioning optoelectronic multichip modules

There is considerable interest in the development of optical interconnects for multichip modules (MCM's) to improve their performance. For effective utilization of the optical and electronic technologies, a methodology for partitioning the system is required. The key question to be answered is which technology should be used for each interconnect in a given netlist: optical or electronic. We introduce the computer-aided design approach for partitioning optoelectronic systems into optoelectronic MCM's. We first discuss the design trade-off issues in an optoelectronic system design, including speed, power dissipation, area, and diffraction limits for free-space optics. We then define a formulation for optoelectronic MCM partitioning and describe new algorithms for optimizing this partitioning based on the minimization of the power dissipation. The models for the algorithms are discussed in detail, and an example of a multistage interconnect network is given. Different results, with the number and size of chips being variable, are presented in which improvement for the system packaging has been observed when the partitioning algorithms are applied.     

智能红外光探测器设计与实现

给出一种PIC单片机为核心的智能红外光束感烟探测器的设计。采用PIC16C711芯片嵌入探测器中作为控制芯片,完成对烟雾信号的探测采样和环境温度的检测,并利用模糊推理的滤波算法对检测数据进行分析处理,具有较好的环境适应性和可靠性。介绍了该探测器的硬件电路构成、系统软件设计及其实际应用情况。试验测试结果表明该智能红外探测器具有很好的探测烟雾的能力,作用距离50-100米。     

激光跟踪仪现场评定装置

介绍了一种用于激光跟踪仪现场快速评定装置,采用激光干涉仪作为标准器,能够生成任意标准长度,符合美国ASME B89.4.19的评价方法,同时还具有动态参数校准和角度标定功能,实现了激光跟踪仪在工业现场的快速评定.     

Design and test of a large-area scintillation detector for fast neutrons

A plastic scintillator array of 3.4 m² total area for the detection of neutrons in medium-energy nucleon–nucleon reactions was constructed and built. Calibration procedures for the detector were developed which allow the monitoring of gain shifts by means of muons from the cosmic radiation. Experiments were performed in order to calibrate the efficiency simulations and study the performance of the detector using the d+t→+n reaction at 14.7 MeV neutron energy and proton-induced deuteron breakup at 300 MeV.     

Design and rejection studies for a cylindrical transition radiation detector for the UA2 upgrade

A study of a compact and cylindrical transition radiation detector is described. A prototype has been built and tested with 40 GeV electrons and hadrons. The measurement have been done using 100 MHz FADC. We have compared different radiators and chamber geometries using various algorithms. The cluster counting and the total integrated charge methods give comparable results. A comparison between radiators of lithium and polypropylene is made.     

电子提花龙头检测器系统设计

国产电子提花龙头以其低廉的价格、优异的性能,赢得了广阔的市场。电子提花龙头检测器作为电子提花龙头质量检测手段,在生产电子提花龙头的过程中是必需的,能够提高电子提花龙头产品的质量、减少此产品的后续维护、降低电子提花龙头成本和提升产品的竞争力。设计了一种能够用于检测针数为1152/1344/2688电子提花龙头的检测器,并且应用于生产中,取得了良好的效果。     

Design of a high-resolution gamma-ray detector module for tomography applications

We present a modular gamma-ray detector design for gamma-ray tomography applications. As a key electronic component we use the APD array S8550 of Hamamatsu Corp. with 4×8 single APD elements each of 1.6 mm×1.6 mm size. For this APD array we tested and evaluated different configurations of 2 mm wide lutetium yttrium orthosilicate scintillation crystals. Emphasize was given to high counting efficiency and low dead time in order to secure applicability of the detector to tomography of objects with highly attenuating materials. For electronic processing, we designed a low-cost low-power charge-sensitive preamplifier circuit using commercially available operational amplifier ICs. The modular design of the detectors allows us to build up larger line or arc detectors.     

Design and performance of an electron-positron pair detector

An electron-positron pair spectrometer with nearly 4π acceptance is described. The spectrometer can detect e⁺e⁻ emission from nuclear 0 → 0 transitions and can be operated in coincidence with (backscattered) particles from a reaction exciting the pair-emitting state. The spectrometer has a cylindrical design with the target at the center. A cylinder of thin plastic scintillator divided into four segments identifies the electrons and positrons (ΔE) and is surrounded by a cylinder of thicker plastic scintillator also segmented into four quadrants to determine the total pair energy (E). The four ΔE scintillators are rotated 45° relative to the four thick E scintillators to increase the probability of identifying both members of the electron-positron pair. The efficiency of the spectrometer is determined at two different pair energies from measurements of the pair branches (100%) of the 0₂⁺ → 0₁⁺ transitions in ⁴⁰Ca and ¹⁶O. Pair detection efficiencies of (23.6±0.3)% and (36.3±0.7)% are obtained for the 3.35 MeV, ⁴⁰Ca and 6.05 MeV, ¹⁶O transitions, respectively.