International Nuclear Information System (INIS)

A network of second-generation low-temperature gravitational radiation detectors is nearing completion. These detectors, sensitive to mechanical strains of order 10"-"1"8, are possible because of a variety of technical innovations that have been made in cryogenics, low-noise superconducting instrumentation, and vibration isolation techniques. Another five orders of magnitude improvement in energy sensitivity of resonant-mass detectors is possible before the linear amplifier quantum limit is encountered. 33 references, 3 figures, 1 table.

Energy Technology Data Exchange (ETDEWEB)

A simple arrangement of standard horizontal coaxial Ge(Li) detectors with the aim of constructing a Compton linear-polarimeter was tested. High polarization sensitivity and detection efficiency were achieved. The characteristics of the polarimeter and analysis of the observed quantities in terms of the linear-polarization mixing coefficient Hsub(l)(LL') are described.

CERN Document Server

We study an exactly solvable model where an uniformly accelerated detector is linearly coupled to a massless scalar field initially in the Minkowski vacuum. Using the exact correlation functions we show that as soon as the coupling is switched on one can see information flowing from the detector to the field and propagating with the radiation into null infinity. By expressing the reduced density matrix of the detector in terms of the two-point functions, we calculate the purity function in the detector and study the evolution of quantum entanglement between the detector and the field. Only in the ultraweak coupling regime could some degree of recoherence in the detector appear at late times, but never in full restoration, as an earlier work seems to suggest. We explicitly show that under the most general conditions the ...

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This document presents the current status of SiD's effort to develop an optimized design for an experiment at the International Linear Collider. It presents detailed discussions of each of SiD's various subsystems, an overview of the full GEANT4 description of SiD, the status of newly developed tracking and calorimeter reconstruction algorithms, studies of subsystem performance based on these tools, results of physics benchmarking analyses, an estimate of the cost of the detector, and an assessment of the detector R&D needed to provide the technical basis for an optimised SiD.

Energy Technology Data Exchange (ETDEWEB)

Realization of the scale of spectral responsivity of the detectors in the Directorate of Measures and Precious Metals (DMDM) is based on silicon detectors traceable to LNE-INM. In order to realize the unit of spectral irradiance in the laboratory for photometry and radiometry of the Bureau of Measures and Precious Metals, the new method based on the calibration of the spectroradiometer by comparison with standard detector has been established. The development of the method included realization of the System of Spectral Comparisons (SSC), together with the detector spectral responsivity calibrations by means of a primary spectrophotometric system. The linearity testing and stray light analysis were preformed to characterize the spectroradiometer. Measurement of aperture diameter and calibration of transimpedance amplifier were part of the overall experiment. In this paper, the ...

International Nuclear Information System (INIS)

This thesis reports on the fabrication and test of a new gaseous detector with a very large number of readout channels. This detector is intended for measuring the tracks of charged particles with an unprecedented sensitivity to single electrons of almost 100 %. It combines a metal grid for signal amplification called the Micromegas with a pixel readout chip as signal collecting anode and is dubbed GridPix. GridPix is a potential candidate for a sub-detector at a future electron linear collider (ILC) foreseen to work in parallel with the LHC around 2020--2030. The tracking capability of GridPix is best exploited if the Micromegas is integrated on the pixel chip. This integrated grid is called InGrid and is precisely fabricated by wafer post-processing. The various steps of the fabrication process and the measurements of its gain, energy resolution and ion back-flow property are reported in this ...

Energy Technology Data Exchange (ETDEWEB)

A detector has been developed and used to measure dose distributions versus linear energy transfer to thin gas targets in spherical geometry from fast neutron irradiation of tissue-equivalent plastic and carbon. The detector is a hemispherical proportional counter with a Cs(T1) scintillator at the center of the hemisphere. The coincidence of the proportional counter signals constrain the measurements to charged particles traversing the radius of the hemisphere. The charged particle energy deposition distributions are directly measured for a known pathlength. The A-150 kerma factor was measured at a neutron energy of 14.8 MeV and is in agreement with tabulated values. The carbon kerma factor measurements are less than the tabulated value at 14.8 MeV. The alpha-particle production in carbon was measured for neutron energies from 14.1 to 14.8 MeV and is compared with existing data.

Energy Technology Data Exchange (ETDEWEB)

Removing noise from data is often the first step in data analysis. Denoising techniques should not only reduce the noise, but do so without blurring or changing the location of the edges. Many approaches have been proposed to accomplish this; in this paper, they focus on one such approach, namely the use of non-linear diffusion operators. This approach has been studied extensively from a theoretical viewpoint ever since the 1987 work of Perona and Malik showed that non-linear filters outperformed the more traditional linear Canny edge detector. They complement this theoretical work by investigating the performance of several isotropic diffusion operators on test images from scientific domains. They explore the effects of various parameters such as the choice of diffusivity function, explicit and implicit methods for the discretization of the PDE, and approaches for the spatial discretization of the ...

Energy Technology Data Exchange (ETDEWEB)

In the food, chemical and safety industry there is a demand for gas detectors for process control applications, like quality control of food or leakage control in chemical plants. Gas sensor array systems have the potential to be used in this areas, with the advantage of being also affordable systems compared to other systems like gaschromatographs (GC) or infrared detectors (NIR, FTIR). One of the main drawbacks of the gas sensors is their response to non interesting ambient factors like temperature, pressure and humidity. Metal oxide sensors (MOS) have a low ambient temperature and pressure dependency. Some of them (SnO + dopands) have some sensitivity to humidity. In many cases the response of the sensors is often non-linear, which implies a concentration dependant pattern of the samples. (orig.)

Energy Technology Data Exchange (ETDEWEB)

During this reporting period the work supported by the US Department of Energy Grant No. DE-FG02-87ER40326.A005 has resulted in two publications and two papers presented at professional meetings. The neutron scattering measurement for this budget period has been completed along with scattering measurements for carbon {sup 88}Sr, {sup 40}Ar, {sup 90}Zr, {sup 208}Pb, {sup 40}Ca and {sup 28}Si. The carbon scattering yield serves to define the detector efficiencies. The silicon sample was available and is of importance in both nuclear physics and reactor physics.

International Nuclear Information System (INIS)

Nuclear radiation detectors in integral execution were produced by successive epitaxial growth from vapor phase of Zn Te and Cd Se thin layers onto scintillating Zn Se (Te) crystals. The irradiation of combined Zn Se (Te) - Zn Te - Cd Se detectors by Cu_K_a X-rays leads to the appearance of photoreceiver e.m.f., which tends to saturation with the increase of X-ray radiation dose reaching the value of 0.34-0.40 V at 200 R/min. The short circuit current dependence of irradiation dose power is linear. The matching factor for detectors with Zn Te-Cd Se photoreceivers with different doping levels is 0.68-0.92. The absolute monochromatic sensitivity is 0.32-0.35 m A/m W at a quantum efficiency 0.58-0.61 and a time constant 2 x 10"-"4 s. The calculated dose sensitivity for Zn Se(Te)-Zn Te-Cd Se combined detectors at the irradiation with X-rays having effective energy 8.86 keV gives the ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

The reactor core of TAPP-3 and 4 is divided into 14 power zones for spatial power control. Corresponding to each zone is a light water zonal compartment. The 14 ZCCs are located in two radial planes, each containing 7 ZCCs. For each zone, power measurement is carried out using three cobalt Self Powered Neutron Detectors (SPNDs) at appropriate locations close to the respective ZCC. Since the zone power as obtained by the true average of the healthy zone control detector (ZCD) readings belonging to a particular zone may not correspond to its actual power because these 3 detectors per zone, measure only point fluxes but the zone extends over a large core region. Therefore accurate estimation of zone power calibration factors is required to estimate the zone powers and also to provide effective spatial power control to avoid the xenon induced spatial power oscillations in large PHWRs like 540 MWe Reactor. This accurate ...

International Nuclear Information System (INIS)

A heavy ion gas detector system consisting of a Bragg-curve spectroscopy ionization chamber for particle identification and a multiwire proportional chamber as position sensitive fast trigger device is described. The Bragg IC has been tested with several beams up to Z=36 to investigate some aspects of the BCS method. Results are reported on energy resolution and linearity, Z resolving power and mass sensitivity. The energy resolution is well below 1%. The Bragg-peak amplitude is fairly independent of the energy in a wide energy range and single elements are identified up to Z=38 with a resolving power Z/#DELTA#Zproportional50-80. Isotope identification by range measurement is limited by the straggling in the ionization process and the mass resolving power is M/#DELTA#Mproportional20-26 for S and Si isotopes. The MWPC allows subnanosecond time resolution and position identification along the in-plane coordinate within +-0.5 mm. (orig.).

CERN Document Server

CZT Detector and HXI Development at CASS/UCSD

International Nuclear Information System (INIS)

We describe a position sensitive photon counting microchannel plate based detector with an improved quadrant anode (QA) readout system. The technique relies on a combination of the four planar elements pattern and an additional fifth electrode. The charge cloud induced by single particle detection is split between the electrodes. The measured charge values uniquely define the position of the initial event. QA has been first published in 1976 by Lampton and Malina. This anode configuration was undeservedly forgotten and its potential has been hardly underestimated. The presented approach extends the operating spatial range to the whole sensitive area of the microchannel plate surface and demonstrates good linearity over the field of view. Therefore, the novel image sensor results in spatial resolution better then 50?m and count rates up to one million events per second.

Energy Technology Data Exchange (ETDEWEB)

During this reporting period the work supported by the US Department of Energy Grant No. DE-FG02-87ER40326.A005 has resulted in two publications and two papers presented at professional meetings. The neutron scattering measurement for this budget period has been completed along with scattering measurements for carbon {sup 88}Sr, {sup 40}Ar, {sup 90}Zr, {sup 208}Pb, {sup 40}Ca and {sup 28}Si. The carbon scattering yield serves to define the detector efficiencies. The silicon sample was available and is of importance in both nuclear physics and reactor physics.

International Nuclear Information System (INIS)

The radionuclide X-ray fluorescence analyzer consists of a source changer and a sample changer. "5"5Fe, "1"0"9Cd and "2"4"1Am are used as excitation sources. The radiation is detected with a semiconductor Si(Li) detector. The complete assembly of the apparatus consists of an imagine unit, a keyboard, a floppy disc drive, a printer, a console and a rack with analog and digital electronics. Its multichannel amplitude analyzer consists of power supplies, a high voltage supply, a linear amplifier, an analog-to-digital converter and a computer. The technical specifications are given. The control and data processing system is controlled with an MHB 8080A microprocessor. Software for semiconductor gamma spectrometry and for quantitative gamma spectrometry will be supplied with the equipment. (E.S.). 3 figs., 4 refs.

International Nuclear Information System (INIS)

In this work, the half-life of the "1"5"5Sm #beta#"- decay was determined using enriched "1"5"4Sm samples submitted to irradiation in the IEA-R1 reactor of IPEN; the activity of the samples were followed for 4-5 consecutive half lives using a 198 cm"3 HPGe detector. The data was corrected using a non paralizable dead time correction and fitted to an exponential decay function using a non linear fitting procedure developed on the MatLab platform. The resulting value--T_1_/_2 = 22.180(26) min--was compatible to the one found in the literature, with a lower uncertainty.

Energy Technology Data Exchange (ETDEWEB)

In the last 30 years high energy physics could write an impressive story of success. Since the introduction of the Standard Model (SM), it has met every experimental test. However the final confirmation has to prove the mechanism of electroweak symmetry breaking, which could not be confirmed yet. The most favored theory, which includes the introduction of a Higgs field, could not be verified experimentally. Furthermore there is clear evidence, that the SM is only a low energy description of nature and its principles, as the SM describes only 4 % of the known matter in the universe. There are two different approaches in accelerator driven high energy physics to clarify the open questions. The Large Hadron Collider (LHC) have a good opportunity to measure some of the missing pieces with its high center of mass energy. The International Linear Collider (ILC) will then measure their parameters with high precision. To guarantee this high precision the ...

J-STORE (Japan)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

CERN Multimedia

Small world when building a particle detector prototype, the devil is in the tiny details

Science.gov (United States)

Using static Michelson interferometer to get the spectrum information of measurement targets for spectrum identification, under the condition that the interference length is constant, the system can be optimized by BP neural network algorithm for the mixed spectral separation process. Thereby it can realize improving the recognition probability of camouflage target. Collecting the spectrum information in field of view (FOV) by the interferometer and linear array CCD detector, composing the set of mixed spectrum data, with known absorption spectrum of the material as a hidden layer of rules, it used BP neural network to separate the mixed spectrum data. Experiment with different distances, different combinations of mixed background spectrum as the initial data, using steel target (size: 1.5 m x 1.5 m) made of four kinds, the recognition probability of non-camouflage target is about 90% by BP neural network algorithm or the traditional algorithm, ...

British Library Electronic Table of Contents (United Kingdom)

The L shell fluorescence cross-sections of the elements in range 45Z50 have been determined at 8keV using Synchrotron radiation. The individual L X-ray photons, Ll, La, LbI, LbII, LgI and LgII produced in the target were measured with high resolution Si(Li) detector. The experimental set-up provided a low background by using linearly polarized monoenergetic photon beam, improving the signal-to-noise ratio. The experimental cross-sections obtained in this work were compared with available experimental data from Scofield [1,2] Krause [3,4] and Scofield and Puri et al. [5,6]. These experimental values closely agree with the theoretical values calculated using Scofield and Krause data, except for the case of Lg, where values measured of this work are slighter higher.

CERN Document Server

This paper focuses on the cross-layer issue of joint multiuser detection and resource allocation for energy efficiency in wireless CDMA networks. In particular, assuming that a linear multiuser detector is adopted in the uplink receiver, the case considered is that in which each terminal is allowed to vary its transmit power, spreading code, and uplink receiver in order to maximize its own utility, which is defined as the ratio of data throughput to transmit power. Resorting to a game-theoretic formulation, a non-cooperative game for utility maximization is formulated, and it is proved that a unique Nash equilibrium exists, which, under certain conditions, is also Pareto-optimal. Theoretical results concerning the relationship between the problems of SINR maximization and MSE minimization are given, and, resorting to the tools of large system analysis, a new distributed power control algorithm is implemented, based on very little prior ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes Fuji computed radiography (FCR) of Fuji Film for NDT (non-destructive testing). Imaging plate (IP) is a two-dimensional detector of X-ray, and shows higher photographic sensitivity than X-ray film. The output emission of IP provides a good linear relationship to X-ray intensity in a wide intensity range. When this emission can be digitized, the X-ray intensity can be also digitized. IP is applied to NDT as an inspection using X-ray. FCR provides higher photographic sensitivity than the conventional X-ray film method, which results in one-fifth to one-twentieth of irradiation time. Images with stable density can be obtained independent of the intensity. Since IP has a wide dynamic range, the variation of X-ray intensity of 1:500 can be expressed in a single image by single shot. High density record including 1000 images can be done using a 5.25 inch optical disk through the digital image processing and the electrical ...

Science.gov (United States)

The x-ray diffraction technique described previously for measurement of growth kinetics of Pd/sub 2/Si layers from their solid state reaction couples has been extended by the use of a one-dimensional position-sensitive detector (PSD). Additionally, the method has been extended to include measurement of the Pd layer. A detailed description of the experimental arrangement and analytical procedures is presented. The kinetics of epitaxial Pd/sub 2/Si film growth were measured in situ over a range of 170--230 /sup 0/C. The PSD results, using data obtained from both the Pd/sub 2/Si and Pd layers, were able to confirm parabolic growth behavior for the Pd/sub 2/Si film. The rate constants followed Arrhenius behavior and yielded an activation energy of E = 1.32 +- 0.07 eV with a prefactor k/sub 0/ = 0.49 cm/sup 2//s for the Pd/sub 2/Si layer analysis and E = 1.34 +- 0.17 eV with a prefactor of 0.72 cm/sup 2//s for the Pd layer analysis. The PSD technique significantly ...

Energy Technology Data Exchange (ETDEWEB)

The physics and technology of this new Cerenkov detector are discussed, including materials studies, construction techniques, and resolution measurements. Sources of resolution error are individually identified and measured where possible. The results of all studied indicate that the measurement resolution is understood. This work has led to the adoption of a large scale ring imaging detector as part of a new high energy physics spectrometer, the SLD, at the Stanford Linear Accelerator Center. Results from an amplitude analysis of strange meson final states in K/sup /minus//p ..-->.. /ovr K/sub 0//..pi../sup /minus//p interactions are presented. The data derive from a 4 event/nb exposure of the LASS (large Aperture Superconducting Solenoid) spectrometer to an 11 GeV/c K/sup /minus// beam. The data sample consists of /approximately/100,000 vents distributed over the Dalitz plot of the channel. The process is observed to ...

International Nuclear Information System (INIS)

For the first time a segmented n-type HPGe detector was operated directly submerged in liquid nitrogen over a long period. As this kind of detector is envisioned to be used in GERDA phase II, it was operated with a low mass signal cable with snap-contacts and mounted in a low-mass copper holder. The detector performance was stable over 146 days, indicating that neither detector nor contacts deteriorated.

Energy Technology Data Exchange (ETDEWEB)

Abstract not provided

Science.gov (United States)

Spline functions associated with a general linear differential operator L which interpolate prescribed data with respect to arbitrary linear functionals are investigated. (Author)

Energy Technology Data Exchange (ETDEWEB)

A prototype detector based on the inclined absorber layer principle is introduced. For the Liquids Reflectometer at the Spallation Neutron Source, it is shown to be a significant improvement over its current detector, which imposes an instantaneous count rate limitation of 50 kcps.

International Nuclear Information System (INIS)

The design and first results from a Double Sided Silicon Strip Detector (DSSSD) recently installed at the Lund Nuclear Microprobe facility (NMP) are presented. The detector has 64 sector strips and 32 ring strips, which in combination give more than 2000 detector cells, each with characteristics comparable with a standard surface barrier detector (SBD). The detector has been tested both with radioactive sources and with different ion beams and energies. The most striking features are the high rate virtually pile-up free operation and also the possibility of detailed measurement of angular distributions.

Science.gov (United States)

... The approach is to perform noise spectral density measurements and selected materials structure measurements on GaAs detector materials, with ...

CERN Document Server

A highly integrated trigger and readout system for a silicon micro-strip detector installed at the CERN Omega spectrometer

International Nuclear Information System (INIS)

The detection efficiency of a lithium glass detector was calculated using MCNP code, and the calculation was compared with the published results in Pulsed Sphere Plan. A lithium glass detector of our own was made, and its neutron efficiency was calculated. The calculated neutron efficiency was verified with both pulsed and steady DD neutrons. Characteristics of Neutron response of "6Li detector was discussed. (authors)

International Nuclear Information System (INIS)

Short communication.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

CERN Document Server

The internal-tracking-system (ITS) of the ALICE detector at LHC, consists of six concentrical barrels of silicon detectors. The outmost two layers are made of double-sided strip detectors (SSD). In the framework of a R and D, the characteristics and performances of these devices, manufactured by two different companies, associated with their designed read-out electronics, have been studied off- and in-beam at the SPS (CERN). The results are presented and discussed.

Science.gov (United States)

radionuclide X-ray fluorescence analysis: the resolving power of the ... The radiation detectors used in radionuclide X-ray fluorescence ...

Science.gov (United States)

Counting characteristics of X-ray detectors fabricated from indium-doped, gallium-doped, and chlorine-doped CdTe have been investigated. The detectors fabricated from indium-doped and gallium-doped crystals showed radiation-induced polarization, namely, a progressive decrease of count rate with an increase of photon fluence in the high-photon-fluence region, while the detectors fabricated from chlorine-doped crystals did not. Results from current-voltage characteristics of the detectors indicated that the different counting characteristics of these detectors originated from the difference in internal electric fields in each detector.

Energy Technology Data Exchange (ETDEWEB)

In this paper, the design of large thin PIN detector with a membrane stress avoidance configuration is proposed, and the related device fabrication process is developed. Ultra-thin PIN detector {approx} 1.13 cm{sup 2} in area is fabricated on a thin ( {approx} 35{mu}m) silicon membrane, and characterized. Detector performance improvement has been successfully demonstrated. With the membrane stress avoidance design, the improved detector exhibits a leakage of 6nA, which is at least 5 times lower than that of detector of identical junction area. The new detector features a full depleted capacitance of 110 pF, and a FWHM of 40.86 keV energy resolution for 5.486 MeV alpha particle spectrography.

International Nuclear Information System (INIS)

High (spatial) resolution imaging detectors for X-ray astronomy were developed. Several prototype detectors built and their feasibility and baseline performance were assessed. Two of these detector types are proposed for investigations on the advanced X-ray astrophysics facility (AXAF). The readiness of a new X-ray imaging system, the charge coupled device (CCD) imaging specctrometer is outlined, and state of the art performance parameters for microchannel plate (MCP) and CCD detectors are measured. Laboratory facilities and procedures for coating MCP are developed general high resolution imagery systems are analyzed.

Energy Technology Data Exchange (ETDEWEB)

The paper outlines the basic problems concerning creation of electron-positron linear colliders, as well as their present-day status. More details on the question can be found in the proceedings of recent workshops on linear colliders contained in the References. ((orig.)).

Science.gov (United States)

The technology for flue gas desulfurization (FGD) with seawater is widely adopted by coal-fired power plants in coastal areas. SO2 in the flue gas is absorbed by alkaline seawater and transfered in aqueous phase as sulfite (SO3(2-)), and most SO3(2-) is transformed to sulfate (SO4(2-)) after an aeration process. The remaining SO3(2-) in the seawater discharged to sea area may be harmful to marine organism because of its biological toxicity, thus it is necessary to determine the concentration of SO3(2-) in the seawater for desulfurization. In this study, the method of determination of SO3(2-) in the seawater by ion chromatography was investigated. The separation was achieved on an IonPac AS14A column with 14 mmol/L NaOH-12 mmol/L Na2 CO3 solution as the mobile phase at a flow rate of 1.2 mL/min, and the detection was performed by a pulsed amperometric detector. Formaldehyde was added as a protective agent when sampling because the SO3(2-) is easy to be oxidized. To ...

Energy Technology Data Exchange (ETDEWEB)

Personnel radiation monitoring is essential to the operation of any nuclear facility and work in this area continues to strive for an accurate determination of personnel dose. In particular recent attention has been focused upon the need to improve the accuracy of neutron dosimetry, mainly because of their high Relative Biological Effectiveness. In this work the feasibility of using the NE-213 liquid scintillation detector as an efficient neutron/..gamma.. ray radiation monitor is demonstrated. Derivative method spectrum unfolding used in MATXUF for on-line analysis of fast neutron spectra has also been applied to real time ..gamma.. spectrum unfolding (MATXUF2), making possible simultaneous on-line monitoring of both fast neutrons and gammas. To eliminate the negative fluxes in the unfolded ..gamma.. spectra created by the photopeak-Compton edge combination in the plateau portion of the knee response, correcting equations using a linearized ...

Science.gov (United States)

Personnel radiation monitoring is essential to the operation of any nuclear facility and work in this area continues to strive for an accurate determination of personnel dose. In particular recent attention has been focused upon the need to improve the accuracy of neutron dosimetry, mainly because of their high Relative Biological Effectiveness. In this work the feasibility of using the NE-213 liquid scintillation detector as an efficient neutron/gamma ray radiation monitor is demonstrated. Derivative method spectrum unfolding used in MATXUF for on-line analysis of fast neutron spectra has also been applied to real time gamma spectrum unfolding (MATXUF2), making possible simultaneous on-line monitoring of both fast neutrons and gammas. To eliminate the negative fluxes in the unfolded gamma spectra created by the photopeak-compton edge combination in the plateau portion of the knee response, correcting equations using a linearized approximation ...

Science.gov (United States)

Geometra'. Scrape Geom- ett_,. Used By: Theoretical. FEM Weight. Apply Linear Delta ...... that the FEM is geometri- cally linear, the differences between ...

International Nuclear Information System (INIS)

... electron guns linear accelerators magnetrons multivibrators pulse generators

UK PubMed Central (United Kingdom)

An ultrasensitive laser-induced fluorescence detector was used with capillary electrophoresis for the study of 5-carboxy-tetramethylrhodamine. The raw signal from the detector provided roughly...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The most important developments in gaseous detectors at LNL are reviewed. Some aspects of timing, pulse height and position resolutions of avalanche counters are reported. The experimental work on heavy-ion identification by Bragg curve spectroscopy is summarized.

Energy Technology Data Exchange (ETDEWEB)

Detectors for a photon-photon collider are envisaged using as guide-lines the physics goals and the interaction point environment. Production of SUSY Higgs scalar and pseudo-scalar is emphasized. Some aspects of the interaction point environment are discussed. ((orig.)).

KoreaScience (Korea)

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KoreaScience (Korea)

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Science.gov (United States)

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International Nuclear Information System (INIS)

(Jun 1978). United States Miller, H. Univ. of Missouri, Columbia Peterman,

International Nuclear Information System (INIS)

Czech May 1979. p. 32-33. Czechoslovakia Benada, J. Spacek, B. Ustav

Energy Technology Data Exchange (ETDEWEB)

A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.

Energy Technology Data Exchange (ETDEWEB)

A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.

CERN Document Server

In this paper we describe the reconstruction strategies, the calibration procedures and the detector performance results from the latest CMS operation.

Energy Technology Data Exchange (ETDEWEB)

A new technique for radon measurement in the natural environment was investigated. It is based on the use of activated charcoal and a track-etch detector. The charcoal acts as a radon collector from the air and the track-etch detector as a recorder of the alpha particles emitted by radon and its decay products. Our preliminary results show that the response of the new dosimeter to radon, using Deodorant activated charcoal (TOK, Yugoslavia) and a CR-39 track-etch detector, is 1.4 tracks cm{sup -2}/Bqm{sup -3}d, which is about eight times higher than that obtained with a standard track-etch dosimeter. (author).

Energy Technology Data Exchange (ETDEWEB)

Presented are results of a test of a method for measuring neutron fluences using detectors with fissionable nuclides. The investigations show the soundness of of using neutron-activation detectors of the type Am for mesurements in nuclear installations for values of thermal-neutron fluence of from 10/sup 13/ to 10/sup 20/ neutrons/cm/sup 2/ with exposure for up to several months. The proposed method can be used for prolonged measurements in strong fields of both thermal and fast neutrons.

Energy Technology Data Exchange (ETDEWEB)

The design of beam position monitor (BPM) stripline detectors has been enhanced by using the finite element code ANSYS[sup TM]. Available from Swanson Engineering, ANSYS[sup TM] was developed to solve Poisson's equation in stress and thermal analysis applications. The code is readily adaptable to solving electrostatic problems. The designs of several beam detectors were iterated by calculating electrode capacitances and characteristic impedances to better than 1% accuracy.

Energy Technology Data Exchange (ETDEWEB)

The neutron detector is cased in a metal envelop and has one detector with a very sensitive fission chamber and a second detector with a fission chamber less sensitive that the first one and a boron coated ionisation chamber for reducing gamma radiation detection.

Science.gov (United States)

Ionization counters employing Bragg curve spectroscopy have been constructed for use in a 4? geometry. These detectors compare very favorably in terms of both energy and charge resolution with small solid angle devices. These detectors have a large dynamic range because they are backed by scintillation detectors, and are thus capable of detecting and identifying particles with energies from 1 MeV/nucleon up to 200 MeV/nucleon.

International Nuclear Information System (INIS)

Ionization counters employing Bragg curve spectroscopy have been constructed for use in a 4#pi# geometry. These detectors compare very favorably in terms of both energy and charge resolution with small solid angle devices. These detectors have a large dynamic range because they are backed by scintillation detectors, and are thus capable of detecting and identifying particles with energies from 1 MeV/nucleon up to 200 MeV/nucleon. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Waveform correlation detectors compare a signal template with successive windows of a continuous data stream and report a detection when the correlation coefficient, or some comparable detection statistic, exceeds a specified threshold. Since correlation detectors exploit the fine structure of the full waveform, they are exquisitely sensitive when compared to power (STA/LTA) detectors. The drawback of correlation detectors is that they require complete knowledge of the signal to be detected, which limits such methods to instances of seismicity in which a very similar signal has already been observed by every station used. Such instances include earthquake swarms, aftershock sequences, repeating industrial seismicity, and many other forms of controlled explosions. The reduction in the detection threshold is even greater when the techniques are applied to arrays since stacking can be performed on the ...

International Nuclear Information System (INIS)

TAPP-3 and 4 reactors use large number of Self Powered Neutron Detectors (SPNDs) for Neutronic lower measurement and control. To perform in-situ calibration of these detectors in select locations and to validate the reactor physics codes which predict flux at various points in the core, traveling in-core probes (TIP) are required. The TIP assembly consists of a miniature neutron sensitive detector. The detector is driven in and out of core using a mechanism which facilitates positioning of the detector anywhere inside a vertical tube (Central carrier tube of any of the six select Vertical Flux Units) in the core. TIP is driven through retractable feed mechanism for a stroke of 13 m. This paper describes the developmental efforts and the operational feedback of the retractable feed mechanism for the stroke of 13 m used at TAPP 3 and 4 reactor. (author)

International Nuclear Information System (INIS)

Solid state nuclear track detectors (SSNTD) are widely used for radon measurements and CR-39 is one of the most popular SSNTD. In this work it was determined the calibration factor for radon concentration measurements through the passive method with CR-39 detectors. The detectors were put in a proper device (an adapted Lucas cell) and exposed to the standard radon concentration through the Pylon Model RN-150 flow through radon gas source. After exposure, the detectors were etched for 5.5 hours in a KOH solution at 80 deg C in a bath at a constant temperature. The track density was read in an Axiolab-Zeiss optical microscope, with nominal magnification of X10 connected to a video camera and to a personal computer. The calibration factor was obtained through the relation between standard radon concentration, track density and exposure time. (author)

Energy Technology Data Exchange (ETDEWEB)

A large area Bragg curve spectroscopy (BCS) detector and a position sensitive parallel grid avalanche counter have been developed to study heavy ion reactions, such as inelastic excitations and few nucleon transfer reactions near the Coulomb barrier. Reasonably good resolutions have been achieved for energy, atomic number and angle. A theoretical investigation on the mass dependence of the Bragg peak signal from the BCS detector, shows that there is a negligible mass dependence related to the geometry of the detector. The mass number of the heavy ions which cannot be obtained by the above method, has been identified by detecting the corresponding characteristic gamma rays from the product nuclei with two large solid angle gamma ray detectors. (orig.)

Energy Technology Data Exchange (ETDEWEB)

A large acceptance, high stopping power, Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. The detector design was aided by the results of computer simulations of the electron collection process in the detector, and of the signal processing in the electronics. The signals from the Bragg curve spectrometer are recorded in a waveform digitizer and the Bragg peak height, range, position and pileup rejection information are determined from software analysis of the recorded signals. Factors limiting the performance of the detector are discussed, and results obtained with ...

British Library Electronic Table of Contents (United Kingdom)

An evaporative cooling system developed for operation and qualification testing of silicon pixel and microstrip detectors for the inner tracking detector of the CERN ATLAS spectrometer is described. Silicon detector substrates must be continuously operated between 0 and ???7?C in the high radiation environment near the circulating beams at the CERN Large Hadron Collider (LHC). This requirement imposes unusual constraints on the cooling system and has led to the choice of perfluoro-n-propane (C3F8) refrigerant, which combines good chemical stability under ionizing radiation with high dielectric strength and nonflammability. Since the silicon detectors must also be of extremely light construction to minimize undesirable physics background, coolant tubes are of thin (200 ?m) aluminum wall, wh...

Energy Technology Data Exchange (ETDEWEB)

This report compares the performance characteristics of /sup 10/B-lined and fission-neutron detectors in gamma-ray fluxes typical of the fields to be encountered during nondestructive testing of irradiated light-water fuel assemblies stored in water. Using the optimum time constants for each of the /sup 10/B-lined detectors, the 0.25-in.-dia detector had a 5% loss in neutron count sensitivity at 7000 rad/h. Similarly, the 0.5-in.-dia detector had a 7% loss at 13,000 rad/h and the 1-in.-dia detector had a 5% loss in sensitivity at 1000 rad/h. Uranium-235 fission chambers were operated successfully in fields above 100,000 rad/h with no loss in neutron counting sensitivity. Shielding calculations were done to determine the appropriate shield thickness needed for a /sup 10/B-lined neutron detector to operate in a 50,000 rad/h field, typical of light-water-reactor ...

CERN Document Server

This dissertation describes the evaluation of many-pixel Cadmium-Zinc-Telluride (CdZnTe) hard-X-ray detectors for future use with the High Energy Replicated Optics (HERO) telescope being developed at Marshall Space Flight Center. The detector requirements for the HERO application are good energy resolution (sufficient to resolve cyclotron features and nuclear lines), spatial resolution of ∼200 μm, minimal charge loss of absorbed X rays, and minimal sensitivity to the background environment. This research concentrates on assessing the suitability of these detectors for the focus of HERO, and includes the development of a simulation of the physics involved in an X-ray-detector interaction, a study of the intrinsic material properties, measurements with prototype detectors such as the energy and spatial resolution, charge loss, and X-ray background reduction through ...

UK PubMed Central (United Kingdom)

Strong inhibitory effects of the anionic surfactant linear alkylbenzene sulfonate (LAS) on four strains of autotrophic ammonia-oxidizing bacteria (AOB) are reported. Two Nitrosospira...Full Text Available

UK PubMed Central (United Kingdom)

SummaryWe develop a new class of models, dynamic conditionally linear mixed models, for longitudinal data by decomposing the within-subject covariance matrix using a special Cholesky...Full Text Available

UK PubMed Central (United Kingdom)

The realization theory linear dynamical systems, previously developed over a field, are extended to a large class of commutative rings. The principal result is that the existence criterion for a finite...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A general model for wakefield-generated instabilities in linear accelerators, originally developed for cumulative beam breakup [1], is applied to the resistive wall instability. The general solution for various bunch charge distributions and application to various accelerator configurations are presented.

Science.gov (United States)

... Effect of checkpointing and queueing on program performance ... and a large class of stochastic linear ... problem is intrinsically related to K-terminal ...

International Nuclear Information System (INIS)

The control valve for a large steam turbine must be operated linearly to be run by an automatic control system in a power plant. It is, however, found that the flow increase is much greater for a given valve position change near the closed end of travel than it is near the open end. Accordingly, the desired linearization will be achieved if the valve is opened less near the closed end of travel and greater near the open end. The previous way for linearization was to utilize the cams, which is called the mechanical hydraulic control (MHC). The MHC was afterward improved by producing the nonlinear electric compensation to the nonlinear system of control valves, viz. the electro hydraulic control (EHC)

Science.gov (United States)

... The ultimate compressive strength was measured, and values for Young's modulus were calculated from the linear portion of the test curve. ...

Energy Technology Data Exchange (ETDEWEB)

Non-linear autoregressive Markov regime-switching models are intuitive. Time-series approaches for the modelling of electricity spot prices are frequently proposed. In this paper, such models are compared with an ordinary linear autoregressive model with regard to their forecast performances. The study is carried out using German daily spot-prices from the European Energy Exchange in Leipzig. Four non-linear models are used for the forecast study. The results of the study suggest that Markov regime-switching models provide better forecasts than linear models. (author)

Science.gov (United States)

... Both effects are undoubtedly caused by the ahaping of the spool valve flow characteristics The linear region of response corresponds to ...

Energy Technology Data Exchange (ETDEWEB)

The detector for retrospective radon exposure measurements is developed. The detector consists of the multilayer package of solid-state nuclear track detectors LR-115 type. Nitrocellulose films works both as {alpha}-particle detector and as absorber decreasing the energy of {alpha}-particles. The uncertainties of implanted {sup 210}Pb measurements by two- and three-layer detectors are assessed in dependence on surface {sup 210}Po activity and gross background activity of the glass. The generalized compartment behavior model of radon decay products in the room atmosphere was developed and verified. It is shown that the most influencing parameters on the value of conversion coefficient from {sup 210}Po surface activity to average radon concentration are aerosol particles concentration, deposition velocity of unattached {sup 218}Po and air exchange rate. It is demonstrated that with ...

Energy Technology Data Exchange (ETDEWEB)

The {sup 252}Cf-source-driven noise analysis method is a versatile measurements tool that has been applied to measurements for initial loading of reactors, quality assurance of reactor fuel elements, fuel processing facilities, fuel reprocessing facilities, fuel storage facilities, zero-power testing of reactors, verification of calculational methods, process monitoring, characterization of storage vaults, and nuclear weapons identification. This method`s broad range of application is due to the wide variety of time- and frequency domain signatures, each with unique properties, obtained from the measurement. The following parameters are obtained from this measurement: average detector count rates, detector multiplicities, detector autocorrelations, cross-correlation between detectors, detector autopower spectral densities, cross-power spectral densities between ...

International Nuclear Information System (INIS)

Neutron semiconductor detectors for neutron counting and neutron radiography have an increasing importance. Simple silicon neutron detectors are combination of a planar diode with a layer of an appropriate neutron converter such as 6LiF. These devices have limited detection efficiency of not more than 5%. The detection efficiency can be increased by creating a 3D microstructure of dips, trenches or pores in the detector and filling it with a neutron converter. The first results related to the development of such devices are presented. Silicon detectors were fabricated with pyramidal dips on the surface covered with 6LiF and then irradiated by thermal neutrons. Pulse height spectra of the energy deposited in the sensitive volume were compared with simulations. The detection efficiency of these devices was about 6.3%. Samples with different column sizes were fabricated to study the electrical properties ...

Science.gov (United States)

In this communication we propose a method to implement an all-optical astable multivibrator using the non-linear material based switches and logic gates. The scheme can operate in real time. The delay time can achieve ps(pico-second). The pulse duration can be made very low and may cross the THz easily by selecting proper material and laser source.

International Nuclear Information System (INIS)

The cross-coupled interferometer is a new design for interferometric gravitational wave detectors. Similar to the baseline gravitational wave detectors proposed for Advanced LIGO, it uses long-arm cavities in which the signal is generated. The signal fields are then extracted from the arm cavities with an additional cavity behind the long-arm cavities. The tuning of this signal extraction cavity and the parallel tuning of the signal recycling mirror can be used to optimize the peak frequency and the bandwidth of the detector independently. If we replace the signal recycling mirror by a small cavity, it is possible to amplify signals in two different frequency bands.

International Nuclear Information System (INIS)

The proposed Sudbury Neutrino Observatory is based on a Cherenkov detector which has a total of 1000 tonne of heavy water and 1800 tonne of light water for its sensitive volume. The detector is optimized for the measurement of extra-terrestrial low energy electron neutrinos and electron antineutrinos spectra as well as the total neutrino flux independent of neutrino flavours. It will delineate the Standard Solar Model and neutrino propagation aspects of the solar neutrino problem, provide detailed information on the dynamics of stellar collapse and measure neutrino masses and oscillation parameters with high sensitivity.

International Nuclear Information System (INIS)

A method and apparatus for nuclear borehole logging, and in particular, neutron porosity logging, uses a neutron source, and a pair of spaced lithium detectors, preferably Li"6I crystal or Li"6 doped glass, to detect neutrons emitted from a borehole formation being logged. The spectrum developed by the lithium detectors is processed to remove the gamma ray background radiation and the hydrogen absorption peak, thus allowing a more accurate neutron count. A Gaussian curve is fitted to the neutron peak of the spectrum, the curve eliminating the hydrogen absorption peak. The area under this Gaussian curve represents the neutron count. (author).

Energy Technology Data Exchange (ETDEWEB)

A large acceptance, high stopping power Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. Factors affecting the performance of the detector are discussed, and results obtained with the detector are presented. (orig.).

Science.gov (United States)

Recent rapid growth in mobile computing technologies enables telemedicine applications to operate on mobile devices. Our focus is on the design of an integrated electrocardiogram (ECG) beat detector on a Personal Digital Assistant (PDA) platform for the health screening process. The ECG beat detector module will be supported by the PDA version of Personal Health Information Management System (PHIMS) and Facilitated Accurate Referral Management System (FARMS) through wireless network infrastructure as a home-based mobile cardiac monitoring solution. PMID:17282192

International Nuclear Information System (INIS)

The Bragg-curve detector of the parallel plate ionization chamber type generates a signal that is a distorted replica of the original Bragg-curve. In result of this distortion, the signal peak height is not only a function of the atomic number of the heavy ion, as it is often stated, but also of the particle mass. This mass effect was studied with the aid of computer simulation, and it was found to be dependent on the Frisch grid to anode gap width and on the detector gas. The charge resolution of the detector is affected very significantly by this mass dependence of the signal peak height. Therefore, a careful selection of the detector gas and the grid to anode gap width is necessary, if good charge resolution over a wide range of heavy ions is required. (orig.).

Energy Technology Data Exchange (ETDEWEB)

A Bragg curve detector (BCD) has been designed and built to be used for AMS purposes. Its design is described and its performance, obtained in tests at the Australian National University (ANU), is reported. At a {sup 36}Cl energy of 154 MeV, the energy resolution was found to be 0.38%, and the charge resolution 1.3%. The {sup 36}Cl and {sup 36}S are completely discriminated. Good separation was also achieved at 64 MeV, and a measurement at this energy of the {sup 36}Cl/Cl ratio of a sample measured previously at 154 MeV with the standard ANU ionization detector agreed well with the earlier value. This very simple detector has been shown to be suitable for use in AMS programs.

CERN Document Server

The development of a replacement to the conventional film based X-ray imaging technique is required for many reasons. One possible route for this is the use of a large area film of a suitable semiconductor overlaid on an amorphous silicon readout array. A suitable semiconductor exists in cadmium telluride and its tertiary alloy cadmium zinc telluride. In this thesis the spectroscopic characteristics of commercially available CZT X- and gamma-radiation detectors are established. The electronic, optical, electro-optic, structural and compositional properties of these detectors are then investigated. The attained data is used to infer a greater understanding for the carrier transport in a CZT radiation detector following the interaction of a high energy photon. Following this a method used to fabricate large area films of CdTe on a commercial scale is described. This is cathodic electrodeposition from an aqueous electrolyte. ...

International Nuclear Information System (INIS)

The properties of individual radioactive particles present in a sample, such as a swipe, are more interesting than bulk properties of the sample. The present work focuses on instrumentation that provides position-sensitive spectral information non-destructively from the sample. The experimental part of the work was realized using a device called PANDA (Particles And Non-Destructive Analysis). The detector setup used in the study contains a broad-energy HPGe gamma-ray detector and a position-sensitive alpha detector. Both detectors are connected to a time-stamping event-mode data acquisition system. The method is shown to locate particles with sub-millimetre accuracy and distinguish the interesting particles from non-interesting ones. (author)

British Library Electronic Table of Contents (United Kingdom)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8mA, and a slow photoresponse with a rise time of 5min and a decay time of 7min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the d...

Energy Technology Data Exchange (ETDEWEB)

We studied the effects of small, <20 {micro}m, Te inclusions on the energy resolution of CdZnTe gamma-ray detectors using a highly collimated X-ray beam and gamma-rays, and modeled them via a simplified geometrical approach. Previous reports demonstrated that Te inclusions of about a few microns in diameter degraded the charge-transport properties and uniformity of CdZnTe detectors. The goal of this work was to understand the extent to which randomly distributed Te-rich inclusions affect the energy resolution of CZT detectors, and to define new steps to overcome their deleterious effects. We used a phenomenological model, which depends on several adjustable parameters, to reproduce the experimentally measured effects of inclusions on energy resolution. We also were able to hound the materials-related problem and predict the enhancement in performance expected by reducing the size and number of Te inclusions within ...

British Library Electronic Table of Contents (United Kingdom)

The RD50 collaboration has been exploring the development of radiation hard semiconductor devices for very high-luminosity colliders since 2002. The target fluence to qualify detectors set by the anticipated dose for the innermost tracking layers of the future upgrade of the CERN large hadron collider (LHC) is 1016 1MeV neutron equivalent (neq) cm-2. This is about an order of magnitude higher than the maximum dose for the most exposed silicon detectors in the current machine. RD50 investigates the radiation hardening of silicon sensors from many angles: improvement of the intrinsic tolerance of the substrate material, optimisation of the readout geometry and study of novel design of detectors. A review of some of the recent activities within RD50 is here presented.

Energy Technology Data Exchange (ETDEWEB)

The Bragg-curve detector of the parallel plate ionization chamber type generates a signal that is a distorted replica of the original Bragg-curve. In result of this distortion, the signal peak height is not only a function of the atomic number of the heavy ion, as it is often stated, but also of the particle mass. This mass effect was studied with the aid of computer simulation, and it was found to be dependent on the Frisch grid to anode gap width and on the detector gas. The charge resolution of the detector is affected very significantly by this mass dependence of the signal peak height. Therefore, a careful selection of the detector gas and the grid to anode gap width is necessary, if good charge resolution over a wide range of heavy ions is required.

Science.gov (United States)

Apr 18, 2008 ... The FSS was produced by point-source filtering the individual detector data ... a 1-sigma noise map; and a coverage map giving the count of ...

International Nuclear Information System (INIS)

The Steam Generator (SG) serves as an interface between primary and secondary cycle in Pressurized Heavy Water Reactor (PHWR). Failure of steam generator tubes result in leaking of active heavy water in the secondary closed loop. In Tarapur Atomic Power Station-3 and 4 (TAPS- 3 and 4), Scintillator detectors are provided to detect on line heavy water leakages in SG and moderator heat exchangers by monitoring Nitrogen-16 (16N) and Oxygen-19 (19O) activities. Efficacy of detection of these activities at designed detector position on SG blow down line in presence of background radiation field is analysed theoretically. The count rate of 19O and 16N estimated at the detector position inside Reactor Building (RB) shows that detectors only respond to very high leak rates due to presence of high ambient radiation level even though sensitivity is appreciably good. For detector position in ...

International Nuclear Information System (INIS)

Reducing count losses and pile-up pulse effects in quantitative and qualitative analysis is necessary for accuracy of analysis. Therefore, the optimum peaking time for particular detector systems is important. For this purpose, pure Se and Zn elements were excited by 59.5 keV ?-rays from a 50 mCi 241Am annular radioactive source in this study. The characteristic x-rays emitted from pure Se and Zn elements were detected by using an ultra low energy Ge (Ultra-LEGe) detector connecting Tennelec TC 244 spectroscopy amplifier at different peaking time modes. Overall pulse widths were determined by HM 203-7 oscilloscope connecting amplifier. The proper peaking time for ultra low energy germanium detector (Ultra-LEGe) is determined about 4 ?s.

CERN Document Server

In this note we describe a support structure which will hold detector systems (ITS, TPC, TOF) inside the large solenoid. An overall view of ALICE detector is shown on Fig.1. The support structure consists of 2 rings which fixed to an iron yoke and spokes which connect TPC and TOF to these rings. The ITS is connected by spokes to TPC end caps. Between coils there are 7cm spacings which will allow to fix rings to the yoke this support structure will allow to assemble ITS, TPC and TOF together (Fig.2) somewhere on the surface and then transport to the pit and install in the magnet. Two rings (1) are connected with four bars (2). On the bottom bars there are rolls (3) which will allow smoothly insert detectors into the magnet. Spokes (4) are uniformly distributed.

International Nuclear Information System (INIS)

Researchers at the Laboratory of Nuclear Microanalysis in Besancon (France) are developing and improving radon measurements in order to detect and analyse, more precisely radon emanation anomalies in both fields of Earth Sciences and Radioprotection. In order to characterize radon emanation, two complementary techniques are developed; continuous measurement through a portable proportional counter and passive measurements by nuclear track detectors for both fieldwork and laboratory analysis. A mathematical model is being devised to interpret the nuclear track detector response. This model is performed according to the device characteristics: type of detectors, shape and size of cells and whether a membrane is used or not. In addition to the theoritical study, experimental radon concentration measurements will be reported. (author).

International Nuclear Information System (INIS)

Polish 2001 p. 105 Poland Bogacz, J. Budzanowski, M. Mazur, J. Swakon,

Science.gov (United States)

Mar 1, 2011 ... Currently there is no compact, portable and real time neutron detector instrumentation available for use inside spacecraft or on planetary ...

CERN Document Server

The quantum nature of the electromagnetic field imposes a fundamental limit on the sensitivity of optical precision measurements such as spectroscopy, microscopy, and interferometry. The so-called quantum limit is set by the zero-point fluctuations of the electromagnetic field, which constrain the precision with which optical signals can be measured. In the world of precision measurement, laser-interferometric gravitational wave (GW) detectors are the most sensitive position meters ever operated, capable of measuring distance changes on the order of 10^-18 m RMS over kilometer separations caused by GWs from astronomical sources. The sensitivity of currently operational and future GW detectors is limited by quantum optical noise. Here we demonstrate a 44% improvement in displacement sensitivity of a prototype GW detector with suspended quasi-free mirrors at frequencies where the sensitivity is shot-noise-limited, by ...

Energy Technology Data Exchange (ETDEWEB)

The control valve for a large steam turbine must be operated linearly to be run by an automatic control system in a power plant. It is, however, found that the flow increase is much greater for a given valve position change near the closed end of travel than it is near the open end. Accordingly, the desired linearization will be achieved if the valve is opened less near the closed end of travel and greater near the open end. The previous way for linearization was to utilize the cams, which is called the mechanical hydraulic control (MHC). The MHC was afterward improved by producing the nonlinear electric compensation to the nonlinear system of control valves, viz. the electro hydraulic control (EHC). This paper addresses the principle of linearization.

International Nuclear Information System (INIS)

The Feynman-#alpha# method was applied to measurement of reactivity and the ability of this method for a real-time reactivity monitoring system was assessed. In the experiment, all measured data by BF_3 detectors were stored in a multi-channel scaler controlled by a personal computer, and they were analyzed to obtain prompt neutron decay constant (#alpha#) and reactivity with consideration of dead time of detector. It was found that #alpha# could be obtained almost in a real-time even for both positive and negative reactivities by the present experimental technique. (author).

Energy Technology Data Exchange (ETDEWEB)

Disclosed herein is a radiation detector providing for the in situ automatic sampling of fluids containing substances emitting radiation, especially Cerenkov radiation. The detector permits sampling within well casings and is self-purging such that no additional provisions must be established for the storage and disposal of contaminated fluids.

International Nuclear Information System (INIS)

Radon concentration measurement in the ground can be used for the prospecting for uranium and earthquake prediction. Some results of radon concentration measurement in the soil are presented here. The moisture condensation at the detector surface can affect on the detection efficiency. Due to this problem we tested a few filter papers on water permeability. The ratio of track densities on solid state nuclear track detector (SSNTD) in the open and the closed diffusion chamber is also determined. (author)

International Nuclear Information System (INIS)

We describe the continued development of a portable, real-time neutron spectrometer. The spectrometer is composed of two distinct detector systems: a Helium 3 gas filled proportional counter for the lower neutron energy interval between 20 KeV and 2 MeV and a bulk silicon solid state detector for the higher energy interval between 2 MeV and 500 MeV. Modeling and experimental results with mono-energetic neutron beams are reported.

Energy Technology Data Exchange (ETDEWEB)

The transition radiation detector (TRD) for the D{Phi} experiment is currently in operation at Fermilab. Transition radiation production, which has been clearly observed in the collider data, makes the TRD a valuable tool to discriminate electrons and hadrons. We describe an algorithm based on the truncated energy, and illustrate its use for top signal and background. (authors). 7 refs., 6 figs., 2 tabs.

International Nuclear Information System (INIS)

A large Bragg-curve spectrometer has been constructed and tested. The detector has a cylindrical geometry and operates with a homogeneous electric field. Energy resolutions of <0.8% and Z resolutions of Z/#DELTA#Z=80 have been achieved for eleastically scattered "5"8Ni ions. These results demonstrate the suitability of this large solid-angle detector for use in a wide variety of heavy-ion scattering experiments. (orig.).

Energy Technology Data Exchange (ETDEWEB)

A multi-spectral Schottky barrier infrared detector array in which individual pixels of radiation from a remote radiating object are detected by two or more Schottky barrier infrared radiation detectors each having a different spectral response so as to provide a ''color'' discrimination for the array.

International Nuclear Information System (INIS)

This study mainly concerns medical explorations by radioisotopes. Detectors with medical exams and applications are described. Ionisation chambers, semiconductor detectors and scintillation counters are also presented. Uses of radioisotopes in medicine in vivo and in vitro techniques are explained. Examples of scintiscanning are given like: angiography, nuclear cardiography and thyroid scintiscanning. The importance of the study is to present a panorama of nuclear medicine laboratories -at the time- in hospitals in Lebanon.

International Nuclear Information System (INIS)

We have investigated the detection performance of GaAs detectors made with different thickness and contact geometries. A comparison is made between these detection capabilities and the imaging requirements for the following medical applications: digital mammography, digital chest radiography and nuclear medicine. Experimental results and preliminary images are presented and discussed. (author)

Energy Technology Data Exchange (ETDEWEB)

The history of explosives vapor detection includes almost every detection strategy known to man. Initial attempts to utilize these techniques were dismal failures. However, with the development of the Electron Capture Detector (ECD), the first promising detection of explosives vapors became possible. The present commercial explosives detectors detect the higher vapor pressure materials but not the whole spectrum. This paper describes the basic properties of explosives molecules and our research to utilize these properties for increased detection sensitivity.

Energy Technology Data Exchange (ETDEWEB)

In 1998, research began at Idaho National Engineering and Environmental Laboratory to investigate the application of {sup 6}Li and {sup 7}Li isotopes to the measurement of neutron and gamma radiation. Various size pairs of {sup 6}Li and {sup 7}Li based detectors were exposed to mixed neutron and gamma radiation. Experiments demonstrated that these detectors could be used to measure low level neutron radiation in the presence of high level gamma radiation. (author)

Energy Technology Data Exchange (ETDEWEB)

The kinetic parameters, ..cap alpha.. the coupling coefficient and tau-bar the mean neutron transit time have been determined using a reactor oscillator on the coupled-core of the Queen Mary College research reactor. By using correlation techniques it has proved possible to use detectors small enough to be inserted in the fuel tanks. It is shown that the simplified Baldwin model with one-group diffusion theory is inadequate to describe the kinetic behaviour and the experimentally-determined parameters are dependent upon the positioning of the detectors.

International Nuclear Information System (INIS)

The working group reviewed the main difficulties foreseen in doing physics at a gamma-gamma collider. They discussed the requirements for the detector, calculated some of the signal and background rates, compared methods of measuring luminosity, looked at how to get the laser beams in, investigated ways of sweeping aside the electrons and considered ways of disposing of the used beams. No overwhelming obstacles were found but important questions still need to be answered. ((orig.)).

Science.gov (United States)

A system for inspecting a ceramic component. The ceramic component is positioned on a first rotary table. The first rotary table rotates the ceramic component. Light is directed toward the first rotary table and the rotating ceramic component. A detector is located on a second rotary table. The second rotary table is operably connected to the first rotary table and the rotating ceramic component. The second rotary table is used to move the detector at an angle to the first rotary table and the rotating ceramic component.

International Nuclear Information System (INIS)

The purpose of this research was to: a) evaluate variations in sensitivity and uniformity of SPECT detectors during 360"0 rotation, b) explore the causes of the variations and c) to discuss a correction procedure. A flood source consisting of a lucite disc 47.7 cm in diameter containing 3 microcuries of Co-57 was constructed. This source can be firmly attached to the uncollimated detector guaranteeing no detector-source geometry change during rotation. Four different SPECT cameras were tested. Measurements were obtained at 45"0 intervals throughout a 360"0 rotation, and repeated in 3 different orientations with respect to the earth's magnetic field. In one camera the effects of the direction and strength of induced magnetic fields were studied. All detectors showed cyclic rotational variations in sensitivity; in three cameras 6%, in one 3%. The amplitude and phase of the sensitivity variation curves and ...

International Nuclear Information System (INIS)

The Steam Generator (SG) serves as an interface between primary and secondary cycle in Pressurized Heavy Water Reactor (PHWR). Failure of steam generator tubes result in leaking of active heavy water in the secondary closed loop. In Tarapur Atomic Power Station-3 and 4 (TAPS- 3 and 4), Scintillator detectors are provided to detect on line heavy water leakages in SG and moderator heat exchangers by monitoring Nitrogen-16 ("1"6N) and Oxygen-19 ("1"90) activities. Efficacy of detection of these activities at designed detector position on SG blow down line in presence of background radiation field is analysed theoretically. The count rate of "1"9O and "1"6N estimated at the detector position inside Reactor Building (RB) shows that detectors only respond to very high leak rates due to presence of high background even though sensitivity is appreciably good. For detector position out side ...

Energy Technology Data Exchange (ETDEWEB)

The advanced detector development project at the University of Michigan has completed the first full year of its current funding. Our general goals are the development of radiation detectors and spectrometers that are capable of portable room temperature operation. Over the past 12 months, we have worked primarily in the development of semiconductor spectrometers with {open_quotes}single carrier{close_quotes} response that offer the promise of room temperature operation and good energy resolution in gamma ray spectroscopy. We have also begun a small scale effort at investigating the properties of a small non-spectroscopic detector system with directional characteristics that will allow identification of the approximate direction in which gamma rays are incident. These activities have made use of the extensive clean room facilities at the University of Michigan for semiconductor device fabrication, and also the radiation ...

Energy Technology Data Exchange (ETDEWEB)

A large-acceptance Bragg curve spectrometer with a longitudinal electron collection field and a segmented anode has been constructed and tested. The effects on the charge resolution of the entrance angle and entrance position of the incident particle have been studied. Simulations have been done in order to isolate the contribution to the overall detector performance of the signal-shaping electronics from that of the intrinsic design of the detector. ((orig.))

CERN Document Server

Cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) have been regarded as promising semiconductor materials for hard X-ray and Gamma-ray detection. The high atomic number of the materials (Z_{Cd} =48, Z_{Te} =52) gives a high quantum efficiency in comparison with Si. The large band-gap energy (Eg ~ 1.5 eV) allows us to operate the detector at room temperature. However, a considerable amount of charge loss in these detectors produces a reduced energy resolution. This problem arises due to the low mobility and short lifetime of holes. Recently, significant improvements have been achieved to improve the spectral properties based on the advances in the production of crystals and in the design of electrodes. In this overview talk, we summarize (1) advantages and disadvantages of CdTe and CdZnTe semiconductor detectors and (2) technique for improving energy resolution and photopeak efficiencies. Applications of these ...

CERN Document Server

A new monolithic semi-insulating (SI) GaAs sensor design for X-ray imaging applications between 10-100keV has been proposed. Monolithic pixel detectors offer a number of advantages over hybrid bump-bonded detectors, such as high device yield, low costs and are easier to produce large scale arrays. In this thesis, an investigation is made of the use of a SI GaAs wafer as both a detector element and substrate for the epitaxially grown High Electron Mobility Transistors (HEMTs). The design of the HEMT transistors, optimised for this application, were produced with the aid of the Silvaco 'Virtual Wafer Fab' simulation package. It was determined that the device characteristics would consist of a small positive threshold voltage, a low off-state drain current and high transconductance. The final HEMT transistor design, that would be integrated to a pixel detector, had a threshold voltage of 0.17V, an ...

International Nuclear Information System (INIS)

Lanthanum halide (LaBr_3:Ce) scintillators offer significantly better resolution (< 3% at 662 keV) relative to NaI(Tl) and have recently become commercially available in sizes large enough for the handheld, Radio-Isotope Identification Device (RIID) market. Drawbacks to lanthanum halide detectors, however, include internal radioactivity contributing to spectral counts, and a low-energy response which can cause detector resolution to be worse than that of NaI(Tl) below 100 keV. To study the potential of this new material for RIIDs we performed a series of measurements comparing a 1.5 x 1.5-inch LaBr_3:Ce detector with an Exploranium GR-135 RIID, which contains a 1.5 x 2.2-inch NaI(Tl) detector. Measurements were taken for short timeframes, as typifies RIID usage. Measurements included examples of naturally occurring radioactive material (NORM), typically found in cargo, and special nuclear materials. ...

Science.gov (United States)

A previous paper introduced the use of wave digital filters as a basic building block for power system simulation, particularly suitable for real-time applications. This paper stresses the simulation of non-linear and switching elements, emphasizing the advantages of the wave filters implementation. The digital structure is maintained even when non-linear components change their characteristics or power electronic devices switch their states. As a very important by-product, the suppression of numerical oscillations related to the trapezoidal rule is achieved in a rather simple way, with no effects on simulation results.

International Nuclear Information System (INIS)

In this paper we study the behavior of the solutions of quasi-linear Dirichlet problems when the principal parts H-converge and when the lower order terms have quadratic growth with respect to the gradient. We show that the limit problem consists of a principal part which is the H-limit of the principal parts and of the lower order term which is constructed from the corresponding terms by using a linear corrector result. We assume only natural hypotheses on the correctors (i.e. L"2 equi-integrability and not L"#infinity# boundedness). (author)

International Nuclear Information System (INIS)

A theory of the asymptotic functions for the case of many variables is presented. It is shown that the class F(R"N) of these generalized functions is closed in respect to the linear algebraic and analytic operations, multiplication as well as a set of linear and polynomial changes of the variables. The existence in F(R"N) of analogues (consistent with the linear operations) of the Schwartz distributions with point support is proved. In terms of these analogues, some formulae for singular products and changes of variables of the Dirac #delta#-function and its derivatives #delta#"("i")(x), x is an element of R"N, are given. (author). 14 refs.

Energy Technology Data Exchange (ETDEWEB)

The security of ports and transportation is of utmost importance for the development of economy and the security of a nation. Among the necessary actions to ensure the security of ports and borders, the inspection of containers is one of the most time consuming and expensive procedures. Potential threats are the illegal traffic of radioactive materials that could be employed for the construction of weapons, as uranium and plutonium. New techniques for the inspections of containers should be fast, allow the detection and identification of dangerous materials, and be non-invasive, to reduce costs and delays. We propose to build a large surface photon and neutron detector based on plastic scintillator to identify the presence of fissile or fertile material inside a container. The detector consists of scintillator bars, wrapped in thin foils of reflecting material containing gadolinium for neutron capture and arranged in planes separated by ...

Science.gov (United States)

pletely new PW fuel cell model had to be developed for CINDA. Several ...... following linear equation, which is used in the SINDA fuel cell model: ...

Science.gov (United States)

The aim of this paper is to illustrate the validity and efficiency of iterative methods for solving large linear systems arising from the finite element discretization of the equation governing conduction-controlled solidification processes. Starting from the basic enthalpy equation, two alternative formulations are obtained and fixed-grid finite element discretizations are developed. These discretizations yield a set of nonlinear equations that are linearized using the Newton-Raphson scheme. The linearized equations are used as a basis for evaluating different iterative methods of the conjugated gradient type. Symmetric scaling and incomplete factorization preconditioning of the linear equations are used to improve the convergence properties of the iterative methods. Vectorization and parallelization are also employed to make full use of the CRAY-2 supercomputer. The results indicate that the ...

CERN Document Server

Hidden Markov models (HMMs) are probabilistic functions of finite Markov chains, or, put in other words, state space models with finite state space. In this paper we examine subspace estimation methods for HMMs whose output lies a finite set as well. In particular we study the geometric structure arising from the non-minimality of the linear state space representation of HMMs, and consistency of a subspace algorithm arising from a certain factorisation of the singular value decomposition of the estimated linear prediction matrix. For this algorithm we show that the estimates of the transition and emission probability matrices are consistent up to a similarity transformation, and that the m-step linear predictor computed from the estimated system matrices is consistent, i.e. converges to the true optimal linear m-step predictor.

CERN Document Server

Peculiar velocities induce apparent line of sight displacements of galaxies in redshift space, distorting the pattern of clustering in the radial versus transverse directions. On large scales, the amplitude of the distortion yields a measure of the dimensionless linear growth rate \\ff of fluctuations, which is related to the cosmological density \\Omega and the linear bias factor b in linearly biassed standard cosmology by \\ff \\approx \\Omega^{0.6} /b. To make the maximum statistical use of the data in a wide angle redshift survey, and for the greatest accuracy, the spherical character of the distortion needs to be treated properly, rather than in the simpler plane parallel approximation. In the linear regime, the redshift space correlation function is described by a spherical distortion operator acting on the true correlation function. It is pointed out here that there exists an operator, which is ...

Energy Technology Data Exchange (ETDEWEB)

In this paper, research on pass schedule of tandem cold mill (TCM) is carried out. According to load (reduction, rolling force, motor power) balance, non-linear equations set with variables of inter-stand thickness is constructed. The pass schedule optimization is carried out by solving the non-linear equations set. As the traditional method, the Newton-Raphson method is used for solving the non-linear equations set. In this paper a new simple method is brought up. On basis of the monotone relations between thickness and load, the inter-stands thickness is adjusted dynamically. The solution of non-linear equations set can be converged by iterative calculation. This method can avoid the derivative calculation used by traditional method. So, this method is simple and calculation speed is high. It is suitable for on-line control. (author)

Science.gov (United States)

... Results of the AXI5345-18 Motor, Jeti Spin 99 Controller and the APC 27 x 13 Propeller in use with a Linearized Fuel Cell Model Assuming Voc ...

Science.gov (United States)

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Science.gov (United States)

... Richrd Bals andLina PrissJames Lepowsky and Mirko Primc Richard Beaals, and Linda Preiss Rothschild, Editors 47 Linear algebra and its role in ...

International Nuclear Information System (INIS)

We investigate the possibility of implementing a given projection measurement using linear optics and arbitrarily fast feedforward based on the continuous detection of photons. In particular, we systematically derive the so-called Dolinar scheme that achieves the minimum-error discrimination of binary coherent states. Moreover, we show that the Dolinar-type approach can also be applied to projection measurements in the regime of photonic-qubit signals. Our results demonstrate that for implementing a projection measurement with linear optics, in principle, unit success probability may be approached even without the use of expensive entangled auxiliary states, as they are needed in all known (near-)deterministic linear-optics proposals.

Science.gov (United States)

Generalized linear models (GLMs), as defined by J. A. Nelder and R. W. M. Wedderburn (1972), unify a class of regression models for categorical, discrete, and continuous response variables. As an extension of classical linear models, GLMs provide a common body of theory and methodology for some seemingly unrelated models and procedures, such as the logistic, Poisson, and probit models, that are increasingly used in family studies. This article provides an overview of the principle and the key components of GLMs, such as the exponential family of distributions, the linear predictor, and the link function. To illustrate the application of GLMs, this article uses Canadian national survey data to build an example focusing on the number of close friends among older adults. The article concludes with a discussion of the strengths and weaknesses of GLMs.

Science.gov (United States)

and shock induced flow separation may significantly affect the flutter ...... Aerodynamic and Aeroelastic Simulation, AGARD Report 822, 10-1 10-20. ...

British Library Electronic Table of Contents (United Kingdom)

Metallic Zn films were deposited on glass substrates by electron-beam evaporation. ZnO films were synthesized by thermal oxidation of Zn metallic films in air. At the annealing temperature of 550 ?C, ZnO nanowires appeared on the surface, which mainly result from the decrease of oxidation rate. A ZnO ultraviolet photodetector was fabricated based on a metal-semiconductor-metal planar structure. The detector showed a large UV photoresponse with an increase of two orders of magnitude. It is concluded that promising UV detectors can be obtained on ZnO films by thermal oxidation of Zn metallic films. The ways of performing spectral response measurements for polycrystalline ZnO films are also discussed.

Energy Technology Data Exchange (ETDEWEB)

In this talk, we summarize recent results obtained from the combined neutrino telescopes IceCube and AMANDA. The combined approach, including data taken from both detectors simultaneously, is compared to other analyses that are using IceCube only data. The main benefit of the combined detector is its improved performance at low energies, meaning energies below 1 TeV (close to the energy threshold of the detector). The discussion is focused on the search for extra-terrestrial neutrinos from candidate sources in our Galaxy. Using appropriate cuts, the sensitivity can be optimized for soft spectra neutrino sources. With the resulting data sample, several studies are performed: an unbinned Galactic Plane Scan and a Cygnus region analysis: the Multi Point Source analysis. The current status of these analyses is presented.

International Nuclear Information System (INIS)

The two most important issues in designing future gravitational wave interferometric detectors are, in our opinion, thermal and optical noise. In this paper we discuss some approaches for reducing these noises. About thermal noise we show a possible cryogenic solution. About optical noise (namely, the combined effect of shot noise and radiation pressure noise) we show that it is possible to apply a recently proposed reduction strategy based on a 'quantum feedback' (Courty et al 2003 Phys. Rev. Lett. 90 083601; Courty et al 2003 Preprint gr-qc/0301068) to a full Fabry-Perot cavity. This can be seen as a further step towards the practical realization of a detector which is able to evade the standard quantum limit.

International Nuclear Information System (INIS)

A multiwire proportional counter type detector with thin slits instead of wires is presented. It can detect either charged particles (positive or negative) or radiation. The detector can be used as a counter or as an image converter. In radiography, it can replace photographic film or TV camera systems. It can also be used to measure particle or radiation energy. The slits which replace wires in the anode are introduced between two parallel microstrip conductors with different potentials. A quasi-polar electric field is produced between these strips. To obtain high fields, the slits are extremely narrow. Microstrips less than a micron can be obtained, giving structural dimensions of a few microns, i.e., 100 times smaller than the spacing in a classic wire anode.

International Nuclear Information System (INIS)

A mathematical model of multichannel radiometric inspection system was developed, in which the measurement results are reproduced in the form of a half-tone image equivalent to the radiation image of the irradiated object. The model makes the following assumptions: the beam of radiation is fan-shaped; the object of inspection is scanned discretely; the focal spot of the source is rectangular; the apertures of the detector are round, and the detectors themselves are equidistant from the sources, aimed at it, and form a close-packed array; the signals from the detectors are processed according to a time scheme; and the measurement results are corrected in a computer for normalizing the gains of the channels of the system. The mathematical model can serve as the basis for developing a method of calculating the optimal parameters of a multichannel radiometric system with visualization of the radiation images. 14 refs., 2 figs.

Energy Technology Data Exchange (ETDEWEB)

Many nondestructive beam position monitors are known. However, these devices can not be used for DC particle beam diagnostics. We investigated a method of beam diagnostics applicable for the operative control of DC high power e-beam inside closed waveguide. A design of the detector for determination of{open_quote} center of mass {close_quote} position of DC particle beam was developed. It was shown that the monitor can be used as a nondestructive method for the beam position control in resonators. Magnetic field of the particle beam outside a resonator is used. The detector consists of the steel yokes and magnetic field sensors. The sensors measure magnetic fluxes in the steel yokes fixed outside the resonator. When the particle beam changes its position, these magnetic fluxes also change. Beam displacement sensitivity of the monitor depends on the steel yoke dimensions. The detector sensitivity is equal to 1 Gauss/mm for ...

Energy Technology Data Exchange (ETDEWEB)

A passive dosemeter, based on a Makrofol ED track detector covered with aluminized Mylar, enclosed in diffusion chamber, has been used for radon concentration studies. Detectors have been irradiated, using a {sup 241}Am source, at different energies and fluences in order to obtain the electrochemical etching conditions that allow the optimum registration of alpha particles having energies over 3 MeV. Thirty dosemeters have been sent to the UK National Radiation Protection Board (NRPB) Radon Environmental Chamber for calibration. The sensitivity of the dosemeter has been calculated. Several dosemeters have also been exposed in houses and dwellings in the Barcelona and Madrid areas for monitoring. Values for radon concentration in the areas under study are presented. (author).

British Library Electronic Table of Contents (United Kingdom)

Indoor and soil gas Radon (222Rn) concentration measurements were accomplished in two stages in Sivas, a central eastern city in Turkey. In the first stage, CR-39 passive nuclear track detectors supplied by the Turkish Atomic Energy Authority (TAEA) were placed in the selected houses throughout Sivas centrum in two seasons; summer and winter. Before the setup of detectors, a detailed questionnaire form was distributed to the inhabitants of selected houses to investigate construction parameters and properties of the houses, and living conditions of inhabitants. Detectors were collected back two months later and analysed at TAEA laboratories to obtain indoor 222Rn gas concentration values. In the second stage, soil gas 222Rn measurements were performed using an alphameter near the selected h...

International Nuclear Information System (INIS)

An iterative phase retrieval algorithm was previously investigated for in-line x-ray phase imaging. Through detailed theoretical analysis and computer simulations, we now discuss the limitations, robustness, and efficiency of the algorithm. The iterative algorithm was proved robust against imaging noise but sensitive to the variations of several system parameters. It is also efficient in terms of calculation time. It was shown that the algorithm can be applied to phase retrieval based on one phase-contrast image and one attenuation image, or two phase-contrast images; in both cases, the two images can be obtained either by one detector in two exposures, or by two detectors in only one exposure as in the dual-detector scheme.

CERN Document Server

We report on aging measurements of a photon detector candidate for the HERA-B RICH. The prototype, a proportional wire chamber operated with TMAE, was mounted on an argon filled test-beam RICH and was aged by UV light at rates we expect in HERA-B. We monitored gain and current continuously, and checked the chamber with Cherenkov photons at regular intervals. The number of detected photons/track (projected to 2.75 m C sub 4 F sub 1 sub 0 in HERA-B) dropped from 26 to 11 after two days of aging - well below the 20 required for pi/K separation. Based on these results, HERA-B decided to use multi-anode PMTs as photon detectors in the RICH.

British Library Electronic Table of Contents (United Kingdom)

An analytical method was proposed for calculating radiative fluxes incident on a planar circular detector from a volume multiple point chemi- or bio-luminescent source inside a coaxial cylindrical reactor. The method was designed for a cylindrical reactor when the surface reflections were neglected and when chemi- or bio-luminescence reaches a detector embedded in the same homogeneous optical medium as the point emitters of the volume multiple point source model. The radiative fluxes from arbitrarily distributed point emitters were expressed by one generalized quadruple-integral formula. Then some double- and single-integral formulas were obtained for calculating radiative fluxes from identically radiating point emitters uniformly distributed within the reactor. Selected results were compu...

International Nuclear Information System (INIS)

An indoor radioactive survey is being conducted in an Italian district. Preliminary results identified a zone with significant radioactive levels, in which a new specific survey has been planned. In this paper attention is dedicated mainly to radon measurement technique and results.

CERN Document Server

PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature in a wide energy range (protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the study of the antimatter component: antiprotons (80 MeV-190 GeV), positrons (50 MeV-270 GeV) and search for antimatter with a precision of the order of $10^{-8}$). The experiment, housed on board the Russian Resurs-DK1 satellite, was launched on June, 15 2006 in a $350\\times 600 km$ orbit with an inclination of 70 degrees. The detector is composed of a series of scintillator counters arranged at the extremities of a permanent magnet spectrometer to provide charge, Time-of-Flight and rigidity information. Lepton/hadron identification is performed by a Silicon-Tungsten calorimeter and a Neutron detector placed at the bottom of the device. An Anticounter system is used offline to reject false triggers coming from the ...

UK PubMed Central (United Kingdom)

To treat or prevent some of the 795,000 annual strokes in the U.S., self-expanding endo-vascular stents deployed under fluoroscopic image guidance are often used. Neuro-interventionalists need...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This report discusses the following topics: Fusion-fission in light nuclear systems; High-resolution Q-value measurement for the {sup 24}Mg+{sup 24}Mg reaction; Heavy-ion reactions and limits to fusion; and Hybrid MWPC-Bragg curve detector development.

Energy Technology Data Exchange (ETDEWEB)

The development and evaluation of a post-column reaction detector sensitive to platinum(II) complexes is presented in which sodium bisulfite is used as the derivatizing agent with potassium dichromate as an activating agent. The influences of mobile phase changes (i.e., pH, organic modifiers, electrolytes), oxygen, metal ions, and order of reagent addition on reaction kinetics and product yield are defined and used in optimization of detector response. Detection at lambda/sub max/ 290 nm results in an on-line post-column sensitivity of 40-60 ng/mL for selected cis-dichloroplatinum complexes and a sensitivity of 300-1200 ng/mL for four (substituted)-malonato-platinum complexes. The reaction detector is used to monitor the kinetics of aquation of cisplatin (CDDP) and to quantitate CDDP degradation in plasma. As the sensitivity for CDDP in plasma is comparable to that achieved from high pressure liquid chromatography (HPLC) ...

Energy Technology Data Exchange (ETDEWEB)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360 nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8 mA, and a slow photoresponse with a rise time of 5 min and a decay time of 7 min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the decrease of the barrier height between crystallites. The relaxation time constant {tau} obtained from the curve fitting represents the ...

Energy Technology Data Exchange (ETDEWEB)

GaN and Al{sub 1{minus}x}Ga{sub x}N films were grown by the method of ECR-MBE. Absorption constants as a function of wavelength were determined from transmission measurements. Photoconducting detectors were fabricated from these films and characterized in terms of their spectral response and photoconductive gain. Mobility-lifetime products were determined from the measurement of photoconductive gain. The resistivity and mobility-lifetime products of the films were varied from 10--10{sup 9} ohm-cm and 10{sup {minus}3}--10{sup {minus}8} cm{sup 2}/V respectively by changing the microwave power in the ECR discharge from 20--60 watts. The change in the mobility-lifetime product is attributed to change in the lifetimes of the photogenerated carriers. This assumption is supported by direct measurement of detector response times. Finally, the authors report for the first time, the detection of alpha particles using GaN detectors.

UK PubMed Central (United Kingdom)

ObjectiveThis study discusses an appropriate framework to measure system performance for the task of neonatal seizure detection using EEG. The framework is used to present an extended...Full Text Available

CERN Document Server

ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). Some specific calibration tasks are performed regularly for each of the 18 ALICE sub-detectors in order to achieve most accurate physics measurements. These procedures involve events analysis in a wide range of experimental conditions, implicating various trigger types, data throughputs, electronics settings, and algorithms, both during short sub-detector standalone runs and long global physics runs. A framework was designed to collect statistics and compute some of the calibration parameters directly online, using resources of the Data Acquisition System (DAQ), and benefiting from its inherent parallel architecture to process events. This system has been used at the experimental area for one year, and includes more than 30 ...

International Nuclear Information System (INIS)

The experiments at the incinerator for low-level wastes processing, (containing transuranium radionuclides) are described. Air decontamination factors and detector readings correction factors for efficiency and absorption are indicated.

UK PubMed Central (United Kingdom)

The reference medium for brachytherapy dose measurements is water. Accuracy of dose measurements of brachytherapy sources is critically dependent on precise measurement of the source–detector...Full Text Available

International Nuclear Information System (INIS)

In this study, a miniature fiber-optic radiation detector has been developed using a water-equivalent organic scintillator for electron beam therapy dosimetry. Usually, two kinds of light signals such as fluorescent and Cherenkov lights are generated in a fiber-optic radiation detector when a high-energy electron beam is irradiated. The fluorescent light signal is produced in the scintillator and is transmitted through a plastic optical fiber to a remote light-measuring device such as a PMT or a photodiode. The Cherenkov light could be also produced in the plastic optical fiber itself and be detected by a light-measuring device. Therefore, it could cause problems or limit the accuracy of the detection of a fluorescent light signal that is proportional to dose. The objectives of this study are to measure, characterize and eliminate Cherenkov light generated in a plastic optical fiber used as a component of a fiber-optic radiation ...

Energy Technology Data Exchange (ETDEWEB)

A novel approach to the Bragg curve spectroscopy is utilized to construct a charged particle detector which makes fragment elemental identification and energy measurement possible. The advantage of the construction includes good timing and spectroscopic properties with a very low energy threshold. ((orig.))

Energy Technology Data Exchange (ETDEWEB)

Activities are reported by the Reactor Systems Section, Research Instrument Section, and the Measurement and Controls Engineering Section. Reactor system activities include dynamic analysis, survillanc and diagnostic methods, design and evaluation, detectors, facilities support, process instrumentation development, and special assignments. Activities in the Research Instrument Section include the Navy-ORNL RADIAC development program, advanced ..gamma.. and x ray detector systems, neutron detection and subcriticality measurements, circuit development, position-sensitive detectors, stand-alone computers, environmental monitoring-detectors and systems, plant security, engineering support for fusion energy division, engineering support for accelerator physics, and communications: radio, closed-circuit tv, and computer. Activities in the Measurement and Controls Engineering Section include the AVLIS program; ...

International Nuclear Information System (INIS)

Some results of the indoor radon measurements are presented in this paper. Kodac track detectors LR-115 were used for these measurements. Average winter/spring ratio for indoor radon concentration was determined from the results obtained and is presented in this paper. (author).

Energy Technology Data Exchange (ETDEWEB)

The following topics are dealt with: Detectors at COSY, major physics results at COSY, physics at external facilities, theoretical investigations, COSY operation and developments, preparations for FAIR, technical developments. (HSI)

Energy Technology Data Exchange (ETDEWEB)

Explosives molecules have a number of unique properties. These properties are discussed. They include low vapor pressures, electronegativity, ''stickiness,'' frangibility, and thermal instability. The program for developing an advanced explosives detector is described.

CERN Document Server

Reactor neutrinos play an important role in determining parameter theta_{13} in the lepton mixing (PMNS) matrix. Next important step on measuring PMNS matrix could be to build another reactor neutrino experiment in DaYa bay, China, to search the possible oscillations via sin^2 (2theta_{13}) and Delta m^2_{13}. We consider 4 different schemes for positions of three 8-ton detectors of this experiment, and simulate the results with respect to an array of assumed ''true'' values of physics parameters. Using three kinds of analysis method, we suggest a best scheme for DaYa-Bay which is to place a detector 2200m ~ 2500m symmetrically away from two reactors, and to put the other two detectors closer to their corresponding reactors respectively, almost at a 100m \\~ 200m distance. Moreover, with conservative assumption on the experimental technique, we construct series of allowed regions from our simulation results, and give ...

International Nuclear Information System (INIS)

AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft tissue detail. CONCLUSION: In some of the observed image quality aspects, the ...

International Nuclear Information System (INIS)

In many experiments involving fast neutrons generated in nuclear reactions initiated by accelerator produced charged particle beams, it is important to be able to determine accurately the neutron yield from the target. A detector suitable for such applications should have: a constant efficiency over a large energy range; a fast time response; and the ability to discriminate between gamma rays and neutrons. The authors have constructed a open-quotes black neutron detectorclose quotes based on the design of Poenitz that has these characteristics. At the Lowell Van de Graaff accelerator laboratory neutrons are produced via the "7Li(p,n)"7Be reaction using a pulsed proton beam which impinges on metallic lithium targets. The pulsed beam enables the detector to be used in a time-of-flight spectrometer. Use of BC501 liquid scintillator permits neutron-gamma discrimination. The scintillator is viewed by five RCA 48796 photo tubes. The ...

Energy Technology Data Exchange (ETDEWEB)

Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world, and thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. Reported here are the results of tests of a newly designed boron-lined ...

Energy Technology Data Exchange (ETDEWEB)

The research on the therapy of brain tumors and others by the thermal neutron irradiation using research reactors is to kill tumor cells by accumulating boron at a tumor part, and using {alpha} particles and {sup 7}Li generated by {sup 10}B(n, {alpha}){sup 7}Li reaction of thermal neutrons, which is known as boron neutron capture therapy (BNCT). In Japan Atomic Energy Research Institute, the medical irradiation facility was installed in the thermal neutron column of the JRR-2, and as of March, 1994, 22 cases of irradiation have been carried out. In order to monitor the variation of thermal neutron flux during irradiation, the real time measurement using a simultaneous monitor is carried out, but there is the variation of measured values in the Si semiconductor, p-n junction detector possibly due to its direction dependence. The experiment was carried out to quantity the direction dependence of the detector by using the neutron radiography ...

Energy Technology Data Exchange (ETDEWEB)

We investigate the possibility of observing strong interactions of longitudinally polarized weak vector bosons in the process {gamma}{gamma}{yields}ZZ at a photon linear collider. We make use of polarization of the photon beams and cuts on the decay products of the Z bosons to enhance the signal relative to the background of transversely polarized ZZ pairs. We find that the background overwhelms the signal unless there are strong resonant effects, as for instance from a technicolor analogue of the hadronic f{sub 2}(1270) meson. ((orig.)).

CERN Document Server

A quantitative description is presented of the non-linear current-voltage response in superconducting niobium cavities for accelerator application. It is based on a fit for a large sample of data from cavity tests of different kind. Trial functions for the surface resistance describing this non-linear relation are established by a least square data fit. Those trial functions yielding the best fit are quantitatively explained by basic physics.

International Nuclear Information System (INIS)

Analytical expressions for thermoluminescence (TL) dating based on the modified Zimmerman model were derived. The non-linear behaviour of TL sensitivity is reexamined and is found to be due to electron capturing competitions in both test-dose excitation and the readout stages. A curve fitting method is proposed to determine the paleodose for the additive dose dating method. The multiple activation technique is also investigated, from which the paleodose should be regarded as an upper limit.

Energy Technology Data Exchange (ETDEWEB)

We discuss the main stages of a physical program for photon linear colliders. We consider the problems in electroweak theory, hadron physics, QCD, and nonlinear QED, as well as new particles and interactions, etc. The discussed stages constitute the parts of an entire ambitious program for linear colliders. ((orig.)).