Irradiation chamber for photoactivation patient treatment system

International Nuclear Information System (INIS)

Lee, K.H.; Troutner, V.H.; Goss, J.; King, M.J.

1988-01-01

A flat plate irradiation chamber is described for use in a patient treatment system for altering cells, including treating the cells with a photoactivatable agent and passing the cells and the agent through a field of photoactivating radiation whereby the agent is caused to be activated and to affect the cells. The agent and the cells are contained in the irradiation chamber during irradiation. The flat plate irradiation chamber comprises: a rigid top sheet matably joined with a rigid bottom sheet, forming therebetween a rigid serpentine pathway for conducting the cells through the field of radiation; and pump block means for holding tubing means in fluid communication with the serpentine pathway and adapted for engaging a peristaltic pump whereby rotation of the pump causes the cells to flow through the serpentine pathway, and wherein the chamber is removable from the system and disposable

A First-Level Muon Trigger Based on the ATLAS Muon Drift Tube Chambers With High Momentum Resolution for LHC Phase II

CERN Document Server

Richter, R; The ATLAS collaboration; Ott, S; Kortner, O; Fras, M; Gabrielyan, V; Danielyan, V; Fink, D; Nowak, S; Schwegler, P; Abovyan, S

2014-01-01

The Level-1 (L1) trigger for muons with high transverse momentum (pT) in ATLAS is based on chambers with excellent time resolution, able to identify muons coming from a particular beam crossing. These trigger chambers also provide a fast pT-measurement of the muons, the accuracy of the measurement being limited by the moderate spatial resolution of the chambers along the deflecting direction of the magnetic field (eta-coordinate). The higher luminosity foreseen for Phase-II puts stringent limits on the L1 trigger rates, and a way to control these rates would be to improve the spatial resolution of the triggering system, drastically sharpening the turn-on curve of the L1 trigger. To do this, the precision tracking chambers (MDT) can be used in the L1 trigger, provided the corresponding trigger latency is increased as foreseen. The trigger rate reduction is accomplished by strongly decreasing the rate of triggers from muons with pT lower than a predefined threshold (typically 20 GeV), which would otherwise trig...

Improved Rhenium Thrust Chambers for In-Space Propulsion, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Radiation-cooled, bipropellant thrust chambers are being considered for the ascent/descent engines and reaction control systems for NASA missions such as Mars Sample...

Novel Left Ventricular Assist Systems® I and II for Cardiac Recovery: The Driver

OpenAIRE

Cervino, Claudio; Nasini, Victor; Sroka, Agnieszka; Diluch, Armando; Cáceres, Miguel; Sellanes, Miguel; Malusardi, Adriano; del Rio, Miguel; Pham, Si M.; Liotta, Domingo

2005-01-01

We have recently described the Novel Left Ventricular Assist Systems® (Novel LVAS®) I and II, which avoid cannulation of cardiac chambers and synchronize pumping with the patient's electrocardiogram.

Chamber transport for heavy ion fusion

International Nuclear Information System (INIS)

Olson, Craig L.

2014-01-01

A brief review is given of research on chamber transport for HIF (heavy ion fusion) dating from the first HIF Workshop in 1976 to the present. Chamber transport modes are categorized into ballistic transport modes and channel-like modes. Four major HIF reactor studies are summarized (HIBALL-II, HYLIFE-II, Prometheus-H, OSIRIS), with emphasis on the chamber transport environment. In general, many beams are used to provide the required symmetry and to permit focusing to the required small spots. Target parameters are then discussed, with a summary of the individual heavy ion beam parameters required for HIF. The beam parameters are then classified as to their line charge density and perveance, with special emphasis on the perveance limits for radial space charge spreading, for the space charge limiting current, and for the magnetic (Alfven) limiting current. The major experiments on ballistic transport (SFFE, Sabre beamlets, GAMBLE II, NTX, NDCX) are summarized, with specific reference to the axial electron trapping limit for charge neutralization. The major experiments on channel-like transport (GAMBLE II channel, GAMBLE II self-pinch, LBNL channels, GSI channels) are discussed. The status of current research on HIF chamber transport is summarized, and the value of future NDCX-II transport experiments for the future of HIF is noted

The drift chamber system of the MEG experiment

Energy Technology Data Exchange (ETDEWEB)

Hildebrandt, Malte, E-mail: malte.hildebrandt@psi.c [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

2010-11-01

The MEG experiment searches for the lepton flavour violating decay {mu}{yields}e{gamma} and is aiming for a sensitivity of 10{sup -13} in the branching ratio in order to probe new physics beyond the standard model. The experiment is located at the Paul Scherrer Institut (PSI) in Switzerland, where one of the world's most intensive surface muon beams is located. Physics data taking started in September 2008. The drift chamber system is part of the innovative positron spectrometer of the MEG experiment and consists of 16 drift chamber modules. The system is designed to ensure precision measurement of 52.8 MeV/c positrons. Design, construction, geometrical alignment and performance of the drift chamber system are presented.

System of multiwire proportional chambers at the separated particle channel for the Mirabelle bubble chamber

International Nuclear Information System (INIS)

Bryukhanov, N.S.; Galyaev, N.A.; Kotov, V.I.; Prosin, B.V.; Romanov, Yu.A.; Khodyrev, Yu.S.

1980-01-01

A system of multiwire proportional chambers (MPC) operating on-line with a M-6000 computer used during tuning and monitoring of beam parameters in a separated particle channel for the Mirabelle bubble chamber is described. Peculiarities of the construction and main characteristics of two MPC versions are considered. The first version is intended for placing in a vacuum at the edges of high-frequency separator deflector, the second one - for placing outside a vacuum in ionoguide gaps. Power supply of the proportional chambers is carried out from local compact (160x95x50 mm) high-voltage sources remotely controlled from a channel panel by low voltage. A MPC position diagram in the accelerator channel, flowsheet of registering electronics for the MPC system, main circuits of high-voltage power source, analog-to-digital converter of a code and trunk amplifier are given. A graph of amplifier signal amplitude dependence on high voltage of a chamber for a different composition of a gaseous mixture is presented. It is noted that the used elements of the electronic system provide the reliable processing of data and its transmission for a great distance (approximately 400 m). It is underlined that the MPC system operation for a long time has shown its high efficiency and reliability

A plant chamber system with downstream reaction chamber to study the effects of pollution on biogenic emissions

NARCIS (Netherlands)

Timovsky, J.; Gankema, Paulien; Pierik, Ronald; Holzinger, Rupert

2014-01-01

A system of two plant chambers and a downstream reaction chamber has been set up to investigate the emission of biogenic volatile organic compounds (BVOCs) and possible effects of pollutants such as ozone. The system can be used to compare BVOC emissions from two sets of differently treated plants,

Secondary Electron Yield Measurements and Groove Chambers Tests in the PEP-II Beam Line Straights Sections

International Nuclear Information System (INIS)

Pivi, M

2008-01-01

Beam instability caused by the electron cloud has been observed in positron and proton storage rings and it is expected to be a limiting factor in the performance of the positron Damping Ring (DR) of future Linear Colliders such as ILC and CLIC [1, 2]. In the Positron Low Energy Ring (LER) of the PEP-II accelerator, we have installed vacuum chambers with rectangular grooves in a straight magnetic-free section to test this promising possible electron cloud mitigation technique. We have also installed a special chamber to monitor the secondary electron yield of TiN and TiZrV (NEG) coating, Copper, Stainless Steel and Aluminum under the effect of electron and photon conditioning in situ in the beam line. In this paper, we describe the ongoing R and D effort to mitigate the electron cloud effect for the ILC damping ring, the latest results on in situ secondary electron yield conditioning and recent update on the groove tests in PEP-II

Drift chamber readout system of the DIRAC experiment

CERN Document Server

Afanasiev, L G

2002-01-01

A drift chamber readout system of the DIRAC experiment at CERN is presented. The system is intended to read out the signals from planar chambers operating in a high current mode. The sense wire signals are digitized in the 16-channel time-to-digital converter boards which are plugged in the signal plane connectors. This design results in a reduced number of modules, a small number of cables and high noise immunity. The system has been successfully operating in the experiment since 1999.

Inertial confinement fusion reaction chamber and power conversion system study

International Nuclear Information System (INIS)

Maya, I.; Schultz, K.R.; Battaglia, J.M.

1984-09-01

GA Technologies has developed a conceptual ICF reactor system based on the Cascade rotating-bed reaction chamber concept. Unique features of the system design include the use of low activation SiC in a reaction chamber constructed of box-shaped tiles held together in compression by prestressing tendons to the vacuum chamber. Circulating Li 2 O granules serve as the tritium breeding and energy transport material, cascading down the sides of the reaction chamber to the power conversion system. The total tritium inventory of the system is 6 kg; tritium recovery is accomplished directly from the granules via the vacuum system. A system for centrifugal throw transport of the hot Li 2 O granules from the reaction chamber to the power conversion system has been developed. A number of issues were evaluated during the course of this study. These include the response of first-layer granules to the intense microexplosion surface heat flux, cost effective fabrication of Li 2 O granules, tritium inventory and recovery issues, the thermodynamics of solids-flow options, vacuum versus helium-medium heat transfer, and the tradeoffs of capital cost versus efficiency for alternate heat exchange and power conversion system option. The resultant design options appear to be economically competitive, safe, and environmentally attractive

On-chamber readout system for the ATLAS MDT Muon Spectrometer

CERN Document Server

Chapman, J; Ball, R; Brandenburg, G; Hazen, E; Oliver, J; Posch, C

2004-01-01

The ATLAS MDT Muon Spectrometer is a system of approximately 380,000 pressurized cylindrical drift tubes of 3 cm diameter and up to 6 meters in length. These Monitored Drift Tubes (MDTs) are precision- glued to form super-layers, which in turn are assembled into precision chambers of up to 432 tubes each. Each chamber is equipped with a set of mezzanine cards containing analog and digital readout circuitry sufficient to read out 24 MDTs per card. Up to 18 of these cards are connected to an on-chamber DAQ element referred to as a Chamber Service Module, or CSM. The CSM multiplexes data from the mezzanine cards and outputs this data on an optical fiber which is received by the off-chamber DAQ system. Thus, the chamber forms a highly self-contained unit with DC power in and a single optical fiber out. The Monitored Drift Tubes, due to their length, require a terminating resistor at their far end to prevent reflections. The readout system has been designed so that thermal noise from this resistor remains the domi...

Technology, Applications, and Process Challenges of Dual Chamber Systems.

Science.gov (United States)

Werk, Tobias; Ludwig, Imke S; Luemkemann, Joerg; Mahler, Hanns-Christian; Huwyler, Joerg; Hafner, Mathias

2016-01-01

Dual-chamber systems provide an option as a drug and device combination product, when home care and emergency lyophilized products are intended. Nevertheless, until today, there are only a few products on the market, due to the challenges and limitations in manufacturability, product formulation, and product stability in a dual-chamber configuration, as well as economic considerations. This review serves to describe currently available dual-chamber systems and to discuss factors to be considered for appropriate selection and establishing fill-finish processes. Copyright © 2016. Published by Elsevier Inc.

Establishment of a tandem ionization chamber system in standard mammography beams

International Nuclear Information System (INIS)

Silva, Jonas O. da; Caldas, L.V.E.

2011-01-01

A double-faced tandem ionization chamber system was developed at the Calibration Laboratory of IPEN. It has different collecting electrode materials: aluminium and graphite. The response repeatability and reproducibility and the energy dependence test of this tandem ionization chamber were evaluated. The chamber response stability is within the ±3% limit recommended in international standards. The energy dependence test of the ionization chamber system using the tandem curve obtained, presented agreement with literature results. (author)

Atmospheric scanning electron microscope system with an open sample chamber: Configuration and applications

Energy Technology Data Exchange (ETDEWEB)

Nishiyama, Hidetoshi, E-mail: hinishiy@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Koizumi, Mitsuru, E-mail: koizumi@jeol.co.jp [JEOL Technics Ltd., 2-6-38 Musashino, Akishima, Tokyo 196-0021 (Japan); Ogawa, Koji, E-mail: kogawa@jeol.co.jp [JEOL Technics Ltd., 2-6-38 Musashino, Akishima, Tokyo 196-0021 (Japan); Kitamura, Shinich, E-mail: kitamura@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Konyuba, Yuji, E-mail: ykonyuub@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Watanabe, Yoshiyuki, E-mail: watanabeyoshiy@pref.yamagata.jp [Yamagata Research Institute of Technology, 2-2-1, Matsuei, Yamagata 990-2473 (Japan); Ohbayashi, Norihiko, E-mail: n.ohbayashi@m.tohoku.ac.jp [Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Fukuda, Mitsunori, E-mail: nori@m.tohoku.ac.jp [Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Suga, Mitsuo, E-mail: msuga@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Sato, Chikara, E-mail: ti-sato@aist.go.jp [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-4, Umezono, Tsukuba 305-8568 (Japan)

2014-12-15

An atmospheric scanning electron microscope (ASEM) with an open sample chamber and optical microscope (OM) is described and recent developments are reported. In this ClairScope system, the base of the open sample dish is sealed to the top of the inverted SEM column, allowing the liquid-immersed sample to be observed by OM from above and by SEM from below. The optical axes of the two microscopes are aligned, ensuring that the same sample areas are imaged to realize quasi-simultaneous correlative microscopy in solution. For example, the cathodoluminescence of ZnO particles was directly demonstrated. The improved system has (i) a fully motorized sample stage, (ii) a column protection system in the case of accidental window breakage, and (iii) an OM/SEM operation system controlled by a graphical user interface. The open sample chamber allows the external administration of reagents during sample observation. We monitored the influence of added NaCl on the random motion of silica particles in liquid. Further, using fluorescence as a transfection marker, the effect of small interfering RNA-mediated knockdown of endogenous Varp on Tyrp1 trafficking in melanocytes was examined. A temperature-regulated titanium ASEM dish allowed the dynamic observation of colloidal silver nanoparticles as they were heated to 240 °C and sintered. - Highlights: • Atmospheric SEM (ASEM) allows observation of samples in liquid or gas. • Open sample chamber allows in situ monitoring of evaporation and sintering processes. • in situ monitoring of processes during reagent administration is also accomplished. • Protection system for film breakage is developed for ASEM. • Usability of ASEM has been improved significantly including GUI control.

Atmospheric scanning electron microscope system with an open sample chamber: Configuration and applications

International Nuclear Information System (INIS)

Nishiyama, Hidetoshi; Koizumi, Mitsuru; Ogawa, Koji; Kitamura, Shinich; Konyuba, Yuji; Watanabe, Yoshiyuki; Ohbayashi, Norihiko; Fukuda, Mitsunori; Suga, Mitsuo; Sato, Chikara

2014-01-01

An atmospheric scanning electron microscope (ASEM) with an open sample chamber and optical microscope (OM) is described and recent developments are reported. In this ClairScope system, the base of the open sample dish is sealed to the top of the inverted SEM column, allowing the liquid-immersed sample to be observed by OM from above and by SEM from below. The optical axes of the two microscopes are aligned, ensuring that the same sample areas are imaged to realize quasi-simultaneous correlative microscopy in solution. For example, the cathodoluminescence of ZnO particles was directly demonstrated. The improved system has (i) a fully motorized sample stage, (ii) a column protection system in the case of accidental window breakage, and (iii) an OM/SEM operation system controlled by a graphical user interface. The open sample chamber allows the external administration of reagents during sample observation. We monitored the influence of added NaCl on the random motion of silica particles in liquid. Further, using fluorescence as a transfection marker, the effect of small interfering RNA-mediated knockdown of endogenous Varp on Tyrp1 trafficking in melanocytes was examined. A temperature-regulated titanium ASEM dish allowed the dynamic observation of colloidal silver nanoparticles as they were heated to 240 °C and sintered. - Highlights: • Atmospheric SEM (ASEM) allows observation of samples in liquid or gas. • Open sample chamber allows in situ monitoring of evaporation and sintering processes. • in situ monitoring of processes during reagent administration is also accomplished. • Protection system for film breakage is developed for ASEM. • Usability of ASEM has been improved significantly including GUI control

System of two-coordinate cylindrical proportional chambers with resistive cathode

International Nuclear Information System (INIS)

Golubev, V.B.; Peryshkin, A.N.; Red'ko, I.Yu.; Serednyakov, S.I.

1981-01-01

A system of two-coordinate cylindrical proportional chambers is developed for experiments on studying the e + e - annihilation. The system consists of 6 independent proportional chambers of semicylindrical configuration with a gap between anode and cathode equal to 5 mm. The diameter of an external chnsamber equals 25 cm and its length cotitutes 40 cm. Anode wires 20 μm in-diameter are fixed in parallel to the system axis with a pitch of 2-3 mm. The use of a resisti ve cothode permitting to maintain the anode wires and delay circuits under the ground potential is one of the specific feabures of the given chamber. The resistive layer is produced by sputtering the aquadag aqueous suspension with the polyvinylacetate emulsion on a fibregrass-textolite. 8 delay circuits is mounted outside of each chamber from the side of the cathode. A functional flowsheet of a data readout system is given. The track angte is determined directiy according to the numbers of operated wires; coordinates along the axis are determined by means of the delay circuits placed outside the chamber near the resistive cathode. The accuracy of the coordinate measurement in both directions constitutes about 1 mm. Each chamber permits to measure the coordinates of several particles, if they entry into different delay circuits. The proportional chambers are filled with the mixture of Ar+30%CO 2 . Anode and cathode efficiencies in the plateau region (150-250) exceed 99%

Development of pattern recognition algorithms for the central drift chamber of the Belle II detector

Energy Technology Data Exchange (ETDEWEB)

Trusov, Viktor

2016-11-04

In this thesis, the development of one of the pattern recognition algorithms for the Belle II experiment based on conformal and Legendre transformations is presented. In order to optimize the performance of the algorithm (CPU time and efficiency) specialized processing steps have been introduced. To show achieved results, Monte-Carlo based efficiency measurements of the tracking algorithms in the Central Drift Chamber (CDC) has been done.

Automatic control system for measuring currents produced by ionization chambers

International Nuclear Information System (INIS)

Brancaccio, Franco

2002-01-01

Ionization Chambers in current mode operation are usually used in Nuclear Metrology. Activity measurements are quickly performed by Ionization Chambers, with very good precision. For this purpose measurements of very low ionization currents, carried out by high quality instrumentation, are required. Usually, electrometers perform the current integration method under command of signals from an automation system, in order to reduce the measurement uncertainties. Among the measurement systems at the Laboratorio de Metrologia Nuclear (LMN) of IPEN, there are two ionization chamber systems. In the present work, an automation system developed for current integration measurements is described. This automation system is composed by software (graphic interface and control) and an electronic module connected to a microcomputer, by means of a commercial data acquisition card. Several test measurements were performed in order to determine the intrinsic uncertainty, linearity and stability of the system. Using calibrated radioactive solutions, the IG12/A20 chamber calibration factors for 18 F and 153 Sm were obtained, making possible to determine activities of these radionuclides. (author)

Tuning of the cosmic-ray test system of the BESIII drift chamber

International Nuclear Information System (INIS)

Wu Zhi; Liu Jianbei; Qin Zhonghua; Wu Linghui; Chen Chang; Chen Yuanbo; Chen Mali; Chen Xihui; Dong Mingyi; Guan Beiju; Huang Jie; Jiang Xiaoshan; Jin Yan; Li Fei; Li Renying; Li Xiaonan; Lei Guangkun; Liu Rongguang; Luo Xiaolan; Ma Xiaoyan; Sheng Huayi; Sun Hansheng; Tang Xiao; Wang Lan; Wang Liang; Xu Meihang; Zhang Jian; Zhang Hongyu; Zhang Yinhong; Zhao Yubin; Zhao Pingping; Zhu Kejun; Zhu Qiming; Zhuang Bao'an

2010-01-01

The BESIII drift chamber and its subsystems need a cosmic-ray test after the chamber construction to check the chamber construction quality, testing the joint operation of the whole system and the performance of the chamber. The noise performance, drift time and charge measurements, and the scanning of channels were examined specifically. The preliminary results of the test indicate that the whole system works well. (authors)

Construction of the Cleo III drift chamber

International Nuclear Information System (INIS)

Csorna, S.; Marka, S.; Dickson, M.; Dombrowski, S. von; Peterson, D.; Thies, P.; Glenn, S.; Thorndike, E.H.; Kravchenko, I.

1998-01-01

The CLEO III group is constructing a new chamber to be installed as part of the staged luminosity upgrade program at the Cornell electron storage ring and compatible with the interaction region optics. Although having less radial extent than the current CLEO II tracking system, CLEO III will have equivalent momentum resolution because of material reduction in the drift chamber inner skin and gas. The thin inner skin requires special attention to the end-plate motion due to wire creep. During stringing, use of a robot will fully automate the wire handling on the upper end. (author)

Calibration of the beam-position monitor system for the SLAC PEP-II B factory

International Nuclear Information System (INIS)

Johnson, R.; Smith, S.; Kurita, N.

1997-06-01

The Beam-Position Monitors (BPM) for the PEP-II B Factory consist of four 1.5-cm diameter button style pickups mounted on the diagonals of the quadrupole vacuum chambers. Before installation of the vacuum chambers in the quadrupole assemblies, the electrical center of the BPMs is measured with respect to the mechanical center in a calibration test stand. In this paper the calibration test stand is described and the precision and accuracy of the calibrations are presented. After installation of the quadrupole assemblies in the PEP-II tunnel, the passive attenuation for each channel of the system is measured to preserve the accuracy of the calibration. Finally, the active electronics includes an onboard calibrator. Results for these portions of the calibration are presented

Sag compensation system for assembly of MDT-chambers for the ATLAS experiment

International Nuclear Information System (INIS)

Barashkov, A.V.; Glonti, G.L.; Gongadze, A.L.; Evtukhovich, P.G.; Il'yushenko, E.N.; Kotov, S.A.; Kruchonok, V.G.; Tskhadadze, Eh.G.; Chepurnov, V.F.; Shelkov, G.A.

2005-01-01

The description of a system of the devices created for compensation of the gravitational deflection of the drift chamber during its assembly is presented. By means of this system during stage-by-stage gluing of layers of tube drift detectors to the chamber the transversal deflection considerably decreases and by that high accuracy of mutual position of separate tubes is provided. The devices were applied at assembly of 74 MDT-chambers of the ATLAS experiment. Design values of deformation of the chambers as well as the results of measurement of transversal deflections obtained during the assembly with the use of the system of sag compensation are given. Testing of chambers on the X-ray tomograph at CERN has shown that the accuracy of the positions of separate signal wires inside the assembled chambers is within the limits of the required 20 μm

Development of standard ionization chamber counting system for activity measurements

International Nuclear Information System (INIS)

Pyun, Woong Beom; Lee, Hyun Koo; Lee, Hai Yong; Park, Tae Soon

1998-01-01

This study is to set up the activity measuring system using a 4π γ ionization chamber as used mainly in national standards laboratories that are responsible for radionuclide metrology. The software for automatic control between the electrometer and personal computer is developed using Microsoft visual basic 4.0 and IEEE488 Interface. The reproducibility of this 4π γ ionization chamber is about 0.02% and the background current is 0.054±0.024 pA. this 4π γ ionization chamber is calibrated by 6 standard gamma emitting radionuclides from KRISS. According to the result of this study, it is revealed that this 4π γ ionization chamber counting system can be used as a secondary standard instrument for radioactivity measurement

Development of standard ionization chamber counting system for activity measurements

CERN Document Server

Pyun, W B; Lee, H Y; Park, T S

1998-01-01

This study is to set up the activity measuring system using a 4 pi gamma ionization chamber as used mainly in national standards laboratories that are responsible for radionuclide metrology. The software for automatic control between the electrometer and personal computer is developed using Microsoft visual basic 4.0 and IEEE488 Interface. The reproducibility of this 4 pi gamma ionization chamber is about 0.02% and the background current is 0.054+-0.024 pA. this 4 pi gamma ionization chamber is calibrated by 6 standard gamma emitting radionuclides from KRISS. According to the result of this study, it is revealed that this 4 pi gamma ionization chamber counting system can be used as a secondary standard instrument for radioactivity measurement.

Drift chamber vertex detectors for SLC/LEP

Energy Technology Data Exchange (ETDEWEB)

Hayes, K G

1988-03-01

Factors influencing the design of drift chamber vertex detectors for SLC and LEP are discussed including global strategy, chamber gas, cell design, and signal processing. The designs of the vertex chambers for the L3 and OPAL experiments at LEP and the Mark II experiment at the SLC are described.

RF HEATING AND TEMPERATURE OSCILLATIONS DUE TO A SMALL GAP IN A PEP-II VACUUM CHAMBER

International Nuclear Information System (INIS)

Novokhatski, Alexander

2003-01-01

Wake fields excited in a small gap of a vacuum chamber by ampere beams can have enough amplitude to heat the chamber. The electric component of these fields can be above the arcing limit. Usually flange connections in a vacuum chamber contain a vacuum gasket and an inner RF gasket. If a small gap occurs between the RF gasket and flange surface, wake fields can heat the flanges. The flanges are usually made of stainless steel, which efficiently absorbs RF power. Some flanges consist of two parts (like a vacuum valve flange) and are mechanically connected but have poor thermal contact. A temperature rise can lengthen the inner part of the flange and make firmer the thermal contact to the outer part of the flange. The heat will then flow to the outer part of the flange, which is air and water-cooled. This cooling lowers the flange temperature and the thermal contact becomes poor again. This ''quasi'' periodic mechanism can explain the nature of temperature oscillations observed at several locations in PEP-II, the SLAC B-factory

Design and analysis of a wiggler magnet system for the PEP-II B-Factory LER

International Nuclear Information System (INIS)

Heim, J.; Kendall, M.; Bertolini, L.; Fackler, O.; O'Connor, T.; Swan, T.; Zholents, A.

1996-01-01

The Low Energy Ring (LER) of the PEP-II B-Factory will use a wiggler magnet system for emittance control and additional damping. The wiggler magnet system is a set of 11 individual iron core, water cooled, dipole magnets designed to operate at 1.6 T and generate 400 kW of synchrotron radiation. Space has been provided to add a second wiggler with an additional 400 kW of synchrotron radiation if more damping is needed in the future. A copper vacuum chamber is used with continuous antechambers connected to both sides of the beam chamber via slots. Synchrotron radiation dump surfaces and distributed vacuum pumping are located in both antechambers. The authors describe the design and analysis of the wiggler magnets and the salient features of the vacuum chamber and dumps

Remote Control System of the TJ-II Microwave Transmission Lines Mirrors

International Nuclear Information System (INIS)

Lopez Sanchez, A.; Fernandez, A.; Cappa, A.; Gama, J. de la; Olivares, J.; Garcia, R.; Chamorro, M.

2007-01-01

The ECRH system of the TJ-II stellarator has two gyrotrons, which deliver a maximum power of 300 kW each at a frequency of 53.2 GHz. Another 28 GHz gyrotron will be used to heat the plasma by electron Bernstein waves (EBWH). The microwave power is transmitted from the gyrotrons to the vacuum chamber by two quasi-optical transmission lines for ECRH and a corrugated waveguide for EBWH. All transmission lines have an internal movable mirror inside the vacuum chamber to focus the beam and to be able to change the launching angle. The control of the beam polarization is very important and the lines have two corrugated mirrors, which actuate as polarizers. In this report the control system of the position of these three internal mirrors and the polarizers of the EBWH transmission line is described. (Author) 20 refs

The drift velocity monitoring system of the CMS barrel muon chambers

CERN Document Server

Altenhoefer, Georg Friedrich; Heidemann, Carsten Andreas; Reithler, Hans; Sonnenschein, Lars; Teyssier, Daniel Francois

2017-01-01

The drift velocity is a key parameter of drift chambers. Its value depends on several parameters: electric field, pressure, temperature, gas mixture, and contamination, for example, by ambient air. A dedicated Velocity Drift Chamber (VDC) with 1-L volume has been built at the III. Phys. Institute A, RWTH Aachen, in order to monitor the drift velocity of all CMS barrel muon Drift Tube chambers. A system of six VDCs was installed at CMS and has been running since January 2011. We present the VDC monitoring system, its principle of operation, and measurements performed.

The drift velocity monitoring system of the CMS barrel muon chambers

Science.gov (United States)

Altenhöfer, Georg; Hebbeker, Thomas; Heidemann, Carsten; Reithler, Hans; Sonnenschein, Lars; Teyssier, Daniel

2018-04-01

The drift velocity is a key parameter of drift chambers. Its value depends on several parameters: electric field, pressure, temperature, gas mixture, and contamination, for example, by ambient air. A dedicated Velocity Drift Chamber (VDC) with 1-L volume has been built at the III. Phys. Institute A, RWTH Aachen, in order to monitor the drift velocity of all CMS barrel muon Drift Tube chambers. A system of six VDCs was installed at CMS and has been running since January 2011. We present the VDC monitoring system, its principle of operation, and measurements performed.

Environmental gamma radiation monitoring system with a large volume air ionization chamber

International Nuclear Information System (INIS)

Duftschmid, K.E.; Strachotinsky, C.; Witzani, J.

1986-01-01

An improved environmental monitoring system has been designed and tested consisting of an ionization chamber with 120 l sensitive volume, operated at atmospheric pressure, and a commercial electrometer amplifier with digital voltmeter. The system is controlled by a desk calculator with printer for automated operation and calculation of dose and doserate. The ionization chamber provides superior dosimetric performance as compared to usual GM-counters and high pressure chambers. The system has been field-tested during the 'European Intercomparison Programme for Environmental Monitoring Instruments' organized by the Commission of the European Communities. (Author)

Around the laboratories: Rutherford: Successful tests on bubble chamber target technique; Stanford (SLAC): New storage rings proposal; Berkeley: The HAPPE project to examine cosmic rays with superconducting magnets; The 60th birthday of Professor N.N. Bogolyubov; Argonne: Performance of the automatic film measuring system POLLY II

CERN Multimedia

1969-01-01

Around the laboratories: Rutherford: Successful tests on bubble chamber target technique; Stanford (SLAC): New storage rings proposal; Berkeley: The HAPPE project to examine cosmic rays with superconducting magnets; The 60th birthday of Professor N.N. Bogolyubov; Argonne: Performance of the automatic film measuring system POLLY II

Image digitizer system for bubble chamber laser

International Nuclear Information System (INIS)

Haggerty, H.

1986-01-01

An IBM PC-based image digitizer system has been assembled to monitor the laser flash used for holography at the 15 foot bubble chamber. The hardware and the operating software are outlined. For an operational test of the system, an array of LEDs was flashed with a 10 microsecond pulse and the image was grabbed by one of the operating programs and processed

Thermal System Upgrade of the Space Environment Simulation Test Chamber

Science.gov (United States)

Desai, Ashok B.

1997-01-01

The paper deals with the refurbishing and upgrade of the thermal system for the existing thermal vacuum test facility, the Space Environment Simulator, at NASA's Goddard Space Flight Center. The chamber is the largest such facility at the center. This upgrade is the third phase of the long range upgrade of the chamber that has been underway for last few years. The first phase dealt with its vacuum system, the second phase involved the GHe subsystem. The paper describes the considerations of design philosophy options for the thermal system; approaches taken and methodology applied, in the evaluation of the remaining "life" in the chamber shrouds and related equipment by conducting special tests and studies; feasibility and extent of automation, using computer interfaces and Programmable Logic Controllers in the control system and finally, matching the old components to the new ones into an integrated, highly reliable and cost effective thermal system for the facility. This is a multi-year project just started and the paper deals mainly with the plans and approaches to implement the project successfully within schedule and costs.

The role of Chamber of Commerce System in international economic relations

Directory of Open Access Journals (Sweden)

Diana Ramona Popescu

2016-12-01

Full Text Available The article focuses on the analysis of chambers of commerce and industry, non-governmental organizations, fully committed to stimulating economic initiative and increase business competitiveness. The objective of the paper is to highlight the instruments and means through which the chambers of commerce and industry provide support for the development and promotion of business and their ability to settle trade disputes. In the first part of the article are presented the characteristics and functions of chambers, organizations that support the development of international trade. Although the role of chambers of commerce and industry is essentially the same, they behave national and regional specific features. The second part advance the chamber means for promoting international trade through concrete examples based on analyzing actions of chambers of commerce and industry. The article ends with an assessment of the actual situation of the county chambers of commerce and industry in Romania, obtained after a personal research. The survey is structured around two major themes: chamber system in Romania and the Romanian business environment.

Open loop, auto reversing liquid nitrogen circulation thermal system for thermo vacuum chamber

International Nuclear Information System (INIS)

Naidu, M C A; Nolakha, Dinesh; Saharkar, B S; Kavani, K M; Patel, D R

2012-01-01

In a thermo vacuum chamber, attaining and controlling low and high temperatures (-100 Deg. C to +120 Deg. C) is a very important task. This paper describes the development of 'Open loop, auto reversing liquid nitrogen based thermal system'. System specifications, features, open loop auto reversing system, liquid nitrogen flow paths etc. are discussed in this paper. This thermal system consists of solenoid operated cryogenic valves, double embossed thermal plate (shroud), heating elements, temperature sensors and PLC. Bulky items like blowers, heating chambers, liquid nitrogen injection chambers, huge pipe lines and valves were not used. This entire thermal system is very simple to operate and PLC based, fully auto system with auto tuned to given set temperatures. This system requires a very nominal amount of liquid nitrogen (approx. 80 liters / hour) while conducting thermo vacuum tests. This system was integrated to 1.2m dia thermo vacuum chamber, as a part of its augmentation, to conduct extreme temperature cycling tests on passive antenna reflectors of satellites.

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

International Nuclear Information System (INIS)

Nobrega, Rafael A.; Pinci, Davide

2011-01-01

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

Safety and environmental aspects of HYLIFE-II

International Nuclear Information System (INIS)

Dolan, T.J.; Longhurst, G.R.

1990-01-01

The HYLIFE-II inertial confinement fusion reactor uses a Flibe spray for blast chamber protection and tritium breeding. HYLIFE-II is passively safe, having no large sources of energy available to disperse radioactive materials. The dominant activation product is 18 F (half-life 110 minutes). Only a small fraction ( -5 ) of the Flibe activation products would be mobilized. The offsite dose from a severe accident involving simultaneous failure of the blast chamber and containment building would be < 0.2 mSv (20 mrem), and N-stamp requirements could be avoided in the blast chamber and coolant systems. The required tritium removal efficiencies are quantified. 10 refs., 1 fig

Portable multiwire proportional chamber imaging system for high resolution 125I imaging

International Nuclear Information System (INIS)

Lazewatsky, J.L.; Lanza, R.C.; Murray, B.W.; Bolon, C.; Burns, R.E.; Szulc, M.

1976-01-01

A dedicated multiwire proportional chamber system designed to image 125 I labeled venous thrombi is described. The chamber is filled with a Kr-Co 2 gas mixture at one atmosphere pressure and utilizes an externally mounted delay line readout. A pair of crossed x-ray grids form a collimator which yields an optimum system efficiency of 3.1 x 10 -4 for a fixed spatial resolution of 0.74 cm. The chamber is further designed to be lightweight and portable for in-hospital use

The Evaluation of Solid Wastes Reduction with Combustion System in the Combustion Chamber

International Nuclear Information System (INIS)

Prayitno; Sukosrono

2007-01-01

The evaluation of solid wastes reduction with combustion system is used for weight reduction factor. The evaluation was done design system of combustion chamber furnace and the experiment was done by burning a certain weight of paper, cloth, plastic and rubber in the combustion chamber. The evaluation of paper wastes, the ratio of wastes (paper, cloth, plastic and rubber) against the factor of weight reduction (%) were investigated. The condition was dimension of combustion chamber furnace = 0.6 X 0.9 X 1.20 X 1 m with combustion chamber and gas chamber and reached at the wastes = 2.500 gram, oxygen pressure 0.5 Bar, wastes ratio : paper : cloth : plastic : rubber = 55 : 10 : 30 : 5, the reduction factor = 6.36 %. (author)

Drift chamber data readout system

International Nuclear Information System (INIS)

Basiladze, S.G.; Lokhonyai, L.

1980-01-01

An electronic system for processing drift chamber signals is described. The system consists of 4-channel fast amplifier-discriminators of low threshold, 16-channel time-expanders transforming 0.5 μs time intervals to 10 μs and a 9-bit time-to-digital converter (TDC) recording up to 16 expanded time intervals. If the average track multiplicity is small, TDC is capable to process signals from 4 time-expanders (i.e., 64 drift gaps). In order to record multiple tracks per drift gap discriminator outputs can be connected to a number of time-expander channels. The fast clear input enables the system to be cleared within 0.5 μs. Efficient readout from TDC is facilated by reading only those channels which contain non-zero data (9 bits - drift time; 6 bits - wire number)

A plant chamber system with downstream reaction chamber to study the effects of pollution on biogenic emissions.

Science.gov (United States)

Timkovsky, J; Gankema, P; Pierik, R; Holzinger, R

2014-01-01

A system of two plant chambers and a downstream reaction chamber has been set up to investigate the emission of biogenic volatile organic compounds (BVOCs) and possible effects of pollutants such as ozone. The system can be used to compare BVOC emissions from two sets of differently treated plants, or to study the photochemistry of real plant emissions under polluted conditions without exposing the plants to pollutants. The main analytical tool is a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) which allows online monitoring of biogenic emissions and chemical degradation products. The identification of BVOCs and their oxidation products is aided by cryogenic trapping and subsequent in situ gas chromatographic analysis.

A multiple sampling time projection ionization chamber for nuclear fragment tracking and charge measurement

International Nuclear Information System (INIS)

Bauer, G.; Bieser, F.; Brady, F.P.; Chance, J.C.; Christie, W.F.; Gilkes, M.; Lindenstruth, V.; Lynen, U.; Mueller, W.F.J.; Romero, J.L.; Sann, H.; Tull, C.E.; Warren, P.

1997-01-01

A detector has been developed for the tracking and charge measurement of the projectile fragment nuclei produced in relativistic nuclear collisions. This device, MUSIC II, is a second generation Multiple Sampling Ionization Chamber (MUSIC), and employs the principles of ionization and time projection chambers. It provides unique charge determination for charges Z≥6, and excellent track position measurement. MUSIC II has been used most recently with the EOS (equation of state) TPC and other EOS collaboration detectors. Earlier it was used with other systems in experiments at the Heavy Ion Superconducting Spectrometer (HISS) facility at Lawrence Berkeley Laboratory and the ALADIN spectrometer at GSI. (orig.)

Drift chamber and pulse height readout systems using analog multiplexing

International Nuclear Information System (INIS)

Cisneros, E.L; Kang, H.K.; Hall, J.N.; Larsen, R.S.

1976-11-01

Drift chamber and pulse-height readout systems are being developed for use in a new large scale detector at the SPEAR colliding beam facility. The systems are based upon 32 channels of sample-and-hold together with an analog multiplexer in a single-width CAMAC module. The modules within each crate are scanned by an autonomous controller containing a single ADC and memory plus arithmetic capability for offset, gain and linearity corrections. The drift chamber module has a facility for extracting hit wire information for use in trigger decision circuitry

The Mobile Chamber

Science.gov (United States)

Scharfstein, Gregory; Cox, Russell

2012-01-01

A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

Distributed remote temperature monitoring system for INDUS-2 vacuum chambers

International Nuclear Information System (INIS)

Bhange, N.J.; Gothwal, P.; Fatnani, P.; Shukla, S.K.

2011-01-01

Indus-2, a 2.5 GeV Synchrotron Radiation Source (SRS) at Indore has a large vacuum system. The vacuum envelope of Indus-2 ring comprises of 16 dipole chambers as vital parts. Each chamber has 4 photon absorbers and three beam line ports blanked with end flanges. Temperature monitoring of critical vacuum components during operation of Indus-2 ring is an important requirement. The paper discusses a distributed, 160 channel remote temperature monitoring system developed and deployed for this purpose using microcontroller based, modular Temperature Monitoring Units (TMU). The cabling has been extensively minimized using RS485 system and keeping trip relay contacts of all units in series. For ensuring proper signal conditioning of thermocouple outputs (K-type) and successful operation over RS485 bus, many precautions were taken considering the close proximity to the storage ring. We also discuss the software for vacuum chamber temperature monitoring and safety system. The software developed using LabVIEW, has important features like modularity, client-server architecture, local and global database logging, alarms and trips, event and error logging, provision of various important configurations, communications handling etc. (author)

Gamma compensated pulsed ionization chamber wide range neutron/reactor power measurement system

International Nuclear Information System (INIS)

Ellis, W.H.

1975-01-01

An improved method and system of pulsed mode operation of ionization chambers is described in which a single sensor system with gamma compensation is provided by sampling, squaring, automatic gate selector, and differential amplifier circuit means, employed in relation to chambers sensitized to neutron plus gamma and gamma only to subtract out the gamma component, wherein squaring functions circuits, a supplemental high performance pulse rate system, and operational and display mode selection and sampling gate circuits are utilized to provide automatic wide range linear measurement capability for neutron flux and reactor power. Neon is employed as an additive in the ionization chambers to provide independence of ionized gas kinetics temperature effects, and the pulsed mode of operation provide independence of high temperature insulator leakage effects. (auth)

Characterization of ionization chambers in double face for X-ray detection systems

International Nuclear Information System (INIS)

Costa, Alessandro M. da; Caldas, Linda V.O.

2000-01-01

Two identical parallel-plate ionization chambers with collecting electrodes of different materials (in order to obtain different energy dependences), developed at Instituto de Pesquisas Energeticas e Nucleares, were tested in low energy X-radiation beams, simulating a special ionization chamber, of double face, in a Tandem system. The purpose of this work is to justify a project of a double face detection system utilizing ionization chambers in Tandem. In relation to conventional methods, this kind of system will provide more efficient and precise absorbed dose in air measurements and radiation effective energy determinations. The results obtained in relation to characteristics of short- and long-term stabilities and angular and energy dependence show that the project is feasible and very appropriate. (author)

A multichannel automated chamber system for continuous measurement of forest soil CO2 efflux

International Nuclear Information System (INIS)

Liang, N.; Inoue, G.; Fujinuma, Y.

2003-01-01

Development of a fast-response multi-chamber system for measuring soil-surface carbon dioxide efflux is described. The sixteen-chamber automated system continuously monitors surface carbon dioxide efflux at different locations within a forest ecosystem using a single infrared gas analyzer that successively measures gas samples from each of the sixteen chambers. The chambers have lids that open and close automatically, and are connected in parallel to the single carbon dioxide analyzer which is equipped with a sixteen-channel gas sampler. Air is withdrawn continuously from the inlets and outlets of each chamber and fed sequentially to the gas analyzer. Using this instrument, surface carbon dioxide efflux was measured in a 40-year old pine forest during a three-month period (February to May) in 2001. Results showed a steady increase in mean carbon dioxide efflux during the period. A statistically significant correlation between soil-surface carbon dioxide efflux and surface temperature was also established. Spatial variation of carbon dioxide efflux was found to be higher in the non-growing season than in the growing season. It was concluded that the multi-channel automated chamber system can provide large amounts of high quality data on soil carbon dioxide efflux over a large surface area and simultaneously evaluate both spatial and temporal variation. The system uses a relatively small amount of power (70 W maximum) which can be further reduced (to 15 W) by minimizing the pressure difference between inside and outside the chamber. The system requires no maintenance other than the calibration of the gas analyzer and measurement of the flow rate through the chambers. 34 refs., 8 figs

Drift chamber system for use in a high rate environment

International Nuclear Information System (INIS)

Etkin, A.

1978-01-01

A system of short drift distance (0.125'') drift chambers is described. This system is being built for use in the Brookhaven National Laboratory Multiparticle Spectrometer. These chambers will be able to handle beam rates of several million/pulse and give a spatial resolution of the order of 150 μm. Cathode readout will provide unique 3-dimensional points for each crack. The readout will utilize three custom built integrated circuits, a four channel amplifier-shaper, a four channel discriminator and a four channel shift register delay and time digitizer. A summary of test results on a prototype is also given

Recent developments for the pattern recognition in the central drift chamber of the Belle II detector

Energy Technology Data Exchange (ETDEWEB)

Trusov, Viktor; Feindt, Michael; Heck, Martin; Hauth, Thomas; Goldenzweig, Pablo [Karlsruhe Institute of Technology (Germany); Collaboration: Belle II-Collaboration

2016-07-01

The Belle II experiment is designed to perform more precise measurements (e.g. C P-violation measurements, New Physics phenomena, rare decays etc) than its predecessor, the Belle experiment. To achieve this goal, the luminosity of the experiment will be increased by a factor of 40 and as result multiple times more data will be collected. Due to this fact, faster reconstruction algorithms for the data processing need to be developed and at the same time accurate physical results should be retained. One important part in the data processing chain is the track reconstruction section. We present the development of one of the pattern recognition algorithms for the Belle II experiment based on conformal and Legendre transformations. In order to optimize the performance of the algorithm (CPU time and efficiency) we have introduced specialized processing steps. To show improvements in the results we introduce efficiency measurements of the tracking algorithms in the Central Drift Chamber (CDC) which were done using Monte-Carlo simulation of e{sup +} e{sup -} collisions followed by a full simulation of the Belle II detector.

Multi-wire chamber system for heavy ion beam monitoring at the Bevalac

International Nuclear Information System (INIS)

Cuperus, J.; Morgado, R.

1975-03-01

Horizontal and vertical integrated beam-current profiles are generated by a system of multi-wire chambers (32 wires/profile) operating in either the ionization or proportional mode. Sixteen distinct displays (1024 words) are digitally stored and any four may be simultaneously displayed. A new display can be generated at 64 ms intervals. A central control unit selects the mode of operation, the amount of delay after an appropriate trigger, the chamber integration time, and the particular chambers to be displayed. Operating in the proportional mode, the system can detect relativistic heavy-ion beam intensities as low as 10 4 charges cm -2 sec -1 . (U.S.)

The vacuum system for the PEP II high energy ring straight sections

International Nuclear Information System (INIS)

Wienands, U.; Daly, E.; Heifets, S.A.; Kulikov, A.; Kurita, N.; Nordby, M.; Perkins, C.; Reuter, E.; Seeman, J.T.; Belser, F.C.; Berg, J.; Holdener, F.R.; Kerns, J.A.; McDaniel, M.R.; Stoeffl, W.

1995-01-01

The six straight sections of the PEP II High Energy Ring (HER) serve various functions: lattice tuning, beam injection and abort, providing space for rf cavities, longitudinal and transverse feedback, beam diagnostics and the interaction point. A stainless steel vacuum system has been designed; prototypes are currently being built. Cooling is required due to radiation coming from the last arc dipole and resistive losses in the vacuum chamber. Although the nominal beam current of the HER is 1 A the vacuum system is designed for 3 A to provide margin and an upgrade path. 5 refs., 7 figs

SLAC Scanner Processor applications in the data acquisition system for the upgraded Mark II detector

International Nuclear Information System (INIS)

Barklow, T.; Glanzman, T.; Lankford, A.J.; Riles, K.

1985-09-01

The SLAC Scanner Processor is a general purpose, programmable FASTBUS crate/cable master/slave module. This device plays a central role in the readout, buffering and pre-processing of data from the upgraded Mark II detector's new central drift chamber. In addition to data readout, the SSPs assist in a variety of other services, such as detector calibration, FASTBUS system management, FASTBUS system initialization and verification, and FASTBUS module testing. 9 refs., 1 fig., 2 tabs

High voltage pulse system for the streamer chamber supply of the GIBS spectrometer

International Nuclear Information System (INIS)

Aksinenko, V.D.; Glagoleva, N.S.; Dement'ev, E.A.; Kaminskij, N.I.; Matyushin, A.T.; Matyushin, V.T.; Rozhnyatovskaya, S.A.; Ryakhovskij, V.N.; Nurgozhin, N.N.; Khusainov, E.K.

1987-01-01

Results of development and testing of high voltage pulse system HVPS for the streamer chamber supply of the GIBS spectrometer are presented. HVPS consists of the following basic blocks: nanosecond pulse high voltage generator, high voltage charging supply, trigger generator, chamber parameter control devices, gas-oil vacuuming supply systems, auxiliary and fire-prevention devices. The system blocks are described. Experimental results of HVPC testing are presented. HVPC provides a reliable (10 5 operations) of streamer chamber supply with high voltage pulse parameters: amplitude - 500 kV, amplitude instability (0.5-1.5)%, pulse duration - 12 ns, delay time - 500 ns, delay instability (2.5-5)%, mean frequency of output a signals - 0.1 Hz

Electronic equipment of the extended system for beam diagnostics of the ''Lyudmila'' liquid-hydrogen chamber

International Nuclear Information System (INIS)

Basiladze, S.G.; Bulanov, N.F.; Nguen V'et Zung; Yudin, V.K.

1978-01-01

The electronic equipment of an expanded system of beam monitoring for the Lyudmila liquid-hydrogen bubble chamber is described. The system contains ten proportional chambers: nine two-coordinate and one one-coordinate chambers, spacing being 1 mm. The total number of wires is 912. Signals are measured in parallel from all the 48 wires for any plane, or for two planes from even and odd wires. The electronic equipment includes preamplifiers on a field transistor, charge-digital converters, and followers. The electronic circuits in the chambers are distinguished by simplicity and low power consumption: one transistor and 1 mW per wire respectively. The system operates with a small TPA-i computer

Microwave remote plasma enhanced-atomic layer deposition system with multicusp confinement chamber.

Science.gov (United States)

Dechana, A; Thamboon, P; Boonyawan, D

2014-10-01

A microwave remote Plasma Enhanced-Atomic Layer Deposition system with multicusp confinement chamber is established at the Plasma and Beam Physics research facilities, Chiang Mai, Thailand. The system produces highly-reactive plasma species in order to enhance the deposition process of thin films. The addition of the multicusp magnetic fields further improves the plasma density and uniformity in the reaction chamber. Thus, the system is more favorable to temperature-sensitive substrates when heating becomes unwanted. Furthermore, the remote-plasma feature, which is generated via microwave power source, offers tunability of the plasma properties separately from the process. As a result, the system provides high flexibility in choice of materials and design experiments, particularly for low-temperature applications. Performance evaluations of the system were carried on coating experiments of Al2O3 layers onto a silicon wafer. The plasma characteristics in the chamber will be described. The resulted Al2O3 films-analyzed by Rutherford Backscattering Spectrometry in channeling mode and by X-ray Photoelectron Spectroscopy techniques-will be discussed.

Microwave remote plasma enhanced-atomic layer deposition system with multicusp confinement chamber

Energy Technology Data Exchange (ETDEWEB)

Dechana, A. [Program of Physics and General Science, Faculty of Science and Technology, Songkhla Rajabhat University, Songkhla 90000 (Thailand); Thamboon, P. [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Boonyawan, D., E-mail: dheerawan.b@cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

2014-10-15

A microwave remote Plasma Enhanced-Atomic Layer Deposition system with multicusp confinement chamber is established at the Plasma and Beam Physics research facilities, Chiang Mai, Thailand. The system produces highly-reactive plasma species in order to enhance the deposition process of thin films. The addition of the multicusp magnetic fields further improves the plasma density and uniformity in the reaction chamber. Thus, the system is more favorable to temperature-sensitive substrates when heating becomes unwanted. Furthermore, the remote-plasma feature, which is generated via microwave power source, offers tunability of the plasma properties separately from the process. As a result, the system provides high flexibility in choice of materials and design experiments, particularly for low-temperature applications. Performance evaluations of the system were carried on coating experiments of Al{sub 2}O{sub 3} layers onto a silicon wafer. The plasma characteristics in the chamber will be described. The resulted Al{sub 2}O{sub 3} films—analyzed by Rutherford Backscattering Spectrometry in channeling mode and by X-ray Photoelectron Spectroscopy techniques—will be discussed.

Microwave remote plasma enhanced-atomic layer deposition system with multicusp confinement chamber

Science.gov (United States)

Dechana, A.; Thamboon, P.; Boonyawan, D.

2014-10-01

A microwave remote Plasma Enhanced-Atomic Layer Deposition system with multicusp confinement chamber is established at the Plasma and Beam Physics research facilities, Chiang Mai, Thailand. The system produces highly-reactive plasma species in order to enhance the deposition process of thin films. The addition of the multicusp magnetic fields further improves the plasma density and uniformity in the reaction chamber. Thus, the system is more favorable to temperature-sensitive substrates when heating becomes unwanted. Furthermore, the remote-plasma feature, which is generated via microwave power source, offers tunability of the plasma properties separately from the process. As a result, the system provides high flexibility in choice of materials and design experiments, particularly for low-temperature applications. Performance evaluations of the system were carried on coating experiments of Al2O3 layers onto a silicon wafer. The plasma characteristics in the chamber will be described. The resulted Al2O3 films—analyzed by Rutherford Backscattering Spectrometry in channeling mode and by X-ray Photoelectron Spectroscopy techniques—will be discussed.

Microwave remote plasma enhanced-atomic layer deposition system with multicusp confinement chamber

International Nuclear Information System (INIS)

Dechana, A.; Thamboon, P.; Boonyawan, D.

2014-01-01

A microwave remote Plasma Enhanced-Atomic Layer Deposition system with multicusp confinement chamber is established at the Plasma and Beam Physics research facilities, Chiang Mai, Thailand. The system produces highly-reactive plasma species in order to enhance the deposition process of thin films. The addition of the multicusp magnetic fields further improves the plasma density and uniformity in the reaction chamber. Thus, the system is more favorable to temperature-sensitive substrates when heating becomes unwanted. Furthermore, the remote-plasma feature, which is generated via microwave power source, offers tunability of the plasma properties separately from the process. As a result, the system provides high flexibility in choice of materials and design experiments, particularly for low-temperature applications. Performance evaluations of the system were carried on coating experiments of Al 2 O 3 layers onto a silicon wafer. The plasma characteristics in the chamber will be described. The resulted Al 2 O 3 films—analyzed by Rutherford Backscattering Spectrometry in channeling mode and by X-ray Photoelectron Spectroscopy techniques—will be discussed

Advanced Materials and Manufacturing for Low-Cost, High-Performance Liquid Rocket Combustion Chambers, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Silicided niobium alloy (C103) combustion chambers have been used extensively in both NASA and DoD liquid rocket propulsion systems. Niobium alloys offer a good...

Multi-probe ionization chamber system for nuclear-generated plasma diagnostics

International Nuclear Information System (INIS)

Choi, W.Y.; Ellis, W.H.

1990-01-01

This paper reports on the pulsed ionization chamber (PIC) plasma diagnostic system used in studies of nuclear seeded plasma kinetics upgraded to increase the capabilities and extend the range of plasma parameter measurements to higher densities and temperatures. The PIC plasma diagnostic chamber has been provided with additional measurement features in the form of conductivity and Langmuir probes, while the overall experimental system has been fully automated, with computerized control, measurement, data acquisition and analysis by means of IEEE-488 (GPIB) bus control and data transfer protocols using a Macintosh series microcomputer. The design and use of a simple TTL switching system enables remote switching among the various GPIB instruments comprising the multi-probe plasma diagnostic system using software, without the need for a microprocessor. The new system will be used to extend the present study of nuclear generated plasma in He, Ar, Xe, fissionable UF 6 and other fluorine containing gases

The CDF II eXtremely fast tracker upgrade

Energy Technology Data Exchange (ETDEWEB)

Abulencia, A.; Azzurri, P.; Cochran, E.; Dittmann, J.; Donati, S.; Efron, J.; Erbacher, R.; Errede, D.; Fedorko, I.; Flanagan, G.; Forrest, R.; /Illinois U., Urbana

2006-09-01

The CDF II Extremely Fast Tracker is the trigger track processor which reconstructs charged particle tracks in the transverse plane of the CDF II central outer tracking chamber. The system is now being upgraded to perform a three dimensional track reconstruction. A review of the upgrade is presented here.

Ussing Chamber

NARCIS (Netherlands)

Westerhout, J.; Wortelboer, H.; Verhoeckx, K.

2015-01-01

The Ussing chamber system is named after the Danish zoologist Hans Ussing, who invented the device in the 1950s to measure the short-circuit current as an indicator of net ion transport taking place across frog skin (Ussing and Zerahn, Acta Physiol Scand 23:110-127, 1951). Ussing chambers are

The Laser Calibration System of the ALICE Time Projection Chamber

CERN Document Server

Renault, G; Nielsen, B S; Westergaard, J

2005-01-01

A Large Ion Collider Experiment (ALICE) is the only experiment at the Large Hadron Collider (LHC) dedicated to the study of heavy ion collisions. The Time Projection Chamber (TPC) is the main tracking detector covering the pseudo rapidity range $|\\eta|< 0.9$. It is designed for a maximum multiplicity \\dNdy = 8000. The aim of the laser system is to simulate ionizing tracks at predifined positions throughout the drift volume in order to monitor the TPC response to a known source. In particular, the alignment of the read-out chambers will be performed, and variations of the drift velocity due to drift field imperfections can be measured and used as calibration data in the physics data analysis. In this paper we present the design of the pulsed UV laser and optical system, together with the control and monitoring systems.

Unified Analysis of Multi-Chamber Contact Tanks and Mixing Efficiency Evaluation Based on Vorticity Field. Part II: Transport Analysis

Directory of Open Access Journals (Sweden)

Ender Demirel

2016-11-01

Full Text Available Mixing characteristics of multi-chambered contact tank are analyzed employing the validated three-dimensional numerical model developed in the companion paper. Based on the flow characterization, novel volumetric mixing efficiency definitions are proposed for the assessment of the hydrodynamic and chemical transport properties of the contact tank and its chambers. Residence time distribution functions are analyzed not only at the outlet of each chamber but also inside the chambers using the efficiency definitions for both Reynolds averaged Navier–Stokes (RANS and large eddy simulation (LES results. A novel tracer mixing index is defined to characterize short circuiting and mixing effects of the contact system. Comparisons of the results of these indexes for RANS and LES solutions indicate that mixing characteristics are stronger in LES due to the unsteady turbulent eddy mixing even though short circuiting effects are also more prominent in LES results. This result indicates that the mixing analysis based on the LES results simulates the mixing characteristics instantaneously, which is more realistic than that in RANS. Since LES analysis can capture turbulent eddy mixing better than RANS analysis, the interaction of recirculation and jet zones are captured more effectively in LES, which tends to predict higher turbulent mixing in the contact system. The analysis also shows that the mixing efficiency of each chamber of the contact tank is different, thus it is necessary to consider distinct chemical release and volumetric designs for each chamber in order to maximize the mixing efficiency of the overall process in a contact tank system.

Design of data acquisition system for 2D-ARRAY ionization chamber detector

International Nuclear Information System (INIS)

He Chaohui; Xing Guilai; Wu Zhifang; Wang Zhentao

2012-01-01

The introduction is given on the design and development of data acquisition system for 2D-ARRAY ionization chamber detector, which is used for dose verification of tumor radiotherapy. The paper describes the structure and the principle of the 2D-ARRAY ionization chamber detector system in detail, and focuses on the discussion on the design process of the detector's data acquisition system and the development of data acquisition system which is constituted by preamplifier, preamplifier control board and data acquisition board. The client can setup the parameters of the detector system via TCP/IP and do data processing such as high speed data collection and acquisition, further operation and so on. (authors)

Ion chamber-electrometer measurement system for radiation protection tests in X-ray equipment for interventional procedures

International Nuclear Information System (INIS)

Bottaro, Marcio

2012-01-01

A new parallel plate ionization chamber with volume of 500 cc and an electrometer with digital interface for data acquisition, configuring an ion chamber electrometer measurement system, were developed to comply with specific requirements for compulsory radiation protection tests in interventional X-ray equipment. The ion chamber has as main characteristics: low cost, mechanical strength and response variation with beam energy of less than 5% in the 40 kV to 150 kV range. The electrometer has a high gain (5x10 8 V/A) transimpedance amplifier circuit and a data acquisition and control system developed in LabVIEW ® platform, including an integrated power supply for the ion chamber bias with adjustable DC voltage output from O to 1000 V and an air density correction system. Electric field calculations, laboratory measurements in standard beams and computational simulations of radiation interactions in chamber volume with Monte Carlo Method were employed in the elaborated methodology of the ion chamber development, which was tested and validated. It was also developed a simplified methodology for electrometer calibration that assures metrological trustworthiness of the measurement system. Tests for the system performance evaluation as environmental influence response, energy response, angular dependency, linearity and air kerma and air kerma rate dependency were performed according to international standards and requirements. Additionally, for a detailed evaluation of the developed ion chamber, simulations with various scattered radiation spectra were performed. The system was applied in leakage radiation, residual radiation and scattered radiation tests, being compared with other reference systems and validated for laboratorial test routine. (author)

Multiple Coronary Chamber Microfistulas or Persistent Thebesian Vessels?

Directory of Open Access Journals (Sweden)

Cernica Daniel

2017-09-01

Full Text Available Coronary fistulas are rare, not gender-specific congenital conditions, consisting of communications between the coronary arteries and either another coronary vessel or a cardiac chamber. In contrast to large fistulas, small fistulas, named “minimae cordis veneae” or the Thebesius venous system, are draining into heart chambers and form a vascular network in the cardiac lumen. In this article, we present the case of a 72-year-old female with a significant history of cardiovascular disease, admitted to our clinic because of rest dyspnea, fatigue, and minimal chest pain. The 12-lead electrocardiogram showed a trifascicular block (a second-degree atrioventricular block Mobitz II, associated with a right bundle branch block and left anterior fascicle block and negative T waves in DII, DIII, aVF, V4–V6 leads. An invasive coronary angiography was performed, which revealed no significant atherosclerotic lesions. However, a persistent capillary blush was present at the apex site of the left ventricular chamber, draining from the distal segments of both the anterior descending coronary artery and the posterior interventricular coronary artery. The intramural vascular network generating a left ventricle angiogram image of this kind was suggestive for persistent Thebesian vessels connecting the two coronaries with the left ventricular chamber.

Conceptual design of the fast ignition laser fusion power plant (KOYO-Fast). 6. Design of chamber and reactor system

International Nuclear Information System (INIS)

Kozaki, Yasuji; Norimatsu, Takayoshi; Furukawa, Hiroyuki; Hayashi, Takumi; Souman, Yoshihito; Nishikawa, Masabumi; Tomabechi, Ken

2007-01-01

A conceptual design of the reactor chamber system with LiPb liquid wall based on the fast ignition cone target design and the related reactor systems with exhaust system, laser beam shutter, blanket and cooling system are summarized. The multi overflow fall method was investigated as the structure of chamber and repeating 4 Hz pulse potential. The ablation depth of LiPb liquid wall was estimated and the conditions of repeat of operation were evaluated. The basic design of chamber, selection and conditions of liquid wall chamber, recycle type multi overflow fall (MOF) wall, LiPb two layers blanket structure, basic specification of reactor system, laser beam line shutter, design of chamber exhaust system, cooling system, tritium recovery system, power plant total design and arrangement of chamber and laser beam, and issues are stated. (S.Y.)

The laser system for calibration and monotoring of the Opal jet chamber

International Nuclear Information System (INIS)

Biebel, O.; Boden, B.; Bug, S.; Eyring, A.; Fischer, H.M.; Geich-Gimbel, C.; Gross, S.; Knop, G.; Levegruen, S.; Maringer, G.; Mauer, E.; Maur, U.; Nellen, B.; Neumann, H.; Rollnik, A.; Schreiber, S.; Simon, A.; Thiebes, J.; Wolf, B.; Wuensch, B.; Boerner, H.; Breuker, H.; Hagemann, J.; Hauschild, M.; Heuer, R.D.; Karner, K.; Linser, G.; Runolfsson, O.; Seidl, W.; Voillat, D.; Wicht, P.; Schmitt, H. von der; Wagner, A.

1992-01-01

In this report we describe the construction and performance of the laser system which was used in Summer 1989 for the initial calibration of the OPAL jet chamber after installation on the LEP beam axis and which has served as a monitoring tool since then. Two Nd:YAG lasers are used to generate 48 high precision double beams which enter the chamber at fixed positions. The main features of the roughly 450 optical components are described and the beam alignment procedures are explained. Results are given for jet chamber calibration constants such as drift velocity, Lorentz angle, and residual sagittas. (orig.)

Wire chamber requirements and tracking simulation studies for tracking systems at the superconducting super collider

International Nuclear Information System (INIS)

Hanson, G.G.; Niczyporuk, B.B.; Palounek, A.P.T.

1989-02-01

Limitations placed on wire chambers by radiation damage and rate requirements in the SSC environment are reviewed. Possible conceptual designs for wire chamber tracking systems which meet these requirements are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. Such computer simulation studies are necessary to determine the feasibility of wire chamber tracking systems for complex events in a high-rate environment such as the SSC. 11 refs., 9 figs., 1 tab

Climatic chamber ergometer

CSIR Research Space (South Africa)

Atkins, AR

1968-01-01

Full Text Available The design and calibration of an ergometer for exercising subjects during calorimetric studies in the climate chamber, are described. The ergometer is built into the climatic chamber and forms an integral part of the whole instrumentation system foe...

Picture chamber for radiographic system

International Nuclear Information System (INIS)

1977-01-01

The picture chamber for a radiographic system is characterised by a base, a first electrode carried in the base, an X-ray irradiation window provided with an outer plate and an inner plate and a conducting surface which serves as a second electrode, which has a plate gripping it at each adjacent edge and which has at the sides a space which is occupied by a filling material, maintained at a steady pressure, by means of the mounting against the base and wherein the inner plate lies against the first electrode and which is provided with a split, and with means for the separation of the split in the area of the inner plate so that a fluid may be retained in the split. (G.C.)

Design and construction of an interface system for the extrapolation chamber from the beta secondary standard

International Nuclear Information System (INIS)

Jimenez C, L.F.

1995-01-01

The Interface System for the Extrapolation Chamber (SICE) contains several devices handled by a personal computer (PC), it is able to get the required data to calculate the absorbed dose due to Beta radiation. The main functions of the system are: a) Measures the ionization current or charge stored in the extrapolation chamber. b) Adjusts the distance between the plates of the extrapolation chamber automatically. c) Adjust the bias voltage of the extrapolation chamber automatically. d) Acquires the data of the temperature, atmospheric pressure, relative humidity of the environment and the voltage applied between the plates of the extrapolation chamber. e) Calculates the effective area of the plates of the extrapolation chamber and the real distance between them. f) Stores all the obtained information in hard disk or diskette. A comparison between the desired distance and the distance in the dial of the extrapolation chamber, show us that the resolution of the system is of 20 μm. The voltage can be changed between -399.9 V and +399.9 V with an error of less the 3 % with a resolution of 0.1 V. These uncertainties are between the accepted limits to be used in the determination of the absolute absorbed dose due to beta radiation. (Author)

System of cylindrical drift chambers in a superconducting solenoid

International Nuclear Information System (INIS)

Camilleri, L.; Blumenfeld, B.J.; Dimcovski, Z.

1978-01-01

A superconducting solenoid at the CERN ISR was equipped with a system of high accuracy cylindrical drift chambers. This detector consists of eight layers of field shaped drift cells with a delay line opposite each sense wire to provide coupled two dimensional readout. The design, construction, and operation of this system are discussed. The resolution and performance of the delay lines and sense wires under ISR running conditions are shown

Modelling of a general purpose irradiation chamber using a Monte Carlo particle transport code

International Nuclear Information System (INIS)

Dhiyauddin Ahmad Fauzi; Sheik, F.O.A.; Nurul Fadzlin Hasbullah

2013-01-01

Full-text: The aim of this research is to stimulate the effectiveness use of a general purpose irradiation chamber to contain pure neutron particles obtained from a research reactor. The secondary neutron and gamma particles dose discharge from the chamber layers will be used as a platform to estimate the safe dimension of the chamber. The chamber, made up of layers of lead (Pb), shielding, polyethylene (PE), moderator and commercial grade aluminium (Al) cladding is proposed for the use of interacting samples with pure neutron particles in a nuclear reactor environment. The estimation was accomplished through simulation based on general Monte Carlo N-Particle transport code using Los Alamos MCNPX software. Simulations were performed on the model of the chamber subjected to high neutron flux radiation and its gamma radiation product. The model of neutron particle used is based on the neutron source found in PUSPATI TRIGA MARK II research reactor which holds a maximum flux value of 1 x 10 12 neutron/ cm 2 s. The expected outcomes of this research are zero gamma dose in the core of the chamber and neutron dose rate of less than 10 μSv/ day discharge from the chamber system. (author)

Remote Control System of the TJ-II Microwave Transmission Lines Mirrors; Sistema de Control Remoto de los Espejos de las Lineas de Transmision de Microondas del TJ-II

Energy Technology Data Exchange (ETDEWEB)

Lopez Sanchez, A.; Fernandez, A.; Cappa, A.; Gama, J. de la; Olivares, J.; Garcia, R.; Chamorro, M.

2007-09-27

The ECRH system of the TJ-II stellarator has two gyrotrons, which deliver a maximum power of 300 kW each at a frequency of 53.2 GHz. Another 28 GHz gyrotron will be used to heat the plasma by electron Bernstein waves (EBWH). The microwave power is transmitted from the gyrotrons to the vacuum chamber by two quasi-optical transmission lines for ECRH and a corrugated waveguide for EBWH. All transmission lines have an internal movable mirror inside the vacuum chamber to focus the beam and to be able to change the launching angle. The control of the beam polarization is very important and the lines have two corrugated mirrors, which actuate as polarizers. In this report the control system of the position of these three internal mirrors and the polarizers of the EBWH transmission line is described. (Author) 20 refs.

DELPHI Barrel Muon Chamber Module

CERN Multimedia

1989-01-01

The module was used as part of the muon identification system on the barrel of the DELPHI detector at LEP, and was in active use from 1989 to 2000. The module consists of 7 individual muons chambers arranged in 2 layers. Chambers in the upper layer are staggered by half a chamber width with respect to the lower layer. Each individual chamber is a drift chamber consisting of an anode wire, 47 microns in diameter, and a wrapped copper delay line. Each chamber provided 3 signal for each muon passing through the chamber, from which a 3D space-point could be reconstructed.

Project, construction and characterization of ionization chambers for use as standard systems in X and gamma radiation beams

International Nuclear Information System (INIS)

Perini, Ana Paula

2013-01-01

Ionization chambers present some advantages in relation to other dosimeters: easiness of handling, low energy dependence and high precision. The advantages associated to ionization chambers and the large number of diagnostic radiology exams and therapeutic treatments motivated the development of this PhD program. In this project ionization chambers were developed and characterized to be applied in diagnostic radiology and therapy beam dosimetry, with high precision and performance, in compliance with international recommendations. They were assembled in a simple way, utilizing low-cost national materials, so they can be reproduced and applied at calibration laboratories. The project of these ionization chambers presents some differences in relation to commercial ionization chambers, as the materials utilized and geometrical arrangements. Besides the development of the ionization chambers to be utilized in standard X-ray beam dosimetry as work standard systems, two graphite parallel-plate ionization chambers were developed and characterized to be applied as reference standard systems for determining the air kerma rates of gamma radiation sources. Comparing the air kerma rates determined with the reference standard of the Calibration Laboratory of IPEN, a Farmer ionization chamber, with the values of the air kerma rates obtained with the graphite ionization chambers, the maximum differences obtained were only 1.7% and 1.2% for the G1 and G2 graphite ionization chambers, respectively. Moreover, these ionization chambers presented correction factors close to 1.000, which is ideal for an ionization chamber be characterized as a reference standard system. (author)

Gas microstrip chambers

International Nuclear Information System (INIS)

McIntyre, P.M.; Barasch, E.F.; Bowcock, T.J.V.; Demroff, H.P.; Elliott, S.M.; Howe, M.R.; Lee, B.; Mazumdar, T.K.; Pang, Y.; Smith, D.D.; Wahl, J.; Wu, Y.; Yue, W.K.; Gaedke, R.M.; Vanstraelen, G.

1992-01-01

The gas microstrip chamber has been developed from concept to experimental system during the past three years. A pattern of anode and grid lines are microfabricated onto a dielectric substrate and configured as a high-resolution MWPC. Four recent developments are described: Suitable plastic substrates and lithography techniques for large-area chambers; non-planar silicon-based chambers for 20 μm resolution; integrated on-board synchronous front-end electronics and data buffering; and a porous silicon active cathode for enhanced efficiency and time response. The microstrip chamber appears to be a promising technology for applications in microvertex, tracking spectrometer, muon spectrometer, and transition radiation detection. (orig.)

Recent developments in high precision vertex chambers at SLAC

International Nuclear Information System (INIS)

Rust, D.R.

1984-04-01

Three detectors MARK II, MAC, AND HRS are using or planning small drift chambers placed as close as possible to the interaction print at PEP. There is also a program of development for a gaseous vertex detector for MARK II at SLC. All these programs are reviewed. 13 references

Tests of the data acquisition system and detector control system for the muon chambers of the CMS experiment at the LHC

CERN Document Server

Sowa, Michael Christian

The Phys. Inst. III A of RWTH Aachen University is involved in the development, production and tests of the Drift Tube (DT) muon chambers for the barrel muon system of the CMS detector at the LHC at CERN (Geneva). The thesis describes some test procedures which were developed and performed for the chamber local Data Acquisition (DAQ) system, as well as for parts of the Detector Control System (DCS). The test results were analyzed and discussed. Two main kinds of DAQ tests were done. On the one hand, to compare two different DAQ systems, the chamber signals were split and read out by both systems. This method allowed to validate them by demonstrating, that there were no relevant differences in the measured drift times, generated by the same muon event in the same chamber cells. On the other hand, after the systems were validated, the quality of the data was checked. For this purpose extensive noise studies were performed. The noise dependence on various parameters (threshold, HV) was investigated quantitativel...

Electromagnetic reverberation chambers

CERN Document Server

Besnier, Philippe

2013-01-01

Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

A 4π scintillation counter-optical spark chamber system for neutral particles

International Nuclear Information System (INIS)

Demarzo, C.; Distante, A.; Guerriero, L.; Niccolini, C.; Posa, F.; Walder, F.; Chen, G.T.Y.; Fletcher, C.R.; Lanou, R.E. Jr.; Thornton, R.K.; Barton, D.S.; Lyons, T.; Marx, M.; Rosenson, L.; Thern, R.

1975-01-01

The authors describe a scintillation counter-optical spark chamber system developed for the detection of high energy gamma rays and neutrons. They describe the system components and their use in two completed experiments. (Auth.)

Construction update and drift velocity calibration for the CLAS drift chamber system

International Nuclear Information System (INIS)

Mestayer, M.D.; Barbosa, F.J.; Bonneau, P.; Burtin, E.; Christo, S.; Doolittle, G.; Dytman, S.A.; Gilfoyle, G.P.; Hyde-Wright, C.E.; Klein, A.; Kossov, M.V.; Kuhn, S.E.; Magahiz, R.; Miskimen, R.A.; Murphy, L.Y.; O'Meara, J.E.; Pyron, T.D.; Qin, L.; Raue, B.A.; Schumacher, R.A.; Tuzel, W.; Weinstein, L.B.; Yegneswaran, A.

1995-01-01

We briefly describe the drift chamber system for the CLAS detector at CEBAF, concentrating on the method which will be used to calibrate the drift velocity function. We identify key features of the function which should apply to any small-cell drift chamber geometry in which the cathode and anode surfaces are wires. Using these ideas, we describe a simple method to compensate for variations in the drift velocity function due to environmental changes. (orig.)

Construction update and drift velocity calibration for the CLAS drift chamber system

Energy Technology Data Exchange (ETDEWEB)

Mestayer, M.D. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States); Barbosa, F.J. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States); Bonneau, P. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States); Burtin, E. [University of South Carolina, Columbia, SC (United States); Christo, S. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States); Doolittle, G. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States); Dytman, S.A. [University of Pittsburg, Pittsburg, PA (United States); Gilfoyle, G.P. [University of Richmond, Richmond, VA (United States); Hyde-Wright, C.E. [Old Dominion University, Norfolk, VA (United States); Klein, A. [Old Dominion University, Norfolk, VA (United States); Kossov, M.V. [Christopher Newport University, Newport News, VA (United States); Kuhn, S.E. [Old Dominion University, Norfolk, VA (United States); Magahiz, R. [Carnegie-Mellon Univ., Pittsburgh, PA (United States); Miskimen, R.A. [University of Massachussetts, Amherst, MA (United States); Murphy, L.Y. [CE Saclay, Gif sur Yvette (France); O`Meara, J.E. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States); Pyron, T.D. [Old Dominion University, Norfolk, VA (United States); Qin, L. [Old Dominion University, Norfolk, VA (United States); Raue, B.A. [Old Dominion University, Norfolk, VA (United States); Schumacher, R.A. [Carnegie-Mellon Univ., Pittsburgh, PA (United States); Tuzel, W. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States); Weinstein, L.B. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States); Yegneswaran, A. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States)

1995-12-11

We briefly describe the drift chamber system for the CLAS detector at CEBAF, concentrating on the method which will be used to calibrate the drift velocity function. We identify key features of the function which should apply to any small-cell drift chamber geometry in which the cathode and anode surfaces are wires. Using these ideas, we describe a simple method to compensate for variations in the drift velocity function due to environmental changes. (orig.).

Clean-up system for pool water in pressure suppression chamber and operation method therefor

Energy Technology Data Exchange (ETDEWEB)

Hirabayashi, Kentaro; Kinoshita, Shoichiro

1996-09-17

Pool water in a pressure suppression chamber of a BWR type reactor is sucked by a pump of an after-heat removing system. The pool water pressurized here is sent to the pressure suppression chamber by way of a heat exchanger and a test line backwarding pipeline to stir the pool water in the pressure suppression chamber. Further, the pool water pressurized by the pump is sent to the pressure suppression chamber by way of a filtration desalting device and an exit pipe to purify the pool water. Upon cleaning of pipelines before the start of a periodical test, the pool water sucked by the pump is sent to the filtration desalting device and recovered to the pressure suppression chamber. This can reduce the amount of impurities carried to the suppression chamber. After the cleaning of the pipelines, pool water is passed through the test line backwarding pipeline, so that the pool water can be stirred at the same time. (I.N.)

Peltier-based cloud chamber

Science.gov (United States)

Nar, Sevda Yeliz; Cakir, Altan

2018-02-01

Particles produced by nuclear decay, cosmic radiation and reactions can be identified through various methods. One of these methods that has been effective in the last century is the cloud chamber. The chamber makes visible cosmic particles that we are exposed to radiation per second. Diffusion cloud chamber is a kind of cloud chamber that is cooled by dry ice. This traditional model has some application difficulties. In this work, Peltier-based cloud chamber cooled by thermoelectric modules is studied. The new model provided uniformly cooled base of the chamber, moreover, it has longer lifetime than the traditional chamber in terms of observation time. This gain has reduced the costs which spent each time for cosmic particle observation. The chamber is an easy-to-use system according to traditional diffusion cloud chamber. The new model is portable, easier to make, and can be used in the nuclear physics experiments. In addition, it would be very useful to observe Muons which are the direct evidence for Lorentz contraction and time expansion predicted by Einsteins special relativity principle.

Drift chamber

International Nuclear Information System (INIS)

Inagaki, Yosuke

1977-01-01

Drift chamber is becoming an important detector in high energy physics as a precision and fast position detector because of its high spatial resolution and count-rate. The basic principle is that it utilizes the drift at constant speed of electrons ionized along the tracks of charged particles towards the anode wire in the nearly uniform electric field. The method of measuring drift time includes the analog and digital ones. This report describes about the construction of and the application of electric field to the drift chamber, mathematical analysis on the electric field and equipotential curve, derivation of spatial resolution and the factor for its determination, and selection of gas to be used. The performance test of the chamber was carried out using a small test chamber, the collimated β source of Sr-90, and 500 MeV/C electron beam from the 1.3 GeV electron synchrotron in the Institute of Nuclear Study, University of Tokyo. Most chambers to date adopted one dimensional read-out, but it is very advantageous if the two dimensional read-out is feasible with one chamber when the resolution in that direction is low. The typical methods of delay line and charge division for two dimensional read-out are described. The development of digital read-out system is underway, which can process the signal of a large scale drift chamber at high speed. (Wakatsuki, Y.)

21 CFR 864.9575 - Environmental chamber for storage of platelet concentrate.

Science.gov (United States)

2010-04-01

... to hold platelet-rich plasma within a preselected temperature range. (b) Classification. Class II... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Environmental chamber for storage of platelet... Establishments That Manufacture Blood and Blood Products § 864.9575 Environmental chamber for storage of platelet...

Numerical modeling and investigation of two-phase reactive flow in a high-low pressure chambers system

International Nuclear Information System (INIS)

Cheng, Cheng; Zhang, Xiaobing

2016-01-01

Highlights: • A novel two-dimensional two-phase flow model is established for the high-low pressure chambers system. • A strong packing of particles is observed at the projectile base and will cause the pressure to rise faster. • Different length–diameter ratios can affect the flow behavior through the vent-holes obviously. • The muzzle velocity decreases with the length–diameter ratio of the high-pressure chamber. - Abstract: A high-low pressure chambers system is proposed to meet the demands of low launch acceleration for informative equipment in many special fields such as Aeronautics, Astronautics and Weaponry. A two-dimensional two-phase flow numerical model is established to describe the complex physical process based on a modified two-fluid theory, which takes into account gas production, interphase drag, intergranular stress, and heat transfer between two phases. In order to reduce the computational cost, the parameters in the high-pressure chamber at the instant the vent-holes open are calculated by the zero-dimensional model as the initial conditions for the two-phase flow simulation in the high-low pressure chambers system. The simulation results reveal good agreement with the experiments and the launch acceleration of a projectile can be improved by this system. The propellant particles can be tracked clearly in both chambers and a strong packing of particles at the base of projectile will cause the pressure to rise faster than at other areas both in the axis and radial directions. The length–diameter ratio of the high-pressure chamber (a typical multi-dimensional parameter) is investigated. Different length–diameter ratios can affect the maximum pressure drop and the loss of total pressure impulse through the vent-hole, then the muzzle velocity and the launch acceleration of projectiles can be influenced directly. This article puts forward a new prediction tool for the understanding and design of transient processes in high-low pressure

OPAL Jet Chamber Prototype

CERN Multimedia

OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

Argus drift chamber

Energy Technology Data Exchange (ETDEWEB)

Danilov, M; Nagovizin, V; Hasemann, H; Michel, E; Schmidt-Parzefall, W; Wurth, R; Kim, P

1983-11-15

The ARGUS detector came into operation at the DORIS-II e/sup +/s/sup -/ storage ring at the end of 1982. Its two meter long drift chamber contains 5940 sense and 24588 field wires organized in uniform 18x18.8 mm/sup 2/ drift cells filling the whole volume. These cells form 36 layers, 18 of which provide stereo views. Each sense wire is equipped with a single hit TDC and ADC for coordinate and dE/dx measurements. The chamber is operated with propane to improve momentum and dE/dx resolution. The drift chamber design and initial performance are presented. With a very crude space-time relation approximation and without all the necessary corrections applied a spatial resolution of about 200 ..mu..m was obtained for half of the drift cell volume. Further corrections should improve this result. An intrinsic dE/dx resolution of 4.2% and an actual resolution of 5% were obtained for cosmic muons and also for Bhabha scattered electrons. An actual dE/dx resolution of 5.6% was obtained for pions from e/sup +/e/sup -/ annihilation data with almost no track selection. A relativistic rise of 30% was observed in good agreement with theory. The long-term stability is still to be investigated.

The KEK 1 m hydrogen bubble chamber

International Nuclear Information System (INIS)

Doi, Yoshikuni; Araoka, Osamu; Hayashi, Kohei; Hayashi, Yoshio; Hirabayashi, Hiromi.

1978-03-01

A medium size hydrogen bubble chamber has been constructed at the National Laboratory for High Energy Physics, KEK. The bubble chamber has been designed to be operated with a maximum rate of three times per half a second in every two second repetition time of the accelerator, by utilizing a hydraulic expansion system. The bubble chamber has a one meter diameter and a visible volume of about 280 l. A three-view stereo camera system is used for taking photographic pictures of the chamber. A 2 MW bubble chamber magnet is constructed. The main part of the bubble chamber vessel is supported by the magnet yoke. The magnet gives a maximum field of 18.4 kG at the centre of the fiducial volume of the chamber. The overall system of the KEK 1 m hydrogen bubble chamber facility is described in some detail. Some operational characteristics of the facility are also reported. (auth.)

Ionization chambers

International Nuclear Information System (INIS)

Boag, J.W.

1987-01-01

Although a variety of solid-state and chemical methods for measuring radiation dose have been developed in recent decades and calorimetry can now provide an absolute standard of reference, ionization dosimetry retains its position as the most widely used, most convenient, and, in most situations, most accurate method of measuring either exposure or absorbed dose. The ionization chamber itself is the central element in this system of dosimetry. In this chapter the principles governing the construction and operation of ionization chambers of various types are examined. Since the ionization chambers now in general use are nearly all of commercial manufacture, the emphasis is on operating characteristics and interpretation of measurements rather than on details of construction, although some knowledge of the latter is often required when applying necessary corrections to the measured quantities. Examples are given of the construction of typical chambers designed for particular purposes, and the methods of calibrating them are discussed

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...

Argus target chamber

International Nuclear Information System (INIS)

Rienecker, F. Jr.; Glaros, S.S.; Kobierecki, M.

1975-01-01

A target chamber for application in the laser fusion program must satisfy some very basic requirements. (1) Provide a vacuum on the order of 10 -6 torr. (2) Support a microscopically small target in a fixed point in space and verify its location within 5 micrometers. (3) Contain an adjustable beam focusing system capable of delivering a number of laser beams onto the target simultaneously, both in time and space. (4) Provide access for diagnostics to evaluate the results of target irradiation. (5) Have flexibility to allow changes in targets, focusing optics and number of beams. The ARGUS laser which is now under construction at LLL will have a target chamber which meets these requirements in a simple economic manner. The chamber and auxiliary equipment are described, with reference to two double beam focusing systems; namely, lenses and ellipsoidal mirrors. Provision is made for future operation with four beams, using ellipsoidal mirrors for two-sided illumination and lens systems for tetragonal and tetrahedral irradiation

Growing and analyzing biofilms in flow chambers

DEFF Research Database (Denmark)

Tolker-Nielsen, Tim; Sternberg, Claus

2011-01-01

This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic......, and disassembly and cleaning of the system. In addition, embedding and fluorescent in situ hybridization of flow chamber-grown biofilms are addressed....

HYLIFE-II tritium management system

International Nuclear Information System (INIS)

Longhurst, G.R.; Dolan, T.J.

1993-06-01

The tritium management system performs seven functions: (1) tritium gas removal from the blast chamber, (2) tritium removal from the Flibe, (3) tritium removal from helium sweep gas, (4) tritium removal from room air, (5) hydrogen isotope separation, (6) release of non-hazardous gases through the stack, (7) fixation and disposal of hazardous effluents. About 2 TBq/s (5 MCi/day) of tritium is bred in the Flibe (Li 2 BeF 4 ) molten salt coolant by neutron absorption. Tritium removal is accomplished by a two-stage vacuum disengager in each of three steam generator loops. Each stage consists of a spray of 0.4 mm diameter, hot Flibe droplets into a vacuum chamber 4 m in diameter and 7 m tall. As droplets fall downward into the vacuum, most of the tritium diffuses out and is pumped away. A fraction Φ∼10 -5 of the tritium remains in the Flibe as it leaves the second stage of the vacuum disengager, and about 24% of the remaining tritium penetrates through the steam generator tubes, per pass, so the net leakage into the steam system is about 4.7 MBq/s (11 Ci/day). The required Flibe pumping power for the vacuum disengager system is 6.6 MW. With Flibe primary coolant and a vacuum disengager, an intermediate coolant loop is not needed to prevent tritium from leaking into the steam system. An experiment is needed to demonstrate vacuum disengager operation with Flibe. A secondary containment shell with helium sweep gas captures the tritium permeating out of the Flibe ducts, limiting leaks there to about 1 Ci/day. The tritium inventory in the reactor is about 190 g, residing mostly in the large Flibe recirculation duct walls. The total cost of the tritium management system is 92 M$, of which the vacuum disengagers cost = 56%, the blast chamber vacuum system = 15%, the cryogenic plant = 9%, the emergency air cleanup and waste treatment systems each = 6%, the protium removal system = 3%, and the fuel storage system and inert gas system each = 2%

Evaluation of automatic exposure control system chamber for the dose optimization when examining pelvic in digital radiography.

Science.gov (United States)

Kim, Sung-Chul; Lee, Hae-Kag; Lee, Yang-Sub; Cho, Jae-Hwan

2015-01-01

We found a way to optimize the image quality and reduce the exposure dose of patients through the proper activity combination of the automatic exposure control system chamber for the dose optimization when examining the pelvic anteroposterior side using the phantom of the human body standard model. We set 7 combinations of the chamber of automatic exposure control system. The effective dose was yielded by measuring five times for each according to the activity combination of the chamber for the dose measurement. Five radiologists with more than five years of experience evaluated the image through picture archiving and communication system using double blind test while classifying the 6 anatomical sites into 3-point level (improper, proper, perfect). When only one central chamber was activated, the effective dose was found to be the highest level, 0.287 mSv; and lowest when only the top left chamber was used, 0.165 mSv. After the subjective evaluation by five panel members on the pelvic image was completed, there was no statistically meaningful difference between the 7 chamber combinations, and all had good image quality. When testing the pelvic anteroposterior side with digital radiography, we were able to reduce the exposure dose of patients using the combination of the top right side of or the top two of the chamber.

Gas-mixing system for drift chambers using solenoid valves

International Nuclear Information System (INIS)

Cooper, W.E.; Sugano, K.; Trentlage, D.B.

1983-04-01

We describe an inexpensive system for mixing argon and ethane drift chamber gas which is used for the E-605 experiment at Fermilab. This system is based on the idea of intermittent mixing of gases with fixed mixing flow rates. A dual-action pressure switch senses the pressure in a mixed gas reservoir tank and operates solenoid valves to control mixing action and regulate reservoir pressure. This system has the advantages that simple controls accurately regulate the mixing ratio and that the mixing ratio is nearly flow rate independent. We also report the results of the gas analysis of various samplings, and the reliability of the system in long-term running

DESIGNING HYDRAULIC AIR CHAMBER IN WATER TRANSMISSION SYSTEMS USING GENETIC ALGORITHM

Directory of Open Access Journals (Sweden)

Abdorahim Jamal

2016-09-01

Full Text Available Transient flow control in Water Transmission Systems (WTS is one of the requirements of designing these systems. Hence, among control equipment, air chambers offer the best solution to control transient flow effects, i.e. both prevents water column separation and absorbs pressure increase. It is essential to carry out an accurate and optimized design of air chambers, not only due to high costs of their manufacturing but also their important protective role. Accordingly, hydraulic design parameters comprise tank volume, diameter of nozzle and coefficients of inflow and outflow of nozzle. In this paper, it is intended to optimize these parameters in order to minimize manufacturing costs. On the other hand, maximum and minimum pressures in main pipeline are considered as constraints which shall fall in allowed range. Therefore, a model has been developed which is a combination of a hydraulic simulation model of WTS and an optimization model based on genetic algorithm. This model is first applied to WTS of Dehgolan-Ghorveh plain as a case study. Results of this research demonstrate that based on suggested model, negative wave creation and pressure increase in pipeline is prevented as well as decrease in manufacturing costs of air chamber.

Recombination chamber and a measuring system with sensitivity sufficient for in-flight and low-level dosimetry

International Nuclear Information System (INIS)

Zielczynski, M.; Golnik, N.; Shvidkij, S.V.

1996-01-01

A recombination chamber is proposed to be for determination of ambient dose equivalent, H*(10) during high-altitude flights and space missions. Polarizing electrodes of the chamber are supplied from two capacitors permanently connected to the electrodes. Ions, collected on the measuring electrode, charge a measuring capacitor that is also permanently connected to the electrode. The collected charge is proportional to H*(10), so the chamber with only three capacitors creates a whole measuring system. The special procedure was introduced for charging the supplying capacitors and for reading the voltage on the measuring capacitor. The procedure has to be performed in laboratory conditions before and after the flight. The measuring system with recombination chamber of REM-2 type allows to measure the H*(10) above 10 μSv with uncertainly ca. 25% in any field of penetration radiation, with an integration time up to some days. The system has been checked in field conditions. (author). 1 fig

Industrial defectoscope based on multiwire proportional chamber in CAMAC system

International Nuclear Information System (INIS)

Brzeski, P.; Kazubek, M.; Mirkowski, J.; Szabatin, R.

1976-01-01

The defectoscope for non-destructive testing has been built at the Institute of Radioelectronics in collaboration with the Electrotechnical Institute, Non-destructive Division. The defectoscope consists of the following parts: gamma radiation detector, multiwire proportional chamber with γ-e converter, preamplifier system attached directly to the chamber wires, logic module of CAMAC philoscopy, and MERA 300 minicomputer. The defectoscope is used to detect material flaws in tested objects, irradiated from an internal radiation source. Minicomputer used enables data processing. The data collected in mincomputer memory are the radiological image of a tested object. It is possible to display the collected image on a television monitor, to display any profile of the image on an oscilloscope, to print the map of the image on a mosaic printer. (author)

The CDF II eXtremely Fast Tracker Upgrade

CERN Document Server

Fedorko, I; Errede, D; Gerberich, H; Junk, T; Kasten, M; Levine, S; Mokos, R; Pitts, K; Rogers, E; Veramendi, G; Azzurri, P; Donati, S; Staveris-Polykalas, A; Cochran, E; Efron, J; Gartner, J; Hughes, R; Johnson, M; Kilminster, B; Lannon, K; McKim, J; Olivito, D; Parks, B; Slaunwhite, J; Winer, B; Dittmann, J; Hewamanage, S; Krumnack, N; Wilson, J S; Erbacher, R; Forrest, R; Ivanov, A; Soha, A; Flanagan, G; Jones, T; Holm, S; Klein, R; Schmidt, E E; Scott, L; Shaw, T; Wilson, P J

2008-01-01

The CDF II eXtremely Fast Tracker (XFT) is the trigger processor which reconstructs charged particle tracks in the transverse plane of the central tracking chamber. The XFT tracks are also extrapolated to the electromagnetic calorimeter and muon chambers to generate trigger electron and muon candidates. The XFT is crucial for the entire CDF II physics program: it detects high pT leptons from W/Z and heavy flavor decays and, in conjunction with the Level 2 processors, it identifies secondary vertices from beauty decays. The XFT has thus been crucial for the recent measurement of the oscilation and Σb discovery. The increase of the Tevatron instantaneous luminosity demanded an upgrade of the system to cope with the higher occupancy of the chamber. In the upgraded XFT, three dimensional tracking reduces the level of fake tracks and measures the longitudinal track parameters, which strongly reinforce the trigger selections. This allows to mantain the trigger perfectly efficient at the record luminosities 2–3·...

Performance of single chamber biocatalyzed electrolysis with different types of ion exchange membranes

NARCIS (Netherlands)

Rozendal, R.A.; Hamelers, H.V.M.; Molenkamp, R.J.; Buisman, C.J.N.

2007-01-01

In this paper hydrogen production through biocatalyzed electrolysis was studied for the first time in a single chamber configuration. Single chamber biocatalyzed electrolysis was tested in two configurations: (i) with a cation exchange membrane (CEM) and (ii) with an anion exchange membrane (AEM).

A Drift Chamber to Measure Charged Particles at COMPASS-II

Science.gov (United States)

Heitz, Robert; Compass Collaboration

2013-10-01

A new drift chamber (DC05) will be constructed to replace two tracking detector stations based on straw tubes, ST02 and ST03 in the COMPASS spectrometer. DC05 uses the designs from DC04, a previous drift chamber designed at CEA-Saclay, France, but adds the addition of more wires for improved acceptance. In addition to more wires DC05 will also change its front end electronics using a new pre-amplifier-discriminator chip (CMAD). DC05 consists of 8 layers of anode planes and 21 layers of G-10 material frames carrying cathode planes and gas windows. The wires are orientated with two layers in the vertical x-direction, two layers in the horizontal y-direction, two layers offset +10 deg of the vertical x-direction, and two layers offset -10 deg of the vertical x-direction. The wires in parallel directions are offset half a pitch to resolve left-right ambiguities. The purpose for different wire orientations is to reconstruct the 3D space particle trajectory to fit a particle track. Each layer of wires is covered on the top and bottom by a cathode plane of carbon coated mylar. All these layers are sandwiched between two steel stiffening frames for support and noise reduction. A future drift chamber, DC06, is also being designed based off of DC05. Research funded by NSF-PHY-12-05-671 Medium Energy Nuclear Physics.

A system for measuring fluxes of trace gases to and from soil and vegetation with a chamber technique

International Nuclear Information System (INIS)

Johansson, Christer; Richter, Andreas; Backlin, Leif; Granat, Lennart

1983-09-01

A mobile system for measurements of gaseous fluxes of SO 2 NO x , O 3 and water vapour between the atmosphere and the vegetation soil system using a chamber technique is described. Equipment, instruments and instrumental sensitivities are listed. A gas-handling system including calibration procedures and information on the chamber construction is also presented. With this system it is possible to make measurements using a wide range of concentrations including subambient levels. The environment in the chamber can be kept very close to ambient conditions. The mechanisms regulating the flux can be studied. A limitation of this system is the problem of extrapolating the fluxes obtained to larger areas. (author)

Fast multiwire proportional chamber data encoding system for proton tomography

International Nuclear Information System (INIS)

Brown, D.

1979-01-01

A data encoding system that rapidly generates the binary address of an active wire in a 512-wire multiwire proportional chamber has been developed. It can accept a second event on a different wire after a deadtime of 130 ns. The system incorporates preprocessing of the wire data to reject events that would require more than one wire address. It also includes a first-in, first-out memory to buffer the data flow

Electronic system for the automation of current measurements produced by ionization chambers

International Nuclear Information System (INIS)

Brancaccio, Franco; Dias, Mauro da Silva

2002-01-01

Ionization Chambers in current mode operation are usually used in Nuclear Metrology in the determination of radionuclide activity. For this purpose measurements of very low ionization currents, in the range of 10 -8 to 10 -14 A, are required. Usually, electrometers perform the current integration method under command of signals from an automation system, in order to reduce the measurement uncertainties. In the present work, an automation system, developed for current integration measurements at the Laboratorio de Metrologia Nuclear (LMN) of Instituto de Pesquisas Energeticas e Nucleares (IPEN), is described. This automation system is composed by software (graphic interface and control) and an electronic module connected to a microcomputer, by means of a commercial data acquisition card CAD12/32 (LYNX Tecnologia Eletronica Ltda.). Measurements, using an electrometer Keithley 616 (Keithley Instruments, Inc) and an ionization chamber IG12/A20 (20 th Century Electronics Ltd.), were performed in order to check the system and for validating the project. (author)

Design of creep machine and creep specimen chamber for carrying out creep tests in flowing liquid sodium

Energy Technology Data Exchange (ETDEWEB)

Ravi, S., E-mail: sravi@igcar.gov.in; Laha, K.; Sakthy, S.; Mathew, M.D.; Jayakumar, T.

2014-02-15

Highlights: • Design of a lever type creep machine for carrying out creep test in flowing sodium. • Leveling of lever during creep was achieved by automated movement of fulcrum. • Design of creep chamber for providing constant sodium flow rate across creep specimen. • Minimum use of bellow in chamber for sodium containment and mechanical isolation. • Mini-lever mechanism to counter balance load reduction on specimen due to bellow stiffness. - Abstract: A creep testing system has been designed, fabricated, installed and validated for carrying out creep tests in flowing liquid sodium. The testing system consists of two sections namely creep testing machine and an environmental chamber. The testing system has the ability of (i) applying tensile load to the test specimen through a lever, (ii) monitoring continuously the creep elongation and (iii) allowing sodium to flow around the creep specimen at constant velocity. The annular space between the creep specimen and the environmental chamber has been suitably designed to maintain constant sodium flow velocity. Primary and secondary bellows are employed in the environmental chamber to (i) mechanically isolate the creep specimen, (ii) prevent the flowing sodium in contact with air and (iii) maintain an argon gas cover to the leaking sodium if any from primary bellow, with a provision to an alarm get activated by a spark plug. The lever-horizontality during creep test has been maintained by automatically lifting up the fulcrum instead of lowering down the pull rod as conventionally used. A mini lever mechanism has been incorporated in the load train to counter balance the load reduction on specimen from the changing stiffness of the bellows. The validation of the testing system has been established by carrying out creep tests on 316L(N) stainless steel at 873 K over a wide stress range and comparing the results with those obtained in air by employing the developed and conventional creep testing machines.

Criteria for controlled atmosphere chambers

International Nuclear Information System (INIS)

Robinson, J.N.

1980-03-01

The criteria for design, construction, and operation of controlled atmosphere chambers intended for service at ORNL are presented. Classification of chambers, materials for construction, design criteria, design, controlled atmosphere chamber systems, and operating procedures are presented. ORNL Safety Manual Procedure 2.1; ORNL Health Physics Procedure Manual Appendix A-7; and Design of Viewing Windows are included in 3 appendices

A SIMPLE Bubble Chamber for Dark Matter Searches: Testing and Development

Energy Technology Data Exchange (ETDEWEB)

Ramos, A.R.; Fernandes, A.C.; Marques, J.G.; Kling, A. [C2TN, Instituto Superior Tecnico, Universidade de Lisboa, E.N. 10 - km 139.7, 2695-066 Bobadela, LRS (Portugal); Felizardo, M.; Girard, T.A. [Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003, Lisbon (Portugal); Lazaro, I. [Laboratoire Souterrain a Bas Bruit, UMS 3538 UNS/UAPV/CNRS, 84400 Rustrel-Pays d' Apt (France); Puibasset, J. [Centre de Recherche sur la Matiere Divisee CNRS et Universite d' Orleans, 45071 Orleans, 02 (France)

2015-07-01

SIMPLE (Superheated Instrument for Massive Particle Experiments) is one of only three experiments worldwide in search of evidence of astroparticle dark matter (WIMPs) using halocarbon-loaded superheated liquid (SHL) detectors. The 2012 Phase II SIMPLE measurements yielded the most restrictive exclusion contour in the spin-dependent (SD) sector of WIMP-proton interactions from a direct search experiment at the time, overlapping for the first time results previously obtained only indirectly [1]. In order to remain competitive with other experiments in the field, the next phase measurement requires larger exposure over shorter observation times with significantly improved neutron shielding. To increase exposure, SIMPLE plans, as a first step, to replace its superheated droplet detectors (SDDs), each containing an active mass of about 15 g of halocarbon, with bubble chambers capable of holding up to 20 kg of active halocarbon mass. We report on the development of the first 1 kg halocarbon SIMPLE bubble chamber prototype, including chamber recompression system design and testing and initial acoustic detection of bubble formation. (authors)

Performance Analysis of a Solar Dryer Equipped with a Recycling Air System and Desiccant Chamber

Directory of Open Access Journals (Sweden)

M.H Aghkhani

2013-09-01

Full Text Available Drying is a high energy consuming process. Solar drying is one of the most popular methods for dehydration of agricultural products. In the present study, the performance of a forced convection solar dryer equipped with recycling air system and desiccant chamber was investigated. The solar dryer is comprised of solar collector, drying chamber, silica jell desiccant chamber, air ducts, fan and measuring and controlling system. Drying rate and energy consumption in three levels of air temperature (40, 45 and 50 oC and two modes of drying (with recycling air and no-recycling with open duct system were measured and compared. The results showed that increasing the drying air temperature decreased the drying time and increased the energy consumption in the mode of non-recycling air system. The dryer efficiency and drying rate were better in the mode of recycling air system than open duct system. The highest dryer efficiency was obtained from drying air temperature of 50 oC and the mode of recycling air system. In general, the efficiency of solar collector and the highest efficiency of the dryer were 0.34 and 0.41, respectively.

20 K Helium Refrigeration System for NASA-JSC Chamber-A

Science.gov (United States)

Homan, J.; Redman, R.; Ganni, V.; Sidi-Yekhelef, A.; Knudsen, P.; Norton, R.; Lauterbach, J.; Linza, R.; Vargas, G.

2013-01-01

A new 20 K helium refrigerator installed at NASA Johnson Space Center's Space Environment Simulation Laboratory (SESL) was successfully commissioned and tested in 2012. The refrigerator is used to create a deep space environment within SESL s Chamber A to perform ground testing of the James Webb Space Telescope. The chamber previously and currently still has helium cryopumping panels (CPP) and LN2 shrouds used to create Low Earth Orbit environments. Now with the new refrigerator and new helium shrouds (45 x 65 ) the chamber can create a deep space environment. The process design, system analysis, specification development, and commissioning oversight were performed by the cryogenics department at Jefferson Labs, while the contracts and system installation was performed by the ESC group at JSC. Commissioning data indicate a inverse coefficient of performance better than 70 W/W for a 18 KW load at 20 K (accounting for liquid nitrogen precooling power) that remains essentially constant down to 1/3 of this load. Even at 10 percent of the maximum capacity, the performance is better than 140 W/W at 20K. The refrigerator exceeded all design goals and demonstrated the ability to support a wide load range from 10kW at 15 K to 100 kW at 100K. The refrigerator is capable of operating at any load temperature from 15K to ambient with tight temperature stability. The new shroud (36 tons of aluminum) can be cooled from room temperature to 20 K in 24 hours. This paper will outline the process design and commissioning results.

Tests of the data acquisition system and detector control system for the muon chambers of the CMS experiment at the LHC

International Nuclear Information System (INIS)

Sowa, Michael Christian

2009-01-01

The Phys. Inst. III A of RWTH Aachen University is involved in the development, production and tests of the Drift Tube (DT) muon chambers for the barrel muon system of the CMS detector at the LHC at CERN (Geneva). The present thesis describes some test procedures which were developed and performed for the chamber local Data Acquisition (DAQ) system, as well as for parts of the Detector Control System (DCS). The test results were analyzed and discussed. Two main kinds of DAQ tests were done. On the one hand, to compare two different DAQ systems, the chamber signals were split and read out by both systems. This method allowed to validate them by demonstrating, that there were no relevant differences in the measured drift times, generated by the same muon event in the same chamber cells. On the other hand, after the systems were validated, the quality of the data was checked. For this purpose extensive noise studies were performed. The noise dependence on various parameters (threshold,HV) was investigated quantitatively. Also detailed studies on single cells, qualified as ''dead'' and ''noisy'' were done. For the DAQ tests a flexible hardware and software environment was needed. The organization and installation of the supplied electronics, as well as the software development was realized within the scope of this thesis. The DCS tests were focused on the local gas pressure read-out components, attached directly to the chamber: pressure sensor, manifolds and the pressure ADC (PADC). At first it was crucial to proof, that the calibration of the mentioned chamber components for the gas pressure measurement is valid. The sensor calibration data were checked and possible differences in their response to the same pressure were studied. The analysis of the results indicated that the sensor output depends also on the ambient temperature, a new experience which implied an additional pedestal measurement of the chamber gas pressure sensors at CMS. The second test sequence

Tests of the data acquisition system and detector control system for the muon chambers of the CMS experiment at the LHC

Energy Technology Data Exchange (ETDEWEB)

Sowa, Michael Christian

2009-02-27

The Phys. Inst. III A of RWTH Aachen University is involved in the development, production and tests of the Drift Tube (DT) muon chambers for the barrel muon system of the CMS detector at the LHC at CERN (Geneva). The present thesis describes some test procedures which were developed and performed for the chamber local Data Acquisition (DAQ) system, as well as for parts of the Detector Control System (DCS). The test results were analyzed and discussed. Two main kinds of DAQ tests were done. On the one hand, to compare two different DAQ systems, the chamber signals were split and read out by both systems. This method allowed to validate them by demonstrating, that there were no relevant differences in the measured drift times, generated by the same muon event in the same chamber cells. On the other hand, after the systems were validated, the quality of the data was checked. For this purpose extensive noise studies were performed. The noise dependence on various parameters (threshold,HV) was investigated quantitatively. Also detailed studies on single cells, qualified as ''dead'' and ''noisy'' were done. For the DAQ tests a flexible hardware and software environment was needed. The organization and installation of the supplied electronics, as well as the software development was realized within the scope of this thesis. The DCS tests were focused on the local gas pressure read-out components, attached directly to the chamber: pressure sensor, manifolds and the pressure ADC (PADC). At first it was crucial to proof, that the calibration of the mentioned chamber components for the gas pressure measurement is valid. The sensor calibration data were checked and possible differences in their response to the same pressure were studied. The analysis of the results indicated that the sensor output depends also on the ambient temperature, a new experience which implied an additional pedestal measurement of the chamber gas pressure

A combination drift chamber/pad chamber for very high readout rates

International Nuclear Information System (INIS)

Spiegel, L.; Cataldi, G.; Elia, V.; Mazur, P.; Murphy, C.T.; Smith, R.P.; Yang, W.; Alexopoulos, T.; Durandet, C.; Erwin, A.; Jennings, J.; Antoniazzi, L.; Introzzi, G.; Lanza, A.; Liguori, G.; Torre, P.; Arenton, M.; Conetti, S.; Cox, B.; Dukes, E.; Golovatyuk, V.; Hanlet, P.; McManus, A.; Nelson, K.; Recagni, M.; Segal, J.; Sun, J.; Ballagh, C.; Bingham, H.; Kaeding, T.; Lys, J.; Misawa, S.; Blankman, A.; Borodin, S.; Kononenko, W.; Newcomer, M.; Selove, W.; Trojak, T.; VanBerg, R.; Zhang, S.N.; Block, M.; Corti, G.; LeCompte, T.; Rosen, J.; Yao, T.; Boden, A.; Cline, D.; Ramachandran, S.; Rhoades, J.; Tokar, S.; Budagov, J.; Tsyganov, E.; Cao, Z.L.; He, M.; Wang, C.; Wei, C.; Zhang, N.; Chen, T.Y.; Yao, N.; Clark, K.; Jenkins, M.; Cooper, M.; Creti, P.; Gorini, E.; Grancagnolo, F.; Panareo, M.; Fortney, L.; Kowald, W.; Haire, M.; Judd, D.; Turnbull, L.; Wagoner, D.; Lau, K.; Mo, G.; Trischuk, J.

1991-11-01

Six medium-sized (∼1 x 2 m 2 ) drift chambers with pad and stripe readout have been constructed for and are presently operating in Fermi National Accelerator Laboratory experiment E-771. Each chamber module actually represents a pair of identical planes: two sets of anode wires, two sets of stripes, and two sets of pads. The wire planes are read out separately and represent X measurements in the coordinate system of the experiment. The twin stripe and pad planes are internally paired within the chamber modules; stripe signals represent Y measurements and pad signals combination X and Y measurements. Signals which develop on the stripes and pads are mirror (but inverted) images of what is seen on the wires. In addition to being used in the off-line pattern recognition, pad signals are also used as inputs to an on-line high transverse momentum (pt) trigger processor. While the techniques involved in the design and construction of the chambers are not novel, they may be of interest to experiments contemplating very large area, high rate chambers for future spectrometers

A combination drift chamber/pad chamber for very high readout rates

Energy Technology Data Exchange (ETDEWEB)

Spiegel, L.; Cataldi, G.; Elia, V.; Mazur, P.; Murphy, C.T.; Smith, R.P.; Yang, W. (Fermi National Accelerator Lab., Batavia, IL (United States)); Alexopoulos, T.; Durandet, C.; Erwin, A.; Jennings, J. (Wisconsin Univ., Madison, WI (United States)); Antoniazzi, L.; Introzzi, G.; Lanza, A.; Liguori, G.; Torre, P. (Pavia Univ. (Italy) Istituto Nazionale di Fisica Nucleare, Rome (Italy)); Arenton, M.; Conetti, S.

1991-11-01

Six medium-sized ({approx}1 {times} 2 m{sup 2}) drift chambers with pad and stripe readout have been constructed for and are presently operating in Fermi National Accelerator Laboratory experiment E-771. Each chamber module actually represents a pair of identical planes: two sets of anode wires, two sets of stripes, and two sets of pads. The wire planes are read out separately and represent X measurements in the coordinate system of the experiment. The twin stripe and pad planes are internally paired within the chamber modules; stripe signals represent Y measurements and pad signals combination X and Y measurements. Signals which develop on the stripes and pads are mirror (but inverted) images of what is seen on the wires. In addition to being used in the off-line pattern recognition, pad signals are also used as inputs to an on-line high transverse momentum (pt) trigger processor. While the techniques involved in the design and construction of the chambers are not novel, they may be of interest to experiments contemplating very large area, high rate chambers for future spectrometers.

PBFA II energy storage section design

International Nuclear Information System (INIS)

Wilson, J.M.

1983-01-01

PBFA II will be the second thirty-six module accelerator built at Sandia National Laboratories for particle beam fusion feasibility studies. Each module of the machine will deliver 2.8 terawatts to a central experimental chamber. The total power delivered (100 terawatts) is expected to permit ignition scaling studies beginning in 1986. The PBFA II energy storage system consists of thirty-six 6.0 mv, 400 kj. Marx generators with their high voltage trigger and charging systems, and electromechanical output switching system. The paper describes the current design of this section of the machine. Constraints imposed by the existing tank and building are presented, as they relate to locating support systems in the oil section of PBFA II. The charging system and output switches have been designed and are described. A conceptual design for the Marx triggering system is also presented. Additional hardware (monitors, grounding connections, etc.) is discussed briefly with design details given where available

Study on the stability of waterpower-speed control system for hydropower station with air cushion surge chamber

International Nuclear Information System (INIS)

Guo, W C; Yang, J D; Chen, J P; Teng, Y

2014-01-01

According to the fact that the effects of penstock, unit and governor on stability of water level fluctuation for hydropower station with air cushion surge chamber are neglected in previous researches, in this paper, Thoma assumption is broken through, the complete mathematical model of waterpower-speed control system for hydropower station with air cushion surge chamber is established, and the comprehensive transfer function and linear homogeneous differential equation that characterize the dynamic characteristics of system are derived. The stability domain that characterizes the good or bad of stability quantitatively is drawn by using the stability conditions. The effects of the fluid inertia in water diversion system, the air cushion surge chamber parameters, hydraulic turbine characteristics, generator characteristics, and regulation modes of governor on the stability of waterpower-speed control system are analyzed through stability domain. The main conclusions are as follows: The fluid inertia in water diversion system and hydraulic turbine characteristics have unfavorable effects on the system while generator characteristics have favorable effect. The stability keeps getting better with the increase of chamber height and basal area and the decrease of air pressure and air polytropic exponent. The stability of power regulation mode is obviously better than that of frequency regulation mode

Drift chamber vertex detectors for SLC/LEP

International Nuclear Information System (INIS)

Hayes, K.G.

1987-03-01

The short but measurable lifetimes of the b and c quarks and the tau lepton have motivated the development of high precision tracking detectors capable of providing information on the decay vertex topology of events containing these particles. This paper reviews the OPAL, L3, and MARK II experiments vertex drift chambers

Tokamak Fusion Test Reactor neutral beam injection system vacuum chamber

International Nuclear Information System (INIS)

Pedrotti, L.R.

1977-01-01

Most of the components of the Neutral Beam Lines of the Tokamak Fusion Test Reactor (TFTR) will be enclosed in a 50 cubic meter box-shaped vacuum chamber. The chamber will have a number of unorthodox features to accomodate both neutral beam and TFTR requirements. The design constraints, and the resulting chamber design, are presented

Whole System Carbon Exchange of Small Stands of Pinus Ponderosa Growing at Different CO(sub 2) concentrations in open top chambers; FINAL

International Nuclear Information System (INIS)

Ball, J. Timothy; Ross, Peter D.; Picone, John B.; Eichelmann, Hillar Y.; Ross, Gregory N.

1996-01-01

Functional understanding of the carbon cycle from the molecular to the global level is a high scientific priority requiring explanation of the relationship between fluxes at different spatial and temporal scales. We describe methods used to convert an open top chamber into both closed and open flow gas exchange systems utilized to measure such fluxes. The systems described consist of temporary modifications to an open top chamber, and are put in place for several days on one or several open top chambers. In the closed system approach, a chamber is quickly sealed for a short, predetermined time interval, the change in gas concentrations is measured, then the chamber is unsealed and ventilated. In the open flow system approach, airflow into the open top chamber is measured by trace gas injection, and the air stream concentration of CO(sub 2) and water vapor is measured before and after injection into the chamber. The closed chamber approach can resolve smaller fluxes, but causes transient increases in chamber air temperature, and has a high labor requirement. The open flow approach reduces the deviation of measuring conditions from ambient, may be semi-automated (requiring less labor), allows a more frequent sampling interval, but cannot resolve low fluxes well. Data demonstrating the capabilities of these systems show that, in open canopies of ponderosa pine, scaling fluxes from leaves to whole canopies is well approximated from summation of leaf P(sub s) rates. Flux measurements obtained from these systems can be a valuable contribution to our understanding whole system material fluxes, and challenge our understanding of ecosystem carbon budgets

Lightweight Ultrahigh Temperature CMC-Lined C/C Combustion Chambers, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — NASA and DoD are seeking high-performance, lightweight liquid rocket combustion chambers with future performance goals that cannot be achieved using state-of-the-art...

THE LIQUID NITROGEN SYSTEM FOR CHAMBER A; A CHANGE FROM ORIGINAL FORCED FLOW DESIGN TO A NATURAL FLOW (THERMO SIPHON) SYSTEM

International Nuclear Information System (INIS)

Homan, J.; Montz, M.; Ganni, V.; Sidi-Yekhlef, A.; Knudsen, P.; Creel, J.; Arenius, D.; Garcia, S.

2010-01-01

NASA at the Johnson Space Center (JSC) in Houston is presently working toward modifying the original forced flow liquid nitrogen cooling system for the thermal shield in the space simulation chamber-A in Building 32 to work as a natural flow (thermo siphon) system. Chamber A is 19.8 m (65 ft) in diameter and 35.66 m (117 ft) high. The LN 2 shroud environment within the chamber is approximately 17.4 m (57 ft) in diameter and 28 m (92 ft) high. The new thermo siphon system will improve the reliability, stability of the system. Also it will reduce the operating temperature and the liquid nitrogen use to operate the system. This paper will present the requirements for the various operating modes. System level thermodynamic comparisons of the existing system to the various options studied and the final option selected will be outlined. A thermal and hydraulic analysis to validate the selected option for the conversion of the current forced flow to natural flow design will be discussed. The proposed modifications to existing system to convert to natural circulation (thermo siphon) system and the design features to help improve the operations, and maintenance of the system will be presented.

A data acquisition system intended for on-line analusis of the pictures from large bubble chambers

International Nuclear Information System (INIS)

Antoni, F.; Aria, E.; Baumgarten, R.; Berges, G.; Blanc, F.; Christophel, E.; Engel, J.P.; Graup, J.P.; Guyonnet, J.L.; Hauer, G.; Jaeg, R.; Kapps, E.; Lloret, A.; Lott, F.; Marsaudon, J.C.; Oswald, R.; Persigny, J.; Priss, R.; Schuster, G.; Unamuno, S. de; Volmer, P.

1977-01-01

The system of analysis of large bubble chamber pictures, such as from Gargamelle, BEBC, realized in the heavy liquid bubble chamber group with scanning and measurements stations on-line with a CDC 1700 computer is presented. The general characteristics of these stations and of the computer are discussed and emphasis is put on the conception and functions of the analysis programmes: scanning, measurement and data processing. The data acquisition system runs in a context of real time multiprogrammation [fr

Optical design of a reaction chamber for weakly absorbed light. II. Parallel mirrors, multitravel

International Nuclear Information System (INIS)

Devaney, J.J.; Finch, F.T.

1975-06-01

This report outlines the possibilities to be found using one or more diffraction-limited high-quality light beams to activate a weakly absorbing gas in a regime where the diffraction spread can be controlled by converging optical devices to within a ratio of √2 of the minimum at the beam waist (corresponding lengths between converging elements are within twice the Rayleigh range). Our designs use plane or cylindrical parallel mirrors down which a light beam is repeatedly reflected. In the first design variation, the beam is re-reflected up the parallel mirrors to the entrance aperture where it can be returned repeatedly for a number of multiply reflecting ''travels'' up and down the parallel mirror reaction chamber. In the second variation, the return of the beam after each multiply reflecting ''travel'' down the chamber is external to the chamber and is achieved by two mirror reflections. For diffraction control the return mirrors can be made converging. For multiple laser excitation, any of the external return mirrors can be replaced by a laser. The advantage of these designs is a high degree of uniformity of chamber illumination with a reasonably high number of passes. Drawbacks of the designs are the large space needed for beam return (many tens of meters for some parameters) and (common to all high optical quality chambers) the figuring and reflectivity demands on the mirrors. (U.S.)

Study of a proportional chamber for the detection of muons in the CELLO experiment

International Nuclear Information System (INIS)

Durand, Alain.

1978-01-01

The physics of e + e - interactions that the CELLO experiment is proposing to do requires good μ detection. For this, the prototype of a wire type proportional chamber with integrated logical system read-out is under study. The various phenomena that govern the working of a wire type proportional chamber are recalled first of all. Section II deals with the various working and read-out modes. Section III is devoted to the description of the method chosen and its advantages. In Sections IV and V, the two more specifically studied read-out methods are presented and it is shown that the read-out method by delay line proves to be much more delicate to use than the integrated electronic method finally selected [fr

An automatic control of the pumping system for the vacuum chamber of the cyclotron

International Nuclear Information System (INIS)

Ikegami, Kumio; Kageyama, Tadashi; Kohno, Isao

1979-01-01

The main pumping system of the 160 cm cyclotron is composed of 32'', 14'', and 6'' oil difusion pumps connected in series and rough pumping system which consists of 1500 l/min rotary pump and 300 m 3 /h roots pump with 650 l/min rotary backing pump. Instead of manual operation an automatic control devise of the pumping system was developed and many valves were replaced with pneumatic ones. In the new control system, pumps and valves are operated automatically, according to the indication of pirani detectors, to evacuate the chamber of the cyclotron up to the pressure of 0.7 - 1.0 x 10 -6 Torr, and also to protect the pumping system against vacuum failure by accidental leakage in the chamber. The graphic handling board of the pumping system is installed on the control panel and each switch is provided with a name card showing its function briefly. (author)

Integrated Procurement Management System, Version II

Science.gov (United States)

Collier, L. J.

1985-01-01

Integrated Procurement Management System, Version II (IPMS II) is online/ batch system for collecting developing, managing and disseminating procurementrelated data at NASA Johnson Space Center. Portions of IPMS II adaptable to other procurement situations.

Multiwire proportional chambers in the triggering system of the streamer chamber for high-Pt charged particle production detection in 40 GeV/c hadron-nucleus interactions

International Nuclear Information System (INIS)

Czyrkowski, H.; Dabrowski, R.; Derlicki, A.

1985-01-01

We describe a triggering system based on the multiwire proportional chambers (MWPCs) for the high-P t charged particles selection in Π - A interactions at 40 GeV/c (RISC experiment). The coincidence matrices processing only combinations of hits in MWPCs allow one to reach sufficient purity of experimental material. The large area MWPCs work close to the streamer chamber high voltage electrode without any problems. Details of the fabrication procedure and peformances are also given. 12 refs. (author)

Aligning the CMS Muon Chambers with the Muon Alignment System during an Extended Cosmic Ray Run

CERN Document Server

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Yoo, H D; Zheng, Y; Jindal, P; Parashar, N; Cuplov, V; Ecklund, K M; Geurts, F J M; Liu, J H; Maronde, D; Matveev, M; Padley, B P; Redjimi, R; Roberts, J; Sabbatini, L; Tumanov, A; Betchart, B; Bodek, A; Budd, H; Chung, Y S; de Barbaro, P; Demina, R; Flacher, H; Gotra, Y; Harel, A; Korjenevski, S; Miner, D C; Orbaker, D; Petrillo, G; Vishnevskiy, D; Zielinski, M; Bhatti, A; Demortier, L; Goulianos, K; Hatakeyama, K; Lungu, G; Mesropian, C; Yan, M; Atramentov, O; Bartz, E; Gershtein, Y; Halkiadakis, E; Hits, D; Lath, A; Rose, K; Schnetzer, S; Somalwar, S; Stone, R; Thomas, S; Watts, T L; Cerizza, G; Hollingsworth, M; Spanier, S; Yang, Z C; York, A; Asaadi, J; Aurisano, A; Eusebi, R; Golyash, A; Gurrola, A; Kamon, T; Nguyen, C N; Pivarski, J; Safonov, A; Sengupta, S; Toback, D; Weinberger, M; Akchurin, N; Berntzon, L; Gumus, K; Jeong, C; Kim, H; Lee, S W; Popescu, S; Roh, Y; Sill, A; Volobouev, I; Washington, E; Wigmans, R; Yazgan, E; Engh, D; Florez, C; Johns, W; Pathak, S; Sheldon, P; Andelin, D; Arenton, M W; Balazs, M; Boutle, S; Buehler, M; Conetti, S; Cox, B; Hirosky, R; Ledovskoy, A; Neu, C; Phillips II, D; Ronquest, M; Yohay, R; Gollapinni, S; Gunthoti, K; Harr, R; Karchin, P E; Mattson, M; Sakharov, A; Anderson, M; Bachtis, M; Bellinger, J N; Carlsmith, D; Crotty, I; Dasu, S; Dutta, S; Efron, J; Feyzi, F; Flood, K; Gray, L; Grogg, K S; Grothe, M; Hall-Wilton, R; Jaworski, M; Klabbers, P; Klukas, J; Lanaro, A; Lazaridis, C; Leonard, J; Loveless, R; Magrans de Abril, M; Mohapatra, A; Ott, G; Polese, G; Reeder, D; Savin, A; Smith, W H; Sourkov, A; Swanson, J; Weinberg, M; Wenman, D; Wensveen, M; White, A

2010-01-01

The alignment system for the muon spectrometer of the CMS detector comprises three independent subsystems of optical and analog position sensors. It aligns muon chambers with respect to each other and to the central silicon tracker. System commissioning at full magnetic field began in 2008 during an extended cosmic ray run. The system succeeded in tracking muon detector movements of up to 18 mm and rotations of several milliradians under magnetic forces. Depending on coordinate and subsystem, the system achieved chamber alignment precisions of 140-350 microns and 30-200 microradians. Systematic errors on displacements are estimated to be 340-590 microns based on comparisons with independent photogrammetry measurements.

Temperature Studies for ATLAS MDT BOS Chambers

CERN Document Server

Engl, A.; Biebel, O.; Mameghani, R.; Merkl, D.; Rauscher, F.; Schaile, D.; Ströhmer, R.

Data sets with high statistics taken at the cosmic ray facility, equipped with 3 ATLAS BOS MDT chambers, in Garching (Munich) have been used to study temperature and pressure effects on gas gain and drifttime. The deformation of a thermally expanded chamber was reconstructed using the internal RasNik alignment monitoring system and the tracks from cosmic data. For these studies a heating system was designed to increase the temperature of the middle chamber by up to 20 Kelvins over room temperature. For comparison the temperature effects on gas properties have been simulated with Garfield. The maximum drifttime decreased under temperature raise by -2.21 +- 0.08 ns/K, in agreement with the results of pressure variations and the Garfield simulation. The increased temperatures led to a linear increase of the gas gain of about 2.1% 1/K. The chamber deformation has been analyzed with the help of reconstructed tracks. By the comparison of the tracks through the reference chambers with these through the test chamber ...

Tailored vacuum chambers for ac magnets

International Nuclear Information System (INIS)

Harvey, A.

1985-01-01

The proposed LAMPF-II accelerator has a 60-Hz booster synchrotron and a 3-Hz main ring. To provide a vacuum enclosure inside the magnets with low eddy-current losses and minimal field distortion, yet capable of carrying rf image currents and providing beam stabilization, we propose an innovative combination pipe. Structurally, the enclosure is high-purity alumina ceramic, which is strong, radiation resistant, and has good vacuum properties. Applied to the chamber are thin, spaced, silver conductors using adapted thick-film technology. The conductor design can be tailored to the stabilization requirements, for example, longitudinal conductors for image currents, circumferential for transverse stabilization. The inside of the chamber has a thin, resistive coating to avoid charge build-up. The overall 60-Hz power loss is less than 100 W/m

Calibration and consistency of results of an ionization-chamber secondary standard measuring system for activity

International Nuclear Information System (INIS)

Schrader, Heinrich

2000-01-01

Calibration in terms of activity of the ionization-chamber secondary standard measuring systems at the PTB is described. The measurement results of a Centronic IG12/A20, a Vinten ISOCAL IV and a radionuclide calibrator chamber for nuclear medicine applications are discussed, their energy-dependent efficiency curves established and the consistency checked using recently evaluated radionuclide decay data. Criteria for evaluating and transferring calibration factors (or efficiencies) are given

A drift chamber system for a toroidal detector

International Nuclear Information System (INIS)

Barbosa, F.J.; Christo, S.; Cuevas, C.; Doolittle, G.; Doughty, D.C.; Hutton, C.; Joyce, D.; Mecking, B.A.; Mestayer, M.D.; Niczyporuk, B.; O'Meara, J.E.; Tilles, D.; Tuzel, W.; Yegneswaran, A.

1992-01-01

We present design details for drift chambers to be used in the CLAS detector at CEBAF. Novel features include nonparallel endplates fabricated from composite materials, a gas mixture which includes helium to reduce multiple scattering, low wire tension, and a hexagonal cell layout. Magnetic field strength in the active region ranges from 0 to 2 T, and wire length varies from 10 to 300 cm. We discuss specific construction details for the outer drift chambers. (orig.)

A drift chamber system for a toroidal detector

Energy Technology Data Exchange (ETDEWEB)

Barbosa, F.J.; Christo, S.; Cuevas, C.; Doolittle, G.; Doughty, D.C.; Hutton, C.; Joyce, D.; Mecking, B.A.; Mestayer, M.D.; Niczyporuk, B.; O' Meara, J.E.; Tilles, D.; Tuzel, W.; Yegneswaran, A. (CEBAF, Newport News, VA (United States))

1992-12-01

We present design details for drift chambers to be used in the CLAS detector at CEBAF. Novel features include nonparallel endplates fabricated from composite materials, a gas mixture which includes helium to reduce multiple scattering, low wire tension, and a hexagonal cell layout. Magnetic field strength in the active region ranges from 0 to 2 T, and wire length varies from 10 to 300 cm. We discuss specific construction details for the outer drift chambers. (orig.).

NSLS-II Radio Frequency Systems

Energy Technology Data Exchange (ETDEWEB)

Rose J.; Gao F.; Goel, A.; Holub, B.; Kulpin, J.; Marques, C.; Yeddulla, M.

2015-05-03

The National Synchrotron Light Source II is a 3 GeV X-ray user facility commissioned in 2014. The NSLS-II RF system consists of the master oscillator, digital low level RF controllers, linac, booster and storage ring RF sub-systems, as well as a supporting cryogenic system. Here we will report on RF commissioning and early operation experience of the system.

An innovative system for supplying air and fuel mixture to a combustion chamber of an engine

Science.gov (United States)

Saikumar, G. R. Bharath

2018-04-01

Conventional carburetors are being used since decades to ensure that the desired ratio of air and fuel enters the combustion chamber for combustion for the purpose of generating power in an Spark Ignition(SI) internal combustion engine. However to increase the efficiency, the carburetor system is gradually being replaced by fuel injection systems. Fuel injection systems use injectors to supply pressurized fuel into the combustion chamber. Owing to the high initial and maintenance cost, carburetors are still ruling in the low cost vehicle domain. An innovative concept is conceived, which is an alternative method to the carburetor system to supply the air and fuel mixture to a combustion chamber of an engine. This system comprises of an inner hollow cylinder with minute holes drilled along its length with an outer cylinder capable of sliding along its length or its longitudinal axis. This system is placed in the venturi instead of the conventional carburetor system. Fuel enters from the bottom inlet of the inner cylinder and flows out through the holes provided along its length. The fuel flow from the inner cylinder is dependent on the size and the number of holes exposed at that instance by the sliding outer cylinder which in turn is connected to the throttle or accelerator.

AUTOMATIC CONTROL SYSTEM FOR REGULATED HIGH TEMPERATURE MAIN COMBUSTION CHAMBER OF MANEUVERABLE AIRCRAFT MULTIMODE GAS TURBINE ENGINE

Directory of Open Access Journals (Sweden)

T. V. Gras’Ko

2014-01-01

Full Text Available The paper describes choosing and substantiating the control laws, forming the appearance the automatic control system for regulated high temperature main combustion chamber of maneuverable aircraft multimode gas turbine engine aimed at sustainable and effective functioning of main combustion chamber within a broad operation range.

Track photographing in 8-m streamer chamber

International Nuclear Information System (INIS)

Anisimova, N.Z.; Davidenko, V.A.; Kantserov, V.A.; Rybakov, V.G.; Somov, S.V.

1981-01-01

A system for obtaining data from a streamer chamber intended for measuring muon polarization is described. An optical scheme for photographing of tracks in the chamber is given. The photographing process is complicated at the expense of large dimensions and module structure of the chamber as well as due to insufficient for direct photographing brightness of streamers. The system described was tested during a long time in a physical experiment. More than 100 thousand photos have been taken by its means [ru

Combined effect of upstream surge chamber and sloping ceiling tailrace tunnel on dynamic performance of turbine regulating system of hydroelectric power plant

International Nuclear Information System (INIS)

Guo, Wencheng; Yang, Jiandong

2017-01-01

Highlights: • Nonlinear mathematical model and Hopf bifurcation analysis of turbine regulating system are presented. • Dynamic performance of turbine regulating system under 0.5 times Thoma sectional area is analyzed and a novel dynamic performance is revealed. • Relationship between two bifurcation lines and wave superposition is studied. • Combined effect mechanisms of upstream surge chamber and sloping ceiling tailrace tunnel on stability are revealed and optimization methods are proposed. - Abstract: Based on the nonlinear mathematical model of the turbine regulating system of hydroelectric power plant with upstream surge chamber and sloping ceiling tailrace tunnel and the Hopf bifurcation theory, this paper firstly studies the dynamic performance of the turbine regulating system under 0.5 times Thoma sectional area of surge chamber, and reveals a novel dynamic performance. Then, the relationship between the two bifurcation lines and the wave superposition of upstream surge chamber and sloping ceiling tailrace tunnel is analyzed. Finally, the effect mechanisms of the wave superposition on the system stability are investigated, and the methods to improve the system stability are proposed. The results indicate that: Under the combined effect of upstream surge chamber and sloping ceiling tailrace tunnel, the dynamic performance of the turbine regulating system of hydroelectric power plant shows an obvious difference on the two sides of the critical sectional area of surge chamber. There are two bifurcation lines for the condition of 0.5 times Thoma sectional area, i.e. Bifurcation line 1 and Bifurcation line 2, which represent the stability characteristics of the flow oscillation of “penstock-sloping ceiling tailrace tunnel” and the water-level fluctuation in upstream surge chamber, respectively. The stable domain of the system is determined by Bifurcation line 2. The effect of upstream surge chamber mainly depends on its sectional area, while the

Commissioning of the Liquid Nitrogen Thermo-Siphon System for NASA-JSC Chamber-A

Science.gov (United States)

Homan, J.; Montz, M.; Ganni, V.; Sidi-Yekhlef, A.; Knudsen, P.; Garcia, S.; Garza, J.

2013-01-01

NASA's Space Environment Simulation Laboratory's (SESL) Chamber A, located at the Johnson Space Center in Houston Texas has recently implemented major enhancements of its cryogenic and vacuum systems. The new liquid nitrogen (LN2) thermo-siphon system was successfully commissioned in August of 2012. Chamber A, which has 20 K helium cryo-panels (or shrouds ) which are shielded by 80 K nitrogen shrouds, is capable of simulating a deep space environment necessary to perform ground testing of NASA s James Webb Space Telescope (JWST). Chamber A s previous system used forced flow LN2 cooling with centrifugal pumps, requiring 200,000 liters of LN2 to cool-down and consuming 180,000 liters per day of LN2 in steady operation. The LN2 system did not have the reliability required to meet the long duration test of the JWST, and the cost estimate provided in the initial approach to NASA-JSC by the sub-contractor for refurbishment of the system to meet the reliability goals was prohibitive. At NASA-JSC's request, the JLab Cryogenics Group provided alternative options in 2007, including a thermo-siphon, or natural flow system. This system, eliminated the need for pumps and used one tenth of the original control valves, relief valves, and burst disks. After the thermo-siphon approach was selected, JLab provided technical assistance in the process design, mechanical design, component specification development and commissioning oversight, while the installation and commissioning operations of the system was overseen by the Jacobs Technology/ESC group at JSC. The preliminary commissioning data indicate lower shroud temperatures, 70,000 liters to cool-down and less than 90,000 liters per day consumed in steady operation. All of the performance capabilities have exceeded the design goals. This paper will outline the comparison between the original system and the predicted results of the selected design option, and the commissioning results of thermo-siphon system.

Commissioning of the Liquid Nitrogen Thermo-Siphon System for NASA-JSC Chamber A

Science.gov (United States)

Homan, J.; Montz, M.; Ganni, V.; Sidi-Yekhlef, A.; Knudsen, P.; Garcia, S.; Garza, J.

2013-01-01

NASA s Space Environment Simulation Laboratory s (SESL) Chamber A, located at the Johnson Space Center in Houston Texas has recently implemented major enhancements of its cryogenic and vacuum systems. The new liquid nitrogen (LN) thermo-siphon system was successfully commissioned in August of 2012. Chamber A, which has 20 K helium cryo-panels (or shrouds ) which are shielded by 80 K nitrogen shrouds, is capable of simulating a deep space environment necessary to perform ground testing of NASA s James Webb Space Telescope (JWST). Chamber A s previous system used forced flow LN cooling with centrifugal pumps, requiring 220,000 liters of LN to cool-down and consuming 180,000 liters per day of LN in steady operation. The LN system did not have the reliability required to meet the long duration test of the JWST, and the cost estimate provided in the initial approach to NASA-JSC by the subcontractor for refurbishment of the system to meet the reliability goals was prohibitive. At NASA-JSC s request, the JLab Cryogenics Group provided alternative options in 2007, including a thermo-siphon, or natural flow system. This system, eliminated the need for pumps and used one tenth of the original control valves, relief valves, and burst disks. After the thermo-siphon approach was selected, JLab provided technical assistance in the process design, mechanical design, component specification development and commissioning oversight, while the installation and commissioning operations of the system was overseen by the Jacobs Technology/ESC group at JSC. The preliminary commissioning data indicate lower shroud temperatures, 68,000 liters to cool-down and less than 91,000 liters per day consumed in steady operation. All of the performance capabilities have exceeded the design goals. This paper will outline the comparison between the original system and the predicted results of the selected design option, and the commissioning results of thermo-siphon system.

Simulation of the electron cloud density in BEPC II

International Nuclear Information System (INIS)

Liu Yudong; Guo Zhiyuan; Wang Jiuqing

2004-01-01

Electron Cloud Instability (ECI) may take place in positron storage ring when the machine is operated with multi-bunch positron beam. According to the actual shape of the vacuum chamber in the BEPC II, a program has been developed. With the code, authors can calculate the electron density in the chamber with different length of antechamber and the different secondary electron yield respectively. By the simulation, the possibility to put clearing electrodes in the chamber to reduce the electron density in the central region of the chamber is investigated. The simulation provides meaningful and important results for the BEPC II project and electron cloud instability research

Particle identification using dE/dx in the Mark II detector at the SLC

International Nuclear Information System (INIS)

Boyarski, A.; Coupal, D.P.; Feldman, G.J.; Hanson, G.; Nash, J.; O'Shaughnessy, K.F.; Rankin, P.; Van Kooten, R.

1989-04-01

The central drift chamber in the Mark II detector at the SLAC Linear Collider has been instrumented with 100-MHz Flash-ADCs. Pulse digitization provides particle identification through the measurement of average ionization loss in the chamber. We present the results of a study of system performance and outline the systematic corrections that optimize resolution. The data used are from a short test run at PEP with one-third of the FADCs installed and an extensive cosmic ray sample with the fully instrumented chamber. 11 refs., 9 figs

System for deuterium-tritium mixture filling the working chamber of a dense plasma focus device

International Nuclear Information System (INIS)

Bondar', A.I.; Vyskubov, V.P.; Gerasimov, S.A.

1981-01-01

A gas-vacuum system designed for filling the gas-discharge chamber of a plasma focus device with equal-coaponent deuterium-tritium mixture is described. The system consists of a unit for gaseous mixture prepa ration and a unit for mixture absorption and device evacuation. The system provides the gaseous mixture purification of O 2 and N 2 impurities. Final tritium content in the gas-discharge chamber after tritium removal is not greater than 2x10 8 Bq/l. Tritium content in a sealed box in which the device is placed does not exceed 30 Bq/l that is less than limiting safe value. The conclusion is made that the described system design gives an opportunity to begin experimental studies at plasma focus devices with deuterium-tritium mixture [ru

The CLEO III drift chamber

CERN Document Server

Peterson, D; Briere, R A; Chen, G; Cronin-Hennessy, D; Csorna, S; Dickson, M; Dombrowski, S V; Ecklund, K M; Lyon, A; Marka, S; Meyer, T O; Patterson, J R; Sadoff, A; Thies, P; Thorndike, E H; Urner, D

2002-01-01

The CLEO group at the Cornell Electron Storage Ring has constructed and commissioned a new central drift chamber. With 9796 cells arranged in 47 layers ranging in radius from 13.2 to 79 cm, the new drift chamber has a smaller outer radius and fewer wires than the drift chamber it replaces, but allows the CLEO tracking system to have improved momentum resolution. Reduced scattering material in the chamber gas and in the inner skin separating the drift chamber from the silicon vertex detector provides a reduction of the multiple scattering component of the momentum resolution and an extension of the usable measurement length into the silicon. Momentum resolution is further improved through quality control in wire positioning and symmetry of the electric fields in the drift cells which have provided a reduction in the spatial resolution to 88 mu m (averaged over the full drift range).

CCD camera system for use with a streamer chamber

International Nuclear Information System (INIS)

Angius, S.A.; Au, R.; Crawley, G.C.; Djalali, C.; Fox, R.; Maier, M.; Ogilvie, C.A.; Molen, A. van der; Westfall, G.D.; Tickle, R.S.

1988-01-01

A system based on three charge-coupled-device (CCD) cameras is described here. It has been used to acquire images from a streamer chamber and consists of three identical subsystems, one for each camera. Each subsystem contains an optical lens, CCD camera head, camera controller, an interface between the CCD and a microprocessor, and a link to a minicomputer for data recording and on-line analysis. Image analysis techniques have been developed to enhance the quality of the particle tracks. Some steps have been made to automatically identify tracks and reconstruct the event. (orig.)

Growing and Analyzing Biofilms in Flow Chambers

DEFF Research Database (Denmark)

Tolker-Nielsen, Tim; Sternberg, Claus

2011-01-01

This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic......, and disassembly and cleaning of the system. In addition, embedding and fluorescent in situ hybridization of flow chamber–grown biofilms are addressed. Curr. Protoc. Microbiol. 21:1B.2.1-1B.2.17. © 2011 by John Wiley & Sons, Inc....

Clinical applications of a high speed matrix ionization chamber portal imaging system

International Nuclear Information System (INIS)

Herk, M. van; Gilhuijs, K.; Dalen, A. van; Ven, P. van de; Fencl, W.

1995-01-01

A main disadvantage of the present matrix ionization chamber system for electronic portal imaging is its relatively slow image acquisition of 6 s at full resolution. We have solved this problem by modifying the read-out electronics in two ways: First, faster high voltage switches are applied which work with a higher voltage; Second, faster read-out amplifiers are applied which have reduced cross-talk. With these improvements circuit noise is no longer dominant at typical radiotherapy dose rates. Because the quantum noise level in the matrix ionization chamber system is purely determined by signal integration in the liquid medium, the image scan can now be reduced to as short as 0.55 s with little loss of image quality. However, there is some loss of resolution at readout speed faster than 1.5 s due to speed limitations of the read-out amplifiers. One of the applications of the new device is double exposures for larynx fields. At a reduced dose rate of 125 MU/min, only about 5 MUs are required for a single frame on a 4 MV ABB Dynaray accelerator. Other applications which benefit from the reduced image scan time are time lapse movies. Typically 15 frames per field are made during one fraction. The movies offer both information on patient motion and improved image quality by averaging the frames. Finally, on-line analysis of the images can be performed more easily and has been included in the software package. In can be concluded that the higher speed of the new matrix ionization chamber system is an important improvement for several clinical applications

Data readout system for proportional chambers; Sistema schityvaniya informatsii s proportsional`nykh kamer

Energy Technology Data Exchange (ETDEWEB)

Zhuravlev, N I; Sidorov, V T

1996-12-31

Paper studies data readout system designed for data output from proportional chambers with up to 1000 channel total number. Short descriptions of the above mentioned units made according to CAMAC standard and their main characteristics are presented here. 2 figs.

Chamber for Aerosol Deposition of Bioparticles

Science.gov (United States)

Kern, Roger; Kirschner, Larry

2008-01-01

Laboratory apparatus is depicted that is a chamber for aerosol deposition of bioparticles on surfaces of test coupons. It is designed for primary use in inoculating both flat and three-dimensional objects with approximately reproducible, uniform dispersions of bacterial spores of the genus Bacillus so that the objects could be used as standards for removal of the spores by quantitative surface sampling and/or cleaning processes. The apparatus is also designed for deposition of particles other than bacterial spores, including fungal spores, viruses, bacteriophages, and standard micron-sized beads. The novelty of the apparatus lies in the combination of a controllable nebulization system with a settling chamber large enough to contain a significant number of test coupons. Several companies market other nebulizer systems, but none are known to include chambers for deposition of bioparticles to mimic the natural fallout of bioparticles. The nebulization system is an expanded and improved version of commercially available aerosol generators that include nebulizers and drying columns. In comparison with a typical commercial aerosol generator, this system includes additional, higher-resolution flowmeters and an additional pressure regulator. Also, unlike a typical commercial aerosol generator, it includes stopcocks for separately controlling flows of gases to the nebulizer and drying column. To maximize the degree of uniformity of dispersion of bioaerosol, the chamber is shaped as an axisymmetrical cylinder and the aerosol generator is positioned centrally within the chamber and aimed upward like a fountain. In order to minimize electric charge associated with the aerosol particles, the drying column is made of aluminum, the drying column is in direct contact with an aluminum base plate, and three equally spaced Po-210 antistatic strips are located at the exit end of the drying column. The sides and top of the chamber are made of an acrylic polymer; to prevent

Data acquisition system for a deuteration chamber

International Nuclear Information System (INIS)

Monroy A, L.

1994-01-01

The work present is focusing auxiliary in the experiment the reaction of fusion in cold in the laboratory of Physical of Plasmas of Instituto Nacional de Investigaciones Nucleares. These systems of acquisition of data concrete to register in line surface of pressure and temperature in the gap of 5.6 x 10 -4 to 1 x 10 3 and -270 to 1300 Centigrade degrees with help of personal computer. The manner of purchase in chamber of Deuterium is per middle of thermocouple with the object of whereas any control of the temperature in different point in the some of manner the signal of in for the system is the thermocouple (milli volts), the conversion analogy a digital is mean of Cad of 12 bits rate double slope the out is mean the PPI to send the signal to P C of these manner the read of the thermocouples is translate graphic or digital in the screen of the P C. In the phase of pressure element sensor is measure type Pirani, the measure is of manner of temperature. (Author)

APOLLO 16 COMMANDER JOHN YOUNG ENTERS ALTITUDE CHAMBER FOR TESTS

Science.gov (United States)

1971-01-01

Apollo 16 commander John W. Young prepares to enter the lunar module in an altitude chamber in the Manned Spacecraft Operations Building at the spaceport prior to an altitude run. During the altitude run, in which Apollo 16 lunar module pilot Charles M. Duke also participated, the chamber was pumped down to simulate pressure at an altitude in excess of 200,000 feet. Young, Duke and command module pilot Thomas K. Mattingly II, are training at the Kennedy Space Center for the Apollo 16 mission. Launch is scheduled from Pad 39A, March 17, 1972.

A programming system for bubble chamber photographs measuring tables on-line to a computer

International Nuclear Information System (INIS)

Miche, Roger.

1975-06-01

A programming system available on an industrial computer, type PDP 15/20, performing the exploitation of bubble chamber pictures with the projection tables on line to the computer was developed. This system must suit the particular conditions met in the analysis of photographs from different bubble chambers, the different stage for dealing with the views (scanning, premeasurement, measurement) adapting to different strategies in the handling of measurements. The exploitation of photographs takes place in a conversational mode to which a concrete form is given by sending messages to the operators at the tables and by receiving coded answers. In this framework, the aims of the operating system are: to guide the operator work at the tables while allowing them to interrupt the normal sequence of events, to carry out some elementary logical checks, to write on magnetic tape the checked data with the appropriate labels as required [fr

Effect of chamber characteristics, loading and analysis time on motility and kinetic variables analysed with the CASA-mot system in goat sperm.

Science.gov (United States)

Del Gallego, R; Sadeghi, S; Blasco, E; Soler, C; Yániz, J L; Silvestre, M A

2017-02-01

Several factors unrelated to the semen samples could be influencing in the sperm motility analysis. The aim of the present research was to study the effect of four chambers with different characteristics, namely; slide-coverslip, Spermtrack, ISAS D4C10, and ISAS D4C20 on the sperm motility. The filling procedure (drop or capillarity) and analysis time (0, 120 and 240s), depth of chamber (10 or 20μm) and field on motility variables were analysed by use of the CASA-mot system in goat sperm. Use of the drop-filling chambers resulted in greater values than capillarity-filling chambers for all sperm motility and kinetic variables, except for LIN (64.5% compared with 56.3% of motility for drop- and capillarity-filling chambers respectively, PCASA-mot system with a drop-loaded chamber within 2min after filling the chamber. Copyright © 2016 Elsevier B.V. All rights reserved.

A drift chamber tracking system for muon scattering tomography applications

Science.gov (United States)

Burns, J.; Quillin, S.; Stapleton, M.; Steer, C.; Snow, S.

2015-10-01

Muon scattering tomography (MST) allows the identification of shielded high atomic number (high-Z) materials by measuring the scattering angle of cosmic ray muons passing through an inspection region. Cosmic ray muons scatter to a greater degree due to multiple Coulomb scattering in high-Z materials than low-Z materials, which can be measured as the angular difference between the incoming and outgoing trajectories of each muon. Measurements of trajectory are achieved by placing position sensitive particle tracking detectors above and below the inspection volume. By localising scattering information, the point at which a series of muons scatter can be used to reconstruct an image, differentiating high, medium and low density objects. MST is particularly useful for differentiating between materials of varying density in volumes that are difficult to inspect visually or by other means. This paper will outline the experimental work undertaken to develop a prototype MST system based on drift chamber technology. The planar drift chambers used in this prototype measure the longitudinal interaction position of an ionising particle from the time taken for elections, liberated in the argon (92.5%), carbon dioxide (5%), methane (2.5%) gas mixture, to reach a central anode wire. Such a system could be used to enhance the detection of shielded radiological material hidden within regular shipping cargo.

Long-term monitoring of soil gas fluxes with closed chambers using automated and manual systems

Energy Technology Data Exchange (ETDEWEB)

Scott, A.; Crichton, I.; Ball, B.C.

1999-10-01

The authors describe two gas sample collection techniques, each of which is used in conjunction with custom made automated or manually operated closed chambers. The automated system allows automatic collection of gas samples for simultaneous analysis of multiple trace gas efflux from soils, permitting long-term monitoring. Since the manual system is cheaper to produce, it can be replicated more than the automated and used to estimate spatial variability of soil fluxes. The automated chamber covers a soil area of 0.5 m{sup 2} and has a motor driven lid that remains operational throughout a range of weather conditions. Both systems use gas-tight containers of robust metal construction, which give good sample retention, thereby allowing long-term storage and convenience of transport from remote locations. The containers in the automated system are filled by pumping gas from the closed chamber via a multiway rotary valve. Stored samples from both systems are analyzed simultaneously for N{sub 2}O and CO{sub 2} using automated injection into laboratory-based gas chromatographs. The use of both collection systems is illustrated by results from a field experiment on sewage sludge disposal to land where N{sub 2}O fluxes were high. The automated gas sampling system permitted quantification of the marked temporal variability of concurrent N{sub 2}O and CO{sub 2} fluxes and allowed improved estimation of cumulative fluxes. The automated measurement approach yielded higher estimates of cumulative flux because integration of manual point-in-time observations missed a number of transient high-flux events.

Safety shield for vacuum/pressure-chamber windows

Science.gov (United States)

Shimansky, R. A.; Spencer, R.

1980-01-01

Optically-clear shatter-resistant safety shield protects workers from implosion and explosion of vacuum and pressure windows. Plastic shield is inexpensive and may be added to vacuum chambers, pressure chambers, and gas-filling systems.

Status of the PEP-II asymmetric B-Factory

International Nuclear Information System (INIS)

Mattison, T.S.

1994-11-01

The PEP-II project is an e + e - storage ring complex with unequal energy beams to study CP violation in the B meson system. High luminosity requires a large number of bunches and a low value of beta at the collision point. The high beam current requires advances in vacuum chambers, damped RF cavities, and feedback systems. Machine elements inside the detector are required to achieve low beta values and magnetic separation

A zero-length bellows for the PEP-II High-Energy Ring

International Nuclear Information System (INIS)

Nordby, M.; Daly, E.F.; Kurita, N.; Langton, J.

1995-08-01

Due to the beamline space constrictions and the modular design of the vacuum system, a conventional bellows can not be used everywhere in the PEP-II High-Energy Ring (HER) arcs. A zero-length ''Flex Flange'' was developed which actually performs better than a more standard bellows. The Flex Flange fits the space available while still preserving the modularity of the system. Furthermore, the design provides for an accurate match-up between adjoining octagonal copper chambers despite the large fabrication and assembly tolerances and high operational loads. Beam chamber continuity is ensured by an integral RF seal ring which is easy to install and fault-tolerant. Heating from synchrotron radiation and higher-order mode trapping is managed to ensure a robust connection despite the 3,000 mA beam current of the PEP-II HER. The Flex Flange concept is versatile and adaptable to many applications, yet economical both in space needed and cost

Medical Devices; General Hospital and Personal Use Devices; Classification of the Ultraviolet Radiation Chamber Disinfection Device. Final order.

Science.gov (United States)

2015-11-20

The Food and Drug Administration (FDA or the Agency) is classifying the ultraviolet (UV) radiation chamber disinfection device into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the UV radiation chamber disinfection device classification. The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

Numerical solutions of differential equations of an ionization chamber

International Nuclear Information System (INIS)

Novkovic, D.; Tomasevic, M.; Subotic, K.; Manic, S.

1998-01-01

A system of reduced differential equations generally valid for plane-parallel, cylindrical, and spherical ionization chambers filled with air, which is appropriate for numerical solution, has been derived. The system has been solved for all three geometries. The comparison of the calculated results of Armstrong and Tate, for plane-parallel ionization chambers, and Sprinkle and Tate, for spherical ionization chambers, with the present calculations has shown a good agreement. The calculated values for ionization chambers filled with CO 2 were also in good agreement with the experimental data of Moriuchi et al (author)

Characteristics of a delay-line readout in a cylindrical drift chamber system

International Nuclear Information System (INIS)

Barber, R.; Ahmed, M.W.; Dzemidzic, M.; Empl, A.; Hungerford, E.V.; Lan, K.J.; Wilson, J.; Cooper, M.D.; Gagliardi, C.A.; Haim, D.; Kim, G.J.; Koetke, D.D.; Tribble, R.E.; Van Ausdeln, L.A.

2002-01-01

This paper reports on the design, construction, and operational characteristics of a delay-line readout implemented on the cathode foils of a cylindrical drift chamber system. The readout was used to determine the position of an event along the length of the 1.74 m drift wires in the MEGA detectors used at the Los Alamos Meson Physics Facility. The performance of the system is interpreted by comparison to a PSPICE simulation, and to simple analytical models

Ionization chamber

International Nuclear Information System (INIS)

Jilbert, P.H.

1975-01-01

The invention concerns ionization chambers with particular reference to air-equivalent ionization chambers. In order to ensure that similar chambers have similar sensitivities and responses the surface of the chamber bounding the active volume carries a conducting material, which may be a colloidal graphite, arranged in the form of lines so that the area of the conducting material occupies only a small proportion of the area of said surface. (U.S.)

Data-processing system for bubble-chamber photographs based on PUOS-4 measuring projectors and an ES-1045 computer

International Nuclear Information System (INIS)

Ermolov, P.F.; Kozlov, V.V.; Rukovichkin, V.P.

1988-01-01

A system is described that was developed at the Scientific-Research Institute of Nuclear Physics for processing of the data recorded on stereoscopic photographs from large bubble chambers and hybrid spectrometers using PUOS-4 measuring projectors, an Elektronika-60 microcomputer, and an ES-1045 computer. The system structure, the main programmable interfaces, and the intercomputer communications are examined. The mean-square error of the measuring channels of the system, determined from calibration measurements, is within 1.3-3.5 μm; the standard deviation of the coordinates of the measured points with respect to the track in the plane of the photograph is 6 μm. The system is widely used at the institute for analysis of data from experiments in high-energy physics performed with the European Hybrid Spectrometer and the Mirabel large bubble chamber. Approximately 80,000 stereoscopic photographs have been processed and the system is being prepared to process data from the Skat bubble chamber and a spectrometer with a vertex detector that is under construction

Trigger drift chamber for the upgraded mark II detector at PEP

Science.gov (United States)

Ford, W. T.; Smith, J. G.; Wagner, S. R.; Weber, P.; White, S. L.; Alvarez, M.; Calviño, F.; Fernandez, E.

1987-04-01

A small cylindrical track detector was built as an array of single-wire drift cells with aluminized mylar cathode tubes. Point measurement resolution of ˜ 90 μm was achieved with a drift gas of 50% argon-50% ethane at atmospheric pressure. The chamber construction, electronics, and calibration are discussed. Performance results from PEP colliding-beam data are presented.

A CDC 1700 on-line system for the analysis, data logging and monitoring of big bubble chamber pictures

International Nuclear Information System (INIS)

Guyonnet, J.-L.

1975-01-01

This work presents the analysis system of large bubble chamber such as Gargamelle, BEBC pictures realized in the heavy liquid bubble chamber group with scanning and measurement stations on-line with a CDC 1700 computer. This work deals with the general characteristics of these stations and of the computer, and puts emphasis on the conception and functions of the analysis programmes: scanning, measurement and data processing. The data acquisition system runs in a context of real time multiprogrammation [fr

Calculational-theoretical studies of the system of local automated regulators and lateral ionization chambers

International Nuclear Information System (INIS)

Aleksakov, A.N.; Emel'yanov, I.Ya.; Nikolaev, E.V.; Panin, V.M.; Podlazov, L.N.; Rogova, V.D.

1987-01-01

Methods of engineering synthesis of the systems for nuclear reactor local automated power regulation and radial-azimuthal energy distribution stabilization operating according to lateral ionization chamber signals are described. Results of calculational-theoretical investigations into the system efficiency and peculiarities of its reaction to some perturbations typical of the RBMK type reactors are considered

Tokamak DEMO-FNS: Concept of magnet system and vacuum chamber

Energy Technology Data Exchange (ETDEWEB)

Azizov, E. A., E-mail: Azizov-EA@nrcki.ru; Ananyev, S. S. [National Research Center Kurchatov Institute (Russian Federation); Belyakov, V. A.; Bondarchuk, E. N.; Voronova, A. A. [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (Russian Federation); Golikov, A. A. [National Research Center Kurchatov Institute (Russian Federation); Goncharov, P. R. [Peter the Great St. Petersburg Polytechnic University (Russian Federation); Dnestrovskij, A. Yu. [National Research Center Kurchatov Institute (Russian Federation); Zapretilina, E. R. [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (Russian Federation); Ivanov, D. P. [National Research Center Kurchatov Institute (Russian Federation); Kavin, A. A.; Kedrov, I. V. [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (Russian Federation); Klischenko, A. V.; Kolbasov, B. N. [National Research Center Kurchatov Institute (Russian Federation); Krasnov, S. V. [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (Russian Federation); Krylov, A. I. [National Research Center Kurchatov Institute (Russian Federation); Krylov, V. A.; Kuzmin, E. G. [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (Russian Federation); Kuteev, B. V. [National Research Center Kurchatov Institute (Russian Federation); Labusov, A. N. [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (Russian Federation); and others

2016-12-15

The level of knowledge accumulated to date in the physics and technologies of controlled thermonuclear fusion (CTF) makes it possible to begin designing fusion—fission hybrid systems that would involve a fusion neutron source (FNS) and which would admit employment for the production of fissile materials and for the transmutation of spent nuclear fuel. Modern Russian strategies for CTF development plan the construction to 2023 of tokamak-based demonstration hybrid FNS for implementing steady-state plasma burning, testing hybrid blankets, and evolving nuclear technologies. Work on designing the DEMO-FNS facility is still in its infancy. The Efremov Institute began designing its magnet system and vacuum chamber, while the Kurchatov Institute developed plasma-physics design aspects and determined basic parameters of the facility. The major radius of the plasma in the DEMO-FNS facility is R = 2.75 m, while its minor radius is a = 1 m; the plasma elongation is k{sub 95} = 2. The fusion power is P{sub FUS} = 40 MW. The toroidal magnetic field on the plasma-filament axis is B{sub t0} = 5 T. The plasma current is I{sub p} = 5 MA. The application of superconductors in the magnet system permits drastically reducing the power consumed by its magnets but requires arranging a thick radiation shield between the plasma and magnet system. The central solenoid, toroidal-field coils, and poloidal-field coils are manufactured from, respectively, Nb{sub 3}Sn, NbTi and Nb{sub 3}Sn, and NbTi. The vacuum chamber is a double-wall vessel. The space between the walls manufactured from 316L austenitic steel is filled with an iron—water radiation shield (70% of stainless steel and 30% of water).

ITER cryostat main chamber and vacuum vessel pressure suppression system design

International Nuclear Information System (INIS)

Ito, Akira; Nakahira, Masataka; Takahashi, Hiroyuki; Tada, Eisuke; Nakashima, Yoshitane; Ueno, Osamu

1999-03-01

Design of Cryostat Main Chamber and Vacuum Vessel Pressure Suppression System (VVPS) of International Thermonuclear Experimental Reactor (ITER) has been conducted. The cryostat is a cylindrical vessel that includes in-vessel component such as vacuum vessel, superconducting toroidal coils and poloidal coils. This cryostat provides the adiabatic vacuum about 10 -4 Pa for the superconducting coils operating at 4 K and forms the second confinement barrier to tritium. The adiabatic vacuum is to reduce thermal loads applied to the superconducting coils and their supports so as to keep their temperature 4 K. The VVPS consists of a suppression tank located under the lower bio-shield and 4 relief pipes to connect the vacuum vessel and the suppression tank. The VVPS is to keep the maximum pressure rise of the vacuum vessel below the design value of 0.5 MPa in case of the in-vessel LOCA (water spillage from in-vessel component). The spilled water and steam are lead to the suppression tank through the relief pipes when the internal pressure of vacuum vessel is over 0.2 MPa, and then the internal pressure is kept below 0.5 MPa. This report summarizes the structural design of the cryostat main chamber and pressure suppression system, together with their fabrication and installation. (author)

ITER cryostat main chamber and vacuum vessel pressure suppression system design

Energy Technology Data Exchange (ETDEWEB)

Ito, Akira; Nakahira, Masataka; Takahashi, Hiroyuki; Tada, Eisuke [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nakashima, Yoshitane; Ueno, Osamu

1999-03-01

Design of Cryostat Main Chamber and Vacuum Vessel Pressure Suppression System (VVPS) of International Thermonuclear Experimental Reactor (ITER) has been conducted. The cryostat is a cylindrical vessel that includes in-vessel component such as vacuum vessel, superconducting toroidal coils and poloidal coils. This cryostat provides the adiabatic vacuum about 10{sup -4} Pa for the superconducting coils operating at 4 K and forms the second confinement barrier to tritium. The adiabatic vacuum is to reduce thermal loads applied to the superconducting coils and their supports so as to keep their temperature 4 K. The VVPS consists of a suppression tank located under the lower bio-shield and 4 relief pipes to connect the vacuum vessel and the suppression tank. The VVPS is to keep the maximum pressure rise of the vacuum vessel below the design value of 0.5 MPa in case of the in-vessel LOCA (water spillage from in-vessel component). The spilled water and steam are lead to the suppression tank through the relief pipes when the internal pressure of vacuum vessel is over 0.2 MPa, and then the internal pressure is kept below 0.5 MPa. This report summarizes the structural design of the cryostat main chamber and pressure suppression system, together with their fabrication and installation. (author)

Glove box chamber

International Nuclear Information System (INIS)

Cox, M.E.; Cox, M.E.

1975-01-01

An environmental chamber is described which enables an operator's hands to have direct access within the chamber without compromising a special atmosphere within such chamber. A pair of sleeves of a flexible material are sealed to the chamber around associated access apertures and project outwardly from such chamber. Each aperture is closed by a door which is openable from within the sleeve associated therewith so that upon an operator inserting his hand and arm through the sleeve, the operator can open the door to have access to the interior of the chamber. A container which is selectively separable from the remainder of the chamber is also provided to allow objects to be transferred from the chamber without such objects having to pass through the ambient atmosphere. An antechamber permitting objects to be passed directly into the chamber from the ambient atmosphere is included. (auth)

The OPAL vertex drift chamber

International Nuclear Information System (INIS)

Carter, J.R.; Elcombe, P.A.; Hill, J.C.; Roach, C.M.; Armitage, J.C.; Carnegie, R.K.; Estabrooks, P.; Hemingway, R.; Karlen, D.; McPherson, A.; Pinfold, J.; Roney, J.M.; Routenburg, P.; Waterhouse, J.; Hargrove, C.K.; Klem, D.; Oakham, F.G.; Carter, A.A.; Jones, R.W.L.; Lasota, M.M.B.; Lloyd, S.L.; Pritchard, T.W.; Wyatt, T.R.

1990-01-01

A high precision vertex drift chamber has been installed in the OPAL experiment at LEP. The design of the chamber and the associated readout electronics is described. The performance of the system has been studied using cosmic ray muons and the results of these studies are presented. A space resolution of 50 μm in the drift direction is obtained using the OPAL central detector gas mixture at 4 bar. (orig.)

Measurements of CO2 exchange with an automated chamber system throughout the year: challenges in measuring nighttime respiration on porous peat soil

Science.gov (United States)

Koskinen, M.; Minkkinen, K.; Ojanen, P.; Kämäräinen, M.; Laurila, T.; Lohila, A.

2013-08-01

We built an automatic chamber system to measure greehouse gas (GHG) exchange in forested peatland ecosystems. We aimed to build a system robust enough which would work throughout the year and could measure through a changing snowpackin addition to producing annual GHG fluxes by integrating the measurements without the need of using models. The system worked rather well throughout the year, but it was not service free. Gap filling of data was still necessary. We observed problems in carbon dioxide (CO2) flux estimation during calm summer nights, when a CO2 concentration gradient from soil/moss system to atmosphere builds up. Chambers greatly overestimated the nighttime respiration. This was due to the disturbance caused by the chamber to the soil-moss CO2 gradient and consequent initial pulse of CO2 to the chamber headspace. We tested different flux calculation and measurement methods to solve this problem. The estimated flux was strongly dependent on (1) the type of the fit (linear and polynomial), (2) the starting point of the fit after closing the chamber, (3) the length of the fit, (4) the speed of the fan mixing the air inside the chamber, and (5) atmospheric turbulence (friction velocity, u*). The best fitting method (the most robust, least random variation) was linear fitting with the period of 120-240 s after chamber closure. Furthermore, the fan should be adjusted to spin at minimum speed to avoid the pulse-effect, but it should be kept on to ensure mixing. If nighttime problems cannot be solved, emissions can be estimated using daytime data from opaque chambers.

Quality control of ATLAS muon chambers

CERN Document Server

Fabich, Adrian

ATLAS is a general-purpose experiment for the future Large Hadron Collider (LHC) at CERN. Its Muon Spectrometer will require ∼ 5500m2 of precision tracking chambers to measure the muon tracks along a spectrometer arm of 5m to 15m length, embedded in a magnetic field of ∼ 0.5T. The precision tracking devices in the Muon System will be high pressure drift tubes (MDTs). Approximately 370,000 MDTs will be assembled into ∼ 1200 drift chambers. The performance of the MDT chambers is very much dependent on the mechanical quality of the chambers. The uniformity and stability of the performance can only be assured providing very high quality control during production. Gas tightness, high-voltage behaviour and dark currents are global parameters which are common to gas detectors. For all chambers, they will be tested immediately after the chamber assembly at every production site. Functional tests, for example radioactive source scans and cosmic-ray runs, will be performed in order to establish detailed performan...

Dilution refrigeration with multiple mixing chambers

International Nuclear Information System (INIS)

Coops, G.M.

1981-01-01

A dilution refrigerator is an instrument to reach temperatures in the mK region in a continuous way. The temperature range can be extended and the cooling power can be enlarged by adding an extra mixing chamber. In this way we obtain a double mixing chamber system. In this thesis the theory of the multiple mixing chamber is presented and tested on its validity by comparison with the measurements. Measurements on a dilution refrigerator with a circulation rate up to 2.5 mmol/s are also reported. (Auth.)

wire chamber

CERN Multimedia

Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

Trigger drift chamber for the upgraded Mark II detector at PEP

International Nuclear Information System (INIS)

Ford, W.T.; Smith, J.G.; Wagner, S.R.; Weber, P.; White, S.L.; Alvarez, M.; Calvino, F.; Fernandez, E.; Universidad Autonoma de Barcelona

1987-01-01

A small cylindrical track detector was built as an array of single-wire drift cells with aluminized mylar cathode tubes. Point measurement resolution of ∝90 μm was achieved with a drift gas of 50% argon-50% ethane at atmospheric pressure. The chamber construction, electronics, and calibration are discussed. Performance results from PEP colliding-beam data are presented. (orig.)

Automated system with LabVIEW for the obtention of voltage plateau, graphic of sensitivity and operation voltage in an ionization chamber

International Nuclear Information System (INIS)

Cruz E, P.

2001-01-01

The work developed for the Laguna Verde Nuclear Power Central allows to obtain the voltage plateau, graphic of sensitivity and operation voltage of three types of ionization chambers which are used in their monitoring systems of process radiation. The automated system is based in a personal computer (Pc) for controlling and acquiring data from the different instruments used, its programming was realized with virtual instruments (LabVIEW, National Instruments software). The system also realizes a diagnosis of the ionization chamber and determine whether the parameters obtained are inside of the manufacturer specifications, that is to say, it determines when the ionization chamber must be replaced. (Author)

Note: Small anaerobic chamber for optical spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Chauvet, Adrien A. P., E-mail: adrien.chauvet@gmail.com; Chergui, Majed [Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide, ISIC, Faculté des Sciences de Base, Station 6, 1015 Lausanne (Switzerland); Agarwal, Rachna; Cramer, William A. [Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907 (United States)

2015-10-15

The study of oxygen-sensitive biological samples requires an effective control of the atmosphere in which they are housed. In this aim however, no commercial anaerobic chamber is adequate to solely enclose the sample and small enough to fit in a compact spectroscopic system with which analysis can be performed. Furthermore, spectroscopic analysis requires the probe beam to pass through the whole chamber, introducing a requirement for adequate windows. In response to these challenges, we present a 1 l anaerobic chamber that is suitable for broad-band spectroscopic analysis. This chamber has the advantage of (1) providing access, via a septum, to the sample and (2) allows the sample position to be adjusted while keeping the chamber fixed and hermetic during the experiment.

Structural Analysis of Extended Plasma Focus Chamber

International Nuclear Information System (INIS)

Mohd Azhar Ahmad; Abdul Halim Baijan; Siti Aiasah Hashim

2016-01-01

Accelerator Development Centre (ADC) of Nuclear Malaysia intends to upgrade the plasma focus device. It involves the extension part placed on top of the existing plasma focus vacuum chamber. This extended vacuum chamber purposely to give an extra space in conducting experiments on the existing plasma focus chamber. The aim of upgrading the plasma focus device is to solve the limitation in research and analysis of sample due to its done in an open system that cause analysis of samples is limited and less optimal. This extended chamber was design in considering the ease of fabrication as well as durability of its structural. Thus, this paper discusses the structural analysis in term of pressure loading effect in extended chamber. (author)

Ambient dose equivalent measurements in secondary radiation fields at proton therapy facility CCB IFJ PAN in Krakow using recombination chambers

Directory of Open Access Journals (Sweden)

Jakubowska Edyta A.

2016-03-01

Full Text Available This work presents recombination methods used for secondary radiation measurements at the Facility for Proton Radiotherapy of Eye Cancer at the Institute for Nuclear Physics, IFJ, in Krakow (Poland. The measurements of H*(10 were performed, with REM-2 tissue equivalent chamber in two halls of cyclotrons AIC-144 and Proteus C-235 and in the corridors close to treatment rooms. The measurements were completed by determination of gamma radiation component, using a hydrogen-free recombination chamber. The results were compared with the measurements using rem meter types FHT 762 (WENDI-II and NM2 FHT 192 gamma probe and with stationary dosimetric system.

Rapid-Cycling Bubble-Chamber, details

CERN Multimedia

CERN PhotoLab

1980-01-01

Parts of the hydraulic expansion system of the Rapid-Cycling Bubble-Chamber (RCBC). RCBC was the largest of 3 rapid-cycling bubble-chambers (the others were LEBC and HOLEBC), used as target- and vertex-detectors within the European Hybrid Spectrometer (EHS) in the SPS North Area (EHN1). RCBC contained 250 l of liquid hydrogen and was located inside a 3 T superconducting magnet. It was designed for 30 expansions/s (100 times faster than BEBC), the system shown here allowed 50 expansions/s. RCBC operated from 1981 to 1983 for experiments NA21, NA22 and NA23 at a rate of 15 expansions/s, clocking up a total of over 4 million. In the rear, at left, is bearded Lucien Veillet; Augustin Didona is at the right. See also 8001009. The installation of the piston assembly in the RCBC chamber body is shown in the Annual Report 1980, p.65.

Test chamber

NARCIS (Netherlands)

Leferink, Frank Bernardus Johannes

2009-01-01

A test chamber for measuring electromagnetic radiation emitted by an apparatus to be tested or for exposing an apparatus to be tested to an electromagnetic radiation field. The test chamber includes a reverberation chamber made of a conductive tent fabric. To create a statistically uniform field in

Overview of the SECOM II communications system

International Nuclear Information System (INIS)

Olson, W.D.

1977-04-01

The conversion of the SECOM system to the SECOM II configuration has been completed and all communications between the central control station and vehicles carrying nuclear weapons and special nuclear materials are being handled by the SECOM II system. A summary of the system characteristics and the improvements achieved over the all-voice system is shown. Through the combined efforts of ALO and Sandia personnel, the transition from SECOM to SECOM II was achieved with a minimum disruption to the operation of the ERDA transportation system

Design and testing of a model CELSS chamber robot

Science.gov (United States)

Davis, Mark; Dezego, Shawn; Jones, Kinzy; Kewley, Christopher; Langlais, Mike; McCarthy, John; Penny, Damon; Bonner, Tom; Funderburke, C. Ashley; Hailey, Ruth

1994-08-01

A robot system for use in an enclosed environment was designed and tested. The conceptual design will be used to assist in research performed by the Controlled Ecological Life Support System (CELSS) project. Design specifications include maximum load capacity, operation at specified environmental conditions, low maintenance, and safety. The robot system must not be hazardous to the sealed environment, and be capable of stowing and deploying within a minimum area of the CELSS chamber facility. This design consists of a telescoping robot arm that slides vertically on a shaft positioned in the center of the CELSS chamber. The telescoping robot arm consists of a series of links which can be fully extended to a length equal to the radius of the working envelope of the CELSS chamber. The vertical motion of the robot arm is achieved through the use of a combination ball screw/ball spline actuator system. The robot arm rotates cylindrically about the vertical axis through use of a turntable bearing attached to a central mounting structure fitted to the actuator shaft. The shaft is installed in an overhead rail system allowing the entire structure to be stowed and deployed within the CELSS chamber. The overhead rail system is located above the chamber's upper lamps and extends to the center of the CELSS chamber. The mounting interface of the actuator shaft and rail system allows the entire actuator shaft to be detached and removed from the CELSS chamber. When the actuator shaft is deployed, it is held fixed at the bottom of the chamber by placing a square knob on the bottom of the shaft into a recessed square fitting in the bottom of the chamber floor. A support boot ensures the rigidity of the shaft. Three student teams combined into one group designed a model of the CELSS chamber robot that they could build. They investigated materials, availability, and strength in their design. After the model arm and stand were built, the class performed pre-tests on the entire system

Improvement of the drift chamber system in the SAPHIR detector and first measurements of the Φ meson production at threshold

International Nuclear Information System (INIS)

Scholmann, J.N.

1996-09-01

The SAPHIR detector at ELSA enables the measurement of photon induced Φ meson production from threshold up to 3 GeV in the full kinematical range. A considerable improvement of the drift chamber system is a precondition of gaining the necessary data rate in an acceptable time. The research focuses attention on the choice of the chamber gas and on a different mechanical construction, so as to minimize the negative influences of the photon beam crossing the sensitive volume of the drift chamber system. In addition, first preliminary results of the total and the differential cross section for the Φ meson production close to threshold were evaluated. (orig.)

Monitored Drift Chambers in the ATLAS Detector

CERN Multimedia

Herten, G

Monitored Drift Chambers (MDT) are used in the ATLAS Detector to measure the momentum of high energy muons. They consist of drift tubes, which are filled with an Ar-CO2 gas mixture at 3 bar gas pressure. About 1200 drift chambers are required for ATLAS. They are up to 6 m long. Nevertheless the position of every wire needs to be known with a precision of 20 µm within a chamber. In addition, optical alignment sensors are required to measure the relative position of adjacent chambers with a precision of 30µm. This gigantic task seems impossible at first instance. Indeed it took many years of R&D to invent the right tools and methods before the first chamber could be built according to specifications. Today, at the time when 50% of the chambers have been produced, we are confident that the goal for ATLAS can be reached. The mechanical precision of the chambers could be verified with the x-ray tomograph at CERN. This ingenious device, developed for the MDT system, is able to measure the wire position insid...

Tracking with wire chambers at high luminosities

International Nuclear Information System (INIS)

Hanson, G.G.

1989-12-01

Radiation damage and rate limitations impose severe constraints on wire chambers at the SSC. Possible conceptual designs for wire chamber tracking systems that satisfy these constraints are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 11 refs., 10 figs

Recent developments in wire chamber tracking at SSC

International Nuclear Information System (INIS)

Ogren, H.

1990-01-01

All of the major SSC proposed detectors use wire chambers in their tracking systems. The feasibility of wire chambers in an SSC detector has now been established by a number of groups planning detectors at SSC. The major advances during the past year in understanding straw tube drift chambers are presented and several innovations in gaseous wire chambers are discussed. The R and D section will concentrate on progress in drift cell design, electronics and signal processing, and engineering aspects of the tracking designs

Tasks related to increase of RA reactor exploitation and experimental potential, 01. Designing the protection chamber in the RA reactor hall for handling the radioactive experimental equipment (I-II) Part II, Vol. II

International Nuclear Information System (INIS)

Pavicevic, M.

1963-07-01

This second volume of the project for construction of the protection chamber in the RA reactor hall for handling the radioactive devices includes the technical description of the chamber, calculation of the shielding wall thickness, bottom lead plate, horizontal stability of the chamber, cost estimation, and the engineering drawings

A system for the study of molecular contamination. [experimental vacuum chambers

Science.gov (United States)

Dillow, C. F.; Allen, T. H.; Linford, R. M. F.; Richmond, R. G.

1975-01-01

An experimental vacuum chambers was designed and fabricated to provide a wide range of experimental capability. This work chamber assembly (WCA) was conceived to establish the proof-of-principle of various techniques for studying the kinetics of contaminants and their effects. It incorporates the capability for depositing both optical and contaminant films on temperature-controlled samples, and for in-situ measurements of the vacuum ultraviolet reflectance. Ellipsometer optics are mounted on the chamber for film thickness determinations, and other features include access ports for radiation sources and instrumentation.

NSLS-II booster timing system

International Nuclear Information System (INIS)

Cheblakov, P.; Karnaev, S.; De Long, J.

2012-01-01

NSLS-II light source includes the main storage ring with beam lines and injection part consisting of 200 MeV linac, a full-energy 3 GeV booster synchrotron and two transport lines. The booster timing system is a part of NSLS-II timing system which uses hardware from MicroResearch Finland: Event Generator (EVG) and Event Receivers (EVRs). The booster timing is based on the events coming from NSLS-II EVG: 'Pre-Injection', 'Injection', 'Pre-Extraction', 'Extraction'. These events are referenced to the selected RF bucket of the storage ring and correspond to the first RF bucket of the booster. EVRs provide triggers both for the injection and the extraction pulse devices. EVRs also provide the timing of booster cycle operation and generation of events for cycle-to-cycle updates of pulsed and ramping parameters, and synchronization of the booster beam instrumentation devices. This paper describes the final design of the booster timing system. The timing system functional diagrams and block diagram are presented. (authors)

Optimized Vibration Chamber for Landslide Sensory and Alarm System

Science.gov (United States)

Ismail, Eliza Sabira Binti; Hadi Habaebi, Mohamed; Daoud, Jamal I.; Rafiqul Islam, Md

2017-11-01

Landslide is one of natural hazard that is not unfamiliar disaster in Malaysia. Malaysia has experienced this disaster many times since 1969. This natural hazard has become a major research concern for Malaysian government when many people were injured badly and even had been killed. Many previous research works published in the open literature aimed at designing a system that could detect landslide in early stage before the landslide becomes catastrophic. This paper presents the early works on a major work-in-progress landslide early warning system for Malaysian environment. The aim of this system is to develop the most efficiently reliable cost-effective system in which slight earth movements are monitored continuously. The challenge this work aims at is to work with a low budget system that produces efficient performance. Hence, the material used is off-the-shelf. Early design optimization results of the vibration sensor used is quite promising detecting the slightest faint tremors, which are amplified using the best vibration chamber available. It is shown that the choice of proper pipe length and diameter dimensions in combination to a gravel to exaggerate the produced higher sensitivity level noise of 5 dB.

Proton beam monitor chamber calibration

International Nuclear Information System (INIS)

Gomà, C; Meer, D; Safai, S; Lorentini, S

2014-01-01

The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences—of the order of 3%—were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth—i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers—rather than cylindrical chambers—for the reference dosimetry of pseudo-monoenergetic proton beams. (paper)

Measurements of CO2 exchange with an automated chamber system throughout the year: challenges in measuring night-time respiration on porous peat soil

Directory of Open Access Journals (Sweden)

M. Koskinen

2014-01-01

Full Text Available We built an automatic chamber system to measure greenhouse gas (GHG exchange in forested peatland ecosystems. We aimed to build a system robust enough which would work throughout the year and could measure through a changing snowpack in addition to producing annual GHG fluxes by integrating the measurements without the need of using models. The system worked rather well throughout the year, but it was not service free. Gap filling of data was still necessary. We observed problems in carbon dioxide (CO2 respiration flux estimation during calm summer nights, when a CO2 concentration gradient from soil/moss system to atmosphere builds up. Chambers greatly overestimated the night-time respiration. This was due to the disturbance caused by the chamber to the soil-moss CO2 gradient and consequent initial pulse of CO2 to the chamber headspace. We tested different flux calculation and measurement methods to solve this problem. The estimated flux was strongly dependent on (1 the starting point of the fit after closing the chamber, (2 the length of the fit, (3 the type of the fit (linear and polynomial, (4 the speed of the fan mixing the air inside the chamber, and (5 atmospheric turbulence (friction velocity, u*. The best fitting method (the most robust, least random variation for respiration measurements on our sites was linear fitting with the period of 120–240 s after chamber closure. Furthermore, the fan should be adjusted to spin at minimum speed to avoid the pulse-effect, but it should be kept on to ensure mixing. If night-time problems cannot be solved, emissions can be estimated using daytime data from opaque chambers.

Measurements of CO2 exchange with an automated chamber system throughout the year: challenges in measuring night-time respiration on porous peat soil

Science.gov (United States)

Koskinen, M.; Minkkinen, K.; Ojanen, P.; Kämäräinen, M.; Laurila, T.; Lohila, A.

2014-01-01

We built an automatic chamber system to measure greenhouse gas (GHG) exchange in forested peatland ecosystems. We aimed to build a system robust enough which would work throughout the year and could measure through a changing snowpack in addition to producing annual GHG fluxes by integrating the measurements without the need of using models. The system worked rather well throughout the year, but it was not service free. Gap filling of data was still necessary. We observed problems in carbon dioxide (CO2) respiration flux estimation during calm summer nights, when a CO2 concentration gradient from soil/moss system to atmosphere builds up. Chambers greatly overestimated the night-time respiration. This was due to the disturbance caused by the chamber to the soil-moss CO2 gradient and consequent initial pulse of CO2 to the chamber headspace. We tested different flux calculation and measurement methods to solve this problem. The estimated flux was strongly dependent on (1) the starting point of the fit after closing the chamber, (2) the length of the fit, (3) the type of the fit (linear and polynomial), (4) the speed of the fan mixing the air inside the chamber, and (5) atmospheric turbulence (friction velocity, u*). The best fitting method (the most robust, least random variation) for respiration measurements on our sites was linear fitting with the period of 120-240 s after chamber closure. Furthermore, the fan should be adjusted to spin at minimum speed to avoid the pulse-effect, but it should be kept on to ensure mixing. If night-time problems cannot be solved, emissions can be estimated using daytime data from opaque chambers.

Radial semiconductor drift chambers

International Nuclear Information System (INIS)

Rawlings, K.J.

1987-01-01

The conditions under which the energy resolution of a radial semiconductor drift chamber based detector system becomes dominated by the step noise from the detector dark current have been investigated. To minimise the drift chamber dark current attention should be paid to carrier generation at Si/SiO 2 interfaces. This consideration conflicts with the desire to reduce the signal risetime: a higher drift field for shorter signal pulses requires a larger area of SiO 2 . Calculations for the single shaping and pseudo Gaussian passive filters indicate that for the same degree of signal risetime sensitivity in a system dominated by the step noise from the detector dark current, the pseudo Gaussian filter gives only a 3% improvement in signal/noise and 12% improvement in rate capability compared with the single shaper performance. (orig.)

Commissioning of a 20 K Helium Refrigeration System for NASA-JSC Chamber A

Science.gov (United States)

Homan, J.; Redman, R.; Ganni, V.; Sidi-Yekhlef, A.; Knudsen, P.; Norton, R.; Lauterbach, J.; Linza, R.; Vargas, G.

2013-01-01

A new 20 K helium refrigerator installed at NASA Johnson Space Center s Space Environment Simulation Laboratory (SESL) was successfully commissioned and tested in 2012. The refrigerator is used to create a deep space environment within SESL s Chamber A to perform ground testing of the James Webb Space Telescope (JWST). The chamber previously and currently still has helium cryo-pumping panels (CPP) and liquid nitrogen shrouds used to create low earth orbit environments. Now with the new refrigerator and new helium shrouds the chamber can create a deep space environment. The process design, system analysis, specification development, and commissioning oversight were performed by the cryogenics department at Jefferson Lab, while the contracts and system installation was performed by the ESC group at JSC. Commissioning data indicate an inverse coefficient of performance better than 70 W/W for a 18 kW load at 20 K (accounting for liquid nitrogen pre-cooling power) that remains essentially constant down to one third of this load. Even at 10 percent of the maximum capacity, the performance is better than 150 W/W at 20 K. The refrigerator exceeded all design goals and demonstrated the ability to support a wide load range from 10 kW at 15 K to 100 kW at 100 K. The refrigerator is capable of operating at any load temperature from 15 K to ambient with tight temperature stability. The new shroud (36 tons of aluminum) can be cooled from room temperature to 20 K in 24 hours. This paper will outline the process design and commissioning results.

Tracking with wire chambers at the SSC

International Nuclear Information System (INIS)

Hanson, G.G.; Gundy, M.C.; Palounek, A.P.T.

1989-07-01

Limitations placed on wire chambers by radiation damage and rate requirements in the SSC environment are reviewed. Possible conceptual designs for wire chamber tacking systems that meet these requirements are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 13 refs., 11 fig., 1 tab

Automation of the reading of an ionization chamber: study and design of a data transfer system

International Nuclear Information System (INIS)

RANDRIAMAHOLISOA, C.O.

1999-01-01

Management of information obtained through ionization chamber, type of detector the most employed in centers or institutions using ionizing radiation machines and radioactive sources, is done manually because data are fed into computers from keyboard. This procedure presents hazards of loss and bad transcription of information. A more practical way of getting over this handicap is the setting up of a system that transfers data from ionization chamber into computer. Thereafter, it will be easier for the user to adjust his data processing software to the system underconsideration. This system, even though not directly designed to process data, that being a specific task of each user, is constituted of an electronic aspect which plays the interface part between them. It takes account parameters having relevance to the quality and the quantity of information put out by the detector [fr

Design and Development of a control system for the Drift Tube Chamber High Voltage Power Supply

CERN Document Server

Leon Vega, Luis Gerardo

2017-01-01

This paper contains information related to the design and development of a control and data acquisition manager implemented in WinCC, a Siemens SCADA system. The goal was to manage a CAEN HV (High Voltage) system for powering a Drift Tube (DT) chamber of the CMS experiment. Basically, this manager consists of two sections: a friendly user interface and powerful scripts to manage the back-end. It is in charge of adjusting the power supply settings to the correct values needed for the DT Chamber operations (ON, OFF, Standby), depending of the requirements of the operator, managing automatically all the transition process. Also, the manager is in charge of configuring the archiving process for acquiring data and providing the history of the system. It also implements the monitoring of the status of each connected channel, alerting in case it is needed.

Installation and Commissioning of the new GLM Implantation Chamber

CERN Document Server

Pohl, Christoph

2016-01-01

Summer student report about the work with the new implantation chamber for the GLM branch of ISOLDE. In the context of this project an API for the vacuum system of the new chamber was developed and implemented in web application that will be used to control the new implantation chamber at some point.

National Ignition Facility Target Chamber

International Nuclear Information System (INIS)

Wavrik, R W; Cox, J R; Fleming, P J

2000-01-01

On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This was

OPAL jet chamber full scale prototype

Energy Technology Data Exchange (ETDEWEB)

Fischer, H M; Hauschild, M; Hartmann, H; Hegerath, A; Boerner, H; Burckhart, H J; Dittmar, M; Hammarstroem, R; Heuer, R D; Mazzone, L

1986-12-01

The concept of a jet chamber for the central detector of OPAL has been tested with a full scale prototype. The design of this prototype, its mechanical and electrical structure and its support system for high voltage, gas, laser calibration and readout are described. Operating experience has been gathered since summer 1984. The chamber performance in terms of spatial resolution and particle identification capability is given.

OPAL jet chamber full-scale prototype

Energy Technology Data Exchange (ETDEWEB)

Fischer, H M; Hauschild, M; Hartmann, H; Hegerath, A; Boerner, H; Burckhart, H J; Dittmar, M; Hammarstroem, R; Heuer, R D; Mazzone, L

1986-12-01

The concept of a jet chamber for the central detector of OPAL was tested with a full scale prototype. The design of this prototype, its mechanical and electrical structure and its support system for high voltage, gas, laser calibration, and readout are described. Operating experience was gathered since summer 1984. The chamber performance in terms of spatial resolution and particle identification capability is given.

Measuring the sensitivity of a boron-lined ion chamber

International Nuclear Information System (INIS)

Barton, D.M.

1992-03-01

Boron-lined ion chambers are used to monitor external neutron flux from fissionable materials assembled at the Los Alamos Critical Assembly Experiment Facility. The sensitivity of these chambers must be measured periodically in order to detect changes in filling gas and to evaluate other factors that may affect chamber performance. We delineate a procedure to measure ion chamber response using a particular neutron source ( 239 PuBe) in a particular moderating geometry of polyethylene. We also discuss use of the amplifier, high-voltage power supply, recorders, and scram circuits that comprise the complete ion chamber monitoring system

Multiple chamber ionization detector

International Nuclear Information System (INIS)

Solomon, E.E.

1980-01-01

A multi-chambered ionisation detector enables the amount of radiation entering each chamber from a single radioactive, eg β, source to be varied by altering the proportion of the source protruding into each chamber. Electrodes define chambers and an extended radioactive source is movable to alter the source length in each chamber. Alternatively, the source is fixed relative to outer electrodes but the central electrode may be adjusted by an attached support altering the chamber dimensions and hence the length of source in each. Also disclosed are a centrally mounted source tiltable towards one or other chamber and a central electrode tiltable to alter chamber dimensions. (U.K.)

Contamination Control Assessment of the World's Largest Space Environment Simulation Chamber

Science.gov (United States)

Snyder, Aaron; Henry, Michael W.; Grisnik, Stanley P.; Sinclair, Stephen M.

2012-01-01

The Space Power Facility s thermal vacuum test chamber is the largest chamber in the world capable of providing an environment for space simulation. To improve performance and meet stringent requirements of a wide customer base, significant modifications were made to the vacuum chamber. These include major changes to the vacuum system and numerous enhancements to the chamber s unique polar crane, with a goal of providing high cleanliness levels. The significance of these changes and modifications are discussed in this paper. In addition, the composition and arrangement of the pumping system and its impact on molecular back-streaming are discussed in detail. Molecular contamination measurements obtained with a TQCM and witness wafers during two recent integrated system tests of the chamber are presented and discussed. Finally, a concluding remarks section is presented.

Simple structure diffusion cloud chamber for educational purpose

International Nuclear Information System (INIS)

Hrehuss, Gy.; Molnar, B.

1982-01-01

A simple structure diffusion cloud chamber was designed and built with educational aim. The source of alpha particles is Am-241 radioisotope smeared on steel foil, the source of vapor is a felt disc saturated with methanol. Five minutes after covering the chamber the system achieves the thermodynamic equilibrium and alpha particle tracks of 5 cm length become visible in the centre of the chamber. Life-time of a track is about 0.5-1 second, the frequency is 2-3 tracks/s. The presented diffusion chamber can be built simply and easily, using cheap common materials and components. (D.Gy.)

Doriot Climatic Chambers

Data.gov (United States)

Federal Laboratory Consortium — The Doriot Climatic Chambers are two, 60-feet long, 11-feet high, 15-feet wide chambers that are owned and operated by NSRDEC. The Doriot Climatic Chambers are among...

A Portable, Low-Power Analyzer and Automated Soil Flux Chamber System for Measuring Wetland GHG Emissions

Science.gov (United States)

Nickerson, Nick; Kim-Hak, David; McArthur, Gordon

2017-04-01

Preservation and restoration of wetlands has the potential to help sequester large amounts of carbon due to the naturally high primary productivity and slow turnover of stored soil carbon. However, the anoxic environmental conditions present in wetland soils are also the largest natural contributor to global methane emissions. While it is well known that wetlands are net carbon sinks over long time scales, given the high global warming potential of methane, the short-term balances between C uptake and storage and loss as CO2 and CH4 need to be carefully considered when evaluating the climate effects of land-use change. It is relatively difficult to measure methane emissions from wetlands with currently available techniques given the temporally and spatially sporadic nature of the processes involved (methanogenesis, methane oxidation, ebullition, etc.). For example, using manual soil flux chambers can often only capture a portion of either the spatial or temporal variability, and often have other disadvantages associated with soil atmosphere disturbance during deployment in these relatively compressible wetland soils. Automated chamber systems offer the advantage of collecting high-resolution time series of gaseous fluxes while reducing some human and method induced biases. Additionally, new laser-based analyzers that can be used in situ alongside automated chambers offer a greater minimum detectable flux than can be achieved using alternative methods such as Gas Chromatography. Until recently these types of automated measurements were limited to areas that had good power coverage, as laser based systems were power intensive and could not easily be supplemented with power from field-available sources such as solar. Recent advances in laser technology has reduced the power needed and made these systems less power intensive and more field portable in the process. Here we present data using an automated chamber system coupled to a portable laser based greenhouse gas

Ionization chamber

International Nuclear Information System (INIS)

1977-01-01

An improved ionization chamber type X-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is placed next to the anode and is maintained at a voltage intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting towards the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

Ultra-low mass drift chambers

Science.gov (United States)

Assiro, R.; Cappelli, L.; Cascella, M.; De Lorenzis, L.; Grancagnolo, F.; Ignatov, F.; L'Erario, A.; Maffezzoli, A.; Miccoli, A.; Onorato, G.; Perillo, M.; Piacentino, G.; Rella, S.; Rossetti, F.; Spedicato, M.; Tassielli, G.; Zavarise, G.

2013-08-01

We present a novel low mass drift chamber concept, developed in order to fulfill the stringent requirements imposed by the experiments for extremely rare processes, which require high resolutions (order of 100-200 keV/c) for particle momenta in a range (50-100 MeV/c) totally dominated by the multiple scattering contribution. We describe a geometry optimization procedure and a new wiring strategy with a feed-through-less wire anchoring system developed and tested on a drift chamber prototype under completion at INFN-Lecce .

Inertial confinement fusion reaction chamber and power conversion system study. Final report

International Nuclear Information System (INIS)

Maya, I.; Schultz, K.R.; Bourque, R.F.

1985-10-01

This report summarizes the results of the second year of a two-year study on the design and evaluation of the Cascade concept as a commercial inertial confinement fusion (ICF) reactor. We developed a reactor design based on the Cascade reaction chamber concept that would be competitive in terms of both capital and operating costs, safe and environmentally acceptable in terms of hazard to the public, occupational exposure and radioactive waste production, and highly efficient. The Cascade reaction chamber is a double-cone-shaped rotating drum. The granulated solid blanket materials inside the rotating chamber are held against the walls by centrifugal force. The fusion energy is captured in a blanket of solid carbon, BeO, and LiAlO 2 granules. These granules are circulated to the primary side of a ceramic heat exchanger. Primary-side granule temperatures range from 1285 K at the LiAlO 2 granule heat exchanger outlet to 1600 K at the carbon granule heat exchanger inlet. The secondary side consists of a closed-cycle gas turbine power conversion system with helium working fluid, operating at 1300 K peak outlet temperature and achieving a thermal power conversion efficiency of 55%. The net plant efficiency is 49%. The reference design is a plant producing 1500 MW of D-T fusion power and delivering 815 MW of electrical power for sale to the utility grid. 88 refs., 44 figs., 47 tabs

OPAL jet chamber full scale prototype

Energy Technology Data Exchange (ETDEWEB)

Fischer, H M; Hauschild, M; Hartmann, H; Hegerath, A; Boerner, H; Burckhart, H J; Dittmar, M; Hammarstreom, R; Heuer, R D; Mazzone, L

1986-05-22

The concept of a jet chamber for the central detector of OPAL has been tested with a full scale prototype. The design of this prototype, its mechanical and electrical structure and its support system for high voltage, gas, laser calibration and readout are described. The operating experience gathered since the summer of 1984 and the chamber performance as measured by its spatial resolution and ability to identify particles are also given.

An improvement study on the closed chamber distillation system for recovery of renewable salts from salt wastes containing radioactive rare earth compounds

International Nuclear Information System (INIS)

Eun, H.C.; Cho, Y.Z.; Lee, T.K.; Kim, I.T.; Park, G.I.; Lee, H.S.

2013-01-01

In this paper, an improvement study on the closed chamber distillation system for recovery of renewable salts from salt wastes containing radioactive rare earth compounds was performed to determine optimum operating conditions. It was very important to maintain the pressure in the distillation chamber below 10 Torr for a high efficiency (salt recovery >99 %) of the salt distillation. This required increasing the salt vaporization and condensation rates in the distillation system. It was confirmed that vaporization and condensation rates could be improved controlling the given temperature of top of the condensation chamber. In the distillation tests of the salt wastes containing rare earth compounds, the operation time at a given temperature was greatly reduced changing the given temperature of top of the condensation chamber from 780 to 700 deg C. (author)

The Liquid Nitrogen System for Chamber A: A Change from Original Forced Flow Design to a Natural Flow (Thermo Siphon) System

Science.gov (United States)

Homan, Jonathan; Montz, Michael; Sidi-Yekhlef, Ahmed; Ganni, Venkatarao (Rao); Knudsen, Peter; Garcia, Sam; Linza, Robert; Meagher, Daniel; Lauterbauch, John

2008-01-01

NASA Johnson Space Center (JSC) in Houston is currently supplementing its 20K helium refrigeration system to meet the new requirements for testing the James Web Space Telescope in the environmental control Chamber-A (65 dia x 120 high) in Building 32. The new system is required to meet the various operating modes which include a high 20K heat load, a required temperature stability at the load, rapid (but controlled) cool down and warm up and bake out of the chamber. This paper will present the proposed modifications to the existing helium system(s) to incorporate the new requirements and the integration of the new helium refrigerator with the existing two 3.5KW 20K helium refrigerators. In addition, the floating pressure process control philosophy to achieve high efficiency over the operating range (40% to 100% of the refrigeration system capacity), and the required temperature stability of +/- 0.25 K at the load will be discussed. The refrigeration systems ability to naturally seek the operating conditions under various loads and thus minimizing operator involvement and the over all improvements to the system operability and the reliability will be explained.

Study of pulp chamber morphology of primary mandibular molars using spiral computed tomography.

Science.gov (United States)

Selvakumar, Haridoss; Kavitha, Swaminathan; Vijayakumar, Rajendran; Eapen, Thomas; Bharathan, Rajendran

2014-11-01

The purpose of this study was to evaluate the pulp chamber morphology in primary mandibular molars using spiral computed tomography (SCT). Sixty extracted primary mandibular molars were scanned using SCT for the (i) distance between the central fissure to furcation, (ii) distance between the central fissure to the floor of the pulp chamber, (iii) height of the pulp chamber (roof-floor), (iv) distance between the floor of the pulp chamber to the furcation. The mean and standard deviation was analyzed using statistical package for the social sciences (SPSS) program. The results of this study show that the average mean distance from the central fissure to the floor of the pulp chamber is 5.07 mm in first mandibular primary molar and 5.54 mm in second mandibular primary molar. It can be concluded that the greatest depth to which a bur can go during access opening without perforating the furcation in first primary mandibular molar is 5.07 mm and 5.54 mm in second primary mandibular molar.

Vacuum chamber-free centrifuge with magnetic bearings.

Science.gov (United States)

Park, Cheol Hoon; Kim, Soohyun; Kim, Kyung-Soo

2013-09-01

Centrifuges are devices that separate particles of different densities and sizes through the application of a centrifugal force. If a centrifuge could be operated under atmospheric conditions, all vacuum-related components such as the vacuum chamber, vacuum pump, diffusion pump, and sealing could be removed from a conventional centrifuge system. The design and manufacturing procedure for centrifuges could then be greatly simplified to facilitate the production of lightweight centrifuge systems of smaller volume. Furthermore, the maintenance costs incurred owing to wear and tear due to conventional ball bearings would be eliminated. In this study, we describe a novel vacuum chamber-free centrifuge supported by magnetic bearings. We demonstrate the feasibility of the vacuum chamber-free centrifuge by presenting experimental results that verify its high-speed support capability and motoring power capacity.

Design of the CLIC Quadrupole Vacuum Chambers

CERN Document Server

Garion, C

2010-01-01

The Compact Linear Collider, under study, requires vacuum chambers with a very small aperture, of the order of 8 mm in diameter, and with a length up to around 2 m for the main beam quadrupoles. To keep the very tight geometrical tolerances on the quadrupoles, no bake out is allowed. The main issue is to reach UHV conditions (typically 10-9 mbar static pressure) in a system where the vacuum performance is driven by water outgassing. For this application, a thinwalled stainless steel vacuum chamber with two ante chambers equipped with NEG strips, is proposed. The mechanical design, especially the stability analysis, is shown. The key technologies of the prototype fabrication are given. Vacuum tests are carried out on the prototypes. The test set-up as well as the pumping system conditions are presented.

Measurement and Compensation of BPM Chamber Motion in HLS

Science.gov (United States)

Li, J. W.; Sun, B. G.; Cao, Y.; Xu, H. L.; Lu, P.; Li, C.; Xuan, K.; Wang, J. G.

2010-06-01

Significant horizontal drifts in the beam orbit in the storage ring of HLS (Hefei Light Source) have been seen for many years. What leads to the motion of Beam Position Monitor (BPM) chamber is thermal expansion mainly caused by the synchrotron light. To monitor the BPM chamber motions for all BPMs, a BPM chamber motion measurement system is built in real-time. The raster gauges are used to measure the displacements. The results distinctly show the relation between the BPM chamber motion and the beam current. To suppress the effect of BPM chamber motion, a compensation strategy is implemented at HLS. The horizontal drifts of beam orbit have been really suppressed within 20μm without the compensation of BPM chamber motion in the runtime.

Measurement and Compensation of BPM Chamber Motion in HLS

International Nuclear Information System (INIS)

Li, J. W.; Sun, B. G.; Cao, Y.; Xu, H. L.; Lu, P.; Li, C.; Xuan, K.; Wang, J. G.

2010-01-01

Significant horizontal drifts in the beam orbit in the storage ring of HLS (Hefei Light Source) have been seen for many years. What leads to the motion of Beam Position Monitor (BPM) chamber is thermal expansion mainly caused by the synchrotron light. To monitor the BPM chamber motions for all BPMs, a BPM chamber motion measurement system is built in real-time. The raster gauges are used to measure the displacements. The results distinctly show the relation between the BPM chamber motion and the beam current. To suppress the effect of BPM chamber motion, a compensation strategy is implemented at HLS. The horizontal drifts of beam orbit have been really suppressed within 20μm without the compensation of BPM chamber motion in the runtime.

Propagation of the trip behavior in the VENUS vertex chamber

International Nuclear Information System (INIS)

Ohama, Taro; Yamada, Yoshikazu.

1995-03-01

The high voltage system of the VENUS vertex chamber occasionally trips by a discharge somewhere among cathode electrodes during data taking. This trip behavior induces often additional trips at other electrodes such as the skin and the grid electrodes in the vertex chamber. This propagation mechanism of trips is so complicated in this system related with multi-electrodes. Although the vertex chamber is already installed inside the VENUS detector and consequently the discharge is not able to observe directly, a trial to estimate the propagation has been done using only the information which appears around the trip circuits and the power supply of the vertex chamber. (author)

COLDDIAG: A Cold Vacuum Chamber for Diagnostics

CERN Document Server

Casalbuoni, S; Gerstl, S; Grau, A W; Hagelstein, M; Saez de Jauregui, D; Boffo, C; Sikler, G; Baglin, V; Cox, M P; Schouten, J C; Cimino, R; Commisso, M; Spataro, B; Mostacci, A; Wallen, E J; Weigel, R; Clarke, J; Scott, D; Bradshaw, T; Jones, R; Shinton, I

2011-01-01

One of the still open issues for the development of superconducting insertion devices is the understanding of the beam heat load. With the aim of measuring the beam heat load to a cold bore and the hope to gain a deeper understanding in the beam heat load mechanisms, a cold vacuum chamber for diagnostics is under construction. The following diagnostics will be implemented: i) retarding field analyzers to measure the electron energy and flux, ii) temperature sensors to measure the total heat load, iii) pressure gauges, iv) and mass spectrometers to measure the gas content. The inner vacuum chamber will be removable in order to test different geometries and materials. This will allow the installation of the cryostat in different synchrotron light sources. COLDDIAG will be built to fit in a short straight section at ANKA. A first installation at the synchrotron light source Diamond is foreseen in June 2011. Here we describe the technical design report of this device and the planned measurements with beam.

Design and tests of the z-coordinate drift chamber system for the OPAL central detector at LEP

International Nuclear Information System (INIS)

Mes, H.; Dixit, M.S.; Godfrey, L.; Hanna, D.; Hargrove, C.K.; Losty, M.J.; Oakham, F.G.; Bavaria, G.; Jeremie, H.; Lessard, L.; Lorazo, B.; Martin, J.P.

1988-01-01

A system of drift chambers has been designed to make high resolution measurements of the z-coordinates of charged tracks at the outer radius of the OPAL central detector at LEP. The unit module of this detector is a 25 cm drift length bidirectional cell with six sense wires in a thin 50 cm wide by 29 mm high drift slot. Tests indicate that the chamber has a wide and stable electric field operating range and its performance is unaffected by small misalignments between the drift electric field and an external magnetic field. The drift cell was found to have uniform acceptance up to its geometrical boundaries, and the z-resolution for beam tracks normal to the chamber was measured to be in the range of 40-175 μm. (orig.)

On the use of unshielded cables in ionization chamber dosimetry for total-skin electron therapy

International Nuclear Information System (INIS)

Zhe Chen; Agostinelli, Alfred; Nath, Ravinder

1998-01-01

The dosimetry of total-skin electron therapy (TSET) usually requires ionization chamber measurements in a large electron beam (up to 120cmx200cm). Exposing the chamber's electric cable, its connector and part of the extension cable to the large electron beam will introduce unwanted electronic signals that may lead to inaccurate dosimetry results. While the best strategy to minimize the cable-induced electronic signal is to shield the cables and its connector from the primary electrons, as has been recommended by the AAPM Task Group Report 23 on TSET, cables without additional shielding are often used in TSET dosimetry measurements for logistic reasons, for example when an automatic scanning dosimetry is used. This paper systematically investigates the consequences and the acceptability of using an unshielded cable in ionization chamber dosimetry in a large TSET electron beam. In this paper, we separate cable-induced signals into two types. The type-I signal includes all charges induced which do not change sign upon switching the chamber polarity, and type II includes all those that do. The type-I signal is easily cancelled by the polarity averaging method. The type-II cable-induced signal is independent of the depth of the chamber in a phantom and its magnitude relative to the true signal determines the acceptability of a cable for use under unshielded conditions. Three different cables were evaluated in two different TSET beams in this investigation. For dosimetry near the depth of maximum buildup, the cable-induced dosimetry error was found to be less than 0.2% when the two-polarity averaging technique was applied. At greater depths, the relative dosimetry error was found to increase at a rate approximately equal to the inverse of the electron depth dose. Since the application of the two-polarity averaging technique requires a constant-irradiation condition, it was demonstrated that an additional error of up to 4% could be introduced if the unshielded cable

Measurements of the drift velocity using a small gas chamber for monitoring of the CMS muon system

CERN Document Server

Frangenheim, J

This diploma thesis presents measurements of the drift velocity of electrons in gas. A small gas detector (VDC1 ) is used. This chamber is intended for measurement and monitoring of the drift velocity in the gas of the muon chambers of the gas detector system in the barrel area of the CMS-detector2 at the European Research Center for Particle Physics CERN near Geneva. The drift velocity is, together with the drift time, a key parameter for measurements with drift chambers. The aim of this thesis is to perform test measurements to determine parameters of the chamber and also to estimate systematic errors. Beside the drift velocity, further parameters of the gas like the pressure and the temperature are measured and accounted for. For the further work with the VDCs, analysis software has been created which is used for the analysis of the measurements. Parallel to this work, necessary improvements, e.g. for the high voltage robustness, were also implemented and tested. In addition, studies and test measurements ...

Chamber and Wall Response to Target Implosion in Inertial and Z-Pinch Fusion and Lithography Devices

International Nuclear Information System (INIS)

Hassanein, A.; Konkashbaev, I.; Morozov, V.; Sizyuk, V.

2006-01-01

The chamber walls, both solid and liquid, in inertial fusion energy (IFE) and Z-pinch reactors and Lithography devices are exposed to harsh conditions following each target implosion or pinching of plasma. Key issues of the cyclic IFE operation include intense photon and ion deposition, wall thermal and hydrodynamic evolution, wall erosion and fatigue lifetime, and chamber clearing and evacuation to ensure desirable conditions prior to target implosion. Detailed models have been developed for reflected laser light, emitted photons, neutrons, and target debris deposition and interaction with chamber components and have been implemented in the comprehensive HEIGHTS software package. The hydrodynamic response of chamber walls in bare or in gas-filled cavities and the photon transport of the deposited energy has been calculated by means of new and advanced numerical techniques for accurate shock treatment and propagation. These models include detail media hydrodynamics, non-LTE multi-group for both continuum and line radiation transport, and dynamics of eroded debris resulting from the intense energy deposition. The focus of this study is to critically assess the reliability and the dynamic response of chamber walls in various proposed protection methods for IFE systems. Key requirements are that: (i) the chamber wall accommodates the cyclic energy deposition while providing the required lifetime due to various erosion mechanisms, such as vaporization, chemical and physical sputtering, melt/liquid splashing and explosive erosion, and fragmentation of liquid walls, and (ii) after each shot the chamber is cleared and returned to a quiescent state in preparation for the target injection and the firing of the driver for the subsequent shot. This paper investigates in details these two important issues and found that the required operating frequency of the IFE reactors for power production may be severely limited due to these two requirements. (author)

The DEIS high energy muon spectrometer. II. The data acquisition system

International Nuclear Information System (INIS)

Allkofer, O.C.; Dau, W.D.; Faehnders, E.; Jokisch, H.; Kaleschke, G.P.; Klemke, G.; Sauerland, K.; Schmidtke, G.; Uhr, R.C.; Bella, G.; Oren, Y.; Virni, U.; Seidman, A.

1977-01-01

The whole spectrometer is read out and controlled on-line via a CAMAC-system by a minicomputer. The magnetostrictive read out signals of 66 magnetostrictive read out wands of the wire spark chambers are digitized by 20-MHz-scalers which can store up to 8 sparks per chamber. The time-of-flight of the muon, the pulse heights of the scintillation counters, the time of event are also recorded. The on-line-computer makes reliability checks of the data and stores them together with monitor data about magnetic field, gas and high voltage system, etc. on magnetic tape for off-line analysis. (author)

Ultra-low mass drift chambers

International Nuclear Information System (INIS)

Assiro, R.; Cappelli, L.; Cascella, M.; De Lorenzis, L.; Grancagnolo, F.; Ignatov, F.; L'Erario, A.; Maffezzoli, A.; Miccoli, A.; Onorato, G.; Perillo, M.; Piacentino, G.; Rella, S.; Rossetti, F.; Spedicato, M.; Tassielli, G.

2013-01-01

We present a novel low mass drift chamber concept, developed in order to fulfill the stringent requirements imposed by the experiments for extremely rare processes, which require high resolutions (order of 100–200 keV/c) for particle momenta in a range (50–100 MeV/c) totally dominated by the multiple scattering contribution. We describe a geometry optimization procedure and a new wiring strategy with a feed-through-less wire anchoring system developed and tested on a drift chamber prototype under completion at INFN-Lecce

Resistive Plate Chambers commissioning and performance results for 2015

CERN Document Server

CMS Collaboration

2016-01-01

The Resistive Plate Chamber (RPC) detector system at the Compact Muon Solenoid experiment at the LHC confers robustness and redundancy to the muon trigger. During the first long shutdown of the LHC (2013-2014) the CMS muon RPC system has been upgraded with 144 double-gap chambers on the forth forward stations. A total of 1056 double-gap chambers cover the pseudo-rapidity region up to 1.6. The main detector parameters are constantly and closely monitored to achieve operational stability and high quality data in the harsh conditions of the second run period of the LHC (13 TeV and 25 ns bunch spacing). Resistive Plate Chambers (RPC) performance results for 2015 with pp collisions at 13 TeV are presented. These results include the occupancy, efficiency of newly installed detectors after applying new working point, history plots for the RPC relevant variables such as: Cluster Size, Efficiency, percentage of inactive detector during operation and Rates and overall system noise. RPC variables are studied as funct...

Plasma chemistry in wire chambers

International Nuclear Information System (INIS)

Wise, J.

1990-05-01

The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an 55 Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed

Influence of the Structure of a Solid-Fuel Mixture on the Thermal Efficiency of the Combustion Chamber of an Engine System

Science.gov (United States)

Futko, S. I.; Koznacheev, I. A.; Ermolaeva, E. M.

2014-11-01

On the basis of thermodynamic calculations, the features of the combustion of a solid-fuel mixture based on the glycidyl azide polymer were investigated, the thermal cycle of the combustion chamber of a model engine system was analyzed, and the efficiency of this chamber was determined for a wide range of pressures in it and different ratios between the components of the combustible mixture. It was established that, when the pressure in the combustion chamber of an engine system increases, two maxima arise successively on the dependence of the thermal efficiency of the chamber on the weight fractions of the components of the combustible mixture and that the first maximum shifts to the side of smaller concentrations of the glycidyl azide polymer with increase in the pressure in the chamber; the position of the second maximum is independent of this pressure, coincides with the minimum on the dependence of the rate of combustion of the mixture, and corresponds to the point of its structural phase transition at which the mole fractions of the carbon and oxygen atoms in the mixture are equal. The results obtained were interpreted on the basis of the Le-Chatelier principle.

Multiwire proportional chamber development

Science.gov (United States)

Doolittle, R. F.; Pollvogt, U.; Eskovitz, A. J.

1973-01-01

The development of large area multiwire proportional chambers, to be used as high resolution spatial detectors in cosmic ray experiments is described. A readout system was developed which uses a directly coupled, lumped element delay-line whose characteristics are independent of the MWPC design. A complete analysis of the delay-line and the readout electronic system shows that a spatial resolution of about 0.1 mm can be reached with the MWPC operating in the strictly proportional region. This was confirmed by measurements with a small MWPC and Fe-55 X-rays. A simplified analysis was carried out to estimate the theoretical limit of spatial resolution due to delta-rays, spread of the discharge along the anode wire, and inclined trajectories. To calculate the gas gain of MWPC's of different geometrical configurations a method was developed which is based on the knowledge of the first Townsend coefficient of the chamber gas.

Carbonylative Heck Reactions Using CO Generated ex Situ in a Two-Chamber System

DEFF Research Database (Denmark)

Hermange, Philippe; Gøgsig, Thomas; Lindhardt, Anders Thyboe

2011-01-01

A carbonylative Heck reaction of aryl iodides and styrene derivatives employing a two-chamber system using a stable, crystalline, and nontransition metal based carbon monoxide source is reported. By applying near-stoichiometric amounts of the carbon monoxide precursor, an effective exploitation o...... of the hazardous CO gas is obtained affording chalcone derivatives in good yields. Application to isotope labeling, incorporating 13CO, was further established....

The wide gap resistive plate chamber

International Nuclear Information System (INIS)

Crotty, I.; Lamas Valverde, J.; Hatzifotiadou, D.; Williams, M.C.S.; Zichichi, A.

1995-01-01

The resistive plate chamber (RPC) has good time and position resolution; these factors (coupled to its simple construction) make it an attractive candidate for muon trigger systems at future colliders. However, operated in spark mode, the RPC has severe rate problems that make it unusable above 10 Hz/cm 2 . We have previously published our results concerning the operation of the RPC in spark and in avalanche mode; we have shown that the rate limit can be increased to 150 Hz/cm 2 if the RPC is operated in avalanche mode. Here, we discuss the performance of chambers with 6 and 8 mm gas gaps (compared to the more usual 2 mm gap). We outline the reasons for this choice, and also discuss anode versus cathode strip readout. We have measured the efficiency versus flux, and also show that an enhanced rate limit can be obtained if only a small region of the chamber is exposed to the beam (spot illumination). Finally we have tested the performance of chambers constructed with other materials for the resistiv e plate and compare it to chambers constructed with our preferred plastic, melamine laminate. (orig.)

Climate chamber for environmentally controlled laboratory airflow experiments.

Science.gov (United States)

Even-Tzur, Nurit; Zaretsky, Uri; Grinberg, Orly; Davidovich, Tomer; Kloog, Yoel; Wolf, Michael; Elad, David

2010-01-01

Climate chambers have been widely used in in vitro and in vivo studies which require controlled environmental temperature and humidity conditions. This article describes a new desktop climate chamber that was developed for application of respiratory airflows on cultured nasal epithelial cells (NEC) under controlled temperature and humidity conditions. Flow experiments were performed by connecting the climate chamber to an airflow generator via a flow chamber with cultured NEC. Experiments at two controlled climate conditions, 25 degrees C and 40% relative humidity (RH) and 37 degrees C and 80%RH, were conducted to study mucin secretion from the cultures inresponse to the flow. The new climate chamber is a relatively simple and inexpensive apparatus which can easily be connected to any flow system for climate controlled flow experiments. This chamber can be easily adjusted to various in vitro experiments, as well as to clinical studies with animals or human subjects which require controlled climate conditions.

PEP-II RF System Operation and Performance

International Nuclear Information System (INIS)

McIntosh, P.

2005-01-01

The Low Energy Ring (LER) and High Energy Ring (HER) RF systems have operated now on PEP-II since July 1998 and have assisted in breaking all design luminosity records back in June 2001. Luminosity on PEP-II has steadily increased since then as a consequence of larger e+ and e- beam currents being accumulated. This has meant that the RF systems have inevitably been driven harder, not only to achieve these higher stored beam currents, but also to reliably keep the beams circulating whilst at the same time minimizing the number of aborts due to RF system faults. This paper details the current PEP-II RF system configurations for both rings, as well as future upgrade plans spanning the next 3-5 years. Limitations of the current RF system configurations are presented, highlighting improvement projects which will target specific areas within the RF systems to ensure that adequate operating overheads are maintained and reliable operation is assured. The Low Energy Ring (LER) and High Energy Ring (HER) RF systems have operated now on PEP-II since July 1998 and have assisted in breaking all design luminosity records back in June 2001. Luminosity on PEP-II has steadily increased since then as a consequence of larger e+ and e- beam currents being accumulated. This has meant that the RF systems have inevitably been driven harder, not only to achieve these higher stored beam currents, but also to reliably keep the beams circulating whilst at the same time minimizing the number of aborts due to RF system faults. This paper details the current PEP-II RF system configurations for both rings, as well as future upgrade plans spanning the next 3-5 years. Limitations of the current RF system configurations are presented, highlighting improvement projects which will target specific areas within the RF systems to ensure that adequate operating overheads are maintained and reliable operation is assured

Herds of methane chambers grazing bubbles

Science.gov (United States)

Grinham, Alistair; Dunbabin, Matthew

2014-05-01

Water to air methane emissions from freshwater reservoirs can be dominated by sediment bubbling (ebullitive) events. Previous work to quantify methane bubbling from a number of Australian sub-tropical reservoirs has shown that this can contribute as much as 95% of total emissions. These bubbling events are controlled by a variety of different factors including water depth, surface and internal waves, wind seiching, atmospheric pressure changes and water levels changes. Key to quantifying the magnitude of this emission pathway is estimating both the bubbling rate as well as the areal extent of bubbling. Both bubbling rate and areal extent are seldom constant and require persistent monitoring over extended time periods before true estimates can be generated. In this paper we present a novel system for persistent monitoring of both bubbling rate and areal extent using multiple robotic surface chambers and adaptive sampling (grazing) algorithms to automate the quantification process. Individual chambers are self-propelled and guided and communicate between each other without the need for supervised control. They can maintain station at a sampling site for a desired incubation period and continuously monitor, record and report fluxes during the incubation. To exploit the methane sensor detection capabilities, the chamber can be automatically lowered to decrease the head-space and increase concentration. The grazing algorithms assign a hierarchical order to chambers within a preselected zone. Chambers then converge on the individual recording the highest 15 minute bubbling rate. Individuals maintain a specified distance apart from each other during each sampling period before all individuals are then required to move to different locations based on a sampling algorithm (systematic or adaptive) exploiting prior measurements. This system has been field tested on a large-scale subtropical reservoir, Little Nerang Dam, and over monthly timescales. Using this technique

SU-E-T-228: Liquid Ionisation Chamber Array and MicroDiamond Measurements with the CyberKnife System

International Nuclear Information System (INIS)

Poppinga, D; Looe, H; Stelljes, T; Poppe, B; Blanck, O; Harder, D

2014-01-01

Purpose: The aim of this study was to measure the dose profile and output factors with a CyberKnife accelerator using a TM60019 microDiamond detector and a 1000SRS liquid chamber array (both PTW Freiburg, Germany). Methods: An MP3 water phantom (PTW, Freiburg) was positioned along the robotic world coordinate system. The TM60019 detector was adjusted to the center of the according fields and the semiconductor axis was aligned with the beam direction. Profiles at 5cm water depth and SSD = 80 cm were measured along the robotic x axis and y axis for the cylindrical collimators of the CyberKnife (diameter 60, 50, 40, 30, 20, 15, 12.5, 10, 7.5 and 5mm). To determine the output factors the dose profile was measured at 0.1 mm steps around the field center to find the maximum dose value. The liquid chamber array (1000SRS) measurement was performed with the same setup, but with RW3 buildup. Results: The 1000SRS measurements closely conform with the TM60019 profile measurement in all profile regions and for all collimator sizes. The profile measurement is influenced by the almost equal spatial resolution of the TM60019 detector (radius of the sensitive area 1.1mm) and of the 1000SRS liquid chamber array (single chamber width 2.3mm). The measured dose profiles have not been corrected for this limited spatial resolution. Rather we purpose to consider that spatial dose averaging over 2 mm wide regions might be justified in view of patient positioning inaccuracies and of the spaces in tissue participating in the biological radiation responses. Conclusion: The 1000SRS data points conform with the TM60019 profile measurements at all profile regions showing the applicability of liquid ion chamber arrays with the CyberKnife system

SU-E-T-228: Liquid Ionisation Chamber Array and MicroDiamond Measurements with the CyberKnife System

Energy Technology Data Exchange (ETDEWEB)

Poppinga, D; Looe, H; Stelljes, T; Poppe, B [University of Oldenburg, Oldenburg, Lower Saxony (Germany); Blanck, O [CyberKnife Zentrum Norddeutschland, Guestrow (Germany); Harder, D [Georg August University, Goettingen, Niedersachsen (Germany)

2014-06-01

Purpose: The aim of this study was to measure the dose profile and output factors with a CyberKnife accelerator using a TM60019 microDiamond detector and a 1000SRS liquid chamber array (both PTW Freiburg, Germany). Methods: An MP3 water phantom (PTW, Freiburg) was positioned along the robotic world coordinate system. The TM60019 detector was adjusted to the center of the according fields and the semiconductor axis was aligned with the beam direction. Profiles at 5cm water depth and SSD = 80 cm were measured along the robotic x axis and y axis for the cylindrical collimators of the CyberKnife (diameter 60, 50, 40, 30, 20, 15, 12.5, 10, 7.5 and 5mm). To determine the output factors the dose profile was measured at 0.1 mm steps around the field center to find the maximum dose value. The liquid chamber array (1000SRS) measurement was performed with the same setup, but with RW3 buildup. Results: The 1000SRS measurements closely conform with the TM60019 profile measurement in all profile regions and for all collimator sizes. The profile measurement is influenced by the almost equal spatial resolution of the TM60019 detector (radius of the sensitive area 1.1mm) and of the 1000SRS liquid chamber array (single chamber width 2.3mm). The measured dose profiles have not been corrected for this limited spatial resolution. Rather we purpose to consider that spatial dose averaging over 2 mm wide regions might be justified in view of patient positioning inaccuracies and of the spaces in tissue participating in the biological radiation responses. Conclusion: The 1000SRS data points conform with the TM60019 profile measurements at all profile regions showing the applicability of liquid ion chamber arrays with the CyberKnife system.

Integrated Chamber Design for the Laser Inertial Fusion Energy (LIFE) Engine

International Nuclear Information System (INIS)

Latkowski, J.F.; Kramer, K.J.; Abbott, R.P.; Morris, K.R.; DeMuth, J.; Divol, L.; El-Dasher, B.; Lafuente, A.; Loosmore, G.; Reyes, S.; Moses, G.A.; Fratoni, M.; Flowers, D.; Aceves, S.; Rhodes, M.; Kane, J.; Scott, H.; Kramer, R.; Pantano, C.; Scullard, C.; Sawicki, R.; Wilks, S.; Mehl, M.

2010-01-01

The Laser Inertial Fusion Energy (LIFE) concept is being designed to operate as either a pure fusion or hybrid fusion-fission system. A key component of a LIFE engine is the fusion chamber subsystem. The present work details the chamber design for the pure fusion option. The fusion chamber consists of the first wall and blanket. This integrated system must absorb the fusion energy, produce fusion fuel to replace that burned in previous targets, and enable both target and laser beam transport to the ignition point. The chamber system also must mitigate target emissions, including ions, x-rays and neutrons and reset itself to enable operation at 10-15 Hz. Finally, the chamber must offer a high level of availability, which implies both a reasonable lifetime and the ability to rapidly replace damaged components. An integrated LIFE design that meets all of these requirements is described herein.

Integrated Chamber Design for the Laser Inertial Fusion Energy (LIFE) Engine

Energy Technology Data Exchange (ETDEWEB)

Latkowski, J F; Kramer, K J; Abbott, R P; Morris, K R; DeMuth, J; Divol, L; El-Dasher, B; Lafuente, A; Loosmore, G; Reyes, S; Moses, G A; Fratoni, M; Flowers, D; Aceves, S; Rhodes, M; Kane, J; Scott, H; Kramer, R; Pantano, C; Scullard, C; Sawicki, R; Wilks, S; Mehl, M

2010-12-07

The Laser Inertial Fusion Energy (LIFE) concept is being designed to operate as either a pure fusion or hybrid fusion-fission system. A key component of a LIFE engine is the fusion chamber subsystem. The present work details the chamber design for the pure fusion option. The fusion chamber consists of the first wall and blanket. This integrated system must absorb the fusion energy, produce fusion fuel to replace that burned in previous targets, and enable both target and laser beam transport to the ignition point. The chamber system also must mitigate target emissions, including ions, x-rays and neutrons and reset itself to enable operation at 10-15 Hz. Finally, the chamber must offer a high level of availability, which implies both a reasonable lifetime and the ability to rapidly replace damaged components. An integrated LIFE design that meets all of these requirements is described herein.

The PEP II injection kicker system

International Nuclear Information System (INIS)

Pappas, G.C.; Donaldson, A.R.; Williams, D.

1997-07-01

PEP II or the B Factory consists of two asymmetric storage rings. The injection energy for electrons is 9 GeV, while that for positrons is 3.1 GeV. The bend angle into the high energy ring (HER) is 0.35 m-rad, and the angle into the low energy ring (LER) is 0.575 m-rad. The magnetic length for the HER kicker is 0.85 m, and 0.55 m for the LER kicker. The field produced by the magnet is therefore 123.5 G for the HER, and 132 G for the LER. Each ring has a kicker magnet upstream of the injection line which is used to distort the orbit of the stored beam. An identical magnet downstream of the injection line is used to restore the orbit of the stored beam and inject the incoming beam. The two magnets are driven in parallel by the modulator. The apeture of the magnets is 3.86x3.46 cm (HxV). Therefore the current required to drive the HER is 863 A, while for the LER it is 756 A. The inductance of the magnet is approximately 1.4 uH/m. The current pulse is a critically damped sinusoid with a rise time of less than 300 ns. A kicker system has been designed which can be used for injection of both beams by varying the charge of voltage. The modulator uses a conjugate circuit to match the impedance of the magnet, and coupling to the beam chamber

Nuclear design considerations for Z-IFE chambers

Energy Technology Data Exchange (ETDEWEB)

Meier, W.R. [Lawrence Livermore National Laboratory, P.O. Box 808, L-641, Livermore, CA 94551 (United States)]. E-mail: meier5@llnl.gov; Schmitt, R.C. [Bettis Atomic Power Laboratory, Pittsburgh, PA 15203 (United States); Abbott, R.P. [Lawrence Livermore National Laboratory, P.O. Box 808, L-641, Livermore, CA 94551 (United States); Latkowski, J.F. [Lawrence Livermore National Laboratory, P.O. Box 808, L-641, Livermore, CA 94551 (United States); Reyes, S. [Lawrence Livermore National Laboratory, P.O. Box 808, L-641, Livermore, CA 94551 (United States)

2006-02-15

Z-pinch driven IFE (Z-IFE) requires the design of a repetitive target insertion system that allows coupling of the pulsed power to the target with adequate standoff, and a chamber that can withstand blast and radiation effects from large yield targets. The present strategy for Z-IFE is to use high yield targets ({approx}2-3 GJ/shot), low repetition rate per chamber ({approx}0.1 Hz), and 10 chambers per power plant. In this study, we propose an alternative power plant configuration that uses very high yield targets (20 GJ/shot) in a single chamber operating at 0.1 Hz. A thick-liquid-wall chamber is proposed to absorb the target emission (X-rays, debris and neutrons) and mitigate the blast effects on the chamber wall. The target is attached to the end of a conical shaped recyclable transmission line (RTL) made from a solid coolant (e.g., frozen flibe), or a material that is easily separable from the coolant (e.g., steel). The RTL/target assembly is inserted through a single opening at the top of the chamber for each shot. This study looks at the RTL material choice from a safety and environmental point of view. Materials were assessed according to waste disposal rating (WDR) and contact dose rate (CDR). Neutronics calculations, using the TART2002 Monte Carlo code from Lawrence Livermore National Laboratory (LLNL), were performed for the RTL and Z-IFE chamber, and key results reported here.

A Radio Frequency Radiation Exposure System for Rodents based on Reverberation Chambers.

Science.gov (United States)

Capstick, Myles; Kuster, Niels; Kuehn, Sven; Berdinas-Torres, Veronica; Gong, Yijian; Wilson, Perry; Ladbury, John; Koepke, Galen; McCormick, David L; Gauger, James; Melnick, Ronald L

2017-08-01

In this paper we present the novel design features, their technical implementation, and an evaluation of the radio Frequency (RF) exposure systems developed for the National Toxicology Program (NTP) of the National Institute of Environmental Health Sciences (NIEHS) studies on the potential toxicity and carcinogenicity of 2nd and 3rd generation mobile-phone signals. The system requirements for this 2-year NTP cancer bioassay study were the tightly-controlled lifetime exposure of rodents (1568 rats and 1512 mice) to three power levels plus sham simulating typical daily, and higher, exposures of users of GSM and CDMA (IS95) signals. Reverberation chambers and animal housing were designed to allow extended exposure time per day for free-roaming individually-housed animals. The performance of the chamber was characterized in terms of homogeneity, stirred to unstirred energy, efficiency. The achieved homogeneity was 0.59 dB and 0.48 dB at 900 and 1900 MHz respectively. The temporal variation in the electric field strength was optimized to give similar characteristics to that of the power control of a phone in a real network using the two stirrers. Experimental dosimetry was performed to validate the SAR sensitivity and determine the SAR uniformity throughout the exposure volume; SAR uniformities of 0.46 dB and 0.40 dB, respectively, for rats and mice were achieved.

A pressurized ion chamber monitoring system for environmental radiation measurements utilizing a wide-range temperature-compensated electrometer

International Nuclear Information System (INIS)

Stevenick, W. Van

1994-01-01

The performance of a complete pressurized ion chamber (PIC) radiation monitoring system is described. The design incorporates an improved temperature-compensated electrometer which is stable to ±3 · 10 -16 A over the environmental range of temperature (-40 to +40 C). Using a single 10 11 Ω feed-back resistor, the electrometer accurately measures currents over a range from 3 · 10 -15 A to 3 · 10 -11 A. While retaining the sensitivity of the original PIC system (the instrument responds readily to small background fluctuations on the order of 0.1 μR h -1 ), the new system measures radiation levels up to the point where the collection efficiency of the ion chamber begins to drop off, typically ∼27 pA at 1 mR h -1 . A data recorder and system controller was designed using the Tattletale trademark Model 4A computer. Digital data is stored on removable solid-state, credit-card style memory cards

The construction technique of the high granularity and high transparency drift chamber of MEG II

Science.gov (United States)

Chiarello, G.; Chiri, C.; Corvaglia, A.; Grancagnolo, F.; Miccoli, A.; Panareo, M.; Pinto, C.; Spedicato, M.; Tassielli, G. F.

2017-07-01

The MEG experiment searches for the charged lepton flavor violating decay, μ +→ e+γ. MEG has already determined the world best upper limit on the branching ratio BRdevelop new wiring strategies. The number of wires and the stringent requirements on the precision of their position and on the uniformity of the wire mechanical tension impose the use of an automatic system to operate the wiring procedures. This wiring robot, designed and built at the INFN Lecce and University of Salento laboratories, consists of: ṡ a semiautomatic wiring machine with a high precision on wire mechanical tensioning (better than 0.5 g) and on wire positioning (20 μ m) for simultaneous wiring of multiwire layers; ṡ a contact-less infrared laser soldering tool; ṡ an automatic handling system for storing and transporting the multi-wire layers. The drift chamber is currently under construction at INFN and should be completed by the end of summer 2017 to be then delivered to PSI for commissioning.

Optimization of combustion chamber geometry for natural gas engines with diesel micro-pilot-induced ignition

International Nuclear Information System (INIS)

Wang, Bin; Li, Tie; Ge, Linlin; Ogawa, Hideyuki

2016-01-01

Highlights: • Combustion chamber geometry is optimized to reduce the HC/CO emissions. • CFD model is calibrated against the spray visualization and engine bench test data. • Design space is explored by the multi-objective NSGA-II with Kriging meta-model. • HC and CO emissions are respectively reduced by 56.47% and 33.55%. - Abstract: Smokeless, low nitrogen oxides (NOx), and high thermal efficiency have been achieved through the lean-burn concept for natural gas engine with diesel micro-pilot-induced ignition (MPII). However, the combustion chamber is usually not specialized for natural gas combustion, and increases in the unburned hydrocarbon (HC) and carbon monoxide (CO) emissions are still a challenge for this type of engines. This paper describes optimization of the combustion chamber geometry to reduce the HC and CO emissions and improve the combustion efficiency in the MPII natural gas engine. The 3-D computational fluid dynamics (CFD) simulation model coupled with a chemical reaction mechanism is described. The temporal development of the short-pulsed diesel spray in a high pressure constant-volume vessel is measured and used to calibrate the spray model in the CFD simulation. The simulation models are validated by the experimental data of the in-cylinder pressure trace, apparent heat release rate (AHRR) and exhaust gas emissions from a single-cylinder MPII natural gas engine. To generate the various combustion chamber geometries, the bowl outline is parameterized by the two cubic Bezier curves while keeping the compression ratio constant. The available design space is explored by the multi-objective non-dominated sorting genetic algorithm II (NSGA-II) with Kriging-based meta-model. With the optimization, the HC and CO emissions are reduced by 56.47% and 33.55%, respectively, while the NOx emissions, the maximum rate of pressure rise and the gross indicated thermal efficiency that are employed as the constraints are slightly improved. Finally, the

Embedded computer systems for control applications in EBR-II

International Nuclear Information System (INIS)

Carlson, R.B.; Start, S.E.

1993-01-01

The purpose of this paper is to describe the embedded computer systems approach taken at Experimental Breeder Reactor II (EBR-II) for non-safety related systems. The hardware and software structures for typical embedded systems are presented The embedded systems development process is described. Three examples are given which illustrate typical embedded computer applications in EBR-II

Components for containment enclosures - Part 3: Transfer systems such as plain doors, airlock chambers, double door transfer systems, leaktight connections for waste drums. 1. ed.

International Nuclear Information System (INIS)

1998-01-01

This part of ISO 11933 specifies requirements for the selection, construction and use of the following leak tight components: doors, airlock chambers, double door transfer systems, leaktight connections for waste drums. Some of the elements, double doors or airlock chambers are described in ISO 11933-1 and ISO 11933-2 as well. Doors having bigger dimensions used for personnel od larger objects are not covered by this document

UHV testing of upgraded vacuum chambers for Indus-1

International Nuclear Information System (INIS)

Sindal, B.K.; Kumar, K.V.A.N.P.S.; Ramshiroman; Bhange, Nilesh; Yadav, D.P.; Sridhar, R.; Shukla, S.K.

2013-01-01

Indus-1 is a 450 MeV, 100 mA dedicated electron storage ring operating at pressure 10 -10 mbar range without beam and 10 -9 mbar range with beam using triode sputter ion pump (SIP) and titanium sublimation pump (TSP) combination. Indus-1 storage ring is presently working with six operational beam lines installed at three bending magnets. To accommodate two more beam lines and to reduce number of demountable joints, up-gradation of Indus-1 UHV system was planned. Salient features of upgraded vacuum system are bending magnet vacuum chambers with one extra port for additional beam line and straight section vacuum chambers with integrated TSP body. Half of the Indus-1 storage ring vacuum envelope with two bending magnet vacuum chamber and six straight section vacuum chambers were assembled with pumps, gauges etc, leak tested and tested for its UHV performance. Ultimate vacuum 5x10 -10 mbar with SIP and 2x10 -10 mbar after TSP pumping were achieved. Residual gas analyser (RGA) spectrum recorded for residual gas analysis indicated the imprints of a typical all metal UHV system having H 2 as major gas. This paper describes UHV testing of upgraded, newly fabricated vacuum chambers for Indus-1 storage ring. (author)

An examination of medical linear accelerator ion-chamber performance

International Nuclear Information System (INIS)

Karolis, C.; Lee, C.; Rinks, A.

1996-01-01

Full text: The company ( Radiation Oncology Physics and Engineering Services Pty Ltd) provides medical physics services to four radiotherapy centres in NSW with a total of 6 high energy medical linear accelerators manufactured by three different companies. As part of the services, the stability of the accelerator ion chamber system is regularly examined for constancy and periodically for absolute calibration. Each accelerator ion chamber has exhibited undesirable behaviour from time to time, sometimes leading to its replacement. This presentation describes the performance of the ion chambers for some of the linacs over a period of 12-18 months and the steps taken by the manufacturer to address the problems encountered. As part of our commissioning procedure of new linacs, an absolute calibration of the accelerator output (photon and electron beams) is repeated several times over the period following examination of the physical properties of the radiation beams. These calibrations were undertaken in water using the groups calibrated ion chamber/electrometer system and were accompanied by constancy checks using an acrylic phantom and field instruments. Constancy checks were performed daily for a period of 8 weeks during the initial life of the accelerator and thereafter weekly. For one accelerator, the ion chamber was replaced 6 times in the first eighteen months of its life due to severe drifts in output, found to be due to pressure changes in one half of the chamber In another accelerator, erratic swings of 2% were observed for a period of nine months, particularly with the electron beams, before the manufacturer offered to change the chamber with another constructed from different materials. In yet another accelerator the ion chamber has shown consistent erratic behaviour, but this has not been addressed by the manufacturer. In another popular accelerator, the dosimetry was found to be very stable until some changes in the tuning were introduced resulting in small

Dual ionization chamber

International Nuclear Information System (INIS)

Mallory, J.; Turlej, Z.

1981-01-01

Dual ionization chambers are provided for use with an electronic smoke detector. The chambers are separated by electrically-conductive partition. A single radiation source extends through the partition into both chambers, ionizing the air in each. The mid-point current of the device may be balanced by adjusting the position of the source

The Role of Second Chambers in the Polish and Romanian Political Systems

Directory of Open Access Journals (Sweden)

Dario Čepo

2007-01-01

Full Text Available The paper outlines the development of bicameral legislatures, distinguishing between the British and American model of bicameralism. It also seeks to demonstrate the power of second chambers based on the difference between the unitary and federal states, presenting Arend Lijphart’s tipology of bicameral legislatures. Moreover, it tries to give a brief outline of the bicameral-unicameral dichotomy in Central and Eastern Europe, and show the questionable legitimacy of second chambers in unitary countries. Using the Senates in Poland and Romania as illustrations, it seeks to highlight their dissimilar historical-institutional development, the differences in their powers and operation and their relationship with first chambers. It also seeks to assign both Senates typologically to one of Lijphart’s four bicameral types, using six relevant variables and highlighting the main difference because of which the Polish Senate is subordinated and the Romanian Senate is equal to the first chamber.

Biochar application reduce ammonia volatilization in a soil-plant system: A closed chamber experiment

Science.gov (United States)

Mandal, Sanchita; Donner, Erica; Smith, Euan; Lombi, Enzo

2017-04-01

Ammonia (NH3) volatilization is considered as one of the major mechanisms responsible for the loss of nitrogen (N) from soil-plant systems worldwide. About 10-30% of N can be lost as NH3 volatilization, which constitutes a significant economic loss. In recent years carbon-based materials such as biochar have created a great research interest because of their ability to increase soil fertility by reducing nutrient loss and pollutants bioavailability in soil. Most of the studies so far have investigated how biochar addition can reduce NH3 volatilization from soils but less information is available for soil-plant systems. In this research, wheat plants (Triticum aestivum, variety: Calingiri) were grown in a calcareous soil (pH 8, calcarosol) inside a closed chamber system to assess both ammonia volatilization and plant N uptake. In this specialized glass chamber air was passed through an inlet where the flow rate was maintained using an air pump (3.5 L min-1). The air outlet was passed through a sulphuric acid trap which was used to capture the volatilized NH3 from the chamber. Plants were watered using the inlet to maintain 50% field capacity throughout the incubation. Two different biochar samples were used in this study: a poultry manure biochar (PM-BC) and a green waste compost biochar (GW-BC) produced at 250 ˚C. Five different application rates were tested (0, 0.5, 1, 1.5, and 2%). The soil was mixed with biochar samples, water, N, P, K, Ca, Mg, and S for one week before sowing. After one week of germination, plants were transferred to the chamber for further three weeks incubation for NH3 volatilization measurement. The study identified that biochar application reduced the NH3 volatilization and increase the plant biomass. Biochar application at 0.5 and 2% decreased the NH3 volatilization by 36 and 48% respectively. The N uptake of the plants also increased from 2.9 to 28% at 0.5 and 2% application rates respectively. The dry biomass of the plant also increased

Neuroprotective Effects and Mechanisms of Curcumin-Cu(II) and -Zn(II) Complexes Systems and Their Pharmacological Implications.

Science.gov (United States)

Yan, Fa-Shun; Sun, Jian-Long; Xie, Wen-Hai; Shen, Liang; Ji, Hong-Fang

2017-12-28

Alzheimer's disease (AD) is the main form of dementia and has a steadily increasing prevalence. As both oxidative stress and metal homeostasis are involved in the pathogenesis of AD, it would be interesting to develop a dual function agent, targeting the two factors. Curcumin, a natural compound isolated from the rhizome of Curcuma longa , is an antioxidant and can also chelate metal ions. Whether the complexes of curcumin with metal ions possess neuroprotective effects has not been evaluated. Therefore, the present study was designed to investigate the protective effects of the complexes of curcumin with Cu(II) or Zn(II) on hydrogen peroxide (H₂O₂)-induced injury and the underlying molecular mechanisms. The use of rat pheochromocytoma (PC12) cells, a widely used neuronal cell model system, was adopted. It was revealed that curcumin-Cu(II) complexes systems possessed enhanced O₂ ·- -scavenging activities compared to unchelated curcumin. In comparison with unchelated curcumin, the protective effects of curcumin-Cu(II) complexes systems were stronger than curcumin-Zn(II) system. Curcumin-Cu(II) or -Zn(II) complexes systems significantly enhanced the superoxide dismutase, catalase, and glutathione peroxidase activities and attenuated the increase of malondialdehyde levels and caspase-3 and caspase-9 activities, in a dose-dependent manner. The curcumin-Cu(II) complex system with a 2:1 ratio exhibited the most significant effect. Further mechanistic study demonstrated that curcumin-Cu(II) or -Zn(II) complexes systems inhibited cell apoptosis via downregulating the nuclear factor κB (NF-κB) pathway and upregulating Bcl-2/Bax pathway. In summary, the present study found that curcumin-Cu(II) or -Zn(II) complexes systems, especially the former, possess significant neuroprotective effects, which indicates the potential advantage of curcumin as a promising agent against AD and deserves further study.

Expert System for the LHC CMS Cathode Strip Chambers (CSC) detector

Energy Technology Data Exchange (ETDEWEB)

Rapsevicius, Valdas, E-mail: valdas.rapsevicius@cern.ch [Fermi National Accelerator Laboratory, Batavia, IL (United States); Vilnius University, Didlaukio g. 47-325, LT-08303 Vilnius (Lithuania); Juska, Evaldas, E-mail: evaldas.juska@cern.ch [Fermi National Accelerator Laboratory, Batavia, IL (United States)

2014-02-21

Modern High Energy Physics experiments are of high demand for a generic and consolidated solution to integrate and process high frequency data streams by applying experts' knowledge and inventory configurations. In this paper we present the Expert System application that was built for the Compact Muon Solenoid (CMS) Cathode Strip Chambers (CSC) detector at the Large Hadron Collider (LHC) aiming to support the detector operations and to provide integrated monitoring. The main building blocks are the integration platform, rule-based complex event processing engine, ontology-based knowledge base, persistent storage and user interfaces for results and control.

HF production in CMS-Resistive Plate Chambers

International Nuclear Information System (INIS)

Abbrescia, M.; Colaleo, A.; Guida, R.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Trentadue, R.; Cavallo, N.; Fabozzi, F.; Paolucci, P.; Piccolo, D.; Polese, G.; Sciacca, C.; Belli, G.; Necchi, M.; Ratti, S.; Riccardi, C.; Torre, P.; Vitulo, P.; Anguelov, T.; Genchev, V.; Panev, B.; Piperov, S.; Sultanov, G.; Vankov, P.; Litov, L.; Pavlov, B.; Petkov, P.

2006-01-01

The formation of highly reactive compounds in the gas mixture during Resistive Plate Chambers (RPCs) operation at the CERN Gamma Irradiation Facility (GIF) is studied. Results from two different types of chambers are discussed: 50 x 50 cm 2 RPC prototypes and two final CMS-RB1 chambers. The RB1 detectors were also connected to a closed loop gas system. Gas composition, possible additional impurities as well as fluoride ions have been monitored in different gamma irradiation conditions both in open and closed loop mode. The chemical composition of the RPC electrode surface has also been analyzed using an electron microscope equipped with an EDS/X-ray

Ionization chamber correction factors for MR-linacs.

Science.gov (United States)

Pojtinger, Stefan; Dohm, Oliver Steffen; Kapsch, Ralf-Peter; Thorwarth, Daniela

2018-06-07

Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B . The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0-2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

Ionization chamber correction factors for MR-linacs

Science.gov (United States)

Pojtinger, Stefan; Steffen Dohm, Oliver; Kapsch, Ralf-Peter; Thorwarth, Daniela

2018-06-01

Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B. The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0–2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

Precision Radio Frequency Anechoic Chamber Facility

Data.gov (United States)

Federal Laboratory Consortium — FUNCTION: Performs measurements and calibration of antennas for satellites and aircraft or groundbased systems. The chamber is primarily used for optimizing antenna...

One cubic metre NIST traceable radon test chamber

International Nuclear Information System (INIS)

Kotrappa, P.; Stieff, F.

2008-01-01

With the availability of the National Inst. of Standards and Technology (NIST) Radon Emanation Standard with a content of ∼5000 Bq of 226 Ra, it is possible to build a flow through a practical radon test chamber. A standard glove box with four gloves and a transfer port is used. Air is pumped through a flow integrator, water jar for humidification and NIST source holder, and into the glove box through a manifold. A derived theoretical expression provides the calculated radon concentration inside the chamber. The calculation includes a derived decay correction due to the large volume and low flow rate of the system. Several calibrated continuous radon monitors and passive integrating electret ion chambers tested in the chamber agreed fairly well with the calculated radon concentrations. The chamber is suitable for handling the calibration of several detectors at the same time. (authors)

Study of new rubber to steel adhesive systems based on Co(II and Cu(II sulphides coats

Directory of Open Access Journals (Sweden)

Labaj Ivan

2018-01-01

Full Text Available The presented paper deals with the preparation of new rubber to steel adhesive systems using the steel surface treatment with deposition of adhesive coats based on Co(II and Cu(II sulphides. Efficiency of new prepared adhesive systems containing Co(II and Cu(II sulphides has been compared with the efficiency of double layer adhesive system commonly used in industry. The chemical composition of prepared adhesive systems was determined using the EDX analysis. Scanning Electron Microscopy (SEM was used for study of topography and microstructure of prepared rubber to steel adhesive systems (Co(II, Cu(II sulphide, double layer adhesive system. For determination of adhesion strength between rubber blends and metal pieces with various adhesive systems deposited on these pieces, the test according to ASTM D429 standard relating to Rubber to metal adhesion, method A was used. For all test samples, the same type of rubber blend and the same curing conditions have been used.

Status of the construction of the KLOE Drift Chamber

International Nuclear Information System (INIS)

Dell'Agnello, S.

1997-01-01

A status report on the construction of the drift chamber for the KLOE experiment at the LNF DAΦNE Φ-factory is given. Physics requirements, detector design performance and its key mechanical features and components are briefly reviewed. The program currently consists of (i) the preparation of final detector components, complemented by (ii) extensive tests of prototypes of critical mechanical parts (like the end plates) and the ''test construction'' of a 1:1 chamber prototype. These two sub-programs are pursued in parallel. Single-component prototype checks include surveys of their shape and size, of accuracy of wire-hole drilling, measurements of their displacement or buckling under nominal load. The ''test construction'' is the debugging of mechanical assembly, survey and alignment of mechanics and of wire-stringing robotics, the actual stringing of a sample 2000 holes drilled on the prototype end plates, the measurement of electrical properties of strung wires, as well as of their mechanical tension. These extensive tests have been successfully completed; they represent an effective hands-on training of the construction group, and will allow a prompt and steady start of the drift chamber wire stringing as all necessary components became available at LNF. (orig.)

Coaxial wire impedance measurements of BPM buttons for the PEP-II B- factory

International Nuclear Information System (INIS)

Corlett, J.N.

1995-09-01

The coaxial wire impedance measurement uses a conducting rod placed along the beam axis in the vacuum chamber, forming the center conductor in a coaxial line system. Tapers at either end of this section allow for smooth impedance transformation from the 50Ω lines used in common microwave measurement equipment, to the characteristic impedance of the vacuum chamber and center conductor, typically around 200Ω. RF and microwave absorptive material placed in the ends of the vacuum chamber and in the impedance matching tapers minimizes reflections which cause trapped modes within the apparatus, allowing measurements to be made above the traveling-wave cut-off frequency of the vacuum vessel (typically 2.5 - 3.0 GHz for PEP-II). A smooth vessel of the same cross-section as that containing the device under test is used in a reference measurement Resonances within the apparatus are difficult to avoid completely and require careful placing of absorptive material, manufacture of test and reference chambers, and assembly of apparatus

Recommendations for ionization chamber smoke detectors for commercial and industrial fire protection systems (1988)

International Nuclear Information System (INIS)

1989-01-01

Ionization chamber smoke detectors (ICSDs) utilising a radioactive substance as the source of ionization are used to detect the presence of smoke and hence give early warning of a fire. These recommendations are intended to ensure that the use of ICSDs incorporating radium-226 and americium-241 in commercial/industrial fire protection systems does not give rise to any unnecessary radiation exposure

Improvement of the thermo-mechanical position stability of the beam position monitor in the PLS-II

Science.gov (United States)

Ha, Taekyun; Hong, Mansu; Kwon, Hyuckchae; Han, Hongsik; Park, Chongdo

2016-09-01

In the storage ring of the Pohang Light Source-II (PLS-II), we reduced the mechanical displacement of the electron-beam position monitors (e-BPMs) that is caused by heating during e-beam storage. The BPM pickup itself must be kept stable to sub-micrometer precision in order for a stable photon beam to be provided to beamlines because the orbit feedback system is programmed to make the electron beam pass through the center of the BPM. Thermal deformation of the vacuum chambers on which the BPM pickups are mounted is inevitable when the electron beam current is changed by an unintended beam abort. We reduced this deformation by improving the vacuum chamber support and by enhancing the water cooling. We report a thermo-mechanical analysis and displacement measurements for the BPM pickups after improvements.

Wire Chamber

CERN Multimedia

Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Wire chamber

CERN Multimedia

1967-01-01

Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Investigation of droplet nucleation in CCS relevant systems - design and testing of the expansion chamber

Science.gov (United States)

Čenský, Miroslav; Hrubý, Jan; Vinš, Václav; Hykl, Jiří; Šmíd, Bohuslav

2018-06-01

A unique in-house designed experimental apparatus for investigation of nucleation of droplets in CCS relevant systems is being developed by the present team. The apparatus allows simulating various processes relevant to CCS technologies. Gaseous mixtures with CO2 are prepared in a Mixture Preparation Device (MPD) based on accurate adjustment of flow rates of individual components [EPJ Web of Conferences 143, 02140 (2017)]. The mixture then flows into an expansion chamber, where it undergoes a rapid adiabatic expansion. As a consequence of adiabatic cooling, the mixture becomes supersaturated and nucleation and simultaneous growth of droplets occurs. In this study, we describe the design and testing of the expansion part of the experimental setup. The rapid expansion was realized using two valve systems, one for low pressures (up to 0.7 MPa) and the other for high pressures (up to 10 MPa). A challenge for a proper design of the expansion system is avoiding acoustic oscillations. These can occur either in the mode of Helmholtz resonator, where the compressible gas in the chamber acts as a spring and the rapidly moving gas in the valve system as a mass, or in the "flute" mode, where acoustic waves are generated in a long outlet tubing.

The muon chambers take centre stage at CMS

CERN Multimedia

2003-01-01

The CMS muon chambers are now starting to arrive at CERN in significant numbers. All in all, the muon system of the CMS detector will comprise some 1400 of these chambers. Twenty percent of those for the endcaps have already been installed, while the assembly of those for the barrel will start in December.

Assessment of Integrated Information System (IIS) in organization ...

African Journals Online (AJOL)

Assessment of Integrated Information System (IIS) in organization. ... to enable the Information System (IS) managers, as well as top management to understand the ... since organisational and strategic aspects in IIS should also be considered.

Case note: ICTR (Case No. ICTR-99-50-AR50: Prosecutor v. Bizimungu, Mugenzi, Bicamumpaka and Mugiraneza: Decision on Prosecutor’s Interlocutory Appeal Against Trial Chamber II Decision of 6 October 2003 Denying Leave to File Amended Indictment)

NARCIS (Netherlands)

de Meester, K.

2008-01-01

Comment on: - ICTR. (2004, February 12), (Case No. ICTR-99-50-AR50: Prosecutor v. Bizimungu, Mugenzi, Bicamumpaka and Mugiraneza: Decision on Prosecutor’s Interlocutory Appeal Against Trial Chamber II Decision of 6 October 2003 Denying Leave to File Amended Indictment) - Individual Opinion of Judge

LHC II system sensitivity to magnetic fluids

CERN Document Server

Cotae, Vlad

2005-01-01

Experiments have been designed to reveal the influences of ferrofluid treatment and static magnetic field exposure on the photosynthetic system II, where the light harvesting complex (LHC II) controls the ratio chlorophyll a/ chlorophyll b (revealing, indirectly, the photosynthesis rate). Spectrophotometric measurement of chlorophyll content revealed different influences for relatively low ferrofluid concentrations (10-30 mul/l) in comparison to higher concentrations (70-100 mul/l). The overlapped effect of the static magnetic field shaped better the stimulatory ferrofluid action on LHC II system in young poppy plantlets.

Technical realization of a closure concept for a chamber-system in the underground Richard repository in the Czech Republic

International Nuclear Information System (INIS)

Kucerka, Miroslav

2006-01-01

The Phare project CZ 632.02.04 'Realization of closure of a chamber in the Richard repository as input for establishing a safety case' is a follow up implementation phase of the Phare project, CZ 01.14.03 'Solution for closure of a chamber in the Richard repository'. Main objective of both projects is to propose and realize a disposal system in selected chambers of the Richard repository, which will eliminate burden from the past practices in waste management during the first phase of the Richard repository operation (1965 - 1980) and which will improve its overall long term safety. This objective will be assured by realization of the concept of so called 'hydraulic cage', which technical solution was developed by DBE Technology within the Phare project CZ 01.14.03. The solution is described in the previous presentation 'Hydraulic Cage Concept for Waste Chambers and its Technical Implementation for the Underground Richard Repository, Litomerice, Czech Republic'. (author)

Radiation-hard ceramic Resistive Plate Chambers for forward TOF and T0 systems

Energy Technology Data Exchange (ETDEWEB)

Akindinov, A., E-mail: Alexander.Akindinov@cern.ch [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Dreyer, J.; Fan, X.; Kämpfer, B. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Kiselev, S. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Kotte, R.; Garcia, A. Laso [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Malkevich, D. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Naumann, L. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Nedosekin, A.; Plotnikov, V. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Stach, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Sultanov, R.; Voloshin, K. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation)

2017-02-11

Resistive Plate Chambers with ceramic electrodes are the main candidates for a use in precise multi-channel timing systems operating in high-radiation conditions. We report the latest R&D results on these detectors aimed to meet the requirements of the forward T0 counter at the CBM experiment. RPC design, gas mixture, limits on the bulk resistivity of ceramic electrodes, efficiency, time resolution, counting rate capabilities and ageing test results are presented.

Conditioning of vacuum chamber by RF plasma

International Nuclear Information System (INIS)

Elizondo, J.I.; Nascimento, I.C. do

1985-01-01

A new conditioning vaccum chamber system is presented. It consists in hydrogen plasm generation by microwaves with low electronic temperature (Te approx. 5eV) and low ionization degree. The ions and neutral atoms generated in the reaction: e + H 2 -> H+ H+ e, bomb the chamber walls combinig themselves to impurities of surface and generating several compounds: H 2 O, CO, CH 4 , CO 2 etc. The vacuum system operates continuosly and remove these compounds. A microwave system using magnetron valve (f=2,45 GHz, P=800W) was constructed for TBR (Brazilian tokamak). The gas partial pressures were monitored before, during and after conditioning showing the efficiency of the process. (M.C.K.) [pt

The KLOE drift chamber

International Nuclear Information System (INIS)

Ferrari, A.

2002-01-01

The design and construction of the large drift chamber of the KLOE experiment is presented. The track reconstruction is described, together with the calibration method and the monitoring systems. The stability of operation and the performance are studied with samples of e + e - , K S K L and K + K - events

Culture of normal human blood cells in a diffusion chamber system II. Lymphocyte and plasma cell kinetics

International Nuclear Information System (INIS)

Chikkappa, G.; Carsten, A.L.; Chanana, A.D.; Cronkite, E.P.

1979-01-01

Normal human blood leukocytes were cultured in Millipore diffusion chambers implanted into the peritoneal cavities of irradiated mice. The evaluation of survival and proliferation kinetics of cells in lymphyocytic series suggested that the lymphoid cells are formed from transition of small and/or large lymphocytes, and the lymphoblasts from the lymphoid cells. There was also evidence indicating that some of the cells in these two compartments are formed by proliferation. The evaluation of plasmacytic series suggested that the plasma cells are formed from plasmacytoid-lymphocytes by transition, and the latter from the transition of lymphocytes. In addition, relatively a small fraction of cells in these two compartments are formed by proliferation. mature plasma cells do not and immature plasma cells do proliferate. Estimation of magnitude of plasma cells formed in the cultures at day 18 indicated that at least one plasma cell is formed for every 6 normal human blood lymphocytes introduced into the culture

Construction and use of small chambers for boron trifluoride

International Nuclear Information System (INIS)

Caillat, R.; Lallemant, C.; Valladas, G.

1949-01-01

The fabrication of the chambers (the materials used, the fabrication of the parts and their assembly), and their final testing are described in a first part. Then, the preparation of crude boron fluoride, the storing of the crude, the purification of BF 3 by sublimation and condensation, the pumping, drying and filling up of the chambers, their finishing and sealing are described in a second part. The last part describes the use of the chambers for the counting of slow neutrons: amplification system, pulses discrimination and neutrons counting, accuracy. The characteristics of the amplification circuit used with the chamber are described in the appendix. (J.S.)

Resistive Plate Chamber Performance During the CMS Magnet Test Cosmic Challenge

CERN Document Server

Trentadue, R

2008-01-01

The CMS detector at the CERN Large Hadron Collider (LHC) is equipped with a redundant muon system based on Drift Tubes Chambers (barrel region) and Cathode Strip Chamber (endcap region), and Resistive Plate Chamber (RPC). During the summer and fall 2006 a first integrated test of an entire CMS slice was performed at the SX5 experimental surface hall. The RPC chambers were operated with cosmic rays. The results on the RPC performance are reported.

OPAL Central Detector (Including vertex, jet and Z chambers)

CERN Multimedia

OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the different parts of the tracking system. (This piece includes the vertex, jet and Z chambers) In the picture above, the central detector is the piece being removed to the right.

A 2D ion chamber array audit of wedged and asymmetric fields in an inhomogeneous lung phantom

Energy Technology Data Exchange (ETDEWEB)

Lye, Jessica; Dunn, Leon, E-mail: leon.dunn@arpansa.gov.au; Alves, Andrew [Australian Clinical Dosimetry Service, Yallambie, Victoria 3085 (Australia); Kenny, John [Australian Clinical Dosimetry Service, Yallambie, Victoria 3085, Australia and Radiation Oncology Queensland, Toowoomba, Queensland 4350 (Australia); Lehmann, Joerg; Williams, Ivan [Australian Clinical Dosimetry Service, Yallambie, Victoria 3085, Australia and School of Applied Science, RMIT University, Melbourne 3000 (Australia); Kron, Tomas [School of Applied Science, RMIT University, Melbourne 3000, Australia and Peter MacCallum Cancer Centre, Melbourne 3008 (Australia); Cole, Andrew [Australian Clinical Dosimetry Service, Yallambie, Victoria 3085, Australia and Australian Radiation Protection and Nuclear Safety Agency, Yallambie, Victoria 3085 (Australia)

2014-10-15

Purpose: The Australian Clinical Dosimetry Service (ACDS) has implemented a new method of a nonreference condition Level II type dosimetric audit of radiotherapy services to increase measurement accuracy and patient safety within Australia. The aim of this work is to describe the methodology, tolerances, and outcomes from the new audit. Methods: The ACDS Level II audit measures the dose delivered in 2D planes using an ionization chamber based array positioned at multiple depths. Measurements are made in rectilinear homogeneous and inhomogeneous phantoms composed of slabs of solid water and lung. Computer generated computed tomography data sets of the rectilinear phantoms are supplied to the facility prior to audit for planning of a range of cases including reference fields, asymmetric fields, and wedged fields. The audit assesses 3D planning with 6 MV photons with a static (zero degree) gantry. Scoring is performed using local dose differences between the planned and measured dose within 80% of the field width. The overall audit result is determined by the maximum dose difference over all scoring points, cases, and planes. Pass (Optimal Level) is defined as maximum dose difference ≤3.3%, Pass (Action Level) is ≤5.0%, and Fail (Out of Tolerance) is >5.0%. Results: At close of 2013, the ACDS had performed 24 Level II audits. 63% of the audits passed, 33% failed, and the remaining audit was not assessable. Of the 15 audits that passed, 3 were at Pass (Action Level). The high fail rate is largely due to a systemic issue with modeling asymmetric 60° wedges which caused a delivered overdose of 5%–8%. Conclusions: The ACDS has implemented a nonreference condition Level II type audit, based on ion chamber 2D array measurements in an inhomogeneous slab phantom. The powerful diagnostic ability of this audit has allowed the ACDS to rigorously test the treatment planning systems implemented in Australian radiotherapy facilities. Recommendations from audits have led to

A 2D ion chamber array audit of wedged and asymmetric fields in an inhomogeneous lung phantom

International Nuclear Information System (INIS)

Lye, Jessica; Dunn, Leon; Alves, Andrew; Kenny, John; Lehmann, Joerg; Williams, Ivan; Kron, Tomas; Cole, Andrew

2014-01-01

Purpose: The Australian Clinical Dosimetry Service (ACDS) has implemented a new method of a nonreference condition Level II type dosimetric audit of radiotherapy services to increase measurement accuracy and patient safety within Australia. The aim of this work is to describe the methodology, tolerances, and outcomes from the new audit. Methods: The ACDS Level II audit measures the dose delivered in 2D planes using an ionization chamber based array positioned at multiple depths. Measurements are made in rectilinear homogeneous and inhomogeneous phantoms composed of slabs of solid water and lung. Computer generated computed tomography data sets of the rectilinear phantoms are supplied to the facility prior to audit for planning of a range of cases including reference fields, asymmetric fields, and wedged fields. The audit assesses 3D planning with 6 MV photons with a static (zero degree) gantry. Scoring is performed using local dose differences between the planned and measured dose within 80% of the field width. The overall audit result is determined by the maximum dose difference over all scoring points, cases, and planes. Pass (Optimal Level) is defined as maximum dose difference ≤3.3%, Pass (Action Level) is ≤5.0%, and Fail (Out of Tolerance) is >5.0%. Results: At close of 2013, the ACDS had performed 24 Level II audits. 63% of the audits passed, 33% failed, and the remaining audit was not assessable. Of the 15 audits that passed, 3 were at Pass (Action Level). The high fail rate is largely due to a systemic issue with modeling asymmetric 60° wedges which caused a delivered overdose of 5%–8%. Conclusions: The ACDS has implemented a nonreference condition Level II type audit, based on ion chamber 2D array measurements in an inhomogeneous slab phantom. The powerful diagnostic ability of this audit has allowed the ACDS to rigorously test the treatment planning systems implemented in Australian radiotherapy facilities. Recommendations from audits have led to

MAN-IN-SIMULANT TEST (MIST) CHAMBER

Data.gov (United States)

Federal Laboratory Consortium — The MIST chamber uses methyl salicylate (oil of wintergreen) vapor as a simulant for HD agent to conduct system level evaluations of chemical protective ensembles....

Present status of the TJ-II remote participation system

International Nuclear Information System (INIS)

Vega, J.; Sanchez, E.; Lopez, A.; Portas, A.; Ochando, M.; Ascasibar, E.; Mollinedo, A.; Munoz, J.; Sanchez, A.; Ruiz, M.; Barrera, E.; Lopez, S.; Castro, R.; Lopez, D.

2005-01-01

The TJ-II remote participation system (RPS) was designed to extend to Internet the working capabilities provided in the TJ-II local environment, i.e., tracking the TJ-II operation, monitoring/programming data acquisition and control systems, and accessing databases. The TJ-II RPS was based on web and Java technologies because of their open character, security properties and technological maturity. A web server acts as a communication front-end between remote participants and local TJ-II elements. From the server side, web services are provided by means of resources supplied by JSP pages. The client part makes use of web browsers and ad hoc Java applications. The operation requires the use of a distributed authentication and authorization system. This development employs the PAPI System. At present, approximately 1000 digitisation channels can be managed from the TJ-II RPS. Furthermore, processing software based on a 4GL language (LabView) can be downloaded to multiprocessor data acquisition systems. Also, 15 diagnostic control systems, databases and the operation logbook are available from the RPS. The system even allows for the physicist in charge of operation to be in a remote location. Four Spanish universities make use of the TJ-II remote participation system capabilities for joint collaborations: these are the Universidad Politecnica de Madrid (UPM), Universidad Nacional de Educacion a Distancia (UNED), Universidad Complutense de Madrid (UCM) and Universidad Politecnica de Cataluna (UPC)

Special design issues. Ion beam driver-reaction chamber interfaces

International Nuclear Information System (INIS)

Moir, R.W.; Peterson, R.R.; Kessler, G.

1995-01-01

Design issues of the interface between ion beam drivers and the reaction chamber for heavy ion beam and light ion beam inertial fusion drivers are discussed. The interface must provide for radiation protection of final focusing magnets, pumping of evaporated material and non-condensable gas that enter the beam ports, thermal insulation, heat removal, a.o.. Beam ports and focal magnets must be protected by neutronically thick shielding between the beam path and the magnet conductor. The required thickness of the shielding determines the minimum spacing between individual beams in a cluster of beams. The cone angle of this cluster can affect target performance. The beamlines are subjected to evaporated material, debris, and rapidly moving droplets. The reaction chambers used here are HYLIFE-II for indirect, HIBALL-II for direct drive. The light ion beam interface is based on the LIBRA and LIBRA-LiTE studies. In the case of HYLIFE-II, liquid jets must be demonstrated with a thickness of 0.5 m and with an edge that comes to within 10 mm of the beam edges to protect the ports. Design of compact focal arrays with enough shielding to give magnets an adequate lifetime must be achieved. As shielding is added the size of the beam array will grow and the target will drop. For HIBALL neutron shielding of the focal magnets provides an adequate lifetime. Replaceable special INPORT units will have to be developed in the region of the beam ports. For light ions transport issues have led to structures being placed close enough to the target that they experience a higher neutron damage rate and must be replaced once or twice a year, which would require remote maintenance. Light ion concepts could greatly benefit from a self-pinched transport scheme, though the details are unclear and the effect on availability is uncertain. Light and heavy ions have similar problems in keeping the gas in the drivers at a low density. Both will require active means to preserve this low density, while

NEG coating of the non-standard LSS vacuum chambers

CERN Document Server

Costa-Pinto, P

2005-01-01

The vacuum chambers of nearly all the warm magnets of the LHC (MBXW, MQW, MSI, MSD, etc…) will be coated with a Ti-Zr-V thin film by magnetron sputtering. The NEG coating is necessary to provide uniform pumping speed along the chambers and to suppress electron cloud instabilities and dynamic outgassing. The about 300 chambers will be coated using the existing facility, developed for the production of the standard LSS chambers, after minor modifications mainly due to the different cross sections. In order to cope with the present installation schedule, the production planning will allow processing of different families of chambers in parallel by using two or three coating systems simultaneously. After a brief introduction to the Ti-Zr-V characteristics and performances, the coating facility and strategy will be illustrated as well as the possible conflicts due to uncertainties in the planning of the experimental beam pipes and the standard LSS chambers.

Double chamber ion source

International Nuclear Information System (INIS)

Uman, M.F.; Winnard, J.R.; Winters, H.F.

1978-01-01

The ion source is comprised of two discharge chambers one of which is provided with a filament and an aperture leading into the other chamber which in turn has an extraction orifice. A low voltage arc discharge is operated in an inert gas atmosphere in the filament chamber while an arc of higher voltage is operated in the second ionization chamber which contains a vapor which will give the desired dopant ion species. The entire source is immersed in an axial magnetic field parallel to a line connecting the filament, the aperture between the two chambers and the extraction orifice. (author)

Implementing real-time robotic systems using CHIMERA II

Science.gov (United States)

Stewart, David B.; Schmitz, Donald E.; Khosla, Pradeep K.

1990-01-01

A description is given of the CHIMERA II programming environment and operating system, which was developed for implementing real-time robotic systems. Sensor-based robotic systems contain both general- and special-purpose hardware, and thus the development of applications tends to be a time-consuming task. The CHIMERA II environment is designed to reduce the development time by providing a convenient software interface between the hardware and the user. CHIMERA II supports flexible hardware configurations which are based on one or more VME-backplanes. All communication across multiple processors is transparent to the user through an extensive set of interprocessor communication primitives. CHIMERA II also provides a high-performance real-time kernel which supports both deadline and highest-priority-first scheduling. The flexibility of CHIMERA II allows hierarchical models for robot control, such as NASREM, to be implemented with minimal programming time and effort.

Design of automatic control system of temperature in radon chamber controlled by air-condition based on 485 BUS

International Nuclear Information System (INIS)

Man Zaigang; Wang Renbo; Zhang Xiongjie; Zhu Zhifu; Tang Bin

2009-01-01

Radon chamber can be widely used in various radon measurement instruments for calibration, testing and radon environment experiment. According to requisition, radon chamber temperature should be controllable from +10 degree C to +30 degree C, and the temperature control accuracy of the system reaches ±1 degree C. The design of automatic temperature controlled by air-condition based on 485 BUS is introduced. The software and hardware techniques of how the ATMEL89S52 micro controller controls air-condition and communicates with computer are elaborated on. (authors)

Multichannel micromanipulator and chamber system for recording multineuronal activity in alert, non-human primates.

Science.gov (United States)

Gray, Charles M; Goodell, Baldwin; Lear, Alex

2007-07-01

We describe the design and performance of an electromechanical system for conducting multineuron recording experiments in alert non-human primates. The system is based on a simple design, consisting of a microdrive, control electronics, software, and a unique type of recording chamber. The microdrive consists of an aluminum frame, a set of eight linear actuators driven by computer-controlled miniature stepping motors, and two printed circuit boards (PCBs) that provide connectivity to the electrodes and the control electronics. The control circuitry is structured around an Atmel RISC-based microcontroller, which sends commands to as many as eight motor control cards, each capable of controlling eight motors. The microcontroller is programmed in C and uses serial communication to interface with a host computer. The graphical user interface for sending commands is written in C and runs on a conventional personal computer. The recording chamber is low in profile, mounts within a circular craniotomy, and incorporates a removable internal sleeve. A replaceable Sylastic membrane can be stretched across the bottom opening of the sleeve to provide a watertight seal between the cranial cavity and the external environment. This greatly reduces the susceptibility to infection, nearly eliminates the need for routine cleaning, and permits repeated introduction of electrodes into the brain at the same sites while maintaining the watertight seal. The system is reliable, easy to use, and has several advantages over other commercially available systems with similar capabilities.

Overview of the TJ-II remote participation system

International Nuclear Information System (INIS)

Vega, J.; Sanchez, E.; Portas, A.; Pereira, A.; Mollinedo, A.; Munoz, J.A.; Ruiz, M.; Barrera, E.; Lopez, S.; Machon, D.; Castro, R.; Lopez, D.

2006-01-01

The TJ-II remote participation system (RPS) is focused on providing remote access to elements that depend exclusively on characteristics of the TJ-II environment: data acquisition, diagnostics control systems and TJ-II operation tracking. Four key points were taken into account prior to starting the software design: access security, software execution platforms, software maintenance and distribution and delivery of operation events. The first, access security, was addressed by means of a distributed authentication and authorization system, PAPI. Regarding the other points, the development was based on the use of web servers (due to their standard character, flexibility and scalability) and Java technologies (due to their open nature, security properties and technological maturity). Software deployment was prepared to make use of the Java Network Launching Protocol (JNLP). On-line message distribution was planned according to a message oriented middleware. At present, the TJ-II RPS manages over 1000 digitization channels and 20 diagnostic control systems. The TJ-II RPS architecture is flexible, scalable and powerful enough to be applied to distributed environments and, in particular, it could be used in the ITER environment

Overview of the TJ-II remote participation system

Energy Technology Data Exchange (ETDEWEB)

Vega, J. [Asociacion EURATOM/CIEMAT para Fusion, Avda. Complutense, 22, 28040 Madrid (Spain)]. E-mail: jesus.vega@ciemat.es; Sanchez, E. [Asociacion EURATOM/CIEMAT para Fusion, Avda. Complutense, 22, 28040 Madrid (Spain); Portas, A. [Asociacion EURATOM/CIEMAT para Fusion, Avda. Complutense, 22, 28040 Madrid (Spain); Pereira, A. [Asociacion EURATOM/CIEMAT para Fusion, Avda. Complutense, 22, 28040 Madrid (Spain); Mollinedo, A. [Computer Centre, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain); Munoz, J.A. [Computer Centre, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain); Ruiz, M. [Dpto. De Sistemas Electronicos y de Control, UPM, Campus Sur, Ctra. Valencia km 7, 28031 Madrid (Spain); Barrera, E. [Dpto. De Sistemas Electronicos y de Control, UPM, Campus Sur, Ctra. Valencia km 7, 28031 Madrid (Spain); Lopez, S. [Dpto. De Sistemas Electronicos y de Control, UPM, Campus Sur, Ctra. Valencia km 7, 28031 Madrid (Spain); Machon, D. [Dpto. De Sistemas Electronicos y de Control, UPM, Campus Sur, Ctra. Valencia km 7, 28031 Madrid (Spain); Castro, R. [Red.es-RedIRIS, Edificio Bronce, Plaza Manuel Gomez Moreno s/n, 28020 Madrid (Spain); Lopez, D. [Red.es-RedIRIS, Edificio Bronce, Plaza Manuel Gomez Moreno s/n, 28020 Madrid (Spain)

2006-07-15

The TJ-II remote participation system (RPS) is focused on providing remote access to elements that depend exclusively on characteristics of the TJ-II environment: data acquisition, diagnostics control systems and TJ-II operation tracking. Four key points were taken into account prior to starting the software design: access security, software execution platforms, software maintenance and distribution and delivery of operation events. The first, access security, was addressed by means of a distributed authentication and authorization system, PAPI. Regarding the other points, the development was based on the use of web servers (due to their standard character, flexibility and scalability) and Java technologies (due to their open nature, security properties and technological maturity). Software deployment was prepared to make use of the Java Network Launching Protocol (JNLP). On-line message distribution was planned according to a message oriented middleware. At present, the TJ-II RPS manages over 1000 digitization channels and 20 diagnostic control systems. The TJ-II RPS architecture is flexible, scalable and powerful enough to be applied to distributed environments and, in particular, it could be used in the ITER environment.

Readout and trigger electronics for the TPC vertex chamber

International Nuclear Information System (INIS)

Ronan, M.T.; Jared, R.C.; McGathen, T.K.; Eisner, A.M.; Broeder, W.J.; Godfrey, G.L.

1987-10-01

The introduction of the vertex chamber required the addition of new front-end electronics and a new 1024-channel, high-accuracy TDC system. The preamplifier/discriminator should be capable of triggering on the first electrons and the time digitzer should preserve the measurement resolution. For the TDC's, in order to maintain compatibility with the existing TPC readout system, an upgrade of a previous inner drift chamber digitizer system has been chosen. Tests of the accuracy and stability of the original design indicated that the new design specifications would be met. The TPC detector requires a fast pretrigger to turn on its gating grid within 500 ns of the e/sup +/e/sup -/ beam crossing time, to minimize the loss of ionization information. A pretrigger based on the Straw Chamber signals, operating at a rate of about 2 K/sec, will be used for charged particle final states. In addition, in order to reject low mass Two-Photon events at the final trigger level, an accurate transverse momentum cutoff will be made by the Straw Chamber trigger logic. In this paper, we describe the readout and trigger electronics systems which have been built to satisfy the above requirements. 5 refs., 8 figs

Evaluation of the energy dependence of ionization chambers pencil type calibrated beam tomography standards

International Nuclear Information System (INIS)

Fontes, Ladyjane Pereira; Potiens, Maria da Penha A.

2015-01-01

The Instrument Calibration Laboratory of IPEN (LCI - IPEN) performs calibrations of pencil-type ionization chambers (IC) used in measures of dosimetric survey on clinical systems of Computed Tomography (CT). Many users make mistakes when using a calibrated ionization chamber in their CT dosimetry systems. In this work a methodology for determination of factors of correction for quality (Kq) through the calibration curve that is specific for each ionization chamber was established. Furthermore, it was possible to demonstrate the energy dependence on an pencil-type Ionization Chamber(IC) calibrated at the LCI - IPEN. (author)

A shielding chamber for the Rossendorf whole body counter

International Nuclear Information System (INIS)

Beutmann, A.; Ebert, S.; Kaden, M.; Loehnert, D.; Doerfel, H.R.; Schreiber, W.; Helbig, S.

2016-01-01

In connection with the relocation of the incorporation measurement point operated by the VKTA, a new shielding chamber was designed. The development of the new shielding chamber will be shown based on the design study by IDEA System and the inquiries for material availability, procurement of material and assembly technology up to fabrication, assembly and completion of the chamber. The accompanying background measurements through In-situ gamma spectrometry and first experiences with incorporation measurements at the new In-Vivo measurement facility are shown.

A high-efficiency acoustic chamber and the anomalous sample rotation

Science.gov (United States)

Wang, Taylor G.; Allen, J. L.

1992-01-01

A high efficiency acoustic chamber for the levitation and manipulation of liquid or molten samples in a microgravity environment has been developed. The chamber uses two acoustic drivers that are mounted at opposite corners of the chamber; by driving these at the same frequency, with 18-deg phase shifts, an increase in force of a factor of 3-4 is obtainable relative to the force of a single-driver system that is operated at the same power level. This enhancement is due to the increased coupling between the sound driver and the chamber. An anomalous rotation is noted to be associated with the chamber; this is found to be eliminated by a physically as-yet inexplicable empirical solution.

Measurements of anterior chamber depth, white-to-white distance, anterior chamber angle, and pupil diameter using two Scheimpflug imaging devices

Directory of Open Access Journals (Sweden)

Alberto Domínguez-Vicent

2014-08-01

Full Text Available Purpose: To compare the ocular anterior chamber depth, white-to-white distance, anterior chamber angle, and pupil diameter, as measured with two different Scheimpflug imaging devices. Methods: This transversal study included 80 right eyes from 80 subjects aged from 20 to 40 years. Their spherical equivalents ranged from -4.25 to +1.00 diopters (D. Each eye's anterior chamber depth, white-to-white distance, anterior chamber angle, and pupil diameter, were measured for far vision using both the Galilei G4 (double Scheimpflug camera and the Pentacam HR (single Scheimpflug camera systems. Results: Mean anterior chamber depths were calculated as 3.12 ± 0.23 mm and 3.19 ± 0.24 mm when measured with the Galilei G4 and the Pentacam HR, respectively. The mean white-to-white distance measured was 11.84 ± 0.31 mm and 11.90 ± 0.43 mm when measured with the Galilei G4 and the Pentacam HR, respectively. Mean pupil diameters were measured as 3.22 ± 0.58 mm and 3.22 ± 0.52 mm when measured with the Galilei G4 and the Pentacam HR, respectively. Finally, the mean anterior chamber angle was 34.30 ± 2.86 degrees when it was measured with the Galilei G4, and 39.26 ± 2.85 degrees when measured with the Pentacam HR. A comparative analysis revealed that the Galilei G4 yielded a significantly lower (P0.05 for both devices were obtained for the white-to-white distance measurements. Conclusion: The Galilei G4 and Pentacam HR Scheimpflug systems cannot be used interchangeably because they produce significant measurement differences.

The Mark II detector for the SLC

International Nuclear Information System (INIS)

Abrams, G.; Baden, A.R.; Boyer, J.; Butler, F.; Drell, P.S.; Fay, J.; Gidal, G.; Goldhaber, G.; Haggerty, J.; Harr, R.; Hearty, C.; Herrup, D.; Holmgren, S.O.; Jaffre, M.; Juricic, I.; Kadyk, J.A.; Kral, J.F.; Levi, M.E.; Lynch, G.R.; Richman, J.D.; Rouse, F.R.; Schaad, M.W.; Schmidke, W.B.; Schumm, B.A.; Trilling, G.H.; Wood, D.R.; Akerlof, C.; Bonvicini, G.; Chapman, J.; Chmeissani, M.; Frey, R.; Gero, E.; Hong, S.J.; Koska, W.; Nitz, D.; Petradza, M.; Thun, R.; Tschirhart, R.; Veltman, H.; Alexander, J.P.; Ballam, J.; Barklow, T.; Bartelt, J.; De Boer, W.; Boyarski, A.; Braune, K.; Bulos, F.; Burke, D.L.; Cords, D.; Coupal, D.P.; Destaebler, H.C.; Dorfan, J.M.; Feldman, G.J.; Fernandes, D.; Field, R.C.; Fordham, C.; Fujino, D.; Gan, K.K.; Glanzman, T.; Grosse-Wiesmann, P.; Hanson, G.; Hayes, K.; Himel, T.; Hutchinson, D.; Innes, W.R.; Jacobsen, R.G.; Jaros, J.A.; Jung, C.K.; Karlen, D.; Klein, S.R.; Koetke, D.; Komamiya, M.; Kowalski, L.A.; Kozanecki, W.; Lankford, A.J.; Larsen, R.R.; Lueth, V.; Mattison, T.; Moffeit, K.C.; Mueller, L.; Munger, C.T.; Nash, J.; Ong, R.A.; O'Shaughnessy, K.F.; Perl, J.; Perl, M.L.; Perrier, F.; Petersen, A.; Pitthan, R.; Riles, K.; Swartz, M.; Taylor, R.E.; Van Kooten, R.; Voruganti, P.; Weigend, A.; Woods, M.; Wormser, G.; Wright, R.; Alvarez, M.; Calvino, F.; Fernandez, E.; Ford, W.T.; Hinshaw, D.A.; Rankin, P.; Smith, J.G.; Wagner, S.R.; Weber, P.; White, S.L.; Averill, D.; Blockus, D.; Brabson, B.; Brom, J.M.; Murray, W.N.; Ogren, H.; Rust, D.R.; Snyder, A.; Yurko, M.; Barish, B.C.; Hawkes, C.M.; Hoenk, M.; Kuhlen, M.; Li, Z.; McKenna, J.A.; Milliken, B.D.; Nelson, M.E.; Peck, C.; Porter, F.C.; Soderstrom, E.; Stroynowski, R.; Weinstein, A.J.; Weir, A.J.; Wicklund, E.; Wolf, R.C.; Wu, D.Y.; Barnett, B.A.; Boswell, C.; Dauncey, P.; Drewer, D.C.; Harral, B.; Hylen, J.; Matthews, J.A.J.; Stoker, D.P.; Vejcik, S.; Breakstone, A.; Cence, R.J.; Gong, X.; Harris, F.A.; Koide, A.; Parker, S.I.; Green, A.; Lawrence Berkeley Lab., CA; California Univ., Berkeley

1989-01-01

The Mark II detector has been upgraded in preparation for its role as the first detector to take data at the Stanford Linear Collider. The new detector components include the central drift chamber, the time-of-flight system, the coil, the endcap electromagnetic calorimeters and the beam energy and luminosity measuring devices. There have also been improvements in detector hermeticity. All of the major components were installed for a test run at the PEP storage ring (√s=29 GeV) in 1985. This paper describes the upgraded detector, including its trigger and data acquisition systems, and gives performance figures for its components. Future improvements are also discussed. (orig.)

Closed chamber globe stabilization and needle capsulorhexis using irrigation hand piece of bimanual irrigation and aspiration system

Directory of Open Access Journals (Sweden)

Rai Harminder K

2005-08-01

Full Text Available Abstract Background The prerequisites for a good capsulorhexis include a deep, well maintained anterior chamber, globe stabilization and globe manipulation. This helps to achieve a capsulorhexis of optimal size, shape and obtain the best possible position for a red glow under retroillumination. We report the use of irrigation handpiece of bimanual irrigation aspiration system to stabilize the globe, maintain a deep anterior chamber and manipulate the globe to a position of optimal red reflex during needle capsulorhexis in phacoemulsification. Methods Two side ports are made with 20 G MVR 'V' lance knife (Alcon, USA. The irrigation handpiece with irrigation on is introduced into the anterior chamber through one side port and the 26-G cystitome (made from 26-G needle is introduced through the other. The capsolurhexis is completed with the needle. Results Needle capsulorhexis with this technique was used in 30 cases of uncomplicated immature senile cataracts. 10 cases were done under peribulbar anaesthesia and 20 under topical anaesthesia. A complete capsulorhexis was achieved in all cases. Conclusion The irrigating handpiece maintains deep anterior chamber, stabilizes the globe, facilitates pupillary dilatation, and helps in maintaining the eye in the position with optimal red reflex during needle capsulorhexis. This technique is a safe and effective way to perform needle capsulorhexis.

Gridded ionization chamber

International Nuclear Information System (INIS)

Houston, J.M.

1977-01-01

An improved ionization chamber type x-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is disposed adjacent the anode and is maintained at a voltsge intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting toward the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

Hot gas path component cooling system having a particle collection chamber

Science.gov (United States)

Miranda, Carlos Miguel; Lacy, Benjamin Paul

2018-02-20

A cooling system for a hot gas path component includes a substrate having an outer surface and an inner surface. The inner surface defines at least one interior space. A passage is formed in the substrate between the outer surface and the inner surface. An access passage is formed in the substrate and extends from the outer surface to the inner space. The access passage is formed at a first acute angle to the passage and includes a particle collection chamber. The access passage is configured to channel a cooling fluid to the passage. Furthermore, the passage is configured to channel the cooling fluid therethrough to cool the substrate.

Measurements and Simulations of Ionization Chamber Signals in Mixed Radiation Fields for the LHC BLM System

CERN Document Server

Dehning, B; Ferioli, G; Holzer, EB; Stockner, M

2006-01-01

The LHC beam loss monitoring (BLM) system must prevent the super conducting magnets from quenching and protect the machine components from damage. The main monitor type is an ionization chamber. About 4000 of them will be installed around the ring. The lost beam particles initiate hadronic showers through the magnets, which are measured by the monitors installed outside of the cryostat around each quadrupole magnet. They probe the far transverse tail of the hadronic shower. The specification for the BLM system includes a factor of two absolute precision on the prediction of the quench levels. To reach this accuracy a number of simulations are being combined to calibrate the monitor signals. To validate the monitor calibration the simulations are compared with test measurements. This paper will focus on the simulated prediction of the development of the hadronic shower tails and the signal response of ionization chambers to various particle types and energies. Test measurements have been performed at CERN and ...

Tracking simulation and wire chamber requirements for the SSC

International Nuclear Information System (INIS)

Hanson, G.G.; Niczyporuk, B.B.; Palounek, A.P.T.

1988-11-01

Limitations placed on wire chambers by radiation damage and rate requirements in the SSC environment are reviewed. Possible conceptual designs for wire chamber tracking systems which meet these requirements are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 16 refs., 16 figs., 2 tabs

Neuroprotective Effects and Mechanisms of Curcumin–Cu(II and –Zn(II Complexes Systems and Their Pharmacological Implications

Directory of Open Access Journals (Sweden)

Fa-Shun Yan

2017-12-01

Full Text Available Alzheimer’s disease (AD is the main form of dementia and has a steadily increasing prevalence. As both oxidative stress and metal homeostasis are involved in the pathogenesis of AD, it would be interesting to develop a dual function agent, targeting the two factors. Curcumin, a natural compound isolated from the rhizome of Curcuma longa, is an antioxidant and can also chelate metal ions. Whether the complexes of curcumin with metal ions possess neuroprotective effects has not been evaluated. Therefore, the present study was designed to investigate the protective effects of the complexes of curcumin with Cu(II or Zn(II on hydrogen peroxide (H2O2-induced injury and the underlying molecular mechanisms. The use of rat pheochromocytoma (PC12 cells, a widely used neuronal cell model system, was adopted. It was revealed that curcumin–Cu(II complexes systems possessed enhanced O2·–-scavenging activities compared to unchelated curcumin. In comparison with unchelated curcumin, the protective effects of curcumin–Cu(II complexes systems were stronger than curcumin–Zn(II system. Curcumin–Cu(II or –Zn(II complexes systems significantly enhanced the superoxide dismutase, catalase, and glutathione peroxidase activities and attenuated the increase of malondialdehyde levels and caspase-3 and caspase-9 activities, in a dose-dependent manner. The curcumin–Cu(II complex system with a 2:1 ratio exhibited the most significant effect. Further mechanistic study demonstrated that curcumin–Cu(II or –Zn(II complexes systems inhibited cell apoptosis via downregulating the nuclear factor κB (NF-κB pathway and upregulating Bcl-2/Bax pathway. In summary, the present study found that curcumin–Cu(II or –Zn(II complexes systems, especially the former, possess significant neuroprotective effects, which indicates the potential advantage of curcumin as a promising agent against AD and deserves further study.

Chamber service module (CSM1) for MDT

CERN Document Server

Binchi, P

2002-01-01

CSM-1 is the second and latest version of the high speed electronic unit whose primary task is to multiplex serial data from up to 18 ASD /TDC cards located at the ends of the Monitored Drift Tubes. Each CSM will capture data from all 24 channel TDC (AMT-2 units) of a given chamber and transfer it along a single optic fiber to the MROD, the event builder and readout driver. The core of the board is a Xilinx VirtexII FPGA which will use JTAG protocol (IEEE Std. 1149.1) for logic configuration parameter loading.

Techniques developed for the ATLAS Thin Gap Chambers mass production in Japan

CERN Document Server

Tanaka, S; Ishii, K; Iwasaki, H; Arataki, Y; Bando, T; Homma, Y; Ishino, M; Kondo, T; Kobayashi, T; Kurashige, H; Mikenberg, G; Miyazaki, Y; Nakagawa, Y; Nanjo, H; Ikeno, M; Nozaki, M; Ochi, A; Sasaki, O; Shoa, M; Sugimoto, T; Takeda, H; Takeshita, T; Yokoyama, C

2004-01-01

The Thin Gap Chambers (TGCs) are used for the muon trigger system in the end-cap regions of the ATLAS detector. The TGC mass production phase at High Energy Accelerator Research Organization (KEK) started in January 2001. As the anode-cathode distance is small, 1.4 mm, chamber flatness is essential to achieve a uniform gas gain over the chamber. In order to perform a stable production with high quality we developed a chamber closing system. When we glue two half-chambers together, we sandwich them between a granite table and an aluminum honeycomb panel to keep the chamber flat from both sides. By using silk screens, we control the quantity of epoxy adhesive that affects the chamber thickness. Due to these developments, we can achieve the flatness of less than 100 µm. Uniformity of detection efficiency of the TGC is measured with a cosmic-ray test bench at Kobe University. So far we have tested 300 TGCs. Position dependence of the efficiency is measured with a granularity of 5mm-by-5mm. The average efficiency...

Impedance of the PEP-II DIP screen

Energy Technology Data Exchange (ETDEWEB)

Ng, C -K [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Weiland, T

1996-08-01

The vacuum chamber of a storage ring normally consists of periodically spaced pumping slots. The longitudinal impedance of slots are analyzed in this paper. It is found that although the broad-band impedance is tolerable, the narrow-band impedance, as a consequence of the periodicity of the slots, may exceed the stability limit given by natural damping with no feedback system on. Based on this analysis, the PEP-II distributed-ion-pump (DIP) screen uses long grooves with hidden holes cut halfway to reduce both the broad-band and narrow-band impedances. (author)

Impedance of the PEP-II DIP screen

International Nuclear Information System (INIS)

Ng, C.K.; Weiland, T.

1995-09-01

The vacuum chamber of a storage ring normally consists of periodically spaced pumping slots. The longitudinal impedance of slots are analyzed in this paper. It is found that although the broad-band impedance is tolerable, the narrow-band impedance, as a consequence of the periodicity of the slots, may exceed the stability limit given by natural damping with no feedback system on. Based on this analysis, the PEP-II distributed-ion-pump (DIP) screen uses long grooves with hidden holes cut halfway to reduce both the broad-band and narrow-band impedances

Limited streamer chamber testing and quality evaluation in ASTRA

International Nuclear Information System (INIS)

Anzivino, G.; Bianco, S.; Casaccia, R.

1991-01-01

Limited streamer chambers are extensively used for high-energy and nuclear physics experiments in accelerator and underground laboratories. The tracking system of LVD, an underground experiment to study muons and nutrino astronomy, will use roughly 15000 limited streamer chambers and 100000 external pickup strips with digital readout electronics. In the article the different aspects of chamber operation that serve to establish a testing procedure and to define acceptance criteria for selecting reliable and long-life devices, are discussed. The procedures and the results obtained from a long-term test to evaluate streamer chamber quality, based upon a sample of 2900 items, are described. The selection tests and the long-term observations have been performed in the ASTRA laboratory, established at the Laboratori Nazionali di Frascati to carry out quality control procedures for streamer chambers on a large scale and in a controlled environment

Aerospace Systems Monitor, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Proposal Title: Aerospace Systems Monitor PHASE 1 Technical Abstract: This Phase II STTR project will continue development and commercialization of the Aerospace...

PEP-II Alignment

CERN Document Server

Gaydosh, M

2003-01-01

The PEP-II Asymmetric B-factory consists of two independent storage rings, one located atop the other in the 2200m-circumference PEP tunnel. The high-energy ring, which stores a 9-GeV electron beam, is an upgrade of the existing PEP collider. It re-utilizes all of the PEP magnets and incorporates a state-of-the-art copper vacuum chamber and a new RF system capable of supporting a one-amp stored beam. The low-energy ring, which stores 3.1-GeV positrons, is new construction. Injection is achieved by extracting electrons and positrons at collision energies from the SLC and transporting them each in a dedicated bypass line. The low-emittance SLC beams will be used for the injection process.

Modernization of NASA's Johnson Space Center Chamber: A Liquid Nitrogen System to Support Cryogenic Vacuum Optical Testing of the James Webb Space Telescope (JWST)

Science.gov (United States)

Garcia, Sammy; Homan, Jonathan; Montz, Michael

2016-01-01

NASA is the mission lead for the James Webb Space Telescope (JWST), the next of the “Great Observatories”, scheduled for launch in 2018. It is directly responsible for the integration and test (I&T) program that will culminate in an end-to-end cryo vacuum optical test of the flight telescope and instrument module in Chamber A at NASA Johnson Space Center. Historic Chamber A is the largest thermal vacuum chamber at Johnson Space Center and one of the largest space simulation chambers in the world. Chamber A has undergone a major modernization effort to support the deep cryogenic, vacuum and cleanliness requirements for testing the JWST. This paper describes the steps performed in efforts to convert the existing the 60’s era Liquid Nitrogen System from a forced flow (pumped) process to a natural circulation (thermo-siphon) process. In addition, the paper will describe the dramatic conservation of liquid nitrogen to support the long duration thermal vacuum testing. Lastly, describe the simplistic and effective control system which results in zero to minimal human inputs during steady state conditions.

Recent Advances on OTA Testing for 5G Antenna Systems in Multi-probe Anechoic Chamber Setups

DEFF Research Database (Denmark)

Fan, Wei; Pedersen, Gert F.; Kyösti, Pekka

2018-01-01

Over-the-air (OTA) testing is seen as an essential method for evaluating 5G antenna systems, since conventional cable testing are no longer applicable. In the paper, we discussed the similarities and discrepancies of OTA testing in the multiprobe anechoic chamber (MPAC) setups for 4G user equipment...

Design and construction of automatic operating system of double chamber plasma nitriding device PLC based

International Nuclear Information System (INIS)

Saminto; Slamet Santosa; Eko Priyono

2012-01-01

The automatic operating system of double chamber plasma nitriding device has been done. The system is used for operating double chamber plasma nitriding automatically as according to the standard operating procedure by pressing push button on the human machine interface (HMI). The system consists of hardware and software. The hardware was constructed using main components T100MD1616+ PLC module and supported by temperature signal conditioner module, Wheatstone bridge module, isolated amplifier module and EMS 30A H Bridge motor driver module. A software program that is planted on T100MD1616+ PLC using ladder diagrams and Tbasic program. Test system functions performed by inserting a set values of temperature and pressure by pressing the button on the human machine interface (HMI). The test results show that the temperature control with a set of values 100 °C obtained stable coverage of 98 °C to 102 °C, (Δ ± 2 °C) with a 2% tolerance and the output voltage of the DAC is 2.436 volts to 2.913 volts. The pressure control with a set of values 2.169 x 10 -1 mbar obtained stable coverage of 1.995 x 10 -1 mbar to 2.205 x 10 -1 mbar, (Δ ± 0.105 x 10 -1 mbar) with a 5% tol. (author)

SCORPION II persistent surveillance system update

Science.gov (United States)

Coster, Michael; Chambers, Jon

2010-04-01

This paper updates the improvements and benefits demonstrated in the next generation Northrop Grumman SCORPION II family of persistent surveillance and target recognition systems produced by the Xetron Campus in Cincinnati, Ohio. SCORPION II reduces the size, weight, and cost of all SCORPION components in a flexible, field programmable system that is easier to conceal and enables integration of over fifty different Unattended Ground Sensor (UGS) and camera types from a variety of manufacturers, with a modular approach to supporting multiple Line of Sight (LOS) and Beyond Line of Sight (BLOS) communications interfaces. Since 1998 Northrop Grumman has been integrating best in class sensors with its proven universal modular Gateway to provide encrypted data exfiltration to Common Operational Picture (COP) systems and remote sensor command and control. In addition to feeding COP systems, SCORPION and SCORPION II data can be directly processed using a common sensor status graphical user interface (GUI) that allows for viewing and analysis of images and sensor data from up to seven hundred SCORPION system gateways on single or multiple displays. This GUI enables a large amount of sensor data and imagery to be used for actionable intelligence as well as remote sensor command and control by a minimum number of analysts.

LCLS-II CRYOMODULE TRANSPORT SYSTEM TESTING

Energy Technology Data Exchange (ETDEWEB)

Huque, Naeem [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Daly, Edward F. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); McGee, Michael W. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2018-04-01

The Cryomodules (CM) for the Linear Coherent Light Source II (LCLS-II) will be shipped to SLAC (Menlo Park, California) from JLab (Newport News, Virginia) and FNAL (Batavia, Illinois). A transportation system has been designed and built to safely transport the CMs over the road. It uses an array of helical isolator springs to attenuate shocks on the CM to below 1.5g in all directions. The system rides on trailers equipped with Air-Ride suspension, which attenuates vibration loads. The prototype LCLS-II CM (pCM) was driven 750 miles to test the transport system; shock loggers recorded the shock attenuation on the pCM and vacuum gauges were used to detect any compromises in beamline vacuum. Alignment measurements were taken before and after the trip to check whether cavity positions had shifted beyond the ± 0.2mm spec. Passband frequencies and cavity gradients were measured at 2K at the Cryomodule Test Facility (CMTF) at JLab to identify any degradation of CM performance after transportation. The transport system was found to have safely carried the CM and is cleared to begin shipments from JLab and FNAL to SLAC.

Removal of Pb(II), Cu(II) and Cd(II) from aqueous solution by some fungi and natural adsorbents in single and multiple metal systems

International Nuclear Information System (INIS)

Shoaib, A.; Badar, T.; Aslam, N.

2011-01-01

Six fungal and 10 natural biosorbents were analyzed for their Cu(II), Cd(II) and Pb(II) uptake capacity from single, binary and ternary metal ion system. Preliminary screening biosorption of assays revealed 2 fungi (Aspergillus niger and Cunninghamella echinulata) and three natural [Cicer arietinum husk, Moringa oleifera flower and soil (clay)] adsorbents hold considerable high adsorption efficiency and capacity for 3 meta l ions amongst the adsorbents. Further biosorption trials with five elected adsorbents showed a considerable reduction in metal uptake capability of adsorbents in binary- and ternary systems as compared to singly metal system. Cd(II) manifested the highest inhibitory effect on the biosorption of other metal ions, followed by Pb(II) and Cu(II). On account of metal preference, the selectivity order for metal ion towards the studied biomass matrices was Pb(II) (40-90%) > Cd(II) (2-53%) > Cu(II) (2-30%). (author)

Improvements in ionization chambers

International Nuclear Information System (INIS)

Whetten, N.R.; Zubal, C.

1980-01-01

A method of reducing mechanical vibrations transmitted to the parallel plate electrodes of ionization chamber x-ray detectors, commonly used in computerized x-ray axial tomography systems, is described. The metal plate cathodes and anodes are mounted in the ionizable gas on dielectric sheet insulators consisting of a composite of silicone resin and glass fibres. (UK)

Method for sequentially processing a multi-level interconnect circuit in a vacuum chamber

Science.gov (United States)

Routh, D. E.; Sharma, G. C. (Inventor)

1984-01-01

An apparatus is disclosed which includes a vacuum system having a vacuum chamber in which wafers are processed on rotating turntables. The vacuum chamber is provided with an RF sputtering system and a dc magnetron sputtering system. A gas inlet introduces various gases to the vacuum chamber and creates various gas plasma during the sputtering steps. The rotating turntables insure that the respective wafers are present under the sputtering guns for an average amount of time such that consistency in sputtering and deposition is achieved. By continuous and sequential processing of the wafers in a common vacuum chamber without removal, the adverse affects of exposure to atmospheric conditions are eliminated providing higher quality circuit contacts and functional device.

Unstable systems and repeated measurements. II

International Nuclear Information System (INIS)

Exner, P.

1977-01-01

Two examples are treated. In the first, the chamber structure is only assumed to be periodic and P(t) is an exponential. In the second example no specific assumption is made about the primary decay law and the measuring device is structured as an idealized spark chamber. This example contains the results by Beskow and Nilsson as a special case. (author)

Portable Automation of Static Chamber Sample Collection for Quantifying Soil Gas Flux

Energy Technology Data Exchange (ETDEWEB)

Davis, Morgan P.; Groh, Tyler A.; Parkin, Timothy B.; Williams, Ryan J.; Isenhart, Thomas M.; Hofmockel, Kirsten S.

2018-01-01

Quantification of soil gas flux using the static chamber method is labor intensive. The number of chambers that can be sampled is limited by the spacing between chambers and the availability of trained research technicians. An automated system for collecting gas samples from chambers in the field would eliminate the need for personnel to return to the chamber during a flux measurement period and would allow a single technician to sample multiple chambers simultaneously. This study describes Chamber Automated Sampling Equipment (FluxCASE) to collect and store chamber headspace gas samples at assigned time points for the measurement of soil gas flux. The FluxCASE design and operation is described, and the accuracy and precision of the FluxCASE system is evaluated. In laboratory measurements of nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) concentrations of a standardized gas mixture, coefficients of variation associated with automated and manual sample collection were comparable, indicating no loss of precision. In the field, soil gas fluxes measured from FluxCASEs were in agreement with manual sampling for both N2O and CO2. Slopes of regression equations were 1.01 for CO2 and 0.97 for N2O. The 95% confidence limits of the slopes of the regression lines included the value of one, indicating no bias. Additionally, an expense analysis found a cost recovery ranging from 0.6 to 2.2 yr. Implementing the FluxCASE system is an alternative to improve the efficiency of the static chamber method for measuring soil gas flux while maintaining the accuracy and precision of manual sampling.

He leak testing of Indus-2 dipole vacuum chambers

International Nuclear Information System (INIS)

Sindal, B.K.; Bhavsar, S.T.; Shukla, S.K.

2003-01-01

Full text: Centre for Advanced Technology is developing its second synchrotron radiation source INDUS-2 which is a 2.5 GeV electron storage ring. Dipole vacuum chambers are the vital components of Indus-2 vacuum system. Each of these chambers is approx. 3.6 m long and 0.67 m wide with 24 nos. of ports of various sizes. The dipole chambers were made by machining two halves and they are then lip welded together. The dipole chamber has approx. 14 m of total weld length and it was leak tested for leak tightness of the order of 10 -10 mbar 1/s. Helium mass spectrometer leak detector (HMSLD) was utilized for the leak testing. Subsequently the leaks of various orders in welding joints were repaired and leak tightness achieved. This paper describes the experiences during leak testing of 20 nos. of aluminum dipole chambers for INDUS-2

Investigation of droplet nucleation in CCS relevant systems – design and testing of the expansion chamber

Directory of Open Access Journals (Sweden)

Čenský Miroslav

2018-01-01

Full Text Available A unique in-house designed experimental apparatus for investigation of nucleation of droplets in CCS relevant systems is being developed by the present team. The apparatus allows simulating various processes relevant to CCS technologies. Gaseous mixtures with CO2 are prepared in a Mixture Preparation Device (MPD based on accurate adjustment of flow rates of individual components [EPJ Web of Conferences 143, 02140 (2017]. The mixture then flows into an expansion chamber, where it undergoes a rapid adiabatic expansion. As a consequence of adiabatic cooling, the mixture becomes supersaturated and nucleation and simultaneous growth of droplets occurs. In this study, we describe the design and testing of the expansion part of the experimental setup. The rapid expansion was realized using two valve systems, one for low pressures (up to 0.7 MPa and the other for high pressures (up to 10 MPa. A challenge for a proper design of the expansion system is avoiding acoustic oscillations. These can occur either in the mode of Helmholtz resonator, where the compressible gas in the chamber acts as a spring and the rapidly moving gas in the valve system as a mass, or in the “flute” mode, where acoustic waves are generated in a long outlet tubing.

Dorsal skinfold chamber models in mice

Directory of Open Access Journals (Sweden)

Schreiter, Jeannine

2017-07-01

Full Text Available Background/purpose: The use of dorsal skinfold chamber models has substantially improved the understanding of micro-vascularisation in pathophysiology over the last eight decades. It allows pathophysiological studies of vascularisation over a continuous period of time. The dorsal skinfold chamber is an attractive technique for monitoring the vascularisation of autologous or allogenic transplants, wound healing, tumorigenesis and compatibility of biomaterial implants. To further reduce the animals’ discomfort while carrying the dorsal skinfold chamber, we developed a smaller chamber (the Leipzig Dorsal Skinfold Chamber and summarized the commercial available chamber models. In addition we compared our model to the common chamber. Methods: The Leipzig Dorsal Skinfold Chamber was applied to female mice with a mean weight of 22 g. Angiogenesis within the dorsal skinfold chamber was evaluated after injection of fluorescein isothiocyanate dextran with an Axio Scope microscope. The mean vessel density within the dorsal skinfold chamber was assessed over a period of 21 days at five different time points. The gained data were compared to previous results using a bigger and heavier dorsal skinfold model in mice. A PubMed and a patent search were performed and all papers related to “dorsal skinfold chamber” from 1 of January 2006 to 31 of December 2015 were evaluated regarding the dorsal skinfold chamber models and their technical improvements. The main models are described and compared to our titanium Leipzig Dorsal Skinfold Chamber model.Results: The Leipzig Dorsal Skinfold Chamber fulfils all requirements of continuous models known from previous chamber models while reducing irritation to the mice. Five different chamber models have been identified showing substantial regional diversity. The newly elaborated titanium dorsal skinfold chamber may replace the pre-existing titanium chamber model used in Germany so far, as it is smaller and lighter

Drift Chambers Simulations in BM@N Experiment

Directory of Open Access Journals (Sweden)

Fedorišin Ján

2016-01-01

Full Text Available Drift chambers constitute an important part of the tracking system of the BM@N experiment designed to study the production of baryonic matter at the Nuclotron energies. GEANT programming package is employed to investigate the drift chamber response to particles produced in relativistic nuclear collisions of C+C nuclei, which are simulated by the UrQMD and LAQGSM Monte Carlo generators. These simulations are combined with the first BM@N experimental data to estimate particle track coordinates and their errors.

Numerical analysis on the effect of swirl ratios on swirl chamber combustion system of DI diesel engines

International Nuclear Information System (INIS)

Wei, Shengli; Wang, Feihu; Leng, Xianyin; Liu, Xin; Ji, Kunpeng

2013-01-01

Highlights: • A new swirl chamber combustion system of DI diesel engines is proposed. • The appropriate vortex motion can reduce the wall concentration of mixture. • It has best emissions at swirl ratio of 0.8. • Before spray, the turbulent kinetic energy is primarily controlled by the squish. • After spray, the combustion swirl and reverse squish have a great impact on TKE. - Abstract: In order to improve the spray spatial distribution and promote the mixture quality, enhancing airflow movement in a combustion chamber, a new swirl chamber combustion system in direct injection (DI) diesel engines is proposed. The mixture formation and combustion progress in the cylinder are simulated and investigated at several different swirl ratios by using the AVL-FIRE code. The results show that in view of the fuel/air equivalence ratio distribution, the uniformity of mixture with swirl ratio of 0.2 is better. Before spray injection, the turbulent kinetic energy distribution is primarily controlled by the squish. After spray, the combustion swirl and reverse squish swirl have an effect on temperature distribution and turbulent kinetic energy (TKE) in the cylinder. The NO mass fraction is the lowest at swirl ratio of 0.8 and the highest at swirl ratio of 2.7, while Soot mass fraction is the lowest at swirl ratio of 0.2 and the highest at swirl ratio of 3.2. The appropriate swirl is benefit to improve combustion. To sum up, the emissions at swirl ratio of 0.8 has a better performance in the new combustion system

Manufacture of the straight section chambers for the SPring-8 storage ring

International Nuclear Information System (INIS)

Watanabe, K.; Saeki, H.; Sakaue, H.; Ohkuma, H.; Be, S.H.; Oishi, M.; Tuchiya, M.; Nishidono, T.

1995-01-01

To carry out the performance test of the vacuum system, we manufactured three different straight section chambers prior to the manufacture of the 48 cell full scale vacuum systems. One of three straight section chambers contains only downstream end absorber, while the other two contain a downstream end absorber, upstream end bellows and a photon beam extraction duct. In this paper, the manufacture of these chambers and their assemblies are described in detail. (author). 1 ref., 3 figs., 3 tabs

Review of wire chamber aging

International Nuclear Information System (INIS)

Va'Vra, J.

1986-02-01

This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs

Performance of the Soudan II honeycomb drift chambers

International Nuclear Information System (INIS)

Ambats, I.; Ayres, D.; Barrett, W.

1987-01-01

The Soudan II nucleon decay project is in the process of building 260 identical 5-ton fine grained calorimeter modules for the study of nucleon decay and cosmic ray physics in the Soudan Iron Mine in Minnesota. Several of these modules have been studied on a cosmic ray test stand on the surface at Argonne National Lab. Several have been installed on location in the mine, 700 m under the surface (2200 mwe overburden). In addition, many studies of trigger efficiency, pattern recognition and background rejection have been done using Monte Carlo techniques

Mycocardial perfusion scintigraphy using a new technique, the mesh chamber

International Nuclear Information System (INIS)

Osborne, L.S.; Holman, B.L.

1984-06-01

The 10cm x 10cm chamber has been used in conjunction with a new reconstruction algorithm. Ongoing investigations are testing system performance, including three-dimensional resolution and contrast ratio for various objects. The chambers have had some reliability problems. 30 references, 7 figures

Standardization Of 166mHo Using Merlin Gerin Ionization Chamber System

International Nuclear Information System (INIS)

Nazaroh; Chandra; Hermawan; Juita Erni

2000-01-01

Standardization of 166m Ho using Merlin Gerin ionization chamber system has been carried out. Solution of 166m Ho was obtained from ETL-Japan. Activity measurement of 166m Ho was done before and after preparation. The result of activity measurement by P3KRBiN before preparation was (134.47±0.4) kBq/g, and after preparation was (131.98±1.85) kBq/g, at reference time, 1 March 1999. The ETL's result was (130.4±0.4) kBq/g, at the same reference time. The difference between P3KRBiN's (without uncertainty) and ETL's measurement result was 1.2% and if the uncertainty was included, both measurements was agreed

Design and construction of an inexpensive homemade plant growth chamber.

Science.gov (United States)

Katagiri, Fumiaki; Canelon-Suarez, Dario; Griffin, Kelsey; Petersen, John; Meyer, Rachel K; Siegle, Megan; Mase, Keisuke

2015-01-01

Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W) x 1.8 m (D) x 2 m (H), providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140-250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant growth chamber

Design and construction of an inexpensive homemade plant growth chamber.

Directory of Open Access Journals (Sweden)

Fumiaki Katagiri

Full Text Available Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W x 1.8 m (D x 2 m (H, providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140-250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant

New fossil remains of Homo naledi from the Lesedi Chamber, South Africa

Science.gov (United States)

Hawks, John; Elliott, Marina; Schmid, Peter; Churchill, Steven E; de Ruiter, Darryl J; Roberts, Eric M; Hilbert-Wolf, Hannah; Garvin, Heather M; Williams, Scott A; Delezene, Lucas K; Feuerriegel, Elen M; Randolph-Quinney, Patrick; Kivell, Tracy L; Laird, Myra F; Tawane, Gaokgatlhe; DeSilva, Jeremy M; Bailey, Shara E; Brophy, Juliet K; Meyer, Marc R; Skinner, Matthew M; Tocheri, Matthew W; VanSickle, Caroline; Walker, Christopher S; Campbell, Timothy L; Kuhn, Brian; Kruger, Ashley; Tucker, Steven; Gurtov, Alia; Hlophe, Nompumelelo; Hunter, Rick; Morris, Hannah; Peixotto, Becca; Ramalepa, Maropeng; van Rooyen, Dirk; Tsikoane, Mathabela; Boshoff, Pedro; Dirks, Paul HGM; Berger, Lee R

2017-01-01

The Rising Star cave system has produced abundant fossil hominin remains within the Dinaledi Chamber, representing a minimum of 15 individuals attributed to Homo naledi. Further exploration led to the discovery of hominin material, now comprising 131 hominin specimens, within a second chamber, the Lesedi Chamber. The Lesedi Chamber is far separated from the Dinaledi Chamber within the Rising Star cave system, and represents a second depositional context for hominin remains. In each of three collection areas within the Lesedi Chamber, diagnostic skeletal material allows a clear attribution to H. naledi. Both adult and immature material is present. The hominin remains represent at least three individuals based upon duplication of elements, but more individuals are likely present based upon the spatial context. The most significant specimen is the near-complete cranium of a large individual, designated LES1, with an endocranial volume of approximately 610 ml and associated postcranial remains. The Lesedi Chamber skeletal sample extends our knowledge of the morphology and variation of H. naledi, and evidence of H. naledi from both recovery localities shows a consistent pattern of differentiation from other hominin species. DOI: http://dx.doi.org/10.7554/eLife.24232.001 PMID:28483039

Facility information system `SOINS-IIS`; Shisetsu joho kanri system `SOINS-IIS`

Energy Technology Data Exchange (ETDEWEB)

Shimaoka, S.; Watanabe, M.; Mizuno, Y. [Fuji Electric Co. Ltd., Tokyo (Japan)

1998-07-10

With the informatization in the industry, office space is becoming the center of business activities. Also as to the facility control, a facility control system is required which is added with functions of information service to users and the management support system, in addition to the conventional system used mainly for equipment maintenance. Fuji Electric Co. developed a facility information control system, SOINS-IIS (social information system-infrastructure information system), into which the above-mentioned functions were integrated. The features of the system were presented in examples of the introduction to Ichibankan, YRP (Yokosuka Research Park) Center and R and D Center, NTT DoCoMo. The system roughly has an information service function for facility users, function of management for office staff such as tenant management and bill management, management support function for facility owners and planning departments. Beside the above-mentioned functions, in case of YRP Center, for example, the system has functions of management of reservation of meeting rooms, etc., terminal display of common use information and terminal display of information, and many other management support functions. 10 figs.

Evaluation of the operational characteristics of a CT ionization chamber

International Nuclear Information System (INIS)

Maia, Ana F.; Caldas, Linda V.E.

2006-01-01

The most common ionization chamber used in computed tomography dosimetry is the 'pencil ionization chamber'. It is a special cylindrical dosimeter developed for attending computed tomography beams particularities. In this study, a Victoreen pencil ionization chamber was submitted to a set of tests for a detailed evaluation of its operational characteristics. Such as many kinds of detectors, especially field instruments, this ionization chamber had originally a preamplifier to keep it electrically more stable. In this study, the performance of the chamber was analyzed with the original preamplifier and after its removal, and the results were compared. The objective of the preamplifier removal was to enable connecting the chamber to other kinds of electrometers available in laboratories. The behavior of the pencil ionization chamber before and after the removal of the preamplifier was very similar, and the results obtained were always within the limits of international recommendations. The results obtained in both situations allow, if necessary, the preamplifier removal of the system without lack of precision in the measurements

A re-circulated toxicity exposure chamber to evaluate hydrocarbon dispersions

International Nuclear Information System (INIS)

Fuller, C.B.; Bonner, J.S.; Bujnoch, J.D.; Ussery, S.F.; Arrambide, G.; Sterling, M.C.

2002-01-01

Traditional toxicology methods are not suitable for evaluating chemically dispersed oil which exists mostly as a colloidal suspension and as dissolved fractions. A new toxicity exposure chamber was designed with separate chambers for scaled mixing and organism exposure. The design of the chamber incorporates continuous recirculation between the mixing and exposure chamber and an upward flow in the exposure chamber. The toxicity exposure system incorporates scalable and quantitative mixing inputs with real time particle size analysis and traditional petrochemistry methods to characterize the exposure regime. Changes in dispersion were successfully translated to the organism exposure regime. The study determined the petroleum toxicity with a juvenile marine test species. Low control mortality demonstrated the usefulness of the method for testing toxicity of colloidal oil suspensions. 20 refs., 1 tab., 4 figs

Design of hygrothermal detection and control intelligent system based on AVR-MCU in radon chamber

International Nuclear Information System (INIS)

Zheng Yongming; Fang Fang; Zhou Wei; Zheng Meiyang; Xu Jianyi

2006-01-01

The design of a new hygrothermal detection and control system based on AVR-MCU, which is used in minitype and medium-sized radon chamber, is introduced. The kernel of the interface among ATmega128 MCU, hygrothermal sensor, refrigeration and desiccation components is described. In addition, with the calculation of the control capability in theory, it comes to the conclusion that the design is feasible, and this control system not only can work in independence, but also can cooperate with PC by RS232 communication. (authors)

Component configuration control system development at EBR-II

International Nuclear Information System (INIS)

Monson, L.R.; Stratton, R.C.

1984-01-01

One ofthe major programs being pursued by the EBR-II Division of Argonne National Laboratory is to improve the reliability of plant control and protection systems. This effort involves looking closely at the present state of the art and needs associated with plant diagnostic, control and protection systems. One of the areas of development at EBR-II involves a component configuration control system (CCCS). This system is a computerized control and planning aid for the nuclear power operator

U.S. Chamber Adds Business Viewpoint on Schools' Quality

Science.gov (United States)

Archer, Jeff

2007-01-01

With a new and highly critical report card offering a business perspective on the effectiveness of state education systems, the U.S. Chamber of Commerce is pushing what it sees as a prescription for more innovative, efficient, and better-performing schools. For the chamber, the grades and policy platform further a concerted new effort to shape…

Change of Pressing Chamber Conicalness at Briquetting Process in Briquetting Machine Pressing Chamber

Directory of Open Access Journals (Sweden)

Peter Križan

2012-01-01

Full Text Available In this paper, we will present the impact of the conical shape of a pressing chamber, an important structural parameter. Besides the known impact of the technological parameters of pressing chambers, it is also very important to pay attention to their structural parameters. In the introduction, we present a theoretical analysis of pressing chamber conicalness. An experiment aimed at detecting this impact was performed at our institute, and it showed that increasing the conicalness of a pressing chamber improves the quality of the final briquettes. The conicalness of the pressing chamber has a significanteffect on the final briquette quality and on the construction of briquetting machines. The experimental findings presented here show the importance of this parameter in the briquetting process.

Status of COLDDIAG: A Cold Vacuum Chamber for Diagnostics

CERN Document Server

Gerstl, Stefan; Casalbuoni, Sara; Grau, Andreas; Hagelstein, Michael; Saez de Jauregui, David; Baglin, Vincent; Boffo, Cristian; Sikler, Gunther; Bradshaw, Thomas; Cimino, Roberto; Commisso, Mario; Spataro, Bruno; Clarke, James; Scott, Duncan; Cox, Matthew; Schouten, Jos; Jones, Roger; Shinton, Ian; Mostacci, Andrea; Wallen, Erik; Weigel, Ralf

2010-01-01

One of the still open issues for the development of superconducting insertion devices is the understanding of the beam heat load. With the aim of measuring the beam heat load to a cold bore and the hope to gain a deeper understanding in the beam heat load mechanisms, a cold vacuum chamber for diagnostics is under construction. The following diagnostics will be implemented: i) retarding field analyzers to measure the electron energy and flux, ii) temperature sensors to measure the total heat load, iii) pressure gauges, iv) and mass spectrometers to measure the gas content. The inner vacuum chamber will be removable in order to test different geometries and materials. This will allow the installation of the cryostat in different synchrotron light sources. COLDDIAG will be built to fit in a short straight section at ANKA. A first installation at the synchrotron light source Diamond is foreseen in June 2011. Here we describe the technical design report of this device and the planned measurements with beam.

Bluetooth Communication Interface for EEG Signal Recording in Hyperbaric Chambers.

Science.gov (United States)

Pastena, Lucio; Formaggio, Emanuela; Faralli, Fabio; Melucci, Massimo; Rossi, Marco; Gagliardi, Riccardo; Ricciardi, Lucio; Storti, Silvia F

2015-07-01

Recording biological signals inside a hyperbaric chamber poses technical challenges (the steel walls enclosing it greatly attenuate or completely block the signals as in a Faraday cage), practical (lengthy cables creating eddy currents), and safety (sparks hazard from power supply to the electronic apparatus inside the chamber) which can be overcome with new wireless technologies. In this technical report we present the design and implementation of a Bluetooth system for electroencephalographic (EEG) recording inside a hyperbaric chamber and describe the feasibility of EEG signal transmission outside the chamber. Differently from older systems, this technology allows the online recording of amplified signals, without interference from eddy currents. In an application of this technology, we measured EEG activity in professional divers under three experimental conditions in a hyperbaric chamber to determine how oxygen, assumed at a constant hyperbaric pressure of 2.8 ATA , affects the bioelectrical activity. The EEG spectral power estimated by fast Fourier transform and the cortical sources of the EEG rhythms estimated by low-resolution brain electromagnetic analysis were analyzed in three different EEG acquisitions: breathing air at sea level; breathing oxygen at a simulated depth of 18 msw, and breathing air at sea level after decompression.

Conceptual design study of the hylife lithium waterfall laser fusion chamber. FY 1978 annual report to Lawrence Livermore Laboratory

International Nuclear Information System (INIS)

1978-01-01

Conceptual design studies of the target chamber defined the general configuration and dimensions of the chamber and the inlet plenum, orifice plate, and nozzle plate concepts required to generate the desired lithium jet fall. Preliminary studies were performed of the target chamber interfaces with the liquid lithium supply system, the laser system, the pellet injection system, and the target chamber mounting and support system. Target chamber environmental effects resulting from typical thermonuclear burns were evaluated. The outlet region of the target chamber was outlined conceptually, and preliminary design considerations were given to the annular graphite reflector regions of the target chamber and the associated liquid lithium coolant passages

Experimental Verification of the Fission Chamber Gamma Signal Suppression by the Campbelling Mode

International Nuclear Information System (INIS)

Vermeeren, L.; Weber, M.; Oriol, L.; Breaud, S.; Filliatre, P.; Geslot, B.; Jammes, C.; Normand, S.; Lescop, B.

2011-01-01

For the on-line monitoring of high fast neutron fluxes in the presence of a strong thermal neutron component, SCK-CEN and CEA are jointly developing a Fast Neutron Detector System, based on 242 Pu fission chambers as sensors and including dedicated electronics and data processing systems. Irradiation tests in the BR2 reactor of 242 Pu fission chambers operating in current mode showed that in typical MTR conditions the fission chamber currents are dominated by the gamma contribution. In order to reduce the gamma contribution to the signal, it was proposed to use the fission chambers in Campbelling mode. An irradiation experiment in the BR2 reactor with a 242 Pu and a 235 U fission chamber, both equipped with a suitable cable for measurements in Campbelling mode, proved the effectiveness of the suppression of the gamma-induced signal component by the Campbelling mode: gamma contribution reduction factors of 26 for the 235 U fission chamber and more than 80 for the 242 Pu fission chamber were obtained. The experimental data also prove that photofission contributions are negligibly small. Consequently, in typical MTR conditions the gamma contribution to the fission chamber Campbelling signal can be neglected. (authors)

Micromachined filter-chamber array with passive valves for biochemical assays on beads

NARCIS (Netherlands)

Lichtenberg, Jan; Verpoorte, Elisabeth; De Rooij, Nico F.

2001-01-01

The filter-chamber array presented here enables a real-time parallel analysis of three different samples on beads in a volume of 3 nL, on a 1 cm2chip. The filter-chamber array is a system containing three filter-chambers, three passive valves at the inlet channels and a common outlet. The design

Dual-chamber inflatable oil boom

International Nuclear Information System (INIS)

Blair, R.M.; Tedeschi, E.T.

1993-01-01

An elongated floating material containment boom section is described having a normally vertical ballasted skirt depending from flotation means, and convertible from a flattened collapsed condition to a deployable condition wherein buoyancy chamber means extending along the upper edge of said skirt are inflated to expanded buoyant configuration, including: a gas-impervious sleeve extending along the upper edge of said normally vertical skirt forming a first outer collapsible and inflatable flotation chamber, a first inflation valve connecting the interior of said sleeve with the ambient atmosphere, through which gas under pressure may be introduced into said sleeve to inflate said first buoyant outer flotation chamber, elongated gas-impervious tube means positioned inside said outer flotation chamber and forming second collapsible and inflatable internal flotation bladder chamber means, second inflation valve means connecting the interior of said bladder means through said outer flotation chamber to the ambient atmosphere through which gas under pressure may be introduced into said bladder means to inflate it forming said second flotation chamber means inside said outer flotation chamber

Gridded ionization chamber and dual parameter measurement system for fast neutron-induced charged particles emission reaction

International Nuclear Information System (INIS)

Chen Yingtang; Qi Huiquan; Chen Zemin

1995-01-01

A twin ionization chamber with a common cathode and grids is described for (n,α), (n,p) studies. The chamber is used to determine the energy spectra and angular distribution of the charged particles emitted from the sample positioned on the cathode by dual parameter measurements of coinciding pulses from the anode and cathode of the ionization chamber. Pu α source is used to test the property of the chamber, an isotropic angular distribution is basically showed and the energy resolution is about 2%. This ionization chamber has already been applied to the studies of the 40 Ca(n,α) and 64 Zn(n,α) reactions

BEBC bubble chamber

CERN Multimedia

CERN PhotoLab

1972-01-01

Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

Development of mass-production technique of the ATLAS thin gap chamber in Japan

CERN Document Server

Tanaka, S; Ishii, K; Iwasaki, H; Arataki, Y; Bando, T; Homma, Y; Ishino, M; Kondo, T; Kobayashi, T; Kurashige, H; Mikenberg, G; Miyazaki, Y; Nakagawa, Y; Nanjo, H; Ikeno, M; Nozaki, M; Ochi, A; Sasaki, O; Shoa, M; Sugimoto, T; Takeda, H; Takeshita, T; Yokoyama, C

2004-01-01

The thin gap chambers (TGCs) are used for the muon trigger system in the end-cap regions of the ATLAS detector. As the anode-cathode distance is small, 1.4 mm, chamber flatness is essential to achieve a uniform gas gain over the chamber. The TGC mass production phase at High Energy Accelerator Research Organization (KEK) started in January 2001. In order to perform a stable production with high quality we developed a chamber closing system. When we glue two half- chambers together, we sandwich them with a granite table and an aluminum honeycomb panel that keep the chamber flat from both sides. By using silk screens, we also control the quantity of epoxy adhesive that affects the chamber thickness. Owing to these developments, we can achieve the flatness of less than 100 mu m. Uniformity of detection efficiency of the TGC is measured with a cosmic-ray test bench at Kobe University. We have tested 300 TGCs so far. Position dependence of the efficiency is measured with a granularity of 5 mm- by-5 mm. The average...

Data analysis for bubble chamber and hybrid systems

International Nuclear Information System (INIS)

Mermikides, M.E.

1981-01-01

The course will be mainly devoted to data-processing aspects of present-day bubble chamber experiments involving the use of external particle detectors. Present trends will be briefly reviewed from the point of view of instrumentation and trigger conditions employed to realize the physics objectives. The lectures will include a discussion of software aids and disciplines for program maintenance and development and the management of data structures. (orig.)

A closed unventilated chamber for the measurement of transepidermal water loss.

Science.gov (United States)

Nuutinen, Jouni; Alanen, Esko; Autio, Pekka; Lahtinen, Marjo-Riitta; Harvima, Ilkka; Lahtinen, Tapani

2003-05-01

Open chamber systems for measuring transepidermal water loss (TEWL) have limitations related to ambient and body-induced airflows near the probe, probe size, measurement sites and angles, and measurement range. The aim of the present investigation was to develop a closed chamber system for the TEWL measurement without significant blocking of normal evaporation through the skin. Additionally, in order to use the evaporimeter to measure evaporation rates through other biological and non-biological specimens and in the field applications, a small portable, battery-operated device was a design criteria. A closed unventilated chamber (inner volume 2.0 cm(3) was constructed. For the skin measurement, the chamber with one side open (open surface area 1.0 cm(2) is placed on the skin. The skin application time was investigated at low and high evaporation rates in order to assess the blocking effect of the chamber on normal evaporation. From the rising linear part of the relative humidity (RH) in the chamber the slope was registered. The slope was calibrated into a TEWL value by evaporating water at different temperatures and measuring the water loss of heated samples with a laboratory scale. The closed chamber evaporation technique was compared with a conventional evaporimeter based on an open chamber method (DermaLab), Cortex Technology, Hadsund, Denmark). The reproducibility of the closed chamber method was measured with the water samples and with volar forearm and palm of the hand in 10 healthy volunteers. The skin application time varied between 7 and 9 s and the linear slope region between 3 and 5 s at the evaporation rates of 3-220 g/m(2) h. A correlation coefficient between the TEWL value from the closed chamber measurements and the readings of the laboratory scale was 0.99 (P measurements with the water samples was 4.0% at the evaporation rate of 40 g/m(2) h. A correlation coefficient of the TEWL values between the closed chamber and open chamber measurements was 0

EBR-II Cover Gas Cleanup System upgrade process control system structure

International Nuclear Information System (INIS)

Carlson, R.B.; Staffon, J.D.

1992-01-01

The Experimental Breeder Reactor II (EBR-II) Cover Gas Cleanup System (CGCS) control system was upgraded in 1991 to improve control and provide a graphical operator interface. The upgrade consisted of a main control computer, a distributed control computer, a front end input/output computer, a main graphics interface terminal, and a remote graphics interface terminal. This paper briefly describes the Cover Gas Cleanup System and the overall control system; describes the main control computer hardware and system software features in more detail; and, then, describes the real-time control tasks, and how they interact with each other, and how they interact with the operator interface task

An open-walled ionization chamber appropriate to tritium monitoring for glovebox

International Nuclear Information System (INIS)

Chen Zhilin; Chang Ruiming; Mu Long; Song Guoyang; Wang Heyi; Wu Guanyin; Wei Xiye

2010-01-01

An open-walled ionization chamber is developed to monitor the tritium concentration in gloveboxes in tritium processing systems. Two open walls are used to replace the sealed wall in common ionization chambers, through which the tritium gas can diffuse into the chamber without the aid of pumps and pipelines. Some basic properties of the chamber are examined to evaluate its performance. Results turn out that an open-walled chamber of 1 l in volume shows a considerably flat plateau over 700 V for a range of tritium concentration. The chamber also gives a good linear response to gamma fields over 4 decades under a pressure condition of 1 atm. The pressure dependence characteristics show that the ionization current is only sensitive at low pressures. The pressure influence becomes weaker as the pressure increases mainly due to the decrease in the mean free path of β particles produced by tritium decay. The minimum detection limit of the chamber is 3.7x10 5 Bq/m 3 .

Vacuum Chambers for LEP sections

CERN Multimedia

1983-01-01

The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

Procedure for physicist's scanning in the image processing system of bubble chambers

International Nuclear Information System (INIS)

Gritsaenko, I.A.; Petrovykh, L.P.; Petrovykh, Yu.L.; Fenyuk, A.B.

1984-01-01

The algorithm of the program of physicist's scanning for data processing from photo images in experiments using bubble chambers is described. The program allows one to perform sorting or selection of specific events for subsequent processing and identification of separate particles by bubble density along the track or by the character of the decay. The fraction of protons separated automatically constituted 97%. The program has been used for processing 50 thousand events at the BEBC chamber

Reference ionization chamber

International Nuclear Information System (INIS)

Golnik, N.; Zielczynski, M.

1999-01-01

The paper presents the design of ionization chamber devoted for the determination of the absolute value of the absorbed dose in tissue-equivalent material. The special attention was paid to ensure that the volume of the active gas cavity was constant and well known. A specific property of the chamber design is that the voltage insulators are 'invisible' from any point of the active volume. Such configuration ensures a very good time stability of the electrical field and defines the active volume. The active volume of the chamber was determined with accuracy of 0.3%. This resulted in accuracy of 0.8% in determination of the absorbed dose in the layer of material adherent to the gas cavity. The chamber was applied for calibration purposes at radiotherapy facility in Joint Institute for Nuclear Research in Dubna (Russia) and in the calibration laboratory of the Institute of Atomic Energy in Swierk. (author)

A multi-component parallel-plate flow chamber system for studying the effect of exercise-induced wall shear stress on endothelial cells.

Science.gov (United States)

Wang, Yan-Xia; Xiang, Cheng; Liu, Bo; Zhu, Yong; Luan, Yong; Liu, Shu-Tian; Qin, Kai-Rong

2016-12-28

In vivo studies have demonstrated that reasonable exercise training can improve endothelial function. To confirm the key role of wall shear stress induced by exercise on endothelial cells, and to understand how wall shear stress affects the structure and the function of endothelial cells, it is crucial to design and fabricate an in vitro multi-component parallel-plate flow chamber system which can closely replicate exercise-induced wall shear stress waveforms in artery. The in vivo wall shear stress waveforms from the common carotid artery of a healthy volunteer in resting and immediately after 30 min acute aerobic cycling exercise were first calculated by measuring the inner diameter and the center-line blood flow velocity with a color Doppler ultrasound. According to the above in vivo wall shear stress waveforms, we designed and fabricated a parallel-plate flow chamber system with appropriate components based on a lumped parameter hemodynamics model. To validate the feasibility of this system, human umbilical vein endothelial cells (HUVECs) line were cultured within the parallel-plate flow chamber under abovementioned two types of wall shear stress waveforms and the intracellular actin microfilaments and nitric oxide (NO) production level were evaluated using fluorescence microscope. Our results show that the trends of resting and exercise-induced wall shear stress waveforms, especially the maximal, minimal and mean wall shear stress as well as oscillatory shear index, generated by the parallel-plate flow chamber system are similar to those acquired from the common carotid artery. In addition, the cellular experiments demonstrate that the actin microfilaments and the production of NO within cells exposed to the two different wall shear stress waveforms exhibit different dynamic behaviors; there are larger numbers of actin microfilaments and higher level NO in cells exposed in exercise-induced wall shear stress condition than resting wall shear stress condition

Plastic flashtube chambers

International Nuclear Information System (INIS)

Frisken, W.R.

1977-01-01

A brief discussion is given of the use and operation of plastic flashtube chambers. Gas leaks, electric pulsing, the glow discharge, and readout methods are considered. Three distinct problems with high rate applications deal with resolving time, dead time, and polarization/neutralization of the chamber

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.

Calibration of a 4π-γ well-type ionization chamber system for measuring of the radionuclides activity

International Nuclear Information System (INIS)

Dias, M.S.

1978-01-01

The calibration of a 4π well-type ionization Chamber System installed at the Laboratorio de Metrologia Nuclear, of the Instituto de Energia Atomica of Sao Paulo used for of the activity determination of radioactive solutions is descrided. The determination can be performed by two methods: 1) Direct Method, comparing the ionization Chamber response for solutions of unknown activity against that obtained with a solution which is standardized by the Absolute 4πβγ Coincidence Method. By this method the following radionuclides are standardized: 241 Am, 139 Ce, 198 Au, 22 Na, 134 Cs, 54 Mn, 60 Co, 42 K, 24 Na. In this case, the accuracy achieved is about 0.2 to 0,4%. 2) Indirect Method, by means of curves of relative beta or gama efficiency, which were determined in this work. This method can be applied for those radionuclides not included in the direct method. In this case, the accuracy depends on the gama energy range of the curves and on the accuracy of the absolute gama intensities, taken from the literature. In general the uncertainty is greater than the direct method, but values of 0,2% can be achieved in favourable cases. The upper and lower limits of Activity that can be measured depend on the radionuclide. These limits are from a few micro-curies to many mili-curies, which are satisfactory for most purposes. The sample preparation is simple and the time spent in the measurement is, in general, restricted to a few minutes. These are some of the advantages of this ionization Chamber System in comparison with other systems [pt

Evaluation of RF Anechoic Chamber Fire Protection Systems

Science.gov (United States)

1980-07-01

references are provided in Appendices A and B of this report. A review of advertising and manufacturer directories indi- cates that there are only three...have a considerably greater reliability and freedom from false (or unwanted) alarms than common detectors sold for the compliance market . During a one...34. Of greater importance is the fact that light source and photocell can be nestled in the base juncture of adjacent cones, offering less chamber

Wire chambers: Trends and alternatives

Energy Technology Data Exchange (ETDEWEB)

Regler, Meinhard

1992-05-15

The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!.

Design, construction and testing of a radon experimental chamber

International Nuclear Information System (INIS)

Chavez B, A.; Balcazar G, M.

1991-10-01

To carry out studies on the radon behavior under controlled and stable conditions it was designed and constructed a system that consists of two parts: a container of mineral rich in Uranium and an experimentation chamber with radon united one to the other one by a step valve. The container of uranium mineral approximately contains 800 gr of uranium with a law of 0.28%; the radon gas emanated by the mineral is contained tightly by the container. When the valve opens up the radon gas it spreads to the radon experimental chamber; this contains 3 accesses that allow to install different types of detectors. The versatility of the system is exemplified with two experiments: 1. With the radon experimental chamber and an associated spectroscopic system, the radon and two of its decay products are identified. 2. The design of the system allows to couple the mineral container to other experimental geometries to demonstrate this fact it was coupled and proved a new automatic exchanger system of passive detectors of radon. The results of the new automatic exchanger system when it leave to flow the radon freely among the container and the automatic exchanger through a plastic membrane of 15 m. are shown. (Author)

Compact multiwire proportional chambers and electronics for the crystal ball detector

International Nuclear Information System (INIS)

Gaiser, J.E.; Liberman, A.D.; Rolfe, J.

1978-01-01

A double gap of cylindrical proportional chambers has been designed and built for use with a large solid angle, modular NaI(Tl) array (The Crystal Ball). The chambers are constructed of three coaxial foam-epoxy shells, covered with an aluminum-mylar laminate. One of the high voltage cathodes in each chamber has been photo-etched to produce a pattern of stripes and precise position measurements of tracks passing transverse to the chamber axis are found by pulse height analyzing the shaped and amplified induced strip signals. Performance of the chamber using both the strip signals and the sense wire readout is presented. The design of both the signal handling electronics and the digital portions of the systems is discussed

Prototype multiwire proportional chamber

CERN Multimedia

1975-01-01

Chambers of this type were initially developed within the Alpha project (finally not approved). They were designed such to minimize the radiation length with a view to a mass spectrometer of high resolution meant to replace the Omega detector. The chambers were clearly forerunners for the (drift) chambers later built for R606 with the novel technique of crimping the wires. See also photo 7510039X.

Miniature ionization chamber

International Nuclear Information System (INIS)

Alexeev, V.I.; Emelyanov, I.Y.; Ivanov, V.M.; Konstantinov, L.V.; Lysikov, B.V.; Postnikov, V.V.; Rybakov, J.V.

1976-01-01

A miniature ionization chamber having a gas-filled housing which accommodates a guard electrode made in the form of a hollow perforated cylinder is described. The cylinder is electrically associated with the intermediate coaxial conductor of a triaxial cable used as the lead-in of the ionization chamber. The gas-filled housing of the ionization chamber also accommodates a collecting electrode shaped as a rod electrically connected to the center conductor of the cable and to tubular members. The rod is disposed internally of the guard electrode and is electrically connected, by means of jumpers passing through the holes in the guard electrode, to the tubular members. The tubular members embrace the guard electrode and are spaced a certain distance apart along its entire length. Arranged intermediate of these tubular members are spacers secured to the guard electrode and fixing the collecting electrode throughout its length with respect to the housing of the ionization chamber

Direct measurement of the impulse in a magnetic thrust chamber system for laser fusion rocket

Energy Technology Data Exchange (ETDEWEB)

Maeno, Akihiro; Yamamoto, Naoji; Nakashima, Hideki [Interdisciplinary Graduate School of Engineering Science, Kyushu University, 6-1 Kasuga-kouen, Kasuga, Fukuoka 816-8580 (Japan); Fujioka, Shinsuke; Johzaki, Tomoyuki [Institute of Laser Engineering, Osaka University, Suita, Osaka 565-087 (Japan); Mori, Yoshitaka [Graduate School for the Creation of New Photonics Industries, Hamamatsu, Shizuoka 431-1202 (Japan); Sunahara, Atsushi [Institute for Laser Technology, Suita, Osaka 565-087 (Japan)

2011-08-15

An experiment is conducted to measure an impulse for demonstrating a magnetic thrust chamber system for laser fusion rocket. The impulse is produced by the interaction between plasma and magnetic field. In the experiment, the system consists of plasma and neodymium permanent magnets. The plasma is created by a single-beam laser aiming at a polystyrene spherical target. The impulse is 1.5 to 2.2 {mu}Ns by means of a pendulum thrust stand, when the laser energy is 0.7 J. Without magnetic field, the measured impulse is found to be zero. These results indicate that the system for generating impulse is working.

Experimental verification of the fission chamber gamma signal suppression by the Campbelling mode

Energy Technology Data Exchange (ETDEWEB)

Vermeeren, L.; Weber, M. [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium); Oriol, L.; Breaud, S.; Filliatre, P.; Geslot, B.; Jammes, C. [CEA, Centre de Cadarache, F-13109 Saint-Paul-lez-Durance (France); Normand, S.; Lescop, B. [CEA, Centre de Saclay, F-91191 Gif sur Yvette Cedex (France)

2009-07-01

For the on-line monitoring of high fast neutron fluxes in the presence of a strong thermal neutron component, SCK-CEN and CEA are jointly developing a Fast Neutron Detector System, based on {sup 242}Pu fission chambers as sensors and including dedicated electronics and data processing systems. Irradiation tests in the BR2 reactor of {sup 242}Pu fission chambers operating in current mode showed that in typical MTR (Materials Test Reactors) conditions the fission chamber currents are dominated by the gamma contribution. In order to reduce the gamma contribution to the signal, it was proposed to use the fission chambers in Campbelling mode. An irradiation experiment in the BR2 reactor with a {sup 242}Pu and a {sup 235}U fission chamber, both equipped with a suitable cable for measurements in Campbelling mode, proved the effectiveness of the suppression of the gamma-induced signal component by the Campbelling mode: gamma contribution reduction factors of 26 for the {sup 235}U fission chamber and more than 80 for the {sup 242}Pu fission chamber were obtained. The experimental data also prove that photofission contributions are negligibly small. Consequently, in typical MTR conditions the gamma contribution to the fission chamber Campbelling signal can be neglected. (authors)

Measurements of x-ray scattering from accelerator vacuum chamber surfaces, and comparison with an analytical model

Directory of Open Access Journals (Sweden)

G. F. Dugan

2015-04-01

Full Text Available This paper compares measurements and calculations of scattering of photons from technical vacuum chamber surfaces typical of accelerators. Synchrotron radiation generated by a charged particle beam in the accelerator is either absorbed, specularly reflected, or scattered by the vacuum chamber surface. This phenomenon has important implications on the operation of the accelerator. Measurements of photon scattering were made at the BESSY-II synchrotron radiation facility using samples of aluminum vacuum chamber from Cornell electron storage ring (CESR. A description of the analytic model used in the calculation is given, which takes into account the reflectivity of the material, the surface features of the sample, the wavelengths and the incident angles of the photons. The surface properties used in these calculations were obtained from measurements made from an atomic force microscope.

Wire chambers: Trends and alternatives

International Nuclear Information System (INIS)

Regler, Meinhard

1992-01-01

The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!

A new plant chamber facility PLUS coupled to the atmospheric simulation chamber SAPHIR

Science.gov (United States)

Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

2015-11-01

A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been build and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees are mixed with synthetic air and are transferred to the SAPHIR chamber where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOC) can be studied in detail. In PLUS all important enviromental parameters (e.g. temperature, PAR, soil RH etc.) are well-controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leafes of the plants is constructed such that gases are exposed to FEP Teflon film and other Teflon surfaces only to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 LED panels which have an emission strength up to 800 μmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOC) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light and temperature dependent BVOC emissions are studied using six Quercus Ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus Ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental set up and the utility of the newly added plant chamber.

A new plant chamber facility, PLUS, coupled to the atmosphere simulation chamber SAPHIR

Science.gov (United States)

Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

2016-03-01

A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been built and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow-through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees is mixed with synthetic air and transferred to the SAPHIR chamber, where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOCs) can be studied in detail. In PLUS all important environmental parameters (e.g., temperature, photosynthetically active radiation (PAR), soil relative humidity (RH)) are well controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leaves of the plants is constructed such that gases are exposed to only fluorinated ethylene propylene (FEP) Teflon film and other Teflon surfaces to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 light-emitting diode (LED) panels, which have an emission strength up to 800 µmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOCs) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light- and temperature- dependent BVOC emissions are studied using six Quercus ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental setup and the utility of the newly added plant chamber.

Towards new analog read-out electronics for the HADES drift chamber system

Energy Technology Data Exchange (ETDEWEB)

Wiebusch, Michael [Goethe-Universitaet, Frankfurt (Germany); Collaboration: HADES-Collaboration

2016-07-01

Track reconstruction in HADES is realized with 24 planar, low-mass drift chambers (MDC). About 27000 drift cells provide precise spatial information of track hit points together with energy loss information, serving for particle ID. In order to handle high rates and track densities required at the future SIS100 accelerator at FAIR, an upgrade of the MDC system is necessary, i.e. by receiving additional redundant layers of drift cells in front of the magnet. This involves new front-end electronics, as the original analog read-out ASIC (ASD8) is no longer in stock and cannot be produced due to its legacy silicon process. Employing new FEE would allow to further increase the sensitivity, e.g. providing additional valuable information for the analysis. This contribution presents a market analysis of alternative state-of-the-art technologies for the analog read-out of drift chambers. Test procedures to evaluate the suitability for the HADES MDCs are discussed and preliminary results are shown. Emphasis is put on the benefits and possible implementations of using two separate analog channels for reading out a sense wire, i.e. a fast amplifier with a discriminator for recording the arrival time of the signal pulse and a slow integrating amplifier with a time-over-threshold discriminator to measure the total charge of the pulse.

Automated System for Control of the Vacuum Diagnostic System for the TJ-II

International Nuclear Information System (INIS)

Lopez Sanchez, A.; Montoro Peinado, A.; Encabo Fernandez, J.; Gama de la Serrano, J.; Sanchez Sarabia, E.

1999-12-01

This report describes the monitoring and remote control systems belonging to the high vacuum systems of the TJ-II diagnostics. These systems are part of each diagnostic and their control has been integrated into the automata that carries out this task. All the controllers are connected through a Profibus network, so as to interchange data between themselves as well as between the general system of TJ-II. (Author)

Directed Energy Anechoic Chamber

Data.gov (United States)

Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

System modeling and simulation at EBR-II

International Nuclear Information System (INIS)

Dean, E.M.; Lehto, W.K.; Larson, H.A.

1986-01-01

The codes being developed and verified using EBR-II data are the NATDEMO, DSNP and CSYRED. NATDEMO is a variation of the Westinghouse DEMO code coupled to the NATCON code previously used to simulate perturbations of reactor flow and inlet temperature and loss-of-flow transients leading to natural convection in EBR-II. CSYRED uses the Continuous System Modeling Program (CSMP) to simulate the EBR-II core, including power, temperature, control-rod movement reactivity effects and flow and is used primarily to model reactivity induced power transients. The Dynamic Simulator for Nuclear Power Plants (DSNP) allows a whole plant, thermal-hydraulic simulation using specific component and system models called from libraries. It has been used to simulate flow coastdown transients, reactivity insertion events and balance-of-plant perturbations

Measurement of transepidermal water loss (TEWL) in cats with experimental skin barrier dysfunction using a closed chamber system.

Science.gov (United States)

Momota, Yutaka; Shimada, Kenichiro; Gin, Azusa; Matsubara, Takako; Azakami, Daigo; Ishioka, Katsumi; Nakamura, Yuka; Sako, Toshinori

2016-10-01

A closed chamber evaporimeter is suitable for measuring transepidermal water loss (TEWL) in cats because of the compact device size, tolerance to sudden movement and short measuring time. TEWL is a representative parameter for skin barrier dysfunction, which is one of the clinical signs of atopic dermatitis in humans and dogs. Measurement of feline TEWL has been reported, but applicability of this parameter has not been validated. The aims of this study were to determine if tape stripping is a valid experimental model in cats for studying TEWL and to determine if a closed chambered system is a suitable measurement tool for cats. Ten clinically normal cats. In order to evaluate variation of the measured values, TEWL was measured at the right and left side of the three clipped regions (axillae, lateral thigh and groin). Subsequently, TEWL was measured using sequential tape stripping of the stratum corneum as a model of acute barrier disruption. The variations between both sides of the three regions showed no significant difference. Sequential tape stripping was associated with increasing values for TEWL. Feline TEWL was shown to reflect changes in the skin barrier in an experimental model using a closed chamber system and has the potential for evaluating skin barrier function in cats with skin diseases. © 2016 ESVD and ACVD.

Streamer chamber: pion decay

CERN Multimedia

1992-01-01

The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

PS wire chamber

CERN Multimedia

1970-01-01

A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Directional muon jet chamber for a muon collider (Groovy Chamber)

International Nuclear Information System (INIS)

Atac, M.

1996-10-01

A directional jet drift chamber with PAD readout is proposed here which can select vertex originated muons within a given time window and eliminate those muons which primarily originate upstream, using only a PAD readout. Drift time provides the Z-coordinate, and the center of gravity of charge distribution provides the r-ψ coordinates. Directionality at the trigger level is obtained by the timing measurement from the PAD hits within a given time window. Because of the long drift time between the bunch crossings, a muon collider enables one to choose a drift distance in the drift chamber as long as 50 cm. This is an important factor in reducing cost of drift chambers which have to cover relatively large areas

Pencil-shaped radiation detection ionization chamber

International Nuclear Information System (INIS)

Suzuki, A.

1979-01-01

A radiation detection ionization chamber is described. It consists of an elongated cylindrical pencil-shaped tubing forming an outer wall of the chamber and a center electrode disposed along the major axis of the tubing. The length of the chamber is substantially greater than the diameter. A cable connecting portion at one end of the chamber is provided for connecting the chamber to a triaxial cable. An end support portion is connected at the other end of the chamber for supporting and tensioning the center electrode. 17 claims

The BEAST II Experiment at Belle II. Characterization of the commissioning detector system for SuperKEKB

Energy Technology Data Exchange (ETDEWEB)

Ahlburg, Patrick; Eyring, Andreas; Filimonov, Viacheslav; Krueger, Hans; Mari, Laura; Marinas, Carlos; Pohl, David-Leon; Wermes, Norbert; Dingfelder, Jochen [University of Bonn (Germany)

2016-07-01

Before the upgraded vertex detector for the Belle II experiment at the SuperKEKB collider in Japan will be installed, a dedicated detector system for machine commissioning (BEAST II) will be employed. One of its main objectives is to measure and characterize the different background types in order to ensure a safe environment before the installation of the actual silicon detector systems close to the interaction point. FANGS, a detector system at BEAST II, based on ATLAS-IBL front-end electronics and planar silicon sensors is currently being developed for this purpose. The unique feature of this detector system is the high energy resolution achieved by using an external FPGA clock to sample the time-over-threshold signal, while keeping the excellent timing properties. The complete detector system is presented in this talk.

Tasks related to increase of RA reactor exploitation and experimental potential, 01. Designing the protection chamber in the RA reactor hall for handling the radioactive experimental equipment (I-II) Part II, Vol. II; Radovi na povecanju eksploatacionih i eksperimentalnih mogucnosti reaktora RA, 01. Projektovanje zastitne komore u hali reaktora RA za rad sa aktivnim eksperimentalnim uredjajima (I-II), II Deo, Album II

Energy Technology Data Exchange (ETDEWEB)

Pavicevic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1963-07-15

This second volume of the project for construction of the protection chamber in the RA reactor hall for handling the radioactive devices includes the technical description of the chamber, calculation of the shielding wall thickness, bottom lead plate, horizontal stability of the chamber, cost estimation, and the engineering drawings.

Dual chamber system providing simultaneous etch and deposition on opposing substrate sides for growing low defect density epitaxial layers

Science.gov (United States)

Kulkarni, Nagraj S [Knoxville, TN; Kasica, Richard J. ,

2011-03-08

A dual-chamber reactor can include a housing enclosing a volume having a divider therein, where the divider defines a first chamber and a second chamber. The divider can include a substrate holder that supports at least one substrate and exposes a first side of the substrate to the first chamber and a second side of the substrate to the second chamber. The first chamber can include an inlet for delivering at least one reagent to the first chamber for forming a film on the first side of the substrate, and the second chamber can include a removal device for removing material from the second side of the substrate.

Improvement of Swirl Chamber Structure of Swirl-Chamber Diesel Engine Based on Flow Field Characteristics

Directory of Open Access Journals (Sweden)

Wenhua Yuan

2014-10-01

Full Text Available In order to improve combustion characteristic of swirl chamber diesel engine, a simulation model about a traditional cylindrical flat-bottom swirl chamber turbulent combustion diesel engine was established within the timeframe of the piston motion from the bottom dead centre (BDC to the top dead centre (TDC with the fluent dynamic mesh technique and flow field vector of gas in swirl chamber and cylinder; the pressure variation and temperature variation were obtained and a new type of swirl chamber structure was proposed. The results reveal that the piston will move from BDC; air in the cylinder is compressed into the swirl chamber by the piston to develop a swirl inside the chamber, with the ongoing of compression; the pressure and temperature are also rising gradually. Under this condition, the demand of diesel oil mixing and combusting will be better satisfied. Moreover, the new structure will no longer forma small fluid retention zone at the lower end outside the chamber and will be more beneficial to the mixing of fuel oil and air, which has presented a new idea and theoretical foundation for the design and optimization of swirl chamber structure and is thus of good significance of guiding in this regard.

Reaction Rate Benchmark Experiments with Miniature Fission Chambers at the Slovenian TRIGA Mark II Reactor

Science.gov (United States)

Štancar, Žiga; Kaiba, Tanja; Snoj, Luka; Barbot, Loïc; Destouches, Christophe; Fourmentel, Damien; Villard, Jean-François AD(; )

2018-01-01

A series of fission rate profile measurements with miniature fission chambers, developed by the Commisariat á l'énergie atomique et auxénergies alternatives, were performed at the Jožef Stefan Institute's TRIGA research reactor. Two types of fission chambers with different fissionable coating (235U and 238U) were used to perform axial fission rate profile measurements at various radial positions and several control rod configurations. The experimental campaign was supported by an extensive set of computations, based on a validated Monte Carlo computational model of the TRIGA reactor. The computing effort included neutron transport calculations to support the planning and design of the experiments as well as calculations to aid the evaluation of experimental and computational uncertainties and major biases. The evaluation of uncertainties was performed by employing various types of sensitivity analyses such as experimental parameter perturbation and core reaction rate gradient calculations. It has been found that the experimental uncertainty of the measurements is sufficiently low, i.e. the total relative fission rate uncertainty being approximately 5 %, in order for the experiments to serve as benchmark experiments for validation of fission rate profiles. The effect of the neutron flux redistribution due to the control rod movement was studied by performing measurements and calculations of fission rates and fission chamber responses in different axial and radial positions at different control rod configurations. It was confirmed that the control rod movement affects the position of the maximum in the axial fission rate distribution, as well as the height of the local maxima. The optimal detector position, in which the redistributions would have minimum effect on its signal, was determined.

Pattern-recognition system application to EBR-II plant-life extension

International Nuclear Information System (INIS)

King, R.W.; Radtke, W.H.; Mott, J.E.

1988-01-01

A computer-based pattern-recognition system, the System State Analyzer (SSA), is being used as part of the EBR-II plant-life extension program for detection of degradation and other abnormalities in plant systems. The SSA is used for surveillance of the EBR-II primary system instrumentation, primary sodium pumps, and plant heat balances. Early results of this surveillance indicate that the SSA can detect instrumentation degradation and system performance degradation over varying time intervals, and can provide derived signal values to replace signals from failed critical sensors. These results are being used in planning for extended-life operation of EBR-II

The D0 run II trigger system

International Nuclear Information System (INIS)

Schwienhorst, Reinhard; Michigan State U.

2004-01-01

The D0 detector at the Fermilab Tevatron was upgraded for Run II. This upgrade included improvements to the trigger system in order to be able to handle the increased Tevatron luminosity and higher bunch crossing rates compared to Run I. The D0 Run II trigger is a highly exible system to select events to be written to tape from an initial interaction rate of about 2.5 MHz. This is done in a three-tier pipelined, buffered system. The first tier (level 1) processes fast detector pick-off signals in a hardware/firmware based system to reduce the event rate to about 1. 5kHz. The second tier (level 2) uses information from level 1 and forms simple Physics objects to reduce the rate to about 850 Hz. The third tier (level 3) uses full detector readout and event reconstruction on a filter farm to reduce the rate to 20-30 Hz. The D0 trigger menu contains a wide variety of triggers. While the emphasis is on triggering on generic lepton and jet final states, there are also trigger terms for specific final state signatures. In this document we describe the D0 trigger system as it was implemented and is currently operating in Run II

Proposal for the award of a contract for the supply of ceramic vacuum chambers for the LHC beam dumping system

CERN Document Server

2001-01-01

This document concerns the award of a contract for the supply of ceramic vacuum chambers for the LHC beam dumping system. Following a market survey carried out among 22 firms in seven Member States and one firm in the United States, a call for tenders (IT-2765/SL/LHC) was sent on 13 September 2001 to one firm. By the closing date, CERN had received a tender. The Finance Committee is invited to agree to the negotiation of a contract with KYOCERA FINECERAMICS (DE) for the supply of 36 ceramic vacuum chambers for the LHC beam dumping system for a total amount of 681 530 euros (1 013 094 Swiss francs), not subject to revision, with options for six additional vacuum chambers, for an additional amount of 146 768 euros (218 171 Swiss francs), not subject to revision, bringing the total amount to 828 298 euros (1 231 265 Swiss francs), not subject to revision. The rate of exchange which has been used is that applying on the closing date of the call for tenders. The firm has indicated the following distribution by cou...

Large-Scale Production of Monitored Drift Tube Chambers for the ATLAS Muon Spectrometer

CERN Document Server

Bauer, F.; Kortner, O; Kroha, H; Manz, A; Mohrdieck, S; Richter, R; Zhuravlov, V

2016-01-01

Precision drift tube chambers with a sense wire positioning accuracy of better than 20 microns are under construction for the ATLAS muon spectrometer. 70% of the 88 large chambers for the outermost layer of the central part of the spectrometer have been assembled. Measurements during chamber construction of the positions of the sense wires and of the sensors for the optical alignment monitoring system demonstrate that the requirements for the mechanical precision of the chambers are fulfilled.

A whole-tree chamber system for examining tree-level physiological responses of field-grown trees to environmental variation and climate change.

Science.gov (United States)

Medhurst, Jane; Parsby, Jan; Linder, Sune; Wallin, Göran; Ceschia, Eric; Slaney, Michelle

2006-09-01

A whole-tree chamber (WTC) system was installed at Flakaliden in northern Sweden to examine the long-term physiological responses of field-grown 40-year-old Norway spruce trees [Picea abies (L.) Karst.] to climate change. The WTCs were designed as large cuvettes to allow the net tree-level CO(2) and water fluxes to be measured on a continuous basis. A total of 12 WTCs were used to impose combinations of atmospheric carbon dioxide concentration, [CO(2)], and air temperature treatments. The air inside the ambient and elevated [CO(2)] WTCs was maintained at 365 and 700 micromol mol(-1), respectively. The air temperature inside the ambient temperature WTCs tracked air temperature outside the WTCs. Elevated temperatures were altered on a monthly time-step and ranged between +2.8 and +5.6 degrees C above ambient temperature. The system allowed continuous, long-term measurement of whole-tree photosynthesis, night-time respiration and transpiration. The performance of the WTCs was assessed using winter and spring data sets. The ability of the WTC system to measure tree-level physiological responses is demonstrated. All WTCs displayed a high level of control over tracking of air temperatures. The set target of 365 micromol mol(-1) in the ambient [CO(2)] chambers was too low to be maintained during winter because of tree dormancy and the high natural increase in [CO(2)] over winter at high latitudes such as the Flakaliden site. Accurate control over [CO(2)] in the ambient [CO(2)] chambers was restored during the spring and the system maintained the elevated [CO(2)] target of 700 micromol mol(-1) for both measurement periods. Air water vapour deficit (VPD) was accurately tracked in ambient temperature WTCs. However, as water vapour pressure in all 12 WTCs was maintained at the level of non-chambered (reference) air, VPD of elevated temperature WTCs was increased.

Sorption of Hg(II and Pb(II Ions on Chitosan-Iron(III from Aqueous Solutions: Single and Binary Systems

Directory of Open Access Journals (Sweden)

Byron Lapo

2018-03-01

Full Text Available The present work describes the study of mercury Hg(II and lead Pb(II removal in single and binary component systems into easily prepared chitosan-iron(III bio-composite beads. Scanning electron microscopy and energy-dispersive X-ray (SEM-EDX analysis, Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA and point of zero charge (pHpzc analysis were carried out. The experimental set covered pH study, single and competitive equilibrium, kinetics, chloride and sulfate effects as well as sorption–desorption cycles. In single systems, the Langmuir nonlinear model fitted the experimental data better than the Freundlich and Sips equations. The sorbent material has more affinity to Hg(II rather than Pb(II ions, the maximum sorption capacities were 1.8 mmol·g−1 and 0.56 mmol·g−1 for Hg(II and Pb(II, respectively. The binary systems data were adjusted with competitive Langmuir isotherm model. The presence of sulfate ions in the multicomponent system [Hg(II-Pb(II] had a lesser impact on the sorption efficiency than did chloride ions, however, the presence of chloride ions improves the selectivity towards Hg(II ions. The bio-based material showed good recovery performance of metal ions along three sorption–desorption cycles.

Establishment of a radon test chamber

International Nuclear Information System (INIS)

Chen Chingjiang; Liu Chichang; Lin Yuming

1993-01-01

A walk-in type radon test chamber of 23 m 3 has been built for testing and calibration of radon measurement instruments. The environmental conditions of the test chamber can be varied within a wide range of values. The design objectives specification, monitoring instruments and testing results of this chamber are discussed. This test chamber is available for domestic radon researchers and its accuracy can be traced to the international standard. A routine intercomparison study will be held annually by using this chamber. Other tests like radon progeny and thoron standard may also be performed in this chamber. (1 fig.)

The User-friendly On-Line Diffusion Chamber

CERN Document Server

Aviles Acosta, Jaime

2015-01-01

The On-Line Diffusion Chamber is a stand-alone apparatus built to carry out short-live radiotracer diffusion studies. The availability of the on-demand production of isotopes in the ISOLDE facility, and the design of the apparatus to streamline the implantation process, annealing treatment, ion gun ablation with a tape transport system, and radiation intensity measurement with a Ge gamma detector all in the same apparatus, gives the On-Line Diffusion Chamber a unique ability to studies with short-lived radioisotopes or isomer states that are not possible in any other facility in the world.

Performance of ionization chambers in X radiation beams, radioprotection level

International Nuclear Information System (INIS)

Bessa, Ana C.M.; Potiens, Maria da Penha A.; Caldas, Linda V.E.

2005-01-01

Narrow beams, radioprotection level, were implanted in an X ray system, based on ISO 4037-1, as recommended by IAEA (SRS 16). Energy dependency tests were carried out and short-term stability in ionization chambers for use in radiation protection of trademark Physikalisch-Technische Werkstaetten (PTW), 32002 and 23361 models. The ionization chambers were studied with regard to short-term stability within the program of quality control of the laboratory, with a 90 Sr + 90 Y. The results of the short-term stability test were compared with the recommendations of IEC 60731, respect to dosemeters used in radiotherapy, since this standard presents the more restrictive limits with regard to the behaviour of ionization chambers. All cameras showed results within the limits recommended by this standard. With respect to the energy dependency of the response, the model Chamber 32002 presented a maximum dependence of only 2.7%, and the model Chamber 23361, 4.5%

α spectrometry grid ionization chamber: improvement of the characteristics

International Nuclear Information System (INIS)

Le Du, R.; Miltenberger, B.

1968-01-01

The rise time of the signals obtained with a grid ionization chamber depends on the orientation in the chamber and on the mobility of the ionization components. Our grid chambers are fitted with an electronic system which analyses the signals due to the electronic ionization components which are collected on the plate and on the source holder. By obtaining coincidence between these two signals, it is possible to select paths of any given orientation. Using this principle we have built an electronic collimator which does not have the disadvantages of a mechanical collimator for alpha spectra studies, and which, further, considerably reduces the background of the chamber. Simultaneously with the study of the improvement of a spectra with our device, we have been able to dissociate the contributions of back-diffusion and of self-absorption phenomena to the activity of an alpha source; some results will be presented. (authors) [fr

Investigation of thermal and temporal responses of ionization chambers in radiation dosimetry.

Science.gov (United States)

AlMasri, Hussein; Funyu, Akira; Kakinohana, Yasumasa; Murayama, Sadayuki

2012-07-01

The ionization chamber is a primary dosimeter that is used in radiation dosimetry. Generally, the ion chamber response requires temperature/pressure correction according to the ideal gas law. However, this correction does not consider the thermal volume effect of chambers. The temporal and thermal volume effects of various chambers (CC01, CC13, NACP parallel-plate, PTW) with different wall and electrode materials have been studied in a water phantom. Measurements were done after heating the water with a suitable heating system, and chambers were submerged for a sufficient time to allow for temperature equilibrium. Temporal results show that all chambers equilibrate quickly in water. The equilibration time was between 3 and 5 min for all chambers. Thermal results show that all chambers expanded in response to heating except for the PTW, which contracted. This might be explained by the differences in the volumes of all chambers and also by the difference in wall material composition of PTW from the other chambers. It was found that the smallest chamber, CC01, showed the greatest expansion. The magnitude of the expansion was ~1, 0.8, and 0.9% for CC01, CC13, and parallel-plate chambers, respectively, in the temperature range of 295-320 K. The magnitude of the detected contraction was <0.3% for PTW in the same temperature range. For absolute dosimetry, it is necessary to make corrections for the ion chamber response, especially for small ion chambers like the CC01. Otherwise, room and water phantom temperatures should remain within a close range.

The TJ-II data acquisition system: an overview

International Nuclear Information System (INIS)

Vega, J.; Cremy, C.; Sanchez, E.; Portas, A.

1999-01-01

The data acquisition system for the TJ-II fusion machine has been developed to coordinate actions among the several experimental systems devoted to data capture and storage: instrumentation mainframes (VXI, VME, CAMAC), control systems of diagnostics and a host-centralized database. Connectivity between these elements is achieved through local area networks, which ensure both good connections and system growth capability. Three hundred VXI based digitizer channels have been developed for TJ-II diagnostics. They are completely software programmable and provide signal analog conditioning. In addition, some of them supply a programmable DSP for real time signal processing. Data will be stored in a central server using a special compression technique that allows compaction rates of over 80%. A specific application software has been developed to provide user interface for digitizer programming, signal visualization and data processing during TJ-II discharges. The software is an event based application that can be remotely launched from any X terminal An authentication mechanism restricts access to authorised users only. (orig.)

Studies on the beam system for the calibration of the OPAL jet chamber with laser beams

International Nuclear Information System (INIS)

Maringer, G.

1988-07-01

UV laser beams are an important tool for the calibration of the OPAL jet chamber. A beam transport system containing about 350 mirrors in total guides the beams from the laser outside the detector into the chamber. Four of the mirrors are moveable under remote control allowing to guide the beams into each of the 24 sectors and to correct the beam path in case of deviations. A program to control these moveable mirrors has been developed. Drift velocity measurements will be performed by means of double beams which are generated by appropriate beamsplitters. Accurate knowledge of the double beam distances is essential to obtain the desired accuracy of better than 0.1% or 10 μm. Using a CCD device with a pixel size of 23x23 μm 2 the beam distance could be measured with errors below the required limit. (orig.)

Space-Ready Advanced Imaging System, Phase II