Development of Gas Electron Multiplier(GEM) for digital radiographic system

International Nuclear Information System (INIS)

Moon, B. S.; Chung, C. E.; Lee, J. W.

2000-04-01

Two computer programs SHOWFIELD and IMAGEQUAL have been developed. SHOWFIELD is used to draw electric field lines for GEM detectors and IMAGEQUAL is used to study the spatial resolution of x-ray images. Various simulation runs have been carried out using EGS4 to study the characteristics of electrons generated by micro-channel plates and Ar, Xe gases. A prototype GEM detector was developed through this project. The GEM detector is composed of a pair of GEM plates, a micro-channel plate, readout circuit in a gas filled chamber. GEM plate were made in CERN to meet KAERI's design specification and the micro-channel plates were purchased from Proxitronic company

Overview of the GEM muon system cosmic ray test program at the SSCL

International Nuclear Information System (INIS)

Milner, E.C.

1993-04-01

Muon track resolution exceeding 75-μm per plane is one of the main strengths of the GEM detector design, and will be crucial in searches for Higgs Bosons, heavy Z-Bosons, technicolor, and supersymmetry. Achieving this resolution coal requires improved precision in muon chambers and their alignment. A cosmic ray test stand known as the Texas Test Rio, (TTR) has been created at the SSCL for studying candidate GEM muon chamber technologies. Test results led to selecting Cathode Strip Chambers (CSC) as the GEM muon system baseline chamber technology

Conceptual design and development of GEM based detecting system for tomographic tungsten focused transport monitoring

Science.gov (United States)

Chernyshova, M.; Czarski, T.; Malinowski, K.; Kowalska-Strzęciwilk, E.; Poźniak, K.; Kasprowicz, G.; Zabołotny, W.; Wojeński, A.; Kolasiński, P.; Mazon, D.; Malard, P.

2015-10-01

Implementing tungsten as a plasma facing material in ITER and future fusion reactors will require effective monitoring of not just its level in the plasma but also its distribution. That can be successfully achieved using detectors based on Gas Electron Multiplier (GEM) technology. This work presents the conceptual design of the detecting unit for poloidal tomography to be tested at the WEST project tokamak. The current stage of the development is discussed covering aspects which include detector's spatial dimensions, gas mixtures, window materials and arrangements inside and outside the tokamak ports, details of detector's structure itself and details of the detecting module electronics. It is expected that the detecting unit under development, when implemented, will add to the safe operation of tokamak bringing the creation of sustainable nuclear fusion reactors a step closer. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

Characteristics of triple GEM detector for the ALICE TPC upgrade at CERN

International Nuclear Information System (INIS)

Patra, Rajendra Nath; Singaraju, R.N.; Ahammed, Z.; Nayak, T.K.; Viyogi, Y.P.; Biswas, S.

2016-01-01

Gas Electron Multiplier (GEM) detector, introduced by F. Sauliin 1997 and has been widely improved in last two decades for applications to high energy physics experiments and imaging. GEM detectors have several advantages, like good spatial resolution (∼100 μm), high detection efficiency (>98%), high rate handling capability (∼105 Hz/mm"2 ) and reasonable time response (∼5 ns). The unique features of the GEM detector make it suitable for experiments at Large Hadron Collider (LHC) at CERN and FAIR at GSI. With the increase of beam luminosity of LHC for its next phase of running from the year 2020, the ALICE experiment is planning to take data for PbPb collisions at a rate of 50 kHz. The ALICE Time Projection Chamber (TPC) will be upgraded by GEM based read-out to fulfil this future goal. In this report, results of a thorough test in the laboratory using a newly developed online data monitoring system are discussed

GEM Building Taxonomy (Version 2.0)

Science.gov (United States)

Brzev, S.; Scawthorn, C.; Charleson, A.W.; Allen, L.; Greene, M.; Jaiswal, Kishor; Silva, V.

2013-01-01

This report documents the development and applications of the Building Taxonomy for the Global Earthquake Model (GEM). The purpose of the GEM Building Taxonomy is to describe and classify buildings in a uniform manner as a key step towards assessing their seismic risk, Criteria for development of the GEM Building Taxonomy were that the Taxonomy be relevant to seismic performance of different construction types; be comprehensive yet simple; be collapsible; adhere to principles that are familiar to the range of users; and ultimately be extensible to non-buildings and other hazards. The taxonomy was developed in conjunction with other GEM researchers and builds on the knowledge base from other taxonomies, including the EERI and IAEE World Housing Encyclopedia, PAGER-STR, and HAZUS. The taxonomy is organized as a series of expandable tables, which contain information pertaining to various building attributes. Each attribute describes a specific characteristic of an individual building or a class of buildings that could potentially affect their seismic performance. The following 13 attributes have been included in the GEM Building Taxonomy Version 2.0 (v2.0): 1.) direction, 2.)material of the lateral load-resisting system, 3.) lateral load-resisting system, 4.) height, 5.) date of construction of retrofit, 6.) occupancy, 7.) building position within a block, 8.) shape of the building plan, 9.) structural irregularity, 10.) exterior walls, 11.) roof, 12.) floor, 13.) foundation system. The report illustrates the pratical use of the GEM Building Taxonomy by discussing example case studies, in which the building-specific characteristics are mapped directly using GEM taxonomic attributes and the corresponding taxonomic string is constructed for that building, with "/" slash marks separating attributes. For example, for the building shown to the right, the GEM Taxonomy string is: DX1/MUR+CLBRS+MOCL2/LWAL3/

A New Era of Air Quality Monitoring from Space in East Asia: Korea's Geostationary Environmental Monitoring Spectrometer (GEMS) and an Integrated Korea-US Air Quality (KORUS-AQ) Study

Science.gov (United States)

Hong, J.; Hong, Y.; Song, C. K.; Kim, S. K.; Chang, L. S.; Lim, J.; Ahn, J.; Park, J. H.; Kim, J. Y.; Han, Y. J.; Kim, J.; Park, R.; Lee, G.; Lefer, B. L.; Al-Saadi, J. A.; Crawford, J. H.

2015-12-01

Due to remarkable economic growth over the last two decades, East Asia has become a region experiencing some of the poorest air quality in the world. In addition to local sources of pollution, the Korea peninsula is downwind of the largest emission sources in East Asia, complicating the understanding of air quality over Korea. Thus, knowing the factors controlling changes in air pollution across urban-rural and marine-continental interfaces, in addition to the contributions from local emissions and transboundary transport, is important for building effective management strategies and improving air quality in East Asia. GEMS (Geostationary Environmental Monitoring Spectrometer) is a satellite instrument planned for launch in 2019 by the Republic of Korea. The instrument will observe East Asia and the western Pacific region, providing real-time monitoring of air quality (e.g. O3, NO2, SO2, HCHO, AOD, etc.) and enabling better scientific understanding of the transboundary transport of air pollutants. The KORUS-AQ (the Korea and U.S. Air Quality) field campaign will take place in May - June 2016 and will employ an integrated observing strategy including multiplatform observations (i.e. ground stations, aircraft, ships, and satellites) and chemical transport models. This mission aims to not only strengthen our knowledge of atmospheric chemistry but also provide important data sets for validating GEMS retrieval algorithms. In preparation for KORUS-AQ, a pre-campaign has been successfully conducted in Korea during early summer 2015 with observations from multiple ground sites and a small aircraft. A brief summary of pre-field campaign results will be presented. Moving forward, the GEMS mission and KORUS-AQ study will lead to a new era of air quality monitoring in East Asia. GEMS will also make critical contributions to the global air quality perspective working in concert with geostationary missions launched by the U.S. (TEMPO: Tropospheric Emissions: Monitoring of

Glycemic load, exercise, and monitoring blood glucose (GEM): A paradigm shift in the treatment of type 2 diabetes mellitus.

Science.gov (United States)

Cox, Daniel J; Taylor, Ann G; Singh, Harsimran; Moncrief, Matthew; Diamond, Anne; Yancy, William S; Hegde, Shefali; McCall, Anthony L

2016-01-01

This preliminary RCT investigated whether an integrated lifestyle modification program that focuses on reducing postprandial blood glucose through replacing high with low glycemic load foods and increasing routine physical activities guided by systematic self-monitoring of blood glucose (GEM) could improve metabolic control of adults with type 2 diabetes mellitus, without compromising other physiological parameters. Forty-seven adults (mean age 55.3 years) who were diagnosed with type 2 diabetes mellitus for less than 5 years (mean 2.1 years), had HbA1c ≥ 7% (mean 8.4%) and were not taking blood glucose lowering medications, were randomized to routine care or five 1-h instructional sessions of GEM. Assessments at baseline and 6 months included a physical exam, metabolic and lipid panels, and psychological questionnaires. The GEM intervention led to significant improvements in HbA1c (decreasing from 8.4 to 7.4% [69-57 mmol/mol] compared with 8.3 to 8.3% [68-68 mmol/mol] for routine care; Interaction ptype 2 diabetes mellitus. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

GEM: Performance and aging tests

International Nuclear Information System (INIS)

Cho, H.S.; Kadyk, J.; Han, S.H.; Hong, W.S.; Perez-Mendez, V.; Wenzel, W.; Pitts, K.; Martin, M.D.; Hutchins, J.B.

1999-01-01

Performance and aging tests have been done to characterize Gas Electron Multipliers (GEMs), including further design improvements such as a thicker GEM and a closed GEM. Since the effective GEM gain is typically smaller than the absolute GEM gain, due to trapping of avalanche electrons at the bottom GEM electrode, the authors performed field simulations and measurements for better understanding, and discuss methods to eliminate this effect. Other performance parameters of the GEMs are also presented, including absolute GEM gain, short-term and long-term gain stabilities

High-resolution laser-projection display system using a grating electromechanical system (GEMS)

Science.gov (United States)

Brazas, John C.; Kowarz, Marek W.

2004-01-01

Eastman Kodak Company has developed a diffractive-MEMS spatial-light modulator for use in printing and display applications, the grating electromechanical system (GEMS). This modulator contains a linear array of pixels capable of high-speed digital operation, high optical contrast, and good efficiency. The device operation is based on deflection of electromechanical ribbons suspended above a silicon substrate by a series of intermediate supports. When electrostatically actuated, the ribbons conform to the supporting substructure to produce a surface-relief phase grating over a wide active region. The device is designed to be binary, switching between a reflective mirror state having suspended ribbons and a diffractive grating state having ribbons in contact with substrate features. Switching times of less than 50 nanoseconds with sub-nanosecond jitter are made possible by reliable contact-mode operation. The GEMS device can be used as a high-speed digital-optical modulator for a laser-projection display system by collecting the diffracted orders and taking advantage of the low jitter. A color channel is created using a linear array of individually addressable GEMS pixels. A two-dimensional image is produced by sweeping the line image of the array, created by the projection optics, across the display screen. Gray levels in the image are formed using pulse-width modulation (PWM). A high-resolution projection display was developed using three 1080-pixel devices illuminated by red, green, and blue laser-color primaries. The result is an HDTV-format display capable of producing stunning still and motion images with very wide color gamut.

Design and implementation of the infrastructure of HadGEM3: the next-generation Met Office climate modelling system

Directory of Open Access Journals (Sweden)

H. T. Hewitt

2011-04-01

Full Text Available This paper describes the development of a technically robust climate modelling system, HadGEM3, which couples the Met Office Unified Model atmosphere component, the NEMO ocean model and the Los Alamos sea ice model (CICE using the OASIS coupler. Details of the coupling and technical solutions of the physical model (HadGEM3-AO are documented, in addition to a description of the configurations of the individual submodels. The paper demonstrates that the implementation of the model has resulted in accurate conservation of heat and freshwater across the model components. The model performance in early versions of this climate model is briefly described to demonstrate that the results are scientifically credible. HadGEM3-AO is the basis for a number of modelling efforts outside of the Met Office, both within the UK and internationally. This documentation of the HadGEM3-AO system provides a detailed reference for developers of HadGEM3-based climate configurations.

Gas amplification properties of GEM foils

International Nuclear Information System (INIS)

Beck, Jeannine

2009-01-01

In the framework of the detector concept International Linear Detector for the future accelerator project International Linear Collider, in which electrons and positrons at c. m. energies of 500 GeV are brought to collision, a time projection chamber shall be applied as central track detector. By the application of such a chamber as track detector a three-dimensional reconstruction of the track points is possible. If a particle passes the gas volume within the chamber it ionizises single gas atoms and the arising electrons move after the amplification in the GEM arrangement to the anode, so that a two-dimensional projection of the particle track is possible. The third dimension is calculated from the drift time of the electrons. The advances of this readout system consist therein that a better position resolution than by a multiwire proportional chamber is reached and the back-drifting ions can be strongly suppressed. Aim of this thesis are studies for a GEM module, which shall be used in a large TPC prototype. Concerning different requirements it is valid to compare different GEMs in order to can meet an optimal choice. In a small prototype present at DESY measurements for the acquisition of GEM-describing parameters were performed. The taking into operation of the test TPC was part of this thesis. Tracks were generated by a radioactive source, by means of which the gas amplification was determined. With the measurement arrangement gas-amplifier foils of different kind were compared in view of their amplification properties and their energy resolution power and systematically studied. Five different GEM performances were studied in the test TPC. These foils differ in their geometrical classification parameters, the fabrication process, or the materials. The GEMs produced at CERN possess in comparison with GEMs of the Japanese firm SciEnergy and a GEM of the US-American firm Tech-Etch the best amplification and resolution properties. Furthermore a new GEM framing

Development of a glass GEM

International Nuclear Information System (INIS)

Takahashi, Hiroyuki; Mitsuya, Yuki; Fujiwara, Takeshi; Fushie, Takashi

2013-01-01

Gas electron multipliers (GEMs) apply the concept of gas amplification inside many tiny holes, realizing robust and high-gain proportional counters. However, the polyimide substrate of GEMs prevents them from being used in sealed detector applications. We have fabricated and tested glass GEMs (G-GEMs) with substrates made of photosensitive glass material from the Hoya Corporation. We fabricated G-GEMs with several different hole diameters and thicknesses and successfully operated test G-GEMs with a 100×100 mm 2 effective area. The uniformity of our G-GEMs was good, and the energy resolution for 5.9 keV X-rays was 18.8% under uniform irradiation of the entire effective area. A gas gain by the G-GEMs of up to 6700 was confirmed with a gas mixture of Ar (70%)+CH 4 (30%). X-ray imaging using the charge division readout method was demonstrated

Design and Construction of a First Prototype Muon Tomography System with GEM Detectors for the Detection of Nuclear Contraband

CERN Document Server

AUTHOR|(CDS)2074269; Grasso, L; Locke, J B; Quintero, A; Mitra, D

2009-01-01

Current radiation portal monitors at sea ports and international borders that employ standard radiation detection techniques are not very sensitive to nuclear contraband that is well shielded to absorb emanating radiation. Muon Tomography (MT) based on the measurement of multiple scattering of atmospheric cosmic ray muons traversing cargo or vehicles that contain high-Z material is a promising passive interrogation technique for solving this problem. We report on the design and construction of compact Micro-Pattern Gas Detectors for a small prototype MT station. This station will employ 10 tracking stations based on 30cm x 30cm low-mass triple-GEM detectors with 2D readout. Due to the excellent spatial resolution of GEMs it is sufficient to use a gap of only a few cm between tracking stations. Together with the compact size of the GEM detectors this allows the GEM MT station to be an order of magnitude more compact than MT stations using traditional drift tubes. We present details of the production and assemb...

Gas Electron Multipliers: Development of large area GEMs and spherical GEMs

CERN Document Server

Duarte Pinto, Serge; Brock, Ian

2011-01-01

Gaseous radiation detectors have been a crucial part of high-energy physics instrumentation since the 1960s, when the first multiwire proportional counters were built. In the 1990s the first micropattern gas detectors (MPGDs) saw the light; with sub-millimeter feature sizes these novel detectors were faster and more accurate than their predecessors. The gas electron multiplier (GEM) is one of the most successful of these technologies. It is a charge multiplication structure made from a copper clad polymer foil, pierced with a regular and dense pattern of holes. I will describe the properties and the application of GEMs and GEM detectors, and the research and development I have done on this technology. Two of the main objectives were the development of large area GEMs (~m^2) for particle physics experiments and GEMs with a spherical shape for x-ray or neutron diffraction detectors. Both have been realized, and the new techniques involved are finding their way to applications in research and industry.

Gas electron multipliers. Development of large area GEMS and spherical GEMS

Energy Technology Data Exchange (ETDEWEB)

Pinto, Serge Duarte

2011-08-15

Gaseous radiation detectors have been a crucial part of high-energy physics instrumentation since the 1960s, when the first multiwire proportional counters were built. In the 1990s the first micropattern gas detectors (MPGDS) saw the light; with sub-millimeter feature sizes these novel detectors were faster and more accurate than their predecessors. The gas electron multiplier (GEM) is one of the most successful of these technologies. It is a charge multiplication structure made from a copper clad polymer foil, pierced with a regular and dense pattern of holes. I describe the properties and the application of GEMs and GEM. detectors, and the research and development I have done on this technology. Two of the main objectives were the development of large area GEMs ({proportional_to}m{sup 2}) for particle physics experiments and GEMs with a spherical shape for X-ray or neutron diffraction detectors. Both have been realized, and the new techniques involved are finding their way to applications in research and industry. (orig.)

Gas electron multipliers: Development of large area GEMS and spherical GEMS

International Nuclear Information System (INIS)

Pinto, Serge Duarte

2011-08-01

Gaseous radiation detectors have been a crucial part of high-energy physics instrumentation since the 1960s, when the first multiwire proportional counters were built. In the 1990s the first micropattern gas detectors (MPGDS) saw the light; with sub-millimeter feature sizes these novel detectors were faster and more accurate than their predecessors. The gas electron multiplier (GEM) is one of the most successful of these technologies. It is a charge multiplication structure made from a copper clad polymer foil, pierced with a regular and dense pattern of holes. I describe the properties and the application of GEMs and GEM. detectors, and the research and development I have done on this technology. Two of the main objectives were the development of large area GEMs (∝m 2 ) for particle physics experiments and GEMs with a spherical shape for X-ray or neutron diffraction detectors. Both have been realized, and the new techniques involved are finding their way to applications in research and industry. (orig.)

GEMS: Underwater spectrometer for long-term radioactivity measurements

Energy Technology Data Exchange (ETDEWEB)

Sartini, Ludovica, E-mail: ludovica.sartini@ingv.i [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Genoa University, Genoa (Italy); Simeone, Francesco; Pani, Priscilla [' Sapienza' University and Istituto Nazionale di Fisica Nucleare (INFN), Sect.Roma, Roma (Italy); Lo Bue, Nadia; Marinaro, Giuditta [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Grubich, Andry; Lobko, Alexander [Institute for Nuclear Problems (INP), Belarus State University, Minsk (Belarus); Etiope, Giuseppe [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Capone, Antonio [' Sapienza' University and Istituto Nazionale di Fisica Nucleare (INFN), Sect.Roma, Roma (Italy); Favali, Paolo [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Gasparoni, Francesco; Bruni, Federico [Tecnomare S.p.A., Venice (Italy)

2011-01-21

GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework for a development of a submarine telescope for neutrino detection (KM3NeT Design Study Project). The spectrometer is highly sensitive to gamma rays produced by {sup 40}K decays but it can detect other natural (e.g., {sup 238}U,{sup 232}Th) and anthropogenic radio-nuclides (e.g., {sup 137}Cs). GEMS was firstly tested and calibrated in the laboratory using known sources and it was successfully deployed for a long-term (6 months) monitoring at a depth of 3200 m in the Ionian Sea (Capo Passero, offshore Eastern Sicily). The instrument recorded data for the whole deployment period within the expected specifications. This monitoring provided, for the first time, a continuous time-series of radioactivity in deep-sea.

Development of entrepreneurship in Brazil based on indicators of the global entrepreneurship monitor (GEM

Directory of Open Access Journals (Sweden)

Ana Carolina Cozza Josende da Silva

2015-06-01

Full Text Available Entrepreneurship is very important in a society due to its influence with the growth and development of a country. The importance of studying and knowing the entrepreneurial activity and the entrepreneur's profile contributes positively to identify estimates of this activity and to clarify the future of this process. In this sense, this article presents the evolution of entrepreneurship in Brazil over the past 13 years, using for the study secondary data obtained from the GEM and IBGE researches, in which the search was conducted in documentary basis from 2001 to 2013. The results present a descriptive analysis of the Global Entrepreneurship Monitor entrepreneurship indicators (GEM concerning to the new entrepreneur rate and the rate of nascent entrepreneurs, growth of the Brazilian GDP related to entrepreneurship, entrepreneurship rate according to the entrepreneur stages (initial and established, initial entrepreneurs according to their motivation (by chance and necessity, by gender entrepreneurs, age, level of education. It was also carried out statistical analysis where the trend of the variables over time was verified by simple linear regression at the significance level of 5%. The study concludes that Brazil tends to present significant growth towards entrepreneurship, an advancement of the female contribution to the economy, increase of entrepreneurs because of more opportunities and stability in the existing businesses.

A 40 GByte/s read-out system for GEM

International Nuclear Information System (INIS)

Bowden, M.; Carrel, J.; Dorenbosch, J.; Kapoor, V.

1994-04-01

The preliminary design of the read-out system for the GEM (Gammas, Electrons, Muons) detector at the Superconducting Super Collider is presented. The system reads all digitized data from the detector data sources at a Level 1 trigger rate of up to 100 kHz. A total read-out bandwidth of 40 GBytes/s is available. Data are stored in buffers that are accessible for further event filtering by an on-line, processor farm. Data are transported to the farm only as they are needed by the higher-level trigger algorithms, leading to a reduced bandwidth requirement in the Data Acquisition System

Commissioning and integration testing of the DAQ system for the CMS GEM upgrade

CERN Document Server

Castaneda Hernandez, Alfredo Martin

2017-01-01

The CMS muon system will undergo a series of upgrades in the coming years to preserve and extend its muon detection capabilities during the High Luminosity LHC.The first of these will be the installation of triple-foil GEM detectors in the CMS forward region with the goal of maintaining trigger rates and preserving good muon reconstruction, even in the expected harsh environment.In 2017 the CMS GEM project is looking to achieve a major milestone in the project with the installation of 5 super-chambers in CMS; this exercise will allow for the study of services installation and commissioning, and integration with the rest of the subsystems for the first time. An overview of the DAQ system will be given with emphasis on the usage during chamber quality control testing, commissioning in CMS, and integration with the central CMS system.

A study of the effect of non-spherical dust particles on Geostationary Environment Monitoring Spectrometer (GEMS) aerosol optical properties retrievals

Science.gov (United States)

Go, S.; Kim, J.; KIM, M.; Choi, M.; Lim, H.

2017-12-01

Non-spherical assumption of particle shape has been used to replace the spherical assumption in the Geostationary Environment Monitoring Spectrometer (GEMS) aerosol optical properties retrievals for dust particles. GEMS aerosol retrieval algorithms are based on optimal estimation method to provide aerosol optical depth (AOD), single scattering albedo (SSA) at 443nm, and aerosol loading height (ALH) simultaneously as products. Considering computing time efficiency, the algorithm takes Look-Up Table (LUT) approach using Vector Linearized Discrete Ordinate Radiative Transfer code (VLIDORT), and aerosol optical properties for three aerosol types of absorbing fine aerosol (BC), dust and non-absorbing aerosol (NA) are integrated from AERONET inversion data, and fed into the LUT calculation. In this study, by applying the present algorithm to OMI top-of the atmosphere normalized radiance, retrieved AOD, SSA with both spherical and non-spherical assumptions have been compared to the surface AERONET observations at East Asia sites for 3 years from 2005 to 2007 to evaluate and quantify the effect of non-spherical dust particles on the satellite aerosol retrievals. The root-mean-square error (RMSE) in the satellite retrieved AOD have been slightly reduced as a result of adopting the non-spherical assumption in the GEMS aerosol retrieval algorithm. For SSA, algorithm tested with spheroid models on dust particle shows promising results for the improved SSA. In terms of ALH, the results are qualitatively compared with CALIOP products, and shows consistent variation. This result suggests the importance of taking into account the effects of non-sphericity in the retrieval of dust particles from GEMS measurements.

Gaseous Electron Multiplier (GEM) Detectors

Science.gov (United States)

Gnanvo, Kondo

2017-09-01

Gaseous detectors have played a pivotal role as tracking devices in the field of particle physics experiments for the last fifty years. Recent advances in photolithography and micro processing techniques have enabled the transition from Multi Wire Proportional Chambers (MWPCs) and Drift Chambers to a new family of gaseous detectors refer to as Micro Pattern Gaseous Detectors (MPGDs). MPGDs combine the basic gas amplification principle with micro-structure printed circuits to provide detectors with excellent spatial and time resolution, high rate capability, low material budget and high radiation tolerance. Gas Electron Multiplier (GEMs) is a well-established MPGD technology invented by F. Sauli at CERN in 1997 and deployed various high energy physics (HEP) and nuclear NP experiment for tracking systems of current and future NP experiments. GEM detector combines an exceptional high rate capability (1 MHz / mm2) and robustness against harsh radiation environment with excellent position and timing resolution performances. Recent breakthroughs over the past decade have allowed the possibility for large area GEMs, making them cost effective and high-performance detector candidates to play pivotal role in current and future particle physics experiments. After a brief introduction of the basic principle of GEM technology, I will give a brief overview of the GEM detectors used in particle physics experiments over the past decades and especially in the NP community at Thomas Jefferson National Laboratory (JLab) and Brookhaven National Laboratory (BNL). I will follow by a review of state of the art of the new GEM development for the next generation of colliders such as Electron Ion Collider (EIC) or High Luminosity LHC and future Nuclear Physics experiments. I will conclude with a presentation of the CERN-based RD51 collaboration established in 2008 and its major achievements regarding technological developments and applications of MPGDs.

Quality control for the first large areas of triple-GEM chambers for the CMS endcaps

Science.gov (United States)

Abbaneo, D.; Abbas, M.; Abbrescia, M.; Abi Akl, M.; Aboamer, O.; Acosta, D.; Ahmad, A.; Ahmed, W.; Aleksandrov, A.; Altieri, P.; Asawatangtrakuldee, C.; Aspell, P.; Assran, Y.; Awan, I.; Bally, S.; Ban, Y.; Banerjee, S.; Barashko, V.; Barria, P.; Bencze, G.; Beni, N.; Benussi, L.; Bhopatkar, V.; Bianco, S.; Bos, J.; Bouhali, O.; Braghieri, A.; Braibant, S.; Buontempo, S.; Calabria, C.; Caponero, M.; Caputo, C.; Cassese, F.; Castaneda, A.; Cauwenbergh, S.; Cavallo, F. R.; Celik, A.; Choi, M.; Choi, S.; Christiansen, J.; Cimmino, A.; Colafranceschi, S.; Colaleo, A.; Conde Garcia, A.; Czellar, S.; Dabrowski, M. M.; De Lentdecker, G.; De Oliveira, R.; de Robertis, G.; Dildick, S.; Dorney, B.; Endroczi, G.; Errico, F.; Fenyvesi, A.; Ferry, S.; Furic, I.; Giacomelli, P.; Gilmore, J.; Golovtsov, V.; Guiducci, L.; Guilloux, F.; Gutierrez, A.; Hadjiiska, R. M.; Hauser, J.; Hoepfner, K.; Hohlmann, M.; Hoorani, H.; Iaydjiev, P.; Jeng, Y. G.; Kamon, T.; Karchin, P.; Korytov, A.; Krutelyov, S.; Kumar, A.; Kim, H.; Lee, J.; Lenzi, T.; Litov, L.; Loddo, F.; Madorsky, A.; Maerschalk, T.; Maggi, M.; Magnani, A.; Mal, P. K.; Mandal, K.; Marchioro, A.; Marinov, A.; Majumdar, N.; Merlin, J. A.; Mitselmakher, G.; Mohanty, A. K.; Mohapatra, A.; Molnar, J.; Muhammad, S.; Mukhopadhyay, S.; Naimuddin, M.; Nuzzo, S.; Oliveri, E.; Pant, L. M.; Paolucci, P.; Park, I.; Passeggio, G.; Pavlov, B.; Philipps, B.; Piccolo, D.; Postema, H.; Puig Baranac, A.; Radi, A.; Radogna, R.; Raffone, G.; Ranieri, A.; Rashevski, G.; Riccardi, C.; Rodozov, M.; Rodrigues, A.; Ropelewski, L.; RoyChowdhury, S.; Ryu, G.; Ryu, M. S.; Safonov, A.; Salva, S.; Saviano, G.; Sharma, A.; Sharma, A.; Sharma, R.; Shah, A. H.; Shopova, M.; Sturdy, J.; Sultanov, G.; Swain, S. K.; Szillasi, Z.; Talvitie, J.; Tatarinov, A.; Tuuva, T.; Tytgat, M.; Vai, I.; Van Stenis, M.; Venditti, R.; Verhagen, E.; Verwilligen, P.; Vitulo, P.; Volkov, S.; Vorobyev, A.; Wang, D.; Wang, M.; Yang, U.; Yang, Y.; Yonamine, R.; Zaganidis, N.; Zenoni, F.; Zhang, A.

2018-02-01

The CMS Collaboration plans to equip the very forward muon system with triple-GEM detectors that can withstand the environment of the High-Luminosity LHC. This project is at the final stages of R&D and moving to production. An unprecedented large area of several 100 m2 are to be instrumented with GEM detectors which will be produced in six different sites around the world. A common construction and quality control procedure is required to ensure the performance of each detector. The quality control steps will include optical inspection, cleaning and baking of all materials and parts used to build the detector, leakage current tests of the GEM foils, high voltage tests, gas leak tests of the chambers and monitoring pressure drop vs. time, gain calibration to know the optimal operation region of the detector, gain uniformity tests, and studying the efficiency, noise and tracking performance of the detectors in a cosmic stand using scintillators.

Quality control for the first large areas of triple-GEM chambers for the CMS endcaps

Directory of Open Access Journals (Sweden)

Abbaneo D.

2018-01-01

Full Text Available The CMS Collaboration plans to equip the very forward muon system with triple-GEM detectors that can withstand the environment of the High-Luminosity LHC. This project is at the final stages of R&D and moving to production. An unprecedented large area of several 100 m2 are to be instrumented with GEM detectors which will be produced in six different sites around the world. A common construction and quality control procedure is required to ensure the performance of each detector. The quality control steps will include optical inspection, cleaning and baking of all materials and parts used to build the detector, leakage current tests of the GEM foils, high voltage tests, gas leak tests of the chambers and monitoring pressure drop vs. time, gain calibration to know the optimal operation region of the detector, gain uniformity tests, and studying the efficiency, noise and tracking performance of the detectors in a cosmic stand using scintillators.

Quality control for the first large areas of triple-GEM chambers for the CMS endcaps

CERN Document Server

AUTHOR|(CDS)2068936; Abbas, M.; Abbrescia, M.; Abi Akl, M.; Aboamer, O.; Acosta, D.; Ahmad, A.; Ahmed, W.; Aleksandrov, A.; Altieri, P.; Asawatangtrakuldee, C.; Aspell, P.; Assran, Y.; Awan, I.; Bally, S.; Ban, Y.; Banerjee, S.; Barashko, V.; Barria, P.; Bencze, G.; Beni, N.; Benussi, L.; Bhopatkar, V.; Bianco, S.; Bos, J.; Bouhali, O.; Braghieri, A.; Braibant, S.; Buontempo, S.; Calabria, C.; Caponero, M.; Caputo, C.; Cassese, F.; Castaneda, A.; Cauwenbergh, S.; Cavallo, F.R.; Celik, A.; Choi, M.; Choi, S.; Christiansen, J.; Cimmino, A.; Colafranceschi, S.; Colaleo, A.; Conde Garcia, A.; Czellar, S.; Dabrowski, M.M.; De Lentdecker, G.; De Oliveira, R.; de Robertis, G.; Dildick, S.; Dorney, B.; Endroczi, G.; Errico, F.; Fenyvesi, A.; Ferry, S.; Furic, I.; Giacomelli, P.; Gilmore, J.; Golovtsov, V.; Guiducci, L.; Guilloux, F.; Gutierrez, A.; Hadjiiska, R.M.; Hauser, J.; Hoepfner, K.; Hohlmann, M.; Hoorani, H.; Iaydjiev, P.; Jeng, Y.G.; Kamon, T.; Karchin, P.; Korytov, A.; Krutelyov, S.; Kumar, A.; Kim, H.; Lee, J.; Lenzi, T.; Litov, L.; Loddo, F.; Madorsky, A.; Maerschalk, T.; Maggi, M.; Magnani, A.; Mal, P.K.; Mandal, K.; Marchioro, A.; Marinov, A.; Majumdar, N.; Merlin, J.A.; Mitselmakher, G.; Mohanty, A.K.; Mohapatra, A.; Molnar, J.; Muhammad, S.; Mukhopadhyay, S.; Naimuddin, M.; Nuzzo, S.; Oliveri, E.; Pant, L.M.; Paolucci, P.; Park, I.; Passeggio, G.; Pavlov, B.; Philipps, B.; Piccolo, D.; Postema, H.; Puig Baranac, A.; Radi, A.; Radogna, R.; Raffone, G.; Ranieri, A.; Rashevski, G.; Riccardi, C.; Rodozov, M.; Rodrigues, A.; Ropelewski, L.; RoyChowdhury, S.; Ryu, G.; Ryu, M.S.; Safonov, A.; Salva, S.; Saviano, G.; Sharma, A.; Sharma, A.; Sharma, R.; Shah, A.H.; Shopova, M.; Sturdy, J.; Sultanov, G.; Swain, S.K.; Szillasi, Z.; Talvitie, J.; Tatarinov, A.; Tuuva, T.; Vai, I.; Van Stenis, M.; Venditti, R.; Verhagen, E.; Verwilligen, P.; Vitulo, P.; Volkov, S.; Vorobyev, A.; Wang, D.; Wang, M.; Yang, U.; Yang, Y.; Yonamine, R.; Zaganidis, N.; Zenoni, F.; Zhang, A.

2015-01-01

The CMS Collaboration plans to equip the very forward muon system with triple-GEM detectors that can withstand the environment of the High-Luminosity LHC. This project is at the final stages of R&D and moving to production. An unprecedented large area of several 100 m2 are to be instrumented with GEM detectors which will be produced in six different sites around the world. A common construction and quality control procedure is required to ensure the performance of each detector. The quality control steps will include optical inspection, cleaning and baking of all materials and parts used to build the detector, leakage current tests of the GEM foils, high voltage tests, gas leak tests of the chambers and monitoring pressure drop vs. time, gain calibration to know the optimal operation region of the detector, gain uniformity tests, and studying the efficiency, noise and tracking performance of the detectors in a cosmic stand using scintillators.

Graphics gems

CERN Document Server

Glassner, Andrew S

1993-01-01

""The GRAPHICS GEMS Series"" was started in 1990 by Andrew Glassner. The vision and purpose of the Series was - and still is - to provide tips, techniques, and algorithms for graphics programmers. All of the gems are written by programmers who work in the field and are motivated by a common desire to share interesting ideas and tools with their colleagues. Each volume provides a new set of innovative solutions to a variety of programming problems.

Graphics Gems III IBM version

CERN Document Server

Kirk, David

1994-01-01

This sequel to Graphics Gems (Academic Press, 1990), and Graphics Gems II (Academic Press, 1991) is a practical collection of computer graphics programming tools and techniques. Graphics Gems III contains a larger percentage of gems related to modeling and rendering, particularly lighting and shading. This new edition also covers image processing, numerical and programming techniques, modeling and transformations, 2D and 3D geometry and algorithms,ray tracing and radiosity, rendering, and more clever new tools and tricks for graphics programming. Volume III also includes a

An aging study of triple GEMs in Ar-CO sub 2

CERN Document Server

Guirl, L; May, J; Miyamoto, J; Shipsey, I

2002-01-01

An aging study was performed using triple GEMs and a print circuit board (PCB) with an intense X-ray radiation source. The GEM chamber consists of three identical GEMs and a large gas gain (6000) was shared by them. The chamber and its gas circulation line was carefully cleaned and constructed with stainless steel materials. The detector was irradiated continuously about 750 h without interruption until a large amount of charge was accumulated. A single-wire counter served as a monitoring device to check the beam and ambient conditions. The quality of the Ar-CO sub 2 gas was checked by gas chromatography and no measurable amount of hydrocarbons were found. 27 mC/mm sup 2 was accumulated with no noticeable degradation and no deposit or discoloration was found in an optical check.

SUPERCOLLIDER: A GEM of a detector

International Nuclear Information System (INIS)

Anon.

1993-01-01

Now being prepared as a major experimental facility for the 87- kilometre Superconducting Supercollider (SSC) being built in Ellis County, Texas, is the GEM detector project. GEM thus becomes the companion to the Solenoidal Detector Collaboration (SDC), the first major SSC detector to emerge (March 1992, page 13). This is in keeping with the SSC Laboratory's aim of two major detectors with overlapping and complementary strengths. GEM is designed to observe all SSC signatures, with emphasis on precise measurement of electrons, photons and muons. Hence the name GEM - ''Gammas, Electrons and Muons.'' Design goals are clean signatures for leptons, jets, and missing transverse energy, maximum sensitivity to narrow resonances, and low backgrounds. Also important is maintaining significant capability at high luminosity (10 34 cm -2 s -1 ). GEM has some distinctive features. A key concept is the exterior magnet, surrounding all detector elements. Inside the magnet are a muon tracking system, a precision calorimeter, and a compact central tracker. This allows the muon momentum to be measured the air of the radiation shielded area outside the thick calorimeter, giving both high precision and robustness at high luminosity. A large magnet gives a large lever arm (at least 4 m) for precise muon momentum measurement. Placing the magnet outside also minimizes the material between tracker and calorimeters, so that the calorimeters are limited only by their inherent resolutions

Graphics gems V (Macintosh version)

CERN Document Server

Paeth, Alan W

1995-01-01

Graphics Gems V is the newest volume in The Graphics Gems Series. It is intended to provide the graphics community with a set of practical tools for implementing new ideas and techniques, and to offer working solutions to real programming problems. These tools are written by a wide variety of graphics programmers from industry, academia, and research. The books in the series have become essential, time-saving tools for many programmers.Latest collection of graphics tips in The Graphics Gems Series written by the leading programmers in the field.Contains over 50 new gems displaying some of t

Microstructured boron foil scintillating G-GEM detector for neutron imaging

Energy Technology Data Exchange (ETDEWEB)

Fujiwara, Takeshi, E-mail: fujiwara-t@aist.go.jp [Research Institute for Measurement and Analytical Instrumentation, Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan); Center for Advanced Photonics, Neutron Beam Technology Team, RIKEN, Saitama (Japan); Bautista, Unico [Department of Nuclear Engineering and Management, The University of Tokyo, Tokyo (Japan); Philippine Nuclear Research Institute-Department of Science and Technology (PNRI-DOST), Commonwealth Avenue, Diliman, Quezon City (Philippines); Mitsuya, Yuki [Nuclear Professional School, The University of Tokyo, Tokai-mura, Naka-gun, Ibaraki (Japan); Takahashi, Hiroyuki [Department of Nuclear Engineering and Management, The University of Tokyo, Tokyo (Japan); Yamada, Norifumi L. [Neutron Science Laboratory, Institute of Material Structure Science, High Energy Accelerator Research Organization (KEK) (Japan); Otake, Yoshie; Taketani, Atsushi [Center for Advanced Photonics, Neutron Beam Technology Team, RIKEN, Saitama (Japan); Uesaka, Mitsuru [Nuclear Professional School, The University of Tokyo, Tokai-mura, Naka-gun, Ibaraki (Japan); Toyokawa, Hiroyuki [Research Institute for Measurement and Analytical Instrumentation, Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan)

2016-12-01

In this study, a new simple neutron imaging gaseous detector was successfully developed by combining a micro-structured {sup 10}B foil, a glass gas electron multiplier (G-GEM), and a mirror–lens–charge-coupled device (CCD)–camera system. The neutron imaging system consists of a chamber filled with Ar/CF{sub 4} scintillating gas mixture. Inside this system, the G-GEM is mounted for gas multiplication. The neutron detection in this system is based on the reaction between {sup 10}B and neutrons. A micro-structured {sup 10}B is developed to overcome the issue of low detection efficiency. Secondary electrons excite Ar/CF{sub 4} gas molecules, and high-yield visible photons are emitted from those excited gas molecules during the gas electron multiplication process in the G-GEM holes. These photons are easily detected by a mirror–lens–CCD–camera system. A neutron radiograph is then simply formed. We obtain the neutron images of different materials with a compact accelerator-driven neutron source. We confirm that the new scintillating G-GEM-based neutron imager works properly with low gamma ray sensitivity and exhibits a good performance as a new simple digital neutron imaging device.

Development of the DAQ System of Triple-GEM Detectors for the CMS Muon Spectrometer Upgrade at LHC

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00387583

The Gas Electron Multiplier (GEM) upgrade project aims at improving the performance of the muon spectrometer of the Compact Muon Solenoid (CMS) experiment which will suffer from the increase in luminosity of the Large Hadron Collider (LHC). After a long technical stop in 2019-2020, the LHC will restart and run at a luminosity of 2 × 1034 cm−2 s−1, twice its nominal value. This will in turn increase the rate of particles to which detectors in CMS will be exposed and affect their performance. The muon spectrometer in particular will suffer from a degraded detection efficiency due to the lack of redundancy in its most forward region. To solve this issue, the GEM collaboration proposes to instrument the first muon station with Triple-GEM detectors, a technology which has proven to be resistant to high fluxes of particles. Within the GEM collaboration, the Data Acquisition (DAQ) subgroup is in charge of the development of the electronics and software of the DAQ system of the detectors. This thesis presents th...

GEMS Revealed: Spectrum Imaging of Aggregate Grains in Interplanetary Dust

Science.gov (United States)

Keller, L. P.; Messenger, S.; Christoffersen, R.

2005-01-01

Anhydrous interplanetary dust particles (IDPs) of cometary origin contain abundant materials that formed in the early solar nebula. These materials were transported outward and subsequently mixed with molecular cloud materials and presolar grains in the region where comets accreted [1]. GEMS (glass with embedded metal and sulfides) grains are a major component of these primitive anhydrous IDPs, along with crystalline Mg-rich silicates, Fe-Ni sulfides, carbonaceous material, and other trace phases. Some GEMS grains (5%) are demonstrably presolar based on their oxygen isotopic compositions [2]. However, most GEMS grains are isotopically solar and have bulk chemical compositions that are incompatible with inferred compositions of interstellar dust, suggesting a solar system origin [3]. An alternative hypothesis is that GEMS grains represent highly irradiated interstellar grains whose oxygen isotopic compositions were homogenized through processing in the interstellar medium (ISM) [4]. We have obtained the first quantitative X-ray maps (spectrum images) showing the distribution of major and minor elements in individual GEMS grains. Nanometer-scale chemical maps provide critical data required to evaluate the differing models regarding the origin of GEMS grains.

Complete Tem-Tomography: 3D Structure of Gems Cluster

Science.gov (United States)

Matsuno, J.; Miyake, A.; Tsuchiyama, A.; Messenger, S.; Nakamura-Messenger, K.

2015-01-01

GEMS (glass with embedded metal and sulfide) grains in interplanetary dust particles (IDPs) are considered to be one of the ubiquitous and fundamental building blocks of solids in the Solar System. They have been considered to be interstellar silicate dust that survived various metamorphism or alteration processes in the protoplanetary disk but the elemental and isotopic composition measurements suggest that most of them have been formed in the protoplanetary disk as condensates from high temperature gas. This formation model is also supported by the formation of GEMS-like grains with respect to the size, mineral assemblage, texture and infrared spectrum by condensation experiments from mean GEMS composition materials. Previous GEMS studies were performed only with 2D observation by transmission electron microscopy (TEM) or scanning TEM (STEM). However, the 3D shape and structure of GEMS grains and the spatial distribution of Fe/FeS's has critical information about their formation and origin. Recently, the 3D structure of GEMS grains in ultrathin sections of cluster IDPs was revealed by electron tomography using a TEM/STEM (JEM-2100F, JEOL). However, CT images of thin sections mounted on Cu grids acquired by conventional TEM-tomography are limited to low tilt angles (e. g., less than absolute value of 75 deg. In fact, previous 3D TEM observations of GEMS were affected by some artifacts related to the limited tilt range in the TEM used. Complete tomographic images should be acquired by rotating the sample tilt angle over a range of more than absolute value of 80 deg otherwise the CT images lose their correct structures. In order to constrain the origin and formation process of GEMS grains more clearly, we performed complete electron tomography for GEMS grains. Here we report the sample preparation method we have developed for this study, and the preliminary results.

Mexican gems as thermoluminescent dosimeters

International Nuclear Information System (INIS)

Azorin N, J.

1979-01-01

The possibility of using naturally ocurring mexican gems as thermoluminescent dosimeters (TLD) was investigated. Twelve types of gems were irradiated with X and gamma rays in order to determinate their dosimetric properties. Three of these gems showed favorable thermoluminescent characteristics compared with commercial thermoluminescent dosimeters. The plots of their thermoluminescent response as a function of gamma dose are straight lines on full log paper in the dose range 10 -2 to 10 2 Gy. The energy dependence is very strong to low energies of the radiation. Their fading was found to be about 5%/yr. and they may be annealed as reused without loss in sensitivity. Therefore, these gems can be used as X and gamma radiation dosimeters. (author)

Reactivity worth of gas expansion modules (GEMs) in the fast flux test facility

International Nuclear Information System (INIS)

Campbell, L.R.; Nelson, J.V.; Burke, T.M.; Rawlins, J.A.; Daughtry, J.W.; Bennett, R.A.

1986-01-01

A new passive shutdown device called a gas expansion module (GEM) has been developed at Hanford Engineering Development Laboratory to insert negative reactivity during a primary system loss of flow in a liquid-metal reactor (LMR). A GEM is a hollow removable core component which is sealed at the top and open at the bottom. An argon gas bubble trapped inside the assembly expands when core inlet pressure decreases (caused by a flow reduction) and expels sodium from the assembly. The GEMs are designed so that the level of the liquid-sodium primary system coolant within a GEM is above the top of the core when the primary pumps are operating at full flow and is below the bottom of the core when the primary pumps are off. When a GEM is placed at the boundary of the core and radial reflector, the drop in sodium level increases core neutron leakage and inserts negative reactivity. The results of these measurements confirm the effectiveness of GEMs in adding negative reactivity in loss-of-flow situations. It follows, therefore, that the inherent safety of LMRs, comparable in size to the FFTF, can be enhanced by the use of GEMs

Possible Gems and Ultra-Fine Grained Polyphase Units in Comet Wild 2.

Science.gov (United States)

Gainsforth, Z.; Butterworth, A. L.; Jilly-Rehak, C. E.; Westphal, A. J.; Brownlee, D. E.; Joswiak, D.; Ogliore, R. C.; Zolensky, M. E.; Bechtel, H. A.; Ebel, D. S.;

3D Observation of GEMS by Electron Tomography

Science.gov (United States)

Matsuno, Junya; Miyake, Akira; Tsuchiyama, Akira; Nakamura-Messenger, Keiko; Messenger, Scott

2014-01-01

sample thickness ) approx. or greater than 50 nm). Three cluster IDPs (L2036AA5 cluster4, L2009L8 cluster 13 and W726A2) were used for the observations. ID W726A2 was collected without silicon oil, which is ordinary used to collect IDPs, so this sample has no possibility of contaminations caused by silicon oil or solvent to rinse it [6]. The samples were embedded in epoxy risin and sliced into ultrathin sections (50-300 nm) using an ultramicotome. The sections were observed by BF-TEM and HAADF-STEM (high angle annular dark field-scanning TEM) modes. Images were obtained by rotating the sample tilt angle over a range of +/- 65 deg in 1 deg steps. The obtained images were reconstructed to slice images. Mineral phases in the slice images were estimated by comparing with a 2D elemental map obtained by an EDS (energy dispersive X-ray spectroscopy) system equipped in the TEM/STEM. Careful examination of the slice images confirmed that iron grains are embedded in the amorphous silicate matrix of the GEMS grains, but sulfide grains were mainly present on the surface of the amorphous silicate. These results are consistent with the model that GEMS grains formed as condensates [3,5], although more data are needed to conclude the origin of GEMS grains. The present study is the first successful example adapting the electron tomography to the IDPs. This type of analysis will be important for planetary material sciences in the future.

Test beam studies of Gas Electron Multiplier (GEM) detectors for the upgrade of CMS endcap muon system

CERN Document Server

Sharma, Ram Krishna

2017-01-01

The High Luminosity LHC (HL-LHC) will provide exceptional high instantaneous and integrated luminosity. The forward region $\\mid \\eta \\mid \\geq 1.5$ of the CMS detector will face extremely high particle rates in tens of $KHz/cm^{2}$ and hence it will affect the momentum resolution and longevity of the muon detectors. To overcome these issues the CMS collaboration has decided to install new large size rate capable Triple Gas Electron Multiplier (GEM) detectors in the forward region of CMS muon system. The first set of Triple GEM detectors will be installed in the GE1/1 region $(1.5 \\leq \\eta \\leq 2.2)$ of muon endcap during the LS2 of the LHC and the next one will be installed in the GE2/1 region $(1.6 \\leq \\eta \\leq 2.5)$, during the LS3. Towards this goal, full-size CMS Triple GEM prototype chambers have been fabricated and put under the test beam at the CERN SPS test beam facility. The GEM detectors were operated with two gas mixtures $Ar/CO_{2}$ (70/30) and $Ar/CO_{2}/CF_{4}$ (40/15/45). In 2014 and 2016, ...

Study of long-term operation of triple-GEM detectors for the high rate environment in CMS

CERN Document Server

Merlin, Jeremie Alexandre

2013-01-01

The CMS GEM collaboration is working on the possible instrumentation of the high-eta region of the CMS Endcap with Gas Electron Multiplier (GEM) detectors, a technology capable to sustain the hostile environment that will be encountered at the high-luminosity LHC. To ensure the long-term operation of large triple-GEM detectors in the CMS experiment, we are performing a set of studies in order to measure and understand the aging effect of triple-GEM Muon chambers. The aging includes all the processes that lead to a significant degradation of the performances of the detector gain drop, non-uniformity, dark current, discharges and resolution loss. The project is focused on monitoring continuously the response of the detector when irradiated by a source of Cs 137 at CERN in the Gamma Irradiation Facility (GIF). Moreover, the new technology employed for stretching the GEM foils, so called NS2, introduces new, carefully chosen materials and components in the detectors. Outgassing tests are performed in order to va...

Development of a Diehard GEM using PTFE insulator substrate

International Nuclear Information System (INIS)

Wakabayashi, M; Tamagawa, T; Takeuchi, Y; Aoki, K; Taketani, A; Komiya, K; Hamagaki, H

2014-01-01

We have developed the gas electron multiplier (GEM) using polytetrafluoroethylene (PTFE) insulator substrate (PTFE-GEM). Carbonization on insulator layer by discharges shorts the GEM electrodes, causing permanent breakdown. Since PTFE is hard to be carbonized against arc discharges, PTFE-GEM is expected to be robust against breakdown. Gains as high as 2.6 × 10 4 were achieved with PTFE-GEM (50 μm thick) in Ar/CO 2 = 70%/30% gas mixture at V GEM = 730 V. PTFE-GEM never showed a permanent breakdown even after suffering more than 40000 times discharges during the experiment. The result demonstrates that PTFE-GEM is really robust against discharges. We conclude that PTFE is an excellent insulator material for the GEM productions

Development of a Diehard GEM using PTFE insulator substrate

OpenAIRE

Wakabayashi, M.; Komiya, K.; Tamagawa, T.; Takeuchi, Y.; Aoki, K.; Taketani, A.; Hamagaki, H.

2014-01-01

We have developed the gas electron multiplier (GEM) using polytetrafluoroethylene (PTFE) insulator substrate (PTFE-GEM). Carbonization on insulator layer by discharges shorts the GEM electrodes, causing permanent breakdown. Since PTFE is hard to be carbonized against arc discharges, PTFE-GEM is expected to be robust against breakdown. Gains as high as 2.6x10^4 were achieved with PTFE-GEM (50 um thick) in Ar/CO2 = 70%/30% gas mixture at V_GEM = 730V. PTFE-GEM never showed a permanent breakdown...

Fine-pitch glass GEM for high-resolution X-ray imaging

International Nuclear Information System (INIS)

Fujiwara, T.; Toyokawa, H.; Mitsuya, Y.

2016-01-01

We have developed a fine-pitch glass gas electron multiplier (G-GEM) for high-resolution X-ray imaging. The fine-pitch G-GEM is made of a 400 μm thick photo-etchable glass substrate with 150 μm pitch holes. It is fabricated using the same wet etching technique as that for the standard G-GEM. In this work, we present the experimental results obtained with a single fine-pitch G-GEM with a 50 × 50 mm 2 effective area. We recorded an energy resolution of 16.2% and gas gain up to 5,500 when the detector was irradiated with 5.9 keV X-rays. We present a 50 × 50 mm 2 X-ray radiograph image acquired with a scintillation gas and optical readout system.

Progress on large area GEMs (VCI 2010)

CERN Document Server

Villa, Marco; Alfonsi, Matteo; Brock, Ian; Croci, Gabriele; David, Eric; de Oliveira, Rui; Ropelewski, Leszek; Taureg, Hans; van Stenis, Miranda

2011-01-01

The Gas Electron Multiplier (GEM) manufacturing technique has recently evolved to allow the production of large area GEMs. A novel approach based on single mask photolithography eliminates the mask alignment issue, which limits the dimensions in the traditional double mask process. Moreover, a splicing technique overcomes the limited width of the raw material. Stretching and handling issues in large area GEMs have also been addressed. Using the new improvements it was possible to build a prototype triple-GEM detector of ~ 2000 cm2 active area, aimed at an application for the TOTEM T1 upgrade. Further refinements of the single mask technique give great control over the shape of the GEM holes and the size of the rims, which can be tuned as needed. In this framework, simulation studies can help to understand the GEM behavior depending on the hole shape.

Performance of gas electron multiplier (GEM) detector

International Nuclear Information System (INIS)

Han, S. H.; Moon, B. S.; Kim, Y. K.; Chung, C. E.; Kang, H. D.; Cho, H. S.

2002-01-01

We have investigated in detail the operating properties of Gas Electron Multiplier (GEM) detectors with a double conical and a cylindrical structure in a wide range of external fields and GEM voltages. With the double conical GEM, the gain gradually increased with time by 10%; whereas this surface charging was eliminated with the cylindrical GEM. Effective gains above 1000 were easily observed over a wide range of collection field strengths in a gas mixture of Ar/CO 2 (70/30). The transparency and electron collection efficiency were found to depend on the ratio of external field and the applied GEM voltage; the mutual influence of both drift and collection fields was found to be trivial

HydroGEM, a hydrogen fuelled utility vehicle. Case study

International Nuclear Information System (INIS)

Hoevenaars, A.J.; Kraaij, G.J.; De Bruijne, M.; Weeda, M.

2010-02-01

This report describes the conversion of a Global Electric Motorcars (GEM, a Chrysler company) electric utility vehicle into a Fuel Cell Vehicle called HydroGEM, at the Energy research Centre of the Netherlands (ECN). The report is prepared as a case study within the framework of Task 18 on 'Evaluation of Integrated Hydrogen Systems' of the IEA Hydrogen Implementing Agreement. The vehicle's fuel cell system was designed in 2005, manufactured and built into the vehicle in 2006 and operated from 2007 onwards. The design-choices, assembly, operation and maintenance-issues are presented and discussed.

GEM Technical Design Report

Energy Technology Data Exchange (ETDEWEB)

1993-07-31

The GEM collaboration was formed in June 1991 to develop a major detector for the SSC. The primary physics objectives of GEM are those central to the motivation for the SSC, to study high p{sub T} physics - exemplified by the search for Higgs bosons - and to search for new physics beyond the standard model. The authors present in this Technical Design Report (TDR) a detector with broad capabilities for the discovery and subsequent study of electroweak symmetry breaking, the origin of mass and flavor, and other physics requiring precise measurements of gammas, electrons, and muons - hence the name, GEM. In addition, as a design goal, they have taken care to provide the robustness needed to do the physics that requires high luminosity. Finally, good coverage and hermeticity allow the detection of missing transverse energy, E{sub T}. The GEM design emphasizes clean identification and high resolution measurement of the primary physics signatures for high p{sub T} physics. The approach is to make precise energy measurements that maximize the sensitivity to rare narrow resonances, to detect the elementary interaction products (quarks, leptons, and photons), and to build in the features required to reduce backgrounds.

GEM Technical Design Report

International Nuclear Information System (INIS)

1993-01-01

The GEM collaboration was formed in June 1991 to develop a major detector for the SSC. The primary physics objectives of GEM are those central to the motivation for the SSC, to study high p T physics - exemplified by the search for Higgs bosons - and to search for new physics beyond the standard model. The authors present in this Technical Design Report (TDR) a detector with broad capabilities for the discovery and subsequent study of electroweak symmetry breaking, the origin of mass and flavor, and other physics requiring precise measurements of gammas, electrons, and muons - hence the name, GEM. In addition, as a design goal, they have taken care to provide the robustness needed to do the physics that requires high luminosity. Finally, good coverage and hermeticity allow the detection of missing transverse energy, E T . The GEM design emphasizes clean identification and high resolution measurement of the primary physics signatures for high p T physics. The approach is to make precise energy measurements that maximize the sensitivity to rare narrow resonances, to detect the elementary interaction products (quarks, leptons, and photons), and to build in the features required to reduce backgrounds

How to reduce the ion feedback in GEM

International Nuclear Information System (INIS)

Park, S. H.; Kang, S. M.; Kim, Y. G.

2003-01-01

The feedback of positive ions in Gas Electron Multiplier(GEM) has to be suppressed to reduce the photocathode degradation in GEM photomultiplier and to prevent the field distortion in a Time Projection Chamber(TPC). The ion feedback dependency on the drift electric field, the transfer field, the asymmetry in the voltages across the GEM, and the effective gain was measured in various gases. The ion feedback is sensitive to the drift field and the effective gain. A model prediction of the ion feedback in multiple GEM was compared with the measurement. The ion gating method, which is being studyed in TPC, is introduced to reduce the ion feedback in GEM. With Maxwell and Garfield calculation, we obtained the reduction of the ion feedback by placing the wires between the drift plate and the GEM. We calculated the depedency of the ion feedback with respect to the bias voltage on the wire, the distance between the wires, and the distance between the wire and the GEM

GEM simulation methods development

International Nuclear Information System (INIS)

Tikhonov, V.; Veenhof, R.

2002-01-01

A review of methods used in the simulation of processes in gas electron multipliers (GEMs) and in the accurate calculation of detector characteristics is presented. Such detector characteristics as effective gas gain, transparency, charge collection and losses have been calculated and optimized for a number of GEM geometries and compared with experiment. A method and a new special program for calculations of detector macro-characteristics such as signal response in a real detector readout structure, and spatial and time resolution of detectors have been developed and used for detector optimization. A detailed development of signal induction on readout electrodes and electronics characteristics are included in the new program. A method for the simulation of charging-up effects in GEM detectors is described. All methods show good agreement with experiment

The gas electron multiplier (GEM)

CERN Document Server

Bouclier, Roger; Dominik, Wojciech; Hoch, M; Labbé, J C; Million, Gilbert; Ropelewski, Leszek; Sauli, Fabio; Sharma, A

1996-01-01

We describe operating priciples and results obtained with a new detector component: the Gas Electrons Multiplier (GEM). Consisting of a thin composite sheet with two metal layers separated by a thin insulator, and pierced by a regular matrix of open channels, the GEM electrode, inserted on the path of electrons in a gas detector, allows to transfer the charge with an amplification factor approaching ten. Uniform response and high rate capability are demonstrated. Coupled to another device, multiwire or micro-strip chamber, the GEM electrode permit to obtain higher gains or less critical operation; separation of the sensitive (conversion) volume and the detection volume has other advantages, as a built-in delay (useful for triggering purposes) and the possibility of applying high fields on the photo-cathode of ring imaging detectors to improve efficiency. Multiple GEM grids in the same gas volume allow to obtain large amplification factors in a succession of steps, leading to the realization of an effective ga...

First results of spherical GEMs

CERN Document Server

Pinto, Serge Duarte; Brock, Ian; Croci, Gabriele; David, Eric; de Oliveira, Rui; Ropelewski, Leszek; van Stenis, Miranda; Taureg, Hans; Villa, Marco

2010-01-01

We developed a method to make GEM foils with a spherical geometry. Tests of this procedure and with the resulting spherical GEMs are presented. Together with a spherical drift electrode, a spherical conversion gap can be formed. This eliminates the parallax error for detection of x-rays, neutrons or UV photons when a gaseous converter is used. This parallax error limits the spatial resolution at wide scattering angles. Besides spherical GEMs, we have developed curved spacers to maintain accurate spacing, and a conical field cage to prevent edge distortion of the radial drift field up to the limit of the angular acceptance of the detector. With these components first tests are done in a setup with a spherical entrance window but a planar readout structure; results will be presented and discussed. A flat readout structure poses difficulties, however. Therefore we will show advanced plans to make a prototype of an entirely spherical double-GEM detector, including a spherical 2D readout structure. This detector w...

A micro-TCA based data acquisition system for the Triple-GEM detectors for the upgrade of the CMS forward muon spectrometer

CERN Document Server

Lenzi, Thomas

2016-01-01

We will present the electronic and DAQ system being developed for TripleGEM detectors which will be installed in the CMS muon spectrometer. The microTCA system uses an Advanced Mezzanine Card equipped with an FPGA and the Versatile Link with the GBT chipset to link the front and back-end. On the detector an FPGA mezzanine board, the OptoHybrid, has to collect the data from the detector readout chips to transmit them optically to the microTCA boards using the GBT protocol. We will describe the hardware architecture, report on the status of the developments, and present results obtained with the system.In this contribution we will report on the progress of the design of the electronic readout and data acquisition (DAQ) system being developed for Triple-GEM detectors which will be installed in the forward region (1.5 < eta < 2.2) of the CMS muon spectrometer during the 2nd long shutdown of the LHC, planed for the period 2018-2019. The architecture of the Triple-GEM readout system is based on the use of the...

Recent Developments in GEM-Based Neutron Detectors

International Nuclear Information System (INIS)

Saenboonruang, K.

2014-01-01

The gas electron multiplier (GEM) detector is a relatively new gaseous detector that has been used for less than 20 years. Since the discovery in 1997 by F. Sauli, the GEM detector has shown excellent properties including high rate capability, excellent resolutions, low discharge probability, and excellent radiation hardness. These promising properties have led the GEM detector to gain popularity and attention amongst physicists and researchers. In particular, the GEM detector can also be modified to be used as a neutron detector by adding appropriate neutron converters. With properties stated above and the need to replace the expensive 3 He-based neutron detectors, the GEM-based neutron detector will be one of the most powerful and affordable neutron detectors. Applications of the GEM-based neutron detectors vary from researches in nuclear and particle physics, neutron imaging, and national security. Although several promising progresses and results have been shown and published in the past few years, further improvement is still needed in order to improve the low neutron detection efficiency (only a few percent) and to widen the possibilities for other uses.

Measurement of CP-violation with the GEM detector

International Nuclear Information System (INIS)

Yamamoto, Hiroaki

1993-01-01

In this note, the feasibility of measuring CP-violation in the B-meson system with the GEM detector at SSC is described, using the decay mode B d → J/ψ + K 0 S → μ + μ - π + π - for the β angle measurement. In Section 2, the signature of the signal is discussed. Section 3 is devoted to a description of the GEM performance, including the estimation of the backgrounds. The rate of the signal is discussed in Section 4, and the summary is given in Section 5

Analysis of current situation of information disclosure of listed companies on GEM

Directory of Open Access Journals (Sweden)

Zhirong Shen

2017-03-01

Full Text Available In the afternoon on October 23th, 2009, GEM was officially launched in our country. Due to the lack of experience in the market supervision, information disclosure violations frequently occurred. In April 2015, Shenzhen Stock Exchange puts forward morning information disclosure system to strengthen the reform of information disclosure system. Therefore, this paper deeply focuses on the current situation of information disclosure violations on GEM for the purpose of attracting more attention to the problems. Through studying the information disclosure violations of the listed companies on GEM from 2011 to September 30th, 2015, this paper divides the violations into the following four types: false record, misleading statement, material misstatement and delayed disclosure. On the other hand, we find that these types of violations are concurrent. From this discussion, we may safely draw the conclusion that the information disclosure of listed companies on GEM has the problem of untruthfulness, incorrectness, incompleteness and delay.

Development of the GEM-MACH-FireWork System: An Air Quality Model with On-line Wildfire Emissions within the Canadian Operational Air Quality Forecast System

Science.gov (United States)

Pavlovic, Radenko; Chen, Jack; Beaulieu, Paul-Andre; Anselmp, David; Gravel, Sylvie; Moran, Mike; Menard, Sylvain; Davignon, Didier

2014-05-01

A wildfire emissions processing system has been developed to incorporate near-real-time emissions from wildfires and large prescribed burns into Environment Canada's real-time GEM-MACH air quality (AQ) forecast system. Since the GEM-MACH forecast domain covers Canada and most of the U.S.A., including Alaska, fire location information is needed for both of these large countries. During AQ model runs, emissions from individual fire sources are injected into elevated model layers based on plume-rise calculations and then transport and chemistry calculations are performed. This "on the fly" approach to the insertion of the fire emissions provides flexibility and efficiency since on-line meteorology is used and computational overhead in emissions pre-processing is reduced. GEM-MACH-FireWork, an experimental wildfire version of GEM-MACH, was run in real-time mode for the summers of 2012 and 2013 in parallel with the normal operational version. 48-hour forecasts were generated every 12 hours (at 00 and 12 UTC). Noticeable improvements in the AQ forecasts for PM2.5 were seen in numerous regions where fire activity was high. Case studies evaluating model performance for specific regions and computed objective scores will be included in this presentation. Using the lessons learned from the last two summers, Environment Canada will continue to work towards the goal of incorporating near-real-time intermittent wildfire emissions into the operational air quality forecast system.

arXiv The new cylindrical GEM inner tracker of BESIII

CERN Document Server

Lavezzi, L.; Amoroso, A.; Ferroli, R. Baldini; Bertani, M.; Bettoni, D.; Bianchi, F.; Calcaterra, A.; Canale, N.; Capodiferro, M.; Carassiti, V.; Cerioni, S.; Chai, Jy; Chiozzi, S.; Cibinetto, G.; Cossio, F.; Cotta Ramusino, A.; De Mori, F.; Destefanis, M.; Dong, J.; Evangelisti, F.; Farinelli, R.; Fava, L.; Felici, G.; Fioravanti, E.; Garzia, I.; Gatta, M.; Greco, M.; Leng, Cy; Li, H.; Maggiora, M.; Malaguti, R.; Marcello, S.; Melchiorri, M.; Mezzadri, G.; Mignone, M.; Morello, G.; Pacetti, S.; Patteri, P.; Pellegrino, J.; Pelosi, A.; Rivetti, A.; Rolo,; Savrié, M.; Scodeggio, M.; Soldani, E.; Sosio, S.; Spataro, S.; Tskhadadze, E.; Verma, S.; Wheadon, R.; Yan, L.

2018-05-03

The Cylindrical GEM-Inner Tracker (CGEM-IT) is the upgrade of the internal tracking system of the BESIII experiment. It consists of three layers of cylindrically-shaped triple GEMs, with important innovations with respect to the existing GEM detectors, in order to achieve the best performance with the lowest material budget. It will be the first cylindrical GEM running with analog readout inside a 1T magnetic field. The simultaneous measurement of both the deposited charge and the signal time will permit to use a combination of two algorithms to evaluate the spatial position of the charged tracks inside the CGEM-IT: the charge centroid and the micro time projection chamber modes. They are complementary and can cope with the asymmetry of the electron avalanche when running in magnetic field and with non-orthogonal incident tracks. To evaluate the behaviour under different working settings, both planar chambers and the first cylindrical prototype have been tested during various test beams at CERN with 150 GeV/c...

GEM - The Global Earthquake Model

Science.gov (United States)

Smolka, A.

2009-04-01

Over 500,000 people died in the last decade due to earthquakes and tsunamis, mostly in the developing world, where the risk is increasing due to rapid population growth. In many seismic regions, no hazard and risk models exist, and even where models do exist, they are intelligible only by experts, or available only for commercial purposes. The Global Earthquake Model (GEM) answers the need for an openly accessible risk management tool. GEM is an internationally sanctioned public private partnership initiated by the Organisation for Economic Cooperation and Development (OECD) which will establish an authoritative standard for calculating and communicating earthquake hazard and risk, and will be designed to serve as the critical instrument to support decisions and actions that reduce earthquake losses worldwide. GEM will integrate developments on the forefront of scientific and engineering knowledge of earthquakes, at global, regional and local scale. The work is organized in three modules: hazard, risk, and socio-economic impact. The hazard module calculates probabilities of earthquake occurrence and resulting shaking at any given location. The risk module calculates fatalities, injuries, and damage based on expected shaking, building vulnerability, and the distribution of population and of exposed values and facilities. The socio-economic impact module delivers tools for making educated decisions to mitigate and manage risk. GEM will be a versatile online tool, with open source code and a map-based graphical interface. The underlying data will be open wherever possible, and its modular input and output will be adapted to multiple user groups: scientists and engineers, risk managers and decision makers in the public and private sectors, and the public-at- large. GEM will be the first global model for seismic risk assessment at a national and regional scale, and aims to achieve broad scientific participation and independence. Its development will occur in a

A micro-TCA based data acquisition system for the Triple-GEM detectors for the upgrade of the CMS forward muon spectrometer

Science.gov (United States)

Lenzi, T.

2017-01-01

The Gas Electron Multiplier (GEM) upgrade project aims at improving the performance of the muon spectrometer of the Compact Muon Solenoid (CMS) experiment which will suffer from the increase in luminosity of the Large Hadron Collider (LHC). The GEM collaboration proposes to instrument the first muon station with Triple-GEM detectors, a technology which has proven to be resistant to high fluxes of particles. The architecture of the readout system is based on the use of the microTCA standard hosting FPGA-based Advanced Mezzanine Card (AMC) and of the Versatile Link with the GBT chipset to link the on-detector electronics to the micro-TCA boards. For the front-end electronics a new ASIC, called VFAT3, is being developed. On the detector, a Xilinx Virtex-6 FPGA mezzanine board, called the OptoHybrid, has to collect the data from 24 VFAT3s and to transmit the data optically to the off-detector micro-TCA electronics, as well as to transmit the trigger data at 40 MHz to the CMS Cathode Strip Chamber (CSC) trigger. The microTCA electronics provides the interfaces from the detector (and front-end electronics) to the CMS DAQ, TTC (Timing, Trigger and Control) and Trigger systems. In this paper, we will describe the DAQ system of the Triple-GEM project and provide results from the latest test beam campaigns done at CERN.

Extending the ISC-GEM Global Earthquake Instrumental Catalogue

Science.gov (United States)

Di Giacomo, Domenico; Engdhal, Bob; Storchak, Dmitry; Villaseñor, Antonio; Harris, James

2015-04-01

After a 27-month project funded by the GEM Foundation (www.globalquakemodel.org), in January 2013 we released the ISC-GEM Global Instrumental Earthquake Catalogue (1900 2009) (www.isc.ac.uk/iscgem/index.php) as a special product to use for seismic hazard studies. The new catalogue was necessary as improved seismic hazard studies necessitate that earthquake catalogues are homogeneous (to the largest extent possible) over time in their fundamental parameters, such as location and magnitude. Due to time and resource limitation, the ISC-GEM catalogue (1900-2009) included earthquakes selected according to the following time-variable cut-off magnitudes: Ms=7.5 for earthquakes occurring before 1918; Ms=6.25 between 1918 and 1963; and Ms=5.5 from 1964 onwards. Because of the importance of having a reliable seismic input for seismic hazard studies, funding from GEM and two commercial companies in the US and UK allowed us to start working on the extension of the ISC-GEM catalogue both for earthquakes that occurred beyond 2009 and for earthquakes listed in the International Seismological Summary (ISS) which fell below the cut-off magnitude of 6.25. This extension is part of a four-year program that aims at including in the ISC-GEM catalogue large global earthquakes that occurred before the beginning of the ISC Bulletin in 1964. In this contribution we present the updated ISC GEM catalogue, which will include over 1000 more earthquakes that occurred in 2010 2011 and several hundreds more between 1950 and 1959. The catalogue extension between 1935 and 1949 is currently underway. The extension of the ISC-GEM catalogue will also be helpful for regional cross border seismic hazard studies as the ISC-GEM catalogue should be used as basis for cross-checking the consistency in location and magnitude of those earthquakes listed both in the ISC GEM global catalogue and regional catalogues.

Ion feedback effect in the multi GEM structure

International Nuclear Information System (INIS)

Park, Se Hwan; Kim, Yong Kyun; Han, Sang Hyo; Ha, Jang Ho; Moon, Byung Soo; Chung, Chong Eun

2003-01-01

The feedback of positive ions in a gas electron multiplier (GEM) has to be suppressed to reduce the photocathode degradation in GEM photomultipliers and to prevent the field distortion in a time projection chamber (TPC). The ion feedback dependency on the drift electric field, the transfer field, the asymmetry in the voltages across the GEM, and the effective gain was carefully measured in various gases. The ion feedback is sensitive to the drift field and the effective gain. A model prediction of the ion feedback in a double GEM structure was compared with the measurement. Our systematic study of the ion feedback effect can lead to progress in gas detectors with GEMs.

GEM1: First-year modeling and IT activities for the Global Earthquake Model

Science.gov (United States)

Anderson, G.; Giardini, D.; Wiemer, S.

2009-04-01

GEM is a public-private partnership initiated by the Organisation for Economic Cooperation and Development (OECD) to build an independent standard for modeling and communicating earthquake risk worldwide. GEM is aimed at providing authoritative, open information about seismic risk and decision tools to support mitigation. GEM will also raise risk awareness and help post-disaster economic development, with the ultimate goal of reducing the toll of future earthquakes. GEM will provide a unified set of seismic hazard, risk, and loss modeling tools based on a common global IT infrastructure and consensus standards. These tools, systems, and standards will be developed in partnership with organizations around the world, with coordination by the GEM Secretariat and its Secretary General. GEM partners will develop a variety of global components, including a unified earthquake catalog, fault database, and ground motion prediction equations. To ensure broad representation and community acceptance, GEM will include local knowledge in all modeling activities, incorporate existing detailed models where possible, and independently test all resulting tools and models. When completed in five years, GEM will have a versatile, penly accessible modeling environment that can be updated as necessary, and will provide the global standard for seismic hazard, risk, and loss models to government ministers, scientists and engineers, financial institutions, and the public worldwide. GEM is now underway with key support provided by private sponsors (Munich Reinsurance Company, Zurich Financial Services, AIR Worldwide Corporation, and Willis Group Holdings); countries including Belgium, Germany, Italy, Singapore, Switzerland, and Turkey; and groups such as the European Commission. The GEM Secretariat has been selected by the OECD and will be hosted at the Eucentre at the University of Pavia in Italy; the Secretariat is now formalizing the creation of the GEM Foundation. Some of GEM's global

Study of etching processes in the GEM detectors

CERN Document Server

Zavazieva, Darina

2016-01-01

Gaseous Electron Multiplier (GEM) detectors are known to operate stably at high gains and high particle fluxes. Though, at very high gains and fluxes it was observed that the insulating polyimide layer between the GEM electrodes gets etched, changing the original shape of the hole, and therefore varying the gain and the energy resolution of the detector. The idea of the project to observe degradation effect of the GEM foils during the Triple GEM detector operation in extreme conditions under X-ray radiation.

Data Integration for Spatio-Temporal Patterns of Gene Expression of Zebrafish development: the GEMS database

Directory of Open Access Journals (Sweden)

Belmamoune Mounia

2008-06-01

Full Text Available The Gene Expression Management System (GEMS is a database system for patterns of gene expression. These patterns result from systematic whole-mount fluorescent in situ hybridization studies on zebrafish embryos. GEMS is an integrative platform that addresses one of the important challenges of developmental biology: how to integrate genetic data that underpin morphological changes during embryogenesis. Our motivation to build this system was by the need to be able to organize and compare multiple patterns of gene expression at tissue level. Integration with other developmental and biomolecular databases will further support our understanding of development. The GEMS operates in concert with a database containing a digital atlas of zebrafish embryo; this digital atlas of zebrafish development has been conceived prior to the expansion of the GEMS. The atlas contains 3D volume models of canonical stages of zebrafish development in which in each volume model element is annotated with an anatomical term. These terms are extracted from a formal anatomical ontology, i.e. the Developmental Anatomy Ontology of Zebrafish (DAOZ. In the GEMS, anatomical terms from this ontology together with terms from the Gene Ontology (GO are also used to annotate patterns of gene expression and in this manner providing mechanisms for integration and retrieval . The annotations are the glue for integration of patterns of gene expression in GEMS as well as in other biomolecular databases. At the one hand, zebrafish anatomy terminology allows gene expression data within GEMS to be integrated with phenotypical data in the 3D atlas of zebrafish development. At the other hand, GO terms extend GEMS expression patterns integration to a wide range of bioinformatics resources.

Experimental and Theoretical Progress on the GEM Theory

Science.gov (United States)

Brandenburg, J. E.

This paper reports experimental and theoretical progress on the GEM unification theory. In theoretical progress, the derivation of the GEM theory using it in a fully covariant form is achieved based on the principle of self-cancellation of the ZPF EM stress-momentum tensor. This derivation reveals that the final Gravity-EM system obeys a Helmholtz-like equation resembling that governing sound propagation. Finally an improved derivation of the formula for the Newton Gravitation constant is shown, qresulting in the formula G = e2/(4πɛ0 me mp) α exp (-2 (α-.86/σ2…) = 6.673443 x10-11 N-m2 kg-2 that agrees with experimental values to 3 parts per 100,000. Experiments have found parity violating weight reductions in gyroscopes driven by rotating EM fields. These experiments appear to confirm gravity modification using electromagnetism predicted by the GEM theory through the Vacuum Bernoulli Equation.

A GEM of an SSC detector

International Nuclear Information System (INIS)

Anon.

1992-01-01

The SSC Laboratory has decided to support the GEM (Gammas, Electrons, and Muons) detector collaboration in the next stage of its work, development of a Technical Design Report. Initial ideas for GEM as the second major SSC detector were aired last year

The cylindrical GEM detector of the KLOE-2 experiment

International Nuclear Information System (INIS)

Bencivenni, G.; Ciambrone, P.; De Lucia, E.; Domenici, D.; Felici, G.; Fermani, P.; Morello, G.; Branchini, P.; Cicco, A. Di; Czerwinski, E.

2017-01-01

The KLOE-2 experiment started its data taking campaign in November 2014 with an upgraded tracking system at the DAΦNE electron-positron collider at the Frascati National Laboratory of INFN. The new tracking device, the Inner Tracker, operated together with the KLOE-2 Drift Chamber, has been installed to improve track and vertex reconstruction capabilities of the experimental apparatus. The Inner Tracker is a cylindrical GEM detector composed of four cylindrical triple-GEM detectors, each provided with an X-V strips-pads stereo readout. Although GEM detectors are already used in high energy physics experiments, this device is considered a frontier detector due to its fully-cylindrical geometry: KLOE-2 is the first experiment benefiting of this novel detector technology. Alignment and calibration of this detector will be presented together with its operating performance and reconstruction capabilities.

CMS GEM detector material study for the HL-LHC

CERN Document Server

Muhammad, Saleh

2017-01-01

A study on the Gaseous Electron Multiplier (GEM) foil material is performed to determine the moisture diffusion rate and saturation level and the moisture effects on its mechanical properties. The study is focused on the foil contact with ambient air and moisture to determine the value of the diffusion coefficient of water in the detector polyimide. The presence of water inside the detector foil can determine the changes in its mechanical and electrical properties. A simulated model is developed by taking into account the real GEM foil (hole dimensions, shapes and material), which describes the adsorption on a sample. This work describes the model, its experimental verification, the water diffusion within the entire sheet geometry of the GEM foil, thus gaining concentration profiles and the time required to saturate the system and the effects on the mechanical properties.

A 32-channel front-end ASIC for GEM detectors used in beam monitoring applications

Science.gov (United States)

Ciciriello, F.; Altieri, P. R.; Corsi, F.; De Robertis, G.; Felici, G.; Loddo, F.; Lorusso, L.; Marzocca, C.; Matarrese, G.; Ranieri, A.; Stamerra, A.

2017-11-01

A multichannel, mixed-signal, front-end ASIC for GEM detectors, intended for beam monitoring in hadron therapy applications, has been designed and prototyped in a standard 0.35 μm CMOS technology. The analog channels are based on the classic CSA + shaper processing chain, followed by a peak detector which can work as an analog memory, to simplifiy the analog-to-digital conversion of the peak voltage of the output pulse, proportional to the energy of the detected event. The available hardware resources include an 8-bit A/D converter and a standard-cell digital part, which manages the read-out procedure, in sparse or serial mode. The ASIC is self-triggered and transfers energy and address data to the external DAQ via a fast 100 MHz LVDS link. Preliminary characterization results show that the non-linearity error is limited to 5% for a maximum input charge of about 70 fC, the measured ENC is about 1400e- and the time jitter of the trigger signal generated in response to an injected charge of 60 fC is close to 200 ps.

Performance Evaluation of the COBRA GEM for the Application of the TPC

Science.gov (United States)

Terasaki, Kohei; Hamagaki, Hideki; Gunji, Taku; Yamaguchi, Yorito

2014-09-01

Suppression of the back-drifting ions from avalanche region to drift space (IBF: Ion Backflow) is the key for a Time Projection Chamber (TPC) since IBF easily distorts the drift field. To suppress IBF, Gating Grid system is widely used for the TPC but this limits the data taking rate. Gas Electron Multiplier (GEM) has advantages in the reduction of IBF and high rate capability. By adopting GEM, it is possible to run a TPC continuously under high rate and high multiplicity conditions. Motivated by the study of IBF reduction for RICH with Thick COBRA, which has been developed by F. A. Amero et al., we developed COBRA GEMs for the application of a TPC. With a stack configuration, IBF reaches about 0.1 ~ 0.5%, which is ×5--10 better IBF than the standard GEMs. However, the measured energy resolution with COBRA is 20% (σ) and this is much worse than the resolution with standard GEMs. Measurement of long-time stability of gain indicates that gain of COBRA varies significantly due to charging up effect. Simulation studies based on Garfield++ are performed for understanding quantitatively the reasons of worse energy resolution and instability of gain. In this presentation, we will report the simulation studies together with the measured performance of the COBRA GEM.

Modeling of serial data acquisition structure for GEM detector system in Matlab

Science.gov (United States)

Kolasinski, Piotr; Pozniak, Krzysztof T.; Czarski, Tomasz; Chernyshova, Maryna; Kasprowicz, Grzegorz; Krawczyk, Rafal D.; Wojenski, Andrzej; Zabolotny, Wojciech; Byszuk, Adrian

2016-09-01

This article presents method of modeling in Matlab hardware architecture dedicated for FPGA created by languages like VHDL or Verilog. Purposes of creating such type of model with its advantages and disadvantages are described. Rules presented in this article were exploited to create model of Serial Data Acquisition algorithm used in X-ray GEM detector system. Result were compared to real working model implemented in VHDL. After testing of basic structure, other two structures were modeled to see influence parameters of the structure on its behavior.

Promoting microbiology education through the iGEM synthetic biology competition.

Science.gov (United States)

Kelwick, Richard; Bowater, Laura; Yeoman, Kay H; Bowater, Richard P

2015-08-01

Synthetic biology has developed rapidly in the 21st century. It covers a range of scientific disciplines that incorporate principles from engineering to take advantage of and improve biological systems, often applied to specific problems. Methods important in this subject area include the systematic design and testing of biological systems and, here, we describe how synthetic biology projects frequently develop microbiology skills and education. Synthetic biology research has huge potential in biotechnology and medicine, which brings important ethical and moral issues to address, offering learning opportunities about the wider impact of microbiological research. Synthetic biology projects have developed into wide-ranging training and educational experiences through iGEM, the International Genetically Engineered Machines competition. Elements of the competition are judged against specific criteria and teams can win medals and prizes across several categories. Collaboration is an important element of iGEM, and all DNA constructs synthesized by iGEM teams are made available to all researchers through the Registry for Standard Biological Parts. An overview of microbiological developments in the iGEM competition is provided. This review is targeted at educators that focus on microbiology and synthetic biology, but will also be of value to undergraduate and postgraduate students with an interest in this exciting subject area. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Progress in GEM-based gaseous photomultipliers

CERN Document Server

Chechik, R; Breskin, Amos; Buzulutskov, A F; Guedes, G P; Mörmann, D; Singh, B K

2003-01-01

We discuss recent progress in gaseous photomultipliers (GPMTs) comprising UV-to-visible spectral range photocathodes (PCs) coupled to multiple Gas Electron Multipliers (GEM). The PCs may be either semitransparent or reflective ones directly deposited on the first-GEM surface. These detectors provide high gain, even in noble gases, are sensitive to single photons, have nanosecond time resolution, and offer good localization. The operation of CsI-based GPMTs in CF sub 4 opens new applications in Cherenkov detectors, where both the radiator and the photosensor operate in the same gas. The latest results on sealed visible-light detectors, combining bialkali PCs and Kapton-made GEMs are presented.

Test and improvement of readout system based on APV25 chip for GEM detector

International Nuclear Information System (INIS)

Hu Shouyang; Jian Siyu; Zhou Jing; Shan Chao; Li Xinglong; Li Xia; Li Xiaomei; Zhou Yi

2014-01-01

Gas electron multiplier (GEM) is the most promising position sensitive gas detector. The new generation of readout electronics system includes APV25 front-end card, multi-purpose digitizer (MPD), VME controller and Linux-based acquisition software DAQ. The construction and preliminary test of this readout system were finished, and the ideal data with the system working frequency of 40 MHz and 20 MHz were obtained. The long time running test shows that the system has a very good time-stable ability. Through optimizing the software configuration and improving hardware quality, the noise level was reduced, and the signal noise ratio was improved. (authors)

Gravity model improvement using GEOS-3 (GEM 9 and 10)

Science.gov (United States)

Lerch, F. J.; Klosko, S. M.; Laubscher, R. E.; Wagner, C. A.

1977-01-01

The use of collocation permitted GEM 9 to be a larger field than previous derived satellite models, GEM 9 having harmonics complete to 20 x 20 with selected higher degree terms. The satellite data set has approximately 840,000 observations, of which 200,000 are laser ranges taken on 9 satellites equipped with retroreflectors. GEM 10 is complete to 22 x 22 with selected higher degree terms out to degree and order 30 amounting to a total of 592 coefficients. Comparisons with surface gravity and altimeter data indicate a substantial improvement in GEM 9 over previous satellite solutions; GEM 9 is in even closer agreement with surface data than the previously published GEM 6 solution which contained surface gravity. In particular the free air gravity anomalies calculated from GEM 9 and a surface gravity solution are in excellent agreement for the high degree terms.

ROLE OF GEMS IN INDIAN MEDICINE

Science.gov (United States)

Murthy, S.R.N.

1991-01-01

This paper is the first attempt in introducing the medicinal importance of gems as found in the Sanskrit text ‘Rasaratnasamuccaya’, which has been rendered an English translation here. The modern physicians and gemologists will find this study quite useful in continuing research and, thus, develop a new field of gem medicine. PMID:22556526

3D simulation of electron and ion transmission of GEM-based detectors

Science.gov (United States)

Bhattacharya, Purba; Mohanty, Bedangadas; Mukhopadhyay, Supratik; Majumdar, Nayana; da Luz, Hugo Natal

2017-10-01

Time Projection Chamber (TPC) has been chosen as the main tracking system in several high-flux and high repetition rate experiments. These include on-going experiments such as ALICE and future experiments such as PANDA at FAIR and ILC. Different R&D activities were carried out on the adoption of Gas Electron Multiplier (GEM) as the gas amplification stage of the ALICE-TPC upgrade version. The requirement of low ion feedback has been established through these activities. Low ion feedback minimizes distortions due to space charge and maintains the necessary values of detector gain and energy resolution. In the present work, Garfield simulation framework has been used to study the related physical processes occurring within single, triple and quadruple GEM detectors. Ion backflow and electron transmission of quadruple GEMs, made up of foils with different hole pitch under different electromagnetic field configurations (the projected solutions for the ALICE TPC) have been studied. Finally a new triple GEM detector configuration with low ion backflow fraction and good electron transmission properties has been proposed as a simpler GEM-based alternative suitable for TPCs for future collider experiments.

The HadGEM2 family of Met Office Unified Model climate configurations

Directory of Open Access Journals (Sweden)

The HadGEM2 Development Team: G. M. Martin

2011-09-01

Full Text Available We describe the HadGEM2 family of climate configurations of the Met Office Unified Model, MetUM. The concept of a model "family" comprises a range of specific model configurations incorporating different levels of complexity but with a common physical framework. The HadGEM2 family of configurations includes atmosphere and ocean components, with and without a vertical extension to include a well-resolved stratosphere, and an Earth-System (ES component which includes dynamic vegetation, ocean biology and atmospheric chemistry. The HadGEM2 physical model includes improvements designed to address specific systematic errors encountered in the previous climate configuration, HadGEM1, namely Northern Hemisphere continental temperature biases and tropical sea surface temperature biases and poor variability. Targeting these biases was crucial in order that the ES configuration could represent important biogeochemical climate feedbacks. Detailed descriptions and evaluations of particular HadGEM2 family members are included in a number of other publications, and the discussion here is limited to a summary of the overall performance using a set of model metrics which compare the way in which the various configurations simulate present-day climate and its variability.

A free-volume modification of GEM-QC to correlate VLE and LLE in polymer solutions

International Nuclear Information System (INIS)

Radfarnia, H.R.; Taghikhani, V.; Ghotbi, C.; Khoshkbarchi, M.K.

2004-01-01

The generalized quasi-chemical (GEM-QC) model proposed by Wang and Vera is modified to correlate better the phase equilibrium and to overcome the shortcoming of the original model to predict the lower critical solution temperature (LCST) of binary polymer solutions. This shortcoming is mainly because the GEM-QC model does not consider the effect of free-volume, which is important in systems containing molecules with large size differences. The proposed modification is based on replacing the combinatorial term of the GEM-QC model by a term proposed by Kontogerogis et al., which includes the effect of the free-volume. The main advantage of the free volume generalized quasi-chemical (GEM-QC-FV) model over the original GEM-QC is its ability to predict the phase behaviour of binary polymer solutions with LCST behaviour. In addition, the free volume UNIQUAC (UNIQUAC-FV) model is used to correlate VLE and LLE experimental data for binary polymer solutions. The comparison of the results obtained from the GEM-QC-FV model and the UNIQUAC-FV model shows the superiority of the GEM-QC-FV model in correlating the VLE and LLE experimental data for binary polymer solutions

Development of the data acquisition system for the Triple-GEM detectors for the upgrade of the CMS forward muon spectrometer

CERN Document Server

Abbaneo, D; Akl, M A; Ahmed, W; Armaingaud, C; Aspell, P; Assran, Y; Bally, S; Ban, Y; Banerjee, S; Barria, P; Benussi, L; Bhopatkar, V; Bianco, S; Bos, J; Bouhali, O; Cai, J; Calabria, C; Castaneda, A; Cauwenbergh, S; Celik, A; Christiansen, J; Colafranceschi, S; Colaleo, A; Conde Garcia, A; Dabrowski, M; De Lentdecker, G; De Oliveira, R; De Robertis, G; Dildick, S; Ferry, S; Flanagan, W; Gilmore, J; Guilloux, F; Gutierrez, A; Hoepfner, K; Hohlmann, M; Kamon, T; Karchin, P E; Khotilovich, V; Korntheuer, M; Krutelyov, S; Lenzi, T; Loddo, F; Maerschalk, T; Magazzu, G; Maggi, M; Maghrbi, Y; Marchioro, A; Marinov, A; Mazumdar, N; Merlin, J A; Mukhopadhyay, S; Nuzzo, S; Oliveri, E; Philipps, B; Piccolo, D; Postema, H; Radi, A; Radogna, R; Raffone, G; Ranieri, A; Rodrigues, A; Ropelewski, L; Safonov, A; Sakharov, A; Salva, S; Saviano, G; Sharma, A; Talvitie, J; Tatarinov, A; Teng, H; Turini, N; Tuuva, T; Twigger, J; Tytgat, M; van Stenis, M.; Verhagen, E; Yang, Y; Zaganidis, N; Zenoni, F

2014-01-01

In this contribution we will report on the progress of thedesign of the readout and data acquisition system being developedfor triple-GEM detectors which will be installed in the forwardregion (1.5 < |η| < 2.2) of the CMS muonspectrometer during the 2nd long shutdown of the LHC, expectedin the period 2017–2018. The system will be designed to take fulladvantage of current generic developments introduced for the LHCupgrades. The current design is based on the use of CERN GLIB boardshosted in micro-TCA crates for the off-detector electronics and theVersatile Link with the GBT chipset to link the front-endelectronics to the GLIB boards. In this contribution we willdescribe the physics goals, the hardware architectures and report onthe expected performance of the CMS GEM readout system, includingpreliminary timing resolution simulations.

Preliminary results of the Gas Electron Multiplier (GEM) as real-time beam monitor in hadron therapy

Energy Technology Data Exchange (ETDEWEB)

Aza, E., E-mail: eleni.aza@cern.ch [CERN, Geneva 23, 1211 Geneva (Switzerland); AUTH, Department of Physics, 54124 Thessaloniki (Greece); Ciocca, M. [Fondazione CNAO, Strada Campeggi 53, 27100 Pavia (Italy); Murtas, F. [CERN, Geneva 23, 1211 Geneva (Switzerland); LNF-INFN, Via Fermi 40, 00044 Frascati (Italy); Puddu, S. [CERN, Geneva 23, 1211 Geneva (Switzerland); AEC-LHEP, University of Bern, Sidlerstrasse 5, 3012 Bern (Switzerland); Pullia, M. [Fondazione CNAO, Strada Campeggi 53, 27100 Pavia (Italy); Silari, M. [CERN, Geneva 23, 1211 Geneva (Switzerland)

2017-01-01

The use of proton and carbon ion beams in cancer therapy (also known as hadron therapy) is progressively growing worldwide due to their improved dose distributions, sparing of healthy tissues and (for carbon ions) increased radiobiological effectiveness especially for radio-resistant tumours. Strict Quality Assurance (QA) protocols need to be followed for guaranteeing the clinical beam specifications. The aim of this study was to assess the performance of a gaseous detector based on the Gas Electron Multiplier (GEM) technology for measuring the beam spot dimensions and the homogeneity of the scanned irradiation field, which are daily QA tasks commonly performed using radiochromic films. Measurements performed at the National Centre for Oncological Hadron Therapy (CNAO) in Pavia (Italy) showed that the detector is able to monitor the 2D beam image on-line with a pad granularity of 2 mm and a response proportional to the number of delivered particles. The dose homogeneity was measured with low deviation from the results obtained with radiochromic films.

Design of data acquisition system for GEM detector

International Nuclear Information System (INIS)

Lu Jianliang; Chen Ziyu; Shen Ji; Jin Xi

2011-01-01

It describes the design and realization of the USB 2.0 high speed data acquisition devise which is used in the readout electronics of the GEM (gas electron multiplier) detector. By using of the USB Microcontroller EZ-USB FX2 CY7C68013A, high speed ADC and FPGA, high-speed data rate of data acquisition and transmission was realized. The data rate reaches to 20 MByte/s, meeting the requirements of data acquisition and transmission of the detector. (authors)

New Approach for 2D Readout of GEM Detectors

International Nuclear Information System (INIS)

Hasell, Douglas K.

2011-01-01

Detectors based on Gas Electron Multiplication (GEM) technology are becoming more and more widely used in nuclear and high energy physics and are being applied in astronomy, medical physics, industry, and homeland security. GEM detectors are thin, low mass, insensitive to magnetic fields, and can currently provide position resolutions down to ∼50 microns. However, the designs for reconstructing the position, in two dimensions (2D), of the charged particles striking a GEM detector are often complicated to fabricate and expensive. The objective of this proposal is to investigate a simpler procedure for producing the two dimensional readout layer of GEM detectors using readily available printed circuit board technology which can be tailored to the detector requirements. We will use the established GEM laboratory and facilities at M.I.T. currently employed in developing GEM detectors for the STAR forward tracking upgrade to simplify the testing and evaluation of the new 2D readout designs. If this new design proves successful it will benefit future nuclear and high energy physics experiments already being planned and will similarly extend and simplify the application of GEM technology to other branches of science, medicine, and industry. These benefits would be not only in lower costs for fabrication but also it increased flexibility for design and application.

Analysis of activation yields by INC/GEM

International Nuclear Information System (INIS)

Furihata, Shiori; Nakashima, Hiroshi

2001-01-01

Excitation functions of the nuclides produced from the reaction on nitrogen and oxygen target irradiated by nucleons are analyzed using INC/GEM. It is shown that INC/GEM reproduces most of the cross sections within a factor of two to three. (author)

GEM-loaded magnetic albumin nanospheres modified with cetuximab for simultaneous targeting, magnetic resonance imaging, and double-targeted thermochemotherapy of pancreatic cancer cells.

Science.gov (United States)

Wang, Ling; An, Yanli; Yuan, Chenyan; Zhang, Hao; Liang, Chen; Ding, Fengan; Gao, Qi; Zhang, Dongsheng

2015-01-01

Targeted delivery is a promising strategy to improve the diagnostic imaging and therapeutic effect of cancers. In this paper, novel cetuximab (C225)-conjugated, gemcitabine (GEM)-containing magnetic albumin nanospheres (C225-GEM/MANs) were fabricated and applied as a theranostic nanocarrier to conduct simultaneous targeting, magnetic resonance imaging (MRI), and double-targeted thermochemotherapy against pancreatic cancer cells. Fe3O4 nanoparticles (NPs) and GEM co-loaded albumin nanospheres (GEM/MANs) were prepared, and then C225 was further conjugated to synthesize C225-GEM/MANs. Their morphology, mean particle size, GEM encapsulation ratio, specific cell-binding ability, and thermal dynamic profiles were characterized. The effects of discriminating different EGFR-expressing pancreatic cancer cells (AsPC-1 and MIA PaCa-2) and monitoring cellular targeting effects were assessed by targeted MRI. Lastly, the antitumor efficiency of double/C225/magnetic-targeted and nontargeted thermochemotherapy was compared with chemotherapy alone using 3-(4, 5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and flow cytometry (FCM) assay. When treated with targeted nanospheres, AsPC-1 cells showed a significantly less intense MRI T2 signal than MIA PaCa-2 cells, while both cells had similar signal strength when incubated with nontargeted nanospheres. T2 signal intensity was significantly lower when magnetic and C225 targeting were combined, rather than used alone. The inhibitory and apoptotic rates of each thermochemotherapy group were significantly higher than those of the chemotherapy-alone groups. Additionally, both MTT and FCM analysis verified that double-targeted thermochemotherapy had the highest targeted killing efficiency among all groups. The C225-GEM/MANs can distinguish various EGFR-expressing live pancreatic cancer cells, monitor diverse cellular targeting effects using targeted MRI imaging, and efficiently mediate double-targeted thermochemotherapy

Reduction experiment of FeO-bearing amorphous silicate: application to origin of metallic iron in GEMS

Energy Technology Data Exchange (ETDEWEB)

Matsuno, Junya; Tsuchiyama, Akira; Miyake, Akira [Department of Geology and Mineralogy, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502 (Japan); Noguchi, Ryo [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Ichikawa, Satoshi, E-mail: jmatsuno@kueps.kyoto-u.ac.jp [Institute for Nano-science Design, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

2014-09-10

Glass with embedded metal and sulfides (GEMS) are amorphous silicates included in anhydrous interplanetary dust particles (IDPs) and can provide information about material evolution in our early solar system. Several formation processes for GEMS have been proposed so far, but these theories are still being debated. To investigate a possible GEMS origin by reduction of interstellar silicates, we synthesized amorphous silicates with a mean GEMS composition and performed heating experiments in a reducing atmosphere. FeO-bearing amorphous silicates were heated at 923 K and 973 K for 3 hr, and at 1023 K for 1-48 hr at ambient pressure in a reducing atmosphere. Fe grains formed at the interface between the silicate and the reducing gas through a reduction. In contrast, TEM observations of natural GEMS show that metallic grains are uniformly embedded in amorphous silicates. Therefore, the present study suggests that metallic inclusions in GEMS could not form as reduction products and that other formation process such as condensation or irradiation are more likely.

ARTROC—a readout ASIC for GEM-based full-field XRF imaging system

Science.gov (United States)

Fiutowski, T.; Koperny, S.; Łach, B.; Mindur, B.; Świentek, K.; Wiącek, P.; Dąbrowski, W.

2017-12-01

In the paper we report on development of an Application Specific Integrated Circuit (ASIC), called ARTROC, being part of a full-field X-ray fluorescence spectroscopy (XRF) imaging system equipped with a standard three stage Gas Electron Multiplier (GEM) detector of 10×10 cm2 area. The ARTROC consists of 64 independent channels, allowing for simultaneous recording of the amplitudes (energy sub-channel) and time stamps (timing sub-channel) of incoming signals. Thanks to the implemented token-based read out of derandomizing buffers, the ASIC also provides data sparsification and full zero suppression. Reconstruction of the hit positions is performed in an external data acquisition system by matching the time stamps of signals recorded in X- and Y-strips. The amplitude information is used for centre of gravity finding in clusters of signals on neighbouring strips belonging to the same detection events. The ASIC could work in one of six gain modes and one of two speed modes. In a slower mode the maximum count rate per channel is 105/s while in a faster mode it is three times higher. The ARTROC comprises also input protection circuits against possible random discharges inside active detector volume, so it can be used without any additional input components. The ASIC has been designed in 350 nm CMOS process. The basic functionality and parameters have been evaluated using the testability functions implemented in the ASIC design. The ASIC has been also tested in a fully equipped GEM detector set-up with X-rays source.

The determination of the orbit of the Japanese satellite Ajisai and the GEM-T1 and GEM-T2 gravity field models

Science.gov (United States)

Sanchez, Braulio V.

1990-01-01

The Japanese Experimental Geodetic Satellite Ajisai was launched on August 12, 1986. In response to the TOPEX-POSEIDON mission requirements, the GSFC Space Geodesy Branch and its associates are producing improved models of the Earth's gravitational field. With the launch of Ajisai, precise laser data is now available which can be used to test many current gravity models. The testing of the various gravity field models show improvements of more than 70 percent in the orbital fits when using GEM-T1 and GEM-T2 relative to results obtained with the earlier GEM-10B model. The GEM-T2 orbital fits are at the 13-cm level (RMS). The results of the tests with the various versions of the GEM-T1 model indicate that the addition of satellite altimetry and surface gravity anomalies as additional data types should improve future gravity field models.

Radiation imaging with optically read out GEM-based detectors

Science.gov (United States)

Brunbauer, F. M.; Lupberger, M.; Oliveri, E.; Resnati, F.; Ropelewski, L.; Streli, C.; Thuiner, P.; van Stenis, M.

2018-02-01

Modern imaging sensors allow for high granularity optical readout of radiation detectors such as MicroPattern Gaseous Detectors (MPGDs). Taking advantage of the high signal amplification factors achievable by MPGD technologies such as Gaseous Electron Multipliers (GEMs), highly sensitive detectors can be realised and employing gas mixtures with strong scintillation yield in the visible wavelength regime, optical readout of such detectors can provide high-resolution event representations. Applications from X-ray imaging to fluoroscopy and tomography profit from the good spatial resolution of optical readout and the possibility to obtain images without the need for extensive reconstruction. Sensitivity to low-energy X-rays and energy resolution permit energy resolved imaging and material distinction in X-ray fluorescence measurements. Additionally, the low material budget of gaseous detectors and the possibility to couple scintillation light to imaging sensors via fibres or mirrors makes optically read out GEMs an ideal candidate for beam monitoring detectors in high energy physics as well as radiotherapy. We present applications and achievements of optically read out GEM-based detectors including high spatial resolution imaging and X-ray fluorescence measurements as an alternative readout approach for MPGDs. A detector concept for low intensity applications such as X-ray crystallography, which maximises detection efficiency with a thick conversion region but mitigates parallax-induced broadening is presented and beam monitoring capabilities of optical readout are explored. Augmenting high resolution 2D projections of particle tracks obtained with optical readout with timing information from fast photon detectors or transparent anodes for charge readout, 3D reconstruction of particle trajectories can be performed and permits the realisation of optically read out time projection chambers. Combining readily available high performance imaging sensors with compatible

Gas electron multiplier (GEM) foil test, repair and effective gain calculation

Science.gov (United States)

Tahir, Muhammad; Zubair, Muhammad; Khan, Tufail A.; Khan, Ashfaq; Malook, Asad

2018-06-01

The focus of my research is based on the gas electron multiplier (GEM) foil test, repairing and effective gain calculation of GEM detector. During my research work define procedure of GEM foil testing short-circuit, detection short-circuits in the foil. Study different ways to remove the short circuits in the foils. Set and define the GEM foil testing procedures in the open air, and with nitrogen gas. Measure the leakage current of the foil and applying different voltages with specified step size. Define the Quality Control (QC) tests and different components of GEM detectors before assembly. Calculate the effective gain of GEM detectors using 109Cd and 55Fe radioactive source.

The Shape of Long Outbursts in U Gem Type Dwarf Novae from AAVSO Data

Science.gov (United States)

Cannizzo, John K.

2012-01-01

We search the American Association of Variable Star Observers (AAVSO) archives of the two best studied dwarf novae in an attempt to find light curves for long out bursts that are extremely well-characterized. The systems are U Gem and S8 Cyg. Our goal is to search for embedded precursors such as those that have been found recently in the high fidelity Kepler data for superoutbursts of some members of the 8U UMa subclass of dwarf novae. For the vast majority of AAV80 data, the combination of low data cadence and large errors associated with individual measurements precludes one from making any strong statement about the shape of the long outbursts. However, for a small number of outbursts, extensive long term monitoring with digital photometry yields high fidelity light curves. We report the finding of embedded precursors in two of three candidate long outbursts. This reinforces van Paradijs' finding that long outbursts in dwarf novae above the period gap and superoutbursts in systems below the period gap constitute a unified class. The thermal-tidal instability to account for superoutbursts in the SU UMa stars predicts embedded precursors only for short orbital period dwarf novae, therefore the presence of embedded precursors in long orbital period systems - U Gem and SS Cyg - argues for a more general mechanism to explain long outbursts.

A large ungated TPC with GEM amplification

Science.gov (United States)

Berger, M.; Ball, M.; Fabbietti, L.; Ketzer, B.; Arora, R.; Beck, R.; Böhmer, F. V.; Chen, J.-C.; Cusanno, F.; Dørheim, S.; García, F.; Hehner, J.; Herrmann, N.; Höppner, C.; Kaiser, D.; Kis̆, M.; Kleipa, V.; Konorov, I.; Kunkel, J.; Kurz, N.; Leifels, Y.; Müllner, P.; Münzer, R.; Neubert, S.; Rauch, J.; Schmidt, C. J.; Schmitz, R.; Soyk, D.; Vandenbroucke, M.; Voss, B.; Walther, D.; Zmeskal, J.

2017-10-01

A Time Projection Chamber (TPC) is an ideal device for the detection of charged particle tracks in a large volume covering a solid angle of almost 4 π. The high density of hits on a given particle track facilitates the task of pattern recognition in a high-occupancy environment and in addition provides particle identification by measuring the specific energy loss for each track. For these reasons, TPCs with Multiwire Proportional Chamber (MWPC) amplification have been and are widely used in experiments recording heavy-ion collisions. A significant drawback, however, is the large dead time of the order of 1 ms per event generated by the use of a gating grid, which is mandatory to prevent ions created in the amplification region from drifting back into the drift volume, where they would severely distort the drift path of subsequent tracks. For experiments with higher event rates this concept of a conventional TPC operating with a triggered gating grid can therefore not be applied without a significant loss of data. A continuous readout of the signals is the more appropriate way of operation. This, however, constitutes a change of paradigm with considerable challenges to be met concerning the amplification region, the design and bandwidth of the readout electronics, and the data handling. A mandatory prerequisite for such an operation is a sufficiently good suppression of the ion backflow from the avalanche region, which otherwise limits the tracking and particle identification capabilities of such a detector. Gas Electron Multipliers (GEM) are a promising candidate to combine excellent spatial resolution with an intrinsic suppression of ions. In this paper we describe the design, construction and the commissioning of a large TPC with GEM amplification and without gating grid (GEM-TPC). The design requirements have driven innovations in the construction of a light-weight field-cage, a supporting media flange, the GEM amplification and the readout system, which are

Analysis of GEM properties and development of a GEM support structure for the ILD time projection chamber

International Nuclear Information System (INIS)

Hallermann, Lea

2010-04-01

In the concept of the International Large Detector (ILD), developed for the International Linear Collider (ILC) a Time Projection Chamber (TPC) is envisaged as main tracking detector. Such gaseous detectors have to be equipped with amplification devices in order to enlarge the amount of charge, which is set free by ionization caused by traversing charged particles. Micro Pattern Gas Detectors (MPGDs) will be used in the ILD TPC as amplification stage. In this thesis, Gas Electron Multipliers (GEMs) - one specific MPGD species - are analyzed concerning various properties. Effective gains and energy resolutions are compared for GEM foils produced by different manufacturers. A good understanding of these observables is obtained by interpretation of the results with the help of geometrical parameters. Height profile measurements of GEM foils have been performed for the first time and the impact of non perfect flat GEMs is analyzed, especially on dE/dx determination and drift field quality. The results emphasize the need of a flat installation of GEMs in TPCs. As a consequence, a new mounting device has been developed to ensure flatness and to provide a method to cover large readout areas, as in the ILD TPC, by introducing the least possible amount of dead material into the detector. The developed structure has been tested in a TPC protoype, taking cosmic muon data. The influence of the mounting on track reconstruction, single point resolution, tracking efficiency and dE/dx measurements is quantified. The developed mounting is applicable in a large scale TPC, if some design considerations are taken into account. (orig.)

Analysis of GEM properties and development of a GEM support structure for the ILD time projection chamber

Energy Technology Data Exchange (ETDEWEB)

Hallermann, Lea

2010-04-15

In the concept of the International Large Detector (ILD), developed for the International Linear Collider (ILC) a Time Projection Chamber (TPC) is envisaged as main tracking detector. Such gaseous detectors have to be equipped with amplification devices in order to enlarge the amount of charge, which is set free by ionization caused by traversing charged particles. Micro Pattern Gas Detectors (MPGDs) will be used in the ILD TPC as amplification stage. In this thesis, Gas Electron Multipliers (GEMs) - one specific MPGD species - are analyzed concerning various properties. Effective gains and energy resolutions are compared for GEM foils produced by different manufacturers. A good understanding of these observables is obtained by interpretation of the results with the help of geometrical parameters. Height profile measurements of GEM foils have been performed for the first time and the impact of non perfect flat GEMs is analyzed, especially on dE/dx determination and drift field quality. The results emphasize the need of a flat installation of GEMs in TPCs. As a consequence, a new mounting device has been developed to ensure flatness and to provide a method to cover large readout areas, as in the ILD TPC, by introducing the least possible amount of dead material into the detector. The developed structure has been tested in a TPC protoype, taking cosmic muon data. The influence of the mounting on track reconstruction, single point resolution, tracking efficiency and dE/dx measurements is quantified. The developed mounting is applicable in a large scale TPC, if some design considerations are taken into account. (orig.)

The GEM-Mars general circulation model for Mars: Description and evaluation

Science.gov (United States)

Neary, L.; Daerden, F.

2018-01-01

GEM-Mars is a gridpoint-based three-dimensional general circulation model (GCM) of the Mars atmosphere extending from the surface to approximately 150 km based on the GEM (Global Environmental Multiscale) model, part of the operational weather forecasting and data assimilation system for Canada. After the initial modification for Mars, the model has undergone considerable changes. GEM-Mars is now based on GEM 4.2.0 and many physical parameterizations have been added for Mars-specific atmospheric processes and surface-atmosphere exchange. The model simulates interactive carbon dioxide-, dust-, water- and atmospheric chemistry cycles. Dust and water ice clouds are radiatively active. Size distributed dust is lifted by saltation and dust devils. The model includes 16 chemical species (CO2, Argon, N2, O2, CO, H2O, CH4, O3, O(1D), O, H, H2, OH, HO2, H2O2 and O2(a1Δg)) and has fully interactive photochemistry (15 reactions) and gas-phase chemistry (31 reactions). GEM-Mars provides a good simulation of the water and ozone cycles. A variety of other passive tracers can be included for dedicated studies, such as the emission of methane. The model has both a hydrostatic and non-hydrostatic formulation, and together with a flexible grid definition provides a single platform for simulations on a variety of horizontal scales. The model code is fully parallelized using OMP and MPI. Model results are evaluated by comparison to a selection of observations from instruments on the surface and in orbit, relating to atmosphere and surface temperature and pressure, dust and ice content, polar ice mass, polar argon, and global water and ozone vertical columns. GEM-Mars will play an integral part in the analysis and interpretation of data that is received by the NOMAD spectrometer on the ESA-Roskosmos ExoMars Trace Gas Orbiter. The present paper provides an overview of the current status and capabilities of the GEM-Mars model and lays the foundations for more in-depth studies in support

Improved model of the Earth's gravitational field: GEM-T1

International Nuclear Information System (INIS)

Marsh, J.G.; Lerch, F.J.; Christodoulidis, D.C.

1987-07-01

Goddard Earth Model T1 (GEM-T1), which was developed from an analysis of direct satellite tracking observations, is the first in a new series of such models. GEM-T1 is complete to degree and order 36. It was developed using consistent reference parameters and extensive earth and ocean tidal models. It was simultaneously solved for gravitational and tidal terms, earth orientation parameters, and the orbital parameters of 580 individual satellite arcs. The solution used only satellite tracking data acquired on 17 different satellites and is predominantly based upon the precise laser data taken by third generation systems. In all, 800,000 observations were used. A major improvement in field accuracy was obtained. For marine geodetic applications, long wavelength geoidal modeling is twice as good as in earlier satellite-only GEM models. Orbit determination accuracy has also been substantially advanced over a wide range of satellites that have been tested

Global Entrepreneurship Monitor 2009 Executive Report.

NARCIS (Netherlands)

Bosma, N.S.; Levie, J.

2010-01-01

The Global Entrepreneurship Monitor (GEM) is the world’s leading research consortium dedicated to understanding the relationship between entrepreneurship and national economic development. For the past ten years GEM reports have been the only source of comparable data across a large variety of

GEM Detectors in the Experiments at e+e- Colliders in BINP

CERN Document Server

Maltsev, T V

2017-01-01

Micro-pattern gaseous detectors possess a high spatial resolution in tens micron scale together with high rate capability up to 107 cm-2s-1. In addition, they have all advantages of gaseous detectors, such as relatively low costs per unit area, the possibility to equip a large area as well as a high uniformity. Cascaded Gas Electron Multiplier (GEM) based detectors are used in the collider experiments at Budker Institute of Nuclear Physics (BINP), and they are being developed for a number of new projects. In this article the review of GEM based detectors for the tagging system of the KEDR experiment at the VEPP-4M collider and for the DEUTERON facility at the VEPP-3 storage ring is presented. The GEM detector application of the CMD-3 detector upgrade at the VEPP-2000 collider and the Super τ Factory detector are discussed.

A FPGA-based signal processing unit for a GEM array detector

International Nuclear Information System (INIS)

Yen, W.W.; Chou, H.P.

2013-06-01

in the present study, a signal processing unit for a GEM one-dimensional array detector is presented to measure the trajectory of photoelectrons produced by cosmic X-rays. The present GEM array detector system has 16 signal channels. The front-end unit provides timing signals from trigger units and energy signals from charge sensitive amplifies. The prototype of the processing unit is implemented using commercial field programmable gate array circuit boards. The FPGA based system is linked to a personal computer for testing and data analysis. Tests using simulated signals indicated that the FPGA-based signal processing unit has a good linearity and is flexible for parameter adjustment for various experimental conditions (authors)

Studies of aging and HV break down problems during development and operation of MSGC and GEM detectors for the inner tracking system of HERA-B

International Nuclear Information System (INIS)

Bagaturia, Y.; Baruth, O.; Dreis, H.B.; Eisele, F.; Gorbunov, I.; Gradl, S.; Gradl, W.; Hausmann, S.; Hildebrandt, M.; Hott, T.; Keller, S.; Krauss, C.; Lomonosov, B.; Negodaev, M.; Richter, C.; Robmann, P.; Schmidt, B.; Straumann, U.; Truoel, P.; Visbeck, S.; Walter, T.; Werner, C.; Werthenbach, U.; Zech, G.; Zeuner, T.; Ziegler, M.

2002-01-01

The results of 5 years of development of the inner tracking system of the HERA-B experiment and first experience from the data taking period of the year 2000 are reported. The system contains 184 chambers, covering a sensitive area of about (20x20) cm 2 each. The detector is based on microstrip gas counters (MSGCs) with diamond-like coated (DLC) glass wafers and gas electron multipliers (GEMs). The main problems in the development phase were gas discharges in intense hadron beams and aging in a high radiation dose environment. The observation of gas discharges which damage the electrode structure of the MSGC led to the addition of the GEM as a first amplification step. Spurious sparking at the GEM cannot be avoided completely. It does not affect the GEM itself but can produce secondary damage of the MSGC if the electric field between the GEM and the MSGC is above a threshold depending on the operation conditions. We observed that aging does not only depend on the dose but also on the spot size of the irradiated area. Ar-DME mixtures had to be abandoned whereas a mixture of 70% Ar and 30% CO 2 showed no serious aging effects up to about 40 mC/cm deposited charge on the anodes. X-ray measurements indicate that the DLC of the MSGC is deteriorated by the gas amplification process. As a consequence, long-term gain variations are expected. The Inner Tracker has successfully participated in the data taking at HERA-B during summer 2000

Studies of aging and HV break down problems during development and operation of MSGC and GEM detectors for the inner tracking system of HERA-B

Energy Technology Data Exchange (ETDEWEB)

Bagaturia, Y.; Baruth, O.; Dreis, H.B.; Eisele, F.; Gorbunov, I.; Gradl, S.; Gradl, W.; Hausmann, S.; Hildebrandt, M.; Hott, T.; Keller, S.; Krauss, C.; Lomonosov, B.; Negodaev, M.; Richter, C.; Robmann, P.; Schmidt, B.; Straumann, U.; Truoel, P.; Visbeck, S.; Walter, T.; Werner, C.; Werthenbach, U.; Zech, G. E-mail: zech@physik.uni-siegen.de; Zeuner, T.; Ziegler, M

2002-09-01

The results of 5 years of development of the inner tracking system of the HERA-B experiment and first experience from the data taking period of the year 2000 are reported. The system contains 184 chambers, covering a sensitive area of about (20x20) cm{sup 2} each. The detector is based on microstrip gas counters (MSGCs) with diamond-like coated (DLC) glass wafers and gas electron multipliers (GEMs). The main problems in the development phase were gas discharges in intense hadron beams and aging in a high radiation dose environment. The observation of gas discharges which damage the electrode structure of the MSGC led to the addition of the GEM as a first amplification step. Spurious sparking at the GEM cannot be avoided completely. It does not affect the GEM itself but can produce secondary damage of the MSGC if the electric field between the GEM and the MSGC is above a threshold depending on the operation conditions. We observed that aging does not only depend on the dose but also on the spot size of the irradiated area. Ar-DME mixtures had to be abandoned whereas a mixture of 70% Ar and 30% CO{sub 2} showed no serious aging effects up to about 40 mC/cm deposited charge on the anodes. X-ray measurements indicate that the DLC of the MSGC is deteriorated by the gas amplification process. As a consequence, long-term gain variations are expected. The Inner Tracker has successfully participated in the data taking at HERA-B during summer 2000.

A PHOTOMETRIC STUDY OF THE ALGOL-TYPE BINARY FG Gem

International Nuclear Information System (INIS)

Zhang, J.; Qian, S.-B.

2013-01-01

High-quality three-color light curves of the binary FG Gem were measured and analyzed. A new method based on extensive searching of isochrones was used to investigate possible parameters for the binary. FG Gem is found to be an Algol-type semi-detached binary system with a primary star temperature of 8200 K and a mass ratio of 0.41(1). The correctness and reliability of our result requires the verification of precision spectroscopy or standard star observations. We investigate a new possible cause for the orbital period variations based on times of minimum light data. It is suggested from the quantitative analysis that variations in the orbital period can be explained by intermittent mass transfer and angular momentum loss from stellar winds leaving the system on rotating magnetic fields.

Game programming gems

CERN Document Server

DeLoura, Mark

2000-01-01

For the countless tasks involved in creating a game engine there are an equal number of possible solutions. But instead of spending hours and hours trying to develop your own answers, now you can find out how the pros do it! Game Programming Gems is a hands-on, comprehensive resource packed with a variety of game programming algorithms written by experts from the game industry and edited by Mark DeLoura, former software engineering lead for Nintendo of America, Inc. and now the newly appointed editor-in-chief of Game Developer magazine. From animation and artificial intelligence to Z-buffering, lighting calculations, weather effects, curved surfaces, mutliple layer Internet gaming, to music and sound effects, all of the major techniques needed to develop a competitive game engine are covered. Game Programming Gems is written in a style accessible to individuals with a range of expertise levels. All of the source code for each algorithm is included and can be used by advanced programmers immediately. For aspir...

Project W-420 Ventilation Stack Monitoring System Year 2000 Compliance Assessment Project Plan

International Nuclear Information System (INIS)

BUSSELL, J.H.

1999-01-01

This assessment describes the potential Year 2000 (Y2K) problems and describes the methods for achieving Y2K Compliance for Project W-420, Ventilation Stack Monitoring Systems Upgrades. The purpose of this assessment is to give an overview of the project. This document will not be updated and any dates contained in this document are estimates and may change. The project work scope includes upgrades to ventilation stacks and generic effluent monitoring systems (GEMS) at the 244-A Double Contained Receiver Tank (DCRT), the 244-BX DCRT, the 244-CR Vault, tanks 241-C-105 and 241-C-106, the 244-S DCRT, and the 244-TX DCRT. A detailed description of system dates, functions, interfaces, potential Y2K problems, and date resolutions can not be described since the project is in the definitive design phase, This assessment will describe the methods, protocols, and practices to ensure that equipment and systems do not have Y2K problems

GEM - A novel gaseous particle detector

CERN Document Server

Meinschad, T

2005-01-01

The work carried out within the framework of this Ph.D. deals with the construction of gaseous prototype detectors using Gas Electron Multiplier electrodes for the amplification of charges released by ionizing particles. The Gas Electron Multiplier (GEM) is a thin metal-clad polymer foil, etched with a high density of narrow holes, typically 50-100mm-2. On the application of a potential difference between the conductive top and bottom sides each hole acts as independent proportional counter. This new fast device permits to reach large amplification factors at high rates with a strong photon and ion-mediated feedback suppression due to the avalanche confinement in the GEM-holes. Here, in particular studies have been performed, which should prove, that the GEM-technology is applicable for an efficient measurement of single Cherenkov photons. These UV-photons can be detected in different ways. An elegant solution to develop large area RICH-detectors is to evaporate a pad-segmented readout-cathode of a multi-wire...

Gain uniformity experimental study performed on triple-GEM gas detector

International Nuclear Information System (INIS)

Dong Liyuan; Qi Huirong; Lu Xinyu; Ouyang Qun; Chen Yuanbo; Li Yuhong

2012-01-01

With the application of the two-dimensional GEM gaseous detector in X-ray imaging, the correction method of gain uniformity caused by triple-GEM avalanche structures and electric field uniformity should be studied. The paper reported the study of the triple-GEM detector with effective area 100 mm × 100 mm used the Pad's size of 9.5 mm × 9.5 mm. In the test, 100 readout channels were designed. Results showed that gain remained stable over time; at air flow increases, gain from increases obviously to changes very little. Particularly, triple-GEM's gain uniformity was very good (more than 80%) and the range of energy resolution was from 0.18 to 0.2. To improve gain consistency of results, the difference value revised was obtained to be about 0.1 by the least square method. It provided a better method to improve gain uniformity of GEM detector. (authors)

A gravity model for crustal dynamics (GEM-L2)

Science.gov (United States)

Lerch, F. J.; Klosko, S. M.; Patel, G. B.; Wagner, C. A.

1985-01-01

The Laser Geodynamics Satellite (Lageos) was the first NASA satellite which was placed into orbit exclusively for laser ranging applications. Lageos was designed to permit extremely accurate measurements of the earth's rotation and the movement of the tectonic plates. The Goddard earth model, GEM-L2, was derived mainly on the basis of the precise laser ranging data taken on many satellites. Douglas et al. (1984) have demonstrated the utility of GEM-L2 in detecting the broadest ocean circulations. As Lageos data constitute the most extensive set of satellite laser observations ever collected, the incorporation of 2-1/2 years of these data into the Goddard earth models (GEM) has substantially advanced the geodynamical objectives. The present paper discusses the products of the GEM-L2 solution.

Benchmarking the CEMDATA07 database to model chemical degradation of concrete using GEMS and PHREEQC

International Nuclear Information System (INIS)

Jacques, Diederik; Wang, Lian; Martens, Evelien; Mallants, Dirk

2012-01-01

Thermodynamic equilibrium modelling of degradation of cement and concrete systems by chemically detrimental reactions as carbonation, sulphate attack and decalcification or leaching processes requires a consistent thermodynamic database with the relevant aqueous species, cement minerals and hydrates. The recent and consistent database CEMDATA07 is used as the basis in the studies of the Belgian near-surface disposal concept being developed by ONDRAF/NIRAS. The database is consistent with the thermodynamic data in the Nagra/PSI-Thermodynamic Database. When used with the GEMS thermodynamic code, thermodynamic modelling can be performed at temperatures different from the standard temperature of 25 C. GEMS calculates thermodynamic equilibrium by minimizing the Gibbs free energy of the system. Alternatively, thermodynamic equilibrium can also be calculated by solving a nonlinear system of mass balance equations and mass action equations, as is done in PHREEQC. A PHREEQC-database for the cement systems at temperatures different from 25 C is derived from the thermodynamic parameters and models from GEMS. A number of benchmark simulations using PHREEQC and GEM-Selektor were done to verify the implementation of the CEMDATA07 database in PHREEQC-databases. Simulations address a series of reactions that are relevant to the assessment of long-term cement and concrete durability. Verification calculations were performed for different systems with increasing complexity: CaO-SiO 2 -CO 2 , CaO-Al 2 O 3 -SO 3 -CO 2 , and CaO-SiO 2 -Al 2 O 3 -Fe 2 O 3 -MgO-SO 3 -CO 2 . Three types of chemical degradation processes were simulated: (1) carbonation by adding CO 2 to the bulk composition, (2) sulphate attack by adding SO 3 to the bulk composition, and (3) decalcification/leaching by putting the cement solid phase sequentially in contact with pure water. An excellent agreement between the simulations with GEMS and PHREEQC was obtained

A new design using GEM-based technology for the CMS experiment

Science.gov (United States)

Ressegotti, M.

2017-07-01

The muon system of the Compact Muon Solenoid (CMS) experiment at the LHC is currently not instrumented for pseudorapidity higher than |η|> 2.4. The main challenges to the installation of a detector in that position are the high particle flux to be sustained, a high level of radiation, and the ability to accomodate a multilevel detector into the small available space (less than 30 cm). A new back-to-back configuration of a Gas Electron Multiplier (GEM) detector is presented with the aim of developing a compact, multi-layer GEM detector. It is composed of two independent stacked triple-GEM detectors, positioned with the anodes toward the outside and sharing the same cathode plane, which is located at the center of the chamber, to reduce the total detector's thickness. A first prototype has been produced and tested with an X-Ray source and muon beam. First results on its performance are presented.

A new design using GEM-based technology for the CMS experiment

CERN Document Server

Ressegotti, Martina

2017-01-01

The muon system of the Compact Muon Solenoid (CMS) experiment at the LHC is currently not instrumented for pseudorapidity higher than abs(${\\eta}$)${ > 2.4}$. The main challenges to the installation of a detector in that position are the high particle flux to be sustained, a high level of radiation, and the ability to accomodate a multilevel detector into the small available space (less than 30 cm). A new back-to-back configuration of a Gas Electron Multiplier (GEM) detector is presented with the aim of developing a compact, multi-layer GEM detector. It is composed of two independent stacked triple-GEM detectors, positioned with the anodes toward the outside and sharing the same cathode plane, which is located at the center of the chamber, to reduce the total detector's thickness. A first prototype has been produced and tested with an X-Ray source and muon beam. First results on its performance are presented.

Numerical Investigation on Electron and Ion Transmission of GEM-based Detectors

Directory of Open Access Journals (Sweden)

Bhattacharya Purba

2018-01-01

Full Text Available ALICE at the LHC is planning a major upgrade of its detector systems, including the TPC, to cope with an increase of the LHC luminosity after 2018. Different R&D activities are currently concentrated on the adoption of the Gas Electron Multiplier (GEM as the gas amplification stage of the ALICE-TPC upgrade version. The major challenge is to have low ion feedback in the drift volume as well as to ensure a collection of good percentage of primary electrons in the signal generation process. In the present work, Garfield simulation framework has been adopted to numerically estimate the electron transparency and ion backflow fraction of GEM-based detectors. In this process, extensive simulations have been carried out to enrich our understanding of the complex physical processes occurring within single, triple and quadruple GEM detectors. A detailed study has been performed to observe the effect of detector geometry, field configuration and magnetic field on the above mentioned characteristics.

Numerical Investigation on Electron and Ion Transmission of GEM-based Detectors

Science.gov (United States)

Bhattacharya, Purba; Sahoo, Sumanya Sekhar; Biswas, Saikat; Mohanty, Bedangadas; Majumdar, Nayana; Mukhopadhyay, Supratik

2018-02-01

ALICE at the LHC is planning a major upgrade of its detector systems, including the TPC, to cope with an increase of the LHC luminosity after 2018. Different R&D activities are currently concentrated on the adoption of the Gas Electron Multiplier (GEM) as the gas amplification stage of the ALICE-TPC upgrade version. The major challenge is to have low ion feedback in the drift volume as well as to ensure a collection of good percentage of primary electrons in the signal generation process. In the present work, Garfield simulation framework has been adopted to numerically estimate the electron transparency and ion backflow fraction of GEM-based detectors. In this process, extensive simulations have been carried out to enrich our understanding of the complex physical processes occurring within single, triple and quadruple GEM detectors. A detailed study has been performed to observe the effect of detector geometry, field configuration and magnetic field on the above mentioned characteristics.

A triple GEM gamma camera for medical application

Energy Technology Data Exchange (ETDEWEB)

Anulli, F. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Balla, A. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Bencivenni, G. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Corradi, G. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); D' Ambrosio, C. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Domenici, D. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Felici, G. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Gatta, M. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Morone, M.C. [Dipartimento di Biopatologia e Diagnostica per immagini, Universita di Roma Tor Vergata (Italy); INFN - Sezione di Roma Tor Vergata (Italy); Murtas, F. [Laboratori Nazionali di Frascati INFN, Frascati (Italy)]. E-mail: fabrizio.murtas@lnf.infn.it; Schillaci, O. [Dipartimento di Biopatologia e Diagnostica per immagini, Universita di Roma Tor Vergata (Italy)

2007-03-01

A Gamma Camera for medical applications 10x10cm{sup 2} has been built using a triple GEM chamber prototype. The photon converters placed in front of the three GEM foils, has been realized with different technologies. The chamber, High Voltage supplied with a new active divider made in Frascati, is readout through 64 pads, 1mm{sup 2} wide, organized in a row of 8cm long, with LHCb ASDQ chip. This Gamma Camera can be used both for X-ray movie and PET-SPECT imaging; this chamber prototype is placed in a scanner system, creating images of 8x8cm{sup 2}. Several measurements have been performed using phantom and radioactive sources of Tc99m(140keV) and Na22(511keV). Results on spatial resolution and image reconstruction are presented.

X-Ray Polarimetry with GEMS

Science.gov (United States)

Strohmayer, Tod

2011-01-01

The polarization properties of cosmic X-ray sources are still largely unexplored. The Gravity and Extreme Magnetism SMEX (GEMS) will carry out the first sensitive X-ray polarization survey of a wide range of sources including; accreting compact objects (black holes and neutron stars), AGN, supernova remnants, magnetars and rotation-powered pulsars. GEMS employs grazing-incidence foil mirrors and novel time-projection chamber (TPC) polarimeters leveraging the photoelectric effect to achieve high polarization sensitivity in the 2 - 10 keV band. I will provide an update of the project status, illustrate the expected performance with several science examples, and provide a brief overview of the data analysis challenges

Simulation of the dielectric charging-up effect in a GEM detector

International Nuclear Information System (INIS)

Alfonsi, M.; Croci, G.; Duarte Pinto, S.; Rocco, E.; Ropelewski, L.; Sauli, F.; Veenhof, R.; Villa, M.

2012-01-01

The charging up effect is well-known in detectors containing dielectric materials and it is due to electrons and ions liberated in an avalanche and collected on the dielectric surfaces. In particular in Gas Electron Multiplier (GEM) based detectors, charges can be captured by the Kapton that separates top and bottom electrodes. The collection of a substantial number of charges on the dielectric surfaces induces a modification of the field inside the GEM holes that implies important consequences on some fundamental parameters such as the electron transparency and the effective gain. The correct simulation of this effect opens new ways to the detailed study of the processes that happens in a GEM-based detector and gives the possibility to optimise the GEM geometry in order to avoid it. This paper compares results of the measurements and the simulations, with and without the introduction of the charging-up effect, of the GEM electron transparency in the case of a single GEM detector. The introduction of the charging up effect in the simulation resulted to be crucial in order to get the proper agreement with the measurements. The measurements and simulations of the GEM effective gain will be the subject of a future work.

Toward improved guideline quality: using the COGS statement with GEM.

Science.gov (United States)

Shiffman, Richard N; Michel, Georges

2004-01-01

The Conference on Guideline Standardization (COGS) was convened to create a standardized documentation checklist for clinical practice guidelines in an effort to promote guideline quality and facilitate implementation. The statement was created by a multidisciplinary panel using a rigorous consensus development methodology. The Guideline Elements Model (GEM) provides a standardized approach to representing guideline documents using XML. In this work, we demonstrate the sufficiency of GEM for describing COGS components. Using the mapping between COGS and GEM elements we built an XSLT application to examine a guideline's adherence (or non-adherence) to the COGS checklist. Once a guideline has been marked up according to the GEM hierarchy, its knowledge content can be reused in multiple ways.

Performance of GEM detectors in high intensity particle beams

CERN Document Server

Bachmann, S; Ketzer, B; Deutel, M; Ropelewski, Leszek; Sauli, Fabio; Bondar, A E; Buzulutskov, A F; Shekhtman, L I; Sokolov, A; Tatarinov, A A; Vasilev, A; Kappler, S; Schulte, E C

2001-01-01

We describe extensive tests of Double GEM and Triple GEM detectors, including full size prototypes for the COMPASS experiment, exposed to high intensity muon, proton and pion beams at the Paul~Scherrer Institute and at CERN. The measurements aim at detecting problems possible under these operation conditions, the main concern being the occurrence of discharges induced by beam particles. Results on the dependence of the probability for induced discharges on the experimental environment are presented and discussed. Implications for the application of GEM~detectors in experiments at high luminosity colliders are illustrated.

Summer Student Project: GEM Simulation and Gas Mixture Characterization

CERN Document Server

Oviedo Perhavec, Juan Felipe

2013-01-01

Abstract This project is a numerical simulation approach to Gas Electron Multiplier (GEM) detectors design. GEMs are a type of gaseous ionization detector that have proposed as an upgrade for CMS muon endcap. The main advantages of this technology are high spatial and time resolution and outstanding aging resistance. In this context, fundamental physical behavior of a Gas Electron Multiplier (GEM) is analyzed using ANSYS and Garfield++ software coupling. Essential electron transport properties for several gas mixtures were computed as a function of varying electric and magnetic field using Garfield++ and Magboltz.

The optimisation of a water distribution system using Bentley WaterGEMS software

Directory of Open Access Journals (Sweden)

Świtnicka Karolina

2017-01-01

Full Text Available The proper maintenance of water distribution systems (WDSs requires from operators multiple actions in order to ensure optimal functioning. Usually, all requirements should be adjusted simultaneously. Therefore, the decision-making process is often supported by multi-criteria optimisation methods. Significant improvements of exploitation conditions of WDSs functioning can be achieved by connecting small water supply networks into group systems. Among many potential tools supporting advanced maintenance and management of WDSs, significant improvements have tools that can find the optimal solution by the implemented mechanism of metaheuristic methods, such as the genetic algorithm. In this paper, an exemplary WDS functioning optimisation is presented, in relevance to a group water supply system. The action range of optimised parameters included: maximisation of water flow velocity, regulation of pressure head, minimisation of water retention time in a network (water age and minimisation of pump energy consumption. All simulations were performed in Bentley WaterGEMS software.

Investigations of the long-term stability of a GEM-TPC

Energy Technology Data Exchange (ETDEWEB)

Fedorchuk, Oleksiy [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany); Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); Collaboration: LCTPC-Deutschland-Collaboration

2016-07-01

For the International Large Detector (ILD) at the planned International Linear Collider (ILC) a Time Projection Chamber (TPC) is foreseen as the main tracking detector. The gas amplification will be done by Micro Pattern Gaseous Detectors (MPGD). One option is to use Gas Electron Multipliers (GEM).While the applicability of GEMs for the gas amplification in a TPC readout has been shown, the focus of the current research is to improve the high voltage stability and reliability of the readout modules. This is a crucial requirement for the operation in the final ILD TPC. The main focus of the research presented in this talk is on studies of the discharge stability and operational features of large area 22 x 18 cm{sup 2} GEM foils. We present systematic studies of the stability of GEM foils under different operation conditions. These studies include measurements and calculations of the dynamic behavior of charges in the GEM foils after a trip. The results will be used to develop methods to avoid destructive discharges in the final readout module.

Irradiation study on GEM IPC preamp/shaper

International Nuclear Information System (INIS)

Kandasamy, A.

1995-01-01

The Preamplifier/Shaper Integrated Circuit for the GEM Interpolating Pad Chamber (IPC), designed by Paul. O'Connor, Brookhaven National Laboratory is for amplifying the charge signal from the Pad cathodes into a voltage pulse which goes to the Analog Random Access Memory (ARAM) integrated circuit. The GEM IPC integrated circuit has a SemiGaussian voltage pulse output with a 30ns shaping time. The integrated circuits were fabricated using Harris Semiconductors AVLSI1-RA process in-order for the electronics on the wafer to survive up to 2 mad of ionizing radiation during its operation life time. The details of the electronics on the GEM IPC integrated circuits is explained in the design memorandum by Paul. O'Connor. The purpose of this study is to determine the ability of the electronics on this IC fabricated using the above process to withstand ionizing radiation up to the above mentioned dose level

The Phases Differential Astrometry Data Archive. 4. The Triple Star Systems 63 Gem A and HR 2896

Science.gov (United States)

2010-12-01

3450 Massachusetts Avenue, NW, Washington, DC 20392-5420, USA; wih @usno.navy.mil 5 Division of Physics, Mathematics and Astronomy, 105-24, California...presented to aid in constraining the orbit and measuring the stellar masses. In fact, 63 Gem itself is a sextuple system: the hierarchical triple...that mutual inclination measurements have been rare is because of the observational challenges these sys- tems present. RV signals are largest for

GEM applications outside high energy physics

CERN Document Server

Duarte Pinto, Serge

2013-01-01

From its invention in 1997, the Gas Electron Multiplier has been applied in nuclear and high energy physics experiments. Over time however, other applications have also exploited the favorable properties of GEMs. The use of GEMs in these applications will be explained in principle and practice. This paper reviews applications in research, beam instrumentation and homeland security. The detectors described measure neutral radiations such as photons, x-rays, gamma rays and neutrons, as well as all kinds of charged radiation. This paper provides an overview of the still expanding range of possibilities of this versatile detector concept.

GEM-based gaseous photomultipliers for UV and visible photon imaging

International Nuclear Information System (INIS)

Moermann, D.; Balcerzyk, M.; Breskin, A.; Chechik, R.; Singh, B.K.; Buzulutskov, A.

2003-01-01

We present the current status of our research on GEM-based gaseous photomultipliers. Detectors combining multi-GEM electron multipliers with semi-transparent and reflective photocathodes are discussed. We present recent progress in extending the sensitivity of these detectors into the visible range. We demonstrate the long-term stability of an argon-sealed bi-alkali photo-diode and provide preliminary results of a gas-sealed Kapton-GEM detector with a bi-alkali photocathode. The problem of ion-induced secondary electron emission is addressed

Gas electron multiplier (GEM) operation with tissue-equivalent gases at various pressures

International Nuclear Information System (INIS)

Farahmand, M.; Bos, A.J.J.; Eijk, C.W.E. van

2003-01-01

We have studied the operation of two different Gas Electron Multiplier (GEM) structures in both methane and propane based Tissue-Equivalent (TE) gases at different pressures varying from 0.1 to 1 atm. This work was motivated to explore the possibility of using a GEM for a new type of Tissue Equivalent Proportional Counter. In methane based TE gas, a maximum safe GEM gain of 1.5x10 3 has been reached while in propane based TE gas this is 6x10 3 . These maxima have been reached at different gas pressures depending on GEM structure and TE gas. Furthermore, we observed a decrease of the GEM gain in time before it becomes stable. Charge up/polarisation effects can explain this

An Entrepreneurial Well-being Model based on GEM Data for Spain

Directory of Open Access Journals (Sweden)

José Manuel Sáiz-Álvarez

2014-03-01

Full Text Available The Economics of Happiness is one of the research areas of greatest growth in recent years. Throughout this work, a venture based model in which satisfaction of Spanish entrepreneurs with their professional life is performed. We analyze the responses of 9,989 entrepreneurs using data from the Global Entrepreneurship Monitor (GEM, and six hypothesis are discussed. The results show that, for the Spanish case, there is a strong consistency in the results the opportunity entrepreneurs present greater satisfaction than necessity entrepreneurs.

GEM-AQ/EC, an on-line global multi-scale chemical weather modelling system: model development and evaluation of global aerosol climatology

Directory of Open Access Journals (Sweden)

S. L. Gong

2012-09-01

Full Text Available A global air quality modeling system GEM-AQ/EC was developed by implementing tropospheric chemistry and aerosol processes on-line into the Global Environmental Multiscale weather prediction model – GEM. Due to the multi-scale features of the GEM, the integrated model, GEM-AQ/EC, is able to investigate chemical weather at scales from global to urban domains. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module CAM (The Canadian Aerosol Module with 5 aerosols types: sulphate, black carbon, organic carbon, sea-salt and soil dust. Monthly emission inventories of black carbon and organic carbon from boreal and temperate vegetation fires were assembled using the most reliable areas burned datasets by countries, from statistical databases and derived from remote sensing products of 1995–2004. The model was run for ten years from from 1995–2004 with re-analyzed meteorology on a global uniform 1° × 1° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. The simulating results were compared with various observations including surface network around the globe and satellite data. Regional features of global aerosols are reasonably captured including emission, surface concentrations and aerosol optical depth. For various types of aerosols, satisfactory correlations were achieved between modeled and observed with some degree of systematic bias possibly due to large uncertainties in the emissions used in this study. A global distribution of natural aerosol contributions to the total aerosols is obtained and compared with observations.

Simulation of space-charge effects in an ungated GEM-based TPC

Energy Technology Data Exchange (ETDEWEB)

Böhmer, F.V., E-mail: felix.boehmer@tum.de; Ball, M.; Dørheim, S.; Höppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Rauch, J.; Vandenbroucke, M.

2013-08-11

A fundamental limit to the application of Time Projection Chambers (TPCs) in high-rate experiments is the accumulation of slowly drifting ions in the active gas volume, which compromises the homogeneity of the drift field and hence the detector resolution. Conventionally, this problem is overcome by the use of ion-gating structures. This method, however, introduces large dead times and restricts trigger rates to a few hundred per second. The ion gate can be eliminated from the setup by the use of Gas Electron Multiplier (GEM) foils for gas amplification, which intrinsically suppress the backflow of ions. This makes the continuous operation of a TPC at high rates feasible. In this work, Monte Carlo simulations of the buildup of ion space charge in a GEM-based TPC and the correction of the resulting drift distortions are discussed, based on realistic numbers for the ion backflow in a triple-GEM amplification stack. A TPC in the future P{sup ¯}ANDA experiment at FAIR serves as an example for the experimental environment. The simulations show that space charge densities up to 65 fC cm{sup −3} are reached, leading to electron drift distortions of up to 10 mm. The application of a laser calibration system to correct these distortions is investigated. Based on full simulations of the detector physics and response, we show that it is possible to correct for the drift distortions and to maintain the good momentum resolution of the GEM-TPC.

Simulation of space-charge effects in an ungated GEM-based TPC

International Nuclear Information System (INIS)

Böhmer, F.V.; Ball, M.; Dørheim, S.; Höppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Rauch, J.; Vandenbroucke, M.

2013-01-01

A fundamental limit to the application of Time Projection Chambers (TPCs) in high-rate experiments is the accumulation of slowly drifting ions in the active gas volume, which compromises the homogeneity of the drift field and hence the detector resolution. Conventionally, this problem is overcome by the use of ion-gating structures. This method, however, introduces large dead times and restricts trigger rates to a few hundred per second. The ion gate can be eliminated from the setup by the use of Gas Electron Multiplier (GEM) foils for gas amplification, which intrinsically suppress the backflow of ions. This makes the continuous operation of a TPC at high rates feasible. In this work, Monte Carlo simulations of the buildup of ion space charge in a GEM-based TPC and the correction of the resulting drift distortions are discussed, based on realistic numbers for the ion backflow in a triple-GEM amplification stack. A TPC in the future P ¯ ANDA experiment at FAIR serves as an example for the experimental environment. The simulations show that space charge densities up to 65 fC cm −3 are reached, leading to electron drift distortions of up to 10 mm. The application of a laser calibration system to correct these distortions is investigated. Based on full simulations of the detector physics and response, we show that it is possible to correct for the drift distortions and to maintain the good momentum resolution of the GEM-TPC

The role of evaporites in the formation of gems during metamorphism of carbonate platforms: a review

Science.gov (United States)

Giuliani, Gaston; Dubessy, Jean; Ohnenstetter, Daniel; Banks, David; Branquet, Yannick; Feneyrol, Julien; Fallick, Anthony E.; Martelat, Jean-Emmanuel

2018-01-01

The mineral and fluid inclusions trapped by gemstones during the metamorphism of carbonate platform successions are precious markers for the understanding of gem genesis. The nature and chemical composition of inclusions highlight the major contribution of evaporites through dissolution or fusion, depending on the temperature of formation from greenschist to granulite facies. The fluids are highly saline NaCl-brines circulating either in an open system in the greenschist facies (Colombian and Afghan emeralds) and with huge fluid-rock metasomatic interactions, or sulphurous fluids (ruby, garnet tsavorite, zoisite tanzanite and lapis-lazuli) or molten salts formed in a closed system with a low fluid mobility (ruby in marble) in the conditions of the amphibolite to granulite facies. These chloride-fluoride-sulphate ± carbonate-rich fluids scavenged the metals essential for gem formation. At high temperature, the anions SO4 2-, NO3 -, BO3 - and F- are powerful fluxes which lower the temperature of chloride- and fluoride-rich ionic liquids. They provided transport over a very short distance of aluminium and/or silica and transition metals which are necessary for gem growth. In summary, the genetic models proposed for these high-value and ornamental gems underline the importance of the metamorphism of evaporites formed on continental carbonate shelves and emphasise the chemical power accompanying metamorphism at moderate to high temperatures of evaporite-rich and organic matter-rich protoliths to form gem minerals.

GEM, Fuel Cycle Cost and Economics for Thermal Reactor, Present Worth Analysis

International Nuclear Information System (INIS)

Hughes, J.A.; Hang, D.F.

1974-01-01

1- Description of problem or function: GEM is used to predict fuel cycle costs for any type nuclear system (i.e., BWR, HTGR, PWR, LMFBR, GCFR,... ). The current version is limited to thermal reactors. GEM is designed for production use by large utilities which have several reactor types on their system. GEM has been written so as to accommodate all major fuel management activities undertaken by a utility - (1) fuel bid analysis, (2) evaluation of actual day to day operation, and (3) system simulation and optimization studies. 2 - Method of solution: Costs are calculated using present-worth techniques and continuous compounding. The equations are based on an investor-owned utility capitalization structure which easily covers the range of industrial, private, and public (government) owned utilities. Three distinct types of analysis (cash flow, allocated costs, yearly cash flow) are performed, each yielding identical results. Using these as a basis many other analyses are undertaken. 3 - Restrictions on the complexity of the problem: Dimensions of all arrays are carried as variables throughout the analysis. The maximum size of each array is set by the user in program MAIN. Current values are set so that maxima are: 50 batches per case study, 20 year batch life, 30 year case study, 120 batch burn time-steps, 20 individual payments (sales) associated with each cost component

BoNus: Development and use of a radial TPC using cylindrical GEMs

International Nuclear Information System (INIS)

Fenker, H.; Baillie, N.; Bradshaw, P.; Bueltmann, S.; Burkert, V.; Christy, M.; Dodge, G.; Dutta, D.; Ent, R.; Evans, J.; Fersch, R.; Giovanetti, K.; Griffioen, K.; Ispiryan, M.; Jayalath, C.; Kalantarians, N.; Keppel, C.; Kuhn, S.; Niculescu, G.; Niculescu, I.

2008-01-01

A specialized system of target and detector was developed at Jefferson Lab to provide new access to information about neutron structure from electron-neutron interactions. It allows identification and measurement of spectator protons produced in e - d→e - p s X scattering events. The detector is a radial time-projection chamber optimized for the acceptance of low-momentum protons. Gas gain is provided by three cascaded curved Gas Electron Multipliers (GEMs), the first application of GEMs in any configuration other than flat. This article provides details about the development and construction of the detector, its performance, and the analysis of the data from the successful running of its first physics experiment

Development of single mask GEM foils in India

International Nuclear Information System (INIS)

Pant, L.M.; Mohanty, A.K.; Pinto, O.J.; Gadhadharan, S.; Menon, Pradeep; Sharma, Archana; Oliveira, Rui De; )

2014-01-01

There are various techniques available around the globe for making punch through holes for Micro Pattern Gas Detectors (MPGDs), such as Gas Electron Multipliers (GEMs). The GEM foils consists of 5 μm of Cu clad on both the sides of 50 μm polymide (PMMA/kapton) (5/50/5). At present these foils are developed in South Korea without having any adhesive between the Cu and polymide. The available techniques range from chemical etching, reactive plasma etching and laser etching. However, for GEM detectors, having an active area upto 5000 cm 2 , the chemical etching process using a Single Mask has been developed at CERN which is faster from the viewpoint of mass production of such foils for the upgrades which are foreseen in a couple of years with the Large Hadron Collider facility at CERN

The current status of the Gas Electron Multiplier (GEM) research at Kasetsart University, Thailand

Science.gov (United States)

Kumpiranon, P.; Kulasri, K.; Rittirong, A.; Saenboonruang, K.

2017-06-01

During the past decade, Gas Electron Multiplier (GEM) detectors have been greatly developed and utilized in numbers of applications including advanced nuclear and particle researches, medical imaging, astrophysics, and neutron detection for national security. Our GEM research group at the Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Thailand, realized in its excellent properties/potentials and started extensive researches on GEM detectors. To build a strong foundation on our research group, two 10 cm × 10 cm triple GEM detectors were characterized on their important properties including absolute gains and detection uniformity. Moreover, to widen applications of the GEM detector, our group had modified the GEM detector by introducing either solid or gaseous neutron converters to the detector so that the detector could effectively detect neutrons. These modifications included coating a thin film of 10B and natB to the GEM drift cathode for thermal neutron detection and flowing a gas mixture of He/CO2 (80:20 and 70:30) and C4H10/He/CO2 (7:70:23) for fast neutron detection. Results showed that the modified GEM-based neutron detector could detect both types of neutrons with different relative efficiencies and gains depending on thicknesses and types of neutron converters. This article discusses basic knowledge of the GEM detector, construction and testing procedures, results, and discussion.

Portable XRF: A Tool for the Study of Corundum Gems

Directory of Open Access Journals (Sweden)

Barone Germana

2017-09-01

Full Text Available Origin of gemstones is a key aspect not only in gemological field but also in Cultural Heritage studies, for the correct evaluation of precious artifacts. The studies on gems require the application of non-invasive and non-destructive methods; among them, portable spectroscopic techniques has been demonstrated as powerful tools, providing a fingerprint of gems for origin and provenance determination. In this study, portable XRF spectroscopy has been applied to test the potential of the technique for the origin determination of corundum gems. The obtained results allowed distinguishing natural and synthetic rubies and sapphires.

A Muon Tomography Station with GEM Detectors for Nuclear Threat Detection

Science.gov (United States)

Staib, Michael; Gnanvo, Kondo; Grasso, Leonard; Hohlmann, Marcus; Locke, Judson; Costa, Filippo; Martoiu, Sorin; Muller, Hans

2011-10-01

Muon tomography for homeland security aims at detecting well-shielded nuclear contraband in cargo and imaging it in 3D. The technique exploits multiple scattering of atmospheric cosmic ray muons, which is stronger in dense, high-Z nuclear materials, e.g. enriched uranium, than in low-Z and medium-Z shielding materials. We have constructed and operated a compact Muon Tomography Station (MTS) that tracks muons with six to ten 30 cm x 30 cm Triple Gas Electron Multiplier (GEM) detectors placed on the sides of a 27-liter cubic imaging volume. The 2D strip readouts of the GEMs achieve a spatial resolution of ˜130 μm in both dimensions and the station is operated at a muon trigger rate of ˜20 Hz. The 1,536 strips per GEM detector are read out with the first medium-size implementation of the Scalable Readout System (SRS) developed specifically for Micro-Pattern Gas Detectors by the RD51 collaboration at CERN. We discuss the performance of this MTS prototype and present experimental results on tomographic imaging of high-Z objects with and without shielding.

A GEM readout with radial zigzag strips and linear charge-sharing response

Science.gov (United States)

Zhang, Aiwu; Hohlmann, Marcus; Azmoun, Babak; Purschke, Martin L.; Woody, Craig

2018-04-01

We study the position sensitivity of radial zigzag strips intended to read out large GEM detectors for tracking at future experiments. Zigzag strips can cover a readout area with fewer strips than regular straight strips while maintaining good spatial resolution. Consequently, they can reduce the number of required electronic channels and related cost for large-area GEM detector systems. A non-linear relation between incident particle position and hit position measured from charge sharing among zigzag strips was observed in a previous study. We significantly reduce this non-linearity by improving the interleaving of adjacent physical zigzag strips. Zigzag readout structures are implemented on PCBs and on a flexible foil and are tested using a 10 cm × 10 cm triple-GEM detector scanned with a strongly collimated X-ray gun on a 2D motorized stage. Angular resolutions of 60-84 μrad are achieved with a 1.37 mrad angular strip pitch at a radius of 784 mm. On a linear scale this corresponds to resolutions below 100 μm.

Application of the GEM Inventory Data Capture Tools for Dynamic Vulnerability Assessment and Recovery Modelling

Science.gov (United States)

Verrucci, Enrica; Bevington, John; Vicini, Alessandro

2014-05-01

A set of open-source tools to create building exposure datasets for seismic risk assessment was developed from 2010-13 by the Inventory Data Capture Tools (IDCT) Risk Global Component of the Global Earthquake Model (GEM). The tools were designed to integrate data derived from remotely-sensed imagery, statistically-sampled in-situ field data of buildings to generate per-building and regional exposure data. A number of software tools were created to aid the development of these data, including mobile data capture tools for in-field structural assessment, and the Spatial Inventory Data Developer (SIDD) for creating "mapping schemes" - statistically-inferred distributions of building stock applied to areas of homogeneous urban land use. These tools were made publically available in January 2014. Exemplar implementations in Europe and Central Asia during the IDCT project highlighted several potential application areas beyond the original scope of the project. These are investigated here. We describe and demonstrate how the GEM-IDCT suite can be used extensively within the framework proposed by the EC-FP7 project SENSUM (Framework to integrate Space-based and in-situ sENSing for dynamic vUlnerability and recovery Monitoring). Specifically, applications in the areas of 1) dynamic vulnerability assessment (pre-event), and 2) recovery monitoring and evaluation (post-event) are discussed. Strategies for using the IDC Tools for these purposes are discussed. The results demonstrate the benefits of using advanced technology tools for data capture, especially in a systematic fashion using the taxonomic standards set by GEM. Originally designed for seismic risk assessment, it is clear the IDCT tools have relevance for multi-hazard risk assessment. When combined with a suitable sampling framework and applied to multi-temporal recovery monitoring, data generated from the tools can reveal spatio-temporal patterns in the quality of recovery activities and resilience trends can be

GEM-loaded magnetic albumin nanospheres modified with cetuximab for simultaneous targeting, magnetic resonance imaging, and double-targeted thermochemotherapy of pancreatic cancer cells

Directory of Open Access Journals (Sweden)

Wang L

2015-03-01

Full Text Available Ling Wang,1 Yanli An,2 Chenyan Yuan,3 Hao Zhang,2 Chen Liang,2 Fengan Ding,2 Qi Gao,1 Dongsheng Zhang4 1Department of Ultrasonography, Zhong Da Hospital, Medical School, Southeast University, Nanjing, People’s Republic of China; 2Medical School, Southeast University, Nanjing, People’s Republic of China; 3Department of Clinical Laboratory, Zhong Da Hospital, Medical School, Southeast University, Nanjing, People’s Republic of China; 4Jiangsu Key Laboratory for Biomaterials and Devices, Medical School, Southeast University, Nanjing, People’s Republic of China Background: Targeted delivery is a promising strategy to improve the diagnostic imaging and therapeutic effect of cancers. In this paper, novel cetuximab (C225-conjugated, gemcitabine (GEM-containing magnetic albumin nanospheres (C225-GEM/MANs were fabricated and applied as a theranostic nanocarrier to conduct simultaneous targeting, magnetic resonance imaging (MRI, and double-targeted thermochemotherapy against pancreatic cancer cells. Methods: Fe3O4 nanoparticles (NPs and GEM co-loaded albumin nanospheres (GEM/MANs were prepared, and then C225 was further conjugated to synthesize C225-GEM/MANs. Their morphology, mean particle size, GEM encapsulation ratio, specific cell-binding ability, and thermal dynamic profiles were characterized. The effects of discriminating different EGFR-expressing pancreatic cancer cells (AsPC-1 and MIA PaCa-2 and monitoring cellular targeting effects were assessed by targeted MRI. Lastly, the antitumor efficiency of double/C225/magnetic-targeted and nontargeted thermochemotherapy was compared with chemotherapy alone using 3-(4, 5-dimethyl-2-thiazolyl-2,5-diphenyl-2H-tetrazolium bromide (MTT and flow cytometry (FCM assay. Results: When treated with targeted nanospheres, AsPC-1 cells showed a significantly less intense MRI T2 signal than MIA PaCa-2 cells, while both cells had similar signal strength when incubated with nontargeted nanospheres. T2 signal

GEnomes Management Application (GEM.app): a new software tool for large-scale collaborative genome analysis.

Science.gov (United States)

Gonzalez, Michael A; Lebrigio, Rafael F Acosta; Van Booven, Derek; Ulloa, Rick H; Powell, Eric; Speziani, Fiorella; Tekin, Mustafa; Schüle, Rebecca; Züchner, Stephan

2013-06-01

Novel genes are now identified at a rapid pace for many Mendelian disorders, and increasingly, for genetically complex phenotypes. However, new challenges have also become evident: (1) effectively managing larger exome and/or genome datasets, especially for smaller labs; (2) direct hands-on analysis and contextual interpretation of variant data in large genomic datasets; and (3) many small and medium-sized clinical and research-based investigative teams around the world are generating data that, if combined and shared, will significantly increase the opportunities for the entire community to identify new genes. To address these challenges, we have developed GEnomes Management Application (GEM.app), a software tool to annotate, manage, visualize, and analyze large genomic datasets (https://genomics.med.miami.edu/). GEM.app currently contains ∼1,600 whole exomes from 50 different phenotypes studied by 40 principal investigators from 15 different countries. The focus of GEM.app is on user-friendly analysis for nonbioinformaticians to make next-generation sequencing data directly accessible. Yet, GEM.app provides powerful and flexible filter options, including single family filtering, across family/phenotype queries, nested filtering, and evaluation of segregation in families. In addition, the system is fast, obtaining results within 4 sec across ∼1,200 exomes. We believe that this system will further enhance identification of genetic causes of human disease. © 2013 Wiley Periodicals, Inc.

Graphics gems

CERN Document Server

Heckbert, Paul S

1994-01-01

Graphics Gems IV contains practical techniques for 2D and 3D modeling, animation, rendering, and image processing. The book presents articles on polygons and polyhedral; a mix of formulas, optimized algorithms, and tutorial information on the geometry of 2D, 3D, and n-D space; transformations; and parametric curves and surfaces. The text also includes articles on ray tracing; shading 3D models; and frame buffer techniques. Articles on image processing; algorithms for graphical layout; basic interpolation methods; and subroutine libraries for vector and matrix algebra are also demonstrated. Com

Combined readout of a triple-GEM detector

Science.gov (United States)

Antochi, V. C.; Baracchini, E.; Cavoto, G.; Di Marco, E.; Marafini, M.; Mazzitelli, G.; Pinci, D.; Renga, F.; Tomassini, S.; Voena, C.

2018-05-01

Optical readout of GEM based devices by means of high granularity and low noise CMOS sensors allows to obtain very interesting tracking performance. Space resolution of the order of tens of μm were measured on the GEM plane along with an energy resolution of 20%÷30%. The main limitation of CMOS sensors is represented by their poor information about time structure of the event. In this paper, the use of a concurrent light readout by means of a suitable photomultiplier and the acquisition of the electric signal induced on the GEM electrode are exploited to provide the necessary timing informations. The analysis of the PMT waveform allows a 3D reconstruction of each single clusters with a resolution on z of 100 μm. Moreover, from the PMT signals it is possible to obtain a fast reconstruction of the energy released within the detector with a resolution of the order of 25% even in the tens of keV range useful, for example, for triggering purpose.

GEM the gas electron multiplier

CERN Document Server

Sauli, Fabio

1997-01-01

We describe the basic structure and operation of a new device, the Gas Electron Multiplier. Consisting in a polymer foil, metal-clad on both sides and perforated by a high density of holes, the GEM mesh allows to pre-amplify charges released in the gas with good uniformity and energy. Coupled to a micro-strip plate, the pre-amplification element allows to preserve high rate capability and resolution at considerably lower operating voltages, thus completely eliminating discharges and instabilities. Several GEM grids can be operated in cascade; charge gains are large enough to allow detection of signals in the ionization mode on the last element, permitting the use of a simple printed circuit as read-out electrode. Two-dimensional read-out can then be easily implemented. A new generation of simple, reliable and cheap fast position sensitive detectors seems at hand.

Development of the GEM-TPC X-ray Polarimeter with the Scalable Readout System

Directory of Open Access Journals (Sweden)

Kitaguchi Takao

2018-01-01

Full Text Available We have developed a gaseous Time Projection Chamber (TPC containing a single-layered foil of a gas electron multiplier (GEM to open up a new window on cosmic X-ray polarimetry in the 2–10 keV band. The micro-pattern TPC polarimeter in combination with the Scalable Readout System produced by the RD51 collaboration has been built as an engineering model to optimize detector parameters and improve polarimeter sensitivity. The polarimeter was characterized with unpolarized X-rays from an X-ray generator in a laboratory and polarized X-rays on the BL32B2 beamline at the SPring-8 synchrotron radiation facility. Preliminary results show that the polarimeter has a comparable modulation factor to a prototype of the flight one.

Research of boron conversion coating in neutron detector with boron deposited GEM

International Nuclear Information System (INIS)

Ye Di; Sun Zhijia; Zhou Jianrong; Wang Yanfeng; Yang Guian; Xu Hong; Chen Yuanbai; Xiao Yu; Diao Xungang

2014-01-01

GEM is a flourishing new gas detector and nowadays its technology become more mature. It has outstanding properties, such as excellent position resolution, high counting rate, radiation resistance, simple and flexible signal readout, can be large-area detector, wide application range. Detector with boron deposited GEM uses multilayer GEM with deposited boron film as neutron conversion carrier which reads out the information of neutron shot from the readout electrode with gas amplification from every GEM layer. The detector is high performance which can meet the demands of neutron detector of a new generation. Boron deposited neutron conversion electrode with boron deposited cathode and GEM included is the core part of the detector. As boron is a high-melting-point metalloid (> 2 000 ℃), electroplating and thermal evaporation are inappropriate ways. So finding a way to deposit boron on electrode which can meet the demands become a key technology in the development of neutron detector with boron deposited GEM. Compared with evaporation, sputtering has features such as low deposition temperature, high film purity, nice adhesive, thus is appropriate for our research. Magnetron sputtering is a improved way of sputtering which can get lower sputtering air pressure and higher target voltage, so that we can get better films. Through deposit process, the research uses magnetron sputtering to deposit pure boron film on copper electrode and GEM film. This method can get high quality, nice adhere, high purity, controllable uniformity, low cost film with high speed film formation. (authors)

Performance of an optical readout GEM-based TPC

International Nuclear Information System (INIS)

Margato, L.M.S.; Fraga, F.A.F.; Fetal, S.T.G.; Fraga, M.M.F.R.; Balau, E.F.S.; Blanco, A.; Marques, R. Ferreira; Policarpo, A.J.P.L

2004-01-01

We report on the operation of a GEM-based small TPC using an optical readout. The detector was operated with a mixture of Ar+CF 4 using 5.48 MeV alpha particles obtained from a 241 Am source and the GEM scintillation was concurrently read by a CCD camera and a photomultiplier. Precision collimators were used to define the track orientation. Qualitative results on the accuracy of the track angle, length and charge deposition measurements are presented

Gaseous elemental mercury (GEM emissions from snow surfaces in northern New York.

Directory of Open Access Journals (Sweden)

J Alexander Maxwell

Full Text Available Snow surface-to-air exchange of gaseous elemental mercury (GEM was measured using a modified Teflon fluorinated ethylene propylene (FEP dynamic flux chamber (DFC in a remote, open site in Potsdam, New York. Sampling was conducted during the winter months of 2011. The inlet and outlet of the DFC were coupled with a Tekran Model 2537A mercury (Hg vapor analyzer using a Tekran Model 1110 two port synchronized sampler. The surface GEM flux ranged from -4.47 ng m(-2 hr(-1 to 9.89 ng m(-2 hr(-1. For most sample periods, daytime GEM flux was strongly correlated with solar radiation. The average nighttime GEM flux was slightly negative and was not well correlated with any of the measured meteorological variables. Preliminary, empirical models were developed to estimate GEM emissions from snow surfaces in northern New York. These models suggest that most, if not all, of the Hg deposited with and to snow is reemitted to the atmosphere.

Gaseous elemental mercury (GEM) emissions from snow surfaces in northern New York.

Science.gov (United States)

Maxwell, J Alexander; Holsen, Thomas M; Mondal, Sumona

2013-01-01

Snow surface-to-air exchange of gaseous elemental mercury (GEM) was measured using a modified Teflon fluorinated ethylene propylene (FEP) dynamic flux chamber (DFC) in a remote, open site in Potsdam, New York. Sampling was conducted during the winter months of 2011. The inlet and outlet of the DFC were coupled with a Tekran Model 2537A mercury (Hg) vapor analyzer using a Tekran Model 1110 two port synchronized sampler. The surface GEM flux ranged from -4.47 ng m(-2) hr(-1) to 9.89 ng m(-2) hr(-1). For most sample periods, daytime GEM flux was strongly correlated with solar radiation. The average nighttime GEM flux was slightly negative and was not well correlated with any of the measured meteorological variables. Preliminary, empirical models were developed to estimate GEM emissions from snow surfaces in northern New York. These models suggest that most, if not all, of the Hg deposited with and to snow is reemitted to the atmosphere.

Performance of the full size nGEM detector for the SPIDER experiment

Energy Technology Data Exchange (ETDEWEB)

Muraro, A., E-mail: muraro@ifp.cnr.it [Istituto di Fisica del Plasma “P. Caldirola” – CNR, Milan (Italy); Dipartimento di Fisica “G. Occhialini”, University of Milano-Bicocca (Italy); Croci, G. [Istituto di Fisica del Plasma “P. Caldirola” – CNR, Milan (Italy); Dipartimento di Fisica “G. Occhialini”, University of Milano-Bicocca (Italy); Sez. INFN Milano-Bicocca, Milano (Italy); Albani, G. [Dipartimento di Fisica “G. Occhialini”, University of Milano-Bicocca (Italy); Claps, G. [Laboratori Nazionali di Frascati – INFN, Frascati (Italy); Cavenago, M. [Laboratori Nazionali di Legnaro – INFN, Legnaro (Italy); Cazzaniga, C. [Dipartimento di Fisica “G. Occhialini”, University of Milano-Bicocca (Italy); Dalla Palma, M. [Consorzio RFX, Padova (Italy); Grosso, G. [Istituto di Fisica del Plasma “P. Caldirola” – CNR, Milan (Italy); Murtas, F. [Laboratori Nazionali di Frascati – INFN, Frascati (Italy); Pasqualotto, R. [Consorzio RFX, Padova (Italy); Perelli Cippo, E. [Istituto di Fisica del Plasma “P. Caldirola” – CNR, Milan (Italy); Rebai, M. [Dipartimento di Fisica “G. Occhialini”, University of Milano-Bicocca (Italy); Tardocchi, M.; Tollin, M. [Istituto di Fisica del Plasma “P. Caldirola” – CNR, Milan (Italy); Gorini, G. [Dipartimento di Fisica “G. Occhialini”, University of Milano-Bicocca (Italy); Sez. INFN Milano-Bicocca, Milano (Italy)

2016-03-21

The ITER neutral beam test facility under construction in Padova will host two experimental devices: SPIDER, a 100 kV negative H/D RF beam source, and MITICA, a full scale, 1 MeV deuterium beam injector. SPIDER will start operations in 2016 while MITICA is expected to start during 2019. Both devices feature a beam dump used to stop the produced deuteron beam. Detection of fusion neutrons produced between beam-deuterons and dump-implanted deuterons will be used as a means to resolve the horizontal beam intensity profile. The neutron detection system will be placed right behind the beam dump, as close to the neutron emitting surface as possible thus providing the map of the neutron emission on the beam dump surface. The system uses nGEM neutron detectors. These are Gas Electron Multiplier detectors equipped with a cathode that also serves as neutron–proton converter foil. The cathode is designed to ensure that most of the detected neutrons at a point of the nGEM surface are emitted from the corresponding beamlet footprint (with dimensions of about 40×22 mm{sup 2}) on the dump front surface. The size of the nGEM detector for SPIDER is 352 mm×200 mm. Several smaller size prototypes have been successfully made in the last years and the experience gained on these detectors has led to the production of the full size detector for SPIDER during 2014. This nGEM has a read-out board made of 256 pads (arranged in a 16×16 matrix) each with a dimension of 22 mm×13 mm. This paper describes the production of this detector and its tests (in terms of beam profile reconstruction capability, uniformity over the active area, gamma rejection capability and time stability) performed on the ROTAX beam-line at the ISIS spallation source (Didcot-UK).

Performance of the full size nGEM detector for the SPIDER experiment

International Nuclear Information System (INIS)

Muraro, A.; Croci, G.; Albani, G.; Claps, G.; Cavenago, M.; Cazzaniga, C.; Dalla Palma, M.; Grosso, G.; Murtas, F.; Pasqualotto, R.; Perelli Cippo, E.; Rebai, M.; Tardocchi, M.; Tollin, M.; Gorini, G.

2016-01-01

The ITER neutral beam test facility under construction in Padova will host two experimental devices: SPIDER, a 100 kV negative H/D RF beam source, and MITICA, a full scale, 1 MeV deuterium beam injector. SPIDER will start operations in 2016 while MITICA is expected to start during 2019. Both devices feature a beam dump used to stop the produced deuteron beam. Detection of fusion neutrons produced between beam-deuterons and dump-implanted deuterons will be used as a means to resolve the horizontal beam intensity profile. The neutron detection system will be placed right behind the beam dump, as close to the neutron emitting surface as possible thus providing the map of the neutron emission on the beam dump surface. The system uses nGEM neutron detectors. These are Gas Electron Multiplier detectors equipped with a cathode that also serves as neutron–proton converter foil. The cathode is designed to ensure that most of the detected neutrons at a point of the nGEM surface are emitted from the corresponding beamlet footprint (with dimensions of about 40×22 mm"2) on the dump front surface. The size of the nGEM detector for SPIDER is 352 mm×200 mm. Several smaller size prototypes have been successfully made in the last years and the experience gained on these detectors has led to the production of the full size detector for SPIDER during 2014. This nGEM has a read-out board made of 256 pads (arranged in a 16×16 matrix) each with a dimension of 22 mm×13 mm. This paper describes the production of this detector and its tests (in terms of beam profile reconstruction capability, uniformity over the active area, gamma rejection capability and time stability) performed on the ROTAX beam-line at the ISIS spallation source (Didcot-UK).

GEM Foil Quality Assurance For The ALICE TPC Upgrade

Science.gov (United States)

Brücken, Erik; Hildén, Timo

2018-02-01

The ALICE (A Large Ion Collider Experiment) experiment at the Large Hadron Collider (LHC) at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC) of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2) the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC) -based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz). The new ReadOut Chamber (ROC) design is based on Gas Electron Multiplier (GEM) technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, necessitates thorough Quality Assurance (QA) measures. The QA scheme, developed by the ALICE collaboration, will be presented in detail.

GEM Foil Quality Assurance For The ALICE TPC Upgrade

Directory of Open Access Journals (Sweden)

Brücken Erik

2018-01-01

Full Text Available The ALICE (A Large Ion Collider Experiment experiment at the Large Hadron Collider (LHC at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2 the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC –based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz. The new ReadOut Chamber (ROC design is based on Gas Electron Multiplier (GEM technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, necessitates thorough Quality Assurance (QA measures. The QA scheme, developed by the ALICE collaboration, will be presented in detail.

A GEM Detector System for an Upgrade of the High-eta Muon Endcap Stations GE1/1 + ME1/1 in CMS

CERN Document Server

Abbaneo, D; Aspell, P.; Bianco, S.; Hoepfner, K.; Hohlmann, M.; Maggi, M.; De Lentdecker, G.; Safonov, A.; Sharma, A.; Tytgat, M.

2012-01-01

Based on the CMS Upgrade R&D Proposal RD10.02, we describe the motivation and main features of the CMS GEM Project for LS2 and propose the addition of a full GE1/12 detector station comprising Gas Electron Multiplier (GEM) chambers to the forward muon system of CMS. The limitations of the currently existing forward muon detector when operating at increasingly high luminosity expected after LS1 are laid out followed by a brief description of the anticipated performance improvements achievable with a GE1/1 station. The second part describes the detector system followed by an overview of electronics and associated services including a discussion of the schedule and cost of the project. Plans for a precursor demonstrator installation in LS1 are presented. This proposal is intended as a concise follow-up of the detailed document CMS-IN-2012-023. If approved, this is to be followed by a detailed Technical Design Report.

OLYMPUS luminosity monitoring

Energy Technology Data Exchange (ETDEWEB)

Ates, Ozgur [Hampton University, Hampton, Virginia (United States); Collaboration: OLYMPUS-Collaboration

2013-07-01

The OLYMPUS experiment at DESY has been measuring the ratio of positron-proton and electron-proton elastic scattering cross sections to quantify the effect of two-photon exchange, which is widely considered to be responsible for the discrepancy between measurements of the proton electric to magnetic form factor ratio with the Rosenbluth and polarization transfer methods. In order to control the systematic uncertainties to the percent level, the luminosities are monitored redundantly with high precision by measuring the rates for symmetric Moller and Bhabha scattering, and by measuring the ep-elastic count rates at forward angles and low momentum transfer with tracking telescopes based on GEM (Gas Electron Multiplier) and MWPC (Multi Wire Proportional Chamber) technology. During two data taking periods, performances of GEM and MWPC luminosity monitors are presented.

High voltage distribution scheme for large size GEM detector

International Nuclear Information System (INIS)

Saini, J.; Kumar, A.; Dubey, A.K.; Negi, V.S.; Chattopadhyay, S.

2016-01-01

Gas Electron Multiplier (GEM) detectors will be used for Muon tracking in the Compressed Baryonic Matter (CBM) experiment at the Facility for Anti-proton Ion Research (FAIR) at Darmstadt, Germany. The sizes of the detector modules in the Muon chambers are of the order of 1 metre x 0.5 metre. For construction of these chambers, three GEM foils are used per chamber. These foils are made by two layered 50μm thin kapton foil. Each GEM foil has millions of holes on it. In such a large scale manufacturing of the foils, even after stringent quality controls, some of the holes may still have defects or defects might develop over the time with operating conditions. These defects may result in short-circuit of the entire GEM foil. A short even in a single hole will make entire foil un-usable. To reduce such occurrences, high voltage (HV) segmentation within the foils has been introduced. These segments are powered either by individual HV supply per segment or through an active HV distribution to manage such a large number of segments across the foil. Individual supplies apart from being costly, are highly complex to implement. Additionally, CBM will have high intensity of particles bombarding on the detector causing the change of resistive chain current feeding the GEM detector with the variation in the intensity. This leads to voltage fluctuations across the foil resulting in the gain variation with the particle intensity. Hence, a low cost active HV distribution is designed to take care of the above discussed issues

Experiment study on the thick GEM-like multiplier for X-ray photoelectrons energy deposition gaining

International Nuclear Information System (INIS)

Zhu Pengfei; Ye Yan; Long Yan; Cao Ningxiang; Jia Xing; Li Jianfeng

2009-01-01

The GEM is a novel detector with high gain,high time and location resolution. Imitating the structure of the GEM, a thick GEM-like multiplier which has the similar function with that of the GEM is designed and manufactured. The characteristics of the thick GEM-like multiplier increasing electron energy deposition in absorbing medium has been experimentally studied. The results indicate that the energy deposition gain of x-ray photoelectron in medium is apparent, and the maximum energy deposition can increase by more than 40%. Some suggestions of further increasing the energy deposition are given, and the future application of the way of increasing the x-ray photoelectron energy deposition by the thick GEM-like multiplier in hard x-ray imaging is prospected. (authors)

Analysis of data recorded by the LCTPC equipped with a two layer GEM-system

CERN Document Server

Ljunggren, M

2012-01-01

wire based readout. The prototype TPC is placed in a 1 Tesla magnet at DESY and tested using an electron beam. Analyses of data taken during two different measurement series, in 2009 and 2010, are presented here. The TPC was instrumented with a two layer GEM system and read out using modified electronics from the ALICE experiment, including the programmable charge sensitive preamp-shaper PCA16. The PCA16 chip has a number of programmable parameters which allows studies to determine the settings optimal to the final TPC. Here, the impact of the shaping time on the space resolution in the drift direction was studied. It was found that a shaping time of 60 ns is the b...

Gender Evaluation Methodology (GEM) | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

2011-10-28

Oct 28, 2011 ... For more resources and access to the GEM Practitioners Network, ... Home · Resources · Publications ... The Association for Progressive Communications Women's Networking Support Programme (APC WNSP) developed ...

Formation of GEMS from shock-accelerated crystalline dust in Superbubbles

International Nuclear Information System (INIS)

Westphal, A; Bradley, J P

2004-01-01

Interplanetary dust particles (IDPs) contain enigmatic sub-micron components called GEMS (Glass with Embedded Metal and Sulfides). The compositions and structures of GEMS indicate that they have been processed by exposure to ionizing radiation but details of the actual irradiation environment(s) have remained elusive. Here we propose a mechanism and astrophysical site for GEMS formation that explains for the first time the following key properties of GEMS; they are stoichiometrically enriched in oxygen and systematically depleted in S, Mg, Ca and Fe (relative to solar abundances), most have normal (solar) oxygen isotopic compositions, they exhibit a strikingly narrow size distribution (0.1-0.5 (micro)m diameter), and some of them contain ''relict'' crystals within their silicate glass matrices. We show that the compositions, size distribution, and survival of relict crystals are inconsistent with amorphization by particles accelerated by diffusive shock acceleration. Instead, we propose that GEMS are formed from crystalline grains that condense in stellar outflows from massive stars in OB associations, are accelerated in encounters with frequent supernova shocks inside the associated superbubble, and are implanted with atoms from the hot gas in the SB interior. We thus reverse the usual roles of target and projectile. Rather than being bombarded at rest by energetic ions, grains are accelerated and bombarded by a nearly monovelocity beam of atoms as viewed in their rest frame. Meyer, Drury and Ellison have proposed that galactic cosmic rays originate from ions sputtered from such accelerated dust grains. We suggest that GEMS are surviving members of a population of fast grains that constitute the long-sought source material for galactic cosmic rays. Thus, representatives of the GCR source material may have been awaiting discovery in cosmic dust labs for the last thirty years

Design of large size segmented GEM foils and Drift PCB for CBM MUCH

International Nuclear Information System (INIS)

Saini, J.; Dubey, A.K.; Chattopadhyay, S.

2016-01-01

Triple GEM (Gas Electron Multiplier), sector shaped detectors will be used for Muon tracking in the Compressed Baryonic Matter (CBM) experiment at Anti-proton Ion Research (FAIR) facility at Darmstadt, Germany. The sizes of the detectors modules in the Muon Chambers (MUCH) are of the order of 1 meter with active area of about 75cms. Progressive pad geometry is chosen for the readout from these detectors. In construction of these chambers, three GEM foils are stacked on top of each other in a 3/2/2/2 gap configuration. The GEM foils are double layered copper clad 50μm thin Kapton foil. Each GEM foil has millions of holes on it. Foils of large surface area are prone to damages due to discharges owing to the high capacitance of the foil. Hence, these foils have their top surfaces divided into segments of about 100 sq.cm. Further segmentation may be necessary when there are high rate requirements, as in the case of CBM. For the GEM foils of CBM MUCH, a 24 segment layout has been adopted. Short-circuit in any of the GEM-holes will make entire foil un-usable. To reduce such occurrences, segment to segment isolation using opto-coupler in series with the GEM-foil segments has been introduced. Hence, a novel design for GEM chamber drift-PCB and foils has been made. In this scheme, each segment is powered and controlled individually. At the same time, the design takes into account, the space constraints, not only in x-y plane, but also in the z, due to compact assembly of MUCH detector layers

Project W-420 Ventilation Stack Monitoring System Year 2000 Compliance Assessment Project Plan

International Nuclear Information System (INIS)

BUSSELL, J.H.

1999-01-01

This document contains a limited assessment of Year 2000 compliance for Project W-420. Additional information is provided as a road map to project documents and other references that may be used to verify Year 2000 compliance. This assessment describes the potential Year 2000 (Y2K) problems and describes the methods for achieving Y2K Compliance for Project W-420, Ventilation Stack Monitoring Systems Upgrades. The purpose of this assessment is to give an overview of the project. This document will not be updated and any dates contained in this document are estimates and may change. The project work scope includes upgrades to ventilation stacks and generic effluent monitoring systems (GEMS) at the 244-A Double Contained Receiver Tank (DCRT), the 244-BX DCRT, the 244-CR Vault, tanks 241-C-105 and 241-C-106, the 244-S DCRT, and the 244-TX DCRT. A detailed description of system dates, functions, interfaces, potential Y2K problems, and date resolutions can not be described since the project is in the definitive design phase, This assessment will describe the methods, protocols, and practices to ensure that equipment and systems do not have Y2K problems

The Gravity and Extreme Magnetism Small Explorer (GEMS)

Science.gov (United States)

Kallman, T. R.

2011-01-01

The Gravity and Extreme Magnetism Small Explorer (GEMS) was selected by NASA for flight in 2014 to make a sensitive search for X-ray polarization from a wide set of source classes, including stellar black holes, Seyfert galaxies and quasars, blazars, rotation and accretion-powered pulsars, magnetars, shell supernova remnants and pulsar wind nebulae. Among the primary scientific objectives are determining the effects of the spin of black holes and the geometry of supermassive black hole accretion, determining the configurations of the magnetic fields and the X-ray emission of magnetars, and determining the magnetic structure of the supernova shocks in which cosmic rays are accelerated. GEMS will observe 23 targets during a 16 month prime mission, in observations that will be able to reach predicted levels of polarization. The mission can be extended to provide a guest observer phase. The GEMS instrument has time projection chamber polarimeters with high 2-10 keV efficiency at the focus of thin foil mirrors. The 4.5 m focal length mirrors will be deployed on an extended boom. The spacecraft with the instrument is rotated with a period of about 10 minutes to enable measurement and correction of systematic errors. A small Bragg reflection soft X-ray experiment takes advantage of this rotation to obtain a measurement at 0.5 keV. The design of the GEMS instrument and the mission, the expected performance and the planned science program will be discussed.

Study on Physical Properties and Chemical Composition of Some Myanmar Gems

International Nuclear Information System (INIS)

Kyaw Myint Htoo; Tun Khin; Sein Htoon

2004-05-01

Physical properties of some Myanmar gems were studied by using refractometer, dichroscope, polariscope, SG test, UV test and microscope. Then, chemical composition were investigated by XRF-technique. After that, gem identification, evaluation, colour improvement were studied according to these physical properties and chemical composition

Synthesis and Biological Evaluation of Glycosidase Inhibitors: gem-Difluoromethylenated Nojirimycin Analogues

DEFF Research Database (Denmark)

Bols, Mikael; Wang, Ruo-Wen; Qiu, Xiao-Long

2006-01-01

In our ongoing program aimed at the design, synthesis, and biological evaluation of novel gem-difluoromethylenated glycosidase inhibitors, gem-4,4-difluoromethylenated iminosugars (5-9) were synthesized. The biological evaluation of these synthetic iminosugars showed that the gem....... It is proposed that the unprotonated iminosugar is the species preferably bound by beta-glucosidase, due to the lower pK(a) value of iminosugar 6 than of 1 or 36, leaving iminosugars 1 and 36 mostly protonated at pH 5.0, while iminosugar 6 is not. Iminosugar 6 also displayed good and selective inhibition of beta...

Gemcitabine-loaded albumin nanospheres (GEM-ANPs) inhibit PANC-1 cells in vitro and in vivo

Science.gov (United States)

Li, Ji; Di, Yang; Jin, Chen; Fu, Deliang; Yang, Feng; Jiang, Yongjian; Yao, Lie; Hao, Sijie; Wang, Xiaoyi; Subedi, Sabin; Ni, Quanxing

2013-04-01

With the development of nanotechnology, special attention has been given to the nanomaterial application in tumor treatment. Here, a modified desolvation-cross-linking method was successfully applied to fabricate gemcitabine-loaded albumin nanospheres (GEM-ANPs), with 110 and 406 nm of mean diameter, respectively. The aim of this study was to assess the drug distribution, side effects, and antitumor activity of GEM-ANPs in vivo. The metabolic viability and flow cytometry analysis revealed that both GEM-ANPs, especially 406-nm GEM-ANPs, could effectively inhibit the metabolism and proliferation and promote the apoptosis of human pancreatic carcinoma (PANC-1) in vitro. Intravenous injection of 406-nm GEM-ANPs exhibited a significant increase of gemcitabine in the pancreas, liver, and spleen of Sprague-Dawley rats ( p PANC-1-induced tumor mice, intravenous injection of 406-nm GEM-ANPs also could effectively reduce the tumor volume by comparison with free gemcitabine. With these findings, albumin nanosphere-loading approach might be efficacious to improve the antitumor activity of gemcitabine, and the efficacy is associated with the size of GEM-ANPs.

GEM-E3: A computable general equilibrium model applied for Switzerland

International Nuclear Information System (INIS)

Bahn, O.; Frei, C.

2000-01-01

The objectives of the European Research Project GEM-E3-ELITE, funded by the European Commission and coordinated by the Centre for European Economic Research (Germany), were to further develop the general equilibrium model GEM-E3 (Capros et al., 1995, 1997) and to conduct policy analysis through case studies. GEM-E3 is an applied general equilibrium model that analyses the macro-economy and its interaction with the energy system and the environment through the balancing of energy supply and demand, atmospheric emissions and pollution control, together with the fulfillment of overall equilibrium conditions. PSI's research objectives within GEM-E3-ELITE were to implement and apply GEM-E3 for Switzerland. The first objective required in particular the development of a Swiss database for each of GEM-E3 modules (economic module and environmental module). For the second objective, strategies to reduce CO 2 emissions were evaluated for Switzerland. In order to develop the economic, PSI collaborated with the Laboratory of Applied Economics (LEA) of the University of Geneva and the Laboratory of Energy Systems (LASEN) of the Federal Institute of Technology in Lausanne (EPFL). The Swiss Federal Statistical Office (SFSO) and the Institute for Business Cycle Research (KOF) of the Swiss Federal Institute of Technology (ETH Zurich) contributed also data. The Swiss environmental database consists mainly of an Energy Balance Table and of an Emission Coefficients Table. Both were designed using national and international official statistics. The Emission Coefficients Table is furthermore based on know-how of the PSI GaBE Project. Using GEM-E3 Switzerland, two strategies to reduce the Swiss CO 2 emissions were evaluated: a carbon tax ('tax only' strategy), and the combination of a carbon tax with the buying of CO 2 emission permits ('permits and tax' strategy). In the first strategy, Switzerland would impose the necessary carbon tax to achieve the reduction target, and use the tax

Investigations on Important Properties of the 10 cm x 10 cm GEM Prototype

CERN Document Server

Saenboonruang, Kiadtisak; Kulasri, Kittipong; Ritthirong, Anawat

2015-01-01

The Gas Electron Multiplier (GEM) detector is one of promising particle and radiation detectors that has been improved greatly from previous gas detectors. The improvement includes better spatial resolutions, higher detection rate capabilities, and flexibilities in designs. In particular, the 10 cm x 10 cm GEM prototype is designed and provided by the Gas Detectors Development group (GDD) at CERN, Switzerland. With its simplicity in operations and designs, while still maintaining high qualities, the GEM prototype is suitable for both start-up and advanced researches. This article aims to report the investigations on some important properties of the 10 cm x 10 cm GEM detector using current measurement and signal counting. Results have shown that gains of the GEM prototype exponentially increase as voltage supplied to the detector increases, while the detector reaches full efficiency (plateau region) when the voltage is greater than 4100 V. In terms of signal sharing between X and Y strips of the readout, X str...

Study of relevant parameters of GEM-based detectors

CERN Document Server

Croci, Gabriele; Sauli, Fabio; Ragazzi, S

2007-01-01

The Gas Electron Multiplier consist of a thin Kapton insulating (50 $\\mu$m) foil copper-clad on both sides and perforated by a high density, regular matrix of holes (around 100 per square millimeter). Typically the distance between holes (pitch) is 140 $\\mu$m and diameters of about 70 $\\mu$m. The mesh is realised by conventional photolitographic methods as used for the fabrication of multi-layer board. Upon application of a potential difference between the GEM electrodes, a high dipole field develops in the holes focusing the field lines between the drift electrode and the readout element. Electron drift along the channel and the charge is amplified by a factor that depends on the field density and the length of the channel. Owing to their excellent position resolution and rate capability GEM-based detector are very suitable to be used in different applications: from the high energy physics to the medical field. The GEM temporal and rate gain stability was studied and it was discovered that the gain variation...

Development, characterization and qualification of first GEM foils produced in India

Science.gov (United States)

Shah, Aashaq; Ahmed, Asar; Gola, Mohit; Sharma, Ram Krishna; Malhotra, Shivali; Kumar, Ashok; Naimuddin, Md.; Menon, Pradeep; Srinivasan, K.

2018-06-01

The increasing demand for Gas Electron Multiplier (GEM) foils has been driven by their application in many current and proposed high-energy physics experiments. Micropack, a Bengaluru-based company, has established and commercialized GEM foils for the first time in India. Micropack used the double-mask etching technique to successfully produce 10 cm × 10 cm GEM foil. In this paper, we report on the development as well as the geometrical and electrical properties of these foils, including the size uniformity of the holes and leakage current measurements. Our characterization studies show that the foils are of good quality and satisfy all the necessary quality control criteria.

The development of neutron detectors for the GEM instrument at ISIS

International Nuclear Information System (INIS)

Rhodes, N.J.; Johnson, M.W.; Schooneveld, E.M.

2001-01-01

GEM is a new General Materials diffractometer now being commissioned at ISIS. To meet its broad based scientific programme GEM requires a large area position sensitive detector which covers a wide range of scattering angles and exhibits a high neutron count rate stability. This paper discusses the design of a ZnS/ 6 Li fibre coupled detector array that meets the GEM requirements. Typical detector characteristics are documented together with the current status of the project. Two thirds of the detector array are operational and from the results obtained to date it is already obvious that the impact of this instrument on neutron scattering studies will be profound. (author)

The Forward GEM Tracker of STAR at RHIC

OpenAIRE

Simon, F.; Balewski, J.; Fatemi, R.; Hasell, D.; Kelsey, J.; Majka, R.; Page, B.; Plesko, M.; Underwood, D.; Smirnov, N.; Sowinski, J.; Spinka, H.; Surrow, B.; Visser, G.

2008-01-01

The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is in the process of designing and constructing a forward tracking system based on triple GEM technology. This upgrade is necessary to give STAR the capability to reconstruct and identify the charge sign of W bosons over an extended rapidity range through their leptonic decay mode into an electron (positron) and a neutrino. This will allow a detailed study of the flavor-separated spin str...

Graphics gems II

CERN Document Server

Arvo, James

1991-01-01

Graphics Gems II is a collection of articles shared by a diverse group of people that reflect ideas and approaches in graphics programming which can benefit other computer graphics programmers.This volume presents techniques for doing well-known graphics operations faster or easier. The book contains chapters devoted to topics on two-dimensional and three-dimensional geometry and algorithms, image processing, frame buffer techniques, and ray tracing techniques. The radiosity approach, matrix techniques, and numerical and programming techniques are likewise discussed.Graphics artists and comput

GEMs with Double Layred Micropattern Electrodes and their Applications

CERN Document Server

Di Mauro, A.; Nappi, E.; Oliveira, R.; Peskov, V.; Pietropaolo, F.; Picchi, P.

We have developed and tested several new designs of GEM detectors with micropattern electrodes manufactured by microelectronic technology. In one design, the inner layer of the detector electrode consists of thin metallic strips and the outer layer is made of a resistive grid manufactured by a screen printing technology. In other designs, the electrodes were made of metallic strips fed by HV via micro-resistors manufactured by a screen printing technology. Due to these features, the new detectors have several important advantages over conventional GEMs or ordinary thick GEMs. For example, the resistive grid (in the first design) and the screen printed resistors (in other designs) limited the current in case of discharges, making these detectors intrinsically spark-protected. We will here describe our tests with the photosensitive versions of these detectors (coated with CsI layers) and the efforts of implementing them in several applications. In particular, we will focus on our activity towards the ALICE RICH...

Modelling Chemical Equilibrium Partitioning with the GEMS-PSI Code

Energy Technology Data Exchange (ETDEWEB)

Kulik, D.; Berner, U.; Curti, E

2004-03-01

Sorption, co-precipitation and re-crystallisation are important retention processes for dissolved contaminants (radionuclides) migrating through the sub-surface. The retention of elements is usually measured by empirical partition coefficients (Kd), which vary in response to many factors: temperature, solid/liquid ratio, total contaminant loading, water composition, host-mineral composition, etc. The Kd values can be predicted for in-situ conditions from thermodynamic modelling of solid solution, aqueous solution or sorption equilibria, provided that stoichiometry, thermodynamic stability and mixing properties of the pure components are known (Example 1). Unknown thermodynamic properties can be retrieved from experimental Kd values using inverse modelling techniques (Example 2). An efficient, advanced tool for performing both tasks is the Gibbs Energy Minimization (GEM) approach, implemented in the user-friendly GEM-Selector (GEMS) program package, which includes the Nagra-PSI chemical thermodynamic database. The package is being further developed at PSI and used extensively in studies relating to nuclear waste disposal. (author)

Modelling Chemical Equilibrium Partitioning with the GEMS-PSI Code

International Nuclear Information System (INIS)

Kulik, D.; Berner, U.; Curti, E.

2004-01-01

Sorption, co-precipitation and re-crystallisation are important retention processes for dissolved contaminants (radionuclides) migrating through the sub-surface. The retention of elements is usually measured by empirical partition coefficients (Kd), which vary in response to many factors: temperature, solid/liquid ratio, total contaminant loading, water composition, host-mineral composition, etc. The Kd values can be predicted for in-situ conditions from thermodynamic modelling of solid solution, aqueous solution or sorption equilibria, provided that stoichiometry, thermodynamic stability and mixing properties of the pure components are known (Example 1). Unknown thermodynamic properties can be retrieved from experimental Kd values using inverse modelling techniques (Example 2). An efficient, advanced tool for performing both tasks is the Gibbs Energy Minimization (GEM) approach, implemented in the user-friendly GEM-Selector (GEMS) program package, which includes the Nagra-PSI chemical thermodynamic database. The package is being further developed at PSI and used extensively in studies relating to nuclear waste disposal. (author)

Is Kyoto Fatally Flawed? An Analysis with MacGEM

International Nuclear Information System (INIS)

Eyckmans, J.; Van Regemorter, D.; Van Steenberghe, V.

2002-06-01

In this paper we present some numerical simulations with the MacGEM model to evaluate the consequences of the recent Marrakesh agreements and the defection of the USA for the Kyoto Protocol. MacGEM is a global marginal abatement cost model for carbon emissions from fossil fuel use based on the GEM-E3-World general equilibrium. Nonparticipation of the USA causes the equilibrium carbon price in Annex B countries to fall by approximately 50% since an important share of permit demand falls out. Carbon sinks enhancement activities enable Parties to fulfil their reduction commitment at lower compliance costs and cause the equilibrium permit price to decrease by 40%. Finally, it is shown that the former Soviet Union and central European countries have substantial monopoly power in the Kyoto carbon permit market. We conclude that the recent accords have eroded completely the Kyoto Protocol's emission targets but that they have the merit to have saved the international climate change negotiation framework

Activity of CERN and LNF groups on large area GEM detectors

Energy Technology Data Exchange (ETDEWEB)

Alfonsi, M. [CERN, Geneva (Switzerland); Bencivenni, G. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Brock, I. [Physikalisches Institute der Universitat Bonn, Bonn (Germany); Cerioni, S. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Croci, G.; David, E. [CERN, Geneva (Switzerland); De Lucia, E. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); De Oliveira, R. [CERN, Geneva (Switzerland); De Robertis, G. [Sezione INFN di Bari, Bari (Italy); Domenici, D., E-mail: Danilo.Domenici@lnf.infn.i [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Duarte Pinto, S. [CERN, Geneva (Switzerland); Felici, G.; Gatta, M.; Jacewicz, M. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Loddo, F. [Sezione INFN di Bari, Bari (Italy); Morello, G. [Dipeartimento di Fisica Universita della Calabria e INFN, Cosenza (Italy); Pistilli, M. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Ranieri, A. [Sezione INFN di Bari, Bari (Italy); Ropelewski, L. [CERN, Geneva (Switzerland); Sauli, F. [TERA Foundation, Novara (Italy)

2010-05-21

We report on the activity of CERN and INFN-LNF groups on the development of large area GEM detectors. The two groups work together within the RD51 Collaboration, to aim at the development of Micro-pattern Gas detectors technologies. The vast request for large area foils by the GEM community has driven a change in the manufacturing procedure by the TS-DEM-PMT laboratory, needed to overcome the previous size limitation of 450x450mm{sup 2}. Now a single-mask technology is used allowing foils to be made as large as 450x2000mm{sup 2}. The limitation in the short size, due to the definite width of the raw material, can be overcome by splicing more foils together. A 10x10cm{sup 2} GEM detector with the new single-mask foil has been tested with X-rays and the results are shown. Possible future applications for large area GEM are the TOTEM experiment upgrade at CERN, and the KLOE-2 experiment at the Dafne {Phi}-factory in Frascati.

Activity of CERN and LNF groups on large area GEM detectors

International Nuclear Information System (INIS)

Alfonsi, M.; Bencivenni, G.; Brock, I.; Cerioni, S.; Croci, G.; David, E.; De Lucia, E.; De Oliveira, R.; De Robertis, G.; Domenici, D.; Duarte Pinto, S.; Felici, G.; Gatta, M.; Jacewicz, M.; Loddo, F.; Morello, G.; Pistilli, M.; Ranieri, A.; Ropelewski, L.; Sauli, F.

2010-01-01

We report on the activity of CERN and INFN-LNF groups on the development of large area GEM detectors. The two groups work together within the RD51 Collaboration, to aim at the development of Micro-pattern Gas detectors technologies. The vast request for large area foils by the GEM community has driven a change in the manufacturing procedure by the TS-DEM-PMT laboratory, needed to overcome the previous size limitation of 450x450mm 2 . Now a single-mask technology is used allowing foils to be made as large as 450x2000mm 2 . The limitation in the short size, due to the definite width of the raw material, can be overcome by splicing more foils together. A 10x10cm 2 GEM detector with the new single-mask foil has been tested with X-rays and the results are shown. Possible future applications for large area GEM are the TOTEM experiment upgrade at CERN, and the KLOE-2 experiment at the Dafne Φ-factory in Frascati.

arXiv GEM Foil Quality Assurance For The ALICE TPC Upgrade

CERN Document Server

INSPIRE-00019412; Hildén, Timo

2018-01-01

The ALICE (A Large Ion Collider Experiment) experiment at the Large Hadron Collider (LHC) at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC) of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2) the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC) –based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz). The new ReadOut Chamber (ROC) design is based on Gas Electron Multiplier (GEM) technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, nec...

Gaseous elemental mercury (GEM) fluxes over canopy of two typical subtropical forests in south China

Science.gov (United States)

Yu, Qian; Luo, Yao; Wang, Shuxiao; Wang, Zhiqi; Hao, Jiming; Duan, Lei

2018-01-01

Mercury (Hg) exchange between forests and the atmosphere plays an important role in global Hg cycling. The present estimate of global emission of Hg from natural source has large uncertainty, partly due to the lack of chronical and valid field data, particularly for terrestrial surfaces in China, the most important contributor to global atmospheric Hg. In this study, the micrometeorological method (MM) was used to continuously observe gaseous elemental mercury (GEM) fluxes over forest canopy at a mildly polluted site (Qianyanzhou, QYZ) and a moderately polluted site (Huitong, HT, near a large Hg mine) in subtropical south China for a full year from January to December in 2014. The GEM flux measurements over forest canopy in QYZ and HT showed net emission with annual average values of 6.67 and 0.30 ng m-2 h-1, respectively. Daily variations of GEM fluxes showed an increasing emission with the increasing air temperature and solar radiation in the daytime to a peak at 13:00, and decreasing emission thereafter, even as a GEM sink or balance at night. High temperature and low air Hg concentration resulted in the high Hg emission in summer. Low temperature in winter and Hg absorption by plant in spring resulted in low Hg emission, or even adsorption in the two seasons. GEM fluxes were positively correlated with air temperature, soil temperature, wind speed, and solar radiation, while it is negatively correlated with air humidity and atmospheric GEM concentration. The lower emission fluxes of GEM at the moderately polluted site (HT) when compared with that in the mildly polluted site (QYZ) may result from a much higher adsorption fluxes at night in spite of a similar or higher emission fluxes during daytime. This shows that the higher atmospheric GEM concentration at HT restricted the forest GEM emission. Great attention should be paid to forests as a crucial increasing Hg emission source with the decreasing atmospheric GEM concentration in polluted areas because of Hg

Development of a time projection chamber using gas electron multipliers (GEM-TPC)

International Nuclear Information System (INIS)

Oda, S.X.; Hamagaki, H.; Ozawa, K.; Inuzuka, M.; Sakaguchi, T.; Isobe, T.; Gunji, T.; Morino, Y.; Saito, S.; Yamaguchi, Y.L.; Sawada, S.; Yokkaichi, S.

2006-01-01

We developed a prototype time projection chamber using gas electron multipliers (GEM-TPC) for high energy heavy ion collision experiments. To investigate its performance, we conducted a beam test with three kinds of gases (Ar(90%)-CH 4 (10%), Ar(70%)-C 2 H 6 (30%) and CF 4 ). Detection efficiency of 99%, and spatial resolution of 79μm in the pad-row direction and 313μm in the drift direction were achieved. The test results show that the GEM-TPC meets the requirements for high energy heavy ion collision experiments. The configuration and performance of the GEM-TPC are described

Gallium Electromagnetic (GEM) Thrustor Concept and Design

Science.gov (United States)

Polzin, Kurt A.; Markusic, Thomas E.

2006-01-01

We describe the design of a new type of two-stage pulsed electromagnetic accelerator, the gallium electromagnetic (GEM) thruster. A schematic illustration of the GEM thruster concept is given in Fig. 1. In this concept, liquid gallium propellant is pumped into the first stage through a porous metal electrode using an electromagneticpump[l]. At a designated time, a pulsed discharge (approx.10-50 J) is initiated in the first stage, ablating the liquid gallium from the porous electrode surface and ejecting a dense thermal gallium plasma into the second state. The presence of the gallium plasma in the second stage serves to trigger the high-energy (approx.500 I), send-stage puke which provides the primary electromagnetic (j x B) acceleration.

Application of CMOS charge-sensitive preamplifier in triple-GEM detector

International Nuclear Information System (INIS)

Lai Yongfang; Li Jin; Chinese Academy of Sciences, Beijing; Deng Zhi; Li Yulan; Liu Yinong; Li Yuanjing

2006-01-01

Among the various micro-pattern gas detectors (MPGD) that are available, the gas electron multiplier (GEM) detector is an attractive gas detector that has been used in particle physics experiments. However the GEM detector usually needs thousands of preamplifier units for its large number of micro-pattern readout strips or pads, which leads to considerable difficulties and complexities for front end electronics (FEE). Nowadays, by making use of complementary metal-oxide semiconductor (CMOS)-based application specific integrated circuit (ASIC), it is feasible to integrate hundreds of preamplifier units and other signal process circuits in a small-sized chip, which can be bound to the readout strips or pads of a micro-pattern particle detector (MPPD). Therefore, CMOS ASIC may provide an ideal solution to the readout problem of MPPD. In this article, a triple GEM detector is constructed and one of its readout strips is connected to a CMOS charge-sensitive preamplifier chip. The chip was exposed to an 55 Fe source of 5.9 kev X-ray, and the amplitude spectrum of the chip was tested, and it was found that the energy resolution was approximately 27%, which indicates that the chip can be used in triple GEM detectors. (authors)

Uniformity studies in large area triple-GEM based detectors

Energy Technology Data Exchange (ETDEWEB)

Akl, M. Abi [Science Program, Texas A& M University at Qatar, PO Box 23874, Doha (Qatar); Bouhali, O., E-mail: othmane.bouhali@qatar.tamu.edu [Science Program, Texas A& M University at Qatar, PO Box 23874, Doha (Qatar); Qatar Computing Research Institute, Hamad Bin Khalifa University, PO Box 5825, Doha (Qatar); Castaneda, A.; Maghrbi, Y.; Mohamed, T. [Science Program, Texas A& M University at Qatar, PO Box 23874, Doha (Qatar)

2016-10-01

Gas Electron Multiplier (GEM) based detectors have been used in many applications since their introduction in 1997. Large areas, e.g. exceeding 30×30 cm{sup 2}, of GEM detectors are foreseen in future experiments which puts stringent requirements on the uniformity of response across the detection area. We investigate the effect of small variations of several parameters that could affect the uniformity. Parameters such as the anode pitch, the gas gap, the size and the shape of the holes are investigated. Simulation results are presented and compared to previous experimental data.

16 CFR 23.25 - Misuse of the word “gem.”

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Misuse of the word âgem.â 23.25 Section 23... JEWELRY, PRECIOUS METALS, AND PEWTER INDUSTRIES § 23.25 Misuse of the word “gem.” (a) It is unfair or deceptive to use the word “gem” to describe, identify, or refer to a ruby, sapphire, emerald, topaz, or...

Global Entrepreneurship Monitor - Canada Survey | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

Researchers will follow the Global Entrepreneurship Monitor (GEM) program ... The study will provide detailed information on entrepreneurship in Canada that is ... sector, public sector, and civil society organizations on development issues.

Studies on GEM modules for a Large Prototype TPC for the ILC

International Nuclear Information System (INIS)

Tsionou, Dimitra

2017-01-01

The International Linear Collider (ILC) is a future electron–positron collider with centre of mass energy of 500–1000 GeV. The International Large Detector (ILD) is one of two detector concepts at the ILC. Its high precision tracking system consists of Silicon sub-detectors and a Time Projection Chamber (TPC) equipped with micro-pattern gas detectors (MPGDs). Within the framework of the LCTPC collaboration, a Large Prototype (LP) TPC has been built as a demonstrator. This prototype has been equipped with Gas Electron Multiplier (GEM) modules and studied with electron beams of energies 1–6 GeV at the DESY test beam facility. The performance of the prototype detector and the extrapolation to the ILD TPC is presented here. In addition, ongoing optimisation studies and R&D activities in order to prepare the next GEM module iteration are discussed.

Studies on GEM modules for a Large Prototype TPC for the ILC

Energy Technology Data Exchange (ETDEWEB)

Tsionou, Dimitra, E-mail: dimitra.tsionou@desy.de

2017-02-11

The International Linear Collider (ILC) is a future electron–positron collider with centre of mass energy of 500–1000 GeV. The International Large Detector (ILD) is one of two detector concepts at the ILC. Its high precision tracking system consists of Silicon sub-detectors and a Time Projection Chamber (TPC) equipped with micro-pattern gas detectors (MPGDs). Within the framework of the LCTPC collaboration, a Large Prototype (LP) TPC has been built as a demonstrator. This prototype has been equipped with Gas Electron Multiplier (GEM) modules and studied with electron beams of energies 1–6 GeV at the DESY test beam facility. The performance of the prototype detector and the extrapolation to the ILD TPC is presented here. In addition, ongoing optimisation studies and R&D activities in order to prepare the next GEM module iteration are discussed.

Studies on GEM modules for a large prototype TPC for the ILC

International Nuclear Information System (INIS)

Tsionou, Dimitra

2016-12-01

The International Linear Collider (ILC) is a future electron-positron collider with centre of mass energy of 500-1000 GeV. The International Large Detector (ILD) is one of two detector concepts at the ILC. Its high precision tracking system consists of Silicon sub-detectors and a Time Projection Chamber (TPC) equipped with micro-pattern gas detectors (MPGDs). Within the framework of the LCTPC collaboration, a Large Prototype (LP) TPC has been built as a demonstrator. This prototype has been equipped with Gas Electron Multiplier (GEM) modules and studied with electron beams of energies 1-6 GeV at the DESY test beam facility. The performance of the prototype detector and the extrapolation to the ILD TPC is presented here. In addition, ongoing optimisation studies and R and D; activities in order to prepare the next GEM module iteration are discussed.

The GEM code. A simulation program for the evaporation and the fission process of an excited nucleus

Energy Technology Data Exchange (ETDEWEB)

Furihata, Shiori [Mitsubishi Research Institute Inc., Tokyo (Japan); Niita, Koji [Research Organization for Information Science and Technology, Tokai, Ibaraki (Japan); Meigo, Shin-ichiro; Ikeda, Yujiro; Maekawa, Fujio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-03-01

The GEM code is a simulation program which describes the de-excitation process of an excited nucleus, which is based on the Generalized Evaporation Model and the Atchison fission model. It has been shown that the combination of the Bertini intranuclear cascade model and GEM accurately predicts the cross sections of light fragments, such as Be produced from the proton-induced reactions. It has also been shown that the use of the reevaluated parameters in the Atchison model improves predictions of cross sections of fission fragments produced from the proton-induced reaction on Au. In this report, we present details and the usage of the GEM code. Furthermore, the results of benchmark calculations are shown by using the combination of the Bertini intranuclear cascade model and the GEM code (INC/GEM). Neutron spectra and isotope production cross sections from the reactions on various targets irradiated by protons are calculated with INC/GEM. Those results are compared with experimental data as well as the calculation results with LAHET. INC/GEM reproduces the experiments of double differential neutron emissions from the reaction on Al and Pb. The isotopic distributions for He, Li, and Be produced from the reaction on Ag are in good agreement with experimental data within 50%, although INC/GEM underestimates those of heavier nuclei than O. It is also shown that the predictions with INC/GEM for isotope production of light fragments, such as Li and Be, are better than those calculation with LAHET, particularly for heavy target. INC/GEM also gives better estimates of the cross sections of fission products than LAHET. (author)

Performance study of a GEM-TPC prototype using cosmic rays

International Nuclear Information System (INIS)

Li Yulan; Qi Huirong; Li Jin; Gao Yuanning; Li Yuanjing; Yang Zhenwei; Fujii, Keisuke; Matsuda, Takeshi

2008-01-01

Time projection chambers (TPCs) have been successfully used as the central tracking devices in a number of high-energy physics experiments. However, the performance requirements on TPCs for future high-energy physics experiments greatly exceed the abilities of traditional TPCs read out by multi-wire proportional chambers (MWPCs). Micro-pattern gas detectors (MPGDs), such as gas electron multipliers (GEMs) or micromegas, have great potential to improve TPC performance when used as readout detectors. In order to evaluate its feasibility, a GEM-based TPC prototype with a drift length up to 50 cm was designed. Measurements of the spatial resolution of cosmic-ray tracks without and with a magnetic field (B=1 T) are presented. A very good performance is achieved, matching the analytic formula for the spatial resolution of a MPGD-readout TPC. A dedicated study shows that the increase of GEM detector gain can improve the TPC's spatial resolution.

Gaseous elemental mercury (GEM fluxes over canopy of two typical subtropical forests in south China

Directory of Open Access Journals (Sweden)

Q. Yu

2018-01-01

Full Text Available Mercury (Hg exchange between forests and the atmosphere plays an important role in global Hg cycling. The present estimate of global emission of Hg from natural source has large uncertainty, partly due to the lack of chronical and valid field data, particularly for terrestrial surfaces in China, the most important contributor to global atmospheric Hg. In this study, the micrometeorological method (MM was used to continuously observe gaseous elemental mercury (GEM fluxes over forest canopy at a mildly polluted site (Qianyanzhou, QYZ and a moderately polluted site (Huitong, HT, near a large Hg mine in subtropical south China for a full year from January to December in 2014. The GEM flux measurements over forest canopy in QYZ and HT showed net emission with annual average values of 6.67 and 0.30 ng m−2 h−1, respectively. Daily variations of GEM fluxes showed an increasing emission with the increasing air temperature and solar radiation in the daytime to a peak at 13:00, and decreasing emission thereafter, even as a GEM sink or balance at night. High temperature and low air Hg concentration resulted in the high Hg emission in summer. Low temperature in winter and Hg absorption by plant in spring resulted in low Hg emission, or even adsorption in the two seasons. GEM fluxes were positively correlated with air temperature, soil temperature, wind speed, and solar radiation, while it is negatively correlated with air humidity and atmospheric GEM concentration. The lower emission fluxes of GEM at the moderately polluted site (HT when compared with that in the mildly polluted site (QYZ may result from a much higher adsorption fluxes at night in spite of a similar or higher emission fluxes during daytime. This shows that the higher atmospheric GEM concentration at HT restricted the forest GEM emission. Great attention should be paid to forests as a crucial increasing Hg emission source with the decreasing atmospheric GEM concentration

Discriminating cosmic muons and X-rays based on rise time using a GEM detector

Science.gov (United States)

Wu, Hui-Yin; Zhao, Sheng-Ying; Wang, Xiao-Dong; Zhang, Xian-Ming; Qi, Hui-Rong; Zhang, Wei; Wu, Ke-Yan; Hu, Bi-Tao; Zhang, Yi

2016-08-01

Gas electron multiplier (GEM) detectors have been used in cosmic muon scattering tomography and neutron imaging over the last decade. In this work, a triple GEM device with an effective readout area of 10 cm × 10 cm is developed, and a method of discriminating between cosmic muons and X-rays based on rise time is tested. The energy resolution of the GEM detector is tested by 55Fe ray source to prove the GEM detector has a good performance. Analysis of the complete signal-cycles allows us to get the rise time and pulse heights. The experiment result indicates that cosmic muons and X-rays can be discriminated with an appropriate rise time threshold. Supported by National Natural Science Foundation of China (11135002, 11275235, 11405077, 11575073)

GEM-E3: A computable general equilibrium model applied for Switzerland

Energy Technology Data Exchange (ETDEWEB)

Bahn, O. [Paul Scherrer Inst., CH-5232 Villigen PSI (Switzerland); Frei, C. [Ecole Polytechnique Federale de Lausanne (EPFL) and Paul Scherrer Inst. (Switzerland)

2000-01-01

The objectives of the European Research Project GEM-E3-ELITE, funded by the European Commission and coordinated by the Centre for European Economic Research (Germany), were to further develop the general equilibrium model GEM-E3 (Capros et al., 1995, 1997) and to conduct policy analysis through case studies. GEM-E3 is an applied general equilibrium model that analyses the macro-economy and its interaction with the energy system and the environment through the balancing of energy supply and demand, atmospheric emissions and pollution control, together with the fulfillment of overall equilibrium conditions. PSI's research objectives within GEM-E3-ELITE were to implement and apply GEM-E3 for Switzerland. The first objective required in particular the development of a Swiss database for each of GEM-E3 modules (economic module and environmental module). For the second objective, strategies to reduce CO{sub 2} emissions were evaluated for Switzerland. In order to develop the economic, PSI collaborated with the Laboratory of Applied Economics (LEA) of the University of Geneva and the Laboratory of Energy Systems (LASEN) of the Federal Institute of Technology in Lausanne (EPFL). The Swiss Federal Statistical Office (SFSO) and the Institute for Business Cycle Research (KOF) of the Swiss Federal Institute of Technology (ETH Zurich) contributed also data. The Swiss environmental database consists mainly of an Energy Balance Table and of an Emission Coefficients Table. Both were designed using national and international official statistics. The Emission Coefficients Table is furthermore based on know-how of the PSI GaBE Project. Using GEM-E3 Switzerland, two strategies to reduce the Swiss CO{sub 2} emissions were evaluated: a carbon tax ('tax only' strategy), and the combination of a carbon tax with the buying of CO{sub 2} emission permits ('permits and tax' strategy). In the first strategy, Switzerland would impose the necessary carbon tax to achieve

A refined gravity model from Lageos /GEM-L2/

Science.gov (United States)

Lerch, F. J.; Klosko, S. M.; Patel, G. B.

1982-01-01

Lageos satellite laser ranging (SLR) data taken over a 2.5 yr period were employed to develop the Goddard Earth Model GEM-L2, a refined gravity field model. Additional data was gathered with 30 other satellites, resulting in spherical harmonics through degree and order 20, based on over 600,000 measurements. The Lageos data was accurate down to 10 cm, after which the GEM 9 data were used to make adjustments past order 7. The resolution of long wavelength activity, through degree and order 4, was made possible by the Lageos data. The GEM-L2 model features a 20 x 20 geopotential, tracking station coordinates (20), 5-day polar motion and A1-UT1 values, and a GM value of 398,600.607 cu km/sq sec. The accuracy of station positioning has been raised to within 6 cm total position globally and within 1.8 cm in baselines. It is concluded that SLR is useful for measuring tectonic plate motions and inter-plate deformations.

The TOTEM GEM Telescope (T2) at the LHC

International Nuclear Information System (INIS)

Quinto, M.; Berretti, M.; David, E.; Garcia, F.; Greco, V.; Heino, J.; Hilden, T.; Kurvinen, K.; Lami, S.; Latino, G.; Lauhakangas, R.; Oliveri, E.; Ropelewski, L.; Scribano, A.; Turini, N.; Stenis, M. van

2011-01-01

The TOTEM T2 telescope will measure inelastically produced charged particles in the forward region of the LHC Interaction Point 5. Each arm of the telescope consists in a set of 20 triple-GEM (Gas Electron Multiplier) detectors with tracking and trigger capabilities. The GEM technology has been considered for the design of TOTEM very forward T2 telescopes thanks to its characteristics: large active areas, good position and timing resolution, excellent rate capability and radiation hardness. Each of the four T2 half arms has been fully assembled and equipped with electronics at CERN and systematically tested in the SPS beam line H8 in 2008/09. After some optimization, the operation of the GEM chambers was fully satisfactory and the T2 telescopes were installed and commissioned in their final positions at the LHC interaction point. During the first LHC run (December 2009) the T2 telescopes have collected data, at 900 GeV and 2.36 TeV. We will present here the performances of the detector and the preliminary results obtained using the data collected.

The TOTEM GEM Telescope (T2) at the LHC

Energy Technology Data Exchange (ETDEWEB)

Quinto, M. [INFN Sezione di Bari, Via E.Orabona n 4, 70126 Bari (Italy); Berretti, M. [University of Siena, Physics Department, Via Roma 56, I-53100 Siena (Italy); INFN Sezione di Pisa, Largo B. Pontecorvo, 3. I-56127. Pisa (Italy); David, E. [CERN, PH Department, 1211 Geneva 23, Geneva (Switzerland); Garcia, F. [University of Helsinki, Institute of Physics and Department of Physical Sciences, Helsinki (Finland); Greco, V. [University of Siena, Physics Department, Via Roma 56, I-53100 Siena (Italy); INFN Sezione di Pisa, Largo B. Pontecorvo, 3. I-56127. Pisa (Italy); Heino, J.; Hilden, T.; Kurvinen, K. [University of Helsinki, Institute of Physics and Department of Physical Sciences, Helsinki (Finland); Lami, S. [INFN Sezione di Pisa, Largo B. Pontecorvo, 3. I-56127. Pisa (Italy); Latino, G. [University of Siena, Physics Department, Via Roma 56, I-53100 Siena (Italy); INFN Sezione di Pisa, Largo B. Pontecorvo, 3. I-56127. Pisa (Italy); Lauhakangas, R. [University of Helsinki, Institute of Physics and Department of Physical Sciences, Helsinki (Finland); Oliveri, E. [University of Siena, Physics Department, Via Roma 56, I-53100 Siena (Italy); INFN Sezione di Pisa, Largo B. Pontecorvo, 3. I-56127. Pisa (Italy); Ropelewski, L. [CERN, PH Department, 1211 Geneva 23, Geneva (Switzerland); Scribano, A.; Turini, N. [University of Siena, Physics Department, Via Roma 56, I-53100 Siena (Italy); INFN Sezione di Pisa, Largo B. Pontecorvo, 3. I-56127. Pisa (Italy); Stenis, M. van [CERN, PH Department, 1211 Geneva 23, Geneva (Switzerland)

2011-06-15

The TOTEM T2 telescope will measure inelastically produced charged particles in the forward region of the LHC Interaction Point 5. Each arm of the telescope consists in a set of 20 triple-GEM (Gas Electron Multiplier) detectors with tracking and trigger capabilities. The GEM technology has been considered for the design of TOTEM very forward T2 telescopes thanks to its characteristics: large active areas, good position and timing resolution, excellent rate capability and radiation hardness. Each of the four T2 half arms has been fully assembled and equipped with electronics at CERN and systematically tested in the SPS beam line H8 in 2008/09. After some optimization, the operation of the GEM chambers was fully satisfactory and the T2 telescopes were installed and commissioned in their final positions at the LHC interaction point. During the first LHC run (December 2009) the T2 telescopes have collected data, at 900 GeV and 2.36 TeV. We will present here the performances of the detector and the preliminary results obtained using the data collected.

Gravity model improvement using GEOS 3 /GEM 9 and 10/. [and Seasat altimetry data

Science.gov (United States)

Lerch, F. J.; Wagner, C. A.; Klosko, S. M.; Laubscher, R. E.

1979-01-01

Although errors in previous gravity models have produced large uncertainties in the orbital position of GEOS 3, significant improvement has been obtained with new geopotential solutions, Goddard Earth Model (GEM) 9 and 10. The GEM 9 and 10 solutions for the potential coefficients and station coordinates are presented along with a discussion of the new techniques employed. Also presented and discussed are solutions for three fundamental geodetic reference parameters, viz. the mean radius of the earth, the gravitational constant, and mean equatorial gravity. Evaluation of the gravity field is examined together with evaluation of GEM 9 and 10 for orbit determination accuracy. The major objectives of GEM 9 and 10 are achieved. GEOS 3 orbital accuracies from these models are about 1 m in their radial components for 5-day arc lengths. Both models yield significantly improved results over GEM solutions when compared to surface gravimetry, Skylab and GEOS 3 altimetry, and highly accurate BE-C (Beacon Explorer-C) laser ranges. The new values of the parameters discussed are given.

Characterization of the allergen Sol gem 2 from the fire ant venom, Solenopsis geminata

Directory of Open Access Journals (Sweden)

S Sukprasert

2012-01-01

Full Text Available Sol i 2 is a potent allergen in Solenopsis invicta venom, and most humans exhibit reactivity to it. The Sol gem 2 allergen found in the venom of the Thai tropical fire ant Solenopsis geminata was analysed in the present study. The protein was present in higher amounts than other proteins, as determined by SDS-PAGE, and presumably has allergenic properties similar to those of Sol i 2. Sol gem 2 molecular weight is 28 and 15 kDa, respectively, under non-reducing and reducing conditions, indicating that its native form is a dimer. LC-MS/MS analysis confirmed its similarity to Sol i 2. The mono/dimeric form of Sol gem 2 was determined to be relevant by proteomic approach and immunoblotting. An anti-Sol gem 2 antibody was produced in mice, with a titer greater than 1:800 according to the Western blotting analysis. The Sol gem 2-neutralising activity of this antibody was determined in crickets. The paralytic dose 50 (PD50 of crude S. geminata venom was elevated from 0.18 mg/g of body weight to more than 0.90 mg/g of body weight after preincubation with antibody at a ratio of 1:1. These results suggest that Sol gem 2 plays an important role in mediating the effects of the piperidine derivatives in the venom.

Gas Gain Measurement Of GEM-Foil In Argon-Carbon Dioxide Mixture

International Nuclear Information System (INIS)

Nguyen Ngoc Duy; Vuong Huu Tan; Le Hong Khiem

2011-01-01

Nuclear reaction measurement with radioactive beam at low energy plays an important role in nuclear astrophysics and nuclear structure. The trajectory of particle beams can be obtained by using an active gas target, multiple-sampling and tracking proportional chamber (MSTPC), as a proportional counter. Because of intensity of low energy radioactive beam, in the stellar reaction such as (α, p), (p, α), it is necessary to increase the gain for the counter. In this case, a gas electrons multiplier (GEM) foil will be used, so the proportional counter is called GEM-MSTPC. The efficient gas gain of GEM foils which relates to foil thickness and operating pressure was investigated with two type of the foils, 400 μm and 200 μm, in Argon (70%) + Carbon dioxide (30%) mixture. (author)

Wits Post Graduate Symposium Poster - iGEM

CSIR Research Space (South Africa)

Millroy, L

2010-08-01

Full Text Available This document is a poster providing details of the 2010 International Genetically Engineered Machines (iGEM) competition. The origins of the competition, as well as criteria, judging, sponsors, topic and team, are briefly described....

Studies of characteristics of triple GEM detector for the ALICE-TPC upgrade

International Nuclear Information System (INIS)

Patra, Rajendra Nath; Singaraju, R.N.; Ahammed, Z.; Nayak, T.K.; Biswas, S.

2015-01-01

Gas Electron Multiplier (GEM) is a novel gas detector in the field of radiation detection. GEM detectors have tremendous advantages over other types gas detectors like high rate handling capability with high efficiency and very low ion back flow (IBF). These detectors are most suitable for the use in the future experiments in high-energy proton-proton and heavy-ion collisions at the Large Hadron Collider (LHC) at CERN and Facility for Antiproton and Ion Research (FAIR) at GSI. A Large Ion Collider Experiment (ALICE) at the LHC is a dedicated experiment for the study of Quark Gluon Plasma (QGP). In few years, the data taking rate for Pb-Pb collisions will increase by 100 times to 50 KHz. The ALICE Time Projection Chamber (TPC) is the main tracking detector in ALICE. It is planned that by the year 2018, GEM detectors will replace the present readout planes of TPC. The goal of the present study is to characterize the GEM detector to achieve the performance goal of the TPC

Fiber Bragg Grating sensors for deformation monitoring of GEM foils in HEP detectors

CERN Document Server

AUTHOR|(CDS)2071648; Bianco, S; Caponero, M; Muhammad, S; Passamonti, L; Piccolo, D; Pierluigi, D; Raffone, G; Russo, A; Saviano, G

2015-01-01

Fiber Bragg Grating (FBG) sensors have been so far mainly used in high energy physics (HEP) as high precision positioning and re-positioning sensors and as low cost, easy to mount, radiation hard and low space- consuming temperature and humidity devices. FBGs are also commonly used for very precise strain measurements. In this work we present a novel use of FBGs as flatness and mechanical tensioning sensors applied to the wide Gas Electron Multiplier (GEM) foils of the GE1/1 chambers of the Compact Muon Solenoid (CMS) experiment at Large Hadron Collider (LHC) of CERN. A network of FBG sensors has been used to determine the optimal mechanical tension applied and to characterize the mechanical stress applied to the foils. The preliminary results of the test performed on a full size GE1/1 final prototype and possible future developments will be discussed.

A new Slow Control and Run Initialization Byte-wise Environment (SCRIBE) for the quality control of mass-produced CMS GEM detectors

CERN Document Server

Colafranceschi, Stefano

2016-01-01

The CMS collaboration aims at improving the muon trigger and tracking performance at the HL-LHC by installing new Gas Electron Multiplier (GEM) detectors in the endcaps of the CMS experiment. Construction and commissioning of GEM detectors for the first muon endcap stations is ramping up in several laboratories using common quality control protocols. The SCRIBE framework is a scalable and cross-platform web-based application for the RD51 Scalable Readout System (SRS) that controls data acquisition and analyzes data in near real time. It has been developed mainly to simplify and standardize measurements of the GEM detector response uniformities with x-rays across all production sites. SCRIBE works with zero suppression of raw SRS pulse height data. This has increased acquisition rates to 5 kHz for a CMS GEM detector with 3072 strips and allows strip-by-strip response comparisons with a few hours of data taking. SCRIBE also manages parallel data reconstruction to provide near real-time feedback on the detector ...

Metal-mediated gem-Difluoroallylation of N-Acylhydrazones: Highly Efficient Synthesis of a,a-Difluorohomoallylic Amines

Institute of Scientific and Technical Information of China (English)

YUE Xuyi; QIU Xiaolong; QING Fengling

2009-01-01

Indium-mediated gem-difluoroallylation of aldehyde-derived N-acylhydrazones 1a-1q and 4a-4g with 3-bromo-3,3-difluoropropene 2 afforded a,a-difluorohomoallylic hydrazides 3a-3q and 5a-5g in high yields, re-spectively. Functional groups such as nitro, phenolic hydroxyl, benzyloxy and even C=C bonds of a,fl-unsaturated aldehydes were compatible under this mild and operationally simple gem-difluoroallylic reaction condition. By means of substitution of Zn powder for indium, gem-difluoroallylation of ketone-derived N-acylhydrazones 6a-6d also provided the corresponding a,a-difluorohomoallylic hydrazides 7a-7d in medium yields. The N-N bond cleavage of the hydrazide 3a proceeded smoothly to give the corresponding primary gem-difluorohomoallylic amine 8, which could be converted to gem-difluoro-δ-substituted α,β-unsaturated lactam 11 via acryloylation fol-lowed by ring closing metathesis (RCM) reaction.

Empirical CPU power modelling and estimation in the gem5 simulator

OpenAIRE

Basireddy, Karunakar Reddy; Walker, Matthew; Balsamo, Domenico; Diestelhorst, Stephan; Al-Hashimi, Bashir; Merrett, Geoffrey

2017-01-01

Power modelling is important for modern CPUs to inform power management approaches and allow design space exploration. Power simulators, combined with a full-system architectural simulator such as gem5, enable power-performance trade-offs to be investigated early in the design of a system with different configurations (e.g number of cores, cache size, etc.). However, the accuracy of existing power simulators, such as McPAT, is known to be low due to the abstraction and specification errors, a...

Screening the Drug Sensitivity Genes Related to GEM and CDDP in the Lung Cancer Cell-lines

Directory of Open Access Journals (Sweden)

Chunyu YANG

2009-10-01

Full Text Available Background and objective Screening of small-cell lung cancer (SCLC and non-small cell lung cancer (NSCLC cell lines with gemcitabine hydrochloride (GEM and cisplatin (CDDP related to drug sensitivity gene might clarify the action mechanism of anti-cancer drugs and provide a new clue for overcoming drug resistance and the development of new anti-cancer drugs, and also provide theoretical basis for the clinical treatment of individual. Methods The drug sensitivity of CDDP and GEM in 4 SCLC cell lines and 6 NSCLC cell lines was determined using MTT colorimetric assay, while the cDNA macroarray was applied to detect the gene expression state related to drug sensitivity of 10 lung cancer cell line in 1 291, and the correlation between the two was analysized. Results There were 6 genes showing significant positive correlation (r≥0.632, P < 0.05 with GEM sensitivity; 45 genes positively related to CDDP; another 41 genes related to both GEM and CDDP (r≥± 0.4. Lung cancer with GEM and CDDP sensitivity of two types of drugs significantly related genes were Metallothinein (Signal transduction molecules, Cathepsin B (Organization protease B and TIMP1 (Growth factor; the GEM, CDDP sensitivity associated genes of lung cancer cell lines mainly distributed in Metallothinein, Cathepsin B, growth factor TIMP1 categories. Conclusion There existed drug-related sensitive genes of GEM, CDDP in SCLC and NSCLC cell lines; of these genes, Metallothinein, Cathepsin B and TIMP1 genes presented a significant positive correlation with GEM drug sensitivity, a significant negative correlation with CDDP drug sensitivity.

SYNTHESIS AND POLYMERIZATION OF GEM-METHYL(VINYLBENZYL)TETRACHLOROCYCLOTRIPHOSPHAZENE

NARCIS (Netherlands)

BOSSCHER, G; VANDEGRAMPEL, JC

A new styrene-substituted chlorocyclotriphosphazene, gem-methyl(vinylbenzyl) tetrachlorocyclotriphosphazene, has been prepared from vinylbenzylmagnesium chloride and hexachlorocyclotriphosphazene. The organosubstituted chlorocyclotriphosphazene has been used in radical homo- and copolymerization

Analysis of unscrammed loss of flow and heat sink for PRISM with GEM

International Nuclear Information System (INIS)

Slovik, G.C.; Van Tuyle, G.J.; Kennett, R.J.

1991-01-01

The US Department of Energy is sponsoring an advanced liquid-metal reactor design by General Electric Company (GE) called PRISM. The intent is to design a reactor with passively safe responses to many operational and severe accidents. PRISM is under review at the US Nuclear Regulatory Commission for licensability with Brookhaven National Laboratory providing technical assistance. Recently, the PRISM design has been modified to include three gas expansion modules (GEMs) on its core periphery. The GEMs were added to quickly reduce the power (by inserting negative reactivity) during loss-of-flow events to curtail peak fuel and clad temperatures predicted in the previous design. The GEM prototypes have been tested at the Fast Flux Test Facility. The significance of the GEMs in PRISM is discussed in this paper through the evaluation of the unprotected loss of flow (ULOF) and loss of heat sink using the SSC code. It has been demonstrated in the past that SSC predicts results similar to GE and other liquid-metal reactor codes

MeerLICHT and BlackGEM: custom-built telescopes to detect faint optical transients

Science.gov (United States)

Bloemen, Steven; Groot, Paul; Woudt, Patrick; Klein Wolt, Marc; McBride, Vanessa; Nelemans, Gijs; Körding, Elmar; Pretorius, Margaretha L.; Roelfsema, Ronald; Bettonvil, Felix; Balster, Harry; Bakker, Roy; Dolron, Peter; van Elteren, Arjen; Elswijk, Eddy; Engels, Arno; Fender, Rob; Fokker, Marc; de Haan, Menno; Hagoort, Klaas; de Hoog, Jasper; ter Horst, Rik; van der Kevie, Giel; Kozłowski, Stanisław; Kragt, Jan; Lech, Grzegorz; Le Poole, Rudolf; Lesman, Dirk; Morren, Johan; Navarro, Ramon; Paalberends, Willem-Jelle; Paterson, Kerry; Pawłaszek, Rafal; Pessemier, Wim; Raskin, Gert; Rutten, Harrie; Scheers, Bart; Schuil, Menno; Sybilski, Piotr W.

2016-07-01

We present the MeerLICHT and BlackGEM telescopes, which are wide-field optical telescopes that are currently being built to study transient phenomena, gravitational wave counterparts and variable stars. The telescopes have 65 cm primary mirrors and a 2.7 square degree field-of-view. The MeerLICHT and BlackGEM projects have different science goals, but will use identical telescopes. The first telescope, MeerLICHT, will be commissioned at Sutherland (South Africa) in the first quarter of 2017. It will co-point with MeerKAT to collect optical data commensurate with the radio observations. After careful analysis of MeerLICHT's performance, three telescopes of the same type will be commissioned in La Silla (Chile) in 2018 to form phase I of the BlackGEM array. BlackGEM aims at detecting and characterizing optical counterparts of gravitational wave events detected by Advanced LIGO and Virgo. In this contribution we present an overview of the science goals, the design and the status of the two projects.

Development of triple GEM detector for a heavy ion physics experiment

International Nuclear Information System (INIS)

Bhardwaj, A.; Biswal, K.; Gupta, R.

2015-01-01

Building and testing of micro-pattern gas detector such as Gas Electron Multiplier (GEM) for several upcoming High-Energy Physics (HEP) experiment projects, is an advance area of research in the field of detector development. We have carried out the long-term stability test and the uniformity of the relative gain over a GEM detector. The method of long-term test and uniformity of the relative gain and the results are presented in this article

lumpGEM: Systematic generation of subnetworks and elementally balanced lumped reactions for the biosynthesis of target metabolites.

Directory of Open Access Journals (Sweden)

Meric Ataman

2017-07-01

Full Text Available In the post-genomic era, Genome-scale metabolic networks (GEMs have emerged as invaluable tools to understand metabolic capabilities of organisms. Different parts of these metabolic networks are defined as subsystems/pathways, which are sets of functional roles to implement a specific biological process or structural complex, such as glycolysis and TCA cycle. Subsystem/pathway definition is also employed to delineate the biosynthetic routes that produce biomass building blocks. In databases, such as MetaCyc and SEED, these representations are composed of linear routes from precursors to target biomass building blocks. However, this approach cannot capture the nested, complex nature of GEMs. Here we implemented an algorithm, lumpGEM, which generates biosynthetic subnetworks composed of reactions that can synthesize a target metabolite from a set of defined core precursor metabolites. lumpGEM captures balanced subnetworks, which account for the fate of all metabolites along the synthesis routes, thus encapsulating reactions from various subsystems/pathways to balance these metabolites in the metabolic network. Moreover, lumpGEM collapses these subnetworks into elementally balanced lumped reactions that specify the cost of all precursor metabolites and cofactors. It also generates alternative subnetworks and lumped reactions for the same metabolite, accounting for the flexibility of organisms. lumpGEM is applicable to any GEM and any target metabolite defined in the network. Lumped reactions generated by lumpGEM can be also used to generate properly balanced reduced core metabolic models.

La Gemäldegalerie di Dresda. Evoluzione dal Settecento a fine Ottocento

Directory of Open Access Journals (Sweden)

Aloisia Marzotto Caotorta

2015-12-01

Full Text Available Since its foundation, the Gemäldegalerie (Old Masters Picture Gallery in Dresden has been considered one of the most magnificent picture galleries in Europe. Not only during the Augustan Age there was a keen interest in the arts, but also a strong understanding of the arts as a means of political power claims. In this context, the Gemäldegalerie was the most representative display of this phenomenon. This article aims to explore the complex role played by the galleries of royal and aristocratic residences in Saxony, concentrating on the Gemäldegalerie between the 18th and 19th centuries as a case study, as well as focusing on its impact on contemporary German literature.

The development and evaluation of mini-GEMs - short, focused, online e-learning videos in geriatric medicine.

Science.gov (United States)

Garside, Mark J; Fisher, James M; Blundell, Adrian G; Gordon, Adam L

2018-01-01

Mini Geriatric E-Learning Modules (Mini-GEMs) are short, focused, e-learning videos on geriatric medicine topics, hosted on YouTube, which are targeted at junior doctors working with older people. This study aimed to explore how these resources are accessed and used. The authors analyzed the viewing data from 22 videos published over the first 18 months of the Mini-GEM project. We conducted a focus group of U.K. junior doctors considering their experiences with Mini-GEMS. The Mini-GEMs were viewed 10,291 times over 18 months, equating to 38,435 minutes of total viewing time. The average viewing time for each video was 3.85 minutes. Learners valued the brevity and focused nature of the Mini-GEMs and reported that they watched them in a variety of settings to supplement clinical experiences and consolidate learning. Watching the videos led to an increase in self-reported confidence in managing older patients. Mini-GEMs can effectively disseminate clinical teaching material to a wide audience. The videos are valued by junior doctors due to their accessibility and ease of use.

The TOTEM T2 telescope based on triple-GEM chambers

CERN Document Server

Bagliesi, M G; Brucken, E; Cecchi, R; David, E; Garcia, F; Greco, V; Heino, J; Hilden, T; Kurvinen, K; Lauhakangas, R; Lami, S; Latino, G; Magazzu, G; Oliveri, E; Pedreschi, E; Ropelewski, L; Scribano, A; Spinella, F; Turini, N; van Stenis, M

2010-01-01

The TOTEM experiment at LHC has chosen the triple Gas Electron Multiplier (GEM) technology for its T2 telescope which will provide charged track reconstruction in the pseudorapidity range 5.3<|η|<6.5 and a fully inclusive trigger for inelastic events. GEMs are gas filled detectors which combine good spatial resolution with very high rate capability and a good resistance to radiation. Preliminary results of cosmic ray tests performed at CERN on final T2 modules before installation are here presented. Comparisons between real and simulated detector performance are also shown.

The TOTEM T2 telescope based on triple-GEM chambers

Energy Technology Data Exchange (ETDEWEB)

Bagliesi, M.G., E-mail: mg.bagliesi@pi.infn.i [University of Siena and INFN Pisa (Italy); Berretti, M. [University of Siena and INFN Pisa (Italy); Brucken, E. [Helsinki (Finland); Cecchi, R. [University of Siena and INFN Pisa (Italy); David, E. [CERN, Geneva (Switzerland); Garcia, F. [Helsinki (Finland); Greco, V. [University of Siena and INFN Pisa (Italy); Heino, J.; Hilden, T.; Kurvinen, K.; Lauhakangas, R. [Helsinki (Finland); Lami, S.; Latino, G.; Magazzu, G.; Oliveri, E.; Pedreschi, E. [University of Siena and INFN Pisa (Italy); Ropelewski, L. [CERN, Geneva (Switzerland); Scribano, A.; Spinella, F.; Turini, N. [University of Siena and INFN Pisa (Italy)

2010-05-21

The TOTEM experiment at LHC has chosen the triple Gas Electron Multiplier (GEM) technology for its T2 telescope which will provide charged track reconstruction in the pseudorapidity range 5.3<|{eta}|<6.5 and a fully inclusive trigger for inelastic events. GEMs are gas filled detectors which combine good spatial resolution with very high rate capability and a good resistance to radiation. Preliminary results of cosmic ray tests performed at CERN on final T2 modules before installation are here presented. Comparisons between real and simulated detector performance are also shown.

Proceedings of the GEM Collaboration Meeting

International Nuclear Information System (INIS)

Bojowald, J.; Ilieva, I.; Klimala, W.; Machner, H.; Razen, B.; Kliczewski, S.; Magiera, A.; Smyrski, J.; Roy, B.J.; Urban, J.

1997-11-01

The main subject of the GEM meeting were: meson production near threshold, mesic atoms, nuclear resonances, symmetry violation, light ions structure and interactions. Additionally some apparatus problems like electronic equipment and charged particle detector have been discussed. The volume contains copies of transparencies supplied by the authors which are not normal full texts of papers

Financial recognition of material misstatement risks of listed companies on GEM

OpenAIRE

Jie Ming; Yicong Jiang

2017-01-01

Listed companies on GEM are characterized by strong innovation, great growth ability, high risks and high yields. Starting from these characteristics, this paper carries out analysis by using the financial indicators that are effective to recognize the material misstatement risks and easy to be acquired, and combines with the sample data with high material misstatement risks on GEM in 2012 to 2014 to test the significance of spss difference, and finds that the material misstatement company an...

Analysis of the state of the art in the GEM project on gender and entrepreneur ship, period 1999-2009; Analisis del estdo del arte en el proyecto GEM sobre genero y actividad emprendedora perio 1999-2009

Energy Technology Data Exchange (ETDEWEB)

Sanchez Escobedo, M. C.; Postigo Jimenez, M. V.; Hernandez Mogollon, R.

2012-11-01

This paper fundamental aims to analyse the situation and evolution of research on gender in creation of business that has used the Global Entrepreneur ship Monitor (GEM) data, since the inception of the project until the end of 2009. To do this, the authors carries out analysis methods biblio metric about research both nationally and internationally. The results of the study show the fundamental documents and their types, primary scientific articles, main journals of dissemination, authors, institutions and most productive countries as well as techniques of analysis and data sources used. (Author) 47 refs.

STELLAR CORONAE, SOLAR FLARES: A DETAILED COMPARISON OF {sigma} GEM, HR 1099, AND THE SUN IN HIGH-RESOLUTION X-RAYS

Energy Technology Data Exchange (ETDEWEB)

Huenemoerder, David P. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 70 Vassar St., Cambridge, MA 02139 (United States); Phillips, Kenneth J. H. [Visiting Scientist, Space Research Center, Polish Academy of Sciences, 51-622, Kopernika 11, Wroclaw (Poland); Sylwester, Janusz; Sylwester, Barbara, E-mail: dph@space.mit.edu, E-mail: kennethjhphillips@yahoo.com, E-mail: js@cbk.pan.wroc.pl, E-mail: bs@cbk.pan.wroc.pl [Space Research Center, Polish Academy of Sciences, 51-622, Kopernika 11, Wroclaw (Poland)

2013-05-10

The Chandra High Energy Transmission Grating Spectrometer (HETG) spectra of the coronally active binary stars {sigma} Gem and HR 1099 are among the highest fluence observations for such systems taken at high spectral resolution in X-rays with this instrument. This allows us to compare their properties in detail to solar flare spectra obtained with the Russian CORONAS-F spacecraft's RESIK instrument at similar resolution in an overlapping bandpass. Here we emphasize the detailed comparisons of the 3.3-6.1 A region (including emission from highly ionized S, Si, Ar, and K) from solar flare spectra to the corresponding {sigma} Gem and HR 1099 spectra. We also model the larger wavelength range of the HETG, from 1.7 to 25 A - having emission lines from Fe, Ca, Ar, Si, Al, Mg, Ne, O, and N-to determine coronal temperatures and abundances. {sigma} Gem is a single-lined coronally active long-period binary which has a very hot corona. HR 1099 is a similar, but shorter period, double-lined system. With very deep HETG exposures we can even study emission from some of the weaker species, such as K, Na, and Al, which are important since they have the lowest first ionization potentials, a parameter well known to be correlated with elemental fractionation in the solar corona. The solar flare temperatures reach Almost-Equal-To 20 MK, comparable to the {sigma} Gem and HR 1099 coronae. During the Chandra exposures, {sigma} Gem was slowly decaying from a flare and its spectrum is well characterized by a collisional ionization equilibrium plasma with a broad temperature distribution ranging from 2 to 60 MK, peaking near 25 MK, but with substantial emission from 50 MK plasma. We have detected K XVIII and Na XI emission which allow us to set limits on their abundances. HR 1099 was also quite variable in X-rays, also in a flare state, but had no detectable K XVIII. These measurements provide new comparisons of solar and stellar coronal abundances, especially at the lowest first

Implementation of the P barANDA Planar-GEM tracking detector in Monte Carlo simulations

Science.gov (United States)

Divani Veis, Nazila; Ehret, Andre; Firoozabadi, Mohammad M.; Karabowicz, Radoslaw; Maas, Frank; Saito, Nami; Saito, Takehiko R.; Voss, Bernd; PANDA Gem-Tracker Subgroup

2018-02-01

The P barANDA experiment at FAIR will be performed to investigate different aspects of hadron physics using anti-proton beams interacting with a fixed nuclear target. The experimental setup consists of a complex series of detector components covering a large solid angle. A detector with a gaseous active media equipped with gas electron multiplier (GEM) technique will be employed to measure tracks of charged particles at forward direction in order to achieve a high momentum resolution. In this work, a full setup of the GEM tracking detector has been implemented in the P barANDA Monte Carlo simulation package (PandaRoot) based on the current technical and conceptual design, and the expected performance of the P barANDA GEM-tracking detector has been investigated. Furthermore, material-budget studies in terms of the radiation length of the P barANDA GEM-tracking detector have been made in order to investigate the effect of the detector materials and its associated structures to particle measurements.

Energy resolution studies of an IROC GEM prototype for the ALICE TPC

Energy Technology Data Exchange (ETDEWEB)

Mathis, Andreas [TU Muenchen, Physik Department E12, Excellence Cluster ' ' Universe' ' , D-85748, Garching (Germany); Collaboration: ALICE-Collaboration

2015-07-01

The ALICE collaboration (A Large Ion Collider Experiment) is planning an upgrade of its central barrel detectors, to be able to cope with the increased LHC luminosity beyond 2018. In order to fully exploit the increase in collision rate to about 50 kHz in Pb-Pb, the TPC is foreseen to be operated in an ungated mode with continuous readout. This demands for a replacement of the currently used, gated MWPC by GEM-based readout chambers, while retaining the present tracking and particle identification capabilities of the TPC via measurement of the specific energy loss (dE/dx). The present baseline solution for the TPC upgrade consists of a stack of four large-sized GEM foils as amplification stage, containing both Standard (S, 140 μm) and Large Pitch (LP, 280 μm) GEM foils arranged in the order S-LP-LP-S. This arrangement has been proven as advantageous in terms of ion backflow and energy resolution. A prototype of an ALICE IROC (Inner Readout Chamber) was equipped with such a quadruple GEM stack, installed inside a field cage and exposed to a beam of electrons and pions from the CERN PS. The performance of the prototype in terms of energy resolution has been evaluated and is presented.

Sensitivity analysis of the GEMS soil organic carbon model to land cover land use classification uncertainties under different climate scenarios in Senegal

Science.gov (United States)

Dieye, A.M.; Roy, David P.; Hanan, N.P.; Liu, S.; Hansen, M.; Toure, A.

2012-01-01

Spatially explicit land cover land use (LCLU) change information is needed to drive biogeochemical models that simulate soil organic carbon (SOC) dynamics. Such information is increasingly being mapped using remotely sensed satellite data with classification schemes and uncertainties constrained by the sensing system, classification algorithms and land cover schemes. In this study, automated LCLU classification of multi-temporal Landsat satellite data were used to assess the sensitivity of SOC modeled by the Global Ensemble Biogeochemical Modeling System (GEMS). The GEMS was run for an area of 1560 km2 in Senegal under three climate change scenarios with LCLU maps generated using different Landsat classification approaches. This research provides a method to estimate the variability of SOC, specifically the SOC uncertainty due to satellite classification errors, which we show is dependent not only on the LCLU classification errors but also on where the LCLU classes occur relative to the other GEMS model inputs.

Study of gain variation as a function of physical parameters of GEM foil

CERN Document Server

Das, Supriya

2015-01-01

The ALICE experiment at LHC has planned to upgrade the TPC by replacing the MWPC with GEM based detecting elements to restrict the IBF to a tolerable value. However the variation of the gain as a function of physical parameters of industrially produced large size GEM foils is needed to be studied as a part of the QA procedure for the detector. The size of the electron avalanche and consequently the gain for GEM based detectors depend on the electric field distribution inside the holes. Geometry of a hole plays an important role in defining the electric field inside it. In this work we have studied the variation of the gain as a function of the hole diameters using Garfield++ simulation package.

Development of a GEM-based high rate TPC

Energy Technology Data Exchange (ETDEWEB)

Neubert, Sebastian; Hoeppner, Christian; Ketzer, Bernhard; Weitzel, Quirin; Paul, Stefan; Woerner, Lisa; Konorov, Igor; Mann, Alexander [Technische Universitaet Muenchen, Physik Department E18, Garching (Germany)

2008-07-01

A TPC is considered as the central tracker of the PANDA experiment, which is currently being planned at the new accelerator complex FAIR at Darmstadt. PANDA is designed as an internal target experiment at the antiproton storage ring HESR. The central tracker has to measure particle trajectories over a wide momentum range (0.1-8 GeV/c) from up to 2.10{sup 7} antiproton-proton annihilations/s. The continuous nature of the antiproton beam makes the use of a traditional ion gate impractical. Owing to their intrinsic ion suppression properties, GEM foils are planned as the amplification stage. A small prototype of this GEM-TPC (diameter 200 mm, drift length 77 mm) has been built and characterized with cosmic muons. Results such as spatial resolution, cluster distributions, and diffusion properties are presented in this talk.

Development of a GEM-based TPC for PANDA

Energy Technology Data Exchange (ETDEWEB)

Hoeppner, Christian; Ketzer, Bernhard; Konorov, Igor; Mann, Alexander; Neubert, Sebastian; Paul, Stephan; Weitzel, Quirin; Woerner, Lisa [Technische Universitaet Muenchen, Physik Department E18, 85748 Garching (Germany)

2008-07-01

A TPC is considered as the central tracker of the PANDA experiment, which is currently being planned at the new accelerator complex FAIR at Darmstadt. PANDA is designed as an internal target experiment at the antiproton storage ring HESR. The central tracker has to measure particle trajectories over a wide momentum range (0.1-8 GeV/c) from up to 2.10{sup 7} antiproton-proton annihilations/s. The continuous nature of the antiproton beam makes the use of a traditional ion gate impractical. Owing to their intrinsic ion suppression properties, GEM foils are planned as the amplification stage. A small prototype of this GEM-TPC (diameter 200 mm, drift length 77 mm) has been built and characterized with cosmic muons. Results such as spatial resolution, cluster distributions, and diffusion properties are presented in this talk.

Does GEM-Encoding Clinical Practice Guidelines Improve the Quality of Knowledge Bases? A Study with the Rule-Based Formalism

Science.gov (United States)

Georg, Gersende; Séroussi, Brigitte; Bouaud, Jacques

2003-01-01

The aim of this work was to determine whether the GEM-encoding step could improve the representation of clinical practice guidelines as formalized knowledge bases. We used the 1999 Canadian recommendations for the management of hypertension, chosen as the knowledge source in the ASTI project. We first clarified semantic ambiguities of therapeutic sequences recommended in the guideline by proposing an interpretative framework of therapeutic strategies. Then, after a formalization step to standardize the terms used to characterize clinical situations, we created the GEM-encoded instance of the guideline. We developed a module for the automatic derivation of a rule base, BR-GEM, from the instance. BR-GEM was then compared to the rule base, BR-ASTI, embedded within the critic mode of ASTI, and manually built by two physicians from the same Canadian guideline. As compared to BR-ASTI, BR-GEM is more specific and covers more clinical situations. When evaluated on 10 patient cases, the GEM-based approach led to promising results. PMID:14728173

Does GEM-encoding clinical practice guidelines improve the quality of knowledge bases? A study with the rule-based formalism.

Science.gov (United States)

Georg, Georg; Séroussi, Brigitte; Bouaud, Jacques

2003-01-01

The aim of this work was to determine whether the GEM-encoding step could improve the representation of clinical practice guidelines as formalized knowledge bases. We used the 1999 Canadian recommendations for the management of hypertension, chosen as the knowledge source in the ASTI project. We first clarified semantic ambiguities of therapeutic sequences recommended in the guideline by proposing an interpretative framework of therapeutic strategies. Then, after a formalization step to standardize the terms used to characterize clinical situations, we created the GEM-encoded instance of the guideline. We developed a module for the automatic derivation of a rule base, BR-GEM, from the instance. BR-GEM was then compared to the rule base, BR-ASTI, embedded within the critic mode of ASTI, and manually built by two physicians from the same Canadian guideline. As compared to BR-ASTI, BR-GEM is more specific and covers more clinical situations. When evaluated on 10 patient cases, the GEM-based approach led to promising results.

Financial recognition of material misstatement risks of listed companies on GEM

Directory of Open Access Journals (Sweden)

Jie Ming

2017-11-01

Full Text Available Listed companies on GEM are characterized by strong innovation, great growth ability, high risks and high yields. Starting from these characteristics, this paper carries out analysis by using the financial indicators that are effective to recognize the material misstatement risks and easy to be acquired, and combines with the sample data with high material misstatement risks on GEM in 2012 to 2014 to test the significance of spss difference, and finds that the material misstatement company and the normal company have significant difference in the profitability, solvency, growth ability and cash flow.

GPU Computing Gems Emerald Edition

CERN Document Server

Hwu, Wen-mei W

2011-01-01

".the perfect companion to Programming Massively Parallel Processors by Hwu & Kirk." -Nicolas Pinto, Research Scientist at Harvard & MIT, NVIDIA Fellow 2009-2010 Graphics processing units (GPUs) can do much more than render graphics. Scientists and researchers increasingly look to GPUs to improve the efficiency and performance of computationally-intensive experiments across a range of disciplines. GPU Computing Gems: Emerald Edition brings their techniques to you, showcasing GPU-based solutions including: Black hole simulations with CUDA GPU-accelerated computation and interactive display of

ESTADO DE LA EDUCACIÓN Y FORMACIÓN EMPRESARIAL EN LOS PAÍSES Y REGIONES ESPAÑOLAS DEL GEM

Directory of Open Access Journals (Sweden)

Ana Fernández Laviada

2014-12-01

Full Text Available Specialised literature presents education and training as a determining factor for entrepreneurship. However, time and time again experts at the Global Entrepreneurship Monitor (GEM have stated that it’s one lowest, and sometimes the least, valued elements in this area. Therefore, the objective of this study is to analyse the state of entrepreneurship education and training in its different stages within the countries and regions that participated in GEM 2012. Specifically, what is sought is, based on the opinion of the experts, the state of entrepreneurship training and education in each level analysed in GEM, generically as well as by country, while looking at the possible differences (strengths and weaknesses that appear in each one. Furthermore, this is paired with a national analysis that examines the situation of the different participating regions in the study. In order to carry out the analysis, the 2012 NES database is used. In that edition, a total of 69 countries participated and, in the case of Spain, there were 14 regions all with 36 experts in each. The data processing is carried out using the Rasch model for measurement. The preliminary results show that, in general, university level education geared towards entrepreneurship is more highly developed than at the lower levels of education, such as in secondary and primary education. Nevertheless, the individual analysis makes it possible to detect differences between countries and regions.

Building a large-area GEM-based readout chamber for the upgrade of the ALICE TPC

CERN Document Server

Gasik, Piotr

2017-01-01

A large Time Projection Chamber (TPC) is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019-2020, the LHC will deliver Pb beams colliding at an interaction rate up to 50 kHz, which is about a factor of 100 above the present read-out rate of the TPC. To fully exploit the LHC potential the TPC will be upgraded based on the Gas Electron Multiplier (GEM) technology. A prototype of an ALICE TPC Outer Read-Out Chamber (OROC) was equipped with twelve large-size GEM foils as amplification stage to demonstrate the feasibility of replacing the current Multi Wire Proportional Chambers with the new technology. With a total area of $\\sim$0.76 m$^2$ it is the largest GEM-based detector built to date. The GEM OROC was installed within a test field cage and commissioned with radioactive sources.

Building a large-area GEM-based readout chamber for the upgrade of the ALICE TPC

Energy Technology Data Exchange (ETDEWEB)

Gasik, P. [Physik Department E62, Technische Universität München, Garching (Germany); Excellence Cluster ‘Origin and Structure of the Universe’, Garching (Germany)

2017-02-11

A large Time Projection Chamber (TPC) is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019–2020, the LHC will deliver Pb beams colliding at an interaction rate up to 50 kHz, which is about a factor of 100 above the present read-out rate of the TPC. To fully exploit the LHC potential the TPC will be upgraded based on the Gas Electron Multiplier (GEM) technology. A prototype of an ALICE TPC Outer Read-Out Chamber (OROC) was equipped with twelve large-size GEM foils as amplification stage to demonstrate the feasibility of replacing the current Multi Wire Proportional Chambers with the new technology. With a total area of ∼0.76 m{sup 2} it is the largest GEM-based detector built to date. The GEM OROC was installed within a test field cage and commissioned with radioactive sources.

Building a large-area GEM-based readout chamber for the upgrade of the ALICE TPC

International Nuclear Information System (INIS)

Gasik, P.

2017-01-01

A large Time Projection Chamber (TPC) is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019–2020, the LHC will deliver Pb beams colliding at an interaction rate up to 50 kHz, which is about a factor of 100 above the present read-out rate of the TPC. To fully exploit the LHC potential the TPC will be upgraded based on the Gas Electron Multiplier (GEM) technology. A prototype of an ALICE TPC Outer Read-Out Chamber (OROC) was equipped with twelve large-size GEM foils as amplification stage to demonstrate the feasibility of replacing the current Multi Wire Proportional Chambers with the new technology. With a total area of ∼0.76 m 2 it is the largest GEM-based detector built to date. The GEM OROC was installed within a test field cage and commissioned with radioactive sources.

Detection and Imaging of High-Z Materials with a Muon Tomography Station Using GEM Detectors

CERN Document Server

Gnanvo, K; Bittner, W; Costa, F; Grasso, L; Hohlmann, M; Locke, J B; Martoiu, S; Muller, H; Staib, M; Tarazona, A; Toledo, J

2010-01-01

Muon tomography based on the measurement of multiple scattering of atmospheric cosmic ray muons is a promising technique for detecting and imaging heavily shielded high-Z nuclear materials such as enriched uranium. This technique could complement standard radiation detection portals currently deployed at international borders and ports, which are not very sensitive to heavily shielded nuclear materials. We image small targets in 3D using $2\\times 2 \\times 2$ mm^3 voxels with a minimal muon tomography station prototype that tracks muons with Gas Electron Multiplier (GEM) detectors read out in 2D with x-y microstrips of 400 micron pitch. With preliminary electronics, the GEM detectors achieve a spatial resolution of 130 microns in both dimensions. With the next GEM-based prototype station we plan to probe an active volume of ~27 liters. We present first results on reading out all 1536 microstrips of a $30 \\times 30$ cm^2 GEM detector for the next muon tomography prototype with final frontend electronics and DAQ...

Resolution studies of a GEM-based TPC

Energy Technology Data Exchange (ETDEWEB)

Killenberg, M.

2006-12-15

Currently there are four different concept studies trying to optimise the detector for the requirements at the ILC. In three of these detector concepts a time projection chamber (TPC) is foreseen as the main tracking device. To achieve the intended spatial resolution of 100 {mu}m, micro pattern gas detectors (MPGD) are considered for gas amplification. The two different MPGDs discussed for the ILC TPC are Micro-Mesh Gaseous Detectors (Micromegas) and Gas Electron Multiplier foils (GEMs). The current thesis shows resolution studies with a TPC prototype equipped with a triple GEM readout structure. A hodoscope made up of silicon strip sensors gives a precision reference track, allowing an unbiased measurement of the spatial resolution. High statistics measurements have been conducted at the DESY test beam facility, which provides positrons with a tunable energy between 1 GeV and 6 GeV. Using the independent measurement of the hodoscope allows systematic studies of the homogeneity of the TPC's electric field. The fluctuations of the field in the chamber's central region were found to be {delta}E/E=8.10{sup -3}. Field distortions have been determined and corrected, reducing the remaining deviations to a level well below the spatial resolution of the TPC. One important task is to reduce the number of ions drifting back into the sensitive volume. Special GEM settings with minimised ion backdrift have been examined with respect to their influence on the spatial resolution and it was found that the spatial resolution is not degraded using these special settings. The TPC prototype has been operated in a 4 T magnetic field, provided by a superconducting solenoid located at DESY Hamburg. Again the spatial resolution measured with the ion backdrift optimised settings is compared to that achieved with nonoptimised settings. In both cases the measured resolution is approximately 130 {mu}m. (orig.)

Resolution studies of a GEM-based TPC

International Nuclear Information System (INIS)

Killenberg, M.

2006-01-01

Currently there are four different concept studies trying to optimise the detector for the requirements at the ILC. In three of these detector concepts a time projection chamber (TPC) is foreseen as the main tracking device. To achieve the intended spatial resolution of 100 μm, micro pattern gas detectors (MPGD) are considered for gas amplification. The two different MPGDs discussed for the ILC TPC are Micro-Mesh Gaseous Detectors (Micromegas) and Gas Electron Multiplier foils (GEMs). The current thesis shows resolution studies with a TPC prototype equipped with a triple GEM readout structure. A hodoscope made up of silicon strip sensors gives a precision reference track, allowing an unbiased measurement of the spatial resolution. High statistics measurements have been conducted at the DESY test beam facility, which provides positrons with a tunable energy between 1 GeV and 6 GeV. Using the independent measurement of the hodoscope allows systematic studies of the homogeneity of the TPC's electric field. The fluctuations of the field in the chamber's central region were found to be ΔE/E=8.10 -3 . Field distortions have been determined and corrected, reducing the remaining deviations to a level well below the spatial resolution of the TPC. One important task is to reduce the number of ions drifting back into the sensitive volume. Special GEM settings with minimised ion backdrift have been examined with respect to their influence on the spatial resolution and it was found that the spatial resolution is not degraded using these special settings. The TPC prototype has been operated in a 4 T magnetic field, provided by a superconducting solenoid located at DESY Hamburg. Again the spatial resolution measured with the ion backdrift optimised settings is compared to that achieved with nonoptimised settings. In both cases the measured resolution is approximately 130 μm. (orig.)

The Mitochondrial GTPase Gem1 Contributes to the Cell Wall Stress Response and Invasive Growth of Candida albicans

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Barbara Koch

2017-12-01

Full Text Available The interactions of mitochondria with the endoplasmic reticulum (ER are crucial for maintaining proper mitochondrial morphology, function and dynamics. This enables cells to utilize their mitochondria optimally for energy production and anabolism, and it further provides for metabolic control over developmental decisions. In fungi, a key mechanism by which ER and mitochondria interact is via a membrane tether, the protein complex ERMES (ER-Mitochondria Encounter Structure. In the model yeast Saccharomyces cerevisiae, the mitochondrial GTPase Gem1 interacts with ERMES, and it has been proposed to regulate its activity. Here we report on the first characterization of Gem1 in a human fungal pathogen. We show that in Candida albicans Gem1 has a dominant role in ensuring proper mitochondrial morphology, and our data is consistent with Gem1 working with ERMES in this role. Mitochondrial respiration and steady state cellular phospholipid homeostasis are not impacted by inactivation of GEM1 in C. albicans. There are two major virulence-related consequences of disrupting mitochondrial morphology by GEM1 inactivation: C. albicans becomes hypersusceptible to cell wall stress, and is unable to grow invasively. In the gem1Δ/Δ mutant, it is specifically the invasive capacity of hyphae that is compromised, not the ability to transition from yeast to hyphal morphology, and this phenotype is shared with ERMES mutants. As a consequence of the hyphal invasion defect, the gem1Δ/Δ mutant is drastically hypovirulent in the worm infection model. Activation of the mitogen activated protein (MAP kinase Cek1 is reduced in the gem1Δ/Δ mutant, and this function could explain both the susceptibility to cell wall stress and lack of invasive growth. This result establishes a new, respiration-independent mechanism of mitochondrial control over stress signaling and hyphal functions in C. albicans. We propose that ER-mitochondria interactions and the ER

The Mitochondrial GTPase Gem1 Contributes to the Cell Wall Stress Response and Invasive Growth of Candida albicans.

Science.gov (United States)

Koch, Barbara; Tucey, Timothy M; Lo, Tricia L; Novakovic, Stevan; Boag, Peter; Traven, Ana

2017-01-01

The interactions of mitochondria with the endoplasmic reticulum (ER) are crucial for maintaining proper mitochondrial morphology, function and dynamics. This enables cells to utilize their mitochondria optimally for energy production and anabolism, and it further provides for metabolic control over developmental decisions. In fungi, a key mechanism by which ER and mitochondria interact is via a membrane tether, the protein complex ERMES (ER-Mitochondria Encounter Structure). In the model yeast Saccharomyces cerevisiae , the mitochondrial GTPase Gem1 interacts with ERMES, and it has been proposed to regulate its activity. Here we report on the first characterization of Gem1 in a human fungal pathogen. We show that in Candida albicans Gem1 has a dominant role in ensuring proper mitochondrial morphology, and our data is consistent with Gem1 working with ERMES in this role. Mitochondrial respiration and steady state cellular phospholipid homeostasis are not impacted by inactivation of GEM1 in C. albicans . There are two major virulence-related consequences of disrupting mitochondrial morphology by GEM1 inactivation: C. albicans becomes hypersusceptible to cell wall stress, and is unable to grow invasively. In the gem1 Δ / Δ mutant, it is specifically the invasive capacity of hyphae that is compromised, not the ability to transition from yeast to hyphal morphology, and this phenotype is shared with ERMES mutants. As a consequence of the hyphal invasion defect, the gem1 Δ / Δ mutant is drastically hypovirulent in the worm infection model. Activation of the mitogen activated protein (MAP) kinase Cek1 is reduced in the gem1 Δ / Δ mutant, and this function could explain both the susceptibility to cell wall stress and lack of invasive growth. This result establishes a new, respiration-independent mechanism of mitochondrial control over stress signaling and hyphal functions in C. albicans . We propose that ER-mitochondria interactions and the ER-Mitochondria Organizing

Quality of the spare triple-GEM detectors

CERN Document Server

Lenci, Rosario; Paoletti, Emiliano; Pasquali, Luigi; Pinci, Davide; Piscitelli, Carmelo; Poli Lener, Marco; Sciubba, Adalberto; Tskhadadze, Edisher

2017-01-01

Triple-GEM chambers equip the inner region of the M1 muon station. In order to provide spare detectors in case of problems in the operating ones, new chambers have been assembled at the Frascati National Laboratories of the INFN. This note summarizes the results of the quality tests performed at the end of the production procedure.

Investigating the effect of entrepreneurial competencies on business performance among early stage entrepreneurs Global Entrepreneurship Monitor (GEM 2010 survey data)

OpenAIRE

Barazandeh, Mahtab; Parvizian, Kourosh; Alizadeh, Mehdi; Khosravi, Saber

2015-01-01

Entrepreneurs of this era need to be more competent and skillful compared to businessmen working in the beginning of this century. A robust body of knowledge has grown around entrepreneurs' need for superior skills and personality characteristics; the ones that enables them to effectively compete and survive. In this study, we analyzed the relationship between entrepreneurial competencies along with social norms and entrepreneurs' business performance. Data of GEM gathered during 2010 was uti...

The DiGEM trial protocol – a randomised controlled trial to determine the effect on glycaemic control of different strategies of blood glucose self-monitoring in people with type 2 diabetes [ISRCTN47464659

Directory of Open Access Journals (Sweden)

Goyder Elizabeth

2005-06-01

Full Text Available Abstract Background We do not yet know how to use blood glucose self-monitoring (BGSM most effectively in the self-management of type 2 diabetes treated with oral medication. Training in monitoring may be most effective in improving glycaemic control and well being when results are linked to behavioural change. Methods/design DiGEM is a three arm randomised parallel group trial set in UK general practices. A total of 450 patients with type 2 diabetes managed with lifestyle or oral glucose lowering medication are included. The trial compares effectiveness of three strategies for monitoring glycaemic control over 12 months (1 a control group with three monthly HbA1c measurements; interpreted with nurse-practitioner; (2 A self-testing of blood glucose group; interpreted with nurse- practitioner to inform adjustment of medication in addition to 1; (3 A self-monitoring of blood glucose group with personal use of results to interpret results in relation to lifestyle changes in addition to 1 and 2. The trial has an 80% power at a 5% level of significance to detect a difference in change in the primary outcome, HbA1c of 0.5% between groups, allowing for an attrition rate of 10%. Secondary outcome measures include health service costs, well-being, and the intervention effect in sub-groups defined by duration of diabetes, current management, health status at baseline and co-morbidity. A mediation analysis will explore the extent to which changes in beliefs about self-management of diabetes between experimental groups leads to changes in outcomes in accordance with the Common Sense Model of illness. The study is open and has recruited more than half the target sample. The trial is expected to report in 2007. Discussion The DiGEM intervention and trial design address weaknesses of previous research by use of a sample size with power to detect a clinically significant change in HbA1c, recruitment from a well-characterised primary care population, definition

Deoxygenative gem-difluoroolefination of carbonyl compounds with (chlorodifluoromethyltrimethylsilane and triphenylphosphine

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Fei Wang

2014-02-01

Full Text Available Background: 1,1-Difluoroalkenes cannot only be used as valuable precursors for organic synthesis, but also act as bioisosteres for enzyme inhibitors. Among various methods for their preparation, the carbonyl olefination with difluoromethylene phosphonium ylide represents one of the most straightforward methods.Results: The combination of (chlorodifluoromethyltrimethylsilane (TMSCF2Cl and triphenylphosphine (PPh3 can be used for the synthesis of gem-difluoroolefins from carbonyl compounds. Comparative experiments demonstrate that TMSCF2Cl is superior to (bromodifluoromethyltrimethylsilane (TMSCF2Br and (trifluoromethyltrimethylsilane (TMSCF3 in this reaction.Conclusion: Similar to many other Wittig-type gem-difluoroolefination reactions in the presence of PPh3, the reaction of TMSCF2Cl with aldehydes and activated ketones is effective.

Use of laser induced breakdown spectroscopy in the determination of gem provenance: beryls

International Nuclear Information System (INIS)

McManus, Catherine E.; McMillan, Nancy J.; Harmon, Russell S.; Whitmore, Robert C.; De Lucia, Frank C. Jr.; Miziolek, Andrzej W.

2008-01-01

The provenance of gem stones has been of interest to geologists, gemologists, archeologists, and historians for centuries. Laser induced breakdown spectroscopy (LIBS) provides a minimally destructive tool for recording the rich chemical signatures of gem beryls (aquamarine, goshenite, heliodor, and morganite). Broadband LIBS spectra of 39 beryl (Be3Al2Si6O18) specimens from 11 pegmatite mines in New Hampshire, Connecticut, and Maine (USA) are used to assess the potential of using principal component analysis of LIBS spectra to determine specimen provenance. Using this technique, beryls from the three beryl-bearing zones in the Palermo no. 1 pegmatite (New Hampshire) can be recognized. However, the compositional variation within this single mine is comparable to that in beryls from all three states. Thus, a very large database with detailed location metadata will be required to routinely determine gem beryl provenance

A process-based evaluation of dust-emitting winds in the CMIP5 simulation of HadGEM2-ES

Science.gov (United States)

Fiedler, Stephanie; Knippertz, Peter; Woodward, Stephanie; Martin, Gill M.; Bellouin, Nicolas; Ross, Andrew N.; Heinold, Bernd; Schepanski, Kerstin; Birch, Cathryn E.; Tegen, Ina

2016-02-01

Despite the importance of dust aerosol in the Earth system, state-of-the-art models show a large variety for North African dust emission. This study presents a systematic evaluation of dust emitting-winds in 30 years of the historical model simulation with the UK Met Office Earth-system model HadGEM2-ES for the Coupled Model Intercomparison Project Phase 5. Isolating the effect of winds on dust emission and using an automated detection for nocturnal low-level jets (NLLJs) allow an in-depth evaluation of the model performance for dust emission from a meteorological perspective. The findings highlight that NLLJs are a key driver for dust emission in HadGEM2-ES in terms of occurrence frequency and strength. The annually and spatially averaged occurrence frequency of NLLJs is similar in HadGEM2-ES and ERA-Interim from the European Centre for Medium-Range Weather Forecasts. Compared to ERA-Interim, a stronger pressure ridge over northern Africa in winter and the southward displaced heat low in summer result in differences in location and strength of NLLJs. Particularly the larger geostrophic winds associated with the stronger ridge have a strengthening effect on NLLJs over parts of West Africa in winter. Stronger NLLJs in summer may rather result from an artificially increased mixing coefficient under stable stratification that is weaker in HadGEM2-ES. NLLJs in the Bodélé Depression are affected by stronger synoptic-scale pressure gradients in HadGEM2-ES. Wintertime geostrophic winds can even be so strong that the associated vertical wind shear prevents the formation of NLLJs. These results call for further model improvements in the synoptic-scale dynamics and the physical parametrization of the nocturnal stable boundary layer to better represent dust-emitting processes in the atmospheric model. The new approach could be used for identifying systematic behavior in other models with respect to meteorological processes for dust emission. This would help to improve dust

Stability studies on GEM prototypes for the upgrade of the ALICE TPC

CERN Document Server

Cortinas Rodriguo Gaston, CRG

2013-01-01

In this work we show results of experiments aiming to understand the stability of a Gas Electron Multiplier (GEM) detector. While operating the detector, we monitor temperature, pressure and humidity in order to understand the contribution of each of these parameters to the behaviour of the devise. We also use a Single Wire proportional counter as a reference detector so to keep track of the gain fluctuations given by external influences (pressure, temperature, gas composition, etc.). In this way it is possible to spot fluctuation due to the intrinsic properties of these new detectors. A special effort is devoted to explaining and discussing different experimental drawbacks that appeared on the way in order to set a precedent, and as far as possible to avoid them in future experiences.

Towards an automatic wind speed and direction profiler for Wide Field adaptive optics systems

Science.gov (United States)

Sivo, G.; Turchi, A.; Masciadri, E.; Guesalaga, A.; Neichel, B.

2018-05-01

Wide Field Adaptive Optics (WFAO) systems are among the most sophisticated adaptive optics (AO) systems available today on large telescopes. Knowledge of the vertical spatio-temporal distribution of wind speed (WS) and direction (WD) is fundamental to optimize the performance of such systems. Previous studies already proved that the Gemini Multi-Conjugated AO system (GeMS) is able to retrieve measurements of the WS and WD stratification using the SLOpe Detection And Ranging (SLODAR) technique and to store measurements in the telemetry data. In order to assess the reliability of these estimates and of the SLODAR technique applied to such complex AO systems, in this study we compared WS and WD values retrieved from GeMS with those obtained with the atmospheric model Meso-NH on a rich statistical sample of nights. It has previously been proved that the latter technique provided excellent agreement with a large sample of radiosoundings, both in statistical terms and on individual flights. It can be considered, therefore, as an independent reference. The excellent agreement between GeMS measurements and the model that we find in this study proves the robustness of the SLODAR approach. To bypass the complex procedures necessary to achieve automatic measurements of the wind with GeMS, we propose a simple automatic method to monitor nightly WS and WD using Meso-NH model estimates. Such a method can be applied to whatever present or new-generation facilities are supported by WFAO systems. The interest of this study is, therefore, well beyond the optimization of GeMS performance.

Secondary scintillation yield from GEM and THGEM gaseous electron multipliers for direct dark matter search

Science.gov (United States)

Monteiro, C. M. B.; Fernandes, L. M. P.; Veloso, J. F. C. A.; Oliveira, C. A. B.; dos Santos, J. M. F.

2012-07-01

The search for alternatives to PMTs as photosensors in optical TPCs for rare event detection has significantly increased in the last few years. In particular, in view of the next generation large volume detectors, the use of photosensors with lower natural radioactivity, such as large area APDs or GM-APDs, with the additional possibility of sparse surface coverage, triggered the intense study of secondary scintillation production in micropattern electron multipliers, such as GEMs and THGEMs, as alternatives to the commonly used uniform electric field region between two parallel meshes. The much higher scintillation output obtained from the electron avalanches in such microstructures presents an advantage in those situations. The accurate knowledge of the amount of such scintillation is important for correct detector simulation and optimization. It will also serve as a benchmark for software tools developed and/or under development for the calculation of the amount of such scintillation.The secondary scintillation yield, or electroluminescence yield, in the electron avalanches of GEMs and THGEMs operating in gaseous xenon and argon has been determined for different gas pressures. At 1 bar, THGEMs deliver electroluminescence yields that are more than one order of magnitude higher when compared to those achieved in GEMs and two orders of magnitude when compared to those achieved in a uniform field gap. The THGEM electroluminescence yield presents a faster decrease with pressure when comparing to the GEM electroluminescence yield, reaching similar values to what is achieved in GEMs for xenon pressures of 2.5 bar, but still one order of magnitude higher than that produced in a uniform field gap. Another exception is the GEM operating in argon, which presents an electroluminescence yield similar to that produced in a uniform electric field gap, while the THGEM achieves yields that are more than one order of magnitude higher.

Advances in Trace Element “Fingerprinting” of Gem Corundum, Ruby and Sapphire, Mogok Area, Myanmar

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F. Lin Sutherland

2014-12-01

Full Text Available Mogok gem corundum samples from twelve localities were analyzed for trace element signatures (LA-ICP-MS method and oxygen isotope values (δ18O, by laser fluorination. The study augmented earlier findings on Mogok gem suites that suggested the Mogok tract forms a high vanadium gem corundum area and also identified rare alluvial ruby and sapphire grains characterised by unusually high silicon, calcium and gallium, presence of noticeable boron, tin and niobium and very low iron, titanium and magnesium contents. Oxygen isotope values (δ18O for the ruby and high Si-Ca-Ga corundum (20‰–25‰ and for sapphire (10‰–20‰ indicate typical crustal values, with values >20‰ being typical of carbonate genesis. The high Si-Ca-Ga ruby has high chromium (up to 3.2 wt % Cr and gallium (up to 0. 08 wt % Ga compared to most Mogok ruby (<2 wt % Cr; <0.02 wt % Ga. In trace element ratio plots the Si-Ca-Ga-rich corundum falls into separate fields from the typical Mogok metamorphic fields. The high Ga/Mg ratios (46–521 lie well within the magmatic range (>6, and with other features suggest a potential skarn-like, carbonate-related genesis with a high degree of magmatic fluid input The overall trace element results widen the range of different signatures identified within Mogok gem corundum suites and indicate complex genesis. The expanded geochemical platform, related to a variety of metamorphic, metasomatic and magmatic sources, now provides a wider base for geographic typing of Mogok gem corundum suites. It allows more detailed comparisons with suites from other deposits and will assist identification of Mogok gem corundum sources used in jewelry.

Study of the spatial resolution of low-material GEM tracking detectors

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Kudryavtsev V.N.

2018-01-01

Full Text Available The spatial resolution of GEM based tracking detectors has been simulated and measured. The simulation includes the GEANT4 based transport of high energy electrons with careful accounting for atomic relaxation processes including emission of fluorescent photons and Auger electrons and custom post-processing, including accounting for diffusion, gas amplification fluctuations, the distribution of signals on readout electrodes, electronics noise and a particular algorithm of the final coordinate calculation (center of gravity. The simulation demonstrates that a minimum of the spatial resolution of about 10 μm can be achieved with strip pitches from 250 μm to 300 μm. For larger pitches the resolution is quickly degrading reaching 80-100 μm at a pitch of 500 μm. The spatial resolution of low-material triple-GEM detectors for the DEUTRON facility at the VEPP-3 storage ring is measured at the extracted beam facility of the VEPP-4M collider. The amount of material in these detectors is reduced by etching the copper of the GEMs electrodes and using a readout structure on a thin kapton foil rather than on a glass fibre plate. The exact amount of material in one DEUTRON detector is measured by studying multiple scattering of 100 MeV electrons in it. The result of these measurements is X/X0 = 2.4×10−3 corresponding to a thickness of the copper layers of the GEM foils of 3 μm. The spatial resolution of one DEUTRON detector is measured with 500 MeV electrons and the measured value is equal to 35 ± 1 μm for orthogonal tracks.

Study of the spatial resolution of low-material GEM tracking detectors

Science.gov (United States)

Kudryavtsev, V. N.; Maltsev, T. V.; Shekhtman, L. I.

2018-02-01

The spatial resolution of GEM based tracking detectors has been simulated and measured. The simulation includes the GEANT4 based transport of high energy electrons with careful accounting for atomic relaxation processes including emission of fluorescent photons and Auger electrons and custom post-processing, including accounting for diffusion, gas amplification fluctuations, the distribution of signals on readout electrodes, electronics noise and a particular algorithm of the final coordinate calculation (center of gravity). The simulation demonstrates that a minimum of the spatial resolution of about 10 μm can be achieved with strip pitches from 250 μm to 300 μm. For larger pitches the resolution is quickly degrading reaching 80-100 μm at a pitch of 500 μm. The spatial resolution of low-material triple-GEM detectors for the DEUTRON facility at the VEPP-3 storage ring is measured at the extracted beam facility of the VEPP-4M collider. The amount of material in these detectors is reduced by etching the copper of the GEMs electrodes and using a readout structure on a thin kapton foil rather than on a glass fibre plate. The exact amount of material in one DEUTRON detector is measured by studying multiple scattering of 100 MeV electrons in it. The result of these measurements is X/X0 = 2.4×10-3 corresponding to a thickness of the copper layers of the GEM foils of 3 μm. The spatial resolution of one DEUTRON detector is measured with 500 MeV electrons and the measured value is equal to 35 ± 1 μm for orthogonal tracks.

A Cylindrical GEM Detector with Analog Readout for the BESIII Experiment

Energy Technology Data Exchange (ETDEWEB)

Cibinetto, G. [BESIII CGEM group, INFN Ferrara (Italy)

2015-07-01

Inner Trackers (IT) are key detectors in Particle Physics experiments; excellent spatial resolution, radiation transparency and hardness, and operability under high occupancies are main requirements. We aim to design, build and commission by 2017 a Cylindrical GEM (CGEM) detector candidate to be the new IT of the BESIII spectrometer, hosted on BEPC2 in IHEP, Beijing; BESIII data taking will last until at least 2020. The IT itself will represent an evolution w.r.t. the state of the art of GEM detectors, since the use of new kind of mechanical supports for the GEM foils will reduce the total radiation length of the detector and improve its tracking performance; an innovative design of the CGEM anode will allow for smaller capacitance and hence for bigger signals. The relatively strong BESIII magnetic field requires a new analogue readout; full custom front-end electronics, including a dedicated ASIC, will be designed and produced for optimal data collection. Prototype Beam Test results showing the measurement of the spatial resolution in a 1 Tesla magnetic field will be presented among with the mechanical design and simulations. (authors)

Idealized climate change simulations with a high-resolution physical model: HadGEM3-GC2

Science.gov (United States)

Senior, Catherine A.; Andrews, Timothy; Burton, Chantelle; Chadwick, Robin; Copsey, Dan; Graham, Tim; Hyder, Pat; Jackson, Laura; McDonald, Ruth; Ridley, Jeff; Ringer, Mark; Tsushima, Yoko

2016-06-01

Idealized climate change simulations with a new physical climate model, HadGEM3-GC2 from The Met Office Hadley Centre are presented and contrasted with the earlier MOHC model, HadGEM2-ES. The role of atmospheric resolution is also investigated. The Transient Climate Response (TCR) is 1.9 K/2.1 K at N216/N96 and Effective Climate Sensitivity (ECS) is 3.1 K/3.2 K at N216/N96. These are substantially lower than HadGEM2-ES (TCR: 2.5 K; ECS: 4.6 K) arising from a combination of changes in the size of climate feedbacks. While the change in the net cloud feedback between HadGEM3 and HadGEM2 is relatively small, there is a change in sign of its longwave and a strengthening of its shortwave components. At a global scale, there is little impact of the increase in atmospheric resolution on the future climate change signal and even at a broad regional scale, many features are robust including tropical rainfall changes, however, there are some significant exceptions. For the North Atlantic and western Europe, the tripolar pattern of winter storm changes found in most CMIP5 models is little impacted by resolution but for the most intense storms, there is a larger percentage increase in number at higher resolution than at lower resolution. Arctic sea-ice sensitivity shows a larger dependence on resolution than on atmospheric physics.

Spatial resolution studies of a GEM-TPC

Energy Technology Data Exchange (ETDEWEB)

Berger, Martin [TU Muenchen, 85748 Garching (Germany); Collaboration: GEM-TPC-Collaboration

2015-07-01

A GEM-TPC can exploit the intrinsic suppression of back drifting ions from the amplification stage of the GEM (Gas Electron Multiplier) foils to overcome the problem of drift-field distortions in an ungated operation. To explore the possibility of such a continuously running TPC (Time Projection Chamber) a large-size detector was built. This detector, with a drift length of 728 mm and a radius of 308 mm and a total of 10254 electronic channels, was designed as an upgrade for the FOPI experiment at GSI (Darmstadt, Germany) to improve the secondary vertex resolution especially for K{sup 0}{sub S}- and Λ-reconstruction and the PID capabilities. After commissioning a large statistics of cosmic data and beam-target reactions has been collected and the obtained tracks in the TPC have been used to improve the tracking algorithms. During the track finding and fitting procedure a clustering algorithm which takes into account the track topology as well as the full 3D spatial information is employed. The the clustering algorithm, the cluster error calculation and the tracking resolution are discussed in this contribution.

GEM: a dynamic tracking model for mesoscale eddies in the ocean

Science.gov (United States)

Li, Qiu-Yang; Sun, Liang; Lin, Sheng-Fu

2016-12-01

The Genealogical Evolution Model (GEM) presented here is an efficient logical model used to track dynamic evolution of mesoscale eddies in the ocean. It can distinguish between different dynamic processes (e.g., merging and splitting) within a dynamic evolution pattern, which is difficult to accomplish using other tracking methods. To this end, the GEM first uses a two-dimensional (2-D) similarity vector (i.e., a pair of ratios of overlap area between two eddies to the area of each eddy) rather than a scalar to measure the similarity between eddies, which effectively solves the "missing eddy" problem (temporarily lost eddy in tracking). Second, for tracking when an eddy splits, the GEM uses both "parent" (the original eddy) and "child" (eddy split from parent) and the dynamic processes are described as the birth and death of different generations. Additionally, a new look-ahead approach with selection rules effectively simplifies computation and recording. All of the computational steps are linear and do not include iteration. Given the pixel number of the target region L, the maximum number of eddies M, the number N of look-ahead time steps, and the total number of time steps T, the total computer time is O(LM(N + 1)T). The tracking of each eddy is very smooth because we require that the snapshots of each eddy on adjacent days overlap one another. Although eddy splitting or merging is ubiquitous in the ocean, they have different geographic distributions in the North Pacific Ocean. Both the merging and splitting rates of the eddies are high, especially at the western boundary, in currents and in "eddy deserts". The GEM is useful not only for satellite-based observational data, but also for numerical simulation outputs. It is potentially useful for studying dynamic processes in other related fields, e.g., the dynamics of cyclones in meteorology.

Comparison of the HadGEM2 climate-chemistry model against in situ and SCIAMACHY atmospheric methane data

Directory of Open Access Journals (Sweden)

G. D. Hayman

2014-12-01

Full Text Available Wetlands are a major emission source of methane (CH4 globally. In this study, we evaluate wetland emission estimates derived using the UK community land surface model (JULES, the Joint UK Land Earth Simulator against atmospheric observations of methane, including, for the first time, total methane columns derived from the SCIAMACHY instrument on board the ENVISAT satellite. Two JULES wetland emission estimates are investigated: (a from an offline run driven with Climatic Research Unit–National Centers for Environmental Prediction (CRU-NCEP meteorological data and (b from the same offline run in which the modelled wetland fractions are replaced with those derived from the Global Inundation Extent from Multi-Satellites (GIEMS remote sensing product. The mean annual emission assumed for each inventory (181 Tg CH4 per annum over the period 1999–2007 is in line with other recently published estimates. There are regional differences as the unconstrained JULES inventory gives significantly higher emissions in the Amazon (by ~36 Tg CH4 yr−1 and lower emissions in other regions (by up to 10 Tg CH4 yr−1 compared to the JULES estimates constrained with the GIEMS product. Using the UK Hadley Centre's Earth System model with atmospheric chemistry (HadGEM2, we evaluate these JULES wetland emissions against atmospheric observations of methane. We obtain improved agreement with the surface concentration measurements, especially at high northern latitudes, compared to previous HadGEM2 runs using the wetland emission data set of Fung et al. (1991. Although the modelled monthly atmospheric methane columns reproduce the large-scale patterns in the SCIAMACHY observations, they are biased low by 50 part per billion by volume (ppb. Replacing the HadGEM2 modelled concentrations above 300 hPa with HALOE–ACE assimilated TOMCAT output results in a significantly better agreement with the SCIAMACHY observations. The use of the GIEMS product to constrain the JULES

The monitoring of atmospheric mercury species in the Southern Indian Ocean at Amsterdam Island (38°S

Directory of Open Access Journals (Sweden)

Barret M.

2013-04-01

Full Text Available The role of oceans in the global cycle of mercury is still poorly characterized, mainly because of a lack a long-term data on atmospheric mercury concentrations in the remote Southern Ocean. In the frame of GMOS (Global Mercury Observation System, we present here the first results from a new monitoring station at Amsterdam Island in the Southern Indian Ocean. For the period January to April 2012, we recorded mean concentration of gaseous elemental mercury (GEM, reactive gaseous mercury (RGM and particulate-bounded mercury (PHg of 1.03 ng m−3, 0.37 and 0.34 pg m−3 respectively. While GEM concentrations showed little variations, RGM and PHg exhibited fast variations with alternation of value below the instrumental detection limit and maximum values up to 4 pg m−3.

Tomographic capabilities of the new GEM based SXR diagnostic of WEST

Science.gov (United States)

Jardin, A.; Mazon, D.; O'Mullane, M.; Mlynar, J.; Loffelmann, V.; Imrisek, M.; Chernyshova, M.; Czarski, T.; Kasprowicz, G.; Wojenski, A.; Bourdelle, C.; Malard, P.

2016-07-01

The tokamak WEST (Tungsten Environment in Steady-State Tokamak) will start operating by the end of 2016 as a test bed for the ITER divertor components in long pulse operation. In this context, radiative cooling of heavy impurities like tungsten (W) in the Soft X-ray (SXR) range [0.1 keV; 20 keV] is a critical issue for the plasma core performances. Thus reliable tools are required to monitor the local impurity density and avoid W accumulation. The WEST SXR diagnostic will be equipped with two new GEM (Gas Electron Multiplier) based poloidal cameras allowing to perform 2D tomographic reconstructions in tunable energy bands. In this paper tomographic capabilities of the Minimum Fisher Information (MFI) algorithm developed for Tore Supra and upgraded for WEST are investigated, in particular through a set of emissivity phantoms and the standard WEST scenario including reconstruction errors, influence of noise as well as computational time.

The application of a monolithic triphenylphosphine reagent for conducting Ramirez gem-dibromoolefination reactions in flow.

Science.gov (United States)

Roper, Kimberley A; Berry, Malcolm B; Ley, Steven V

2013-01-01

The application of a monolithic form of triphenylphosphine to the Ramirez gem-dibromoolefination reaction using flow chemistry techniques is reported. A variety of gem-dibromides were synthesised in high purity and excellent yield following only removal of solvent and no further off-line purification. It is also possible to perform the Appel reaction using the same monolith and the relationship between the mechanisms of the two reactions is discussed.

Gains in the Education of Mathematics and Science GEMS: Teaching Robotics to High School Students

Science.gov (United States)

2013-01-01

find amusing but that we find of less educational value, like having the robots say comical things. Those who have more teaching time would doubtless...Gains in the Education of Mathematics and Science GEMS: Teaching Robotics to High School Students by Edward M. Measure and Edward Creegan...TR-6220 January 2013 Gains in the Education of Mathematics and Science (GEMS): Teaching Robotics to High School Students Edward M

First measurements with new high-resolution gadolinium-GEM neutron detectors

CERN Document Server

Pfeiffer, Dorothea; Birch, Jens; Etxegarai, Maddi; Hall-Wilton, Richard; Höglund, Carina; Hultman, Lars; Llamas-Jansa, Isabel; Oliveri, Eraldo; Oksanen, Esko; Robinson, Linda; Ropelewski, Leszek; Schmidt, Susann; Streli, Christina; Thuiner, Patrik

2016-05-17

European Spallation Source instruments like the macromolecular diffractometer, NMX, require an excellent neutron detection efficiency, high-rate capabilities, time resolution, and an unprecedented spatial resolution in the order of a few hundred micrometers over a wide angular range of the incoming neutrons. For these instruments solid converters in combination with Micro Pattern Gaseous Detectors (MPGDs) are a promising option. A GEM detector with gadolinium converter was tested on a cold neutron beam at the IFE research reactor in Norway. The {\\mu}TPC analysis, proven to improve the spatial resolution in the case of $^{10}$B converters, is extended to gadolinium based detectors. For the first time, a Gd-GEM was successfully operated to detect neutrons with an estimated efficiency of 10% at a wavelength of 2 {\\AA} and a position resolution better than 350 {\\mu}m.

Hard assets : The return of rare diamonds and gems

NARCIS (Netherlands)

Renneboog, Luc; Spaenjers, Christophe; Grynberg, Roman; Mbayi, Letsema

This note examines the investment performance of diamonds and other gems (sapphires, rubies, and emeralds) over the period 1999–2010, using a novel data set of auction transactions. Over our time frame, the annualized real USD returns for white and colored diamonds equaled 6.4% and 2.9%,

Hard assets : The return on rare diamonds and gems

NARCIS (Netherlands)

Renneboog, L.D.R.; Spaenjers, C.

2012-01-01

This note examines the investment performance of diamonds and other gems (sapphires, rubies, and emeralds) over the period 1999–2010, using a novel data set of auction transactions. Over our time frame, the annualized real USD returns for white and colored diamonds equaled 6.4% and 2.9%,

Hard Assets : The Returns on Rare Diamonds and Gems

NARCIS (Netherlands)

Renneboog, L.D.R.; Spaenjers, C.

2011-01-01

This paper examines the investment performance of diamonds and other gems (sapphires, rubies, and emeralds) over the period 1999-2010, using a novel data set of auction transactions. Between 1999 and 2010, the annualized real USD returns for white and colored diamonds equaled 6.4% and 2.9%,

Developments and the preliminary tests of Resistive GEMs manufactured by a screen printing technology

CERN Document Server

Agócs, G; Oliveira, R; Martinego, P; Peskov, Vladimir; Pietropaolo, P; Picchi, P

2008-01-01

We report promising initial results obtained with new resistive-electrode GEM (RETGEM) detectors manufactured, for the first time, using screen printing technology. These new detectors allow one to reach gas gains nearly as high as with ordinary GEM-like detectors with metallic electrodes; however, due to the high resistivity of its electrodes the RETGEM, in contrast to ordinary hole-type detectors, has the advantage of being fully spark protected. We discovered that RETGEMs can operate stably and at high gains in noble gases and in other badly quenched gases, such as mixtures of noble gases with air and in pure air; therefore, a wide range of practical applications, including dosimetry and detection of dangerous gases, is foreseeable. To promote a better understanding of RETGEM technology some comparative studies were completed with metallic-electrode thick GEMs. A primary benefit of these new RETGEMs is that the screen printing technology is easily accessible to many research laboratories. This accessibilit...

The application of a monolithic triphenylphosphine reagent for conducting Ramirez gem-dibromoolefination reactions in flow

Directory of Open Access Journals (Sweden)

Kimberley A. Roper

2013-09-01

Full Text Available The application of a monolithic form of triphenylphosphine to the Ramirez gem-dibromoolefination reaction using flow chemistry techniques is reported. A variety of gem-dibromides were synthesised in high purity and excellent yield following only removal of solvent and no further off-line purification. It is also possible to perform the Appel reaction using the same monolith and the relationship between the mechanisms of the two reactions is discussed.

Energy calibration of a GEM-TPC with Kr83m

Energy Technology Data Exchange (ETDEWEB)

Schmitz, Roman [Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn (Germany); Collaboration: GEM-TPC-Collaboration

2013-07-01

A Time Projection Chamber (TPC) with Gas Electron Multiplier (GEM) readout has been developed with an inner/outer radius of 5/15 cm and a total drift length of 73 cm. It has been used as an inner tracking upgrade for the FOPI experiment at GSI and is planned as a future upgrade to the CBELSA/TAPS experiment. A radioactive {sup 83m}Kr source has been produced and integrated into the setup in order to perform an accurate channel-wise relative gain calibration and monitor gain stability to achieve optimal dE/dx resolution. Its gaseous form makes it perfectly suitable for this purpose allowing a full coverage of the readout plane and providing a wide energy range of conversion peaks. Also its half-life of 1.83 h allows for normal detector operation after a short flushing period of several hours. Calibration method and measured energy resolution for different gas mixtures which have been compared to simulation results are presented in this talk. Also first results on gain stability and pressure/temperature-dependence are shown.

GEM detector performance with innovative micro-TPC readout in high magnetic field

Directory of Open Access Journals (Sweden)

Garzia I.

2018-01-01

Full Text Available Gas detector development is one of the pillars of the research in fundamental physics. Since several years, a new concept of detectors, called Micro Pattern Gas Detector (MPGD, allowed to overcome several problems related to other types of commonly used detectors, like drift chamber and micro strips detectors, reducing the rate of discharges and providing better radiation tolerance. Among the most used MPGDs are the Gas Electron Multipliers (GEMs. Invented by Sauli in 1997, nowadays GEMs have become an important reality for particle detectors in high energy physics. Commonly deployed as fast timing detectors and triggers, their fast response, high rate capability and high radiation hardness make them also suitable as tracking detectors. The readout scheme is one of the most important features in tracking technology. Analog readout based on the calculation of the center of gravity technique allows to overcome the limit imposed by digital pads, whose spatial resolution is limited by the pitch dimensions. However, the presence of high external magnetic fields can distort the electronic cloud and affect the performance. The development of the micro-TPC reconstruction method brings GEM detectors into a new prospective, improving significantly the spatial resolutionin presence of high magnetic fields. This innovative technique allows to reconstruct the 3-dimensional particle position, as Time Projection Chamber, but within a drift gap of a few millimeters. In these report, the charge centroid and micro-TPC methods are described in details. We discuss the results of several test beams performed with planar chambers in magnetic field. These results are one of the first developments of micro-TPC technique for GEM detectors, which allows to reach unprecedented performance in a high magnetic field of 1 T.

GEM detector performance with innovative micro-TPC readout in high magnetic field

Science.gov (United States)

Garzia, I.; Alexeev, M.; Amoroso, A.; Baldini Ferroli, R.; Bertani, M.; Bettoni, D.; Bianchi, F.; Calcaterra, A.; Canale, N.; Capodiferro, M.; Cassariti, V.; Cerioni, S.; Chai, J. Y.; Chiozzi, S.; Cibinetto, G.; Cossio, F.; Cotta Ramusino, A.; De Mori, F.; Destefanis, M.; Dong, J.; Evangelisti, F.; Evangelisti, F.; Farinelli, R.; Fava, L.; Felici, G.; Fioravanti, E.; Gatta, M.; Greco, M.; Lavezzi, L.; Leng, C. Y.; Li, H.; Maggiora, M.; Malaguti, R.; Marcello, S.; Melchiorri, M.; Mezzadri, G.; Mignone, M.; Morello, G.; Pacetti, S.; Patteri, P.; Pellegrino, J.; Pelosi, A.; Rivetti, A.; Rolo, M. D.; Savrié, M.; Scodeggio, M.; Soldani, E.; Sosio, S.; Spataro, S.; Tskhadadze, E.; Verma, S.; Wheadon, R.; Yan, L.

2018-01-01

Gas detector development is one of the pillars of the research in fundamental physics. Since several years, a new concept of detectors, called Micro Pattern Gas Detector (MPGD), allowed to overcome several problems related to other types of commonly used detectors, like drift chamber and micro strips detectors, reducing the rate of discharges and providing better radiation tolerance. Among the most used MPGDs are the Gas Electron Multipliers (GEMs). Invented by Sauli in 1997, nowadays GEMs have become an important reality for particle detectors in high energy physics. Commonly deployed as fast timing detectors and triggers, their fast response, high rate capability and high radiation hardness make them also suitable as tracking detectors. The readout scheme is one of the most important features in tracking technology. Analog readout based on the calculation of the center of gravity technique allows to overcome the limit imposed by digital pads, whose spatial resolution is limited by the pitch dimensions. However, the presence of high external magnetic fields can distort the electronic cloud and affect the performance. The development of the micro-TPC reconstruction method brings GEM detectors into a new prospective, improving significantly the spatial resolutionin presence of high magnetic fields. This innovative technique allows to reconstruct the 3-dimensional particle position, as Time Projection Chamber, but within a drift gap of a few millimeters. In these report, the charge centroid and micro-TPC methods are described in details. We discuss the results of several test beams performed with planar chambers in magnetic field. These results are one of the first developments of micro-TPC technique for GEM detectors, which allows to reach unprecedented performance in a high magnetic field of 1 T.

A GEM-TPC prototype with low-Noise highly integrated front-end electronics for linear collider studies

CERN Document Server

Kappler, Steffen; Kaminski, Jochen; Ledermann, Bernhard; Müller, Thomas; Ronan, Michael T; Ropelewski, Leszek; Sauli, Fabio; Settles, Ronald

2004-01-01

Connected to the linear collider project, studies on the readout of time projection chambers (TPCs) based on the gas electron multiplier (GEM) are ongoing. Higher granularity and intrinsically suppressed ion feedback are the major advantages of this technology. After a short discussion of these issues, we present the design of a small and very flexible TPC prototype, whose cylindrical drift volume can be equipped with endcaps of different gas detector types. An endcap with multi-GEM readout is currently set up and successfully operated with a low-noise highly integrated front-end electronics. We discuss results of measurements with this system in high intensity particle beams at CERN, where 99.3 plus or minus 0.2% single-pad-row efficiency could be achieved at an effective gain of 2.5 multiplied by 10**3 only, and spatial resolutions down to 63 plus or minus 3 mum could be demonstrated. Finally, these results are extrapolated to the high magnetic field in a linear collider TPC. 5 Refs.

The Gem Infrasound Logger and Custom-Built Instrumentation

International Nuclear Information System (INIS)

Anderson, Jacob F.; Ronan, Timothy J.

2017-01-01

Here, we designed, built, and recorded data with a custom infrasound logger (referred to as the Gem) that is inexpensive, portable, and easy to use. We also describe its design process, qualities, and applications in this article. Field instrumentation is a key element of geophysical data collection, and the quantity and quality of data that can be recorded is determined largely by the characteristics of the instruments used. Geophysicists tend to rely on commercially available instruments, which suffice for many important types of fieldwork. However, commercial instrumentation can fall short in certain roles, which motivates the development of custom sensors and data loggers. Particularly, we found existing data loggers to be expensive and inconvenient for infrasound campaigns, and developed the Gem infrasound logger in response. In this article, we discuss development of this infrasound logger and the various uses found for it, including projects on volcanoes, high-altitude balloons, and rivers. Further, we demonstrate that when needed, scientists can feasibly design and build their own specialized instruments, and that doing so can enable them to record more and better data at a lower cost.

Some Interesting Mathematical Gems -R-ES-ONANCE--Isep-te ...

Indian Academy of Sciences (India)

Same thing applies to results cho- sen here" I shall not refer to gems like Godel's incom- plete theorern or the ... ematics, theoretical computer science, probability and statistics. Based on an invited talk dedi- cated to Dr P L Bhatnagar,. Founder Professor of the Math- ematics Department (then known as Department of Ap-.

First results with the general equilibrium model GEM-E3 Switzerland

International Nuclear Information System (INIS)

Bahn, O.; Frei, C.

2000-01-01

The GEM-E3 model has been implemented and applied for Switzerland. It has been in particular used to assess an ecological tax reform in Switzerland. Results of this analysis are presented here. (author)

Atmospheric gaseous elemental mercury (GEM concentrations and mercury depositions at a high-altitude mountain peak in south China

Directory of Open Access Journals (Sweden)

X. W. Fu

2010-03-01

Full Text Available China is regarded as the largest contributor of mercury (Hg to the global atmospheric Hg budget. However, concentration levels and depositions of atmospheric Hg in China are poorly known. Continuous measurements of atmospheric gaseous elemental mercury (GEM were carried out from May 2008 to May 2009 at the summit of Mt. Leigong in south China. Simultaneously, deposition fluxes of THg and MeHg in precipitation, throughfall and litterfall were also studied. Atmospheric GEM concentrations averaged 2.80±1.51 ng m⁻³, which was highly elevated compared to global background values but much lower than semi-rural and industrial/urban areas in China. Sources identification indicates that both regional industrial emissions and long range transport of Hg from central, south and southwest China were corresponded to the elevated GEM level. Seasonal and diurnal variations of GEM were observed, which reflected variations in source intensity, deposition processes and meteorological factors. Precipitation and throughfall deposition fluxes of THg and MeHg in Mt. Leigong were comparable or lower compared to those reported in Europe and North America, whereas litterfall deposition fluxes of THg and MeHg were higher compared to Europe and North America. This highlights the importance of vegetation to Hg atmospheric cycling. In th remote forest ecosystem of China, deposition of GEM via uptake of foliage followed by litterfall was very important for the depletion of atmospheric Hg. Elevated GEM level in ambient air may accelerate the foliar uptake of Hg through air which may partly explain the elevated litterfall deposition fluxes of Hg observed in Mt. Leigong.

Construction of the TH-GEM detector components for metrology of low energy ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Silva, N.F.; Castro, M.C.; Caldas, L.V.E., E-mail: nsilva@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Silva, T.F.; Luz, H. Natal da [Universidade de São Paulo (IF/USP), São Paulo, SP (Brazil). Instituto de Física

2017-07-01

The Gas Electron Multiplier (GEM) detector was originally proposed as a position sensitive detector to determine trajectories of particles prevenient from high energy collisions. In order to study the potential of TH-GEM type detectors in dosimetric applications for low energy X-rays, specifically for the mammography standard qualities, it was proposed to construct a prototype with characteristics suitable for such use. In this work the general, structural and material parameters applicable to the necessary conditions were defined, establishing the process of construction of the components of a prototype. (author)

Construction of the TH-GEM detector components for metrology of low energy ionizing radiation

International Nuclear Information System (INIS)

Silva, N.F.; Castro, M.C.; Caldas, L.V.E.; Silva, T.F.; Luz, H. Natal da

2017-01-01

The Gas Electron Multiplier (GEM) detector was originally proposed as a position sensitive detector to determine trajectories of particles prevenient from high energy collisions. In order to study the potential of TH-GEM type detectors in dosimetric applications for low energy X-rays, specifically for the mammography standard qualities, it was proposed to construct a prototype with characteristics suitable for such use. In this work the general, structural and material parameters applicable to the necessary conditions were defined, establishing the process of construction of the components of a prototype. (author)

Construction of the TH-GEM detector components for metrology of low energy ionizing radiation

Science.gov (United States)

Silva, N. F.; Silva, T. F.; Castro, M. C.; Natal da Luz, H.; Caldas, L. V. E.

2018-03-01

The Gas Electron Multiplier (GEM) detector was originally proposed as a position sensitive detector to determine trajectories of particles prevenient from high-energy collisions. In order to study the potential of TH-GEM type detectors in dosimetric applications for low energy X-rays, specifically for the mammography standard qualities, it was proposed to construct a prototype with characteristics suitable for such use. In this work the general, structural and material parameters applicable to the necessary conditions were defined, establishing the process of construction of the components of a prototype.

Systematic measurements of the gain and the energy resolution of single and double mask GEM detectors

International Nuclear Information System (INIS)

Biswas, S.; Schmidt, D.J.; Abuhoza, A.; Frankenfeld, U.; Garabatos, C.; Hehner, J.; Kleipa, V.; Morhardt, T.; Schmidt, C.J.; Schmidt, H.R.; Wiechula, J.

2016-01-01

Systematic studies on the gain and the energy resolution have been carried out by varying the voltage across the GEM foils for both single mask and double mask triple GEM detector prototypes. Variation of the gain and the energy resolution has also been measured by varying either the drift voltage, transfer voltage and induction voltage keeping other voltages constant. The results of the systematic measurements have been presented.

Fast drift CRID with GEM

CERN Document Server

Vavra, J; McCulloch, M; Stiles, P; Sauli, Fabio

1999-01-01

The only available technique at the present time, to perform particle identification up to 40-50 GeV/c in a 4 pi solenoidal geometry using the Cherenkov ring imaging method is the use of gaseous detectors filled with either TMAE or TEA photocathodes, and a combination of the gaseous, and solid or liquid radiators. If one would consider building such a device, one may want to investigate alternative methods of building a single-electron detector. This paper investigates the feasibility of using the GEM together with a simple MWPC detector employing 33 mu m diameter carbon wires to obtain a second coordinate. The results are compared to the CRID single-electron detector.

Study of reconstruction methods for a time projection chamber with GEM gas amplification system

Energy Technology Data Exchange (ETDEWEB)

Diener, R.

2006-12-15

A new e{sup +}e{sup -} linear collider with an energy range up to 1TeV is planned in an international collaboration: the International Linear Collider (ILC). This collider will be able to do precision measurements of the Higgs particle and of physics beyond the Standard Model. In the Large Detector Concept (LDC) - which is one proposal for a detector at the ILC - a Time Projection Chamber (TPC) is foreseen as the main tracking device. To meet the requirements on the resolution and to be able to work in the environment at the ILC, the application of new gas amplification technologies in the TPC is necessary. One option is an amplification system based on Gas Electron Multipliers (GEMs). Due to the - in comparison with older technologies - small spatial width of the signals, this technology poses new requirements on the readout structures and the reconstruction methods. In this work, the performance and the systematics of different reconstruction methods have been studied, based on data measured with a TPC prototype in high magnetic fields of up to 4T and data from a Monte Carlo simulation. The latest results of the achievable point resolution are presented and their limitations have been investigated. (orig.)

Study of reconstruction methods for a time projection chamber with GEM gas amplification system

International Nuclear Information System (INIS)

Diener, R.

2006-12-01

A new e + e - linear collider with an energy range up to 1TeV is planned in an international collaboration: the International Linear Collider (ILC). This collider will be able to do precision measurements of the Higgs particle and of physics beyond the Standard Model. In the Large Detector Concept (LDC) - which is one proposal for a detector at the ILC - a Time Projection Chamber (TPC) is foreseen as the main tracking device. To meet the requirements on the resolution and to be able to work in the environment at the ILC, the application of new gas amplification technologies in the TPC is necessary. One option is an amplification system based on Gas Electron Multipliers (GEMs). Due to the - in comparison with older technologies - small spatial width of the signals, this technology poses new requirements on the readout structures and the reconstruction methods. In this work, the performance and the systematics of different reconstruction methods have been studied, based on data measured with a TPC prototype in high magnetic fields of up to 4T and data from a Monte Carlo simulation. The latest results of the achievable point resolution are presented and their limitations have been investigated. (orig.)

Dijk- en oeverval aan den cal. Willem Annapolder (Gem. Kapelle)

NARCIS (Netherlands)

Verhagen, H.J.

1936-01-01

Foto's van de aanleg van de dijk- en oeverval aan den cal. Willem Annapolder (Gem. Kapelle) 3. Linkerhelft dijkval Willem Annapolder. 30 Dec. 1936 4. Rechtehelft dijkval Willem Annapolder. 30 Dec. 1936 5. Overzicht dijkval Willem Annaolder. 30 Dec. 1936 6. Kleikisting binnendijks aangebacht. 14/15

Characterization of multilayer Thick-GEM geometries as 10B converters aiming thermal neutron detection

Directory of Open Access Journals (Sweden)

Natal da Luz H.

2018-01-01

Full Text Available Boron-based thermal neutron detectors have recently regained some attention from the instrumentation community as a strong alternative to helium-3 detectors. From the existing concepts exploiting boron layers in position sensitive detectors, the Cascade [1] is the one that takes full advantage of the 2D capabilities of gaseous detectors, with the position resolution not limited by the architecture of the detector. In this work, a proposal for the Cascade detector, based on Thick-GEMs is presented, together with some preliminary studies of the suitable pitch that optimizes the neutron conversion efficiency, while keeping the collection efficiency intact. The characterization of Thick-GEM prototypes produced in Brazil with hole pitch from 0.75 to 3 mm shows that these devices already present a stable performance at low gains, also resulting in fair energy resolution, when cascaded with a standard KaptonTM 50 µm GEM. Results of the first attempts of boron film depositions with Ion Beam Assisted Deposition and characterization by Ion Beam Analysis are also presented.

Characterization of multilayer Thick-GEM geometries as 10B converters aiming thermal neutron detection

Science.gov (United States)

Natal da Luz, H.; Souza, F. A.; Moralles, M.; Carlin, N.; Oliveira, R. A. N.; Bregant, M.; Suaide, A. A. P.; Chubaci, J. F. D.; Matsuoka, M.; Silva, T. F.; Moro, M. V.; Rodrigues, C. L.; Munhoz, M. G.

2018-02-01

Boron-based thermal neutron detectors have recently regained some attention from the instrumentation community as a strong alternative to helium-3 detectors. From the existing concepts exploiting boron layers in position sensitive detectors, the Cascade [1] is the one that takes full advantage of the 2D capabilities of gaseous detectors, with the position resolution not limited by the architecture of the detector. In this work, a proposal for the Cascade detector, based on Thick-GEMs is presented, together with some preliminary studies of the suitable pitch that optimizes the neutron conversion efficiency, while keeping the collection efficiency intact. The characterization of Thick-GEM prototypes produced in Brazil with hole pitch from 0.75 to 3 mm shows that these devices already present a stable performance at low gains, also resulting in fair energy resolution, when cascaded with a standard KaptonTM 50 µm GEM. Results of the first attempts of boron film depositions with Ion Beam Assisted Deposition and characterization by Ion Beam Analysis are also presented.

A hydrological prediction system based on the SVS land-surface scheme: efficient calibration of GEM-Hydro for streamflow simulation over the Lake Ontario basin

Directory of Open Access Journals (Sweden)

É. Gaborit

2017-09-01

Full Text Available This work explores the potential of the distributed GEM-Hydro runoff modeling platform, developed at Environment and Climate Change Canada (ECCC over the last decade. More precisely, the aim is to develop a robust implementation methodology to perform reliable streamflow simulations with a distributed model over large and partly ungauged basins, in an efficient manner. The latest version of GEM-Hydro combines the SVS (Soil, Vegetation and Snow land-surface scheme and the WATROUTE routing scheme. SVS has never been evaluated from a hydrological point of view, which is done here for all major rivers flowing into Lake Ontario. Two established hydrological models are confronted to GEM-Hydro, namely MESH and WATFLOOD, which share the same routing scheme (WATROUTE but rely on different land-surface schemes. All models are calibrated using the same meteorological forcings, objective function, calibration algorithm, and basin delineation. GEM-Hydro is shown to be competitive with MESH and WATFLOOD: the NSE  √  (Nash–Sutcliffe criterion computed on the square root of the flows is for example equal to 0.83 for MESH and GEM-Hydro in validation on the Moira River basin, and to 0.68 for WATFLOOD. A computationally efficient strategy is proposed to calibrate SVS: a simple unit hydrograph is used for routing instead of WATROUTE. Global and local calibration strategies are compared in order to estimate runoff for ungauged portions of the Lake Ontario basin. Overall, streamflow predictions obtained using a global calibration strategy, in which a single parameter set is identified for the whole basin of Lake Ontario, show accuracy comparable to the predictions based on local calibration: the average NSE  √  in validation and over seven subbasins is 0.73 and 0.61, respectively for local and global calibrations. Hence, global calibration provides spatially consistent parameter values, robust performance at gauged locations, and reduces the

A hydrological prediction system based on the SVS land-surface scheme: efficient calibration of GEM-Hydro for streamflow simulation over the Lake Ontario basin

Science.gov (United States)

Gaborit, Étienne; Fortin, Vincent; Xu, Xiaoyong; Seglenieks, Frank; Tolson, Bryan; Fry, Lauren M.; Hunter, Tim; Anctil, François; Gronewold, Andrew D.

2017-09-01

This work explores the potential of the distributed GEM-Hydro runoff modeling platform, developed at Environment and Climate Change Canada (ECCC) over the last decade. More precisely, the aim is to develop a robust implementation methodology to perform reliable streamflow simulations with a distributed model over large and partly ungauged basins, in an efficient manner. The latest version of GEM-Hydro combines the SVS (Soil, Vegetation and Snow) land-surface scheme and the WATROUTE routing scheme. SVS has never been evaluated from a hydrological point of view, which is done here for all major rivers flowing into Lake Ontario. Two established hydrological models are confronted to GEM-Hydro, namely MESH and WATFLOOD, which share the same routing scheme (WATROUTE) but rely on different land-surface schemes. All models are calibrated using the same meteorological forcings, objective function, calibration algorithm, and basin delineation. GEM-Hydro is shown to be competitive with MESH and WATFLOOD: the NSE √ (Nash-Sutcliffe criterion computed on the square root of the flows) is for example equal to 0.83 for MESH and GEM-Hydro in validation on the Moira River basin, and to 0.68 for WATFLOOD. A computationally efficient strategy is proposed to calibrate SVS: a simple unit hydrograph is used for routing instead of WATROUTE. Global and local calibration strategies are compared in order to estimate runoff for ungauged portions of the Lake Ontario basin. Overall, streamflow predictions obtained using a global calibration strategy, in which a single parameter set is identified for the whole basin of Lake Ontario, show accuracy comparable to the predictions based on local calibration: the average NSE √ in validation and over seven subbasins is 0.73 and 0.61, respectively for local and global calibrations. Hence, global calibration provides spatially consistent parameter values, robust performance at gauged locations, and reduces the complexity and computation burden of the

Ion space-charge effects in multi-GEM detectors: challenges and possible solutions for future applications

CERN Document Server

AUTHOR|(CDS)2079251; Streli, Christina

Gaseous Electron Multiplier (GEM) detectors are well known both for stable operation under irradiation with high particle fluxes and high achievable effective gains. The aim of this thesis is two-fold: to investigate the limits of GEM detector operation due to space-charge effects, and to develop a means to reduce the magnitude of the observed effects and thus extend those limitations. The first part of the thesis presents a comprehensive study of the intrinsic limits of triple-GEM detectors under exposure to very high fluxes of soft X-rays or operation at very large effective gains. The behaviour of the effective gain, ion back-flow and the pulse-height spectra is explained in terms of the movement and accumulation of positive ions throughout the detector volume, resulting in distortions of the transfer and amplification fields. Numerical computations, and measurements on double-stage and single-stage detectors confirm the model describing the observed effects. Discussions on ways to extend the limits of gas...

GEM-AQ, an on-line global multiscale chemical weather modelling system: model description and evaluation of gas phase chemistry processes

Directory of Open Access Journals (Sweden)

J. W. Kaminski

2008-06-01

Full Text Available Tropospheric chemistry and air quality processes were implemented on-line in the Global Environmental Multiscale weather prediction model. The integrated model, GEM-AQ, was developed as a platform to investigate chemical weather at scales from global to urban. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module with 5 aerosols types. All tracers are advected using the semi-Lagrangian scheme native to GEM. The vertical transport includes parameterized subgrid-scale turbulence and large scale deep convection. Dry deposition is included as a flux boundary condition in the vertical diffusion equation. Wet deposition of gas-phase species is treated in a simplified way, and only below-cloud scavenging is considered. The emissions used include yearly-averaged anthropogenic, and monthly-averaged biogenic, ocean, soil, and biomass burning emission fluxes, as well as NO_x from lightning. In order to evaluate the ability to simulate seasonal variations and regional distributions of trace gases such as ozone, nitrogen dioxide and carbon monoxide, the model was run for a period of five years (2001–2005 on a global uniform 1.5°×1.5° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. Model results were compared with observations from satellites, aircraft measurement campaigns and balloon sondes. We find that GEM-AQ is able to capture the spatial details of the chemical fields in the middle and lower troposphere. The modelled ozone consistently shows good agreement with observations, except over tropical oceans. The comparison of carbon monoxide and nitrogen dioxide with satellite measurements emphasizes the need for more accurate, year-specific emissions fluxes for biomass burning and anthropogenic sources. Other species also compare well with available observations.

Control and supervision of a time projection chamber with GEM readout; Steuerung und Ueberwachung einer Zeitprojektionskammer mit GEM-Auslese

Energy Technology Data Exchange (ETDEWEB)

Kaiser, David

2014-02-03

To get a deeper understanding of the structure of nucleons and the strong interaction binding the constituents inside, the CBELSA/TAPS experiment investigates the resonance spectrum of baryons by meson photoproduction within the scope of the SFB/TRR 16 ''Subnuclear Structure of Matter''. In order to support and expand the physical program, the existing Inner Detector will be replaced by a Time Projection Chamber (TPC) within the next few years. This allows for the detection of charged reaction channels, which can't be measured with the CBELSA/TAPS experiment up to now, as well as for particle identification from the specific energy loss. A First prototype with GEM foils for charge amplification in front of the readout plane and suitable size for the CBELSA/TAPS experiment was built in collaboration with the TU Munich, the detector laboratory of the GSI in Darmstadt and the Stefan-Meyer-Institute of the University Vienna. The TPC has been commissioned successfully within the FOPI experiment at the GSI during several test beam campaigns. Additionally, systematic studies have been carried out with a smaller Test-TPC using a TestBench providing an accurate external track definition. As the electron drift velocity in the TPC volume is a crucial parameter for the exact track reconstruction, detailed simulations of the drift velocity and its dependency on external parameters, such as drift voltage, pressure, gas flow or temperature, have been carried out. The results of these simulations recommend a constant monitoring of all examined parameters to allow a reasonable use of the simulated drift velocities. For this purpose, and to ensure a safe and stable operation of the TPCs and the other detectors on the TestBench, the required hardware, the control software based on a data base and a graphical user interface were designed and constructed as the main part of this work. With this so-called SlowControl, it was possible to measure, control and

FAKTOR-FAKTOR YANG MEMPENGARUHI AKTIVITAS KEWIRAUSAHAAN DI KOTA SURABAYA DAN KOTA DENPASAR HASIL GEM 2013

Directory of Open Access Journals (Sweden)

Yogo Aryo Jatmiko

2018-01-01

Full Text Available Penelitian ini bertujuan untuk mengetahui faktor-faktor yang mempengaruhi aktivitas kewirausahaan di kota Surabaya dan kota Denpasar berdasarkan faktor-faktor: knowledge of other entrepeneurs, perception of opportunities, perception of self-capabilities dan fear failure dengan variabel jenis kelamin (gender sebagai variabel kontrol. Data yang digunakan adalah data dari global entrepeneurship monitor (GEM. Dalam studi ini, data yang digunakan adalah data cross-sectional untuk survei tahun 2013, baik untuk kota Surabaya maupun kota Denpasar. Model yang digunakan adalah analisis regresi logistik sequential untuk memprediksi keterlibatan faktor dengan aktivitas kewirausahaan. Kota Surabaya tidak signifikan dipengaruhi oleh knowledge of other entrepeneurs. Untuk kota Denpasar, variabel perception of self-capabilities dan fear to fail tidak signifikan mempengaruhi aktivitas kewirausahaan di kota Denpasar. Variabel gender berpengaruh secara signifikan di kota Surabaya, tetapi tidak di kota Denpasar.

International Genetically Engineered Machine (iGEM) Competition

CSIR Research Space (South Africa)

Sparrow, RW

2010-07-01

Full Text Available . At this meeting it was requested that the CSIR act as the administrative co-ordinating arm of the team. Following from this meeting a brochure was produced advertising the iGEM competition inside Wits and for Honours student nominations to be team members.... The academic year in South Africa commences in February. By late February 2010 student nominations had been received from which the supervisors selected the team members. The first team meeting was held on 5th March 2010. After which the team...

The GEM Theory of the Unification of Gravitation and Electro-Magnetism

Science.gov (United States)

Brandenburg, J. E.

2012-01-01

The GEM (Gravity Electro-Magnetism), theory is presented as an alloy of Sakharov and Kaluza-Klein approaches to field unification. GEM uses the concept of gravity fields as Poynting fields to postulate that the non-metric portion of the EM stress tensor becomes the metric tensor in strong fields leading to "self-censorship". Covariant formulation of the GEM theory is accomplished through definition of the spacetime metric tensor as a portion of the EM stress tensor normalized by its own trace: gab = 4(FcaFcb )/(FabFab), it is found that this results in a massless ground state vacuum and a Newtonian gravitation potential f=1/2 E2/B2 =GM/r , where E, B and F are part of the vacuum Zero Point Fluctuation (ZPF) and M and r are the mass and distance from the center of a gravitating body and G is the Newton gravitation constant. It is found that a Lorentz flat-space metric is recovered in the limit of a vacuum full spectrum ZPF. The vacuum ZPF energy and vacuum quantities G, h, c, gives birth to particles quantities mp, me, e,-e in a process triggered by the appearance of the Kaluza-Klein fifth dimension, where also the EM and gravity forces split from each other in a process correlated to the splitting apart of protons and electrons. The separate appearance of the proton and electron occurs as the splitting of a light-like spacetime interval of zero-length into a finite space-like portion containing three subdimensions identified with the quarks and a time-like portion identified with the electron. The separation of mass with charge for the electron and proton pair comes about from a U(1) symmetry with a rotation in imaginary angle. A logarithmic variation of charge with mass for the proton-electron pair results and leads to the formula ln(ro/rp) = s, where s = (mp/me)1/2 , where mp and me are the electron and proton masses respectively and where ro =e2/moc2 , and where mo = (mpme)1/2 and where rp is the Planck length . This leads to the formula G=e2/mo2aexp(-2s)=6

[Construction of Lactobacillus rhamnosus GG particles surface display system].

Science.gov (United States)

Su, Runyu; Nie, Boyao; Yuan, Shengling; Tao, Haoxia; Liu, Chunjie; Yang, Bailiang; Wang, Yanchun

2017-01-25

To describe a novel particles surface display system which is consisted of gram-positive enhancer matrix (GEM) particles and anchor proteins for bacteria-like particles vaccines, we treated Lactobacillus rhamnosus GG bacteria with 10% heated-TCA for preparing GEM particles, and then identified the harvested GEM particles by electron microscopy, RT-PCR and SDS-PAGE. Meanwhile, Escherichia coli was induced to express hybrid proteins PA3-EGFP and P60-EGFP, and GEM particles were incubated with them. Then binding of anchor proteins were determined by Western blotting, transmission electron microscopy, fluorescence microscopy and spectrofluorometry. GEM particles preserved original size and shape, and proteins and DNA contents of GEM particles were released substantially. The two anchor proteins both had efficiently immobilized on the surface of GEM. GEM particles that were bounded by anchor proteins were brushy. The fluorescence of GEM particles anchoring PA3 was slightly brighter than P60, but the difference was not significant (P>0.05). GEM particles prepared from L. rhamnosus GG have a good binding efficiency with anchor proteins PA3-EGFP and P60-EGFP. Therefore, this novel foreign protein surface display system could be used for bacteria-like particle vaccines.

Aging measurements on triple-GEM detectors operated with $CF_{4}$-based gas mixtures

CERN Document Server

Alfonsi, M; De Simone, P; Murtas, F; Poli Lener, M P; Bonivento, W; Cardini, A; Raspino, D; Saitta, B; Pinci, D; Baccaro, S; 10.1016/j.nuclphysbps.2005.03.054

2006-01-01

We present the results of a global irradiation test of full size triple-GEM detectors operated with CF/sub 4/-based gas mixtures. This study has been performed in the framework of an R&D activity on detectors for the innermost region of the first muon station of the LHCb experiment. The prototypes have been irradiated at the Calliope facility of the ENEA-Casaccia with a high intensity 1.25 MeV detectors performances have been measured with X-rays and with a 3 Ge V pion beam at CERN. A SEM analysis on several samples of the detectors has been performed to complete the understanding of the physical processes occurring in a GEM detector during a strong irradiation.

Limits of a spatial resolution of the cascaded GEM based detectors

International Nuclear Information System (INIS)

Kudryavtsev, V.N.; Maltsev, T.V.; Shekhtman, L.I.

2017-01-01

Spatial resolution of tracking detectors based on GEM cascades is determined in the simulation and measured. The simulation includes GEANT4 implemented transport of high energy electrons with careful accounting for atomic relaxation processes including emission of fluorescent photons and Auger electrons and custom post-processing taking into account diffusion, gas amplification fluctuations, the distribution of signals over readout electrodes, electronics noise and particular algorithm of final coordinate calculation (centre-of-gravity algorithm). The simulation demonstrates that the minimum of the spatial resolution of about 10–20 μm can be achieved with a gas mixture of Ar-CO 2 (75%–25%) at a strip pitch in the range from 250 μm to 300 μm. At a larger pitch the resolution quickly degrades reaching 70–100 μm at a pitch of 450–500 μm. The reasons of such behavior are discussed and corresponding hypothesis is tested. Particularly, the effect of electron cloud modification due to a GEM operation is considered using the ANSYS and Garfield++ simulation programs. The detection efficiency and spatial resolution of low-material triple-GEM detectors for the DEUTERON facility at BINP are measured at the extracted beam facility of the VEPP-4M collider. One-coordinate resolution of two detectors for the DEUTERON facility is measured with a 2 GeV electron beam. The determined values of the detectors' spatial resolution is equal to 46.6 ± 0.1 μm and 38.5 ± 0.2 μm for orthogonal tracks in two detectors, respectively.

Limits of a spatial resolution of the cascaded GEM based detectors

Science.gov (United States)

Kudryavtsev, V. N.; Maltsev, T. V.; Shekhtman, L. I.

2017-06-01

Spatial resolution of tracking detectors based on GEM cascades is determined in the simulation and measured. The simulation includes GEANT4 implemented transport of high energy electrons with careful accounting for atomic relaxation processes including emission of fluorescent photons and Auger electrons and custom post-processing taking into account diffusion, gas amplification fluctuations, the distribution of signals over readout electrodes, electronics noise and particular algorithm of final coordinate calculation (centre-of-gravity algorithm). The simulation demonstrates that the minimum of the spatial resolution of about 10-20 μm can be achieved with a gas mixture of Ar-CO2 (75%-25%) at a strip pitch in the range from 250 μm to 300 μm. At a larger pitch the resolution quickly degrades reaching 70-100 μm at a pitch of 450-500 μm. The reasons of such behavior are discussed and corresponding hypothesis is tested. Particularly, the effect of electron cloud modification due to a GEM operation is considered using the ANSYS and Garfield++ simulation programs. The detection efficiency and spatial resolution of low-material triple-GEM detectors for the DEUTERON facility at BINP are measured at the extracted beam facility of the VEPP-4M collider. One-coordinate resolution of two detectors for the DEUTERON facility is measured with a 2 GeV electron beam. The determined values of the detectors' spatial resolution is equal to 46.6 ± 0.1 μm and 38.5 ± 0.2 μm for orthogonal tracks in two detectors, respectively.

Progress on The GEMS (Gravity Electro-Magnetism-Strong) Theory of Field Unification and Its Application to Space Problems

International Nuclear Information System (INIS)

Brandenburg, J. E.

2008-01-01

Progress on the GEMS (Gravity Electro-Magnetism-Strong), theory is presented as well as its application to space problems. The GEMS theory is now validated through the Standard Model of physics. Derivation of the value of the Gravitation constant based on the observed variation of α with energy: results in the formula G congruent with (ℎ/2π)c/M ηc 2 exp(-1/(1.61α)), where α is the fine structure constant,(ℎ/2π), is Planck's constant, c, is the speed of light, and M ηc is the mass of the η cc Charmonium meson that is shown to be identical to that derived from the GEM postulates. Covariant formulation of the GEM theory is now possible through definition of the spacetime metric tensor as a portion of the EM stress tensor normalized by its own trace: g ab = 4(F c a F cb )/(F ab F ab ), it is found that this results in a massless ground state vacuum and a Newtonian gravitation potential φ = 1/2 E 2 /B 2 . It is also found that a Lorentz or flat-space metric is recovered in the limit of a full spectrum ZPF

hpGEM -- A software framework for discontinuous Galerkin finite element methods

NARCIS (Netherlands)

Pesch, L.; Bell, A.; Sollie, W.E.H.; Ambati, V.R.; Bokhove, Onno; van der Vegt, Jacobus J.W.

2006-01-01

hpGEM, a novel framework for the implementation of discontinuous Galerkin finite element methods, is described. We present structures and methods that are common for many (discontinuous) finite element methods and show how we have implemented the components as an object-oriented framework. This

Serial data acquisition for GEM-2D detector

International Nuclear Information System (INIS)

Kolasinski, Piotr; Pozniak, Krzysztof T.; Czarski, Tomasz; Linczuk, Maciej; Byszuk, Adrian; Chernyshova, Maryna; Juszczyk, Bartlomiej; Kasprowicz, Grzegorz; Wojenski, Andrzej; Zabolotny, Wojciech; Zienkiewicz, Pawel; Mazon, Didier; Malard, Philippe; Herrmann, Albrecht; Vezinet, Didier

2014-01-01

This article debates about data fast acquisition and histogramming method for the X-ray GEM detector. The whole process of histogramming is performed by FPGA chips (Spartan-6 series from Xilinx). The results of the histogramming process are stored in an internal FPGA memory and then sent to PC. In PC data is merged and processed by MATLAB. The structure of firmware functionality implemented in the FPGAs is described. Examples of test measurements and results are presented. (authors)

Safety system status monitoring

International Nuclear Information System (INIS)

Lewis, J.R.; Morgenstern, M.H.; Rideout, T.H.; Cowley, P.J.

1984-03-01

The Pacific Northwest Laboratory has studied the safety aspects of monitoring the preoperational status of safety systems in nuclear power plants. The goals of the study were to assess for the NRC the effectiveness of current monitoring systems and procedures, to develop near-term guidelines for reducing human errors associated with monitoring safety system status, and to recommend a regulatory position on this issue. A review of safety system status monitoring practices indicated that current systems and procedures do not adequately aid control room operators in monitoring safety system status. This is true even of some systems and procedures installed to meet existing regulatory guidelines (Regulatory Guide 1.47). In consequence, this report suggests acceptance criteria for meeting the functional requirements of an adequate system for monitoring safety system status. Also suggested are near-term guidelines that could reduce the likelihood of human errors in specific, high-priority status monitoring tasks. It is recommended that (1) Regulatory Guide 1.47 be revised to address these acceptance criteria, and (2) the revised Regulatory Guide 1.47 be applied to all plants, including those built since the issuance of the original Regulatory Guide

Safety system status monitoring

Energy Technology Data Exchange (ETDEWEB)

Lewis, J.R.; Morgenstern, M.H.; Rideout, T.H.; Cowley, P.J.

1984-03-01

The Pacific Northwest Laboratory has studied the safety aspects of monitoring the preoperational status of safety systems in nuclear power plants. The goals of the study were to assess for the NRC the effectiveness of current monitoring systems and procedures, to develop near-term guidelines for reducing human errors associated with monitoring safety system status, and to recommend a regulatory position on this issue. A review of safety system status monitoring practices indicated that current systems and procedures do not adequately aid control room operators in monitoring safety system status. This is true even of some systems and procedures installed to meet existing regulatory guidelines (Regulatory Guide 1.47). In consequence, this report suggests acceptance criteria for meeting the functional requirements of an adequate system for monitoring safety system status. Also suggested are near-term guidelines that could reduce the likelihood of human errors in specific, high-priority status monitoring tasks. It is recommended that (1) Regulatory Guide 1.47 be revised to address these acceptance criteria, and (2) the revised Regulatory Guide 1.47 be applied to all plants, including those built since the issuance of the original Regulatory Guide.

Prototype sector magnets for the GeV electron microtron (GEM)

International Nuclear Information System (INIS)

Wehrle, R.B.; Norem, J.H.; Praeg, W.F.; Swanstrom, R.H.; Thompson, K.M.

1983-01-01

Three prototypes of the sector magnets for GeV Electon Microtron accelerators have been designed. One has been built and two are being constructed. The first is a full scale, 168 ton prototype for one-half of a 2 GeV Double Sided Microtron (DSM) sector magnet. The successful fabrication and testing of the pole pieces for this prototype has demonstrated that their required close tolerances for flatness and parallelism can be met. The second magnet is an approximate two-thirds scale model of one step at the low energy end of the hexatron sector magnet designed for the 4 GeV Electron Microtron (GEM). The measured fields demonstrate that the field falls off faster than an Enge-short-tail and error fields are at low levels and are controllable. A third prototype magnet exactly duplicates the full scale geometry of the first three full orbits of the GEM sector magnet from entrance to exit points. It will permit high precision measurements and corrections of field errors and verify the 3-D computer program, TOSCA

LHCb: A fast triple-GEM detector for high-rate charged-particle triggering

CERN Multimedia

2001-01-01

- GEM: Principle of Operation - Time Performances - Detector Prototypes and Test Setup - Gas Mixtures - Fields Optimisation - Vgem Optimisation Ar/CO2 (70/30) - Vgem Optimisation Ar/CO2/CF4 (60/20/20) - Time Distributions - Future Tests and Developments

Live event reconstruction in an optically read out GEM-based TPC

Science.gov (United States)

Brunbauer, F. M.; Galgóczi, G.; Gonzalez Diaz, D.; Oliveri, E.; Resnati, F.; Ropelewski, L.; Streli, C.; Thuiner, P.; van Stenis, M.

2018-04-01

Combining strong signal amplification made possible by Gaseous Electron Multipliers (GEMs) with the high spatial resolution provided by optical readout, highly performing radiation detectors can be realized. An optically read out GEM-based Time Projection Chamber (TPC) is presented. The device permits 3D track reconstruction by combining the 2D projections obtained with a CCD camera with timing information from a photomultiplier tube. Owing to the intuitive 2D representation of the tracks in the images and to automated control, data acquisition and event reconstruction algorithms, the optically read out TPC permits live display of reconstructed tracks in three dimensions. An Ar/CF4 (80/20%) gas mixture was used to maximize scintillation yield in the visible wavelength region matching the quantum efficiency of the camera. The device is integrated in a UHV-grade vessel allowing for precise control of the gas composition and purity. Long term studies in sealed mode operation revealed a minor decrease in the scintillation light intensity.

A TPC-like readout method for high precision muon-tracking using GEM-detectors

Energy Technology Data Exchange (ETDEWEB)

Flierl, Bernhard; Biebel, Otmar; Bortfeldt, Jonathan; Hertenberger, Ralf; Klitzner, Felix; Loesel, Philipp; Mueller, Ralph [Ludwig-Maximilians-Universitaet Muenchen (Germany); Zibell, Andre [Julius-Maximilians-Universitaet Wuerzburg (Germany)

2016-07-01

Gaseous electron multiplier (GEM) detectors are well suited for tracking of charged particles. Three dimensional tracking in a single layer can be achieved by application of a time-projection-chamber like readout mode (μTPC), if the drift time of the electrons is measured and the position dependence of the arrival time is used to calculate the inclination angle of the track. To optimize the tracking capabilities for ion tracks drift gas mixtures with low drift velocity have been investigated by measuring tracks of cosmic muons in a compact setup of four GEM-detectors of 100 x 100 x 6 mm{sup 3} active volume each and an angular acceptance of -25 to 25 . The setup consists of three detectors with two-dimensional strip readout layers of 0.4 mm pitch and one detector with a single strip readout layer of 0.25 mm pitch. All strips are readout by APV25 frontend boards and the amplification stage in the detectors consists of three GEM-foils. Tracks are reconstructed by the μTPC-method in one of the detectors and are then compared to the prediction from the other three detectors defined by the center of charge in every detector. We report our study of Argon and Helium based noble gas mixtures with carbon-dioxide as quencher.

Quality assurance of GEM foils in the framework of the TPC upgrade in the ALICE experiment

CERN Document Server

Ozcelik, Melih Arslan

2016-01-01

In the framework of the TPC upgrade of the ALICE Experiment, new readout chambers will be installed during the LHC long shutdown 2, which is scheduled to start in July 2018. The current MWPCs (Multi Wire Proportional Chambers) will be replaced by readout chambers consisting of GEM (Gas Electron Multipliers) foils in order to meet the increasing readout rate requirements. QA (Quality Assurance) tests on the GEMs are performed to classify the foils. In this report we present the work done during the CERN Summer Student Programme 2016.

Muon Chamber Endcap Upgrade of the CMS Experiment with Gas Electron Multiplier (GEM) Detectors and their Performance

CERN Document Server

Gola, Mohit

2017-01-01

As the CERN LHC is heading towards a high luminosity phase a very high flux is expected in the endcaps of the CMS Detector. The presence of muons in collision events can be due to rare or new physics so it is important to maintain the high trigger efficiency of the CMS muon system. The CMS Collaboration has proposed to instrument the high-eta region (1.6 lt IetaI lt 2.2) of the muon endcaps with Gas Electron Multiplier (GEM) detectors, referred to as GE1/1 chambers, during the LS2. This technology will help in maintaining optimum trigger performance with maximum selection efficiency of muons even in a high flux environment. We describe plans for a Slice Test to installa few GE1/1 chambers covering 50 degrees in azimuthal angle within the CMS detector in 2017, with subsequent operation during the current Run 2 of the LHC. We show the performance of the GE1/1 chambers to be installed during the slice test, specifically GEM foil leakage currents, chamber gas volume integrity, high voltage circuit performanc...

Analysis of Mechanical Properties for GEM Foil

CERN Document Server

Chin, Yuk Ming

2016-01-01

In view of new assembly technique of the GEM detector; in which three foils stack is stretched to get the uniform gaps among the foils. We studied the mechanical properties of the foil material. We conditioned the samples in different environments to make them extra dry and wet. As holes are the major source of the charge amplification their deformation can effect the detector performance. Therefore in our studies we also studied at which level of the stress the holes deformation is seen. These tensile and holes deformation studies can help to optimize the stress during detector assembly.

Monitoring Cray Cooling Systems

Energy Technology Data Exchange (ETDEWEB)

Maxwell, Don E [ORNL; Ezell, Matthew A [ORNL; Becklehimer, Jeff [Cray, Inc.; Donovan, Matthew J [ORNL; Layton, Christopher C [ORNL

2014-01-01

While sites generally have systems in place to monitor the health of Cray computers themselves, often the cooling systems are ignored until a computer failure requires investigation into the source of the failure. The Liebert XDP units used to cool the Cray XE/XK models as well as the Cray proprietary cooling system used for the Cray XC30 models provide data useful for health monitoring. Unfortunately, this valuable information is often available only to custom solutions not accessible by a center-wide monitoring system or is simply ignored entirely. In this paper, methods and tools used to harvest the monitoring data available are discussed, and the implementation needed to integrate the data into a center-wide monitoring system at the Oak Ridge National Laboratory is provided.

Surface Features and Cathodoluminescence (CL) Characteristics of Corundum Gems from Eastern of Thailand

Science.gov (United States)

Boonsoong, A.

2017-12-01

Thailand has long been well known as a supplier of gemstones and also one of the world's color stone centers for decades. The principal gemstones are corundum, garnet and zircon. The corundum deposits of Chanthaburi-Trat Provinces form the most significant ruby-sapphire concentration in Thailand. Corundums are commonly found in secondary deposits (alluvium, elluvial, residual-soil and colluvium deposits as well as stream sediments) with the thickness of the gem-bearing layer varying from 10-100cm and the thickness of the overburden ranging up to 15m. A number of corundum samples were collected from each of the twenty-nine corundum deposits in the Chanthaburi-Trat gem fields, eastern of Thailand. Corundum varies in colour across the region with colours associated with three geographic zones; a western zone, characterized by blue, green and yellow sapphires; a middle zone with blue, green sapphires plus rubies; and an eastern zone yielding mainly rubies. This project has aim to study surface features and characterize the Cathodoluminescence (CL) of corundum gems in the Chanthaburi-Trat gem fields, Thailand. Surfaces of the corundums under a scanning electron microscope show triangular etch features and randomly oriented needle-like patterns. These reveal that the corundums have interacted with the magma during their ascent to the Earth's surface. Surface features attributable to transport and weathering processes are scratches, conchoidal fractures and a spongy surface appearance. Clay minerals and Fe-Ti oxide minerals deposited on the spongy surfaces of some corundums also indicate that these grains experienced chemical weathering or reacted with the soil solution while they were in the alluvium. Cathodoluminescence shows some blue sapphires to exhibit dull blue luminescence. The main cause of the CL appearance of sapphires is likely to be a quench centre, Fe2+ in their structure. The bright red luminescence in corundum reflects a high Cr3+ content and is always

Aging measurements on triple-GEM detectors operated with $CF_{4}$- based gas mixtures

CERN Document Server

Alfonsi, M; Bencivenni, G; Bonivento, W; Cardini, A; Lener, M P; Murtas, F; Pinci, D; Raspino, D; Saitta, B; De Simone, P

2004-01-01

We present the results of a global irradiation test of full size triple-GEM detectors operated with CF/sub 4/-based gas mixtures. This study has been performed in the framework of an R&D activity on detectors for the innermost region of the first muon station of the LHCb experiment. The prototypes have been irradiated at the Calliope facility of the ENEA-Casaccia with a high intensity 1.25 MeV gamma from a /sup 60/Co source. After the irradiation test the detectors performances have been measured with X-rays and with a 3 GeV pion beam at CERN. A SEM analysis on several samples of the detectors has been performed to complete the understanding of the physical processes occurring in the GEM detector during the strong irradiation.

Optical readout of a triple-GEM detector by means of a CMOS sensor

Energy Technology Data Exchange (ETDEWEB)

Marafini, M. [INFN Sezione di Roma (Italy); Museo Storico della Fisica e Centro Studi e Ricerche “E. Fermi”, Roma (Italy); Patera, V. [INFN Sezione di Roma (Italy); Museo Storico della Fisica e Centro Studi e Ricerche “E. Fermi”, Roma (Italy); Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Pinci, D., E-mail: davide.pinci@roma1.infn.it [INFN Sezione di Roma (Italy); Sarti, A. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma (Italy); Sciubba, A. [INFN Sezione di Roma (Italy); Museo Storico della Fisica e Centro Studi e Ricerche “E. Fermi”, Roma (Italy); Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma (Italy); Spiriti, E. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy)

2016-07-11

In last years, the development of optical sensors has produced objects able to provide very interesting performance. Large granularity is offered along with a very high sensitivity. CMOS sensors with millions of pixels able to detect as few as two or three photons per pixel are commercially available and can be used to read-out the optical signals provided by tracking particle detectors. In this work the results obtained by optically reading-out a triple-GEM detector by a commercial CMOS sensor will be presented. A standard detector was assembled with a transparent window below the third GEM allowing the light to get out. The detector is supplied with an Ar/CF{sub 4} based gas mixture producing 650 nm wavelength photons matching the maximum quantum efficiency of the sensor.

Prediction of Exploration Target Areas for GEM Deposits in Mogok Stone Tract, Northern Myanmar by Integrating Remote Sensing and Geoscience Data

Science.gov (United States)

Oo, Tin Ko

2011-07-01

The Mogok Stone Tract area has long been known for world famous finest ruby since 1597. The Mogok area lies in northern Myanmar and is located at about 205.99km northeast from Mandalay, the second largest city of Myanmar. The Mogok Group of metasedimentary rocks is divided into four units: (1) Wabyudaung Marble, (2) Ayenyeinchantha Calc-silicate, (3) Gwebin Quartzite, and (4) Kabe Gneiss. Igneous rocks in the Mogok area are classified into two units: (1) Kabaing Granite and (2) Pingutaung Leucogranite. The Mogok area has a complex structure involving several folds and faults. Using marbles and calc-silicates as marker horizons, a series of anticline and syncline can be identified such as Mogok syncline, Ongaing anticline, Bawpadan syncline, and Kyatpyin anticline. All the foldings show a low-angle plunge to the south. The main precious stones of the Mogok area are ruby and sapphire; and the other important semi-precious stones are spinel, topaz, peridot, garnet, apatite, beryl, tourmaline (rubellite), quartz, diopside, fluorite, and enstatite. Geological and remote sensing data are processed to extract the indicative features of gem mineralized areas: lithology, structure, and hydrothermal alteration. Density slice version of Landsat ETM band ratios 5/7 is used to map clay alterations. Filtering Landsat ETM band 5 by using edge detection filter is applied for lineament mapping. Spatial integration of various geoscience and remote sensing data sets such as geological maps, Landsat ETM images, and the location map of gem mines show the distribution of alteration zones associated with the gem mineralization in the study area. Geographic Information System (GIS) model has been designed and implemented by ARCVIEW software package based on the overlay of lithologic, lineament, and alteration vector maps. This process has resulted in delineation of most promising areas of probable gem mineralized zones as on the output map.

Summary final report: Contract between the Japan atomic power company and the U.S. Department of Energy Improvement of core safety - study on GEM (III)

International Nuclear Information System (INIS)

Burke, T.M.; Lucoff, D.M.

1997-01-01

This report provides a summary of activities associated with the technical exchange between representatives of the Japan Atomic Power Company (JAPC) and the United States Department of Energy (DOE) regarding the development and testing of Gas Expansion Modules (GEM) at the Fast Flux Test Facility (FFTF). Issuance of this report completes the scope of work defined in the original contract between JAPC and DOE titled ''Study on Improvement of Core Safety - Study on GEM (III).'' Negotiations related to potential modification of the contract are in progress. Under the proposed contract modification, DOE would provide an additional report documenting FFTF pump start tests with GEMs and answer additional JAPC questions related to core safety with and without GEMs

Evaluating penetration-monitoring systems

International Nuclear Information System (INIS)

Markin, J.T.

1981-01-01

Evaluating the performance of a process monitoring system in detecting improper activities that could be related to material diversion requires a framework for addressing the complexity and statistical uncertainty of such systems. This report proposes a methodology that determines the optimal divertor strategy against a monitoring system and the system probability of detection. This method extends previous work by correctly modeling uncorrelated and correlated measurement errors for radiation monitors

Experiential Engineering through iGEM--An Undergraduate Summer Competition in Synthetic Biology

Science.gov (United States)

Mitchell, Rudolph; Dori, Yehudit Judy; Kuldell, Natalie H.

2011-01-01

Unlike students in other engineering disciplines, undergraduates in biological engineering typically have limited opportunity to develop design competencies, and even fewer chances to implement their designed projects. The international Genetically Engineered Machines (iGEM) competition is a student Synthetic Biology competition that, in 2009,…

Environmental radiation monitoring system

International Nuclear Information System (INIS)

Kato, Tsutomu; Shioiri, Masatoshi; Sakamaki, Tsuyoshi

2007-01-01

Environmental radiation monitoring systems are used to measure and monitoring gamma-rays at the observation boundaries of nuclear facilities and in the surrounding areas. In recent years, however, few new nuclear facilities have been constructed and the monitoring systems shift to renewal of existing systems. In addition, in order to increase public acceptance, the facilities are being equipped with communication lines to provide data to prefectural environmental centers. In this text, we introduce the latest technology incorporated in replacement of environmental radiation monitoring systems. We also introduce a replacement method that can shorten the duration during which environmental dose rate measurement is interrupted by enabling both the replacement system and the system being replaced to perform measurements in parallel immediately before and after the replacement. (author)

Ambient water quality in aquifers used for drinking-water supplies, Gem County, southwestern Idaho, 2015

Science.gov (United States)

Bartolino, James R.; Hopkins, Candice B.

2016-12-20

In recent years, the rapid population growth in Gem County, Idaho, has been similar to other counties in southwestern Idaho, increasing about 54 percent from 1990 to 2015. Because the entire population of the study area depends on groundwater for drinking water supply (either from self-supplied domestic, community, or municipal-supply wells), this population growth, along with changes in land use (including potential petroleum exploration and development), indicated to the public and local officials the need to assess the quality of groundwater used for human consumption. To this end, the U.S. Geological Survey, in cooperation with Gem County and the Idaho Department of Environmental Quality, assessed the quality of groundwater from freshwater aquifers used for domestic supply in Gem County. A total of 47 domestic or municipal wells, 1 spring, and 2 surface-water sites on the Payette River were sampled during September 8–November 19, 2015. The sampled water was analyzed for a variety of constituents, including major ions, trace elements, nutrients, bacteria, radionuclides, dissolved gasses, stable isotopes of water and methane, and either volatile organic compounds (VOCs) or pesticides.To better understand analytical results, a conceptual hydrogeologic framework was developed in which three hydrogeologic units were described: Quaternary-Tertiary deposits (QTd), Tertiary Idaho Group rocks (Tig), and Tertiary-Cretaceous igneous rocks (TKi). Water levels were measured in 30 wells during sampling, and a groundwater-level altitude map was constructed for the QTd and Tig units showing groundwater flow toward the Emmett Valley and Payette River.Analytical results indicate that groundwater in Gem County is generally of good quality. Samples collected from two wells contained water with fluoride concentrations greater than the U.S. Environmental Protection Agency (EPA) Maximum Contaminant Level (MCL) of 4 milligrams per liter (mg/L), six wells contained arsenic at

R\\&D results on a CsI-coated triple thick GEM-based photodetector

CERN Document Server

Martinengo, P; Paic, G; Paras, D M; Di Mauro, A; van Hoorne, J; Molnar, L; Peskov, V; Breskin, A

2011-01-01

The very high momentum particle identification detector proposed for the ALICE upgrade is a focusing RICH using a C(4)F(10) gaseous radiator. For the detection of Cherenkov photons, one of the options currently under investigation is to use a CsI-coated triple thick GEM with metallic or resistive electrodes. We will present results from the laboratory studies as well as preliminary results of beam tests of a RICH detector prototype consisting of a CaF(2) radiator coupled to a 10 x 10 cm(2) CsI-coated triple thick GEM equipped with a pad readout and GASSIPLEX-based front-end electronics. With such a prototype the detection of Cherenkov photons simultaneously with minimum ionizing particles has been achieved for the first time in a stable operation mode. (C) 2010 Elsevier B.V. All rights reserved.

Summary final report: Contract between the Japan atomic power company and the U.S. Department of Energy Improvement of core safety - study on GEM (III)

Energy Technology Data Exchange (ETDEWEB)

Burke, T.M.; Lucoff, D.M.

1997-03-18

This report provides a summary of activities associated with the technical exchange between representatives of the Japan Atomic Power Company (JAPC) and the United States Department of Energy (DOE) regarding the development and testing of Gas Expansion Modules (GEM) at the Fast Flux Test Facility (FFTF). Issuance of this report completes the scope of work defined in the original contract between JAPC and DOE titled ''Study on Improvement of Core Safety - Study on GEM (III).'' Negotiations related to potential modification of the contract are in progress. Under the proposed contract modification, DOE would provide an additional report documenting FFTF pump start tests with GEMs and answer additional JAPC questions related to core safety with and without GEMs.

Integrated photovoltaic (PV) monitoring system

Science.gov (United States)

Mahinder Singh, Balbir Singh; Husain, NurSyahidah; Mohamed, Norani Muti

2012-09-01

The main aim of this research work is to design an accurate and reliable monitoring system to be integrated with solar electricity generating system. The performance monitoring system is required to ensure that the PVEGS is operating at an optimum level. The PV monitoring system is able to measure all the important parameters that determine an optimum performance. The measured values are recorded continuously, as the data acquisition system is connected to a computer, and data is stored at fixed intervals. The data can be locally used and can also be transmitted via internet. The data that appears directly on the local monitoring system is displayed via graphical user interface that was created by using Visual basic and Apache software was used for data transmission The accuracy and reliability of the developed monitoring system was tested against the data that captured simultaneously by using a standard power quality analyzer device. The high correlation which is 97% values indicates the level of accuracy of the monitoring system. The aim of leveraging on a system for continuous monitoring system is achieved, both locally, and can be viewed simultaneously at a remote system.

Gasoline, Ethanol and Methanol (GEM) Ternary Blends utilization as an Alternative to Conventional Iraqi Gasoline to Suppress Emitted Sulfur and Lead Components to Environment

OpenAIRE

Miqdam Tariq Chaichan

2016-01-01

Iraqi conventional gasoline characterized by its low octane number not exceed 82 and high lead and sulfur content. In this paper tri-component or ternary, blends of gasoline, ethanol, and methanol presented as an alternative fuel for Iraqi conventional gasoline. The study conducted by using GEM blend that equals E85 blend in octane rating. The used GEM selected from Turner, 2010 collection. G37 E20 M43 (37% gasoline + 20% ethanol+ 43% methanol) was chosen as GEM in present study. This blend u...

Operation of gas electron multiplier (GEM) with propane gas at low pressure and comparison with tissue-equivalent gas mixtures

Energy Technology Data Exchange (ETDEWEB)

De Nardo, L., E-mail: laura.denardo@unipd.it [University of Padova, Physics and Astronomy Department and PD-INFN, via Marzolo 8, I-35131 Padova (Italy); Farahmand, M., E-mail: majid.farahmand@rivm.nl [Centre for Environmental Safety and Security, National Institute for Public Health and the Environment (RIVM), PO Box 1, NL-3720 BA Bilthoven (Netherlands)

2016-05-21

A Tissue-Equivalent Proportional Counter (TEPC), based on a single GEM foil of standard geometry, has been tested with pure propane gas at low pressure, in order to simulate a tissue site of about 1 µm equivalent size. In this work, the performance of GEM with propane gas at a pressure of 21 and 28 kPa will be presented. The effective gas gain was measured in various conditions using a {sup 244}Cm alpha source. The dependence of effective gain on the electric field strength along the GEM channel and in the drift and induction region was investigated. A maximum effective gain of about 5×10{sup 3} has been reached. Results obtained in pure propane gas are compared with gas gain measurements in gas mixtures commonly employed in microdosimetry, that is propane and methane based Tissue-Equivalent gas mixtures.

Tunable Cascade Reaction of Aryl Diazonium Salts and Trialkylamine: Synthesis of Monofluorinated Arylhydrazones and gem-Difluorinated Azo Compounds.

Science.gov (United States)

Guo, Rui; Zhang, Zhengjuan; Shi, Feng; Tang, Pingping

2016-03-04

The first example of a mild and tunable cascade reaction of aryl diazonium salts and trialkylamine in the presence of Selectfluor to prepare monofluorinated arylhydrazones and gem-difluorinated azo compounds without metal has been explored. In the presence of H2O, the monofluorinated arylhydrazones were observed in moderate to good yield. In the absence of H2O, the gem-difluorinated azo compounds were obtained. The fluorinated arylhydrazones were utilized to synthesize fluorinated pyrazoles and other nitrogen-containing compounds.

Evaluation of the influence of the TH-GEM detector components in dosimetric measurements of standard mammography beams

Energy Technology Data Exchange (ETDEWEB)

Silva, Natália F.; Castro, Maysa C.; Caldas, Linda V.E., E-mail: nsilva@ipen.br, E-mail: maysadecastro@gmail.com, E-mail: fbelonsi@gmail.com, E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Silva, Tiago F.; Cintra, Felipe B.; Luz, Hugo N. da, E-mail: tfsilva@if.usp.br, E-mail: hugonluz@if.usp.br [Universidade de São Paulo (IF/USP), São Paulo, SP (Brazil). Instituto de Física

2017-07-01

GEM detectors have found applications in many areas due to their simplicity of construction, low cost, ruggedness and diversity of shape. A dosimeter with these qualities presents utility in several applications, as for example in diagnostic and therapeutic medicine, industrial radiography and nuclear meters. Furthermore, the high sensitivity provided by GEM detectors may extend their applications in low dose dosimetry. Based on these facts, it may be interesting to produce a prototype of a portable TH-GEM type detector with characteristics suitable for dosimetric use in X-rays with low and medium energies. The precise determination of the dosimeter characteristics is very important for laboratories of instrument calibration, as well as to determine how the various components of the detector may influence on the energy deposited in the sensitive volume. In this work, the results obtained about the influence of each one of the components present in this type of detector in standard mammography beams is presented. The code MCNP5 was used. The results allowed the adaptation of the detector to the desired conditions. (author)

A GEM-TPC in twin configuration for the Super-FRS tracking of heavy ions at FAIR

Science.gov (United States)

García, F.; Grahn, T.; Hoffmann, J.; Jokinen, A.; Kaya, C.; Kunkel, J.; Rinta-Antila, S.; Risch, H.; Rusanov, I.; Schmidt, C. J.; Simon, H.; Simons, C.; Turpeinen, R.; Voss, B.; Äystö, J.; Winkler, M.

2018-03-01

The GEM-TPC described herein will be part of the standard beam-diagnostics equipment of the Super-FRS. This chamber will provide tracking information for particle identification at rates up to 1 MHz on an event-by-event basis. The key requirements of operation for these chambers are: close to 100% tracking efficiency under conditions of high counting rate, spatial resolution below 1 mm and a superb large dynamic range covering projectiles from Z = 1 up to Z = 92. The current prototype consists of two GEM-TPCs inside a single vessel, which are operating independently and have electrical drift fields in opposite directions. The twin configuration is done by flipping one of the GEM-TPCs on the middle plane with respect to the second one. In order to put this development in context, the evolution of previous prototypes will be described and its performances discussed. Finally, this chamber was tested at the University of Jyväskylä accelerator with proton projectiles and at GSI with Uranium, Xenon, fragments and Carbon beams. The results obtained have shown a position resolution between 120 to 300 μm at moderate counting rate under conditions of full tracking efficiency.

Inductive Monitoring System (IMS)

Data.gov (United States)

National Aeronautics and Space Administration — IMS: Inductive Monitoring System The Inductive Monitoring System (IMS) is a tool that uses a data mining technique called clustering to extract models of normal...

CERN safety system monitoring - SSM

International Nuclear Information System (INIS)

Hakulinen, T.; Ninin, P.; Valentini, F.; Gonzalez, J.; Salatko-Petryszcze, C.

2012-01-01

CERN SSM (Safety System Monitoring) is a system for monitoring state-of-health of the various access and safety systems of the CERN site and accelerator infrastructure. The emphasis of SSM is on the needs of maintenance and system operation with the aim of providing an independent and reliable verification path of the basic operational parameters of each system. Included are all network-connected devices, such as PLCs (local purpose control unit), servers, panel displays, operator posts, etc. The basic monitoring engine of SSM is a freely available system-monitoring framework Zabbix, on top of which a simplified traffic-light-type web-interface has been built. The web-interface of SSM is designed to be ultra-light to facilitate access from hand-held devices over slow connections. The underlying Zabbix system offers history and notification mechanisms typical of advanced monitoring systems. (authors)

Development of Large-Area GEM Detectors for the Forward Muon Endcap Upgrade of the CMS Experiment and Search for SM Higgs Boson Decay in the $H\\to\\tau^{+}\\tau^{-}\\to\\mu^{+}\\mu^{-}\\bar{\

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00366476; Gallo, Elisabetta; Raspereza, Alexei

Gas Electron Multiplier (GEM) technology is being considered for the forward muon upgrade of the Compact Muon Solenoid (CMS) experiment in \\mbox{Phase II} of the CERN LHC. The first GEM Endcap (GE1/1) is going to be installed in the $1.5 < \\mid\\eta\\mid < 2.2$ region of the muon endcapˆ’ mainly to control muon level-1 trigger rates after the second long LHC shutdown. A GE1/1 triple-GEM detector is read out by 3,072 radial strips with 453 $\\mu$rad pitch arranged in eight $\\eta$-sectors. A meter-long GE1/1 prototype-III was assembled at Florida Tech and tested in 20-120 GeV hadron beams at Fermilab using Ar/CO$_{2}$ 70:30 and the RD51 Scalable Readout System (SRS). Four GEM detectors with 2-D readout and an average measured azimuthal resolution of 36$\\mu$rad provided precise reference tracks. Construction of this GE1/1 prototype-III detector and its performance in the test beam are described. Strip cluster parameters, detection efficiency, and spatial resolution are studied with position and high voltag...

Testing of self-triggered nXYTER electronics for integrating with GEM detector for high frequency operation

International Nuclear Information System (INIS)

Saini, J.; Dubey, A.K.; Chattopadhyay, S.; Singaraju, R.N.

2013-01-01

A GEM-based tracking system is planned to be used for muon tracking in the proposed CBM experiment at FAIR. The peak hit density in the central region of the chamber is expected to reach 1 MHz/cm 2 . For a detector to be operational at high intensity (upto MHz), it is useful to know the compatibility of the readout electronics with the detector. At very high rates and sufficiently large signal amplitude, there is a possibility of preamplifier saturation resulting in zero or distorted amplitude of the output signal

Comparison of Experiment and Simulation of the triple GEM-Based Fast Neutron Detector

International Nuclear Information System (INIS)

Wang Xiao-Dong; Luo Wen; Zhang Jun-Wei; Yang He-Run; Duan Li-Min; Lu Chen-Gui; Hu Rong-Jiang; Hu Bi-Tao; Zhang Chun-Hui; Yang Lei; Zhou Jian-Rong; An Lv-Xing

2015-01-01

A detector for fast neutrons based on a 10 × 10 cm"2 triple gas electron multiplier (GEM) device is developed and tested. A neutron converter, which is a high density polyethylene (HDPE) layer, is combined with the triple GEM detector cathode and placed inside the detector, in the path of the incident neutrons. The detector is tested by obtaining the energy deposition spectrum with an Am Be neutron source in the Institute of Modern Physics (IMP) at Lanzhou. In the present work we report the results of the tests and compare them with those of simulations. The transport of fast neutrons and their interactions with the different materials in the detector are simulated with the GEANT4 code, to understand the experimental results. The detector displays a clear response to the incident fast neutrons. However, an unexpected disagreement in the energy dependence of the response between the simulated and measured spectra is observed. The neutron sources used in our simulation include deuterium-tritium (DT, 14 MeV), deuterium-deuterium (DD, 2.45 MeV), and Am Be sources. The simulation results also show that among the secondary particles generated by the incident neutron, the main contributions to the total energy deposition are from recoil protons induced in hydrogen-rich HDPE or Kapton (GEM material), and activation photons induced by neutron interaction with Ar atoms. Their contributions account for 90% of the total energy deposition. In addition, the dependence of neutron deposited energy spectrum on the composition of the gas mixture is presented. (paper)

Preliminary Theoretical Interpretation of the Tajmar Frame Dragging Effect Through the GEM Theory

International Nuclear Information System (INIS)

Brandenburg, John

2009-01-01

A preliminary theoretical explanation for the large amplitude frame dragging effect seen by Tajmar et al.(2007) is proposed. A simple theory of quantum photon fields mediating electrodynamics is derived based on concepts from QED. These are then expressed as quantum wave functions for rotating EM systems. Based on the GEM theory, it is proposed that gravitational frame dragging relies on similar photon wave functions. The constructive interference of the frame dragging fields with co-rotating EM photon fields coupled to Bose-Einstein components in matter at low temperatures results in a large frame dragging term due to a mixed gravity-EM term that is larger by a factor of approximately 10 20 than ordinary frame dragging.

A time projection chamber with GEM-based readout

Energy Technology Data Exchange (ETDEWEB)

Attié, David [CEA Saclay, IRFU, F-91191 Gif-sur-Yvette (France); Behnke, Ties [Deutsches Elektronen-Synchrotron DESY, A Research Centre of the Helmholtz Association, Notkestrasse 85, 22607 Hamburg (Hamburg site) (Germany); Bellerive, Alain [Carleton University, Department of Physics, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6 (Canada); Bezshyyko, Oleg [Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, City of Kyiv 01601 (Ukraine); Bhattacharya, Deb Sankar [CEA Saclay, IRFU, F-91191 Gif-sur-Yvette (France); now at Saha Institute of Nuclear Physics, 1/AF, Sector 1, Bidhan Nagar, Kolkata 700064 (India); Bhattacharya, Purba [Saha Institute of Nuclear Physics, 1/AF, Sector 1, Bidhan Nagar, Kolkata 700064 (India); now at National Institute of Science Education and Research (NISER) Bhubaneswar, P.O. Jatni, Khurda 752050, Odisha (India); Bhattacharya, Sudeb [Saha Institute of Nuclear Physics, 1/AF, Sector 1, Bidhan Nagar, Kolkata 700064 (India); Caiazza, Stefano [Deutsches Elektronen-Synchrotron DESY, A Research Centre of the Helmholtz Association, Notkestrasse 85, 22607 Hamburg (Hamburg site) (Germany); now at Johannes Gutenberg Universität Mainz, Institut für Physik, 55099 Mainz (Germany); Colas, Paul [CEA Saclay, IRFU, F-91191 Gif-sur-Yvette (France); Lentdecker, Gilles De [Inter University ULB-VUB, Av. Fr. Roosevelt 50, B1050 Bruxelles (Belgium); Dehmelt, Klaus [Deutsches Elektronen-Synchrotron DESY, A Research Centre of the Helmholtz Association, Notkestrasse 85, 22607 Hamburg (Hamburg site) (Germany); now at State University of New York at Stony Brook, Department of Physics and Astronomy, Stony Brook, NY 11794-3800 (United States); Desch, Klaus [Universität Bonn, Physikalisches Institut, Nußallee 12, 53115 Bonn (Germany); and others

2017-06-01

For the International Large Detector concept at the planned International Linear Collider, the use of time projection chambers (TPC) with micro-pattern gas detector readout as the main tracking detector is investigated. In this paper, results from a prototype TPC, placed in a 1 T solenoidal field and read out with three independent Gas Electron Multiplier (GEM) based readout modules, are reported. The TPC was exposed to a 6 GeV electron beam at the DESY II synchrotron. The efficiency for reconstructing hits, the measurement of the drift velocity, the space point resolution and the control of field inhomogeneities are presented.

Copilot: Monitoring Embedded Systems

Science.gov (United States)

Pike, Lee; Wegmann, Nis; Niller, Sebastian; Goodloe, Alwyn

2012-01-01

Runtime verification (RV) is a natural fit for ultra-critical systems, where correctness is imperative. In ultra-critical systems, even if the software is fault-free, because of the inherent unreliability of commodity hardware and the adversity of operational environments, processing units (and their hosted software) are replicated, and fault-tolerant algorithms are used to compare the outputs. We investigate both software monitoring in distributed fault-tolerant systems, as well as implementing fault-tolerance mechanisms using RV techniques. We describe the Copilot language and compiler, specifically designed for generating monitors for distributed, hard real-time systems. We also describe two case-studies in which we generated Copilot monitors in avionics systems.

Waste monitoring system for effluents

International Nuclear Information System (INIS)

Macdonald, J.M.; Gomez, B.; Trujillo, L.; Malcom, J.E.; Nekimken, H.; Pope, N.; Bibeau, R.

1995-07-01

The waste monitoring system in use at Los Alamos National Laboratory's Plutonium Facility, TA-55, is a computer-based system that proves real-time information on industrial effluents. Remote computers monitor discharge events and data moves from one system to another via a local area network. This report describes the history, system design, summary, instrumentation list, displays, trending screens, and layout of the waste monitoring system

Performance verification of the Gravity and Extreme Magnetism Small explorer (GEMS) x-ray polarimeter

Science.gov (United States)

Enoto, Teruaki; Black, J. Kevin; Kitaguchi, Takao; Hayato, Asami; Hill, Joanne E.; Jahoda, Keith; Tamagawa, Toru; Kaneko, Kenta; Takeuchi, Yoko; Yoshikawa, Akifumi; Marlowe, Hannah; Griffiths, Scott; Kaaret, Philip E.; Kenward, David; Khalid, Syed

2014-07-01

Polarimetry is a powerful tool for astrophysical observations that has yet to be exploited in the X-ray band. For satellite-borne and sounding rocket experiments, we have developed a photoelectric gas polarimeter to measure X-ray polarization in the 2-10 keV range utilizing a time projection chamber (TPC) and advanced micro-pattern gas electron multiplier (GEM) techniques. We carried out performance verification of a flight equivalent unit (1/4 model) which was planned to be launched on the NASA Gravity and Extreme Magnetism Small Explorer (GEMS) satellite. The test was performed at Brookhaven National Laboratory, National Synchrotron Light Source (NSLS) facility in April 2013. The polarimeter was irradiated with linearly-polarized monochromatic X-rays between 2.3 and 10.0 keV and scanned with a collimated beam at 5 different detector positions. After a systematic investigation of the detector response, a modulation factor >=35% above 4 keV was obtained with the expected polarization angle. At energies below 4 keV where the photoelectron track becomes short, diffusion in the region between the GEM and readout strips leaves an asymmetric photoelectron image. A correction method retrieves an expected modulation angle, and the expected modulation factor, ~20% at 2.7 keV. Folding the measured values of modulation through an instrument model gives sensitivity, parameterized by minimum detectable polarization (MDP), nearly identical to that assumed at the preliminary design review (PDR).

Performance Verification of the Gravity and Extreme Magnetism Small Explorer GEMS X-Ray Polarimeter

Science.gov (United States)

Enoto, Teruaki; Black, J. Kevin; Kitaguchi, Takao; Hayato, Asami; Hill, Joanne E.; Jahoda, Keith; Tamagawa, Toru; Kanako, Kenta; Takeuchi, Yoko; Yoshikawa, Akifumi;

The 2.3 GHz continuum survey of the GEM project

Science.gov (United States)

Tello, C.; Villela, T.; Torres, S.; Bersanelli, M.; Smoot, G. F.; Ferreira, I. S.; Cingoz, A.; Lamb, J.; Barbosa, D.; Perez-Becker, D.; Ricciardi, S.; Currivan, J. A.; Platania, P.; Maino, D.

2013-08-01

Context. Determining the spectral and spatial characteristics of the radio continuum of our Galaxy is an experimentally challenging endeavour for improving our understanding of the astrophysics of the interstellar medium. This knowledge has also become of paramount significance for cosmology, since Galactic emission is the main source of astrophysical contamination in measurements of the cosmic microwave background (CMB) radiation on large angular scales. Aims: We present a partial-sky survey of the radio continuum at 2.3GHz within the scope of the Galactic Emission Mapping (GEM) project, an observational program conceived and developed to reveal the large-scale properties of Galactic synchrotron radiation through a set of self-consistent surveys of the radio continuum between 408MHz and 10GHz. Methods: The GEM experiment uses a portable and double-shielded 5.5-m radiotelescope in altazimuthal configuration to map 60-degree-wide declination bands from different observational sites by circularly scanning the sky at zenithal angles of 30° from a constantly rotating platform. The observations were accomplished with a total power receiver, whose front-end high electron mobility transistor (HEMT) amplifier was matched directly to a cylindrical horn at the prime focus of the parabolic reflector. The Moon was used to calibrate the antenna temperature scale and the preparation of the map required direct subtraction and destriping algorithms to remove ground contamination as the most significant source of systematic error. Results: We used 484 h of total intensity observations from two locations in Colombia and Brazil to yield 66% sky coverage from to . The observations in Colombia were obtained with a horizontal HPBW of and a vertical HPBW of . The pointing accuracy was and the RMS sensitivity was 11.42 mK. The observations in Brazil were obtained with a horizontal HPBW of and a vertical HPBW of . The pointing accuracy was and the RMS sensitivity was 8.24 mK. The zero

VME system monitor board

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-02-01

Much of the machinery throughout the APS will be controlled by VME based computers. In order to increase the reliability of the system, it is necessary to be able to monitor the status of each VME crate. In order to do this, a VME System Monitor was created. In addition to being able to monitor and report the status (watchdog timer, temperature, CPU (Motorola MVME 167) state (status, run, fail), and the power supply), it includes provisions to remotely reset the CPU and VME crate, digital I/O, and parts of the transition module (serial port and ethernet connector) so that the Motorla MVME 712 is not needed. The standard VME interface was modified on the System Monitor so that in conjunction with the Motorola MVME 167 a message based VXI interrupt handler could is implemented. The System Monitor is a single VME card (6U). It utilizes both the front panel and the P2 connector for I/O. The front panel contains a temperature monitor, watchdog status LED, 4 general status LEDs, input for a TTL interrupt, 8 binary inputs (24 volt, 5 volt, and dry contact sense), 4 binary outputs (dry contact, TTL, and 100 mA), serial port (electrical RS-232 or fiber optic), ethernet transceiver (10 BASE-FO or AUI), and a status link to neighbor crates. The P2 connector is used to provide the serial port and ethernet to the processor. In order to abort and read the status of the CPU, a jumper cable must be connected between the CPU and the System Monitor.

Stages of Psychometric Measure Development: The Example of the Generalized Expertise Measure (GEM)

Science.gov (United States)

Germain, Marie-Line

2006-01-01

This paper chronicles the steps, methods, and presents hypothetical results of quantitative and qualitative studies being conducted to develop a Generalized Expertise Measure (GEM). Per Hinkin (1995), the stages of scale development are domain and item generation, content expert validation, and pilot test. Content/face validity and internal…

Environmental monitoring and information systems

International Nuclear Information System (INIS)

Gibbert, R.

1998-01-01

Environmental monitoring and information systems installed by Dornier are summarized. A broad spectrum of environmental areas from air quality and water to radioactivity is covered. Nuclear power plant monitoring systems, either as remote or plant-internal monitoring systems, form an important element of the work undertaken. The systems delivered covered local, regional or national areas. The range of services provided, and hardware and software platforms are listed. (R.P.)

Data monitoring system of technical diagnosis system for EAST

International Nuclear Information System (INIS)

Qian Jing; Weng Peide; Chen Zhuomin; Wu Yu; Xi Weibin; Luo Jiarong

2010-01-01

Technical diagnosis system (TDS) is an important subsystem to monitor status parameters of EAST (experimental advanced superconducting tokamak). The upgraded TDS data monitoring system is comprised of management floor, monitoring floor and field floor.. Security protection, malfunction record and analysis are designed to make the system stable, robust and friendly. During the past EAST campaigns, the data monitoring system has been operated reliably and stably. The signal conditioning system and software architecture are described. (authors)

The JOYO remote monitoring system

International Nuclear Information System (INIS)

Damico, Joseph P.; Hashimoto, Yu

2000-01-01

The evolution of the personal computer, operating systems and applications software and the Internet has brought drastic change and many benefits worldwide. Remote monitoring systems benefit from computer network and other modern software technologies. The availability of fast, inexpensive and secure communications enables new solutions for monitoring system applications. The JOYO Remote Monitoring System (RMS) utilizes computer network communications and modular software design to provide a distributed integrated solution for monitoring multiple storage locations. This paper describes the remote monitoring system installed at the JOYO Fast Reactor. The system combines sensors, software, and computer network technologies to create a powerful data collection, storage and dissemination capability. The RMS provides a flexible, scalable solution for a variety of applications. The RMS integrates a variety of state of the art technologies from several sources and serves as a test bed for cutting edge technologies that can be shared with outside users. This paper describes the system components and their operation and discusses system benefits. Current activities and future plants for the JOYO RMS will be discussed. (author)

Unattended Monitoring System Design Methodology

International Nuclear Information System (INIS)

Drayer, D.D.; DeLand, S.M.; Harmon, C.D.; Matter, J.C.; Martinez, R.L.; Smith, J.D.

1999-01-01

A methodology for designing Unattended Monitoring Systems starting at a systems level has been developed at Sandia National Laboratories. This proven methodology provides a template that describes the process for selecting and applying appropriate technologies to meet unattended system requirements, as well as providing a framework for development of both training courses and workshops associated with unattended monitoring. The design and implementation of unattended monitoring systems is generally intended to respond to some form of policy based requirements resulting from international agreements or domestic regulations. Once the monitoring requirements are established, a review of the associated process and its related facilities enables identification of strategic monitoring locations and development of a conceptual system design. The detailed design effort results in the definition of detection components as well as the supporting communications network and data management scheme. The data analyses then enables a coherent display of the knowledge generated during the monitoring effort. The resultant knowledge is then compared to the original system objectives to ensure that the design adequately addresses the fundamental principles stated in the policy agreements. Implementation of this design methodology will ensure that comprehensive unattended monitoring system designs provide appropriate answers to those critical questions imposed by specific agreements or regulations. This paper describes the main features of the methodology and discusses how it can be applied in real world situations

Preliminary Evaluation of Method to Monitor Landfills Resilience against Methane Emission

Science.gov (United States)

Chusna, Noor Amalia; Maryono, Maryono

2018-02-01

Methane emission from landfill sites contribute to global warming and un-proper methane treatment can pose an explosion hazard. Stakeholder and government in the cities in Indonesia been found significant difficulties to monitor the resilience of landfill from methane emission. Moreover, the management of methane gas has always been a challenging issue for long waste management service and operations. Landfills are a significant contributor to anthropogenic methane emissions. This study conducted preliminary evaluation of method to manage methane gas emission by assessing LandGem and IPCC method. From the preliminary evaluation, this study found that the IPCC method is based on the availability of current and historical country specific data regarding the waste disposed of in landfills while from the LandGEM method is an automated tool for estimating emission rates for total landfill gas this method account total gas of methane, carbon dioxide and other. The method can be used either with specific data to estimate emissions in the site or default parameters if no site-specific data are available. Both of method could be utilize to monitor the methane emission from landfill site in cities of Central Java.

Savannah River Plant remote environmental monitoring system

International Nuclear Information System (INIS)

Schubert, J.F.

1987-01-01

The SRP remote environmental monitoring system consists of separations facilities stack monitors, production reactor stack monitors, twelve site perimeter monitors, river and stream monitors, a geostationary operational environmental satellite (GOES) data link, reactor cooling lake thermal monitors, meteorological tower system, Weather Information and Display (WIND) system computer, and the VANTAGE data base management system. The remote environmental monitoring system when fully implemented will provide automatic monitoring of key stack releases and automatic inclusion of these source terms in the emergency response codes

Arduino Based Infant Monitoring System

Science.gov (United States)

Farhanah Mohamad Ishak, Daing Noor; Jamil, Muhammad Mahadi Abdul; Ambar, Radzi

2017-08-01

This paper proposes a system for monitoring infant in an incubator and records the relevant data into a computer. The data recorded by the system can be further referred by the neonatal intensive care unit (NICU) personnel for diagnostic or research purposes. The study focuses on designing the monitoring system that consists of an incubator equipped with humidity sensor to measure the humidity level, and a pulse sensor that can be attached on an infant placed inside the incubator to monitor infant’s heart pulse. The measurement results which are the pulse rate and humidity level are sent to the PC via Arduino microcontroller. The advantage of this system will be that in the future, it may also enable doctors to closely monitor the infant condition through local area network and internet. This work is aimed as an example of an application that contributes towards remote tele-health monitoring system.

X-ray Polarization from Black Holes: GEMS Scientific White Paper

OpenAIRE

Schnittman, Jeremy; Angelini, Lorella; Baring, Matthew; Baumgartner, Wayne; Black, Kevin; Dotson, Jessie; Ghosh, Pranab; Harding, Alice; Hill, Joanne; Jahoda, Keith; Kaaret, Phillip; Kallman, Tim; Krawczynski, Henric; Krolik, Julian; Lai, Dong

2013-01-01

We present here a summary of the scientific goals behind the Gravity and Extreme Magnetism SMEX (GEMS) X-ray polarimetry mission's black hole (BH) observing program. The primary targets can be divided into two classes: stellar-mass galactic BHs in accreting binaries, and super-massive BHs in the centers of active galactic nuclei (AGN). The stellar-mass BHs can in turn be divided into various X-ray spectral states: thermal-dominant (disk), hard (radio jet), and steep power-law (hot corona). Th...

The R + D transfer in Spain: diagnostic based 2006 GEM

International Nuclear Information System (INIS)

Coduras Martinez, A.; Urbano Pulido, D.; Ruiz Navarro, J.

2007-01-01

The main purpose of this research is to analyse in the international context the situation today of the Spanish R and D transference from the scientific field to the firms, using 2006 GEM data as well as complementary data sources. The main findings of the study emphasize a difficult scenario concerning the R and D transference to the Spanish enterprises. Although these negative results, some data suggest a significant improvement in this area in the near future. (Author) 9 refs

Depletion of pro-oncogenic RUNX2 enhances gemcitabine (GEM) sensitivity of p53-mutated pancreatic cancer Panc-1 cells through the induction of pro-apoptotic TAp63.

Science.gov (United States)

Ozaki, Toshinori; Nakamura, Mizuyo; Ogata, Takehiro; Sang, Meijie; Yoda, Hiroyuki; Hiraoka, Kiriko; Sang, Meixiang; Shimozato, Osamu

2016-11-01

Recently, we have described that siRNA-mediated silencing of runt-related transcription factor 2 (RUNX2) improves anti-cancer drug gemcitabine (GEM) sensitivity of p53-deficient human pancreatic cancer AsPC-1 cells through the augmentation of p53 family TAp63-dependent cell death pathway. In this manuscript, we have extended our study to p53-mutated human pancreatic cancer Panc-1 cells. According to our present results, knockdown of mutant p53 alone had a marginal effect on GEM-mediated cell death of Panc-1 cells. We then sought to deplete RUNX2 using siRNA in Panc-1 cells and examined its effect on GEM sensitivity. Under our experimental conditions, RUNX2 knockdown caused a significant enhancement of GEM sensitivity of Panc-1 cells. Notably, GEM-mediated induction of TAp63 but not of TAp73 was further stimulated in RUNX2-depleted Panc-1 cells, indicating that, like AsPC-1 cells, TAp63 might play a pivotal role in the regulation of GEM sensitivity of Panc-1 cells. Consistent with this notion, forced expression of TAp63α in Panc-1 cells promoted cell cycle arrest and/or cell death, and massively increased luciferase activities driven by TAp63-target gene promoters such as p21WAF1 and NOXA. In addition, immunoprecipitation experiments indicated that RUNX2 forms a complex with TAp63 in Panc-1 cells. Taken together, our current observations strongly suggest that depletion of RUNX2 enhances the cytotoxic effect of GEM on p53-mutated Panc-1 cells through the stimulation of TAp63-dependent cell death pathway even in the presence of a large amount of pro-oncogenic mutant p53, and might provide an attractive strategy to treat pancreatic cancer patients with p53 mutations.

ENED-GEM: A Conceptual Framework Model for Psychological Enjoyment Factors and Learning Mechanisms in Educational Games about the Environment

Science.gov (United States)

Fjællingsdal, Kristoffer S.; Klöckner, Christian A.

2017-01-01

Based on a thorough review of psychological literature, this article seeks to develop a model of game enjoyment and environmental learning (ENvironmental EDucational Game Enjoyment Model, ENED-GEM) and delineate psychological processes that might facilitate learning and inspire behavioral change from educational games about the environment. A critically acclaimed digital educational game about environmental issues (Fate of the World by Red Redemption/Soothsayer Games) was used as a case study. Two hundred forty-nine reviews of the game from the popular gaming and reviewing platform known as Steam were analyzed by means of a thematic content analysis in order to identify key player enjoyment factors believed to be relevant to the process of learning from games, as well as to gain an understanding of positive and negative impressions about the game’s general content. The end results of the thematic analysis were measured up to the suggested ENED-GEM framework. Initial results generally support the main elements of the ENED-GEM, and future research into the importance of these individual core factors is outlined. PMID:28701988

ENED-GEM: A Conceptual Framework Model for Psychological Enjoyment Factors and Learning Mechanisms in Educational Games about the Environment

Directory of Open Access Journals (Sweden)

Kristoffer S. Fjællingsdal

2017-06-01

Full Text Available Based on a thorough review of psychological literature, this article seeks to develop a model of game enjoyment and environmental learning (ENvironmental EDucational Game Enjoyment Model, ENED-GEM and delineate psychological processes that might facilitate learning and inspire behavioral change from educational games about the environment. A critically acclaimed digital educational game about environmental issues (Fate of the World by Red Redemption/Soothsayer Games was used as a case study. Two hundred forty-nine reviews of the game from the popular gaming and reviewing platform known as Steam were analyzed by means of a thematic content analysis in order to identify key player enjoyment factors believed to be relevant to the process of learning from games, as well as to gain an understanding of positive and negative impressions about the game’s general content. The end results of the thematic analysis were measured up to the suggested ENED-GEM framework. Initial results generally support the main elements of the ENED-GEM, and future research into the importance of these individual core factors is outlined.

ENED-GEM: A Conceptual Framework Model for Psychological Enjoyment Factors and Learning Mechanisms in Educational Games about the Environment.

Science.gov (United States)

Fjællingsdal, Kristoffer S; Klöckner, Christian A

2017-01-01

Based on a thorough review of psychological literature, this article seeks to develop a model of game enjoyment and environmental learning (ENvironmental EDucational Game Enjoyment Model, ENED-GEM) and delineate psychological processes that might facilitate learning and inspire behavioral change from educational games about the environment. A critically acclaimed digital educational game about environmental issues (Fate of the World by Red Redemption/Soothsayer Games) was used as a case study. Two hundred forty-nine reviews of the game from the popular gaming and reviewing platform known as Steam were analyzed by means of a thematic content analysis in order to identify key player enjoyment factors believed to be relevant to the process of learning from games, as well as to gain an understanding of positive and negative impressions about the game's general content. The end results of the thematic analysis were measured up to the suggested ENED-GEM framework. Initial results generally support the main elements of the ENED-GEM, and future research into the importance of these individual core factors is outlined.

The GED4GEM project: development of a Global Exposure Database for the Global Earthquake Model initiative

Science.gov (United States)

Gamba, P.; Cavalca, D.; Jaiswal, K.S.; Huyck, C.; Crowley, H.

2012-01-01

In order to quantify earthquake risk of any selected region or a country of the world within the Global Earthquake Model (GEM) framework (www.globalquakemodel.org/), a systematic compilation of building inventory and population exposure is indispensable. Through the consortium of leading institutions and by engaging the domain-experts from multiple countries, the GED4GEM project has been working towards the development of a first comprehensive publicly available Global Exposure Database (GED). This geospatial exposure database will eventually facilitate global earthquake risk and loss estimation through GEM’s OpenQuake platform. This paper provides an overview of the GED concepts, aims, datasets, and inference methodology, as well as the current implementation scheme, status and way forward.

System health monitoring

International Nuclear Information System (INIS)

Reneke, J.A.; Fryer, M.O.

1995-01-01

Well designed large systems include many instrument taking data. These data are used in a variety of ways. They are used to control the system and its components, to monitor system and component health, and often for historical or financial purposes. This paper discusses a new method of using data from low level instrumentation to monitor system and component health. The method uses the covariance of instrument outputs to calculate a measure of system change. The method involves no complicated modeling since it is not a parameter estimation algorithm. The method is iterative and can be implemented on a computer in real time. Examples are presented for a metal lathe and a high efficiency particulate air (HEPA) filter. It is shown that the proposed method is quite sensitive to system changes such as wear out and failure. The method is useful for low level system diagnostics and fault detection

Operational experience with the GEM detector assembly lines for the CMS forward muon upgrade

CERN Document Server

Vai, Ilaria

2017-01-01

The CMS Collaboration has been developing large-area Triple-GEM detectors to be installed in the muon endcap regions of the CMS experiment in 2019 to maintain forward muon trigger and tracking performance at the HL-LHC. Ten pre-production detectors were built at CERN to commission the first assembly line and the quality controls. These were installed in the CMS detector in early 2017 and are currently participating in the 2017 LHC run. The collaboration has prepared several additional assembly and quality control lines for distributed mass production of 160 GEM detectors at various sites worldwide. During 2017, these additional production sites have been optimizing construction techniques and quality control procedures and validating them against common specifications by constructing additional pre-production detectors. Using the specific experience from one production site as an example, we discuss how the quality controls make use of independent hardware and trained personnel to ensure fast and reliable pro...

Integrated Monitoring System of Production Processes

Directory of Open Access Journals (Sweden)

Oborski Przemysław

2016-12-01

Full Text Available Integrated monitoring system for discrete manufacturing processes is presented in the paper. The multilayer hardware and software reference model was developed. Original research are an answer for industry needs of the integration of information flow in production process. Reference model corresponds with proposed data model based on multilayer data tree allowing to describe orders, products, processes and save monitoring data. Elaborated models were implemented in the integrated monitoring system demonstrator developed in the project. It was built on the base of multiagent technology to assure high flexibility and openness on applying intelligent algorithms for data processing. Currently on the base of achieved experience an application integrated monitoring system for real production system is developed. In the article the main problems of monitoring integration are presented, including specificity of discrete production, data processing and future application of Cyber-Physical-Systems. Development of manufacturing systems is based more and more on taking an advantage of applying intelligent solutions into machine and production process control and monitoring. Connection of technical systems, machine tools and manufacturing processes monitoring with advanced information processing seems to be one of the most important areas of near future development. It will play important role in efficient operation and competitiveness of the whole production system. It is also important area of applying in the future Cyber-Physical-Systems that can radically improve functionally of monitoring systems and reduce the cost of its implementation.

Maintenance of radiation monitoring systems

International Nuclear Information System (INIS)

Aoyama, Kei

2001-01-01

As the safety and quality of atomic power facilities are more strongly required, the reliability improvement and preventive maintenance of radiation monitoring systems are important. This paper describes the maintenance of radiation monitoring systems delivered by Fuji Electric and the present status of preventive maintenance technology. Also it introduces the case that we developed a fault diagnosis function adopting a statistics technique and artificial intelligence (AI) and delivered a radiation monitoring system including this function. This system can output a fault analysis result and a countermeasure from the computer in real time. (author)

Configuration of Risk Monitor System by PLant Defense-In.Depth Monitor and Relability Monitor

DEFF Research Database (Denmark)

Yoshikawa, Hidekazu; Lind, Morten; Yang, Ming

2012-01-01

A new method of risk monitor system of a nuclear power plant has been proposed from the aspect by what degree of safety functions incorporated in the plant system is maintained by multiple barriers of defense-in-depth (DiD). Wherein, the central idea is plant DiD risk monitor and reliability...... monitor derived from the four aspects of (i) design principle of nuclear safety to realize DiD concept, (ii) definition of risk and risk to be monitored, (iii) severe accident phenomena as major risk, (iv) scheme of risk ranking, and (v) dynamic risk display. In this paper, the overall frame...... of the proposed frame on risk monitor system is summarized and the detailed discussion is made on the definitions of major terminologies of risk, risk ranking, anatomy of fault occurrence, two-layer configuration of risk monitor, how to configure individual elements of plant DiD risk monitor and its example...

Summary of FY 1997 work related to JAPC-U.S. DOE contract study on improvement of core safety - study on GEM (III)

International Nuclear Information System (INIS)

Burke, T.M.

1998-01-01

FFTF was originally designed/constructed/operated to develop LMFBR fuels and materials. Inherent safety became a major focus of the US nuclear industry in the mid 1980's. The inherent safety characteristics of LMFBRs were recognized but additional enhancement was desired. The presentation contents are: Fast Flux Test Facility history and status; Overview of contract activities; Summary of loss of flow without scram with GEMs testing; and Summary of pump start with GEMs testing

Configuration of risk monitor system by plant defense-in-depth risk monitor and reliability monitor

International Nuclear Information System (INIS)

Yoshikawa, Hidekazu; Lind Morten; Yang Ming; Hashim Muhammad; Zhang Zhijian

2012-01-01

A new method of risk monitor system of a nuclear power plant has been proposed from the aspect by what degree of safety functions incorporated in the plant system is maintained by multiple barriers of defense-in-depth (DiD). Wherein, the central idea is plant DiD risk monitor and reliability monitor derived from the five aspects of (1) design principle of nuclear safety based on DiD concept, (2) definition of risk and risk to be monitored, (3) severe accident phenomena as major risk, (4) scheme of risk ranking, and (5) dynamic risk display. In this paper, the overall frame of the proposed risk monitor system is summarized and the detailed discussion is made on major items such as definition of risk and risk ranking, anatomy of fault occurrence, two-layer configuration of risk monitor, how to configure individual elements of plant DiD risk monitor, and lastly how to apply for a PWR safety system. (author)

3MeerLICHT and BlackGEM: custom-built telescopes to detect faint optical transients

NARCIS (Netherlands)

Bloemen, S. (Steven); Groot, P.J. (Paul J.); Woudt, P. (Patrick); Wolt, M.K. (Marc Klein); Mcbride, V. (Vanessa); Nelemans, G. (Gijs); Körding, E. (Elmar); Pretorius, M.L. (Magaretha L.); Roelfsema, R. (Ronald); Bettonvil, F. (Felix); Balster, H. (Harry); Bakker, R. (Roy); Dolron, P. (Peter); Van Elteren, A. (Arjen); Elswijk, E. (Eddy); Engels, A. (Arno); R.P. Fender; Fokker, M. (Marc); Haan, M. (Menno De); Hagoort, K. (Klaas); De Hoog, J. (Jasper); Horst, R.T. (Rik Ter); Van Der Kevie, G. (Giel); Lowski, S.L.K. (Stanis Law Koz); Kragt, J. (Jan); Lech, G. (Grzegorz); Le Poole, R. (Rudolf); Lesman, D. (Dirk); J. Morren (Johan); Navarro, R. (Ramon); Paalberends, W.-J. (Willem-Jelle); K.G. Paterson (Kerry); Laszek, R.P. (Rafal Paw); Pessemier, W. (Wim); Raskin, G. (Gert); Rutten, H. (Harrie); L.H.A. Scheers (Bart); Schuil, M. (Menno); Sybilski, P.W. (Piotr W.)

2016-01-01

textabstractWe present the MeerLICHT and BlackGEM telescopes, which are wide-field optical telescopes that are currently being built to study transient phenomena, gravitational wave counterparts and variable stars. The telescopes have 65 cm primary mirrors and a 2.7 square degree field-of-view. The

The Danish Marine Monitoring System

DEFF Research Database (Denmark)

Ærtebjerg, G.

1997-01-01

Indeholder abstracts fra Workshop on Marine Monitoring Systems and Technology, Risø, 17-18 April 1996.......Indeholder abstracts fra Workshop on Marine Monitoring Systems and Technology, Risø, 17-18 April 1996....

Computer-controlled radiation monitoring system

International Nuclear Information System (INIS)

Homann, S.G.

1994-01-01

A computer-controlled radiation monitoring system was designed and installed at the Lawrence Livermore National Laboratory's Multiuser Tandem Laboratory (10 MV tandem accelerator from High Voltage Engineering Corporation). The system continuously monitors the photon and neutron radiation environment associated with the facility and automatically suspends accelerator operation if preset radiation levels are exceeded. The system has proved reliable real-time radiation monitoring over the past five years, and has been a valuable tool for maintaining personnel exposure as low as reasonably achievable

Corrosion Monitoring System

Energy Technology Data Exchange (ETDEWEB)

Dr. Russ Braunling

2004-10-31

The Corrosion Monitoring System (CMS) program developed and demonstrated a continuously on-line system that provides real-time corrosion information. The program focused on detecting pitting corrosion in its early stages. A new invention called the Intelligent Ultrasonic Probe (IUP) was patented on the program. The IUP uses ultrasonic guided waves to detect small defects and a Synthetic Aperture Focusing Technique (SAFT) algorithm to provide an image of the pits. Testing of the CMS demonstrated the capability to detect pits with dimensionality in the sub-millimeter range. The CMS was tested in both the laboratory and in a pulp and paper industrial plant. The system is capable of monitoring the plant from a remote location using the internet.

gem-Difluoroolefination of Diazo Compounds with TMSCF3 or TMSCF2Br: Transition-Metal-Free Cross-Coupling of Two Carbene Precursors.

Science.gov (United States)

Hu, Mingyou; Ni, Chuanfa; Li, Lingchun; Han, Yongxin; Hu, Jinbo

2015-11-18

A new olefination protocol for transition-metal-free cross-coupling of two carbene fragments arising from two different sources, namely, a nonfluorinated carbene fragment resulting from a diazo compound and a difluorocarbene fragment derived from Ruppert-Prakash reagent (TMSCF3) or TMSCF2Br, has been developed. This gem-difluoroolefination proceeds through the direct nucleophilic addition of diazo compounds to difluorocarbene followed by elimination of N2. Compared to previously reported Cu-catalyzed gem-difluoroolefination of diazo compounds with TMSCF3, which possesses a narrow substrate scope due to a demanding requirement on the reactivity of diazo compounds and in-situ-generated CuCF3, this transition-metal-free protocol affords a general and efficient approach to various disubstituted 1,1-difluoroalkenes, including difluoroacrylates, diaryldifluoroolefins, as well as arylalkyldifluoroolefins. In view of the ready availability of diazo compounds and difluorocarbene reagents and versatile transformations of 1,1-difluoroalkenes, this new gem-difluoroolefination method is expected to find wide applications in organic synthesis.

Study on the novel neutron-to-proton convertor for improving the detection efficiency of a triple GEM based fast neutron detector

International Nuclear Information System (INIS)

Wang Xiaodong; Yang Lei; Zhang Chunhui; Hu Bitao; Yang Herun; Zhang Junwei; Ren Zhongguo; Ha Ri-Ba-La; An Luxing

2015-01-01

A high-efficiency fast neutron detector prototype based on a triple Gas Electron Multiplier (GEM) detector, which, coupled with a novel multi-layered high-density polyethylene (HDPE) as a neutron-to-proton converter for improving the neutron detection efficiency, is introduced and tested with the Am-Be neutron source in the Institute of Modern Physics (IMP) at Lanzhou in the present work. First, the developed triple GEM detector is tested by measuring its effective gain and energy resolution with "5"5Fe X-ray source to ensure that it has a good performance. The effective gain and obtained energy resolution is 5.0 × 10"4 and around 19.2%, respectively. Secondly, the novel multi-layered HDPE converter is coupled with the cathode of the triple GEM detector making it a high-efficiency fast neutron detector. Its effective neutron response is four times higher than that of the traditional single-layered conversion technique when the converter layer number is 38. (authors)

Tomographic capabilities of the new GEM based SXR diagnostic of WEST

Czech Academy of Sciences Publication Activity Database

Jardin, A.; Mazon, D.; O’Mullane, M.; Mlynář, Jan; Löffelmann, Viktor; Imríšek, Martin; Chernyshova, M.; Czarski, T.; Kasprowicz, G.; Wojenski, A.; Bourdelle, C.; Malard, P.

2016-01-01

Roč. 11, July (2016), č. článku C07006. ISSN 1748-0221. [International Conference Frontiers in Diagnostics fix Technologies (ICFDT4). Frascati (Rome), 30.03.2016-01.04.2016] Institutional support: RVO:61389021 Keywords : GEM * SXR * tomography * plasma diagnostics Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: 2.11 Other engineering and technologies Impact factor: 1.220, year: 2016 http://iopscience.iop.org/article/10.1088/1748-0221/11/07/C07006/pdf

Gas House Autonomous System Monitoring

Science.gov (United States)

Miller, Luke; Edsall, Ashley

2015-01-01

Gas House Autonomous System Monitoring (GHASM) will employ Integrated System Health Monitoring (ISHM) of cryogenic fluids in the High Pressure Gas Facility at Stennis Space Center. The preliminary focus of development incorporates the passive monitoring and eventual commanding of the Nitrogen System. ISHM offers generic system awareness, adept at using concepts rather than specific error cases. As an enabler for autonomy, ISHM provides capabilities inclusive of anomaly detection, diagnosis, and abnormality prediction. Advancing ISHM and Autonomous Operation functional capabilities enhances quality of data, optimizes safety, improves cost effectiveness, and has direct benefits to a wide spectrum of aerospace applications.

The UF GEM Research Center Mobile Terrestrial Laser Scanner System M-TLSS Applied to Beach Morphology Studies in St. Augustine, Florida.

Science.gov (United States)

Fernandez, J. C.; Shrestha, R. L.; Carter, W. E.; Slatton, C. K.; Singhania, A.

2006-12-01

The UF GEM Research Center is working towards developing a Mobile Terrestrial Laser Scanning System (M- TLSS). The core of the M-TLSS is a commercial 2-axis ground based laser scanner, Optech ILRIS-36D, which is capable of generating XYZ with laser intensity or RGB textured point clouds in a range from 3m to 1500m. The laser operates at a wavelength of 1535 nm. The sample separation can be adjusted down to 0.00115°, and the scanning speed is 2,000 points per second. The scanner is integrated to a mobile telescoping, rotating and tilting platform which is essentially a telescopic lift mounted on the back of a pick up truck. This provides up to 6 degrees of freedom for performing scanning operations. A scanner built-in 6 megapixel digital camera and a digital video camera provide the M-TLSS moving and still imagining capability. The applications of the M-TLSS data sets are numerous in both the fields of science and engineering. This paper will focus on the application of M-TLSS as a complement to ALSM in the study of beach morphology in the St. Augustine, Florida area. ALSM data covers a long stretch of beach with a moderate sample density of approximately 1 laser return per square meter, which enables the detection of submeter-scale changes in shoreline position and dune heights over periods of few months. The M-TLSS, on the other hand, can provide high density point clouds (centimeter scale point spacing) of smaller areas known to be highly prone to erosion. From these point clouds centimeter level surface grids are created. These grids will be compared with the ALSM data and with a time series of M-TLSS data over the same area to provide high resolution, short term beach erosion monitoring. Surface morphological parameters that will be compared among the ALSM and M-TLSS data sets include shoreline position and gradients and standard deviations of elevations on cross- shore transects.

Coolant monitoring systems for PWR reactors

International Nuclear Information System (INIS)

Luzhnov, A.M.; Morozov, V.V.; Tsypin, S.G.

1987-01-01

The ways of improving information capacity of existing monitoring systems and the necessity of designing new ones for coolant monitoring are reviewed. A wide research program on development of coolant monitoring systems in PWR reactors is analyzed. The possible applications of in-core and out-of-core detectors for coolant monitoring are demonstrated

Monitoring of Danish marketed solar heating systems

International Nuclear Information System (INIS)

Ellehauge, K.

1993-01-01

The paper describes the monitoring of manufactured solar heating systems for domestic hot water combined with space heating and systems for domestic hot water only. Results from the monitoring of 5 marketed combined systems for domestic hot water and space heating are presented. The systems situated at one family houses at different sites in Denmark have been monitored from January/February 1992. For the detailed monitoring of manufactured systems only for domestic hot water a test facility for simultaneous monitoring of 5 solar heating systems has been established at the Thermal Insulation Laboratory. (au)

Radiation monitor system for nuclear power plants

International Nuclear Information System (INIS)

Wu Bingzhe; Guo Shusheng

1990-12-01

The system has 8 kinds of radiation monitors and 2 stage microcomputers designed for processing the data from each monitor, storaging the information, printing out and displaying on the colour CRT. The function of the system includes high-value alarm, warm alarm and failure alarm, so called t hree-level alarms . Two functions of the alarms are the threshold alarm and the tendency alarm, so that this system is an intelligency system. This system has high reliability and very wide range when LOCA accident takes place. It is aseismic and immune to industrial interference. The system can meet IEC-761-1 standard and is of nuclear safety 3rd class. Also the following monitors were designed: 133 Xe monitor, 131 I monitor, low-level liquid monitor and high radiation γ area monitor. The system can meet the requirements of nuclear power plants

Monitoring system and methods for a distributed and recoverable digital control system

Science.gov (United States)

Stange, Kent (Inventor); Hess, Richard (Inventor); Kelley, Gerald B (Inventor); Rogers, Randy (Inventor)

2010-01-01

A monitoring system and methods are provided for a distributed and recoverable digital control system. The monitoring system generally comprises two independent monitoring planes within the control system. The first monitoring plane is internal to the computing units in the control system, and the second monitoring plane is external to the computing units. The internal first monitoring plane includes two in-line monitors. The first internal monitor is a self-checking, lock-step-processing monitor with integrated rapid recovery capability. The second internal monitor includes one or more reasonableness monitors, which compare actual effector position with commanded effector position. The external second monitor plane includes two monitors. The first external monitor includes a pre-recovery computing monitor, and the second external monitor includes a post recovery computing monitor. Various methods for implementing the monitoring functions are also disclosed.

A Grid job monitoring system

Energy Technology Data Exchange (ETDEWEB)

Dumitrescu, Catalin [Fermi National Accelerator Laboratory (United States); Nowack, Andreas [RWTH Aachen (Germany); Padhi, Sanjay [University of California San Diego (United States); Sarkar, Subir, E-mail: subir.sarkar@cern.c [INFN, Sezione di Pisa and Scuola Normale Superiore, Pisa (Italy)

2010-04-01

This paper presents a web-based Job Monitoring framework for individual Grid sites that allows users to follow in detail their jobs in quasi-real time. The framework consists of several independent components : (a) a set of sensors that run on the site CE and worker nodes and update a database, (b) a simple yet extensible web services framework and (c) an Ajax powered web interface having a look-and-feel and control similar to a desktop application. The monitoring framework supports LSF, Condor and PBS-like batch systems. This is one of the first monitoring systems where an X.509 authenticated web interface can be seamlessly accessed by both end-users and site administrators. While a site administrator has access to all the possible information, a user can only view the jobs for the Virtual Organizations (VO) he/she is a part of. The monitoring framework design supports several possible deployment scenarios. For a site running a supported batch system, the system may be deployed as a whole, or existing site sensors can be adapted and reused with the web services components. A site may even prefer to build the web server independently and choose to use only the Ajax powered web interface. Finally, the system is being used to monitor a glideinWMS instance. This broadens the scope significantly, allowing it to monitor jobs over multiple sites.

A grid job monitoring system

International Nuclear Information System (INIS)

Dumitrescu, Catalin; Nowack, Andreas; Padhi, Sanjay; Sarkar, Subir

2010-01-01

This paper presents a web-based Job Monitoring framework for individual Grid sites that allows users to follow in detail their jobs in quasi-real time. The framework consists of several independent components: (a) a set of sensors that run on the site CE and worker nodes and update a database, (b) a simple yet extensible web services framework and (c) an Ajax powered web interface having a look-and-feel and control similar to a desktop application. The monitoring framework supports LSF, Condor and PBS-like batch systems. This is one of the first monitoring systems where an X.509 authenticated web interface can be seamlessly accessed by both end-users and site administrators. While a site administrator has access to all the possible information, a user can only view the jobs for the Virtual Organizations (VO) he/she is a part of. The monitoring framework design supports several possible deployment scenarios. For a site running a supported batch system, the system may be deployed as a whole, or existing site sensors can be adapted and reused with the web services components. A site may even prefer to build the web server independently and choose to use only the Ajax powered web interface. Finally, the system is being used to monitor a glideinWMS instance. This broadens the scope significantly, allowing it to monitor jobs over multiple sites.

The CUORE slow monitoring systems

Science.gov (United States)

Gladstone, L.; Biare, D.; Cappelli, L.; Cushman, J. S.; Del Corso, F.; Fujikawa, B. K.; Hickerson, K. P.; Moggi, N.; Pagliarone, C. E.; Schmidt, B.; Wagaarachchi, S. L.; Welliver, B.; Winslow, L. A.

2017-09-01

CUORE is a cryogenic experiment searching primarily for neutrinoless double decay in 130Te. It will begin data-taking operations in 2016. To monitor the cryostat and detector during commissioning and data taking, we have designed and developed Slow Monitoring systems. In addition to real-time systems using LabVIEW, we have an alarm, analysis, and archiving website that uses MongoDB, AngularJS, and Bootstrap software. These modern, state of the art software packages make the monitoring system transparent, easily maintainable, and accessible on many platforms including mobile devices.

A new front-end ASIC for GEM detectors with time and charge measurement capabilities

Science.gov (United States)

Ciciriello, F.; Corsi, F.; De Robertis, G.; Felici, G.; Loddo, F.; Marzocca, C.; Matarrese, G.; Ranieri, A.

2016-07-01

A 32 channel CMOS front-end ASIC has been designed to read out the GEM detectors intended to be used for beam monitoring in a new proton-therapy facility currently under construction. In order to improve the spatial resolution by exploiting charge centroid algorithms, the analog channels, based on the classic CSA+shaper architecture, are equipped with a peak detector (PD) which works as an analog memory during the read-out phase. The outputs of the PDs are multiplexed towards an integrated 8-bit subranging ADC. An accurate trigger signal marks the arrival of a valid event and is generated by fast-ORing the outputs of 32 voltage discriminators which compare the shaper outputs with a programmable threshold. The digital part of the ASIC manages the read-out of the channels, the A/D conversion and the configuration of the ASIC. A 100 Mbit/s LVDS serial link is used for data communication. The sensitivity of the analog channel is 15 mV/fC and the dynamic range is 80 fC. The simulated ENC is about 650 e- for a detector capacitance of 10 pF.

A new front-end ASIC for GEM detectors with time and charge measurement capabilities

Energy Technology Data Exchange (ETDEWEB)

Ciciriello, F., E-mail: fabio.ciciriello@poliba.it [DEI-Politecnico di Bari, Via Orabona 4, I-70125 Bari (Italy); INFN, Sezione di Bari, Via Orabona 4, I-70125 Bari (Italy); Corsi, F. [DEI-Politecnico di Bari, Via Orabona 4, I-70125 Bari (Italy); INFN, Sezione di Bari, Via Orabona 4, I-70125 Bari (Italy); De Robertis, G. [INFN, Sezione di Bari, Via Orabona 4, I-70125 Bari (Italy); Felici, G. [INFN, Laboratori Nazionali di Frascati, Via E. Fermi 40, I-00044 Frascati (Italy); Loddo, F. [INFN, Sezione di Bari, Via Orabona 4, I-70125 Bari (Italy); Marzocca, C.; Matarrese, G. [DEI-Politecnico di Bari, Via Orabona 4, I-70125 Bari (Italy); INFN, Sezione di Bari, Via Orabona 4, I-70125 Bari (Italy); Ranieri, A. [INFN, Sezione di Bari, Via Orabona 4, I-70125 Bari (Italy)

2016-07-11

A 32 channel CMOS front-end ASIC has been designed to read out the GEM detectors intended to be used for beam monitoring in a new proton-therapy facility currently under construction. In order to improve the spatial resolution by exploiting charge centroid algorithms, the analog channels, based on the classic CSA+shaper architecture, are equipped with a peak detector (PD) which works as an analog memory during the read-out phase. The outputs of the PDs are multiplexed towards an integrated 8-bit subranging ADC. An accurate trigger signal marks the arrival of a valid event and is generated by fast-ORing the outputs of 32 voltage discriminators which compare the shaper outputs with a programmable threshold. The digital part of the ASIC manages the read-out of the channels, the A/D conversion and the configuration of the ASIC. A 100 Mbit/s LVDS serial link is used for data communication. The sensitivity of the analog channel is 15 mV/fC and the dynamic range is 80 fC. The simulated ENC is about 650 e{sup −} for a detector capacitance of 10 pF. © 2001 Elsevier Science. All rights reserved.

An intelligent fetal monitoring system

International Nuclear Information System (INIS)

Inaba, J.; Akatsuka, T.; Kubo, T.; Iwasaki, H.

1986-01-01

An intelligent monitoring system is constructed by a multi-micro-computer system. The monitoring signals are fetal heart rate (FHR) and uterine contraction (UC) through the conventional monitoring device for a day until the delivery. These signals are fed to a micro-computer in digital format, and evaluated by the computer in real time according to the diagnostic algorithm of the expert physician. Monitoring signals are always displayed on the CRT screen and in the case of dangerous state of the fetus, warning signal will appear on the screen and the doctor or nurse will be called. All these signals are sent to the next micro-computer with 10MB hard disk system. On this computer, the doctor and nurse can retrieve and inspect the details of the process by clock-key and/or events-key. After finishing monitoring process, summarized report is constructed and printed out on the paper

CSC large panel R ampersand D summary for the SSC GEM muon subsystem

International Nuclear Information System (INIS)

Pratuch, S.M.; Clements, J.W.; Spellman, G.P.

1994-05-01

The GEM Detector uses 1,128 Cathode Strip Chamber (CSC) muon detectors requiring a total of approximately 10,000 precision panels in the CSC assemblies. These panels must be fabricated to extreme tolerances in order to meet the physics requirement. A fabrication technique used to produce two large panels, nominally 1 by 3 meters, is described and the resulting panel precision is reported

Distributed Monitoring System Based on ICINGA

CERN Multimedia

Haen, C; Neufeld, N

2011-01-01

The LHCb online system relies on a large and heterogeneous I.T. infrastructure : it comprises more than 2000 servers and embedded systems and more than 200 network devices. While for the control and monitoring of detectors, PLCs, and readout boards an industry standard SCADA system PVSSII has been put in production, we use a low level monitoring system to monitor the control infrastructure itself. While our previous system was based on a single central NAGIOS server, our current system uses a distributed ICINGA infrastructure.

GTA Beamloss-Monitor System

International Nuclear Information System (INIS)

Rose, C.R.; Fortgang, C.M.; Power, J.P.

1992-01-01

The GTA Beamless-Monitor System at Los Alamos National Laboratory has been designed to detect high-energy particle loss in the accelerator beamline and shut down the accelerator before any damage can occur. To do this, the Beamless-Monitor System measures the induced gamma radiation, from (p, γ) reactions, at 15 selected points along the beamline, converts this measured radiation to electrical signals integrates and compares them to preset limits, and, in the event of an over-limit condition causes the Fast-Protect System to shut down the entire accelerator. The system dynamic range exceeds 70 dB which will enable experimenters to use the Beamless-Monitor System to help steer the beam as well as provide signals for a Fast-Protect System. The system response time is less than 7 μs assuming a step-function, worst-case beam spill of 50 mA. The system resolution, based on the noise floor of the electronics is about 1.3 mRads/s. Production units have been built and meet the above specifications. The remainder of the system will be installed and tested later in 1992/1993 with the GTA accelerator. The ionization chamber sensitivity and response time are described in the paper

GTA beamloss-monitor system

International Nuclear Information System (INIS)

Rose, C.R.; Fortgang, C.M.; Power, J.P.

1992-01-01

The GTA Beamloss-Monitor System at Los Alamos National Laboratory has been designed to detect high-energy particle loss in the accelerator beamline and shut down the accelerator before any damage can occur. To do this, the Beamloss-Monitor System measures the induced gamma radiation, from (p,γ) reactions, at 15 selected points along the beamline, converts this measured radiation to electrical signals, integrates and compares them to preset limits, and, in the event of an over-limit condition causes the Fast-Protect System to shut down the entire accelerator. The system dynamic range exceeds 70 dB which will enable experimenters to use the Beamloss-Monitor System to help steer the beam as well as provide signals for a Fast-Protect System. The system response time is less than 7 μs assuming a step-function, worst-case beam spill of 50 mA. The system resolution, based on the noise floor of the electronics, is about 1.3 mRads/s. Production units have been built and meet the above specifications. The remainder of the system will be installed and tested later in 1992/93 with the GTA accelerator. The ionization chamber sensitivity and response time are described in the paper. (Author) 4 figs., ref

Operation of a GEM-TPC with pixel readout

CERN Document Server

Brezina, C; Kaminski, J; Killenberg, M; Krautscheid, T

2012-01-01

A prototype time projection chamber with 26 cm drift length was operated with a short-spaced triple gas electron multiplier (GEM) stack in a setup triggering on cosmic muon tracks. A small part of the anode plane is read out with a CMOS pixel application-specified integrated circuit (ASIC) named Timepix, which provides ultimate readout granularity. Pixel clusters of charge depositions corresponding to single primary electrons are observed and analyzed to reconstruct charged particle tracks. A dataset of several weeks of cosmic ray data is analyzed. The number of clusters per track length is well described by simulation. The obtained single point resolution approaches 50 m at short drift distances and is well reproduced by a simple model of single-electron diffusion.

Offsite emergency radiological monitoring system and technology

International Nuclear Information System (INIS)

Mao Yongze

1994-01-01

The study and advance of the offsite radiological monitoring system and technology which is an important branch in the field of nuclear monitoring technology are described. The author suggests that the predicting and measuring system should be involved in the monitoring system. The measuring system can further be divided into four sub-systems, namely plume exposure pathway, emergency worker, ingestion exposure pathway and post accident recovery measuring sub-systems. The main facilities for the monitoring system are concluded as one station, one helicopter, one laboratory and two vehicles. The instrumentation for complement of the facilities and their good performance characteristics, up-to-date technology are also introduced in brief. The offsite emergency radiation monitoring system and technology are compared in detail with those recommended by FEMA U.S.A.. Finally the paper discusses some trends in development of emergency radiation monitoring system and technology in the developed countries

Control and supervision of a time projection chamber with GEM readout

International Nuclear Information System (INIS)

Kaiser, David

2014-01-01

To get a deeper understanding of the structure of nucleons and the strong interaction binding the constituents inside, the CBELSA/TAPS experiment investigates the resonance spectrum of baryons by meson photoproduction within the scope of the SFB/TRR 16 ''Subnuclear Structure of Matter''. In order to support and expand the physical program, the existing Inner Detector will be replaced by a Time Projection Chamber (TPC) within the next few years. This allows for the detection of charged reaction channels, which can't be measured with the CBELSA/TAPS experiment up to now, as well as for particle identification from the specific energy loss. A First prototype with GEM foils for charge amplification in front of the readout plane and suitable size for the CBELSA/TAPS experiment was built in collaboration with the TU Munich, the detector laboratory of the GSI in Darmstadt and the Stefan-Meyer-Institute of the University Vienna. The TPC has been commissioned successfully within the FOPI experiment at the GSI during several test beam campaigns. Additionally, systematic studies have been carried out with a smaller Test-TPC using a TestBench providing an accurate external track definition. As the electron drift velocity in the TPC volume is a crucial parameter for the exact track reconstruction, detailed simulations of the drift velocity and its dependency on external parameters, such as drift voltage, pressure, gas flow or temperature, have been carried out. The results of these simulations recommend a constant monitoring of all examined parameters to allow a reasonable use of the simulated drift velocities. For this purpose, and to ensure a safe and stable operation of the TPCs and the other detectors on the TestBench, the required hardware, the control software based on a data base and a graphical user interface were designed and constructed as the main part of this work. With this so-called SlowControl, it was possible to measure, control and store several parameters - e

Yucca Mountain biological resources monitoring program

International Nuclear Information System (INIS)

1993-02-01

The US Department of Energy (DOE) is required by the Nuclear Waste Policy Act of 1982 (as amended in 1987) to study and characterize Yucca Mountain as a potential site for a geologic repository for high-level nuclear waste. During site characterization, the DOE will conduct a variety of geotechnical, geochemical, geological, and hydrological studies to determine the suitability of Yucca Mountain as a potential repository. To ensure that site characterization activities (SCA) do not adversely affect the environment at Yucca Mountain, an environmental program has been implemented to monitor and mitigate potential impacts and ensure activities comply with applicable environmental regulations. This report describes the activities and accomplishments of EG ampersand G Energy Measurements, Inc. (EG ampersand G/EM) during fiscal year 1992 (FY92) for six program areas within the Terrestrial Ecosystem component of the YMP environmental program. The six program areas are Site Characterization Effects, Desert Tortoises, Habitat Reclamation, Monitoring and Mitigation, Radiological Monitoring, and Biological Support

System specification for the integrated monitoring and surveillance system

International Nuclear Information System (INIS)

1997-09-01

This System Specification establishes the requirements for the Plutonium Focus Area (PFA) Integrated Monitoring and Surveillance System (IMSS). In this document, ''Integrated Monitoring and Surveillance System'' is used to describe the concept of integrated sensors, computers, personnel, and systems that perform the functions of sensing conditions, acquiring data, monitoring environmental safety and health, controlling and accounting for materials, monitoring material stability, monitoring container integrity, transferring data, and analyzing, reporting, and storing data. This concept encompasses systems (e.g. sensors, personnel, databases, etc.) that are already in place at the sites but may require modifications or additions to meet all identified surveillance requirements. The purpose of this System Specification is to provide Department of Energy (DOE) sites that store plutonium materials with a consolidation of all known requirements for the storage and surveillance of 3013 packages of stabilized plutonium metals and oxides. This compilation may be used (1) as a baseline for surveillance system design specifications where 3013 packages of stabilized plutonium metals and oxides will be stored and monitored; (2) as a checklist for evaluating existing surveillance systems to ensure that all requirements are met for the storage and surveillance of 3013 packages of stabilized plutonium metals and oxides; and (3) as a baseline for preparing procurement specifications tailored for site specific storage and surveillance of 3013 packages of stabilized plutonium metals and oxides

ERMS - Environmental Radiation Monitoring System

International Nuclear Information System (INIS)

Vax, Eran; Sarusi, Benny; Sheinfeld, Mati; Levinson, Shmuel; Brandys, Irad; Sattinger, Danny; Wengrowicz, Udi; Tshuva, Avi; Tirosh, Dan

2008-01-01

A new Environmental Radiation Monitoring System (ERMS) has been developed in the NRCN as an extensive tool to be applied in case of nuclear malfunction or Nuclear Disposal Device (NDD) incident, as well as for routine radiation monitoring of the reactor's vicinity. The system collects real-time environmental data such as: gamma radiation, wind speed, wind direction, and temperature for monitoring purposes. The ERMS consists of a main Control Center and an array of monitoring stations. Fixed, environmental, gamma radiation monitoring stations are installed at the reactor's surroundings while portable stations can be posted rapidly along the wind direction, enhancing the spatial sampling of the radiation measurements and providing better hazard assessment at an emergency event. The presented ERMS, based on industrial standards for hardware and network protocols, is a reliable standalone system which upgrades the readiness to face a nuclear emergency event by supplying real-time, integrated meteorological and radiation data. (author)

The gem collection of the Rijksmuseum van Geologie en Mineralogie of Leiden The Peridots

NARCIS (Netherlands)

Zwaan, P.C.

1957-01-01

The peridots in the gem collection of our Museum were acquired a long time ago (part of them were from the collection of King William I of the Netherlands). We should be sceptical about data on the origin of this material. Firstly we do not generally know whether the stones were bought or received

Imaging of high-Z material for nuclear contraband detection with a minimal prototype of a muon tomography station based on GEM detectors

Energy Technology Data Exchange (ETDEWEB)

Gnanvo, Kondo, E-mail: kgnanvo@fit.edu [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL 32901 (United States); Grasso, Leonard V.; Hohlmann, Marcus; Locke, Judson B.; Quintero, Amilkar [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL 32901 (United States); Mitra, Debasis [Department of Computer Sciences, Florida Institute of Technology, Melbourne, FL 32901 (United States)

2011-10-01

Muon Tomography based on the measurement of multiple scattering of atmospheric cosmic ray muons in matter is a promising technique for detecting heavily shielded high-Z radioactive materials (U, Pu) in cargo or vehicles. The technique uses the deflection of cosmic ray muons in matter to perform tomographic imaging of high-Z material inside a probed volume. A Muon Tomography Station (MTS) requires position-sensitive detectors with high spatial resolution for optimal tracking of incoming and outgoing cosmic ray muons. Micro Pattern Gaseous Detector (MPGD) technologies such as Gas Electron Multiplier (GEM) detectors are excellent candidates for this application. We have built and operated a minimal MTS prototype based on 30 cmx30 cm GEM detectors for probing targets with various Z values inside the MTS volume. We report the first successful detection and imaging of medium-Z and high-Z targets of small volumes ({approx}0.03 L) using GEM-based Muon Tomography.

Imaging of high-Z material for nuclear contraband detection with a minimal prototype of a muon tomography station based on GEM detectors

International Nuclear Information System (INIS)

Gnanvo, Kondo; Grasso, Leonard V.; Hohlmann, Marcus; Locke, Judson B.; Quintero, Amilkar; Mitra, Debasis

2011-01-01

Muon Tomography based on the measurement of multiple scattering of atmospheric cosmic ray muons in matter is a promising technique for detecting heavily shielded high-Z radioactive materials (U, Pu) in cargo or vehicles. The technique uses the deflection of cosmic ray muons in matter to perform tomographic imaging of high-Z material inside a probed volume. A Muon Tomography Station (MTS) requires position-sensitive detectors with high spatial resolution for optimal tracking of incoming and outgoing cosmic ray muons. Micro Pattern Gaseous Detector (MPGD) technologies such as Gas Electron Multiplier (GEM) detectors are excellent candidates for this application. We have built and operated a minimal MTS prototype based on 30 cmx30 cm GEM detectors for probing targets with various Z values inside the MTS volume. We report the first successful detection and imaging of medium-Z and high-Z targets of small volumes (∼0.03 L) using GEM-based Muon Tomography.

Trace elemental analysis of Indian natural moonstone gems by PIXE and XRD techniques.

Science.gov (United States)

Venkateswara Rao, R; Venkateswarulu, P; Kasipathi, C; Sivajyothi, S

2013-12-01

A selected number of Indian Eastern Ghats natural moonstone gems were studied with a powerful nuclear analytical and non-destructive Proton Induced X-ray Emission (PIXE) technique. Thirteen elements, including V, Co, Ni, Zn, Ga, Ba and Pb, were identified in these moonstones and may be useful in interpreting the various geochemical conditions and the probable cause of their inceptions in the moonstone gemstone matrix. Furthermore, preliminary XRD studies of different moonstone patterns were performed. The PIXE technique is a powerful method for quickly determining the elemental concentration of a substance. A 3MeV proton beam was employed to excite the samples. The chemical constituents of moonstones from parts of the Eastern Ghats geological formations of Andhra Pradesh, India were determined, and gemological studies were performed on those gems. The crystal structure and the lattice parameters of the moonstones were estimated using X-Ray Diffraction studies, trace and minor elements were determined using the PIXE technique, and major compositional elements were confirmed by XRD. In the present work, the usefulness and versatility of the PIXE technique for research in geo-scientific methodology is established. © 2013 Elsevier Ltd. All rights reserved.

The Pajarito Monitor: a high-sensitivity monitoring system for highly enriched uranium

International Nuclear Information System (INIS)

Fehlau, P.E.; Coop, K.; Garcia, C.; Martinez, J.

1984-01-01

The Pajarito Monitor for Special Nuclear Material is a high-sensitivity gamma-ray monitoring system for detecting small quantities of highly enriched uranium transported by pedestrians or motor vehicles. The monitor consists of two components: a walk-through personnel monitor and a vehicle monitor. The personnel monitor has a plastic-scintillator detector portal, a microwave occupancy monitor, and a microprocessor control unit that measures the radiation intensity during background and monitoring periods to detect transient diversion signals. The vehicle monitor examines stationary motor vehicles while the vehicle's occupants pass through the personnel portal to exchange their badges. The vehicle monitor has four groups of large plastic scintillators that scan the vehicle from above and below. Its microprocessor control unit measures separate radiation intensities in each detector group. Vehicle occupancy is sensed by a highway traffic detection system. Each monitor's controller is responsible for detecting diversion as well as serving as a calibration and trouble-shooting aid. Diversion signals are detected by a sequential probability ratio hypothesis test that minimizes the monitoring time in the vehicle monitor and adapts itself well to variations in individual passage speed in the personnel monitor. Designed to be highly sensitive to diverted enriched uranium, the monitoring system also exhibits exceptional sensitivity for plutonium

Energy Doubler cryoloop temperature monitor system

International Nuclear Information System (INIS)

Pucci, G.; Howard, D.

1981-10-01

The Cryoloop Temperature Monitor System is a fully electronic system designed to monitor temperature at key points in the Energy Doubler cryoloop system. It is used for cryoloop diagnostics, temperature studies, and cooldown valve control

Hanger-type laundry monitor system

International Nuclear Information System (INIS)

Aoyama, Kei; Kouno, Yoshio; Yanagishima, Ryouhei; Ikeda, Yasuyuki; Nakatani, Masahiro

1987-01-01

Laundry monitor is installed in nuclear power plants or other nuclear facilities in order to efficiently detect radioactive contamination remains on the surfaces of the working clothes which were used in the controlled area and washed afterward. The number of the working clothes which must be measured has been increasing in accordance with the increase of the nuclear facilities. This fact and recent intensified radiation control require automatic, high-speed and high sensitive measurement. Conveyer-type laundry monitor in which the working clothes are inserted by the metal net conveyer has been generally used, and recently new system with an automatic folder has become more popular. But, this type of system has not so big capacity because the clothes are conveyed longitudinally and also requires considerable wide space when installed. Fuji electric Co., Ltd. has been engaging in research and development for an optimum laundry monitor system used in nuclear facilities since the joint investigation with ten electric power companies in Japan in 1982. Consequently hanger-type laundry monitor system using automatic hanger conveyer was developed and 2 systems were delivered to Chubu Electric Power Co., Ltd. in 1986. This system permits to detect radioactive contamination on the working clothes, pick the contaminated clothes out and fold the uncontaminated clothes fully automatically and continuously. Moreover it allows to shorten the measurement time because the clothes are conveyed transversely and save the installation space, so that this will be regarded as considerably complete system in the world. This report describes the outline of the hanger-type laundry monitor system. (author)

Storage monitoring systems for the year 2000

International Nuclear Information System (INIS)

Nilsen, C.; Pollock, R.

1997-01-01

In September 1993, President Clinton stated the US would ensure that its fissile material meet the highest standards of safety, security, and international accountability. Frequent human inspection of the material could be used to ensure these standards. However, it may be more effective and less expensive to replace these manual inspections with virtual inspections via remote monitoring technologies. To prepare for this future, Sandia National Laboratories has developed several monitoring systems, including the Modular Integrated Monitoring System (MIMS) and Project Straight-Line. The purpose of this paper is to describe a Sandia effort that merges remote monitoring technologies into a comprehensive storage monitoring system that will meet the near-term as well as the long-term requirements for these types of systems. Topics discussed include: motivations for storage monitoring systems to include remote monitoring; an overview of the needs and challenges of providing a storage monitoring system for the year 2000; an overview of how the MIMS and Straight-Line can be enhanced so that together they create an integrated and synergistic information system by the end of 1997; and suggested milestones for 1998 and 1999 to assure steady progress in preparing for the needs of 2000

Performance Monitoring Applied to System Supervision

Directory of Open Access Journals (Sweden)

Bertille Somon

2017-07-01

Full Text Available Nowadays, automation is present in every aspect of our daily life and has some benefits. Nonetheless, empirical data suggest that traditional automation has many negative performance and safety consequences as it changed task performers into task supervisors. In this context, we propose to use recent insights into the anatomical and neurophysiological substrates of action monitoring in humans, to help further characterize performance monitoring during system supervision. Error monitoring is critical for humans to learn from the consequences of their actions. A wide variety of studies have shown that the error monitoring system is involved not only in our own errors, but also in the errors of others. We hypothesize that the neurobiological correlates of the self-performance monitoring activity can be applied to system supervision. At a larger scale, a better understanding of system supervision may allow its negative effects to be anticipated or even countered. This review is divided into three main parts. First, we assess the neurophysiological correlates of self-performance monitoring and their characteristics during error execution. Then, we extend these results to include performance monitoring and error observation of others or of systems. Finally, we provide further directions in the study of system supervision and assess the limits preventing us from studying a well-known phenomenon: the Out-Of-the-Loop (OOL performance problem.

CtGEM typing: Discrimination of Chlamydia trachomatis ocular and urogenital strains and major evolutionary lineages by high resolution melting analysis of two amplified DNA fragments.

Science.gov (United States)

Giffard, Philip M; Andersson, Patiyan; Wilson, Judith; Buckley, Cameron; Lilliebridge, Rachael; Harris, Tegan M; Kleinecke, Mariana; O'Grady, Kerry-Ann F; Huston, Wilhelmina M; Lambert, Stephen B; Whiley, David M; Holt, Deborah C

2018-01-01

Chlamydia trachomatis infects the urogenital tract (UGT) and eyes. Anatomical tropism is correlated with variation in the major outer membrane protein encoded by ompA. Strains possessing the ocular ompA variants A, B, Ba and C are typically found within the phylogenetically coherent "classical ocular lineage". However, variants B, Ba and C have also been found within three distinct strains in Australia, all associated with ocular disease in children and outside the classical ocular lineage. CtGEM genotyping is a method for detecting and discriminating ocular strains and also the major phylogenetic lineages. The rationale was facilitation of surveillance to inform responses to C. trachomatis detection in UGT specimens from young children. CtGEM typing is based on high resolution melting analysis (HRMA) of two PCR amplified fragments with high combinatorial resolving power, as defined by computerised comparison of 65 whole genomes. One fragment is from the hypothetical gene defined by Jali-1891 in the C. trachomatis B_Jali20 genome, while the other is from ompA. Twenty combinatorial CtGEM types have been shown to exist, and these encompass unique genotypes for all known ocular strains, and also delineate the TI and T2 major phylogenetic lineages, identify LGV strains and provide additional resolution beyond this. CtGEM typing and Sanger sequencing were compared with 42 C. trachomatis positive clinical specimens, and there were no disjunctions. CtGEM typing is a highly efficient method designed and tested using large scale comparative genomics. It divides C. trachomatis into clinically and biologically meaningful groups, and may have broad application in surveillance.

Use of Excel ion exchange equilibrium solver with WinGEMS to model and predict NPE distribution in the Mead/Westvaco Evandale, TX, hardwood bleach plant

Science.gov (United States)

Christopher Litvay; Alan Rudie; Peter Hart

2003-01-01

An Excel spreadsheet developed to solve the ion-exchange equilibrium in wood pulps has been linked by dynamic data exchange to WinGEMS and used to model the non-process elements in the hardwood bleach plant of the Mead/Westvaco Evandale mill. Pulp and filtrate samples were collected from the diffusion washers and final wash press of the bleach plant. A WinGEMS model of...

A Continuously Running High-Rate GEM-TPC for P-bar ANDA

International Nuclear Information System (INIS)

Boehmer, F.V.; Angerer, H.; Dorheim, S.; Hoeppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Vandenbroucke, M.; Zhang, X.; Berger, M.; Cusanno, F.; Fabbietti, L.; Lalik, R.; Beck, R.; Kaiser, D.; Lang, M.; Schmitz, R.; Walther, D.; Winnebeck, A.

2011-01-01

The P-bar ANDA fixed target experiment planned at FAIR will investigate fundamental questions of non-perturbative QCD. It makes use of a cooled antiproton beam (momentum: 1.5 to 15GeV/c) and will reach luminosities of up to 2.10 32 cm -2 s -1 , yielding a p-bar p-annihilation rate of 2.10 7 s -1 . One option for the central tracker of P-bar ANDA is a cylindrical, ungated, continuously running TPC with GEM-based gas amplification stage.

Gems of combinatorial optimization and graph algorithms

CERN Document Server

Skutella, Martin; Stiller, Sebastian; Wagner, Dorothea

2015-01-01

Are you looking for new lectures for your course on algorithms, combinatorial optimization, or algorithmic game theory?  Maybe you need a convenient source of relevant, current topics for a graduate student or advanced undergraduate student seminar?  Or perhaps you just want an enjoyable look at some beautiful mathematical and algorithmic results, ideas, proofs, concepts, and techniques in discrete mathematics and theoretical computer science?   Gems of Combinatorial Optimization and Graph Algorithms is a handpicked collection of up-to-date articles, carefully prepared by a select group of international experts, who have contributed some of their most mathematically or algorithmically elegant ideas.  Topics include longest tours and Steiner trees in geometric spaces, cartograms, resource buying games, congestion games, selfish routing, revenue equivalence and shortest paths, scheduling, linear structures in graphs, contraction hierarchies, budgeted matching problems, and motifs in networks.   This ...

Plant-wide integrated equipment monitoring and analysis system

International Nuclear Information System (INIS)

Morimoto, C.N.; Hunter, T.A.; Chiang, S.C.

2004-01-01

A nuclear power plant equipment monitoring system monitors plant equipment and reports deteriorating equipment conditions. The more advanced equipment monitoring systems can also provide information for understanding the symptoms and diagnosing the root cause of a problem. Maximizing the equipment availability and minimizing or eliminating consequential damages are the ultimate goals of equipment monitoring systems. GE Integrated Equipment Monitoring System (GEIEMS) is designed as an integrated intelligent monitoring and analysis system for plant-wide application for BWR plants. This approach reduces system maintenance efforts and equipment monitoring costs and provides information for integrated planning. This paper describes GEIEMS and how the current system is being upgraded to meet General Electric's vision for plant-wide decision support. (author)

Properties of thick GEM in low-pressure deuterium

International Nuclear Information System (INIS)

Lee, C S; Ota, S; Tokieda, H; Kojima, R; Watanabe, Y N; Uesaka, T

2014-01-01

Deuteron inelastic scattering (d, d') provides a promising spectroscopic tool to study nuclear incompressibility. In studies of deuteron inelastic scattering of unstable nuclei, measurements of low-energy recoiled particles is very important. In order to perform these measurements, we are developing a GEM-TPC based gaseous active target, called CAT (Center for nuclear study Active Target), operated with pure deuterium gas. The CAT has been tested with deuterium gas at 1 atm and 100-μm-thick GEMs. The low-pressure operation of CAT is planned in order to improve the detection capability for lower-energy recoil particles. A 400 μm-thick gas electron multiplier (THGEM) was chosen for the low-pressure operation of CAT. However, the properties of THGEM in low-pressure deuterium are currently undocumented. In this work, the performance of THGEM with low-pressure pure deuterium gas has been investigated. The effective gas gain of THGEM has been measured in various conditions using a 5.5-MeV 241 Am alpha source. The effective gas gain was measured for 0.2-, 0.3- and 0.4-atm deuterium gas and a gas gain of about 10 3 was achieved by a double THGEM structure at 0.2 atm. The maximum achieved gain decreased with increasing gas pressure. The dependences of the effective gas gain on the electric field strengths of the drift, transfer and induction regions were investigated. The gain stability as a function of time in hydrogen gas was also tested and a relaxation time of THGEM of about 60 hours was observed with a continuous irradiation of alpha particles, which is significantly longer than previous studies have reported. We have tried to evaluate the gas gain of THGEM in deuterium gas by considering only the Townsend ionization process; however, it turned out that more phenomenological aspects, such as transfer efficiency, should be included in the evaluation. The basic properties of THGEM in low-pressure deuterium have been investigated for the first time

Properties of thick GEM in low-pressure deuterium

Science.gov (United States)

Lee, C. S.; Ota, S.; Tokieda, H.; Kojima, R.; Watanabe, Y. N.; Uesaka, T.

2014-05-01

Deuteron inelastic scattering (d, d') provides a promising spectroscopic tool to study nuclear incompressibility. In studies of deuteron inelastic scattering of unstable nuclei, measurements of low-energy recoiled particles is very important. In order to perform these measurements, we are developing a GEM-TPC based gaseous active target, called CAT (Center for nuclear study Active Target), operated with pure deuterium gas. The CAT has been tested with deuterium gas at 1 atm and 100-μm-thick GEMs. The low-pressure operation of CAT is planned in order to improve the detection capability for lower-energy recoil particles. A 400 μm-thick gas electron multiplier (THGEM) was chosen for the low-pressure operation of CAT. However, the properties of THGEM in low-pressure deuterium are currently undocumented. In this work, the performance of THGEM with low-pressure pure deuterium gas has been investigated. The effective gas gain of THGEM has been measured in various conditions using a 5.5-MeV 241Am alpha source. The effective gas gain was measured for 0.2-, 0.3- and 0.4-atm deuterium gas and a gas gain of about 103 was achieved by a double THGEM structure at 0.2 atm. The maximum achieved gain decreased with increasing gas pressure. The dependences of the effective gas gain on the electric field strengths of the drift, transfer and induction regions were investigated. The gain stability as a function of time in hydrogen gas was also tested and a relaxation time of THGEM of about 60 hours was observed with a continuous irradiation of alpha particles, which is significantly longer than previous studies have reported. We have tried to evaluate the gas gain of THGEM in deuterium gas by considering only the Townsend ionization process; however, it turned out that more phenomenological aspects, such as transfer efficiency, should be included in the evaluation. The basic properties of THGEM in low-pressure deuterium have been investigated for the first time.

Benzene Monitor System report

International Nuclear Information System (INIS)

Livingston, R.R.

1992-01-01

Two systems for monitoring benzene in aqueous streams have been designed and assembled by the Savannah River Technology Center, Analytical Development Section (ADS). These systems were used at TNX to support sampling studies of the full-scale open-quotes SRAT/SME/PRclose quotes and to provide real-time measurements of benzene in Precipitate Hydrolysis Aqueous (PHA) simulant. This report describes the two ADS Benzene Monitor System (BMS) configurations, provides data on system operation, and reviews the results of scoping tests conducted at TNX. These scoping tests will allow comparison with other benzene measurement options being considered for use in the Defense Waste Processing Facility (DWPF) laboratory. A report detailing the preferred BMS configuration statistical performance during recent tests has been issued under separate title: Statistical Analyses of the At-line Benzene Monitor Study, SCS-ASG-92-066. The current BMS design, called the At-line Benzene Monitor (ALBM), allows remote measurement of benzene in PHA solutions. The authors have demonstrated the ability to calibrate and operate this system using peanut vials from a standard Hydragard trademark sampler. The equipment and materials used to construct the ALBM are similar to those already used in other applications by the DWPF lab. The precision of this system (±0.5% Relative Standard Deviation (RSD) at 1 sigma) is better than the purge ampersand trap-gas chromatograpy reference method currently in use. Both BMSs provide a direct measurement of the benzene that can be purged from a solution with no sample pretreatment. Each analysis requires about five minutes per sample, and the system operation requires no special skills or training. The analyzer's computer software can be tailored to provide desired outputs. Use of this system produces no waste stream other than the samples themselves (i.e. no organic extractants)

On predicting monitoring system effectiveness

Science.gov (United States)

Cappello, Carlo; Sigurdardottir, Dorotea; Glisic, Branko; Zonta, Daniele; Pozzi, Matteo

2015-03-01

While the objective of structural design is to achieve stability with an appropriate level of reliability, the design of systems for structural health monitoring is performed to identify a configuration that enables acquisition of data with an appropriate level of accuracy in order to understand the performance of a structure or its condition state. However, a rational standardized approach for monitoring system design is not fully available. Hence, when engineers design a monitoring system, their approach is often heuristic with performance evaluation based on experience, rather than on quantitative analysis. In this contribution, we propose a probabilistic model for the estimation of monitoring system effectiveness based on information available in prior condition, i.e. before acquiring empirical data. The presented model is developed considering the analogy between structural design and monitoring system design. We assume that the effectiveness can be evaluated based on the prediction of the posterior variance or covariance matrix of the state parameters, which we assume to be defined in a continuous space. Since the empirical measurements are not available in prior condition, the estimation of the posterior variance or covariance matrix is performed considering the measurements as a stochastic variable. Moreover, the model takes into account the effects of nuisance parameters, which are stochastic parameters that affect the observations but cannot be estimated using monitoring data. Finally, we present an application of the proposed model to a real structure. The results show how the model enables engineers to predict whether a sensor configuration satisfies the required performance.

Monitoring in educational development projects : the development of a monitoring system

NARCIS (Netherlands)

Plomp, T.; Huijsman, Hari; Kluyfhout, Eric

1992-01-01

Monitoring in education is usually focused on the monitoring of educational systems at different levels. Monitoring of educational projects receives only recently explicit attention. The paper discusses first the concepts of educational monitoring and evaluation. After that, the experience with

CERN GSM monitoring system

CERN Multimedia

Ghabrous Larrea, C

2009-01-01

As a result of the tremendous development of GSM services over the last years, the number of related services used by organizations has drastically increased. Therefore, monitoring GSM services is becoming a business critical issue in order to be able to react appropriately in case of incident. In order to provide with GSM coverage all the CERN underground facilities, more than 50 km of leaky feeder cable have been deployed. This infrastructure is also used to propagate VHF radio signals for the CERN’s fire brigade. Even though CERN’s mobile operator monitors the network, it cannot guarantee the availability of GSM services, and for sure not VHF services, where signals are carried by the leaky feeder cable. So, a global monitoring system has become critical to CERN. In addition, monitoring this infrastructure will allow to characterize its behaviour over time, especially with LHC operation. Given that commercial solutions were not yet mature, CERN developed a system based on GSM probes and an application...

Lingua(gem sob duas perspectivas teóricas

Directory of Open Access Journals (Sweden)

Lidiomar José Mascarello

2010-02-01

Destacaremos nesse breve percurso teórico dois olhares possíveis para esse fenômeno, a língua(gem, que é tão natural e ao mesmo tempo tão complexo de ser explicado e entendido. De um lado, questões psíquicas individuais, como um processo evolutivo que opera em escala de tempo e que depende da maturação dos processos neurais e de toda rede neuronial e da capacidade inata do sujeito, ou seja, uma visão com tendências mais cognitivista, e por outro, da exposição à interação sócio-ambiental, de cunho interacionista, pois, acreditamos que são complementares e não restritivas ou excludentes.

Remote supervision of GIS monitoring system

Energy Technology Data Exchange (ETDEWEB)

Pannunzio, J.; Juge, P.; Ficheux, A.; Rayon, J.L. [Areva T and D Automation Canada Inc., Monteal, PQ (Canada)

2007-07-01

Operators of gas-insulated substations (GIS) are increasingly concerned with failure prevention, scheduled maintenance, personnel safety and shortage of maintenance crews. Until recently, the density levels of the insulating gas sulfur hexafluoride (SF6) was the only parameter controlled in gas-insulated substations. Modern digital type control and monitoring equipment have been widely used in the past decade. Remote indication of gas density and status of dynamic components was made possible and shown on local control panels. Modern GIS monitoring systems offer features such as SF6 monitoring, SF6 leakage trends, internal arc localization and detection. The required information is recorded in a local computer and displaced onto a local human machine interface (HMI) or a local industrial PC mounted next to the GIS. These monitoring systems are used as decision making tools to facilitate maintenance activities and optimize the management of assets. This paper presented the latest developments in digital monitoring systems in terms of modern digital architecture; management of information flows between monitoring systems and control systems; operation of remote supervision; configuration of high voltage substations and information sharing; and, types of links between GIS room and remote supervision. This paper also demonstrated what can be achieved by moving the central HMI of a GIS monitoring system to the decision-making centres. It was shown that integrated features that allow remote on-line or automated management have reached an acceptable level of reliability and comfort for operators. 5 figs.

Systems analysis programs for hands-on integrated reliability evaluations (SAPHIRE), Version 5.0

International Nuclear Information System (INIS)

Russell, K.D.; Kvarfordt, K.J.; Hoffman, C.L.

1995-10-01

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of several microcomputer programs that were developed to create and analyze probabilistic risk assessments (PRAs), primarily for nuclear power plants. The Graphical Evaluation Module (GEM) is a special application tool designed for evaluation of operational occurrences using the Accident Sequence Precursor (ASP) program methods. GEM provides the capability for an analyst to quickly and easily perform conditional core damage probability (CCDP) calculations. The analyst can then use the CCDP calculations to determine if the occurrence of an initiating event or a condition adversely impacts safety. It uses models and data developed in the SAPHIRE specially for the ASP program. GEM requires more data than that normally provided in SAPHIRE and will not perform properly with other models or data bases. This is the first release of GEM and the developers of GEM welcome user comments and feedback that will generate ideas for improvements to future versions. GEM is designated as version 5.0 to track GEM codes along with the other SAPHIRE codes as the GEM relies on the same, shared database structure

System of message for gamma-radiation monitor

International Nuclear Information System (INIS)

Bolic, M.D.; Koturovic, A.M.

2001-01-01

Paper describes a system of voice messages for gamma-radiation monitor based on PC. The systems reproduces recorded messages that is simpler than the process of their synthesis. Message choice is based on combination of recorded digital results and/or received reference messages or warnings. The system of generation of voice messages applies the Windows based software. The total memory array required to create independent voice system is maximum 1.7 mbyte. The monitor may be used for continuous monitoring of radioactivity level with 5-8 s period of message repetition. Another option of the system operation is based on monitor application for the environment monitoring. Period of messages in this case is equal to 5-30 min [ru

Auto-Ignition of Iso-Stoichiometric Blends of Gasoline-Ethanol-Methanol (GEM) in SI, HCCI and CI Combustion Modes

KAUST Repository

Waqas, Muhammad

2017-03-28

Gasoline-ethanol-methanol (GEM) blends, with constant stoichiometric air-to-fuel ratio (iso-stoichiometric blending rule) and equivalent to binary gasoline-ethanol blends (E2, E5, E10 and E15 in % vol.), were defined to investigate the effect of methanol and combined mixtures of ethanol and methanol when blended with three FACE (Fuels for Advanced Combustion Engines) Gasolines, I, J and A corresponding to RON 70.2, 73.8 and 83.9, respectively, and their corresponding Primary Reference Fuels (PRFs). A Cooperative Fuel Research (CFR) engine was used under Spark Ignition and Homogeneous Charge Compression Ignited modes. An ignition quality tester was utilized in the Compression Ignition mode. One of the promising properties of GEM blends, which are derived using the iso-stoichiometric blending rule, is that they maintain a constant octane number, which has led to the introduction of methanol as a drop-in fuel to supplement bio-derived ethanol. A constant RON/HCCI fuel number/derived Research octane number property was observed in all three combustion modes for high RON fuels, but for low RON fuels, the iso-stoichiometric blending rule for constant octane number did not appear to be valid. The chemical composition and octane number of the base fuel also influenced the behavior of the GEM blends under different conditions.

Auto-Ignition of Iso-Stoichiometric Blends of Gasoline-Ethanol-Methanol (GEM) in SI, HCCI and CI Combustion Modes

KAUST Repository

Waqas, Muhammad; Naser, Nimal; Sarathy, Mani; Feijs, Jeroen; Morganti, Kai; Nyrenstedt, Gustav; Johansson, Bengt

2017-01-01

Gasoline-ethanol-methanol (GEM) blends, with constant stoichiometric air-to-fuel ratio (iso-stoichiometric blending rule) and equivalent to binary gasoline-ethanol blends (E2, E5, E10 and E15 in % vol.), were defined to investigate the effect of methanol and combined mixtures of ethanol and methanol when blended with three FACE (Fuels for Advanced Combustion Engines) Gasolines, I, J and A corresponding to RON 70.2, 73.8 and 83.9, respectively, and their corresponding Primary Reference Fuels (PRFs). A Cooperative Fuel Research (CFR) engine was used under Spark Ignition and Homogeneous Charge Compression Ignited modes. An ignition quality tester was utilized in the Compression Ignition mode. One of the promising properties of GEM blends, which are derived using the iso-stoichiometric blending rule, is that they maintain a constant octane number, which has led to the introduction of methanol as a drop-in fuel to supplement bio-derived ethanol. A constant RON/HCCI fuel number/derived Research octane number property was observed in all three combustion modes for high RON fuels, but for low RON fuels, the iso-stoichiometric blending rule for constant octane number did not appear to be valid. The chemical composition and octane number of the base fuel also influenced the behavior of the GEM blends under different conditions.

Stack Monitoring System At PUSPATI TRIGA Reactor

International Nuclear Information System (INIS)

Zamrul Faizad Omar; Mohd Sabri Minhat; Zareen Khan Abdul Jalil Khan; Ridzuan Abdul Mutalib; Khairulezwan Abdul Manan; Nurfarhana Ayuni Joha; Izhar Abu Hussin

2014-01-01

This paper describes the current Stack Monitoring System at PUSPATI TRIGA Reactor (RTP) building. A stack monitoring system is a continuous air monitor placed at the reactor top for monitoring the presence of radioactive gaseous in the effluent air from the RTP building. The system consists of four detectors that provide the reading for background, particulate, Iodine and Noble gas. There is a plan to replace the current system due to frequent fault of the system, thus thorough understanding of the current system is required. Overview of the whole system will be explained in this paper. Some current results would be displayed and moving forward brief plan would be mentioned. (author)

Digital radiation monitor system

International Nuclear Information System (INIS)

Quan Jinhu; Zhai Yongchun; Guan Junfeng; Ren Dangpei; Ma Zhiyuan

2003-01-01

The article introduced digital radiation monitor system. The contents include: how to use advanced computer net technology to establish equipment net for nuclear facility, how to control and manage measuring instruments on field equipment net by local area net, how to manage and issue radiation monitoring data by internet

Monsoon-driven transport of atmospheric mercury to the South China Sea from the Chinese mainland and Southeast Asia-Observation of gaseous elemental mercury at a background station in South China.

Science.gov (United States)

Liu, Ming; Chen, Laiguo; Xie, Donghai; Sun, Jiaren; He, Qiusheng; Cai, Limei; Gao, Zhiqiang; Zhang, Yiqiang

2016-11-01

Concentrations of gaseous elemental mercury (GEM) were continuously monitored from May 2011 to May 2012 at the Wuzhishan State Atmosphere Background Monitoring Station (109°29'30.2″ E, 18°50'11.0″ N) located in Hainan Island. This station is an ideal site for monitoring long-range transport of atmospheric pollutants from mainland China and Southeast Asia to South China Sea. Annual average GEM concentration was 1.58 ± 0.71 ng m -3 during the monitoring period, which was close to background values in the Northern Hemisphere. GEM concentrations showed a clear seasonal variation with relatively higher levels in autumn (1.86 ± 0.55 ng m -3 ) and winter (1.80 ± 0.62 ng m -3 ) and lower levels in spring (1.16 ± 0.45 ng m -3 ) and summer (1.43 ± 0.46 ng m -3 ). Long-range atmospheric transport dominated by monsoons was a dominant factor influencing the seasonal variations of GEM. The GEM diel trends were related to the wind speed and long-range atmospheric mercury transport. We observed 30 pollution episodes throughout the monitoring period. The analysis of wind direction and backward trajectory suggested that elevated GEM concentrations at the monitoring site were primarily related to the outflows of atmospheric Hg from mainland China and the Indochina peninsula. The △GEM/△CO values also suggested that GEM was significantly affected by the long-range transport from the anthropogenic sources and biomass burning in Asia and Indochina peninsula.

Instrumentation for Power System Disturbance Monitoring, Data ...

African Journals Online (AJOL)

In this paper, the level of instrumentation for power system disturbance monitoring, data acquisition and control in Nigerian Electric Power System; National Electric Power Authority (NEPA) is presented. The need for accurate power system disturbance monitoring is highlighted. A feature of an adequate monitoring, data ...

A Continuously Running High-Rate GEM-TPC for P-bar ANDA

Energy Technology Data Exchange (ETDEWEB)

Boehmer, F.V., E-mail: felix.valentin.boehmer@cern.ch [Technische Universitaet Muenchen Physik Department, James-Franck-Strasse, 85748 Garching (Germany); Angerer, H.; Dorheim, S.; Hoeppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Vandenbroucke, M.; Zhang, X. [Technische Universitaet Muenchen Physik Department, James-Franck-Strasse, 85748 Garching (Germany); Berger, M.; Cusanno, F.; Fabbietti, L.; Lalik, R. [Excellence Cluster Universe, Muenchen (Germany); Beck, R.; Kaiser, D.; Lang, M.; Schmitz, R.; Walther, D.; Winnebeck, A. [Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany)

2011-06-15

The P-bar ANDA fixed target experiment planned at FAIR will investigate fundamental questions of non-perturbative QCD. It makes use of a cooled antiproton beam (momentum: 1.5 to 15GeV/c) and will reach luminosities of up to 2.10{sup 32}cm{sup -2}s{sup -1}, yielding a p-bar p-annihilation rate of 2.10{sup 7}s{sup -1}. One option for the central tracker of P-bar ANDA is a cylindrical, ungated, continuously running TPC with GEM-based gas amplification stage.

Development of the Experiment Control System and Performance Study of the Muon Chambers for the LHCb Experiment

CERN Document Server

Antunes Nobrega, R; Penso, G; Pinci, D

2010-01-01

The work of this thesis practically opened three fronts of the LHCb muon system : the development of the control and monitoring system of the readout electronics; the study of noise and threshold of the detector; and the study of the performance of the muon chambers. The LHCb muon readout apparatus is made 1368 Multi-Wire Proportional Chambers (MWPC) and 24 Gas Electron Multiplier (GEM) chambers connected to approximately 7500 16-channel front-end boards, resulting in 120000 output channels. The large-scale of this system naturally led to a complex control and monitoring system made of about 600 microcontrollers which are directly connected to the front-end electronics and handled by six computers. The development of this control system was accomplished within this thesis; the microcontroller’s firmware and the high level software, operating on the six local computers, were implemented. Besides configuring and monitoring the on-chamber readout electronics, a set of calibration and debugging oriented procedu...

A unique radiation area monitoring system

International Nuclear Information System (INIS)

Murphy, P.C.; Allen, G.C.

1978-01-01

The Remote Area Monitoring Systems (RAMS) monitors four radiation areas with two independent systems in each area. Each system consists of power supplies, four ionization chambers, and four analog and digital circuits. The first system controls the warning beacons, horns, annunciation panel and interlocks. The second system presents a quantitative dose rate indication at the console and in the radiation area

Morbidity Profile of Child Labor at Gem Polishing Units of Jaipur, India

Directory of Open Access Journals (Sweden)

RR Tiwari

2014-07-01

Full Text Available Background: There are millions of working children worldwide. Several causes are suggested for this social evil of which poverty plays a significant role in whether a child will work. Objective: To determine the morbidity profile in the working children of gem polishing units of Jaipur, India and assess some of its associated socio-economic factors. Methods: The present cross-sectional study included 586 gem polishing working children. Using interview, the demographic characteristics, occupational and clinical history of participants were recorded. The reason for taking up the job, income from the job and their desire to attend the school were also asked to assess the social causes of child labor in this region. Results: The mean±SD age of the working children was 11.3±5.3 years. In most of the instances, parents compelled the child to take up the job. Supposed to increase the family income substantially, the child labor activity failed to do so. On the other hand, the children suffered from several occupational health problems like eyestrain, headache, gastrointestinal complaints (eg, abdominal pain, nausea, vomiting, and diarrhea, musculoskeletal symptoms (eg, back pain, pain in limbs, neck pain, and joint pains and skin diseases (eg, scabies, dermatitis. Conclusion: It seems that the social factors forcing the children to work in the studied region, result in deterioration of their health and affect their growth.

Remote Arrhythmia Monitoring System Developed

Science.gov (United States)

York, David W.; Mackin, Michael A.; Liszka, Kathy J.; Lichter, Michael J.

2004-01-01

Telemedicine is taking a step forward with the efforts of team members from the NASA Glenn Research Center, the MetroHealth campus of Case Western University, and the University of Akron. The Arrhythmia Monitoring System is a completed, working test bed developed at Glenn that collects real-time electrocardiogram (ECG) signals from a mobile or homebound patient, combines these signals with global positioning system (GPS) location data, and transmits them to a remote station for display and monitoring. Approximately 300,000 Americans die every year from sudden heart attacks, which are arrhythmia cases. However, not all patients identified at risk for arrhythmias can be monitored continuously because of technological and economical limitations. Such patients, who are at moderate risk of arrhythmias, would benefit from technology that would permit long-term continuous monitoring of electrical cardiac rhythms outside the hospital environment. Embedded Web Technology developed at Glenn to remotely command and collect data from embedded systems using Web technology is the catalyst for this new telemetry system (ref. 1). In the end-to-end system architecture, ECG signals are collected from a patient using an event recorder and are transmitted to a handheld personal digital assistant (PDA) using Bluetooth, a short-range wireless technology. The PDA concurrently tracks the patient's location via a connection to a GPS receiver. A long distance link is established via a standard Internet connection over a 2.5-generation Global System for Mobile Communications/General Packet Radio Service (GSM/GPRS)1 cellular, wireless infrastructure. Then, the digital signal is transmitted to a call center for monitoring by medical professionals.

Fuel combustion, air pollution exposure, and health: The situation in developing countries

International Nuclear Information System (INIS)

Smith, K.R.

1993-01-01

There are a number of recent studies of air pollution in developing-country cities, each of necessity relying heavily on the one available source of comparative international ambient monitoring data, Global Environment Monitoring System (GEMS). In this review, therefore, rather than simply reproduce the GEMS data. The author chose to examine developing-country air pollution from the standpoint of a useful analysis technique that has been under development in recent years: Basically the review is composed of four parts: (1) a brief description of the historical and current relationship between energy use and air pollution; (2) an explanation of the idea of exposure assessment and the power that it can bring to analyses of the health impacts of air pollution; (3) focusing on developing countries, a global exposure assessment, combining demographic data with GEMS outdoor data and less-developed country (LDC) indoor air-monitoring studies; (4) a review of the health effects literature relevant to the micro-environments found to harbor the largest human exposures. 104 refs

Microgravity effects on water supply and substrate properties in porous matrix root support systems

Science.gov (United States)

Bingham, G. E.; Jones, S. B.; Or, D.; Podolski, I. G.; Levinskikh, M. A.; Sytchov, V. N.; Ivanova, T.; Kostov, P.; Sapunova, S.; Dandolov, I.;

Drinking-water monitoring systems

International Nuclear Information System (INIS)

1994-01-01

A new measuring system was developed by the Austrian Research Centre Seibersdorf for monitoring the quality of drinking-water. It is based on the experience made with the installation of UWEDAT (registered trademark) environmental monitoring networks in several Austrian provinces and regions. The standard version of the drinking-water monitoring system comprises sensors for measuring chemical parameters in water, radioactivity in water and air, and meteorological values of the environment. Further measuring gauges, e.g. for air pollutants, can be connected at any time, according to customers' requirements. For integration into regional and supraregional networks, station computers take over the following tasks: Collection of data and status signals transmitted by the subsystem, object protection, intermediate storage and communication of data to the host or several subcentres via Datex-P postal service, permanent lines or radiotransmission

Surveillance systems (PWR) - loose parts monitoring - vibration monitoring - leakage detection

International Nuclear Information System (INIS)

Schuette, A.; Blaesig, H.

1982-01-01

The contribution is engaged in the task and the results of the loose parts monitoring and the vibration monitoring following from the practice at the PWR of Biblis. First a description of both systems - location and type of the sensors used, the treatment of the measurements and the indications - is given. The results of the analysis of some events picked up by the surveillance systems are presented showing applicabilty and benefit of such systems. (orig.)

Chloride ion-catalyzed generation of difluorocarbene for efficient preparation of gem-difluorinated cyclopropenes and cyclopropanes

KAUST Repository

Wang, Fei; Zhang, Wei; Zhu, Jieming; Li, Huaifeng; Huang, Kuo-Wei; Hu, Jinbo

2011-01-01

A chloride ion-catalyzed generation of difluorocarbene from a relatively non-toxic and inexpensive precursor, Me3SiCF2Cl (1), under mild and neutral conditions leads to an efficient preparation of gem-difluorocyclopropenes and difluorocyclopropanes through [2 + 1] cycloaddition reactions with alkynes and alkenes, respectively. © 2011 The Royal Society of Chemistry.

Characterization of a glass GEM for sealed detectors application and reduction of charging-up effects

CERN Document Server

Erdal, Eran

2014-01-01

Apart from high energy physics experiments, there has been a great effort in recent years to incorporate MPGDs in many other applications i.e. medical treatments and imaging and home land security. However, MPGDs (as most gaseous detectors) are normally operated under a constant flushing of the gas. Their use thus turns them expensive since they rely on a constant gas supply and a suitable infrastructure, but most important is the loss of their portability. These reasons have pushed the community to search for other solutions, aiming for the development of sealed detectors. The demands for such is to be made out of low outgassing rate materials and possibly the use of only noble gas to avoid aging due to chemical activity of the ionized gas of the avalanche. The default material for GEM detectors - Polyimide (Kapton), is not suitable for a sealed detector because of its high outgassing rate, thus calling for new solutions. Moreover, GEMs, being essentially made out of an insulating material, pose a problem in...

Car monitoring information systems

Directory of Open Access Journals (Sweden)

Alica KALAŠOVÁ

2008-01-01

Full Text Available The objective of this contribution is to characterize alternatives of information systems used for managing, processing and evaluation of information related to company vehicles. Especially we focus on logging, transferring and processing of on-road vehicle movement information in inland and international transportation. This segment of company information system has to monitor the car movement – actively or passively – according to demand of the company and after the processing it has to evaluate and give the complex monitoring of a situation of all the company vehicles to the controller.

Use of quantitative molecular diagnostic methods to identify causes of diarrhoea in children: a reanalysis of the GEMS case-control study.

Science.gov (United States)

Liu, Jie; Platts-Mills, James A; Juma, Jane; Kabir, Furqan; Nkeze, Joseph; Okoi, Catherine; Operario, Darwin J; Uddin, Jashim; Ahmed, Shahnawaz; Alonso, Pedro L; Antonio, Martin; Becker, Stephen M; Blackwelder, William C; Breiman, Robert F; Faruque, Abu S G; Fields, Barry; Gratz, Jean; Haque, Rashidul; Hossain, Anowar; Hossain, M Jahangir; Jarju, Sheikh; Qamar, Farah; Iqbal, Najeeha Talat; Kwambana, Brenda; Mandomando, Inacio; McMurry, Timothy L; Ochieng, Caroline; Ochieng, John B; Ochieng, Melvin; Onyango, Clayton; Panchalingam, Sandra; Kalam, Adil; Aziz, Fatima; Qureshi, Shahida; Ramamurthy, Thandavarayan; Roberts, James H; Saha, Debasish; Sow, Samba O; Stroup, Suzanne E; Sur, Dipika; Tamboura, Boubou; Taniuchi, Mami; Tennant, Sharon M; Toema, Deanna; Wu, Yukun; Zaidi, Anita; Nataro, James P; Kotloff, Karen L; Levine, Myron M; Houpt, Eric R

2016-09-24

Diarrhoea is the second leading cause of mortality in children worldwide, but establishing the cause can be complicated by diverse diagnostic approaches and varying test characteristics. We used quantitative molecular diagnostic methods to reassess causes of diarrhoea in the Global Enteric Multicenter Study (GEMS). GEMS was a study of moderate to severe diarrhoea in children younger than 5 years in Africa and Asia. We used quantitative real-time PCR (qPCR) to test for 32 enteropathogens in stool samples from cases and matched asymptomatic controls from GEMS, and compared pathogen-specific attributable incidences with those found with the original GEMS microbiological methods, including culture, EIA, and reverse-transcriptase PCR. We calculated revised pathogen-specific burdens of disease and assessed causes in individual children. We analysed 5304 sample pairs. For most pathogens, incidence was greater with qPCR than with the original methods, particularly for adenovirus 40/41 (around five times), Shigella spp or enteroinvasive Escherichia coli (EIEC) and Campylobactor jejuni o C coli (around two times), and heat-stable enterotoxin-producing E coli ([ST-ETEC] around 1·5 times). The six most attributable pathogens became, in descending order, Shigella spp, rotavirus, adenovirus 40/41, ST-ETEC, Cryptosporidium spp, and Campylobacter spp. Pathogen-attributable diarrhoeal burden was 89·3% (95% CI 83·2-96·0) at the population level, compared with 51·5% (48·0-55·0) in the original GEMS analysis. The top six pathogens accounted for 77·8% (74·6-80·9) of all attributable diarrhoea. With use of model-derived quantitative cutoffs to assess individual diarrhoeal cases, 2254 (42·5%) of 5304 cases had one diarrhoea-associated pathogen detected and 2063 (38·9%) had two or more, with Shigella spp and rotavirus being the pathogens most strongly associated with diarrhoea in children with mixed infections. A quantitative molecular diagnostic approach improved population

Remote container monitoring and surveillance systems

International Nuclear Information System (INIS)

Resnik, W.M.; Kadner, S.P.

1995-01-01

Aquila Technologies Group is developing a monitoring and surveillance system to monitor containers of nuclear materials. The system will both visually and physically monitor the containers. The system is based on the combination of Aquila's Gemini All-Digital Surveillance System and on Aquila's AssetLAN trademark asset tracking technology. This paper discusses the Gemini Digital Surveillance system as well as AssetLAN technology. The Gemini architecture with emphasis on anti-tamper security features is also described. The importance of all-digital surveillance versus other surveillance methods is also discussed. AssetLAN trademark technology is described, emphasizing the ability to continually track containers (as assets) by location utilizing touch memory technology. Touch memory technology provides unique container identification, as well as the ability to store and retrieve digital information on the container. This information may relate to container maintenance, inspection schedules, and other information. Finally, this paper describes the combination of the Gemini system with AssetLAN technology, yielding a self contained, container monitoring and area/container surveillance system. Secure container fixture design considerations are discussed. Basic surveillance review functions are also discussed

Critical function monitoring system algorithm development

International Nuclear Information System (INIS)

Harmon, D.L.

1984-01-01

Accurate critical function status information is a key to operator decision-making during events threatening nuclear power plant safety. The Critical Function Monitoring System provides continuous critical function status monitoring by use of algorithms which mathematically represent the processes by which an operating staff would determine critical function status. This paper discusses in detail the systematic design methodology employed to develop adequate Critical Function Monitoring System algorithms

Centralized environmental radiation monitoring system in JAERI

International Nuclear Information System (INIS)

Katagiri, Hiroshi; Kobayashi, Hideo

1993-03-01

Japan Atomic Energy Research Institute (JAERI) has continued the radiation background survey and environmental radiation monitoring to ensure the safety of the residents around the Institute. For the monitoring of β and γ radiations and α and β radioactivities in air, the centralized automatic environmental radiation monitoring system (EMS) applying a computer with monitoring stations (MS) was established. The system has been renewed twice in 1973 and 1988. In 1962, a new concept emergency environmental γ-ray monitoring system (MP) was begun to construct and completed in 1965 independent of EMS. The first renewal of the EMS was carried out by focusing on the rapid and synthetic judgement and estimation of the environmental impacts caused by radiation and radioactive materials due to the operation of nuclear facilities by centralizing the data measured at MS, MP, a meteorological station, stack monitors and drainage monitoring stations under the control of computer. Present system renewed in 1988 was designed to prevent the interruption of monitoring due to computer troubles, communication troubles and power failures especially an instant voltage drop caused by thunder by reflecting the experiences through the operation and maintenance of the former system. Dual telemeters whose power is constantly supplied via batteries (capable of 10 min. monitoring after power failure) are equipped in the monitoring center to cope with telemeter troubles, which has operated successfully without any suspension being attributable to the power failures and telemeter troubles. (J.P.N.)

Quench and protection characteristics of the GEM test coil

International Nuclear Information System (INIS)

Chaniotakis, E.A.; Marston, P.G.

1994-01-01

The GEM test coil, will be wound from 70 m of conductor identical to that used in the full scale magnet. The coil configuration will duplicate the field distribution of the full scale magnet and current control will duplicate full scale current decay characteristics. Therefore, quench/protection analysis of this coil will reveal very important information about the behavior of the full scale model. Due to the uncertainty associated with the contact between the cable, the conduit and the sheath, a parametric analysis has been performed in order to determine and bracket the behavior. With no electrical contact the quench evolves normally until, due to heat transfer from the sheath into the cable, the superconductor temperature becomes critical and the entire length becomes normal

Alu Mobile Elements: From Junk DNA to Genomic Gems

Directory of Open Access Journals (Sweden)

Sami Dridi

2012-01-01

Full Text Available Alus, the short interspersed repeated sequences (SINEs, are retrotransposons that litter the human genomes and have long been considered junk DNA. However, recent findings that these mobile elements are transcribed, both as distinct RNA polymerase III transcripts and as a part of RNA polymerase II transcripts, suggest biological functions and refute the notion that Alus are biologically unimportant. Indeed, Alu RNAs have been shown to control mRNA processing at several levels, to have complex regulatory functions such as transcriptional repression and modulating alternative splicing and to cause a host of human genetic diseases. Alu RNAs embedded in Pol II transcripts can promote evolution and proteome diversity, which further indicates that these mobile retroelements are in fact genomic gems rather than genomic junks.

Distributed intelligent urban environment monitoring system

Science.gov (United States)

Du, Jinsong; Wang, Wei; Gao, Jie; Cong, Rigang

2018-02-01

The current environmental pollution and destruction have developed into a world-wide major social problem that threatens human survival and development. Environmental monitoring is the prerequisite and basis of environmental governance, but overall, the current environmental monitoring system is facing a series of problems. Based on the electrochemical sensor, this paper designs a small, low-cost, easy to layout urban environmental quality monitoring terminal, and multi-terminal constitutes a distributed network. The system has been small-scale demonstration applications and has confirmed that the system is suitable for large-scale promotion