Construction Of Chamber Research Articles

Construction and test of the SM1 MicroMegas chambers for the upgrade of the forward muon spectrometer of the ATLAS experiment

Abstract MICRO MEsh GASeous structure chambers, MicroMegas (MM (Giomataris et al., 1996 [1] )), is an innovative design concept for Micro-Pattern Gaseous Detectors, designed in order to provide a high spatial resolution and to cope with highly irradiated environments. These chambers have been chosen as new precision tracking detectors for the upgrade of the forward muon spectrometer of the ATLAS experiment during Long Shutdown 2 (LS2, 2019–2020). MM trapezoidal detector modules, with areas of 2–3 m 2 , will be part of the two New Small Wheels (NSW (ATLAS collaboration, 2013 [2] )) composing the innermost station of the ATLAS muon tracking system. ATLAS MM detectors are composed out of 4 read-out (RO) layers, two for the reconstruction of the precision coordinate and two with stereo reading ( ± 1 . 5 °) for the reconstruction of the second coordinate. MM chambers are designed to provide a resolution better that 100 μ m on the precision coordinate with an efficiency of at least 95% per single plane for a rate capability up to 15 kHz/cm 2 , in presence of magnetic fields up to 0.3 T. The Istituto Nazionale di Fisica Nucleare (INFN) is deeply involved in the construction of these chambers and their validation at the Cosmic Ray Stand (CRS) in the Frascati INFN site (LNF). Preliminary results on the tests performed on the INFN SM1 prototypes are presented. Copyright 2018 CERN for the benefit of the ATLAS Collaboration. CC-BY-4.0 license.

Physical implementation of immersive boundary conditions in acoustic waveguides

The physical implementation of so-called immersive boundary conditions (IBCs) allows the construction of anechoic chambers, where wavefield reflections from the boundary of a physical domain, such as a wave propagation laboratory, are actively suppressed by emitting a secondary wavefield at the domain boundary that destructively interferes with the reflected waves. Moreover, IBCs enable immersive wave propagation experimentation by linking the wave propagation in the physical domain with the propagation in a numerical domain enclosing the physical domain. In this case, IBCs correctly account for all wavefield interactions between both domains, including higher-order scattering. The physical implementation of IBCs is achieved by densely populating the boundary surrounding the physical domain with transducers that enforce the necessary boundary conditions. The signals required at the injection boundary are predicted with the help of a secondary surface of transducers that record the wavefield on a surface slightly inside the physical domain. The recorded wavefield is extrapolated to the boundary by evaluating a Kirchhoff-Helmholtz integral in real-time using an FPGA-enabled data acquisition, computation and control system. Here, we present results of the active suppression of broadband boundary reflections in 1D and 2D acoustic waveguides.

Possibilities of improvement fuel atomization process in CI – engines

Modern combustion engines development is targeted on respect of environment protection. Engine constructor main task is lowering toxic substances emission in exhaust. This trend is the same for CI and spark ignition engines. Toxic substances content in exhaust depend on many factors like combustion chamber construction, the sort of fuel and inlet system, fuel – air mixture organize process, the sort of fuel and engine work environment. It was very important period in motorization development implementing electronic engine work steering systems. The factors influence on emission in exhaust analysis shows that there is possibility reduce toxic substances in fumes through correct organizing fuel – air combustion mixture in CI – engine. The injecting fuel streams parameters influence on combustion mixture forming process. The article presents fuel injector modification concept. The aim of modern fuel injector modification is improvement of fuel stream parameters like range, width, atomization and obtuse angle. The performing researches show that making changes on non – working needle part influence especially on particles and carbon monoxide emission.

Legislature by Lot: Envisioning Sortition within a Bicameral System

In this article, we review the intrinsic democratic flaws in electoral representation, lay out a set of principles that should guide the construction of a sortition chamber, and argue for the virtue of a bicameral system that combines sortition and elections. We show how sortition could prove inclusive, give citizens greater control of the political agenda, and make their participation more deliberative and influential. We consider various design challenges, such as the sampling method, legislative training, and deliberative procedures. We explain why pairing sortition with an elected chamber could enhance its virtues while dampening its potential vices. In our conclusion, we identify ideal settings for experimenting with sortition.

Acoustic Method Based on Integrity Coefficient for Testing the Loose Circle of Surrounding Rock

The thickness of the loose circle of surrounding rock is an important index in tunnel support parameter design and rock mass stability evaluation. Accurate and rapid determination of thickness is critical to ensure the safety of underground chamber construction. Field test is the most intuitive and accurate method for thickness determination. Acoustic method is also widely used because of its high precision, low cost, and simple operation. However, existing discriminative standards for analysis of test results are ambiguous and subjective; as such, a uniform standard that defines a loose circle has not been established yet. In this study, the complete degree of rock and loose rock mass is quantitatively analyzed by introducing the concept of and the calculation formula for the integrity coefficient of broken rock (Rv) and the integrity coefficient of loose circle (Lv). According to the formation principle of loose circle, the criteria and test method for surrounding rock loose circle are proposed on the basis of the integrity coefficient. The integrity coefficient of the loose circle (Rv) is assumed to be approximately equal to that of the broken rock (Lv) in chamber excavation. In the test of the surrounding rock loose circle in the Shimen tunnel at Baohan highway, the integrity coefficient (Rv) of the rock of the grade Ⅲ gneiss was 0.53 according to the combined indoor and field tests. The thickness of the type Ⅲ surrounding rock loose circle was 0.55-1.35 m, and the distribution along the circumference was not uniform. The arch shoulder was thick, and the wall was thin, consistent with the initial stress state of the surrounding rock. Comparison with the results of the original acoustic wave loosening test showed that the new discriminant method based on the integrity coefficient is more accurate and reliable. The proposed method could be used for the design and construction of tunnels.

Construction of Multi Wire Proportional Chambers for the CBM Transition Radiation Detector

The Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) will explore the QCD phase diagram in the region of high net-baryon densities. The Transition Radiation Detector (TRD) with its multi-layer design will provide electron identification for higher momenta and contribute to the fragment identification.

DESENVOLVIMENTO DE UMA CÂMARA DE BAIXO CUSTO PARA ENVELHECIMENTO ACELERADO DE POLÍMEROS

O objetivo deste trabalho é descrever o projeto, construção e testes de uma câmara de baixo custo para envelhecimento acelerado de polímeros, que atenda um ciclo de baixa e outro de alta radiação ultravioleta sobre os corpos de prova, de acordo com a norma ASTM G154. A metodologia baseou-se no levantamento das normas relacionadas aos ensaios de envelhecimento acelerado de polímeros e dos equipamentos já existentes, fornecendo os subsídios para o desenvolvimento do projeto, que foi validado pela construção e avaliação de seu desempenho. O controle da câmara é realizado por um sistema eletrônico baseado em Arduino e utiliza componentes disponíveis no mercado, que atendam as especificações do projeto. O equipamento atendeu aos requisitos previstos, tanto em relação às especificações, quanto ao baixo custo e integrará os laboratórios da Universidade de Mogi das Cruzes (UMC), campus Villa-Lobos, para realização de ensaios de materiais poliméricos.

Design and Analysis of Experimental Setup for Hydrogen PPM Measurement

Vacuum Chambers are used to achieve Ultra High Vacuum Pressures (10-7 to 10-16 Torr.) for the processes like Plasma Generation, X-ray Photoelectron Spectroscopy, Surface analysis etc. The reason behind the application of UHV pressures in above fields is to enable readily clean and contamination free surfaces during the experiment. These vacuum chambers are constructed by materials like Aluminum, Glass, Brass, Inconel, Monel Metal and Stainless Steels. Among all, Austenitic Stainless Steel (ASST 304 L) are the most reliable choice for high and ultra-high vacuum Systems because they are cost effective, corrosion resistant, effectively outgassed, good machinability and weldability. Therefore, vacuum chambers of ASST 304 L for use in lower 10-9-10-10 Pa region are often pretreated by baking in order to decrease the hydrogen outgassing, which is the main residual gas in that pressure range. The material for the construction of ultra-high vacuum chambers has to process at different time for different temperatures. Baking in ambient air is easy and cost effective. Therefore, design and analyze of the experimental setup to investigate the hydrogen ppm in different sample, can be carried out for different bake out.

Automation with renewable energy to optimize the exploitation of water supply networks in Ninh Thuan province

The research that was conducted on the water supply network of Phan Rang city, Ninh Thuan province, is aimed at using renewable energy to optimize the management and reduce the water loss. The research has conducted DMA (District Metering Area) setup, construction and installation of flow meter and pressure reducing valve chamber for flow and pressure control with active pressure regulation, and the use of hydraulic power generator to generate power at the site. Research results provide management agencies, in particular, water supply companies, with optimal solutions in network management and energy saving, reducing the amount of water loss effectively, thereby increasing revenue and saving clean water - precious resources are gradually depleted.

Корейский полуостров и Японские острова: сложение особенностей и заимствование культурных традиций в эпоху палеометалла (материалы к учебному курсу «Археология зарубежной Азии»)

Purpose. The period of the most intensive contacts of the ancient population of the Korean peninsula and the Japanese Islands (3rd – 7th centuries AD) is of special interest for study. The period witnessed a wide spread of the tradition of building burial mounds (kurgans). Due to the artifacts found in the kurgans, it becomes possible to study various aspects of the people’s social life, including cultural contacts. We aimed at studying territorial alliances based on the cultural and historical background, such as the spread of agriculture based on wet rice cultivation, bronze and iron production, the emergence of states. Results. The kurgan tradition on the Korean peninsula is associated with the era of the Three Kingdoms (3rd – 7th centuries AD). The tradition of erecting mounds started in Koguryo state in the 1st century BC, then from the 3rd century AD it continued in Baekje, Silla and Kaya, and disappeared in the middle of the 6th century AD because of adopting Buddhism. Common barrows had stone embankments, but they are also found with earthen mounds. Burial chambers were first constructed vertically, then horizontal ones appeared. On the Japanese Islands, kurgans first appeared during the Yayoi period (3rd century BC – 3rd century AD) and were widely constructed during the Kofun period (3rd – 7th centuries AD). The barrows had earthen embankments with burial chambers inside. The barrows differed in the form of their embankment and size. The burials of the Kofun period in Japan continued the Yayoi period traditions to a certain extent. They had earthen embankments and were decorated with bronze mirrors and stone ornaments in the burial chambers. In addition, their feature is clay haniva figurines around the perimeter of the embankment. Starting from approximately the 5th century AD, there began to appear a certain homogeneity in the funerary structures of the Korean peninsula and the Japanese archipelago. Sueci ceramics became a typical element of the funeral rite, as well as bronze and iron objects, gold jewelry and luxury items which appeared in burial chambers. The construction of kurgans acquired some new features, such as stone chambers with side corridors. Both on the Korean Peninsula and the Japanese Islands, we observe similar types of embankments, such as round (embun), square (ho:fun), double round (so:embun), double square (so:ho:fun) and in the form of a “Japanese sea scallop” (hatategaishikikofun). Conclusion. The study of the structural features of the kurgans on the Korean Peninsula and the Japanese Islands allows us to conclude that there are similarities in the forms and materials of embankments and the forms of burial chamber construction. The main difference is the larger size of Japanese kurgans. The similarities we revealed can be explained by the mutual influence of the population of the Korean peninsula and the Japanese islands.

New Submersed Chamber for Calibration of Relative Humidity Instruments at HMI/FSB-LPM

This paper gives a detailed description of a new chamber designed for calibration of relative humidity (RH) instruments at Laboratory for Process Measurement (HMI/FSB-LPM). To the present time, the calibrations of RH instruments at the HMI/FSB-LPM were done by comparison method using a climatic chamber of large volume and calibrated dew point hygrometer with an additional thermometer. Since 2010, HMI/FSB-LPM in cooperation with Centre for Metrology and Accreditation in Finland (MIKES) developed the two primary dew point generators which cover the dew point temperature range between \(-\,70~{^{\circ }}\hbox {C}\) and \(60~{^{\circ }}\hbox {C}\). In order to utilize these facilities for calibrations of the RH instruments, the new chamber was designed, manufactured and installed in the existing system, aiming to extend its range and reduce the related calibration uncertainties. The chamber construction allows its use in a thermostatic bath of larger volume as well as in the climatic chambers. In the scope of this paper, performances of the new chamber were tested while it was submersed in a thermostated bath. The chamber can simultaneously accommodate up to three RH sensors. In order to keep the design of the chamber simple, only cylindrical RH sensors detachable from display units can be calibrated. Possible optimizations are also discussed, and improvements in the design proposed. By using the new chamber, HMI/FSB-LPM reduced the expanded calibration uncertainties (level of confidence 95 %, coverage factor \(k=2\)) from 0.6 %rh to 0.25 %rh at 30 %rh \((23~{^{\circ }}\hbox {C})\), and from 0.8 %rh to 0.53 %rh at 70 %rh \((23~{^{\circ }}\hbox {C})\).

Touchscreen technology in the study of cognition-related behavior.

There is a growing need for new translational animal models designed to capture complex behavioral phenotypes implicated in addiction and other neuropsychiatric conditions. For example, a complete understanding of the effects of commonly abused drugs, as well as candidate medications, requires assessments of their effects on learning, memory, attention, and other cognition-related behavior. Modern touch-sensitive technology provides an extremely flexible means to expose an experimental subject to a variety of complex behavioral tasks designed to assay dimensions of cognitive function before, during, and after drug administration. In addition to tailored variants of gold-standard cognitive assessments, touchscreen chambers offer the ability to develop novel tasks based upon the researcher's needs. This methods perspective presents (i) a brief review of previous touchscreen-based animal studies, (ii) a primer on the construction of a touch-sensitive experimental chamber, and (iii) data from a proof-of-concept study examining cross-species continuity in performance across a diverse assortment of animal subjects (rats, marmosets, squirrel monkeys, and rhesus macaques) using the repeated acquisition task - a modern variant of a traditional animal model of learning. Taken together, the procedures and data discussed in this review illustrate the point that contemporary touchscreen methodology can be tailored to desired experimental goals and adapted to provide formal similarity in cognition-related tasks across experimental species. Moreover, touchscreen methodology allows for the development of new translational models that emerge through laboratory and clinical discovery to capture important dimensions of complex behavior and cognitive function.

Examination of a chamber of a large fusion facility by means of neutron activation techique with nanosecond neutron pulse generated by dense plasma focus device PF-6

Analysis of neutron fields around large chambers of main-stream nuclear fusion facilities is an important problem. The neutron emission from Dense Plasma Focus (DPF) device is anisotropic itself. It may be additionally distorted by an architecture details of the hall and construction elements of a facility hosting the particular DPF setup. The compact plasma focus device PF-6 is a quasi-point source producing nanosecond pulse of about 108 2.5-MeV neutrons with narrow energy spectrum. It was used for examination of a chamber of the large plasma installation PF-1000. The construction of the PF-1000 chamber simulates neutron scattering and absorption taking place in a main-stream fusion facility. The silver-based activation monitors were used for a survey of the neutron emission field in all directions. Such a device can be further used for inertial confinement fusion (ICF) and tokamak chambers examination and for calibration of its neutron diagnostics.

Small-sized reverberation chamber for the measurement of sound absorption

This paper presents the design, construction, calibration and automation of a reverberation chamber for small samples. A balance has been sought between reducing sample size, to reduce the manufacturing costs of materials, and finding the appropriate volume of the chamber, to obtain reliable values at high and mid frequencies. The small-sized reverberation chamber, that was built, has a volume of 1.12 m3 and allows for the testing of samples of 0.3 m2. By using diffusers, to improve the diffusion degree, and automating measurements, we were able to improve the reliability of the results, thus reducing test errors. Several comparison studies of the measurements of the small-sized reverberation chamber and the standardised reverberation chamber are shown, and a good degree of adjustment can be seen between them, within the range of valid frequencies. This paper presents a small laboratory for comparing samples and making decisions before the manufacturing of larger sizes.

Optimization of Construction of the Mixing Chamber with a Multiple Jets Inlet of a Heat Carrier in Pneumatic Conveying Dryers for Potassium Chloride

Results are presented for physical and mathematical modeling of the operation of different mixing chambers with a multiple jets inlet of a heat carrier in pneumatic conveying driers for potassium chloride. The influence of the shape of the chamber and the spacing of holes for heat carrier input on temperature inhomogeneity of the resulting mixture, particulates temperature and contact intensity of particulates with the chamber walls are considered. A mixing chamber design providing minimal contact intensity and sticking of the dryable particulates with the walls is recommended.

Design, construction and performance tests of a prototype micromegas chamber with two readout planes in a common gas volume

In this paper, the design and the performance of a prototype detector based on MicroMegas technology with two detection planes in a common gas volume is discussed. The detector is suited for the forward region of LHC detectors, addressing the high-rate environment and limited available space. Each detection plane has an active area of 9×9cm2 with a two-dimensional strip readout and is separated by a common gas region with a height of 14mm. A micro-mesh, working as a cathode, is placed in the middle of the common gas volume separating it into two individual cells. This setup allows for an angle reconstruction of incoming particles with a precision of ∼2mrad. Since this design reduces the impact of multiple scattering effects by the reduced material budget, possible applications for low energy beam experiments can be envisioned. The performance of the prototype detector has been tested with a 4.4GeV electron beam, provided by the test beam facility at DESY.

Physical implementation of immersive boundary conditions in one dimension

Immersive boundary conditions (IBCs) are a novel approach to target-oriented numerical wavefield modeling. When implemented physically, IBCs allow the construction of anechoic chambers that actively suppress the reflection of wavefields from the boundaries of a physical domain, such as a wave propagation laboratory. Moreover, IBCs can be used for immersive wave propagation experimentation by linking the wave propagation in the physical domain with the propagation in a virtual domain enclosing the physical domain. In this case, the IBCs correctly account for all wavefield interactions between the two domains. The physical implementation of IBCs is achieved by densely populating the boundary surrounding the physical domain with transducers that enforce the necessary boundary conditions. To estimate the signals that need to be emitted at the injection boundary, a second surface of transducers slightly inside the physical domain records the propagating wavefield. The recorded wavefield is extrapolated to the injection boundary by evaluating a Kirchhoff-Helmholtz integral in real-time using an FPGA-enabled data acquisition and control system. A recently constructed one-dimensional acoustic wave propagation laboratory provides an ideal setup for the physical installation of IBCs in one dimension. In this work, we demonstrate the implementation of IBCs on one side of this laboratory.

PV-0419: The impact that geometric variability in ionization chamber construction has on kQQo

PV-0419: The impact that geometric variability in ionization chamber construction has on kQQo

Design and construction of low-cost respiration chambers for ruminal methane measurements in ruminants

ABSTRACTRuminant animals contribute significantly to methane emissions in tropical regions. Nonetheless, there are few facilities available in those regions of the world for in vivo measurement of methane production in cattle. The aim of the present work was to describe the design, construction and operation of respiration chambers for in vivo measurement of methane production in cattle in Mexico. Locally available materials were used in the construction. Walls, roof and doors were constructed of thermic panels with two windows of acrylic at the front so the animal can be observed at all times. Chambers have an air volume of 9.97 m3. Air is drawn from the chamber at a rate of 500 L/min by the effect of mass action flow generators. Methane was measured in air samples with an infrared analyzer. Chambers operate under a slight negative pressure of around -500 Pa. Air temperature inside the chambers is kept at 23 °C with an air conditioner, while relative humidity is maintained at 55 % with a dehumidifier. Functioning of the chambers was evaluated in Bos indicus, Nelore cattle fed Taiwan grass (Pennisetum purpureum) and a concentrate (18 % crude protein), and measurements were made during runs of 23 h duration. Methane production was on average 173.2 L per day, while the emission factor was 17.48 L methane per kilogram o dry matter consumed. It concludes that this respiration facility is capable of measuring methane production accurately in cattle fed tropical rations.

Design of metallic parabolic anechoic chamber for compact range measurement

Anechoic chambers are used for indoor antenna measurements. The common method for anechoic chamber construction is to cover all inside walls by the EM absorbers. A fully metallic parabolic chamber is presented in which the propagation of the EM waves inside the chamber is controlled and they are guided to an absorber. In the proposed method, an appropriate quiet zone with plane wave illumination is obtained, and unlike ordinary anechoic chambers the absorber usage is decreased greatly. The performance of the chamber is evaluated by simulation and the results showed that the proposed method could provide a useful technique for the compact range antenna measurements.