Energy Technology Data Exchange (ETDEWEB)

A method, system and a radiation detector system for use therein are provided for determining the depth distribution of radiation-emitting material distributed in a source medium, such as a contaminated field, without the need to take samples, such as extensive soil samples, to determine the depth distribution. The system includes a portable detector assembly with an x-ray or gamma-ray detector having a detector axis for detecting the emitted radiation. The radiation may be naturally-emitted by the material, such as gamma-ray-emitting radionuclides, or emitted when the material is struck by other radiation. The assembly also includes a hollow collimator in which the detector is positioned. The collimator causes the ...

Energy Technology Data Exchange (ETDEWEB)

This report covers the gamma detectors, measurement instrumentation, and testing results of a system developed at Los Alamos National Laboratory. This system monitors the process liquid waste streams at the Plutonium Facility (TA-55) for the presence of radioactive contamination. The detectors are at various points on the acid, caustic, and industrial waste lines. Two of the detectors are on the sanitary sewer lines from the facility. A custom interface unit associated with these two detectors furnishes the facility operation center with a notification of the detection of material. All of the detectors furnish measurement information to a central computer system for storage and trending.

International Nuclear Information System (INIS)

An imaging position sensitive detector for charged particles, neutrons, X-and gamma rays has been developed. The novel feature of this scintillation imaging radiation detector is its ability to detect individual nuclear particle scintillations with a h igh degree of spatial resolution. The key elements of this detector system are a high gain, low noise image intensifier tube, a CCD camera and commercially available image processing hardware and software. This detector system is highly effective for applications such as low fluence and real time neutron radiography, mapping of radioactive contamination in nuclear reactor fuel rods, X-ray diffraction imaging, high speed autoradiography and in general position sensitive detection of nuclear radiation. Results of some of the exploratory experiments carried out using this ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

A circumsolar telescope for determining the flux of energy from the sun and from the circumsolar region as a function of angle, wavelength, and atmospheric conditions is presented. The telescope system consists of a specially designed scanning telescope, an electronic control and recording system and some auxiliary equipment. The detector is a pyroelectric crystal, a type of thermal detector, thus the fundamental measurement is relatively wavelength insensitive. The telescope is designed to provide data for all weather conditions during which a concentrating solar energy system would be operating. Analyses show that for a clear blue sky, the amount of radiation coming directly from the sun, while for a sky with thin clouds or haze, the circumsolar radiation is some 25% of the direct solar radiation. Under such conditions ...

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.

Energy Technology Data Exchange (ETDEWEB)

To study CdZnTe as a high energy resolution gamma ray detector with a novel new design, and to build a detector array from the new detector design

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

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 ...

International Nuclear Information System (INIS)

The principle is described of a method using low-activity emitters as the primary radiation source for analysis. The selection of the radiation source and the detection methods including the assessment of the applicability of various radiation detectors are discussed. The benefits and the constraints of the method are considered. Practical examples are presented showing the application possibilities of the method for testing the thickness of bearing layers, piston ring coats, lead layers, etc. The possibility is shown of applying the rapid test for the composition of tungsten and chromium alloyed metal materials in testing complex systems. (J.K.).

International Nuclear Information System (INIS)

The role of robotics and remote handling equipment in future nuclear power plant maintenance activities is discussed in the context of artificial intelligence applications. Special requirements manipulators, control systems, and man-machine interfaces for nuclear applications are noted. Tasks might include inspection with cameras, eddy current probes, and leak detectors; the collection of material samples; radiation monitoring; and the disassembly, repair and reassembly of a variety of system components. A robot with vision and force sensing and an intelligent control system that can access a knowledge base is schematically described. Recent advances in image interpretation systems are also discussed.

Energy Technology Data Exchange (ETDEWEB)

Manned-space missions bring an exposure due to corpuscular radiations of which nature is quite different from what we encounter in the ground environment. In the space environment, many secondaries are produced through interactions of cosmic ray primaries with the spacecraft wall and other surrounding materials. Among this large variety of radiation components in the space, the contribution of neutrons to the radiation exposure of astronauts has remained to be studied. Up to today, efforts to measure neutron dose equivalent have been made using passive detector systems. Considering uncertainties involved in current measurements and estimations of high energy neutrons, and their increasing importance for future manned missions, it is necessary to measure neutron spectrum in the spacecraft under realistic conditions. The neutron spectra have never been measured on board a spacecraft, ...

Energy Technology Data Exchange (ETDEWEB)

In the ALICE experiment at CERN, the Detector Control System (DCS) employs several interacting software components to accomplish its task of ensuring the correct operation and monitoring of the experiment. This paper describes the Front-End-Electronics Communication (FeeCommunication) software and its role within the DCS. The FeeCommunication software's central task is passing configuration and monitoring data between the top level DCS process control and the field devices of several detectors within ALICE. The lowest level of the FeeCommunication software runs on the DCS boards, specialized embedded systems which are in direct contact with the field devices and are physically located within the detector. The middle and upper layers run on standard PC hardware located in the counting room or other external locations. This paper focuses on the design and implementation of ...

International Nuclear Information System (INIS)

Full text: A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through de trending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality. (author)

Science.gov (United States)

The PLANCK SURVEYOR is a European Space Agency satellite mission to image the very faint anisotropies in the temperature of the Cosmic Microwave Background (CMB) radiation. Maynooth is actively participating in an international collaboration of scientists involved with the optical design of the High Frequency Instrument (HFI). This paper outlines research which has been undertaken in Maynooth concerned with numerical modelling of the optical characteristics of the multi-frequency array of detectors making up the HFI instrument. In the study the commercial software package ZEMAX was used to model the coupling of the focal plane HFI detectors to the PLANCK telescope. This package is particularly useful in the optical design of PLANCK because of the powerful optimisation features of the software. It is thus possible to readily determine the optimum positioning of the detectors in the focal plane of the ...

Energy Technology Data Exchange (ETDEWEB)

Handheld, backpack, and mobile sensors are elements of the Global Nuclear Detection System for the interdiction and control of illicit radiological and nuclear materials. They are used by the U.S. Department of Homeland Security (DHS) and other government agencies and organizations in various roles for border protection, law enforcement, and nonproliferation monitoring. In order to systematically document the operational performance of the common commercial off-the-shelf portable radiation detection systems, the DHS Domestic Nuclear Detection Office conducted a test and evaluation campaign conducted at the Nevada Test Site from January 18 to February 27, 2006. Named 'Anole', it was the first test of its kind in terms of technical design and test complexities. The Anole test results offer users information for selecting appropriate mission-specific portable radiation detection ...

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)

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)

In 1998, research began at Idaho National Engineering and Environmental Laboratory to investigate the application of "6Li and "7Li isotopes to the measurement of neutron and gamma radiation. Various size pairs of "6Li and "7Li 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)

International Nuclear Information System (INIS)

A possibility is considered or reducing the surface heterogeneity effect of an item being tested on the result of radiation flaw detection by means of signal delay of one of detectors in a two-channel radiometric flaw detector. The exposure of a translationally moving item has been studied as well as an external exposure of a rotating hollow item.

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.

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.

Science.gov (United States)

Jan 13, 2011 ... This 360-degree mosaic of images from the navigation camera on ... The Radiation Assessment Detector, shown prior to its September 2010 ...

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.

Energy Technology Data Exchange (ETDEWEB)

A mobile gamma-ray scanning system has been developed by Oak Ridge National Laboratory for use in the U.S. Department of Energy's remedial action survey programs. The unit consists of NaI(Tl) detectors housed in a specially equipped van. The system is operator controlled through an on-board minicomputer with data output provided on the computer video screen, strip chart recorders, and an on-line printer. Data storage is provided on floppy disk. Multichannel analysis capabilities are included for qualitative radionuclide identification. A /sup 226/Ra-specific algorithm is currently employed to identify locations containing residual radium-bearing materials.

Energy Technology Data Exchange (ETDEWEB)

Superconducting thin film particle detectors can be very attractive due to the low sensitivity to radiation damage. We describe the fabrication procedure and the characterization of Nb/Al bilayers as particle detectors. First steady and dynamical results are reported from tests of 5 MeV alpha-particle detection.

Energy Technology Data Exchange (ETDEWEB)

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)

This research focuses on the development and application of high order statistical analyses applied to measurements performed with subcritical fissile systems driven by an introduced neutron source. The signatures presented are derived from counting statistics of the introduced source and radiation detectors that observe the response of the fissile system. It is demonstrated that successively higher order counting statistics possess progressively higher sensitivity to reactivity. Consequently, these signatures are more sensitive to changes in the composition, fissile mass, and configuration of the fissile assembly. Furthermore, it is shown that these techniques are capable of distinguishing the response of the fissile system to the introduced source from its response to any internal or inherent sources. This ability combined with the enhanced sensitivity of higher order signatures ...

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 ...

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.

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...

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)

Solid state nuclear track detectors (SSNTD) record radiation in the form of tracks. In the case of high track density, however, it is not always possible to distinguish each track separately. The track density might then be underestimated unless the loss of track number due to overlapping is compensated. An elaborated 'erosion' or curve fitting process is applied usually, for the separation of the overlapping tracks, to automatic track counting systems. This paper shows a much simpler correction method which was developed by the analogy of the correction equation for the dead time of GM counters. From a set of about 10 data obtained from high track density detectors, the equation for SSNTD can be determined by a least square fitting. Once the equation is found, true track density could be derived easily without any help of complex image processing or calculation, such as the erosion or ...

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.

Energy Technology Data Exchange (ETDEWEB)

An analyser for detecting explosives has at least one neutron source and a plurality of gamma ray detectors. An article to be analysed is moved adjacent the source and detectors and is subjected to neutrons which generate gamma rays from any nitrogen in the article. The gamma rays are detected and analysed to determine the nitrogen concentration within the article. In order to achieve an area of uniform detection there are a plurality of detectors equidistant both from the or each source and from the article to be analysed. In order to avoid a decrease in sensitivity away from the source(s) and detectors there may be a second opposing array of source(s) and detectors on the opposite side of the article. For greatest uniformity of detection, a source in one array opposes a detector in the other array and vice versa. Transmission of radiation ...

International Nuclear Information System (INIS)

Acceptance testing of mammographic imaging systems technical is the first approach in order to guarantee that mammograms will be achieved with the minimum radiation dose compatible with an image quality suitable for diagnose purposes. The aim of this study is to assess the practical applicability of different protocols in acceptance test of digital mammographic systems. This study has been carried out on the results of the acceptance tests of five flat panel digital mammographic systems. Parameters established in the systems technical specifications and those evaluated in the consulted protocols were tested. Due to the fact that the legislation in our country does not demand to consider a specific protocol, the results obtained were also compared considering different existing protocols. Results show discrepancies between manufacturers limiting values and those established in the ...

International Nuclear Information System (INIS)

A prototype for a quasi-cw, and high-average power free electron laser (FEL) driven by a 15 MeV superconducting rf linac has been developed, and constructed at Tokai, JAERI since 1989. Cryogenic and accelerating fields' performances of four JAERI superconducting accelerator modules have been realized without any serious problem in the FEL accelerator vault and experimental hall. Since modification and related maintenance of the cryogenic refrigerator system for the driver were completed in the middle of October 1995, the system has run with no trouble, and the driver has been continuously run very successfully up to now. The optical resonator system and related electron beam transport system have been modified to realize larger acceptance than the old for both of the undulator radiation and energetic electron beam in 1995 Japanese fiscal year. In the modification, an alignment and ...

Energy Technology Data Exchange (ETDEWEB)

To date, no single passive detector has been found that measures dose equivalent from ionizing radiation exposure in low-Earth orbit. We have developed the I.S.S. Passive Dosimetry System (P.D.S.), utilizing a combination of TLD in the form of the self-contained Pille TLD system and stacks of CR-39 plastic nuclear track detector (P.N.T.D.) oriented in three mutually orthogonal directions, to measure total dose and dose equivalent aboard the International Space Station (I.S.S.). The Pille TLD system, consisting on an on board reader and a large number of Ca{sub 2}SO{sub 4}:Dy TLD cells, is used to measure absorbed dose. The Pille TLD cells are read out and annealed by the I.S.S. crew on orbit, such that dose information for any time period or condition, e.g. for E.V.A. or following a solar particle event, is immediately available. Near-tissue equivalent CR-39 ...

Energy Technology Data Exchange (ETDEWEB)

The US Department of Energy (DOE) sponsors an extensive research program to improve the methods, dosimeters, and instruments available to DOE facilities for measuring neutron dose and assessing its effects on the work force. The Total Dose Meter was recently developed for measuring in real time the adsorbed dose of mixed neutron and gamma radiation and for calculating the dose equivalent. The Field Neutron Spectrometer was developed to provide a portable instrument for determining neutron spectra in the workplace for flux-to-dose equivalent conversion and quality factor calculation. The Combination Thermoluminescence/Track Etch Dosimeter (TLD/TED) was developed to extend the effective neutron energy range of the conventional TLDs to improve detection of fast-energy neutrons. An Optically Stimulated Luminescence Dosimeter is presently being developed for application to gamma, neutron, and beta radiation. An Effective Dose Equivalent ...

International Nuclear Information System (INIS)

In future collider experiments, where a background radiation level is estimated to be very high, e.g. around 10"2 #approx# 10"5 Gy/yr and 10"1"1 #approx# 10"1"4 n/cm"2/yr at SSC, the detectors operating around the collision point in the experiments will encounter a considerable amount of radiation. Therefore, the detectors, especially the calorimeter, are required to be resistive against high radiation levels. From this point of view, it is of great importance to study the effects of radiation damage on the performance of the detectors. The authors report preliminary results of measurements of radiation hardness of the plastic scintillating fiber Kuraray SCSF-81 against irradiation with fast neutrons and "6"0Co #gamma#-rays in the region of the neutron fluence from 1 x 10"1"1 to 5 x 10"1"3 n/cm"2 and the integrated ...

Energy Technology Data Exchange (ETDEWEB)

A new focal plane detector for an Enge split pole spectrograph has been developed which is able to resolve individual elements and isotopes up to the mass 100 region. It consists of a 60 cm long position sensitive parallel plate avalanche counter backed by a large Bragg curve detector. Compared with other position sensitive focal plane counters the new detector system has a very good time resolution (less than 300 ps) and can be operated at much higher counting rates (up to 25 kHz). The intrinsic resolution of the position detector is less than 1 mm. In addition to the energy and the nuclear charge signal obtained from the Bragg curve detector the angle of incidence into the detector can be measured with an accuracy of better than 1/sup 0/. The detector has already been used in a variety of experiments where good timing, ...

Energy Technology Data Exchange (ETDEWEB)

The feasibility of using of current-biased superconducting strips for radiation detection is investigated. Narrow Ta strips are exposed to 5.5 MeV [alpha]-particle radiation and the rise-time of the induced voltage pulses is measured as function of temperature and bias current. The rise-time of the voltage signal strongly depends on the site on the strip which is hit by the [alpha]-particle. In order to determine the spatial resolution of a superconducting strip detector, position-sensitive measurements were performed. The maximum lateral resolution estimated so far is 25[mu]m in a 7[mu]m wide, 340 nm thick and 0.6 mm long Ta-strip. (orig.)

Energy Technology Data Exchange (ETDEWEB)

In future experiments the readout electronics for pixel detectors is required to be resistant to a very high radiation level. In this paper we report on irradiation tests performed on several preFPIX2 prototype pixel readout chips for the BTeV experiment exposed to a 200 MeV proton beam. The prototype chips have been implemented in commercial 0.25 {micro}m CMOS processes following radiation tolerant design rules. The results show that this ASIC design tolerates a large total radiation dose, and that radiation induced Single Event Effects occur at a manageable level.

Science.gov (United States)

Nov 8, 2010 ... Ihring Mission 11, the radiation dosimetry measurement system functioned normally and provided data on the Earth's trapped radiation belts ...

British Library Electronic Table of Contents (United Kingdom)

Subject of this study is the question of whether cone beam CT (CBCT) images with reduced projection data are suitable for use in adaptive radiation therapy (ART) treatment planning. For this purpose image quality and dose calculation accuracy depending on imaging modality were analysed. In this context, two CBCT-methods will be indicated having reduced projection data sets: Scans acquired with 200^o rotation angle in order to accelerate the CBCT process (half scan), or scans with an asymmetric cone beam and detector offset, used to enlarge the field-of-view (half fan). Methods: For three different CBCT-modes (On-Board-Imaging, Varian Medical Systems), two of them based on reduced projection data, and a conventional multidetector CT system, the main image quality parameters were studied. Tr...

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 ...

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)

A facility for studying photon-neutron reactions under a braking #gamma#-beam with an energy of up to 26 MeV from a betratron includes Saratov-2, SM-4A, and IBM AT-386 microcomputers. Neutron detectors, pulsed braking radiation dosimeters, and the devices to control the betatron energy are described.

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)

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)

International Nuclear Information System (INIS)

The authors are developing a high specificity detector for detecting the increased metabolic rate of breast tumors. Positron emission mammography (PEM) provides a highly efficient, high spatial resolution positron imaging system. PMT plays a very important role in PEM detectors, because most of the systems consist of scintillator arrays coupled with PMT. Our detector is composed of 20 x 20 arrays of 2 mm x 2 mm x 20 mm of Bi_4Ge_3O_1_2 (BGO) scintillators and a novel flat panel position-sensitive PMT (FP-PS-PMT)-Hamamatsu R8400-00-M256. Spatial resolutions of 2.0 mm FWHW and energy resolutions of 23% FWHM are achieved. (authors)

Energy Technology Data Exchange (ETDEWEB)

APEX (ATLAS Positron EXperiment), a collaborative effort of ANL, FSU, MSU/NSCL, Princeton, Queen`s, Rochester, Washington and Yale, is an experiment to study positron and electron production in very heavy ion collisions. The electrons and positrons are detected with two detector arrays, each consisting of 216 1 mm thick Si PIN diodes, and their energy and time-of-flight are measured. The number of detectors and limited space made it necessary to develop a system that could efficiently process and transfer signals from the detectors to the charge sensing ADC`s and data readout electronics as well as monitor the condition of the detectors. The discussion will cover the electronics designed for the Si detectors, including the charge amplifier, ``Mother board`` for the charge amplifiers, 8 channel Shaper, 16 channel Constant Fraction Discriminator (CFD), 16 channel ...

International Nuclear Information System (INIS)

The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest PET/MRI developments use solid-state light detectors that can be operated even at high magnetic fields. Initial pilot studies with prototype animal PET/MRI ...

UK PubMed Central (United Kingdom)

Objective. For the multislice CT (MSCT) systems with a larger number of detector rows, it is essential to employ dose-reduction techniques. As...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

High-purity and doped GaAs films have been grown by Liquid-phase epitaxy (LPE) for development of a blocked impurity band (BIB) detector for far-infrared radiation. The film growth process developed has resulted in the capability to grow GaAs with a net active impurity concentration below 1 x 10{sup 13} cm{sup -3}, ideal for the blocking layer of the BIB detector. The growth of n-type LPE GaAs films with donor concentrations below the metal-insulator transition, as required for the absorbing layer of a BIB detector, has been achieved. The control of the donor concentration, however, was found to be insufficient for detector production. The growth by LPE of a high-purity film onto a commercially grown vapor-phase epitaxial (VPE) n-type GaAs doped absorbing layer resulted in a BIB device that showed a significant reduction in the low-temperature dark current compared to the absorbing ...

Energy Technology Data Exchange (ETDEWEB)

Characteristics of lead-zirconate-titanate (PZT) elements were studied by directly irradiating them with a 400 MeV/n Xe beam. The elements were sensitive to 10{sup 4} Xe ions and their output amplitudes were proportional to the beam intensity. An ensemble of those output amplitudes displayed a Bragg-curve-like response towards the range of 400 MeV/n Xe ion. We discuss the potential of PZT elements as a radiation detector and their application to high-intensity and high-energy detectors. (author)

Energy Technology Data Exchange (ETDEWEB)

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

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 miniature device is described for measuring integral potential alpha energy concentration of radon daughter products (Csub(Rn)) for personnel and stationary dosimetry. The measuring apparatus consists of an air sampler, filters and TLD detectors. CaSO_4:Dy-teflon pellets were used as the detectors which registrate #gamma# radiation as well. The TLD-effect dependence on the potential alpha energy, as well as the fading of the detectors at 20-60 deg C after 170 hrs operation are presentd. The fading up to 40 deg C has been found to be negligible. The dosimeter may be used to measure Csub(Rh) starting with the 10"5 MeVxh/1 threshold, the accuracy being not worse than +-30%.

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).

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. ...

International Nuclear Information System (INIS)

Instrumental neutron activation analysis (INAA) and radionuclide X-ray fluorescence analysis (RXFA) were used for the determination of rare earth elements. For INAA, solution obtained by sample decomposition was dripped onto filter paper, enclosed and sealed into a polyethylene foil. The sample was activated in reactor WWR-S over a period of 4 to 6 hours with a neutron fluence of 10"1"3cm"-"2. Gamma radiation measurement was carried out with a planar and a coaxial HP-Ge detector in three decay periods. La, Ce, Nd, Sm, Eu, Gd, Tb, Ho, Tm, Yb and Lu were determined. The advantage of the method is its accuracy and high sensitivity, the disadvantage is the time-consuming analysis. The RXFA method was used as a rapid and operative method for the analysis of loose ore samples, aqueous and organic solutions of rare earth elements. For exciting X-ray radiation, "2"4"1Am was used and the radiation of K-lines was ...

Energy Technology Data Exchange (ETDEWEB)

In order to judge the potential fluorescent lamp applications of various low-pressure positive column discharges it is necessary to measure the absolute power emitted in the ultraviolet region of the spectrum. For rare-gas discharges the principle emission occurs in the vacuum ultraviolet so that it is difficult to measure the radiant emittance (power per unit area) of the resonance radiation by standard methods. Two independent techniques are discussed for measuring the radiant emittance of positive column discharges in the vacuum ultraviolet. These techniques are used to study xenon positive column discharges at the resonance wavelength of 147 nm. The first method relies on the measurement of the resonance level density by absorption techniques. The effective decay rate of the resonance level is then determined by the simulation of resonance radiation transport. These two quantities are combined to yield the radiant emittance at 147 nm ...

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)

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)

We report on the activities of the High Energy Physics Group at the University of Texas at Arlington for the period 1994-95. We propose the continuation of the research program for 1996-98 with strong participation in the detector upgrade and physics analysis work for the D0 Experiment at Fermilab, prototyping and pre-production studies for the muon and calorimeter systems for the ATLAS Experiment at CERN, and detector development and simulation studies for the PP2PP Experiment at Brookhaven.

International Nuclear Information System (INIS)

We describe the early stage of development of an engineering model portable, real-time neutron spectrometer. Several systems of two distinct detector types, a helium 3 gas filled proportional counter and a bulk silicon solid state detector, will be necessary to cover the energy range from thermal to 500 MeV. The advantages and disadvantages of using a moderator were investigated experimentally.

Energy Technology Data Exchange (ETDEWEB)

A focal plane detector system consisting of a vertical drift chamber, parallel plate avalanche counters, and an ionization chamber with segmented anodes has been installed in the Broad Range Spectrometer at the Holifield Facility at Oak Ridge. The system, which has been designed for use with light-heavy ions with energies ranging from 10 to 25 MeV/amu, has a position resolution of approx. 0.1 mm, a scattering angle resolution of approx. 3 mrad, and a mass resolution of approx. 1/60.

International Nuclear Information System (INIS)

Purpose: To prevent structure material meltdown upon rupture of cooling pipeways in a impurity remover by preventing the coolants from flowing into the vacuum vessel while continuing the supply of coolants to other portions to be cooled. Constitution: Dual cooling pipeway systems are disposed to the neutralizing plates of the impurity remover. A rupture detector (pressure gage) is mounted to each of the cooling pipeways and flow rate control valves to be opened and closed by the signal from the detector are disposed to the upstream and downstream of the cooling pipeway. In this constitution if the cooling pipes should be ruptured, the coolant supply is stopped to the ruptured system in which the flow rate valve is closed by the signal from the rupture detector. However, since the coolant is kept to be supplied to the other system of the cooling pipeways, ...

International Nuclear Information System (INIS)

Correlation characteristics of quantum noise on the shadow radiation image (RI) of the object under nondestructive testing are studied. Mathematical model of RI occasional distortions is derived. The model takes into account the parameters of object under testing and of radiation beam by radiation quanta flux density. The results obtained can be used as a component in the process of investigation of various radiation testing systems

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 ...

International Nuclear Information System (INIS)

The physical foundations are described of radionuclide X-ray fluorescence analysis (RXFA) and the table shows the values of K- and L-absorption thresholds and the K- and L-line energies of elements. The calculation of the intensity of characteristic radiation during RXFA proceeds from relations derived for conventional X-ray fluorescence analysis. The choice of the radionuclide source is ruled by the nature of the analysed substance and the used detection technique. The diagram shows the areas of radionuclide sources and the energy of the fluorescence radiation of elements. The table shows the spectra of radionuclide sources suitable for the purposes of RXFA measured by semiconductor Si(Li) and Ge(Li) detectors. (ES).

International Nuclear Information System (INIS)

A complete heavy ion identification system in heavy ion reaction studies consists, in general, of: 1) a position sensitive avalanche counter, and 2) ionization chamber to obtain total energy as well as a heavy ion identifier signal (such as the E#DELTA#E signal from a E-#DELTA#E type detector or the height of the Bragg peak that scales as Z of the heavy ion in a Bragg curve ionization chamber). In addition, a time-of-flight information may be needed to resolve the masses of the ions. With this motivation in mind, a composite detector system consisting of a Bragg curve spectroscopy ionization chamber (BCS-IC) and a one dimensional position sensitive parallel grid avalanche counter (XPS-PGAC) has been developed and used successfully at the BARC-TIFR pelletron accelerator facility. The design and performance of this gas detector system are reported. (author). 4 ...

Energy Technology Data Exchange (ETDEWEB)

The Feynmann and other fluctuation techniques have been shown to be useful for determining the multiplication of subcritical systems. The moments of the counting distribution from neutron detectors is analyzed to yield the multiplication value. We present the methodology and some selected applications and results and comparisons with Monte Carlo calculations.

International Nuclear Information System (INIS)

The introduction of tolerance to radiation (''radiation-hardness'') into large electronic systems is one of the major tasks to which this Handbook will be put. The practices recommended here for inculcating radiation-tolerance in equipment require advanced physical modeling techniques, precise engineering procedures, and firm assurance procedures. The degree to which these procedures should be used in an equipment project can be measured by the severity of the raw radiation environment, the desired reliability of the system, and the requirement of that project for radiation-sensitive technologies. The balance of device/circuit design versus shielding will depend on whether the radiation is highly penetrating -- as in isotope handling or military environments -- or readily attenuated, as in space. In this chapter the ...

Energy Technology Data Exchange (ETDEWEB)

The cosmic antiparticle ring imaging Cherenkov experiment (CAPRICE) flew on a stratospheric balloon 8-9 August 1994 over northern Canada and collected data for more than 21 hours with less than 5 g/cm{sup 2} of residual atmosphere. The instrument includes a solid radiator RICH detector and an electromagnetic calorimeter for particle identification in the magnetic spectrometer. Preliminary antiproton and positron identification capabilities are presented.

Energy Technology Data Exchange (ETDEWEB)

Compton scatter tomography utilizes the electronic collimation characteristics available through the Compton scattering angle-energy correlation to obtain tomographic images. In this work we present particular aspects of the technique, which are relevant to the inverse radiation transport problem of reducing marginal projection data to radial two-phase flow regime maps. The results indicate a viable technique for the tomographic imaging of tow-phase flow using practical source strengths and reasonably few detectors.

Energy Technology Data Exchange (ETDEWEB)

The multicell proportional chambers at the backing calorimeter of the ZEUS experiment at the storage ring HERA are supplied with a gas mixture of Ar/CO[sub 2] by an open gas system. Flow proportional counters with the build-up [sup 55]Fe sources are used as gas system monitoring detectors. The ZEUS experiment is planned to collect data for about 10 years. Therefore, the lifetime of the Ar/CO[sub 2] mixture should be known. In this paper, the results of laboratory tests and preliminary measurements of the aging effects for monitoring counters are presented. ((orig.))

Science.gov (United States)

SPONTANEOUS RADIATION EMITTED BY MOVING TETHERED SYSTEMS. M. Dobrowolny. Istituto Fislca Spazio Interplanetario, CNR Italy ...

Energy Technology Data Exchange (ETDEWEB)

The importance of radiation management for nuclear facilities including nuclear power plants has increased as the general public understanding has progressed, and necessary information for management must be processed exactly and quickly. In nuclear power plants, radiation management is performed by each individual operation, and collected information is managed by the system of each operation. The distributed-processing radiation management system has been developed aiming to use a general-purpose LAN and make quick and efficient use of information managed by individual operations. This paper describes the system configuration and functions. (author)

International Nuclear Information System (INIS)

Proceeding from analysis of the influence of parameters of the target-filter system on radiation-physical characteristics of braking radiation, some recommendations were issued for assessment of the forming systems of medical accelerators of electrons. A new criterion - a coefficient of the forming system efficacy - was introduced, characterizing a beam formation tract with relation to a whole set of radiotherapeutic problems.

International Nuclear Information System (INIS)

Scattered radiation generated in patient and imaging system has to be considered when quality-assurance tests involve dose detection or image-quality estimations. Measurement of automatic-exposure control dose can be altered by backscattering from intensifying screens of more than 10% and the equipment transmission factor can be overestimated up to a factor of 10 when only primary radiation is used. The sensitivity of intensifying screens depends on the angle of incidence of the radiation and so primary and scattered radiation are detected differently. The quality-control aspects of anti-scatter grids are discussed. (author).

International Nuclear Information System (INIS)

Remote-controlled handling systems are required for work to be done in the decommissioning and dismantling of nuclear facilities. These systems are equipped with electronic devices suitable for use in working environments affected by ionizing radiation. The publication explains the step-wise progress achieved for improving the radiation resistance of electronic devices with the example of a four-quadrant controlling device for the motors of a manipulator. The radiation resistance of the device could be enhanced to radiation energies of 5.500 Gy. This means that a manipulator vehicle equipped with this controlling device can take up to approx. 15 kGy all in all, taking into account its own shielding properties. (DG).

Energy Technology Data Exchange (ETDEWEB)

This report describes development of an electronic system designed to reduce vibration generated by a cryocooler. The diminished vibration makes it practical to use the active cooler to extract heat from a portable gamma ray detector instrument. The system was developed for a Sunpower cryocooler with an integrated counterbalance mass. The overall momentum cancellation approach is also applicable to other similar cryocoolers. The cancellation system is an assembly of several components tailored to accomplish the required vibration reduction with minimum power consumption and volume. It is designed to be powered by a 18--32 Volt battery. Up to ten harmonics of the 58.65 Hz drive frequency are controlled. In addition to the vibration cancellation, the electronic system produces the drive signal for the cryocooler and regulates the cooler temperature. The system ...

International Nuclear Information System (INIS)

The total radiation rate, angular distribution of the emitted energy and photon correlations of the cooperative spontaneous radiation from two atoms with different resonance frequencies and spontaneous decay rates are calculated. Contrary to the case of two identical atoms oscillations appear in the total radiation rate and the spatial distribution of the total number of emitted photons differs from the single-atom radiation pattern. The effect of the dipole-dipole near-field interaction on the time evolution of the atomic system is discussed. (author).

Energy Technology Data Exchange (ETDEWEB)

This study presents results from Monte Carlo radiation transport calculations aimed at characterizing a novel methodology being developed to detect partial defects in Pressurized Water Reactor (PWR) spent fuel assemblies (SFAs). The methodology uses a combination of measured neutron and gamma fields inside a spent fuel assembly in an in-situ condition where no movement of the fuel assembly is required. Previous studies performed on single isolated assemblies resulted in a unique base signature that would change when some of the fuel in the assembly is replaced with dummy fuel. These studies indicate that this signature is still valid in the in-situ condition enhancing the prospect of building a practical tool, Partial Defect Detector (PDET), which can be used in the field for partial defect detection.

International Nuclear Information System (INIS)

The whole equipment consists of three separate portable parts: a detector case, a microprocessor and a graphic TV monitor. Magnetic tape memory and an x-y recorder can be connected for recording the measured spectra. The analyzer contains two built-in exchangeable excitation radionuclides. Fluorescence and scattered radiation is detected using a proportional detector. The detected pulses are analyzed by a 256-channel analyzer and the results are shown on the display. The device may be used in mining laboratories, coal and ore dressing plant control rooms or in mining fields of open cast mines for quick detection of the quality of mined or dressed raw materials. (E.S.). 1 fig.

Energy Technology Data Exchange (ETDEWEB)

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 ...

CERN Document Server

Convexity/concavity properties of symbol error rates (SER) of the maximum likelihood detector operating in the AWGN channel (non-fading and fading) are studied. Generic conditions are identified under which the SER is a convex/concave function of the SNR. Universal bounds for the SER 1st and 2nd derivatives are obtained, which hold for arbitrary constellations and are tight for some of them. Applications of the results are discussed, which include optimum power allocation in spatial multiplexing systems, optimum power/time sharing to decrease or increase (jamming problem) error rate, and implication for fading channels.

International Nuclear Information System (INIS)

This paper describes the design of PMT readout module for detector prototype of Daya Bay Reactor Neutrino Experiment. According to the design requirements of the readout module, the basic structure of the readout module is discussed. This paper also discusses how to realize the charge measurement and time measurement and data processing using a high performance FPGA. The DAQ system including three readout modules and one trigger module are well commissioned and doing data taking now. (authors)

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

We present the latest developments for the radiation laboratory curriculum at the Department of Physics and Astronomy of Western Kentucky University. During the last decade, the Applied Physics Institute (API) at WKU accumulated various equipment for radiation experimentation. This includes various neutron sources (computer controlled d-t and d-d neutron generators, and isotopic 252 Cf and PuBe sources), the set of gamma sources with various intensities, gamma detectors with various energy resolutions (NaI, BGO, GSO, LaBr and HPGe) and the 2.5-MeV Van de Graaff particle accelerator. XRF and XRD apparatuses are also available for students and members at the API. This equipment is currently used in numerous scientific and teaching activities. Members of the API also developed a set of laboratory activities for undergraduate students taking classes from the physics curriculum (Nuclear Physics, Atomic Physics, and ...

Energy Technology Data Exchange (ETDEWEB)

The diffusion coefficient of particles in radioactive gases has been calculated with account of random wandering of aerosols (occurrence of local fields affecting the particles; recoils accompanying radiation emitted by particles, etc.). To determine the diffusion coefficient, the method of Fokker-Planck equation derivation was used. A formula is presented for calculating the radiation-stimulated diffusion coefficient. A linear growth of the diffusion coefficient with radioactivity is noted according to the formula, the diffusion coefficient is mainly determined by the field in the radiation damage region. The aerosol radioactivity may result in a more rapid deposition of aerosols in the pipelines and aerosol purification systems. The diffusion rate grows not only in the presence of intrinsic radioactivity but in case of external radiation exposure as well.

UK PubMed Central (United Kingdom)

To capitalize on the response of tumor cells to ionizing radiation, we developed a controlled-release nanoparticle drug delivery system using a targeting peptide that recognizes a radiation-induced...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

The Monte Carlo ray-tracing method is applied and coupled with optical properties to predict the radiation performance of solar concentrator/cavity receiver systems. Several different cavity geometries are compared on the radiation performance. A flux density distribution measurement system for dish parabolic concentrators is developed. The contours of the flux distribution for target placements at different distances from the dish vertex of a solar concentrator are taken by using an indirect method with a Lambert and a charge coupled device (CCD) camera. Further, the measured flux distributions are compared with a Monte Carlo-predicted distribution. The results can be a valuable reference for the design and assemblage of the solar collector system.

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.)

International Nuclear Information System (INIS)

A consideration is given to the problem of selecting optimized methods of radionuclide radiation registration during the control of the objects with essential changes in thickness. Adequate model of information signal formation is developed and analyzed for the case of the existence of an inertial link of the system with the dead time of a noncontinued type. The boundary values of radiation thickness and radiation flux intensity that divide the priority of using either digital or analog registration modes are revealed. The method is found for the full correction of a systematic error of flux intensity measurement because of the dead time of the apparatus. To control the objects with essential variation of thickness the method of selective measurement of radiation intensity is proposed

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 ...

Energy Technology Data Exchange (ETDEWEB)

The effect that different chemical and physical atomic environments can have on the relative intensities of radiative electron transitions from the filling of K shell vacancies was investigated. The method used involved the detection of photoionization induced X-ray fluorescence. An experimental system based on a hyper pure germanium detector (HPGE) was used to measure the relative K-L and K-M X-ray yields from the photofluorescence of a series of lanthanide elements and compounds. A background subtraction and peak integration strategy was employed which accounted for scattering in the samples and scattering of the flux from the radioisotope photoionization sources. Analysis of the data resulted in a tabulation of relative K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios. The measured relative K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios were compared to the calculated values predicted by the ...

International Nuclear Information System (INIS)

Advanced modality of high-precision radiotherapy fulfilled by a composition of large numbers of small field beams called 'beamlets' can be achieved via nonuniform intensity fluencies. In case of radiation measurements and calculations with narrow high-energy photon beams, however, an accurate two-dimensional dosimetry is a challenging task due to dosimetrically unfavorable phenomena such as dramatic changes of the dose at the field boundaries, dis-equilibrium of the electrons resulting from larger detector volume, and non-uniformity between the detector and the phantom materials. Meanwhile, with the advantages of high spatial resolution and wide range of absorbed doses, there is a growing demand of GAFCHROMICat..EBT film to confirm delivered dose distribution. Especially, the effects from the material differences between the phantom and the film can be minimized in the heterogeneous condition since the GAFCHROMICat..EBT ...

Energy Technology Data Exchange (ETDEWEB)

Three types of drift chambers are being constructed for the Fermilab D/O/ experiment. The construction and readout of these chambers stress good spatial resolution, good two hit separation, and dE/dx. A 106 MHz FADC system with hardware zero suppression is being constructed to readout this system. 8 refs., 12 figs., 1 tab.

CERN Document Server

CZT Detector and HXI Development at CASS/UCSD

International Nuclear Information System (INIS)

X-ray fluorescence analysis was used to determine the zinc content of the ''Perilacin'' powder and the ZnO content of the ''Epiderman-pix'' powder. The characteristic Ksub(#alpha#) line of zinc was excited using a "1"4"7Pm/Mo source (10"7 s"-"1) and the molybdenum Ksub(#alpha#) line (17.47 keV). 4 to 5% Zn and 45 to 49% ZnO were determined with a NaI(Tl) scintillation detector. The radiation intensity was found to decrease with particle size. (M.K.).

Science.gov (United States)

Neutron resonance interactions with /sup 100/Mo were studied at a time-of-flight facility. The transmission of two oxide samples (97.4% /sup 100/Mo) was measured at a 78.20 m flight path and the neutron capture cross section was measured at 40.12 m. Resonance analyses yielded parameters of 124 resonances. Capture ..gamma..-ray spectra from 11 resolved resonances were measured with a Ge(Li) detector at a 10.45 m flight path. In contrast to neighboring nuclei, partial radiation widths of strong p-wave resonances are not in agreement with valence model predictions.

Energy Technology Data Exchange (ETDEWEB)

Alpha particle confinement is necessary for ignition of a D-T tokamak fusion plasma and for first wall protection. Due to high radiation backgrounds and temperatures, scintillators and semiconductor detectors may not be used to study alpha particles which are lost to the first wall during the D-T programs on JET and ITER. An alternative method of charged particle spectrometry capable of operation in these harsh environments, is proposed: it consists of thin foils of electrically isolated conductors with the flux of alpha particles determined by the positive current flowing from the foils. 2 refs., 3 figs.

International Nuclear Information System (INIS)

Plans, engineering parameters, and some test results for several FFTF core and primary sodium circuit instrument systems are presented. The systems discussed include temperature, flow, pressure, leak detectors, level sensors, fuel failure monitoring, sodium impurity analysis and cover gas monitors. Since many of these instruments are similar to those used in other fast reactors around the world, only a brief description is presented for these systems. Results of recent demonstration tests of the FFTF Under-Sodium Viewing and Ranging system are also presented. (U.K.).

International Nuclear Information System (INIS)

Full text: Measurement of K_#beta# to K_#alpha# x-ray intensity ratios are important not only in the field of atomic physics, radiation physics and medical physics, but also to test the validity of assumptions made in the theoretical prediction. The intensity ratios can also give information on the effect of physical and chemical environment of the element in the compound. Many investigators have adopted a single and double reflection geometries to measure the K_#beta# to K_#alpha# x ray intensity ratios to understand the effect of physical and chemical environment on x-ray fluorescence. The targets are excited by a radioactive source of having activity of the order 100 MBq. in order to carry out accurate measurement K_#beta# to K_#alpha# x-ray intensity ratios, we have develop 2#pi# geometrical configuration method : placing a target right on the surface of the detector facing the target to measure the K shell fluorescence parameters such as ...

Energy Technology Data Exchange (ETDEWEB)

The subcriticality of two interacting solution tanks was determined using /sup 252/Cf-source-driven neutron noise analysis methods. These experiments were the first test of this method for an interacting system with materials (in this case, uranyl nitrate) typical of nuclear materials in processing plants. The experiments were performed to test the conclusions from previous interaction experiments with uranium metal discs for a fissile system with moderation, and to provide data to test theoretical models for coupled systems. The uranium metal experiments showed that the subcritical neutron multiplication factor, k/sub eff/, could be determined using point kinetics without any correction for spatial effects from measurements with the source and detectors located adjacent to the same cylinder, whereas for source-detector configurations with either the source and/or ...

Science.gov (United States)

instrument is shown in Figure 4-9 The incoming radiation is focused onto ...... An early rocket-borne ultraviolet spectrometer of the Ebert type by ...

Energy Technology Data Exchange (ETDEWEB)

Stochastic models for the simulation of global radiation are discussed. Thermal transients in the ground are analyzed. The performance of buried-pipe storage and a space heating system with long-term storage is described.

Energy Technology Data Exchange (ETDEWEB)

Region Lombardia has carried out a radon gas monitoring survey on its territory to localize radon prone areas as by law 241/00 enacted. To plan the survey, the Lombardia territory has been divided into two different types according to the morphology as well as the presence of a substratum of rock. The area with hills and mountains has been investigated with more attention compared to the plain because we can assume higher variability in radon concentration distribution due to the geological and morphological characteristics. The territory subdivision was based on the standard grid.. of the techniregional cartography (8 x 5 km). To perform radon indoor concentration measurements about 3600 measuring points were selected. They are located at the ground floor of buildings with the characteristics to ensure the tests are representative and comparable. It has also been taken into account evaluations done with previous surveys in accordance with the defined specification of the sites. The ...

International Nuclear Information System (INIS)

For comparison of radiation exposure and risk in different diagnostic procedures for adults and children dose measurements and calculations of organs with special risk were carried out. Parameters of image formation influencing image quality as well as of exposure concerning infants and children are recorded and discussed as to radiation exposure and protection. Conclusions are drawn with respect to systems of image formation and to standards of examination and quality assurance.

Energy Technology Data Exchange (ETDEWEB)

This paper reports the study results on the standard weather data necessary for simulation of PV power generation systems in fiscal 1994. In the study on the selection criterion of the standard weather data from the viewpoint of PV power generation systems, three typical years are used; a year with average solar radiation, and two years with extremely less and more solar radiation for safe simulation. The standard weather data are arranged for output calculation of PV power generation systems by selecting the most typical year based on long-term observation data. The data to be arranged are as follows; total, direct and scattered solar radiations incident upon a horizontal surface, solar radiation upon a slope surface, sunshine duration, air temperature, wind direction, wind velocity, amount of precipitation, and snow depth. For arrangement ...

International Nuclear Information System (INIS)

Alanine/EPR Dosimetry system is classified as a reference-standard dosimeter which used to calibrate radiation environments and to calibrate routine dosimeters in absorbed dose range of 1 to 105 Gy. Characteristics of Alanine/EPR dosimetry system are better suitable than routinely used personnel dosimeters for the long term radiation measurement in harsh condition of Nuclear power plant : This system is not significantly affected by temperature and humidity and also has low fading rate. About 1 year ago, Alanine and Lithium compound dosimeters were installed at Wolsung unit 1 for the environment monitoring as a part of equipment qualification program. 35 positions which are most severe and representative cable positions were chosen for radiation and temperature monitoring. The recovered alanine dosimeter in the period of maintenance was measured by E-scan ...

International Nuclear Information System (INIS)

The Y2K problem may impact on nuclear installations in a number of ways because embedded systems are used in nuclear routine operation, monitoring and control system. The very simplest embedded systems are capable of performing only a single function or set of functions to meet a single predetermined purpose. In more complex systems the functioning of the embedded system is determined by an application program that enables the embedded system to be used for a particular purpose in a specific application. The simplest devices consist of a single microprocessor which may itself be packaged with other chips in a hybrid system or Application Specific Integrated Circuit (ASIC). Its input comes from a detector or sensor and its output goes to a switch or activator which may start or stop the operation of a positioning motors ...

Energy Technology Data Exchange (ETDEWEB)

The Idaho Explosives Detection System was developed at the Idaho National Laboratory (INL) to respond to threats imposed by delivery trucks potentially carrying explosives into military bases. A full-scale prototype system has been built and is currently undergoing testing. The system consists of two racks, one on each side of a subject vehicle. Each rack includes a neutron generator and an array of NaI detectors. The two neutron generators are pulsed and synchronized. A laptop computer controls the entire system. The control software is easily operable by minimally trained staff. The system was developed to detect explosives in a medium size truck within a 5-min measurement time. System performance was successfully demonstrated with explosives at the INL in June 2004 and at Andrews Air Force Base in July 2004.

Energy Technology Data Exchange (ETDEWEB)

Many assays for oncogenic transformation have been developed ranging from those in established rodent cell lines where morphological alteration is scored, to those in human cells growing in nude mice where tumor invasiveness is scored. In general, systems that are most quantitaive are also the least relevant in terms of human carcinogenesis and human risk estimation. The development of cell culture systems has made it possible to assess at the cellular level the oncogenic potential of a variety of chemical, physical and viral agents. Cell culture systems afford the opportunity to identify factors and conditions that may prevent or enhance cellular transformation by radiation and chemicals. Permissive and protective factors in radiation-induced transformation include thyroid hormone and the tumor promoter TPA that increase the transformation incidence for a given dose of ...

International Nuclear Information System (INIS)

Tarapur Atomic Power Station Unit-4 is first 540 MWe pressurized heavy water reactor in India. It achieved criticality on 06th March 2005 and then operated at full power i.e 500 MWe. Radiation workers during the normal operation and reactor shutdown are exposed to radiation field. The control of dose rates and the collective dose of the radiation workers is most important for the best performance of the reactor. Experience gained during the operation of the 220 MWe reactors has shown that the Moderator system, primary heat transport system, annulus gas system and moderator cover gas system are the main systems contributing to the dose rate and collective dose. In order to identify the radio nuclides contributing to the radiation field, study was undertaken at TAPS Unit-4. Various samples from the ...

Energy Technology Data Exchange (ETDEWEB)

We measured and evaluated digital, pre-sampling and overall imaging properties (characteristic curve, modulation transfer function (MTF), Wiener spectrum (WS), noise equivalent quanta (NEQ)) for Cannon's flat-panel detector (FPD), Fuji computed radiography (FCR) and screen-film (S/F) systems, respectively. First, the digital and overall characteristic curves of FPD and FCR systems were more wide dynamic range than that of the S/F system. Second, the pre-sampling and overall MTF of FPD system were better than those of FCR system a little at lower spatial frequencies than 0.8 mm{sup -1}, but the overall MTF of FPD and FCR systems were worse than that of S/F system a little at all spatial frequencies. Third, the digital and overall WS of FPD system were similar or better than those of FCR ...

CERN Document Server

Low noise, high resolution and high dose efficiency are the common requirements for most X-ray imaging applications. Especially in medical applications the dose efficiency is a necessity for detector systems. We present the imaging performance of the Medipix2 readout chip bump bonded to a 300 mu m thick Si detector as a function of the detection threshold, a free parameter not available in conventional integrating imaging systems. Spatial resolution has been measured using the modulation transfer function (MTF) and it varies between 8.2 Ip/mm and 11.0 Ip/mm at 70%. An associated measurement of noise power spectrum (NPS) permits us to derive the detective quantum efficiency (DQE) which can be as a high as 25.5 % for a broadband incoming spectrum. The influence of charge diffusion in the sensor together with threshold variation in the readout chip is discussed. Although the Medipix2 ...

Energy Technology Data Exchange (ETDEWEB)

In embodiments, spectroscopic monitor monitors modulated light signals to detect low levels of contaminants and other compounds in the presence of background interference. The monitor uses a spectrometer that includes a transmissive modulator capable of causing different frequency ranges to move onto and off of the detector. The different ranges can include those with the desired signal and those selected to subtract background contributions from those with the desired signal. Embodiments of the system are particularly useful for monitoring metal concentrations in combustion effluent.

Energy Technology Data Exchange (ETDEWEB)

We describe a global closed orbit feedback experiment, based upon a real time harmonic analysis of both the orbit movement and the correction magnetic fields. The feedback forces the coefficients of a few harmonics near the betatron tune to vanish, and significantly improves the global orbit stability. We present the results of the experiment in the UV ring using 4 detectors and 4 trims, in which maximum observed displacement was reduced by a factor of between 3 and 4. 4 refs., 3 figs.

Energy Technology Data Exchange (ETDEWEB)

Quantitative digital imaging, using planar laser light scattering techniques is being developed for the analysis of turbulent and reacting flows. Quantitative image data, implying both a direct relation to flowfield variables as well as sufficient signal and spatial dynamic range, can be readily processed to yield two-dimensional distributions of flowfield scalars and in turn two-dimensional images of gradients and turbulence scales. Much of the development of imaging techniques to date has concentrated on understanding the requisite molecular spectroscopy and collision dynamics to be able to determine how flowfield variable information is encoded into the measured signal. From this standpoint the image is seen as a collection of single point measurements. The present effort aims at realizing necessary improvements in signal and spatial dynamic range, signal-to-noise ratio and spatial resolution in the imaging system as well as developing excitation/detection ...

Energy Technology Data Exchange (ETDEWEB)

Experimental results of ageing effects in proportional counters are presented. The measurements were carried out for 158 ZEUS-BAC gas system monitoring counters. Deterioration of the pulse height distribution in azimuth and along the anode wire are presented. The influence of water admixture on counting gas is also described. (orig.).

International Nuclear Information System (INIS)

During Phase 2 of our study of the CIXS conceptual design we have tackled additional important issues that are unique to the ITER environment. These include the thermal control of the crystal and detector enclosures located in an environment with a 100-250 C ambient temperature, tritium containment, and the range of crystal and detector movement based on the need for spectral adjustments and the desire to make measurements of colder plasmas. In addressing these issues we have selected a ''Dewar''-type enclosure for the crystals and detectors. Applying realistic view factors for radiant heat and making allowance for conduction we have made engineering studies of this enclosure and showed that the cooling requirements can be solved and the temperature can be kept sufficiently constant without compromising the specification parameters of the CIXS. We have chosen a minimum 3 mm combined thickness of the six beryllium windows ...

International Nuclear Information System (INIS)

We developed a new TLD array for precise dose measurement and verification of the spatial dose distribution in small radiation targets. It consists of a hemicylindrical, tissue-equivalent rod made of polystyrene with 17 parallel moulds for an exact positioning of each TLD. The spatial resolution of the TLD array was evaluated using the Leskell spherical phantom. Dose planning was performed with KULA 4.4 under stereotactic conditions on axial CT images. In the Leksell gamma unit the TLD array was irradiated with a maximal dose of 10 Gy with an unplugged 14 mm collimator. The doses delivered to the TLDs were rechecked by diode detector and film dosimetry and compared to the computer-generated dose profile. We found excellent agreement of our measured values, even at the critical penumbra decline. For the 14 mm and 18 mm collimator and for the 11 mm collimator combination we compared the measured and calculated data at full width at half maximum. ...

International Nuclear Information System (INIS)

The results of studies of radiation-thermocatalytic water decomposition in the 673-773 K temperature range in the presence of BeO and titanium Y-type zeolite are presented. It is found that radiation-thermocatalytic processes of hydrogen production from water are characterized by a lower activation energy (55.4 kJ/mole) as compared with thermocatalytic processes (88.4 kJ/mole). The radiation-thermocatalytic process rate in the presence of oxide systems is not an additive sum of rates of radiation-catalytic (at 296-300 K) and thermocatalytic processes of water decomposition. On the basis of obtained results the conclusion is made that during radiation-catalytic decomposition of water in a heterogeneous system BeO + H_2O the main contribution into this process is made by excitons, radiation-chemical yields of excitons and ...

Energy Technology Data Exchange (ETDEWEB)

Attention was focused on the fission process in light nuclear systems. A model calculation based on the transition-state model of nuclear fission was applied to {sup 47}V fission as populated through multiple entrance channels and to fusion-fission cross sections for production of {sup 28}Al through three different entrance channels. Angular distributions are shown for different mass channels of the {sup 29}Si+{sup 27}Al reaction at E{sub lab} = 125 MeV. Pronounced structure is seen in the symmetric and near-symmetric fission channels from the {sup 24}Mg+{sup 24}Mg reaction; cross sections for binary fragment emission are shown for E{sub lab} = 90 MeV. A large Bragg-curve detector was used in this experiment. Ways to optimize detector response were studied; in addition, the Bragg detector was instrumented with an internal position-sensitive multiwire proportional counter.

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*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 ...

International Nuclear Information System (INIS)

Complete calculations of the accelerator related background in the muon spectrometer of the CMS detector at the Large Hadron Collider are presented. The simulations have been performed with the STRUCT multi-turn tracking code and the MARS and FLUKA cascade codes taking into account latest information of the LHC lattice, vacuum conditions, beam cleaning system and the shielding and layout of the CMS experiment. Beam loss distributions in the interaction regions and their vicinities and their contribution to the background levels in the muon spectrometer of CMS are analyzed. The studies show that hadronic and electromagnetic components of machine background are efficiently suppressed by the proposed CMS shielding. High energy muons penetrate through the shielding, but in positions of significance they do not contribute more than a few percent compared to the background generated by the pp-collisions. It is anticipated that the relative ...

Energy Technology Data Exchange (ETDEWEB)

Inhalation of radon and its daughter products makes the major contribution to the total exposure of the population to natural radiations. In implementing a complex ecological survey, concentrations of radon and its daughter products were measured in different regions of Russia, namely, in the St. Petersburg Region, the Central Territories and the Altay Territory. Two suitable low price versions of the dosemeters for measuring environmental radon concentrations based on track-etch and activated-charcoal detectors were used. The radon daughter product activity and the effective dose equivalents were calculated with an equilibrium factor of 0.5 and a recommended effective dose equivalent factor of 0.061 mSv (Bq m{sup -3}){sup -1}. Indoor measurements were taken in more than 1000 dwellings and public and industrial buildings of 21 towns and villages. The track chambers were exposed for about 2-3 months and the charcoal ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this document is to provide the definition and means of maintaining the Safety Envelope (SE) related to the Criticality Alarm System (CAS). This document provides amplification of the Limiting Condition for Operation (LCO) described in the Plutonium Finishing Plant (PFP) Operational Safety Requirements (OSR), WHC-SD-CP-OSR-010, Rev. 0, 1994, Section 3.1.2, Criticality Detectors and Alarms. This document, with its appendices, provides the following: (1) System functional requirements for determining system operability (Section 3); (2) A list of annotated system block diagrams which indicate the safety envelope boundaries (Appendix C); (3) A list of the Safety Class 1 and 2 Safety Envelope (SC-1/2 SE) equipment for input into the Master Component Index (Appendix B); (4) Functional requirements for individual SC-1/2 SE components, including appropriate setpoints and ...

British Library Electronic Table of Contents (United Kingdom)

An energy transfer and conversion model for high-temperature solar cavity receivers has been developed using the transport behaviour of solar radiation as described by the spectral radiative exchange factors. A Monte-Carlo ray-tracing method coupled with optical properties was adopted, to predict radiation characteristics of the solar collector system by calculating radiative exchange factors. A cavity receiver with a plano-convexo quartz window was proposed, based upon the directional characteristics of the focal flux and the redistribution effect of the quartz window. Parametric studies on the windowed receiver provided a more uniform flux distribution, higher efficiency and lower loss than the windowless receivers. The predicted results serve as a design reference for the solar receiver...

Energy Technology Data Exchange (ETDEWEB)

The superconducting Tevatron accelerator at Fermi National Accelerator Laboratory (Fermilab) has surpassed twenty years of operation. The Tevatron is still the highest energy particle accelerator in the world and will remain so until the commissioning of the LHC in Europe later this decade. The Tevatron has operated in a Fixed Target mode, accelerating a proton beam into stationary targets/detectors, as well as a Colliding Beam mode, continuously colliding counter rotating beams of protons and antiprotons. Upon completion, the Tevatron cryogenic system became the world's largest helium refrigeration system. In 1993, the Tevatron cryogenic system was given the designation of International Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers. The operational history, experiences and statistics of the Tevatron, with an emphasis on the cryogenic ...

International Nuclear Information System (INIS)

A computer-based beam dosimetry measurement system for boron neutron capture therapy provides accurate, sensitive, and rapid readout and recording of all beam dose components, epithermal and thermal neutron flux, and gamma-ray dose rate. This dosimetric system includes input from the characterization of the epithermal neutron beam developed at the Massachusetts Institute of Technology, actual BPA pharmacokinetic data from a specific human subject being irradiated, output of MacNCTPLAN, a treatment planning system developed by the authors group, and input from the five on-line beam detectors. The purpose of this system and associated readout systems is to ensure that the desired dose is delivered to the subject within acceptable dose tolerances, e.g., #+-#5% of the target dose, and that any perturbations in the neutron beam that may occur during irradiation can ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

A 4{pi} detection system sensitive to light charged particles is being developed at the Laboratori Nazionali di Legnaro (LNL) for the study of reaction mechanisms at energies up to 20 AMeV. The array consists of 262 {Delta}E-E telescopes covering 90% of 4{pi}. Each telescope is made of a 300 {mu}m passivated silicon detector and a 15 mm (or 5 mm) CsI(Tl) crystal read by a photodiode. The system will be operational in the Spring of 1997 and the first experiments will run in the second half of 1997.

Energy Technology Data Exchange (ETDEWEB)

We describe a position-sensitive event-counting microchannel plate detector with a quadrant anode readout system that combines the advantages of several centroid-finding readout techniques. The relative amount of charge collected by each quadrant of the anode mounted behind the output side of the microchannel plate is used to localize each event. The position-sensitive area is about 80% of the active microchannel plate surface. By changing a single voltage a remote-controlled image magnification can be achieved. Due to a correction function that minimizes image distortions the imaging characteristics of this low-cost readout system are similar to those of expensive resistive anodes.

International Nuclear Information System (INIS)

We describe a position-sensitive event-counting microchannel plate detector with a quadrant anode readout system that combines the advantages of several centroid-finding readout techniques. The relative amount of charge collected by each quadrant of the anode mounted behind the output side of the microchannel plate is used to localize each event. The position-sensitive area is about 80% of the active microchannel plate surface. By changing a single voltage a remote-controlled image magnification can be achieved. Due to a correction function that minimizes image distortions the imaging characteristics of this low-cost readout system are similar to those of expensive resistive anodes. (orig.).

International Nuclear Information System (INIS)

Fusion device produces high-level neutrons and #gamma#-rays, which would hazard the safety of the public and workers if the doses would be higher than the regulatory limits because of leakage from the bio-shielding and skyshine. It is essential to monitor the radiation doses in the workshop and the enumerative around fusion devices. A radiation monitoring system (RMS) for full (near and far) areas around a nuclear fusion device has been designed and developed, which can achieve the monitoring and controlling of radiation doses in the workshop area by using the Controller Area Network (CAN), in the institution area by using the Bluetooth Ad hoc network based on a new tree topology formation and routing protocol and in a long range environment by using the General Packet Radio Service (GPRS) network. (authors)

Science.gov (United States)

Photodiode Scintillation Detector for Anticoincidence Shielding An important goal of space research is to understand the physics involved in the activity of ...

Energy Technology Data Exchange (ETDEWEB)

An experimental plan for improving the problems of failed fuel location system in Wolsung Unit-2 reactors was established. It is not possible to make an experiment on the failed fuel monitoring nuclides in the cold laboratories because they have very short half life. Therefore, the experiments can be only carried out at the existing monitoring system under reactor operation. For that reason, an experimental plan was drawn up for installing the radiation detection system on reactor site.

International Nuclear Information System (INIS)

Radiation exposure control is one of the most important aspects in any nuclear facility . It encompasses continuous monitoring of the various areas of the facility to detect any increase in the radiation level and/or the air activity level beyond preset limits and alarm the O and M personnel working in these areas. Detection and measurement of radiation level and the air activity level is carried out by a number of monitors installed in the areas. These monitors include Area Gamma Monitors, Continuous Air Monitors, Pu-In-Air Monitors, Criticality Monitors etc. Traditionally, these measurements are displayed and recorded on a Central Radiation Protection Console(CRPC), which is located in the central control room of the facility. This methodology suffers from the shortcoming that any worker required to enter a work area will have to inquire about the radiation status of the area ...

Energy Technology Data Exchange (ETDEWEB)

The results of radon concentration measurements inside of the Gabriel caves of Mexico, during three consecutive two-month periods covering almost three seasons, are reported in the present work. The radio-ecological importance of this site is related to the radon and its concentration-dynamic behavior in the cave. Further interest in radiation safety motivated this initiative since routine biological field work is done, with people spending long periods of time there. CR-39 passive nuclear track detector was chosen for this survey. Radon concentration levels decrease during the rainy season and show different values depending on the ventilation and geometeorological structure. Measured values range between 956 and 4931Bqm{sup -3}, an indication that radon doses may exceed the allowed values for workers. This project is part of a larger study of indoor radon alpha emitters in Mexican caves.

International Nuclear Information System (INIS)

Neutron resonance interactions with "1"0"0Mo were studied at a time-of-flight facility. The transmission of two oxide samples (97.4% "1"0"0Mo) was measured at a 78.20 m flight path and the neutron capture cross section was measured at 40.12 m. Resonance analyses yielded parameters of 124 resonances. Capture #gamma#-ray spectra from 11 resolved resonances were measured with a Ge(Li) detector at a 10.45 m flight path. In contrast to neighboring nuclei, partial radiation widths of strong p-wave resonances are not in agreement with valence model predictions.

Energy Technology Data Exchange (ETDEWEB)

A method for determining the mobility of hydrogen as a function of temperature in superconducting niobium cavities comprising: 1) heating a cavity under test to remove free hydrogen; 2) introducing hydrogen-3 gas into the cavity; 3) cooling the cavity to allow absorption of hydrogen-3; and 4) measuring the amount of hydrogen-3 by: a) cooling the cavity to about 4.degree. K while flowing a known and regulated amount of inert carrier gas such as argon or helium into the cavity; b) allowing the cavity to warm at a stable rate from 4.degree. K to room temperature as it leaves the chamber; and c) directing the exit gas to an ion chamber radiation detector.

Energy Technology Data Exchange (ETDEWEB)

Neutron capture ..gamma..-ray spectra have been measured at 11 average neutron energies from 10 to 530 keV in /sup 88/Sr using a 20 x 15 cm NaI detector with time-of-flight discrimination of background events. The partial radiation widths and the calculated partial valence widths are compared for the strong p-wave resonances at 287 and 321 keV and found to be highly correlated. At these energies, the spectra are dominated by strong transitions to low-lying single particle states, in confirmation of the role of valence capture in the 3p region. However, the data do not support this mechanism at <508> keV.

Science.gov (United States)

X-ray diffraction offers a unique combination of advantages for kinetic study which include the non-destructive nature of the measurement, the use of bulk crystals, and the convenience of the experimental arrangements. These attributes and the availability of position-sensitive detectors and high-flux synchrotron radiation sources make this technique most useful for in situ, dynamical investigations. When using diffraction techniques to determine a diffusion coefficient, the principle of analysis entails a scattering theory and a kinetic model. The former allows the kinetic parameter(s) to be extracted from measured intensity, while the latter relates the kinetic parameter(s) to the diffusion coefficient(s). Three examples are demonstrated: (1) Palladium Silicide (Pd{sub 2}Si) Layer Growth on Silicon, (2) Decomposition of an Ni-12.5at%Si Superalloy, and (3) Short-range Ordering in Cu-Au Solid Solutions.

Energy Technology Data Exchange (ETDEWEB)

Neutron radiography has been put to practical use in foreign countries as one of nondestructive inspection technologies, but in Japan, its application to other scientific fields is mainly researched. The reason is, the neutron radiography apparatuses installed in Japan are hard to be industrially utilized for a number of reasons, but also the characteristics of neutron radiography are not clearly established, and it is not standardized. The part from a collimator through an object to a detector is called ``upstream``, the part of an image detector is called ``midstream``, and the part of image processing is called ``downstream``. The nonparallel property of beam, image distortion and the lack of sharpness, beam quality and the interaction of neutron beam with an object are discussed about the upstream. The intensity of neutron beam, the energy spectra, the effective total macroscopic cross section, the effective energy, the evaluation of ...

Energy Technology Data Exchange (ETDEWEB)

This report is a survey of the English language literature of radiation biology between 1947 and 1987, for the purpose of compiling a literature base on the effects of radiation on animals, which have yielded results that can expand our knowledge about similar radiation effects on human beings. Articles were sought that reported exposure of adult mammals to external sources of ionizing radiation, having endpoints that included effects on the brain, the spinal cord, and behavior of the gastrointestinal, endocrine, and cardiovascular systems and the hematopoietic and immune systems. Effects of interest were those that occurred within the first 12 months after exposure. The survey does not include articles reporting chronic or long term delayed effects of radiation unless they provided insight into mechanisms of morphological and/or functional ...

International Nuclear Information System (INIS)

There are three main types of radiation-processed composite material derived from plastics and fibrous natural polymers. The first are the monomer-impregnated, radiation-treated wood-plastic composites (WPC). They became a commercial success in the early 1970s. More recently, work has focused on improving the WPCs by creating in them interpenetrating network (IPN) systems by the use of appropriate multifunctional oligomers and monomers. The main kinetic features of radiation-initiated chain polymerization remain applicable even in impregnated wood. The second type are the plastics filled or reinforced with dispersed wood fiber or other cellulosics (WFRP). In their case, radiation processing offers a new opportunity to apply radiation-reactive adhesion promoters between wood or cellulosic fibers and the thermoplastic matrices. The third type are the laminar ...

Science.gov (United States)

The optically stimulated luminescent (OSL) radiation dosimeter technically surveys a wide dynamic measurement range and a high sensitivity. Optical fiber dosimeters provide capability for remote monitoring of the radiation in the locations which are difficult-to-access and hazardous. In addition, optical fiber dosimeters are immune to electrical and radio-frequency interference. In this paper, a novel remote optical fiber radiation dosimeter is described. The optical fiber dosimeter takes advantage of the charge trapping materials CaS:Ce, Sm that exhibit OSL. The measuring range of the dosimeter is from 0.1 to 100 Gy. The equipment is relatively simple and small in size, and has low power consumption. This device is suitable for measuring the space radiation dose and also can be used in high radiation dose condition and other dangerous radiation occasions. ...

International Nuclear Information System (INIS)

This system provides data logging facility for axial profile and dynamic profile experiments during low power physics experiments. The data from Cobalt Self Powered Neutron Detectors (SPNDs) are logged via hardware consisting of PC plug-in cards and data of vanadium SPNDs are logged from the Flux Mapping System (FMS) network (multicast data). The data along with programmable details of the experiment is transferred to an Access Database. The system provides online displays and extensive reports from the Access Database as per the requirement from Reactor Physicists. This paper briefly describes the evolvement of requirements (from the experience of operation of TAPS 4 to TAPS 3), software architecture and design. (author)

International Nuclear Information System (INIS)

New experiment of radiography in using Fuji Intelligent Diagnostic X-ray System was first reported in XV International Congress of Radiology, 1981. By utilizing this system instead of traditional screen/film system, high density imaging plate in conjunction with computed image processor was developed, this is FCR. However, as the numerous problems in regard to the basic side of FCR system are found, it is expected that these are solved by investigators at their earliest opportunities. The purpose of this study is to reduce the radiation doses of the patients at radiography of the chest by using FCR system installed in our Department of Radiology in July, 1984. Experimentally we measured the radiation doses of the patient having the each breast of 18, 20, 22 and 24cm in thickness at radiography of the chest by using VICTOREEN MODEL 666 survey ...

International Nuclear Information System (INIS)

As there are many efforts devoted in order to manage the cancer, here the researcher handle one of these efforts that play a major part in treating the cancer internationally, it is a brachytherapy system. Brachytherapy was carried out mostly with radium sources, but recently some artificial sources are incorporated in this mode of treatment such as Cs-137, Ir-192, Au-198, P-32, Sr-90 and I-125. The research cover history of brachytherapy and radioactive sources used in, techniques of implementation, radiation protection and methods of brachytherapy dose calculation, as well as brachytherapy in radiation and isotopes centre in Khartoum.

British Library Electronic Table of Contents (United Kingdom)

Resonant scattering of atoms with formation of the Feshbach resonance in the presence of a laser radiation coupling the levels of two bound atoms (a molecule) is considered. The laser field leads to a second resonance in scattering and broadening of resonances, which facilitates the possibility of experimental observation of asymmetry of the total scattering cross-section arising because of interference between resonant and potential scatterings. The effects associated with interference of the two channels of decay of a bound system of two atoms (a molecule) in the laser field are studied. An expression is obtained for the scattering length in collision of two cold atoms in the field of laser radiation.

Energy Technology Data Exchange (ETDEWEB)

Wood-plastic composites (WPC) have been prepared with five low-grade woods, native to Syria, using three monomer systems; acrylamide, butylmethacrylate, and styrene, with methanol as the swelling solvent. Polymerization was induced at various radiation doses (10, 20, and 30 kGy) at a dose rate of 3.5 kGy/h using a {sup 60}Co gamma radiation source. Some physical properties of WPC, namely polymer loading and compression strength have been measured. The polymer loading decreases approximately with increasing density of the wood species used.

International Nuclear Information System (INIS)

Wood-plastic composites (WPC) have been prepared with five low-grade woods, native to Syria, using three monomer systems; acrylamide, butylmethacrylate, and styrene, with methanol as the swelling solvent. Polymerization was induced at various radiation doses (10, 20, and 30 kGy) at a dose rate of 3.5 kGy/h using a "6"0Co gamma radiation source. Some physical properties of WPC, namely polymer loading and compression strength have been measured. The polymer loading decreases approximately with increasing density of the wood species used. (author)

Energy Technology Data Exchange (ETDEWEB)

Pilot-plant irradiation began in Hungary in 1969 with the construction of a high-activity multi-purpose /sup 60/Co facility. Technologies for radiation sterilization, food handling, plastics irradiation as well as chemical dosimetry, semiconductor instrumental dosimetry, computer-based construction and control methods have been developed. Our chlorobenzene dose-meter system is used in Hungary and abroad; as a result of an IAEA-organized dosimetric intercomparison the system was adopted as a reference system. The institute has developed into a basic institute for the reconstruction and re-load of old ..gamma..-facilities as well as it serves for the planning, construction and launching of new ones in Hungary.

Energy Technology Data Exchange (ETDEWEB)

A new generation of quasimonochromatic high-flux X-ray sources, based on the X-ray radiation produced through Compton scattering between an electron beam and a laser beam, is under development. One of the possible applications of this source is inline phase contrast mammography, based on the observation of the edge-enhancement effect that can be observed at the border of structures inside the breast in images produced using a partially or totally coherent X-ray beam. In this work we present the results of a set of simulations of inline phase contrast mammography using typical inverse Compton scattering sources parameters. The simulated sample was a tumour-like mass having spherical shape, diameter between 200 {mu}m and 5 mm, placed inside a breast-like matrix, 4 cm thick, and a standard composition of 50% glandular tissue and 50% adipose tissue. We discuss the minimum requirements for mammography using inverse Compton scattering sources and we discuss how the ...

International Nuclear Information System (INIS)

A patent is claimed for the invention of a hardening (ionizing radiation resistance) process for MOS type components and CMOS or bipolar type components. The ionizing radiation effect on those systems is the electron-hole pair production, which induces interference phenomena. The MOS main structure is successively composed of a silicon substrate layer, a layer of an irradiation resistant material and a layer of partially monocrystalline silicon.

International Nuclear Information System (INIS)

The Albedo Theory was applied in order to develop an one-group algorithm for coupled neutron-gamma shielding calculations. The configuration analyzed consists of multilayered plane systems, where a incident neutron current generates gamma radiation through neutron-gamma reactions. The results obtained by Albedo Method and ANISN code have shown excellent agreement. (author)

International Nuclear Information System (INIS)

Large sized reactor such as 540 MWe Pressurised Heavy Water Reactor (PHWR) requires continuous in core monitoring of local flux in order to provide effective control and protection. About 198 self powered neutron detectors (SPNDs) of the straight individually replaceable type are distributed in the reactor core. For purposes of reactor regulation, 42 prompt responding cobalt SPNDs called zone control detectors (ZCDs) are housed in vertical flux units (VFUs) and these are uniformly distributed in 14 power zones. The in core detectors used for spatial control by ZCCs do not accurately represent average zone power as they sense the flux over a small volume. Flux mapping system (FMS) comprising of 102 vanadium SPNDs in 26 VFUs, provide accurate measure of neutron flux, even though they have slow response to change in neutron flux levels. For reactor protection system-1 (RPS-1), 36 ...

International Nuclear Information System (INIS)

Full text: The principal nuclear design tools available to the shielding designer include diffusion approximation, transport theory, and Monte Carlo techniques. Full transport theory or Monte Carlo methods are routinely used for shielding analyses, where penetration investigations are more sensitive to directional aspects. However, the aim of this paper is to illustrate the coupled neutron-gamma Albedo method particularly as applied to problems of shielding analysis. The multigroup Albedo method is applied to coupled neutron-gamma radiations considering 'n' neutron energy groups and 'g' gamma energy groups to estimate the probabilities of transmission through, absorption in, and reflection from shieldings composed by multiple material layers, 'm' slabs, in which no fission occurs. In this study, these energy groups were selected in order to minimize upscattering effects of the radiation from lower energy groups to higher energy groups. However, ...

Energy Technology Data Exchange (ETDEWEB)

A 2.45 MeV neutron time-of-flight spectrometer was designed and built for measurements of neutron energy spectra from the JT-60U Tokamak. The spectrometer consists of two fast plastic scintillators (50 cm{sup 2} and 1800 cm{sup 2}, thickness: 2 cm) where each detector is located on two constant time-of-flight spheres. The time-of-flight spheres have radius of 1 m which gives a neutron flight length of {approx}164 cm and a time-of-flight of {approx}92 ns for 2.45 MeV source neutrons. The calculated spectrometer efficiency and resolution are 2.8 x 10{sup -2} cm{sup 2} and 105 keV (4.3%), respectively. The energy resolution corresponds to a time resolution of 2.0 ns. The spectrometer will measure neutrons in a vertical line-of-sight, {approx}9 m from the plasma center. For a total neutron emission of 10{sup 16} n/s, the countrate in the first scattering detector, located in the neutron beam, is estimated to {approx}2.5 MHz. The useful countrate ...

Energy Technology Data Exchange (ETDEWEB)

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.

International Nuclear Information System (INIS)

The half-life of "1"0"9Cd was measured by following the decay of sources from a radiochemically pure solution with two different measuring systems: an ionisation chamber and a high-purity germanium (HPGe) detector. The measurements were performed over a period of 3.6 years, i.e. about 2.8 half-lives of "1"0"9Cd. The resulting half-life values and detailed uncertainty budgets (k=1) are presented for both systems. The result obtained with the ionisation chamber, 462.36 (33) days, and the one obtained with the HPGe detector, 461.92 (76) days, are mutually consistent. The weighted mean of our measured values, T_1_/_2("1"0"9Cd)=462.29 (30) days, is consistent with the currently recommended values of 461.4 (12) days and 462.0 (3) days. From a set of selected experimental values published after 1970, a 'partially weighted mean' of T_1_/_2("1"0"9Cd)=462.36 (39) days was calculated. More measurements are needed ...

British Library Electronic Table of Contents (United Kingdom)

For the safety of astronauts and to ensure the stability and integrity of the genome of microorganisms and plants used in bioregenerative life support systems, it is important to improve our knowledge of the combined action of (space) radiation and microgravity. The SOS-LUX-TOXICITY test, as part of the TRIPLE-LUX project (accepted for flight at Biolab in Columbus on the International Space Station, (ISS)), will provide an estimation of the health risk resulting from exposure of astronauts to the radiation environment of space in microgravity. The project will: (i) increase our knowledge of biological/health threatening action of space radiation and enzymatic DNA repair; (ii) uncover cellular mechanisms of synergistic interaction of microgravity and space radiation; (iii) provide specified...

Energy Technology Data Exchange (ETDEWEB)

A 38 year old male dentist developed an oligodendroglioma of the left medial temporal lobe and parasellar region 12 years after radiotherapy with 6600 rads for acromegaly. The 30 cases of radiation-induced gliomas reported in the English literature are reviewed and analysed. The criteria for defining radiation-induced tumours of the central nervous system are proposed as follows: the tumour has a long quiescent ''latency period'', a location in the previously irradiated field, a verified histological difference from a primary condition, and does not arise from a primary condition associated with a genetic syndrome such as neurofibromatosis or tuberous sclerosis. The reported case fulfilled these criteria but appears to be the only reported radiation-induced oligodendroglioma.