23 research outputs found
Development of ultra-low mass and high-rate capable RPC based on Diamond-Like Carbon electrodes for MEG II experiment
A new type of resistive plate chamber with thin-film electrodes based on
diamond-like carbon is under development for background identification in the
MEG II experiment. Installed in a low-momentum and high-intensity muon beam,
the detector is required to have extremely low mass and a high rate capability.
A single-layer prototype detector with 2 cm 2 cm size was constructed
and evaluated to have a high rate capability of 1 MHz/cm low-momentum
muons. For a higher rate capability and scalability of the detector size, the
electrodes to supply high voltage was segmented by implementing a conductive
pattern on diamond-like carbon. Using the new electrodes, a four-layer
prototype detector was constructed and evaluated to have a 46% detection
efficiency with only a single layer active at a rate of (10 kHz). The
result is promising to achieve the required detection efficiency of 90% at a
rate of 4 MHz/cm with all the layers active.Comment: 5 pages, 8 figures. Contribution to XVI Workshop on Resistive Plate
Chambers and Related Detectors (RPC2022), September 26-30 2022. Submitted to
Nuclear Instruments and Methods in Physics Research Section A: Accelerators,
Spectrometers, Detectors and Associated Equipmen
Prototype study of and tolerant Resistive Plate Chamber with Diamond-Like Carbon electrodes
A novel Resistive Plate Chamber (RPC) was designed with Diamond-Like Carbon
(DLC) electrodes and performance studies were carried out for 384 gap configuration with a prototype.
The use of thin films coated with DLC enables an ultra-low mass design of with up to a four-layer configuration. At the same time, 42% MIP
efficiency, and 180 ps timing resolution per layer were achieved in a
measurement performed under a non-MIP charged particle
beam. In addition, we propose a further improved design for a
-scale detector that can achieve 90% four-layer efficiency in
an even higher beam. In this paper, we describe the
detector design, present the results of performance measurements, and
characterize the rate capability of the DLC-based RPCs with a performance
projection for an improved design.Comment: 8 page
Development of High Precision Timing Counter Based on Plastic Scintillator with SiPM Readout
High-time-resolution counters based on plastic scintillator with silicon
photomultiplier (SiPM) readout have been developed for applications to high
energy physics experiments for which relatively large-sized counters are
required. We have studied counter sizes up to mm^3 with
series connection of multiple SiPMs to increase the sensitive area and thus
achieve better time resolution. A readout scheme with analog shaping and
digital waveform analysis is optimized to achieve the highest time resolution.
The timing performance is measured using electrons from a Sr-90 radioactive
source, comparing different scintillators, counter dimensions, and types of
near-ultraviolet sensitive SiPMs. As a result, a resolution of ps at 1 MeV energy deposition is obtained for counter size mm^3 with three SiPMs ( mm^2 each) at each end of the
scintillator. The time resolution improves with the number of photons detected
by the SiPMs. The SiPMs from Hamamatsu Photonics give the best time resolution
because of their high photon detection efficiency in the near-ultraviolet
region. Further improvement is possible by increasing the number of SiPMs
attached to the scintillator.Comment: 11 pages, 17 figures, accepted by IEEE Trans. Nucl. Sc
Sensitive germanium thermistors for cryogenic thermal detector of Tokyo dark matter search programme
Sensitive n-type and p-type germanium thermistors were fabricated by the melt
doping technique and by the neutron transmutation doping (NTD) technique,
respectively, aiming at a use for the cryogenic thermal detector, or bolometer
of Tokyo dark matter search programme. We report on the measurements of the
sensitivities of these thermistors. In particular, the p-type thermistors are
sensitive enough to scale up our existing prototype LiF bolometer and realize a
multiple array of the bolometers with the total absorber mass of about 1\,kg.Comment: 14 pages, revtex, with 4 postscript figures appended (uuencoded
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Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks
无线传感器网络,作为全球未来十大技术之一,集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术,可实时感知、采集、处理、传输网络分布区域内的各种信息数据,在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议,并针对大规模的无线传感器网络设计了一种树状路由协议,它根据节点地址信息来形成路由,从而简化了复杂繁冗的路由表查找和维护,节省了不必要的开销,提高了路由效率,实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR(AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位:工学硕士院系专业:信息科学与技术学院通信工程系_通信与信息系统学号:2332007115216
Exploring the structure of hadronic showers and the hadronic energy reconstruction with highly granular calorimeters
Electromagnetic and hadronic calorimeters with an unprecedented high-granularity are being developed by the CALICE collaboration based on a variety of active sensor elements and absorber materials. We present the detailed structures of hadronic showers measured by the CALICE calorimeter prototypes to characterise the different stages of hadronic cascades in the calorimeters as well as comparisons with GEANT4-based simulations using different hadronic physics models. The high granularity of the detectors is exploited in the reconstruction of hadronic energy, both in individual detectors and combined electromagnetic and hadronic systems, making use of software compensation and semi-digital energy reconstruction. The performance of the reconstruction techniques for different electromagnetic and hadronic calorimeters, with silicon, scintillator and gaseous active elements are discussed
Study on Granularity Optimization for ILD Hadron Calorimeter
The CALICE Analogue Hadron CALorimeter (AHCAL) at the International Linear Collider (ILC) is a high-granularity hadron calorimeter based on scintillator tiles readout by MPPCs. Toward the construction of ILC, the AHCAL granularity is being optimized. We have studied mixed configurations of the granularity by using larger scintillator tiles. We first measured the performance of 60 × 60 mm tile, which is larger than the standard 30 × 30 mm tile. The uniformity of the response in the tile was found to be quite good although the light yield is reduced by a factor of two compared to the standard 30 × 30 mm tile, which can be recovered with a larger-area MPPC. A prototype detection layer composed of 144 pieces of 60 × 60 mm tiles was constructed. The detection layer was added to the AHCAL large technological prototype composed of 38 detection layers with 30 × 30 mm tiles. The detection layer was successfully tested in test beam experiments at CERN SPS. The measured performance of the detection layer is presented as well as the study on the possible saturation using the test beam data