WorldWideScience
1

Absolute radioactivity measurements  

International Nuclear Information System (INIS)

The radioactivity of a thin specimen can be determined directly, i.e. without reference to a standard and without knowing decay data, except for half-life, by means of counting at a given solid angle and by 4 ??-? coincidence measurement. In accordance with section 7 of the law on units, it is the task of PTB not only to represent the units and its derivation, but also to work out methods of adjusting national prototypes and normals to international prototypes and etalons in accordance with the international metre convention. (DG)

2

4??-? anti-coincidence absolute radioactivity measurement system  

International Nuclear Information System (INIS)

A 4??-? anti-coincidence system has been developed for absolute radioactivity measurement. In this system, a dual ADC live-time HPGe ?-spectroscopy is used as the ?-ray detector, and a 4?? proportional counter is employed for the ? detector. The activity of 60Co, 134Cs and 166mHo have been measured. The combined standard uncertainty of 60Co, 134Cs and 166mHo, is 0.24%, 0.33%, 0.40%, respectively. The data of two former nuclei are compared with the results of 4??-? coincidence counting system of NIM and CIAE and the agreement of these results is satisfactory. The decay-scheme of 166mHo is so complex that an adequate accuracy by using other methods is not acquired. It is also obtained that the result of anti-coincidence measurement is independent on ? efficiency. At last, the relative questions in this study are also discussed

3

Absolute measurement of strontium-90 and yttrium-90 radioactivity  

International Nuclear Information System (INIS)

Strontium-90 and yttrium-90 is one of the important fission products. At present it is applied widely in industry because its half life is longer and its fission yield is higher. The radioactivity of the nuclide is concerned by human, because strontium-90 and Yttrium-90 is extremely poisonous for living things. The purpose of present work is to provide the standardization of strontium-90 and yttrium-90 radioactivity for the isotopic application and for the reprocessing plant. Method of determing strontium-90 and yttrium-90 radioactivity is efficiency trace technique while cobalt-60 nuclide is used as tracer. The total uncertainty of measurement is about ±1.4 percent

4

Calibrated radioactive sources - absolute measurements using a 4? ?-? apparatus  

International Nuclear Information System (INIS)

In this paper, the principle of the standardization of the radioisotopes by the 4? ? - ? coincidence method is reminded. Some theoretical examples are given emphasizing on instrumental coincidences and their corrections. The experimental apparatus is described: one discusses the choice of the experimental conditions for the many isotopes measured. Results are given and discussed. In appendix we describe the preparation of the sources. (authors)

5

Absolute radioactivity measurement of 60Co and 134Cs by 4??-? anti-coincidence method  

International Nuclear Information System (INIS)

A 4??-? anti-coincidence system is developed for absolute radioactivity measurement. In this system, a dual ADC live-time HPGe ?-spectroscopy is used as the ?-ray detector, and a 4?? proportional counter is employed for the ? detector. The activities of 60Co and 134Cs are measured by this system. The combined standard uncertainty of 60Co and 134Cs is 0.24% and 0.33%, respectively. The results are compared with that from 4??-? coincidence counting system of NIM and CIAE and the agreement of these results is satisfactory

6

Radioactivity measurements of 177Lu, 111In and 123I by different absolute methods  

International Nuclear Information System (INIS)

The activities of 177Lu, 111In and 123I solutions have been absolutely determined using three different measurement methods. 177Lu solution was standardized using the 4??(PC)–?(NaI) coincidence and 4??(LS)–?(NaI) live-timed anticoincidence methods. For the 111In and 123I solutions, besides these two mentioned methods, the coincidence sum-peak method was also applied. The measured activities results using these different methods are consistent within the evaluated experimental uncertainties demonstrating the equivalence of these methods. As an additional contribution to nuclear data, the half-lives have been determined using a well type IG12 ionization chamber. - Highlights: ? Lu-177, I-123 and In-111 have been absolutely standardized by different methods. ? Results between methods agreed within evaluated uncertainties. ? 3-Half-lives were also measured and compared with recent published results.

7

Absolute measurement of the radioactivity of 139Ce with 4? solid scintillation method  

International Nuclear Information System (INIS)

Based on its single ?-ray and low-energy, the radioactivity of 139Ce was measured with both 4? CsI(Tl) and NaI(Tl) method. The advantages of the methods are higher detection efficiency and simplicity in use. The results obtained from the two methods are in good agreement. (authors)

8

Measuring the absolute disintegration rate of a radioactive gas with a moveable endplate discharge counter (MEP) and theoretical calculation of wall effect  

International Nuclear Information System (INIS)

A precision built moveable endplate Geiger-Mueller counter was used to measure the absolute disintegration rate of a beta-emitting radioactive gas. A Geiger-Mueller counter used for measuring gaseous radioactivity has 85Kr (beta energy, 0.67 MeV). The wall effect calculation is readily extendable to other beta energies

9

Absolute radioactivity measurement of 60Co, 134Cs and 166mHo by 4??-? anti-coincidence method  

International Nuclear Information System (INIS)

A 4??-? anti-coincidence system has been developed for absolute radioactivity measurements with a HPGe ?-spectrometer used as the ?-ray detector and a 4?? proportional counter as the ? detector. The activity of 60Co, 134Cs and 166mHo have been measured with the combined standard uncertainties of 0.24%, 0.33% and 0.44%, respectively. Compared with the results of the National Institute of Metrology and 4??-? coincidence counting system of the China Institute of Atomic Energy, the agreement of the results of 60Co and 134Cs is satisfactory. For 166mHo, the results obtained using other methods by most national and international labs lack sufficient accuracy due to the complex decay scheme of this radio-nuclide. It is also concluded that the result of anti-coincidence measurement is independent of ? efficiency

10

Absolute measurements of radio-active bodies which disintegrate after neutron capture (1962)  

International Nuclear Information System (INIS)

The calibration of radioactive bodies which disintegrate by neutron capture is rather delicate: we describe two calibration methods which we have used. - The 4 ? X (or e) - ? coincidence method when K capture is followed by a ? disintegration; - Integral counting of all the X rays stopped in the detecting volume, for X-ray emitters of low energy disintegrating after neutron capture giving directly the fundamental level. (authors)

11

Measurement of the absolute activity of alpha or beta emitters by measuring product nuclei (daughter) activity increase or by studing its radioactive decay  

International Nuclear Information System (INIS)

A new method for determining absolute activity of alpha or beta emitters by measuring daughter product radioactive decay is presented. The separation method of UX from hexahydrated uranyl nitrate UO2(NO3)2 6H2O based on its dissolution in ethyl ether is described and the accuracy of this method is shown. The factors which accuate on total efficiency of a Geiger Mueller detector for beta particles are determined. The possibility to determine the mass of precursor element by daughter nuclei activity is shown. The results are compared with the one obtained by direct measurement of the mass (or number of atoms) of precursor radioactive substance and with theoretical values calculated for isotopes in secular equilibrium. (Author)

12

Measurement of the absolute \  

Energy Technology Data Exchange (ETDEWEB)

This thesis presents the measurement of the charged current quasi-elastic (CCQE) neutrino-nucleon cross section at neutrino energies around 1 GeV. This measurement has two main physical motivations. On one hand, the neutrino-nucleon interactions at few GeV is a region where existing old data are sparse and with low statistics. The current measurement populates low energy regions with higher statistics and precision than previous experiments. On the other hand, the CCQE interaction is the most useful interaction in neutrino oscillation experiments. The CCQE channel is used to measure the initial and final neutrino fluxes in order to determine the neutrino fraction that disappeared. The neutrino oscillation experiments work at low neutrino energies, so precise measurement of CCQE interactions are essential for flux measurements. The main goal of this thesis is to measure the CCQE absolute neutrino cross section from the SciBooNE data. The SciBar Booster Neutrino Experiment (SciBooNE) is a neutrino and anti-neutrino scattering off experiment. The neutrino energy spectrum works at energies around 1 GeV. SciBooNE was running from June 8th 2007 to August 18th 2008. In that period, the experiment collected a total of 2.65 x 10{sup 20} protons on target (POT). This thesis has used full data collection in neutrino mode 0.99 x 10{sup 20} POT. A CCQE selection cut has been performed, achieving around 70% pure CCQE sample. A fit method has been exclusively developed to determine the absolute CCQE cross section, presenting results in a neutrino energy range from 0.2 to 2 GeV. The results are compatible with the NEUT predictions. The SciBooNE measurement has been compared with both Carbon (MiniBoonE) and deuterium (ANL and BNL) target experiments, showing a good agreement in both cases.

Aunion, Jose Luis Alcaraz; /Barcelona, IFAE

2010-07-01

13

Measuring the absolute disintegration rate of a radioactive gas with a moveable endplate discharge counter (MEP) and theoretical calculation of wall effect  

Energy Technology Data Exchange (ETDEWEB)

A precision built moveable endplate Geiger-Mueller counter was used to measure the absolute disintegration rate of a beta-emitting radioactive gas. A Geiger-Mueller counter used for measuring gaseous radioactivity has <100% counting efficiency owing to two factors: (1) ''end effect,'' due to decreased and distorted fields at the ends where wire-insulator joints are placed, and (2) ''wall effect,'' due to non-ionization by beta particles emitted near to and heading into the wall. The end effect was evaluated by making one end of the counter movable and measuring counting rates at a number of endplate positions. Much of the wall effect was calculated theoretically, based on known data for primary ionization of electrons as a function of energy and gas composition. Corrections were then made for the ''shakeoff'' effect in beta decay and for backscattering of electrons from the counter wall. Measurements and calculations were made for a sample of /sup 85/Kr (beta energy, 0.67 MeV). The wall effect calculation is readily extendable to other beta energies.

Jaffey, A.H.; Gray, J.; Bentley, W.C.; Lerner, J.L.

1987-09-01

14

Absolute measurement of optical attenuation  

International Nuclear Information System (INIS)

We have discovered that laser beam deflection spectroscopy can be used for the absolute measurement of wave or particle beam attenuation in condensed matter. The concept has been experimentally evaluated by successfully measuring the absolute optical attenuation in a crystal of U3+:CaF2 at 514 nm. A theoretical model that explains the experiment and characterizes the range of applicability of the method has been developed

15

Measurement of Disintegration Rates and Absolute ?-ray Intensities  

International Nuclear Information System (INIS)

The majority of practical radioactive materials decay by modes that include ?-ray emission. For questions of 'how much' or 'how pure', one must know the absolute intensities of the major radiations. We are using liquid scintillation counting (LSC) to measurements of disintegration rates, coupled with ?-ray spectroscopy to measure absolute ?-ray emission probabilities. Described is a study of the 227Th chain yielding absolute ?-ray intensities with ?0.5% accuracy and information on LSC efficiencies

16

Active radiometric calorimeter for absolute calibration of radioactive sources  

International Nuclear Information System (INIS)

This report describes the design and initial noise floor measurements of a radiometric calorimeter designed to measure therapeutic medical radioactive sources. The instrument demonstrates a noise floor of approximately 2 nW. This low noise floor is achieved by using high temperature superconducting (HTS) transition edge sensor (TES) thermometers in a temperature-control feedback loop. This feedback loop will be used to provide absolute source calibrations based upon the electrical substitution method. Other unique features of the calorimeter are (a) its ability to change sources for calibration without disrupting the vacuum of the instrument, and (b) the ability to measure the emitted power of a source in addition to the total contained source power

17

Absolute measurement of 152Eu  

International Nuclear Information System (INIS)

A new method of the absolute measurement for 152Eu was established based on the 4??-? spectroscopic anti-coincidence method. It is a coincidence counting method consisting of a 4??-counter and a Ge(Li) ?-ray detector, in which the effective counting efficiencies of the 4??-counter for ?-rays, conversion electrons, and Auger electrons were obtained by taking the intensity ratios for certain ?-rays between the single spectrum and the spectrum coincident with the pulses from the 4??-counter. First, in order to verify the method, three different methods of the absolute measurement were performed with a prepared 60Co source to find excellent agreement among the results deduced by them. Next, the 4??-? spectroscopic coincidence measurement was applied to 152Eu sources prepared by irradiating an enriched 151Eu target in a reactor. The result was compared with that obtained by the ?-ray spectrometry using a 152Eu standard source supplied by LMRI. They agreed with each other within the error of 2%. (author)

18

Environmental radioactivity measurements  

International Nuclear Information System (INIS)

In our surroundings there exist both natural and artificial radioactive materials. The analysis or measurements of such environmental radioactivities are important not only in geochemistry but also in grasping radioactive contamination of the environment and the influences of radiation on the human body. Before the measurements, chemical forms and dissolved states of the radioactive materials in the environment need to be known. A review is made of the papers etc. published mostly since 1977, concerning environmental radioactivity measurements: pretreatment and collection of radioactive nuclides; measurements of artificial radioactive nuclides (radiocobalt, radiostrontium and radiocesium, radioiodine, transuranium elements, etc.); measurements of natural radioactive nuclides (uranium and thorium isotopes, radium isotopes, etc.); environmental radioactivity measurements manual. (Mori, K.)

19

Radioactivity and its measurement  

CERN Document Server

Begins with a description of the discovery of radioactivity and the historic research of such pioneers as the Curies and Rutherford. After a discussion of the interactions of &agr;, &bgr; and &ggr; rays with matter, the energetics of the different modes of nuclear disintegration are considered in relation to the Einstein mass-energy relationship as applied to radioactive transformations. Radiation detectors and radioactivity measurements are also discussed

Mann, W B; Garfinkel, S B

2013-01-01

20

Measurement of radioactive aerosols  

International Nuclear Information System (INIS)

Radioactive nuclei or atoms released in the atmospheric environment may lead to the formation of radioactive aerosols which are widely used as a tracer for investigating atmospheric transport and diffusion. Aerosols collection methods are presented followed by radioactivity measurement including alpha-rays (proportional counters), beta-rays (gas-flow counters), and gamma radiations NaI scintillation and germanium semiconductor counters). For discriminating the nuclei, silicon semi-conductor or liquid scintillation counter are used. For particulate radius measurement, several methods such as impact, diffusion battery, and track detector counting are used. (S. Ohno)

21

Absolute radioactivity measurements of sup 1 sup 5 sup 3 Sm, sup 1 sup 8 sup 8 Re, sup 8 sup 9 Sr and national comparisons  

CERN Document Server

sup 1 sup 5 sup 3 Sm and sup 1 sup 8 sup 8 Re are short half-life nuclides and sup 8 sup 9 Sr is one of pure beta-decay nuclide, these nuclides have being applied to nuclear medicine. It's very important to carry out comparisons for radioactivity standardization of these nuclides. Several laboratories in China including our laboratory took part in the comparisons. The results from our laboratory are in good agreement with the mean values

Wang Jian Qing; Yao Yan Ling; Jia Xue Wen

2003-01-01

22

Precision absolute positional measurement of laser beams  

OpenAIRE

We describe an instrument which, coupled with a suitable coordinate measuring machine, facilitates the absolute measurement within the machine frame of the propagation direction of a millimeter-scale laser beam to an accuracy of around ±4???m in position and ±20???rad in angle.

Fitzsimons, E. D.; Bogenstahl, J.; Hough, J.; Killow, C. J.; Perreur-lloyd, M.; Robertson, D. I.; Ward, H.

2013-01-01

23

Precision absolute positional measurement of laser beams.  

Science.gov (United States)

We describe an instrument which, coupled with a suitable coordinate measuring machine, facilitates the absolute measurement within the machine frame of the propagation direction of a millimeter-scale laser beam to an accuracy of around ±4 ?m in position and ±20 ?rad in angle. PMID:23669658

Fitzsimons, Ewan D; Bogenstahl, Johanna; Hough, James; Killow, Christian J; Perreur-Lloyd, Michael; Robertson, David I; Ward, Henry

2013-04-20

24

Absolute measurement of 133Xe activity concentration  

International Nuclear Information System (INIS)

Noble gas xenon is one of important components for Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System (IMS). Monitoring sample was generally measured by HPGe ? spectrometer and ?-? coincidence system. How to accurately determine the detect efficiency of the system was a key point of radioactive Xe measurement. The theory and method of activity concentration measurement of radioactive Xe by internal gas proportional counting were studied. 133Xe activity concentration measured by internal gas proportional counting is 21.36 x (1±1.5%) Bq/mL. (authors)

25

Absolute Continuity in Noncommutative Measure Theory  

Science.gov (United States)

Recent results on absolute continuity of Banach space valued operators and convergence theorems on operator algebras are deepened and summarized. It is shown that absolute continuity of an operator T on a von Neumann algebra M with respect to a positive normal functional ? on M is not implied by the fact that the null projections of ? are the null projections of T. However, it is proved that the implication above is true whenever M is finite or T is weak*-continuous. Further it is shown that the absolute value preserves the Vitali-Hahn-Saks property if, and only if, the underlying algebra is finite. This result improves classical results on weak compactness of sets of noncommutative measures.

Hamhalter, Jan

2010-12-01

26

Radioactivity measurements in solid radioactive waste disposal  

International Nuclear Information System (INIS)

Radioactivity measurements on solid waste are made to determine whether the waste is radioactive, to classify the waste, and to test the waste packages prior to shipping and storage. In case of the waste - either solid, liquid or solidified - being canned in transport flasks or other container types, measurements are difficult to be carried out. Gamma-ray emitting nuclides can be measured only approximatively, alpha- and beta-ray emitting nuclides even not at all. Hence measurements are to be carried out on unpacked original waste. For calibrating the gamma measuring equipment, PTB offers suitable standards. (orig./DG)

27

Detectors for absolute luminosity measurement at DAFNE  

International Nuclear Information System (INIS)

Since the second half of year 2007, the Frascati ?- factory DAFNE has been running with an upgraded interaction region in order to test the crabbed waist collision scheme. The aim is to reach a large improvement of the specific luminosity of the accelerator. We describe the various detectors realized to have a reliable and fast absolute luminosity measurement, the on-line analysis in order to get rid of the machine background contribution, and the performances of the system.

28

Detectors for absolute luminosity measurement at DAFNE  

Energy Technology Data Exchange (ETDEWEB)

Since the second half of year 2007, the Frascati {Phi}- factory DAFNE has been running with an upgraded interaction region in order to test the crabbed waist collision scheme. The aim is to reach a large improvement of the specific luminosity of the accelerator. We describe the various detectors realized to have a reliable and fast absolute luminosity measurement, the on-line analysis in order to get rid of the machine background contribution, and the performances of the system.

Valente, P., E-mail: paolo.valente@roma1.infn.i [INFN Roma, Rome (Italy); Boscolo, M.; Bossi, F.; Buonomo, B.; Mazzitelli, G.; Murtas, F.; Sensolini, G.; Raimondi, P. [INFN LNF, Frascati (Italy); Arnaud, N.; Breton, D.; Burmistrov, L.; Stocchi, A.; Variola, A.; Viaud, B. [LAL, Orsay (France); Branchini, P. [INFN Roma Tre, Rome (Italy); Schioppa, M. [INFN Cosenza, Rende (Italy)

2010-05-21

29

Measurement of absolute gravity acceleration in Firenze  

Science.gov (United States)

This paper reports the results from the accurate measurement of the acceleration of gravity g taken at two separate premises in the Polo Scientifico of the University of Firenze (Italy). In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the Newtonian law at short distances are in progress. Both experiments require an independent knowledge on the local value of g. The only available datum, pertaining to the italian zero-order gravity network, was taken more than 20 years ago at a distance of more than 60 km from the study site. Gravity measurements were conducted using an FG5 absolute gravimeter, and accompanied by seismic recordings for evaluating the noise condition at the site. The absolute accelerations of gravity at the two laboratories are (980 492 160.6 ± 4.0) ?Gal and (980 492 048.3 ± 3.0) ?Gal for the European Laboratory for Non-Linear Spectroscopy (LENS) and Dipartimento di Fisica e Astronomia, respectively. Other than for the two referenced experiments, the data here presented will serve as a benchmark for any future study requiring an accurate knowledge of the absolute value of the acceleration of gravity in the study region.

de Angelis, M.; Greco, F.; Pistorio, A.; Poli, N.; Prevedelli, M.; Saccorotti, G.; Sorrentino, F.; Tino, G. M.

2011-01-01

30

System for absolute measurements by interferometric sensors  

Science.gov (United States)

The most common problem of interferometric sensors is their inability to measure absolute path imbalance. Presented in this paper is a signal processing system that gives absolute, unambiguous reading of optical path difference for almost any style of interferometric sensor. Key components are a wide band (incoherent) optical source, a polychromator, and FFT electronics. Advantages include no moving parts in the signal processor, no active components at the sensor location, and the use of standard single mode fiber for sensor illumination and signal transmission. Actual absolute path imbalance of the interferometer is determined without using fringe counting or other inferential techniques. The polychromator extracts the interference information that occurs at each discrete wavelength within the spectral band of the optical source. The signal processing consists of analog and digital filtering, Fast Fourier analysis, and a peak detection and interpolation algorithm. This system was originally designed for use in a remote pressure sensing application that employed a totally passive fiber optic interferometer. A performance qualification was made using a Fabry-Perot interferometer and a commercially available laser interferometer to measure the reference displacement.

Norton, Douglas A.

1993-03-01

31

Absolute Measurement of Electron Cloud Density  

Energy Technology Data Exchange (ETDEWEB)

Beam interaction with background gas and walls produces ubiquitous clouds of stray electrons that frequently limit the performance of particle accelerator and storage rings. Counterintuitively we obtained the electron cloud accumulation by measuring the expelled ions that are originated from the beam-background gas interaction, rather than by measuring electrons that reach the walls. The kinetic ion energy measured with a retarding field analyzer (RFA) maps the depressed beam space-charge potential and provides the dynamic electron cloud density. Clearing electrode current measurements give the static electron cloud background that complements and corroborates with the RFA measurements, providing an absolute measurement of electron cloud density during a 5 {micro}s duration beam pulse in a drift region of the magnetic transport section of the High-Current Experiment (HCX) at LBNL.

Covo, M K; Molvik, A W; Cohen, R H; Friedman, A; Seidl, P A; Logan, G; Bieniosek, F; Baca, D; Vay, J; Orlando, E; Vujic, J L

2007-06-21

32

Absolute measurements of neutron induced reaction rates  

International Nuclear Information System (INIS)

This paper describes techniques for the measurement of neutron-induced reaction rates on an absolute basis. Two main areas of application are discussed: determinations of threshold reactions used to monitor fast fluxes relevant to materials damage and neutron penetration. The accuracy required in these measurements is modest in view of other uncertainties, a standard error of +-10% normally being adequate; determinations of fission and capture rates in zero-power reactors which provide a basis for validation of data and calculation methods applied to the prediction of power reactor performance. Accuracies here are much more stringent, with +-1% on fission rates in the major heavy nuclides and +-0.7% in the capture rate in U-238 being target values based on neutron balance consid

33

Low-level Radioactivity Measurements  

International Nuclear Information System (INIS)

The low-level radioactivity measurements service performs measurements of alpha or beta emitters on various types of low-radioactivity samples (biological and environmental) from internal and external clients. to maintain and develop techniques concerning the measurement of low-level radioactivity of alpha and beta emitting radionuclides in environmental or biological samples; to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters and alpha-spectrometers); to support and advise the nuclear and non-nuclear industry on problems of radioactive contamination or low level radioactivity measurements; to maintain the quality assurance system according to the ISO17025 standard for which we obtained the Beltest accreditation in 1998; to assess the internal dose from occupational intakes of radionuclides for workers of the nuclear industry;

34

Elevation correction factor for absolute pressure measurements  

Science.gov (United States)

With the arrival of highly accurate multi-port pressure measurement systems, conditions that previously did not affect overall system accuracy must now be scrutinized closely. Errors caused by elevation differences between pressure sensing elements and model pressure taps can be quantified and corrected. With multi-port pressure measurement systems, the sensing elements are connected to pressure taps that may be many feet away. The measurement system may be at a different elevation than the pressure taps due to laboratory space or test article constraints. This difference produces a pressure gradient that is inversely proportional to height within the interface tube. The pressure at the bottom of the tube will be higher than the pressure at the top due to the weight of the tube's column of air. Tubes with higher pressures will exhibit larger absolute errors due to the higher air density. The above effect is well documented but has generally been taken into account with large elevations only. With error analysis techniques, the loss in accuracy from elevation can be easily quantified. Correction factors can be applied to maintain the high accuracies of new pressure measurement systems.

Panek, Joseph W.; Sorrells, Mark R.

1996-01-01

35

Radioactivity measurements principles and practice  

CERN Document Server

The authors have addressed the basic need for internationally consistent standards and methods demanded by the new and increasing use of radioactive materials, radiopharmaceuticals and labelled compounds. Particular emphasis is given to the basic and practical problems that may be encountered in measuring radioactivity. The text provides information and recommendations in the areas of radiation protection, focusing on quality control and the precautions necessary for the preparation and handling of radioactive substances. New information is also presented on the applications of both traditiona

Mann, W B; Spernol, A

2012-01-01

36

Neutronic measurements of radioactive waste  

International Nuclear Information System (INIS)

This document presents the general matters involved in the radioactive waste management and the different non destructive assays of radioactivity. The neutronic measurements used in the characterization of waste drums containing emitters are described with more details, especially the active neutronic interrogation assays with prompt or delayed neutron detection: physical principle, signal processing and evaluation of the detection limit. (author)

37

Absolute optical surface measurement with deflectometry  

Science.gov (United States)

Deflectometry utilises the deformation and displacement of a sample pattern after reflection from a test surface to infer the surface slopes. Differentiation of the measurement data leads to a curvature map, which is very useful for surface quality checks with sensitivity down to the nanometre range. Integration of the data allows reconstruction of the absolute surface shape, but the procedure is very error-prone because systematic errors may add up to large shape deviations. In addition, there are infinitely many combinations for slope and object distance that satisfy a given observation. One solution for this ambiguity is to include information on the object's distance. It must be known very accurately. Two laser pointers can be used for positioning the object, and we also show how a confocal chromatic distance sensor can be used to define a reference point on a smooth surface from which the integration can be started. The used integration algorithm works without symmetry constraints and is therefore suitable for free-form surfaces as well. Unlike null testing, deflectometry also determines radius of curvature (ROC) or focal lengths as a direct result of the 3D surface reconstruction. This is shown by the example of a 200 mm diameter telescope mirror, whose ROC measurements by coordinate measurement machine and deflectometry coincide to within 0.27 mm (or a sag error of 1.3?m). By the example of a diamond-turned off-axis parabolic mirror, we demonstrate that the figure measurement uncertainty comes close to a well-calibrated Fizeau interferometer.

Li, Wansong; Sandner, Marc; Gesierich, Achim; Burke, Jan

38

On the absolute measure of Beta activities  

International Nuclear Information System (INIS)

A new method for absolute beta counting of solid samples is given. The mea surements is made with an inside Geiger-Muller tube of new construction. The backscattering correction when using an infinite thick mounting is discussed and results for different materials given. (Author)

39

Environmental radioactivity measurement. Ispra 1990  

International Nuclear Information System (INIS)

In this report there are briefly described the measurements of environmental radioactivity performed during 1990 by the site survey group of the Radioprotection Division at the Joint Research Centre Ispra Establishment. Data are give on the concentrations of Sr-90, Cs-137, HTO and other radionuclides in precipitation, air, waters, herbage, milk and radioactive effluents. The environmental contamination is mainly a consequence of the nuclear accident of Chernobyl

40

Low-level Radioactivity Measurements  

Energy Technology Data Exchange (ETDEWEB)

The objectives of the research performed in the area of low-level radioactivity measurements are (1) to maintain and develop techniques for the measurement of low-level environmental and biological samples, (2) to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters, alpha spectrometry), (3) to support and advise the nuclear and non-nuclear industry on problems of radioactive contamination and low-level radioactivity measurements; (4) to maintain and improve the quality assurance system according to the ISO17025 standard; and (5) to assess the internal dose from occupational intakes of radionuclides of workers of the nuclear industry. Progress and achievements in these areas in 2001 are reported.

Hurtgen, C

2002-04-01

41

Low-level Radioactivity Measurements  

Energy Technology Data Exchange (ETDEWEB)

The objectives of the research performed in the area of low-level radioactivity measurements are (1) to maintain and develop techniques for the measurement of low-level environmental and biological samples, (2) to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters, alpha spectrometry), (3) to support and advice the nuclear and non-nuclear industry in matters concerning radioactive contamination and/or low-level radioactivity measurements; (4) to maintain the quality assurance system according to the EN45001/ISO17025 standard; and (5) to assess the internal dose from occupational intakes of radionuclides of workers of the nuclear industry. Progress and achievements in these areas in 2000 are reported.

Hurtgen, C

2001-04-01

42

Low-level Radioactivity Measurements  

International Nuclear Information System (INIS)

The objectives of the research performed in the area of low-level radioactivity measurements are (1) to maintain and develop techniques for the measurement of low-level environmental and biological samples, (2) to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters, alpha spectrometry), (3) to support and advise the nuclear and non-nuclear industry on problems of radioactive contamination and low-level radioactivity measurements; (4) to maintain and improve the quality assurance system according to the ISO17025 standard; and (5) to assess the internal dose from occupational intakes of radionuclides of workers of the nuclear industry. Progress and achievements in these areas in 2001 are reported

43

Multiple Sensors for Absolute Measurement of Aerobraking Spacecraft State Estimation  

Science.gov (United States)

Prior methods to determine the spacecraft state estimation for aerobraking have been radiometric tracking data and IMU measurement. We propose a novel method for real-time absolute measurement of full state estimation based on multiple sensors.

Pigneur, B.; Ariyur, K. B.

2014-06-01

44

Measurement of radioactivity in steel  

International Nuclear Information System (INIS)

Even after the control of scrap deliveries, there remains a small risk that the radioactive contaminated scrap passes the detecting devices. Therefore, the chemical laboratory takes a role to measure each heat for the absence of artificial radioactive nuclides with a gamma spectrometer equipped with NaI-detector. As the measurement must be performed in sequence with the steel production process, the allowable time for the measurement is quite limited. On the other hand, there could be still some possibility that background radiation might be present as the samples may contain some natural radioactivity. The task is how to differentiate the nature of radioactivity between naturally remaining radioactivity within safe limit and artificial nuclides present in the sample at a low level even though a very small amount of radioactivity could be detected in short time in both cases. We have set the alarm limit to 0.1 Bq/g for Co-60 as indicating nuclide. This limit is set more than 4 s (s = standard deviation) from the average background radiation. Therefore, false alarms are quite improbable. Strategy: The NaI gamma spectrometer performs a gross gamma measurement but it can not differentiate the nature of the nuclides present. If the alarm limit is hurt, the sample is measured on a high resolution gamma spectrometer with Ge-detector for identification of the gamma emitting nuclides. Calibration: Even though no appropriate international standards are adapted and no commercial measuring equipment is commercially available, the desired standard should contain Co-60 in the order of 1 to 100 Bq/g. The presence of other gamma emitting nuclides is desirable. In the Workshop we will present how to surmount this difficulty. (author)

45

Measurement Of Weak Radioactivity  

International Nuclear Information System (INIS)

This book is intended for scientists engaged in the measurement of weak alpha, beta, and gamma active samples; in health physics,environmental control, nuclear geophysics, tracer work, radiocarbon dating etc. It describes the underlying principles of radiation measurement and the detectors used. It also covers the sources of background, analyzes their effect on the detector and discusses economic ways to reduce the background. The most important types of low-level counting systems and the measurement of some of the more important radioisotopes are described here. In cases where more than one type can be used, the selection of the most suitable system is shown

46

Measurement of weak radioactivity  

CERN Document Server

This book is intended for scientists engaged in the measurement of weak alpha, beta, and gamma active samples; in health physics, environmental control, nuclear geophysics, tracer work, radiocarbon dating etc. It describes the underlying principles of radiation measurement and the detectors used. It also covers the sources of background, analyzes their effect on the detector and discusses economic ways to reduce the background. The most important types of low-level counting systems and the measurement of some of the more important radioisotopes are described here. In cases where more than one

Theodorsson, P

1996-01-01

47

Apparatus for measuring radioactive emissions  

International Nuclear Information System (INIS)

Apparatus for measuring radioactive emissions from moving radioactive material comprises at least one radiation detector in a housing serving as a first radiation shield and in which at least one groove is formed to expose at least a portion of a receptor surface of the detector. The groove extends transverse to the direction of movement of the material over the detector. A second radiation shield may be located between at least a portion of the first shield and the detector. The material of the second shield is inherently less contaminated and emits secondary excitation radiation of lower energy than the first material. (author)

48

Environmental radioactivity intercomparison measurements  

International Nuclear Information System (INIS)

In the context of the North Cotentin radioecological group set up in 1997 by the Ministry of the Environment and the Ministry of the Secretariat d'Etat a la Sante, the Swiss Federal Office of Public health, a national organization of independent status with respect to nuclear energy, conducted a series of measurements in the north Cotentin in 1998. Some sites proposed by local association 'Angry mothers' were examined in particular. This association has now taken the initiative to organize a large scale international intercomparison, ' North Cotentin 2000', in the vicinity of local nuclear installations. Besides the scientific aspect of the intercomparison, a specific aim of this intercomparison consists in providing to the local population with a real opportunity for direct exchange with participating international teams. The primary concern of the workshop is the determination, by in situ gamma spectrometry, of both natural and artificial concentrations and resulting ambient dose rates at selected marine ( beach) and terrestrial sites. A particular aim of the workshop also is to test the capacity of mobile teams to produce reliable results in the field of low level measurements on trace of special radionuclides (I129, Sr90, H3, C14, and alpha emitters) from environmental samples, using both direct ( in situ) and differed ( laboratory methods). an overview of the results obtained will be prepared for the benefit of the public. (N.C.)

49

Absolute Branching Fraction Measurements of Exclusive D^0 Semileptonic Decays  

CERN Document Server

With the first data sample collected by the CLEO-c detector at the psi(3770) resonance we have studied four exclusive semileptonic decays of the D0 meson. Our results include the first observation and absolute branching fraction measurement for D0 --> rho- e+ nu_e and improved measurements of the absolute branching fractions for D0 decays to K- e+ nu_e, pi- e+ nu_e, and K*- e+ nu_e.

Coan, T E; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G T; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Credé, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Pivarski, J; Phillips, E A; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stöck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Williams, J; Wiss, J; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z V; Seth, K K; Tomaradze, A G; Zweber, P; Ernst, J; Mahmood, A H; Severini, H; Asner, D M; Dytman, S A; Love, W; Mehrabyan, S S; Müller, J A; Savinov, V; Li, Z; López, A; Méndez, H; Ramírez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shibata, E I; Shipsey, I P J; Adams, G S; Chasse, M; Cravey, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Park, W; Thorndike, E H

2005-01-01

50

Absolute branching fraction measurements of exclusive D0 semileptonic decays.  

Science.gov (United States)

With the first data sample collected by the CLEO-c detector at the psi(3770) resonance we have studied four exclusive semileptonic decays of the D0 meson. Our results include the first observation and absolute branching fraction measurement for D0 --> p-e+ve and improved measurements of the absolute branching fractions for D0 decays to K-e+ve, pi-e+ve, and K*-e+ve. PMID:16383893

Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Crede, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Pivarski, J; Phillips, E A; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Williams, J; Wiss, J; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Mahmood, A H; Severini, H; Asner, D M; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shibata, E I; Shipsey, I P J; Adams, G S; Chasse, M; Cravey, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Park, W; Thorndike, E H

2005-10-28

51

Simple method for absolute activity measurement of 60Co source  

International Nuclear Information System (INIS)

The activity of 60Co source was measured using the full absorption, sum and random coincidence (pile-up) peaks and the total spectrum area. It is shown that if the true and random coincidences in the single detector are treated correctly, no additional data are needed for absolute source strength measurement. With the source on the detector end-cap (when the angular correlation effects are negligible), this simple method yields absolute activity values deviating from the reference activity by about 1%.

52

Radioactivity. Nuclear radiation and measured variables  

International Nuclear Information System (INIS)

The brochure on radioactivity covers the following issues: radioactivity and ionizing radiation (alpha, beta and gamma radiation), measuring unit for activity: Becquerel, measuring unit for radiation dosis: Sievert, radiation sources and radiation effects, radiation exposure by various radiation sources.

53

Absolute Neutron Emission Measurement in Burning Plasma Experiments  

Science.gov (United States)

The absolute measurement of neutron emission rate from the whole plasma is a very important diagnostics as a fusion power monitor in fusion experimental devices with D-T or D-T operations. Here measurement techniques of time-resolved and time-integrated absolute neutron emission on the present tokamaks and ITER are reviewed. In the present tokamaks, fission chamber installed outside the vacuum vessel are very popular in the absolute neutron emission rate measurement. As well as conventional neutron monitors installed outside the vacuum vessel, in-vessel neutron monitors using micro fission chamber are proposed for the absolute neutron emission rate measurement in ITER. The neutron activation system provides time-integrated measurements of the total neutron yield with high accuracy by using well known neutron reaction cross sections, which is useful to maintain a robust measure of fusion energy production with stability and wide dynamic range. The calibration of the relation between the neutron emission rate in the whole plasma and the output of neutron monitor is the most important issue in the absolute neutron emission rate measurements. The calibration of the neutron detectors has been performed by moving a neutron source such as a 252Cf neutron or a small accelerator-based neutron generator. For the calibration in ITER, the neutron generator with neutron emission rate of 1011 s-1 or stronger is required to obtain high accuracy.

Nishitani, Takeo; Ishikawa, Masao; Kondoh, Takashi; Kusama, Yoshinori; Asai, Keisuke; Sasao, Mmamiko

2008-03-01

54

Ion chambers simplify absolute intensity measurements in the vacuum ultraviolet  

Science.gov (United States)

Single or double ion chamber technique measures absolute radiation intensities in the extreme vacuum ultraviolet region of the spectrum. The ion chambers use rare gases as the ion carrier. Photon absorbed by the gas creates one ion pair so a measure of these is a measure of the number of incident photons.

Sampson, J. A. R.

1966-01-01

55

Absolute density measurements in the middle atmosphere  

Energy Technology Data Exchange (ETDEWEB)

In the last ten years a total of 25 sounding rockets employing ionization gauges have been launched at high latitudes ({proportional_to} 70 N) to measure total atmospheric density and its small scale fluctuations in an altitude range between 70 and 110 km. While the determination of small scale fluctuations is unambiguous, the total density analysis has been complicated in the past by aerodynamical disturbances leading to densities inside the sensor which are enhanced compared to atmospheric values. Here, we present the results of both Monte Carlo simulations and wind tunnel measurements to quantify this aerodynamical effect. The comparison of the resulting 'ram-factor' profiles with empirically determined density ratios of ionization gauge measurements and falling sphere measurements provides excellent agreement. This demonstrates both the need, but also the possibility, to correct aerodynamical influences on measurements from sounding rockets. We have determined a total of 20 density profiles of the mesosphere-lower-thermosphere (MLT) region. Grouping these profiles according to season, a listing of mean density profiles is included in the paper. A comparison with density profiles taken from the reference atmospheres CIRA86 and MSIS90 results in differences of up to 40%. This reflects that current reference atmospheres are a significant potential error source for the determination of mixing ratios of, for example, trace gas constituents in the MLT region. (orig.)

Rapp, M.; Luebken, F.J. [Leibniz Inst. of Atmospheric Physics, Kuehlungsborn (Germany); Gumbel, J. [Stockholm Univ. (Sweden). Dept. of Meteorology

2001-05-01

56

Absolute density measurements in the middle atmosphere  

Directory of Open Access Journals (Sweden)

Full Text Available In the last ten years a total of 25 sounding rockets employing ionization gauges have been launched at high latitudes ( ~ 70° N to measure total atmospheric density and its small scale fluctuations in an altitude range between 70 and 110 km. While the determination of small scale fluctuations is unambiguous, the total density analysis has been complicated in the past by aerodynamical disturbances leading to densities inside the sensor which are enhanced compared to atmospheric values. Here, we present the results of both Monte Carlo simulations and wind tunnel measurements to quantify this aerodynamical effect. The comparison of the resulting ‘ram-factor’ profiles with empirically determined density ratios of ionization gauge measurements and falling sphere measurements provides excellent agreement. This demonstrates both the need, but also the possibility, to correct aerodynamical influences on measurements from sounding rockets. We have determined a total of 20 density profiles of the mesosphere-lower-thermosphere (MLT region. Grouping these profiles according to season, a listing of mean density profiles is included in the paper. A comparison with density profiles taken from the reference atmospheres CIRA86 and MSIS90 results in differences of up to 40%. This reflects that current reference atmospheres are a significant potential error source for the determination of mixing ratios of, for example, trace gas constituents in the MLT region.

Key words. Middle atmosphere (composition and chemistry; pressure, density, and temperature; instruments and techniques

M. Rapp

57

Measurements of Absolute Abundances in Solar Flares  

CERN Document Server

We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory (SDO). EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias ($f$). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature, it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is $...

Warren, Harry P

2013-01-01

58

Absolute density measurements in the middle atmosphere  

OpenAIRE

In the last ten years a total of 25 sounding rockets employing ionization gauges have been launched at high latitudes ( ~ 70° N) to measure total atmospheric density and its small scale fluctuations in an altitude range between 70 and 110 km. While the determination of small scale fluctuations is unambiguous, the total density analysis has been complicated in the past by aerodynamical disturbances leading to densities inside the sensor which are enhanced compared to atmospheric values...

Rapp, M.; Gumbel, J.; -j Lu?bken, F.

2001-01-01

59

Measurements of Absolute Abundances in Solar Flares  

OpenAIRE

We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory (SDO). EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the p...

Warren, Harry P.

2013-01-01

60

Absolute Abundance Measurements in Solar Flares  

Science.gov (United States)

We present measurements of elemental abundances in solar flares with EVE/SDO and EIS/Hinode. EVE observes both high temperature Fe emission lines Fe XV-XXIV and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (F). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is F=1.17+-0.22. Furthermore, we have compared the EVE measurements with corresponding flare observations of intermediate temperature S, Ar, Ca, and Fe emission lines taken with EIS. Our initial calculations also indicate a photospheric composition for these observations. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation in the non-flaring corona occurs.

Warren, Harry

2014-06-01

61

Measurements of Absolute Abundances in Solar Flares  

Science.gov (United States)

We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory. EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (f). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature, it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is f = 1.17 ± 0.22. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation occurs.

Warren, Harry P.

2014-05-01

62

Measuring absolute blood pressure using microbubbles.  

Science.gov (United States)

Gas microbubbles are highly compressible, which makes them very efficient sound scatterers. As another consequence of their high compressibility, the radii of the microbubbles are affected by the pressure of the fluid around them, which changes their resonance frequency. Although the pressures present within the human body cause only minor variations in the radii of uncoated microbubbles (?0.2% per 10 mmHg) and, therefore, very small variations in the resonance frequency (?1 kHz per 10 mmHg), it was found in the work described here, through both simulations and in vitro measurements, that large changes in resonance frequency can occur in phospholipid-coated microbubbles for small blood pressure variations because of the exotic buckling dynamics of phospholipid monolayers (up to 240 kHz per 10 mmHg). This method should allow non-invasive measurement of the gauge blood pressure in deep blood vessels as long as the microbubble physical properties are well controlled. PMID:24433747

Tremblay-Darveau, Charles; Williams, Ross; Burns, Peter N

2014-04-01

63

Effects of natural radioactivity on food radioactivity measurement  

International Nuclear Information System (INIS)

Since the accident of the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Company, groups and individuals including local governments, food manufacturers, distribution circles, retail circles, and citizens are eager to measure the radioactivity of food, in order to confirm the safety of food from the concerns about radioactive contamination. The measurement of radioactivity of food is done by quantitatively determining gamma rays due to radioactive cesium that was incorporated into the biosphere cycle after having been released into the environment. As for the radioactivity measurement of food using gamma-ray spectrometry with a potassium iodide scintillation detector, which is very commonly used, this paper describes the handling method of obtained data, the principle of erroneous detection of radioactive cesium and iodine interrupted by natural radionuclides, and countermeasures for it. Major natural radioactivity sources are uranium series and thorium series. This paper explains gamma rays, which are characteristic in the decay process of uranium series and often affect the measurement of radioactive cesium in food and water. (O.A.)

64

Absolute Branching Fraction Measurements of Exclusive D^+ Semileptonic Decays  

CERN Document Server

Using data collected at the psi(3770) resonance with the CLEO-c detector at the Cornell e+e- storage ring, we present improved measurements of the absolute branching fractions of D+ decays to K0B e+ nu_e, pi0 e+ nu_e, K0B* e+ nu_e, and rho0 e+ nu_e, and the first observation and absolute branching fraction measurement of D+ --> omega e+ nu_e. We also report the most precise tests to date of isospin invariance in semileptonic D0 and D+ decays.

Huang, G S; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Chasse, M; Cravey, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Park, W; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G T; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Credé, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Weaver, K M; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stöck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Williams, J; Wiss, J; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z V; Seth, K K; Tomaradze, A G; Zweber, P; Ernst, J; Mahmood, A H; Severini, H; Asner, D M; Dytman, S A; Love, W; Mehrabyan, S S; Müller, J A; Savinov, V; Li, Z; López, A; Méndez, H; Ramírez, J

2005-01-01

65

Absolute branching fraction measurements of exclusive D+ semileptonic decays.  

Science.gov (United States)

Using data collected at the psi(3770) resonance with the CLEO-c detector at the Cornell e+e- storage ring, we present improved measurements of the absolute branching fractions of D+decays to K0e+ve, pi0e+ve, K*0e+ve, and p0e+ve, and the first observation and absolute branching fraction measurement of D+ --> omega e+ve. We also report the most precise tests to date of isospin invariance in semileptonic D0 and D+ decays. PMID:16383892

Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Chasse, M; Cravey, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Park, W; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Crede, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Weaver, K M; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Williams, J; Wiss, J; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Mahmood, A H; Severini, H; Asner, D M; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J

2005-10-28

66

On the Choice of Absolute or Relative Inequality Measures  

OpenAIRE

Context: In a recent article in this journal, Sam Harper and his colleagues (2010) call for increased awareness and open dialogue of moral judgments underlying health inequality measures. They recommend that analysts use relative inequality measures when concerned only about health inequality but use absolute inequality measures when also concerned about other issues, such as the overall level of population health and the level of health for each group in the population.

Asada, Yukiko

2010-01-01

67

Quality Assurance In Radioactivity Measurements  

International Nuclear Information System (INIS)

The credibility of obtained results is ensured by the quality assurance and control. The main requisitions involved in the quality assurance of the laboratory according to the requirements of LVS EN ISO/IEC 17025:2005 are: 1) the use of calibrated equipment only; 2) the regular and long-time use of reference materials in the control of equipment; 3) the estimation of uncertainty sources and determination of uncertainties within the given interval of credibility; 4) the validation and verification. The very important requirement is regular participation in the interlaboratory intercomparison exercises that makes it possible to estimate and find possible error sources and carry out the corrective actions. The measurements of the radioactivity of Cs-137, Co-60, H-3, the natural radioactive nuclides as well as other radionuclides in different environmental (soil, precipitation, different types of water, needles, et al.) samples, and in various radioactive polluted objects are carried out in the Laboratory of Radiation physics. The quality assurance system was implemented in our laboratory in 2000. Since 1999 laboratory is regular participant in the interlaboratory intercomparison exercises, organized by the RISO National Laboratory (Denmark) and IAEA (Vienna). The paper shows the laboratory's system of quality assurance and its implementation. We have the internal quality audit program that takes into account the requirements of LVS EN ISO/IEC 17025: 2005, but the main atVS EN ISO/IEC 17025: 2005, but the main attention is paid to the intercomparison of the results of analyses of laboratories, their evaluation and interpretation. Only credible and justified results can be the basis for further use in any field, thus making it possible to make legitimate decisions. (Authors)

68

Preparation and absolute measurement of 141Ce standard solution  

International Nuclear Information System (INIS)

This paper describes in detail the preparation of 141Ce standard solution with enriched 140Ce target (99.4%) and the absolute measurement of 141Ce disintegration rate by 4??-? coincident method. The overall uncertainty of the standard solution is ± 1%

69

Absolute surface coverage measurement using a vibrational overtone  

Science.gov (United States)

Determination of absolute surface coverage with sub-monolayer sensitivity is demonstrated using evanescent-wave cavity ring-down spectroscopy (EW-CRDS) and conventional CRDS by employing conservation of the absolute integrated absorption intensity between gas and adsorbed phases. The first C-H stretching overtones of trichloroethylene (TCE), cis-dichloroethylene, and trans-dichloroethylene are probed using the idler of a seeded optical parametric amplifier having a 0.075 cm-1 line width. Polarized absolute adsorbate spectra are obtained by EW-CRDS using a fused-silica monolithic folded resonator having a finesse of 28 500 at 6050 cm-1, while absolute absorption cross sections for the gas-phase species are determined by conventional CRDS. A measure of the average transition moment orientation on the surface, which is utilized for the coverage determination, is derived from the polarization anisotropy of the surface spectra. Coverage measurement by EW-CRDS is compared to a mass-spectrometer-based surface-uptake technique, which we also employ for coverage measurements of TCE on thermally grown SiO2 surfaces. To assess the potential for environmental sensing, we also compare EW-CRDS to optical waveguide techniques developed previously for TCE detection.

Pipino, Andrew C. R.; Hoefnagels, Johan P. M.; Watanabe, Noboru

2004-02-01

70

Beam energy absolute measurement using K-edge absorption spectrometers  

International Nuclear Information System (INIS)

A method is presented of absolute energy measurement with an accuracy of triangle ? ? 10-4?o by direct measurement of the bend angle in a high-precision magnetic dipole using two opposite-direction short (about 2 mm long) high-field-intensity magnets (bar ? dipole much-lt ?shortmag) installed at each end and two K-edge absorption spectrometers. Using these spectrometers and the hard x-ray synchrotron radiation created by the short magnets, a bend angle of 4.5 arc deg for the CEBAF energy bandwidth can be measured with an accuracy of a few units of 10-6 rad, and the main sources of systematic errors are the absolute measurement of the field integral and the determination of the centroid of the synchrotron beam at a wavelength equal to the K-edge absorption of the chosen substance

71

Measurement of radioactivity in water samples  

International Nuclear Information System (INIS)

Public concern about the levels of radioactivity release to the environment whether authorised discharges or resulting from nuclear accident, has increased in recent years. Consequently there is increasing pressure for reliable data on the distribution of radioactivity and the extent of its intrusion into food chains and water supplies. As a result a number of laboratories not experienced in radioactivity measurements have acquired nucleonic counting equipment. These notes explore the underlying basics and indicate sources of essential data and information which are required for a better understanding of radioactivity measurements. Particular attention is directed to the screening tests which are usually designated ''gross'' alpha and ''gross'' beta activity measurement. (author)

72

Absolute gravity acceleration measurement in atomic sensor laboratories  

Science.gov (United States)

This paper reports the results from the accurate measurement of the acceleration of gravity g taken at two separate premises in the Polo Scientifico of the Florence University (Italy). In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the measurement of forces with high spatial resolution are in progress. Both experiments require an independent knowledge on the local value of g. Gravity measurements were conducted using an FG5 absolute gravimeter, and accompanied by seismic recordings for evaluating the noise condition at the site. The absolute accelerations of gravity at the two laboratories are ( 980 492 160.6 ± 4.0) ?Gal and ( 980 492 048.3 ± 3.0) ?Gal for the European Laboratory for Non-Linear Spectroscopy (LENS) and Dipartimento di Fisica e Astronomia, respectively. Other than for the two referenced experiments, the data here presented will serve as a benchmark for any future study requiring an accurate knowledge of the absolute value of the acceleration of gravity in the study region.

de Angelis, M.; Greco, F.; Pistorio, A.; Poli, N.; Prevedelli, M.; Saccorotti, G.; Sorrentino, F.; Tino, G. M.

2012-03-01

73

An absolute measurement of #-v# of Cf252  

International Nuclear Information System (INIS)

An absolute measurement of v of Cf252. An absolute determination of the average number of neutrons, #-v#, emitted in the spontaneous fission of Cf252 has been made by counting the fission neutrons in a large liquid scintillator. The detection efficiency of this counter was measured as a function of neutron energy. Well-collimated neutrons were scattered into the scintillator by an anthracene crystal, which detected the corresponding recoil protons. Pulse-shape discrimination was employed to eliminate ?-ray background. The detection efficiency for Cf252 fission neutrons was found to be 0.703 ± 0.007, giving a value of 3.78 ± 0.04 for the average number of prompt neutrons emitted per Cf252 fission. (author)

74

Measurement uncertainty of radioactivity secondary standard of radionuclides 60 Co and 22 Na  

International Nuclear Information System (INIS)

The secondary standard for radioactivity of radionuclides 60 Co and 22 Na was realised by 'sum-peak' method using scintillation Na(Tl) detector. 'Sum-peak' method is one of absolute methods for radioactivity determination of some radionuclides. In this paper the basic concept of 'sum-peak' method and measurement uncertainty of radioactivity secondary standard of radionuclides 60 Co and 22 Na are presented. (author)

75

Measurement of the absolute branching fraction of the Ds+- meson  

CERN Document Server

The Ds+- -> K+-K-+pi+- absolute branching fraction is measured using e+e- -> Ds*+- Ds1-+(2536) events collected by the Belle detector at the KEKB e+e- asymmetric energy collider. Using the ratio of yields when either the Ds1 or Ds* is fully reconstructed, we find Br(Ds+- -> K+-K-+pi+-)= (4.0+-0.4(stat)+-0.4(sys))%.

Abe, K; Dragic, J; Fujii, H; Gershon, T; Haba, J; Hazumi, M; Higuchi, T; Igarashi, Y; Itoh, R; Iwasaki, Y; Katayama, N; Kichimi, H; Krokovnyi, P P; Limosani, A; Nakamura, I; Nakao, M; Nakazawa, H; Nishida, S; Nozaki, T; Ozaki, H; Ronga, F J; Saitoh, S; Sakai, Y; Stamen, R; Sumisawa, K; Suzuki, S Y; Tajima, O; Takasaki, F; Tamai, K; Tanaka, M; Trabelsi, K; Tsuboyama, T; Tsukamoto, T; Uehara, S; Unno, Y; Uno, S; Ushiroda, Y; Yamauchi, M; Zhang, J; Hoshi, Y; Neichi, K; Aihara, H; Hastings, N C; Ishikawa, A; Itoh, K; Iwasaki, M; Kakuno, H; Kusaka, A; Nakahama, Y; Tanabe, K; Anipko, D; Arinstein, K; Aulchenko, V; Bedny, I; Bondar, A; Eidelman, S; Epifanov, D A; Gabyshev, N; Kuzmin, A; Poluektov, A; Root, N; Shwartz, B; Sidorov, V; Usov, Yu; Zhilich, V; Aoki, K; Enari, Y; Hara, K; Hayasaka, K; Hokuue, T; Iijima, T; Ikado, K; Inami, K; Kishimoto, N; Kozakai, Y; Kubota, T; Miyazaki, Y; Ohshima, T; Okabe, T; Sato, N; Senyo, K; Yoshino, S; Arakawa, T; Kawasaki, T; Miyata, H; Tamura, N; Watanabe, M; Asano, Y; Aso, T; Aushev, T; Bay, A; Hinz, L; Jacoby, C; Schietinger, T; Schneider, O; Villa, S; Wicht, J; Zürcher, D; Aziz, T; Banerjee, S; Gokhroo, G; Majumder, G; Bahinipati, S; Drutskoy, A; Goldenzweig, P; Kinoshita, K; Kulasiri, R; Sayeed, K; Schwartz, A J; Somov, A; Bakich, A M; Cole, S; McOnie, S; Parslow, N; Peak, L S; Stöck, H; Varvell, K E; Yabsley, B D; Balagura, V; Chistov, R; Danilov, M; Liventsev, D; Medvedeva, T; Mizuk, R; Pakhlov, P; Pakhlova, G; Tikhomirov, I; Uglov, T; Tian, Y BanX C; Barberio, E; Dalseno, J; Dowd, R; Moloney, G R; Sevior, M E; Taylor, G N; Tse, Y F; Urquijo, P; Barbero, M; Browder, T E; Guler, H; Jones, M; Li, J; Nishimura, K; Olsen, S L; Peters, M; Rorie, J; Sahoo, H; Uchida, K; Varner, G; Belous, K S; Shapkin, M; Sokolov, A; Bitenc, U; Bizjak, I; Fratina, S; Gorisek, A; Pestotnik, R; Staric, M; Zupanc, A; Blyth, S; Chen, A; Chen, W T; Go, A; Hou, S; Kuo, C C; Bozek, A; Kapusta, P; Lesiak, T; Matyja, A; Natkaniec, Z; Ostrowicz, W; Palka, H; Rózanska, M; Wiechczynski, J; Bracko, M; Korpar S; Brodzicka, J; Chang, M C; Kikuchi, N; Mikami, Y; Nagamine, T; Schonmeier, P; Yamaguchi, A; Yamamoto, H; Chang, P; Chao, Y; Chen, K F; Hou, W S; Hsiung, Y B; Lee, Y J; Lin, C Y; Lin, S W; Shen, Y T; Tsai, Y T; Ueno, K; Wang, C C; Wang, M Z; Wu, C H; Cheon, B G; Choi, J H; Ha, H; Kang, J S; Won, E; Choi, S K; Choi, Y; Choi, Y K; Kim, H O; Kim, J H; Park, C W; Park, K S; Chuvikov, A; Garmash, A; Marlow, D; Ziegler, T; Dash, M; Mohapatra, D; Piilonen, L E; Yusa, Y; Fujikawa, M; Hayashii, H; Imoto, A; Kataoka, S U; Miyabayashi, K; Noguchi, S; Krizan, P; Golob, B; Seidl, R; Grosse-Perdekamp, M; Hara, T; Heffernan, D; Miyake, H; Hasegawa, Y; Satoyama, N; Takada, N; Nitoh, O; Hoshina, K; Ishino, H; Khan, H R; Kibayashi, A; Mori, T; Ono, S; Watanabe, Y; Iwabuchi, M; Kim, Y J; Liu, Y; Sarangi, T R; Uchida, Y; Kang, J H; Kim, T H; Kwon, Y J; Kurihara, E; Kawai, H; Park, H; Kim, H J; Kim, S K; Lee, J; Lee, S E; Yang He Young; Kumar, R; Singh, J B; Soni, N; Lange, J S; Leder, G; MacNaughton, J; Mandl, F; Mitaroff, W A; Pernicka, M; Schwanda, C; Widhalm, L; Matsumoto, T; Nakagawa, T; Seki, T; Sumiyoshi, T; Yamamoto, S; Müller, J; Murakami, A; Sugiyama, A; Suzuki, S; Nagasaka, Y; Nakano, E; Sakaue, H; Teramoto, Y; Ogawa, A; Shibuya, H; Ogawa, S; Okuno, S; Sakamoto, H; Wang, C H; Schümann, J; Stanic, S; Xie, Q L; Yuan, Y; Zang, S L; Zhang, C C; Yamashita, Y; Zhang, L M; Zhang, Z P

2006-01-01

76

A quantitative PCR method for measuring absolute telomere length  

OpenAIRE

Abstract We describe a simple and reproducible method to measure absolute telomere length (aTL) using quantitative real-time polymerase chain reaction (qPCR). This method is based on the Cawthon method for relative measurement of telomere length (TL) but modified by introducing an oligomer standard to measure aTL. The method describes the oligomer standards, the generation of the standard curve and the calculations required to calculate aTL from the qPCR data. The necessary controls...

Fenech Michael; O'Callaghan Nathan J

2011-01-01

77

Measurement of absolute photoluminescence quantum efficiencies in conjugated polymers  

Science.gov (United States)

Measurements of absolute photoluminescence (PL) efficiencies have been performed for solid films of several conjugated polymers commonly used for electroluminescence. In poly( p-phenylenevinylene) (PPV), a PL efficiency of 0.27 is measured in samples which show an initial PL decay time-constant of 320 ps. These values indicate that photoexcitation in PPV produces intra-chain singlet excitons with a high quantum yield. The PL efficiencies of derivatives of PPV have been investigated, and efficiencies in excess of 0.4 have been measured for cyano-substituted PPVs.

Greenham, N. C.; Samuel, I. D. W.; Hayes, G. R.; Phillips, R. T.; Kessener, Y. A. R. R.; Moratti, S. C.; Holmes, A. B.; Friend, R. H.

1995-07-01

78

Measurement of gamma radioactivity in steel  

International Nuclear Information System (INIS)

The steel industry is being confronted increasingly with radioactive scrap from dismantled nuclear facilities. The clearance and release regulations that exist around the world differ very greatly and are difficult to implement. A 'radioactivity measurement' working group has therefore been set up at VDEh to clarify how radioactive measurements can be integrated into the day-to-day production routine. Operating results obtained at Thyssen Krupp Stahl AG with a gamma-ray spectrometer indicate a possibility for the simple detection of radioactive contamination. (orig.)

79

Absolute measurements of photoionization cross-sections for ions  

International Nuclear Information System (INIS)

A merged-beam set-up for absolute measurements of photoionization cross-sections of ions is described. The facility is capable of recording cross-sections as low as 10-19 cm2 and has been used to study a large number of singly- and multiply-charged, atomic and molecular, positive and negative ions. It is based on a synchrotron radiation beam line fitted with an undulator at the storage ring ASTRID and a low-energy (?2 keV) ion beam line. Photons in the energy range 15-200 eV are merged co-linearly with the target ions over a distance of 50 cm, and the absolute photoionization cross-section is determined from the resulting photoion yield with a typical accuracy of 10%. Different types of ion sources are available, thus permitting a large number of positive and negative, atomic and molecular, singly- and multiply-charged ions to be investigated. Emphasis is put on accurate determination of the absolute cross-sections, requiring calibration of photodiode and particle detectors together with measurements of the photon-ion overlap

80

A method to measure the absolute branching fractions of decays  

Science.gov (United States)

It is proposed to exploit the decay of the meson and of its charge conjugate copiously produced at LHC to obtain a sample of baryons through the strong decay . The sample thus obtained is not affected by biases typically introduced by selections that depend on specific decay modes. Therefore it allows a measurement of the absolute branching fraction for the decay of the baryon into or into other observable final states to be performed in a model independent manner. The accuracy that can be achieved with this method is discussed and it is shown that it would be either competitive with or an improvement over current measurements.

Contu, A.; Fonnesu, D.; Oldeman, R. G. C.; Saitta, B.; Vacca, C.

2014-12-01

81

Absolute measurements of photon emission probabilities of 169Yb  

International Nuclear Information System (INIS)

A solution of 169Yb was absolutely standardized by the 4?(EC,X)-? coincidence counting method and the result was used to obtain direct measurements of gamma-ray emission probabilities with a coaxial HPGe detector. The empirical relation proposed by (Vano, F., Gonzalez, L., Gaeta R., Gonzalez, J.A., 1975. An empirical function which relates the slope of the Ge efficiency curves and the active volume Nucl. Instr. Meth. 123, 573) was tested using the gamma spectral response above 200 keV. The half-life of 169Yb was also measured with a 4?? ionization chamber

82

Absolutely Continuous Invariant Measures of Piecewise Linear Lorenz Maps  

OpenAIRE

Consider piecewise linear Lorenz maps on $[0, 1]$ of the following form \\[ f_{a,b,c}(x)= {ll} ax+1-ac & x \\in [0, c) b(x-c) & x \\in (c, 1].\\] We prove that $f_{a,b,c}$ admits an absolutely continuous invariant probability measure (acim) $\\mu$ with respect to the Lebesgue measure if and only if $f_{a,b,c}(0) \\le f_{a,b,c}(1)$, i.e. $ac+(1-c)b \\ge 1$. The acim is unique and ergodic unless $f_{a,b,c}$ is conjugate to a rational rotation. The equivalence between the acim and the...

Ding, Yi Ming; Fan, Ai Hua; Yu, Jing Hu

2010-01-01

83

Measurement of absolute lung density by Compton-scatter densitometry  

International Nuclear Information System (INIS)

The non-invasive determination of absolute lung density would be of great importance if it could be used in the evaluation of patients with pulmonary edema. To obtain this measurement, we have developed a portable densitometer using CdTe room-temperature detectors, compact collimators made of tantalum tubes and a 153Gd source. System response in the density range of 0.1 to 1 g/cm3 is linear. Variations in the absorption paths of up to 8 cm of lucite do not produce significant changes on measured density values

84

Absolute measurement of 99mTc activity  

International Nuclear Information System (INIS)

The experimental technique and results of 99mTc absolute activity measurement by 4 Pi beta-gamma coincidence method are described. The detection efficiency of 99mTc gamma rays (2.12, 140.5 and 142.6 KeV) and their internal conversion electrons in 4 Pi beta counter as a function of the VYNS foil thickness is measured. It is obtained that after complete absorption of 2.12 KeV gamma ray by the foils, the contribution from each 99mTc decay to the beta in 4 Pi beta counter is 0.1117 +- 0.0005

85

Absolute and specific measures of research group excellence  

CERN Document Server

A desirable goal of scientific management is to introduce, if it exists, a simple and reliable way to measure the scientific excellence of publicly-funded research institutions and universities to serve as a basis for their ranking and financing. While citation-based indicators and metrics are easily accessible, they are far from being universally accepted as way to automate or inform evaluation processes or to replace evaluations based on peer review. Here we consider absolute measurements of research excellence at an amalgamated, institutional level and specific measures of research excellence as performance per head. Using biology research institutions in the UK as a test case, we examine the correlations between peer-review-based and citation-based measures of research excellence on these two scales. We find that citation-based indicators are very highly correlated with peer-evaluated measures of group strength but are poorly correlated with group quality. Thus, and almost paradoxically, our analysis indi...

Mryglod, O; Holovatch, Yu; Berche, B

2012-01-01

86

An absolute scale for measuring the utility of money  

Science.gov (United States)

Measurement of the utility of money is essential in the insurance industry, for prioritising public spending schemes and for the evaluation of decisions on protection systems in high-hazard industries. Up to this time, however, there has been no universally agreed measure for the utility of money, with many utility functions being in common use. In this paper, we shall derive a single family of utility functions, which have risk-aversion as the only free parameter. The fact that they return a utility of zero at their low, reference datum, either the utility of no money or of one unit of money, irrespective of the value of risk-aversion used, qualifies them to be regarded as absolute scales for the utility of money. Evidence of validation for the concept will be offered based on inferential measurements of risk-aversion, using diverse measurement data.

Thomas, P. J.

2010-07-01

87

Absolute measurements of chlorine Cl+ cation single photoionization cross section  

Science.gov (United States)

The photoionization of Cl+ leading to Cl2+ was measured in the photon energy range of 19.5-28.0 eV. A spectrum with a photon energy resolution of 15 meV normalized to absolute cross-section measurements is presented. The measurements were carried out by merging a Cl+ ion beam with a photon beam of highly monochromatic synchrotron radiation at the Advanced Light Source at Lawrence Berkeley National Laboratory. The measured photoionization of Cl+ consists of several autoionization resonances surperimposed on the direct photoionization signal. Most of the prominent resonances are assigned to members of Rydberg series originating from the singlet ground state and from metastable triplet levels within the ground-state configuration of Cl+. The direct ionization cross section is no larger than 12 Mb.

Hernández, E. M.; Juárez, A. M.; Kilcoyne, A. L. D.; Aguilar, A.; Hernández, L.; Antillón, A.; Macaluso, D.; Morales-Mori, A.; González-Magaña, O.; Hanstorp, D.; Covington, A. M.; Davis, V.; Calabrese, D.; Hinojosa, G.

2015-01-01

88

Absolute measurement of hadronic branching fractions of the Ds+ meson.  

Science.gov (United States)

The branching fractions of D(s)(+/-) meson decays serve to normalize many measurements of processes involving charm quarks. Using 298 pb(-1) of e(+)e(-) collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for eight D(s)(+/-) decays with a double tag technique. In particular we determine the branching fraction B(D(s)(+)-->K(-)K(+}pi(+))=(5.50+/-0.23+/-0.16)%, where the uncertainties are statistical and systematic, respectively. We also provide partial branching fractions for kinematic subsets of the K(-)K(+)pi(+) decay mode. PMID:18518186

Alexander, J P; Berkelman, K; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Libby, J; Powell, A; Wilkinson, G; Ecklund, K M; Love, W; Savinov, V; Lopez, A; Mendez, H; Ramirez, J; Ge, J Y; Miller, D H; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Rademacker, J; Asner, D M; Edwards, K W; Naik, P; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L

2008-04-25

89

Absolute Measurement of Hadronic Branching Fractions of the Ds+ Meson  

International Nuclear Information System (INIS)

The branching fractions of Ds± meson decays serve to normalize many measurements of processes involving charm quarks. Using 298 pb-1 of e+e- collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for eight Ds± decays with a double tag technique. In particular we determine the branching fraction B(Ds+?K-K+?+)=(5.50±0.23±0.16)%, where the uncertainties are statistical and systematic, respectively. We also provide partial branching fractions for kinematic subsets of the K-K+?+ decay mode

90

High-precision absolute measurement of CEBAF beam mean energy  

International Nuclear Information System (INIS)

The absolute measurement of the beam mean energy with an accuracy of one part in 104 or higher is an important demand of the CEBAF Hall A physics program. This accuracy may reduce the uncertainty in the d(e, e'p)p cross section ??/? to 1%. The need for such an accurately calibrated beam is not particular to CEBAF; at other electron facilities uncertainty in the incident energy has proven to be among the dominant sources of systematic error. The following methods for solving the problem were considered at both CEBAF and the Yerevan Physics Institute during 1990--1991: Backscattering of a plane electromagnetic wave by the relativistic electron beam. Calculations show that the intensity of the backscattered radiation in a bandwidth of 10-4 near the maximum frequency is about 1 photon per second at 4 GeV and 0.3 mA. Magnetic spectrometers performing as three- and four-magnet chicanes with appropriate detector systems. Such a system was used at SLAC for absolute measurement of the SLC beams energy, where a maximum accuracy of 5 x 10-4 was achieved. Calculations show that a similar accuracy can be achieved for the CEBAF beam in both proposed systems. Measurement of the vertical distribution of synchrotron radiation. Calculations indicate that precision of about 2.5 x 10-5 is achievable for CEBAF

91

Full field imaging based instantaneous hyperspectral absolute refractive index measurement  

Energy Technology Data Exchange (ETDEWEB)

Multispectral refractometers typically measure refractive index (RI) at discrete monochromatic wavelengths via a serial process. We report on the demonstration of a white light full field imaging based refractometer capable of instantaneous multispectral measurement of absolute RI of clear liquid/gel samples across the entire visible light spectrum. The broad optical bandwidth refractometer is capable of hyperspectral measurement of RI in the range 1.30 1.70 between 400nm 700nm with a maximum error of 0.0036 units (0.24% of actual) at 414nm for a = 1.50 sample. We present system design and calibration method details as well as results from a system validation sample.

Baba, Justin S [ORNL; Boudreaux, Philip R [ORNL

2012-01-01

92

Absolute ball bearing wear measurements from SSME turbopump dynamic signals  

Science.gov (United States)

This paper describes how absolute ball bearing wear is measured in an operating turbopump from heavily loaded ball bearing vibration signatures. This technique was developed during testing of the High Pressure Oxygen Turbopump (HPOTP) of the Space Shuttle Main Engine (SSME). A linear correlation was established between the cage frequency harmonic amplitudes on internal strain gages and the measured ball wear from pump disassembly. In a manner similar to that used by Sunnersjö [1] for lightly loaded roller bearings, the dominant cage harmonics in the vibration spectra were shown to correspond to those of a Fourier series representation of the circumferential ball diameter variation or wear pattern. Strain gages and accelerometers on the external pump casing also show similar wear symptoms. These external measurements allow convenient wear monitoring for pre-flight testing of the SSME.

Hine, M. J.

1989-01-01

93

Improvement of a cryogenic radiometer for XFEL absolute intensity measurement  

International Nuclear Information System (INIS)

A cryogenic radiometer was improved for measurements of the absolute radiant power of x-ray Free Electron Laser, which provides intense radiation with an ultra-short pulse duration. Based on simulation results obtained by the Monte Carlo program EGS 5 code, a new cavity absorber of the cryogenic radiometer was developed. The simulation results show that the new cavity absorber achieves absorptance close to unity for hard x-rays up to photon energies of 40 keV. The excellent performance of the new cavity absorber, as well as the consistency between the new and the former cavity, was confirmed by calibrating two different types of silicon photodiodes. The calibration results agreed well within their relative expanded uncertainties. To confirm the performance of the new cavity absorber in the high radiant power region, the radiant powers obtained with the cryogenic radiometer and an x-ray beam monitor were also compared. A strong correlation between the two detectors was obtained. With the new cavity absorber, the absolute radiant power of XFEL for photon energies of up to 40 keV with low uncertainties is expected to be measured.

94

Fractal Methods in Radioactivity Measurements.  

Science.gov (United States)

This work is in the category of applications of physics. We describe a concept of Minkowski volume (sausage) and show how an expectation value of a physical process can be calculated on a fractal object. These concepts are applied to the radioactivity in nature. The Minkowski volume is used to study the distribution of ^238U and ^232Th radioactive series as well as ^40K in environmental particles such as soils and coal fly ash.(T.M. Semkow, Environ. Intern. (1996) to be published.) The surface and internal radioactivity concentrations are obtained from the fits to experimental data, in addition to the fractal dimensions of the surfaces and thicknesses of the surface layers. We also study ^222Rn emanation from solid materials and show that the radon emanating power is proportional to V(R), where V is the Minkowski volume and R is the ?-recoil range from the decay of ^226Ra, if Ra is distributed uniformly in the solid. (T.M. Semkow, Phys. Rev. Lett. 66 (1991) 3012.) The dependence of emanating power on surface roughness and Ra distribution is also discussed.

Semkow, Thomas M.

1996-10-01

95

Radioactivity measurement of 3H-labeled gas with position-sensitive proportional counter  

International Nuclear Information System (INIS)

A new principle using a position-sensitive proportional counter with a partially resistive anode wire is proposed for absolute radioactivity measurement of 3H-labeled gas. The new method can eliminate the influence of end effect and can define the effective counting volume which makes it possible to measure the absolute or specific activity of radioactive gas. In addition to the description of the new principle, the method to make a partially resistive anode wire and the characteristics of the wire are mentioned. (author)

96

Absolute measurements of Co-60 and Au-198 by #betta#-#betta# coincidence method  

International Nuclear Information System (INIS)

This paper described the absolute measurement of the radioactivity by the beta-gamma coincidence method. The disintegration rates have been measured for two Co-60 samples and two types of thermal neutron irradiated gold foils. The measurement system consists of a gamma-ray detection channel with a NaI(Tl) scintillator of 50.8mm in diameter and 50.8mm in length, a beta-ray detection channel with a plastic scintillator of 50.8mm in diameter and 2.0mm in thickness, and a fast coincidence circuit. With this system the activities of the Co-60 and Au-198 have been determind with an acuracy better than 1.5%. (author)

97

Absolute measurements of the thermal neutron flux by the foil activation method using the 4??-? coincidence technique  

International Nuclear Information System (INIS)

An analysis of the correction factors required for the ?-? coincidence method is presented together with a listing of the various formulae involved in the determination of radioactive sources. The detection system including the activation detectores are described and the results are shown for the absolute measurements of thermal neutron flux carried out in the core of the Argonaut Reactor, at Instituto de Engenharia Nuclear (IEN), Brazil. (Author)

98

National and international traceability in radioactivity measurements  

International Nuclear Information System (INIS)

The quality of radioactivity measurements in this period of rapidly expanding production and use of radioactive materials and their transfer to the biosphere has come under increasing scrutiny from government regulatory agencies and the public alike. This paper reviews the history and present status of measurements assurance, or traceability, programmes developed in the United States of America to ensure the quality of such measurements. It also briefly describes intercomparative measurements carried out with other national laboratories either directly or through the Bureau International des Poids et Mesures and the International Atomic Energy Agency for the purpose of establishing traceability in the international field. It is concluded that in the USA it is logistically impossible, except in a few special cases, for the National Bureau of Standards to provide other than programmes that will give implicit quality assurance for radioactivity measurements. (author)

99

Absolute measurement of neutron fluxes inside the reactor core  

International Nuclear Information System (INIS)

The subject of this work is the development and study of two methods of neutron measurements in nuclear reactors, the new method of high neutron flux measurements and the Li6-semiconductor neutron spectrometer. This work is presented in four sections: Section I. The introduction explains the need for neutron measurements in reactors. A critical survey is given of the existing methods of high neutron flux measurement and methods of fast neutron spectrum determination. Section II. Theoretical basis of the work of semiconductor counters and their most important characteristics are given. Section III. The main point of this section is in presenting the basis of the new method which the author developed, i.e., the long-tube method, and the results obtained by it, with particular emphasis on absolute measurement of high neutron fluxes. Advantages and limitations of this method are discussed in details at the end of this section. Section IV. A comparison of the existing semiconductor neutron spectrometers is made and their advantages and shortcomings underlined. A critical analysis of the obtained results with the Li6-semiconductor spectrometer with plane geometry is given. A new type of Li6-semiconductor spectrometer is described, its characteristics experimentally determined, and a comparison of it with a classical Li6-spectrometer made (author)

100

Measurement of environmental radioactivity. Ispra 1977  

International Nuclear Information System (INIS)

In this report there are briefly described the measurements of environmental radioactivity performed during 1977 by the site survey group of the Protection Division of the Euratom joint Research Centre - Ispra Establishement. Data are given on the concentrations of 90Sr, 137Cs and other radionuclides in precipitation, air, waters, herbage, milk and radioactive effluents. The environmental contamination is mainly world-wide fall out

101

Measurement of environmental radioactivity. Ispra 1976  

International Nuclear Information System (INIS)

In this report there are briefly described the measurements of environmental radioactivity performed during 1976 by the site survey group of the Protection Division of the Euratom Joint Research Centre - Ispra Establisment. Data are given on the concentrations of 90Sr, 137Cs and other radionuclides in precipitation, air, waters, herbage milk and radioactive effluents. The environmental contamination is mainly world-wide fall out

102

Measured and modelled absolute gravity changes in Greenland  

DEFF Research Database (Denmark)

In glaciated areas, the Earth is responding to the ongoing changes of the ice sheets, a response knownas glacial isostatic adjustment (GIA). GIA can be investigated through observations of gravity change.For the ongoing assessment of the ice sheets mass balance, where satellite data are used, the study ofGIA is important since it acts as an error source. GIA consists of three signals as seen by a gravimeter onthe surface of the Earth. These signals are investigated in this study. The ICE-5G ice history and recentlydeveloped ice models of present day changes are used to model the gravity change in Greenland. Theresult is compared with the initial measurements of absolute gravity (AG) change at selected GreenlandNetwork (GNET) sites.We find that observations are highly influenced by the direct attraction from the ice and ocean. Thisis especially evident in the measurements conducted at the GNET station near the Helheim Glacier.The effect of the direct attraction diminishes at sites that are more than one degreefrom the source.Here, the dominant signal is the effect of the elastic signal from present day ice mass changes. We findagreement between the measured and modelled gravity changes at all but one site. This agreement onlyholds when the direct attraction is considered. For one site, there is no agreement, indicating that someimprovements to the modelling results or the processing of the gravity data are needed. In addition, moreAG measurements are needed to strengthen the time series of gravity change.

Nielsen, Jens Emil; Forsberg, René

2014-01-01

103

Absolute Thermal SST Measurements over the Deepwater Horizon Oil Spill  

Science.gov (United States)

Climate monitoring and natural disaster rapid assessment require baseline measurements that can be tracked over time to distinguish anthropogenic versus natural changes to the Earth system. Disasters like the Deepwater Horizon Oil Spill require constant monitoring to assess the potential environmental and economic impacts. Absolute calibration and validation of Earth-observing sensors is needed to allow for comparison of temporally separated data sets and provide accurate information to policy makers. The Ball Experimental Sea Surface Temperature (BESST) radiometer was designed and built by Ball Aerospace to provide a well calibrated measure of sea surface temperature (SST) from an unmanned aerial system (UAS). Currently, emissive skin SST observed by satellite infrared radiometers is validated by shipborne instruments that are expensive to deploy and can only take a few data samples along the ship track to overlap within a single satellite pixel. Implementation on a UAS will allow BESST to map the full footprint of a satellite pixel and perform averaging to remove any local variability due to the difference in footprint size of the instruments. It also enables the capability to study this sub-pixel variability to determine if smaller scale effects need to be accounted for in models to improve forecasting of ocean events. In addition to satellite sensor validation, BESST can distinguish meter scale variations in SST which could be used to remotely monitor and assess thermal pollution in rivers and coastal areas as well as study diurnal and seasonal changes to bodies of water that impact the ocean ecosystem. BESST was recently deployed on a conventional Twin Otter airplane for measurements over the Gulf of Mexico to access the thermal properties of the ocean surface being affected by the oil spill. Results of these measurements will be presented along with ancillary sensor data used to eliminate false signals including UV and Synthetic Aperture Radar (SAR) information. Spatial variations and day-to-day changes in the visible oil concentration on the surface of the water were observed in performing these measurements. An assessment of the thermal imagery variation will be made based on the absolute calibration of the sensor to determine if the visible variation was due to properties of the reflected light or of the actual oil composition. Comparisons with satellite data (both SAR and thermal infrared images) and buoy data will also be included.

Good, W. S.; Warden, R.; Kaptchen, P. F.; Finch, T.; Emery, W. J.

2010-12-01

104

[Absolute measurements of cross section neutrons]: Progress report  

International Nuclear Information System (INIS)

Over the past year, the cross section project at the University of Michigan has continued activities in two major areas. In the Neutron Experimental Bay, we have been employing a 150 kV Cockcroft-Walton accelerator as a 14 MeV neutron generator in the measurement of a number of activation cross sections. These have included the completion of a measurement of a number of activation cross sections. These have included the completion of a measurement of the Cr(n,X)52V cross section, and the near-completion of measurements of the 65Cu(n,2n)64Cu, 64Zn(n,p)64Cu, and 56Fe(n,p)56Mn cross sections. Over the past year, we have also taken steps to place these measurements on a more nearly absolute basis through the use of a proton recoil fast neutron monitor. In the photoneutron Laboratory, we have continued work on the measurement of the U-238 capture cross section at neutron energies between 23 and 964 keV. We have also begun work on planning for a major redirection of our 14 MeV program. We have made plans for the conversion of our present steady state neutron generator into a facility capable of generating 14 MeV neutron pulses of 1--2 nanosecond duration. Ion beam optics codes have been adapted to predict the performance of various components that are needed to carry out this conversion. 4 refs., 2 figs., 1 tab

105

Instruments for measuring water radioactivity  

International Nuclear Information System (INIS)

The requirements are discussed put on instruments for measuring the concentrations of radionuclides in water with regard to the type of radionuclides and the methods of sample preparation and sampling and of evaluation of the results. Methods are briefly described used for measuring the volume activity of waters and instruments developed and manufactured by TESLA, Czechoslovakia. The analysis of demands on the parameters of the instruments shows that samples with the lowest volume activity of 37 mBq/l cannot be directly measured by any instrument. The most favourable instruments for direct measurements are those with discontinuous measurement of gamma radiation; within several tens of minutes it is thus possible to determine the volume activity in the order of units and tens of Bq/l. Samples will have to be concentrated for measuring lower activities. (Z.M.)

106

Luminous-flux measurements by an absolute integrating sphere.  

Science.gov (United States)

We present an original implementation of the absolute-sphere method recently proposed by Ohno. The luminous-flux unit, the lumen, is realized by means of an integrating sphere with an opening calibrated by a luminous-intensity standard placed outside. The adapted experimental setup permits one to measure luminous-flux values between 5 and 2500 lm with a significant improvement with respect to the simulated performances reported in the literature. Traditionally, the luminous-flux unit, the lumen, is realized by goniophotometric techniques in which the luminous-intensity distribution is measured and integrated over the whole solid angle. Thus sphere results are compared with those obtained with the Istituto Elettrotecnico Nazionale goniophotometer. In particular, a set of standards, characterized by luminous-flux values of ~2000 lm, has been calibrated with both techniques. We highlight some of the problems encountered. Experimental results show that the agreement between the two methods is within the estimated uncertainty and suggest promising areas for future research. PMID:21102851

Rastello, M L; Miraldi, E; Pisoni, P

1996-08-01

107

Absolute measurement of the neutron emission rate with a manganese sulphate bath system  

International Nuclear Information System (INIS)

Recently, an absolute measurements of the neutron emission rates of neutron sources were carried out for 241Am - Be and 252Cf over a wide range of emission rates (2 x 105 ? 2 x 108 s-1). The measurements were done using a Manganese Sulphate Bath method, which is the principal method for the absolute determination of the neutron emission rates of radionuclide neutron sources. The efficiency of the system was determined by means of a 56Mn radioactive source of well-defined activity. Various corrections, including epithermal neutron capture, the (n, p) and the (n, ?) reactions, the leakage of neutrons, etc., were replaced by a direct calculation of the neutron capture probability for manganese nuclei. The neutron capture probability of the manganese nuclei was determined by using a careful MCNP (Monte Carlo N-Particle Transport Code System) calculation and was 0.102 ? 0.105 for the present status of the KRISS (Korea Research Institute of Standards and Science) Manganese Sulphate Bath system. The emission rates were determined with an uncertainty of < 0.8 % (k = 1).

108

Absolute measurement of the neutron emission rate with a manganese sulphate bath system  

Energy Technology Data Exchange (ETDEWEB)

Recently, an absolute measurements of the neutron emission rates of neutron sources were carried out for {sup 241}Am - Be and {sup 252}Cf over a wide range of emission rates (2 x 10{sup 5} {approx} 2 x 10{sup 8} s{sup -1}). The measurements were done using a Manganese Sulphate Bath method, which is the principal method for the absolute determination of the neutron emission rates of radionuclide neutron sources. The efficiency of the system was determined by means of a {sup 56}Mn radioactive source of well-defined activity. Various corrections, including epithermal neutron capture, the (n, p) and the (n, {alpha}) reactions, the leakage of neutrons, etc., were replaced by a direct calculation of the neutron capture probability for manganese nuclei. The neutron capture probability of the manganese nuclei was determined by using a careful MCNP (Monte Carlo N-Particle Transport Code System) calculation and was 0.102 {approx} 0.105 for the present status of the KRISS (Korea Research Institute of Standards and Science) Manganese Sulphate Bath system. The emission rates were determined with an uncertainty of < 0.8 % (k = 1).

Park, H.; Choi, K. O.; Lee, J. M.; Lee, K. B.; Hahn, M. S. [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Kralik, M. [Czech Metrology Institute, IIR, Prague (Czech Republic)

2005-10-15

109

Radioactivity monitoring network: Measurements 1987  

International Nuclear Information System (INIS)

Four papers are presented: radionuclide concentration measurement in aerosols, surface water and the wastes of the Vienna Central Clarification Plant respectively, and on tritium in Austrian lakes and rivers. (qui)

110

Measuring systems for environmental radioactivity monitoring  

International Nuclear Information System (INIS)

There currently are six measuring systems in the Federal Republic of Germany, for monitoring airborne radioactivity. The systems have been set up for various purposes, and are equipped with different measuring instruments. The Chernobyl reactor accident and the resulting situation have revealed that there is urgent demand for modernizing the existing equipment and for establishing a national registry of measured data. The article reports current activities towards this end. (orig.)

111

Study on measurement of radioactive contamination  

International Nuclear Information System (INIS)

The complexity in analysis of results measuring the level of radioactive contamination with ?- particles, relative to personnel working in the field of radiation safety because of different units of measurements (?/ s,. cpm ,?Sv/h,?/ (min cm2)). This paper show the particle study to standardize the units of measurement specified calibration process to determine the factor of conversion in a unit ?/(mincm2) that allows a normalized unit. (Author)

112

Radioactivity measurements on live Bewick's Swans  

International Nuclear Information System (INIS)

Measurements made on 46 live swans at Slimbridge using portable high resolution hyperpure germanium gamma ray spectrometry equipment are described. Laboratory measurements are also reported on two swans which died of natural causes or of flying accidents. The implications of the measured radioactivity levels are discussed in relation to the suggestion that they might have been affected by the Chernobyl accident on their migration. (UK)

113

Environmental radioactivity measurement intercomparison exercise 1990  

International Nuclear Information System (INIS)

In a recent national intercomparison exercise, 49 laboratories involved in making environmental radioactivity measurements took part in the analysis of samples supplied by the National Physical Laboratory (NPL) in the United Kingdom. There were two sets of samples; one containing pure ?-emitters and one containing ?/?-emitters. Two thirds of the participants measured the ?/?-emitter sample only, the remainder measured both. The results are presented. (author)

114

Accurate absolute measurement of trapped Cs atoms in a MOT  

International Nuclear Information System (INIS)

A Cs-133 Magneto-Optical Trap (MOT) has been developed at the Time and Frequency Division of the Centro Nacional de Metrologia, CENAM, in Mexico. This MOT is part of a primary frequency standard based on ultra-cold Cs atoms, called CsF-1 clock, under development at CENAM. In this Cs MOT, we use the standard configuration (?+ - ?-) 4-horizontal 2-vertical laser beams 1.9 cm in diameter, with 5 mW each. We use a 852 nm, 5 mW, DBR laser as a master laser which is stabilized by saturation spectroscopy. Emission linewidth of the master laser is l MHz. In order to amplify the light of the master laser, a 50 mW, 852 nm AlGaAs laser is used as slave laser. This slave laser is stabilized by light injection technique. A 12 MHz red shift of the light is performed by two double passes through two Acusto-Optic Modulators (AOMs). The optical part of the CENAMs MOT is very robust against mechanical vibration, acoustic noise and temperature changes in our laboratory, because none of our diode lasers use an extended cavity to reduce the linewidth. In this paper, we report results of our MOT characterization as a function of several operation parameters such as the intensity of laser beams, the laser beam diameter, the red shift of light, and the gradient of the magnetic field. We also report accurate absolute measurement of the number of Cs atoms trapped in our Cs MOT. We found up to 6 x 107 Cs atoms trapped in our MOT measured with an uncertainty no our MOT measured with an uncertainty no greater than 6.4%. (Author)

115

Nondestructive measurement of environmental radioactive strontium  

Directory of Open Access Journals (Sweden)

Full Text Available The Fukushima Daiichi nuclear power plant accident was triggered by the 2011 Great East Japan Earthquake. The main radioactivity concerns after the accident are I-131 (half-life: 8.0 days, Cs-134 (2.1 years, Cs-137 (30 years, Sr-89 (51 days, and Sr-90 (29 years. We are aiming to establish a new nondestructive measurement and detection technique that will enable us to realize a quantitative evaluation of strontium radioactivity without chemical separation processing. This technique is needed to detect radiation contained in foods, environmental water, and soil, to prevent us from undesired internal exposure to radiation.

Saiba Shuntaro

2014-03-01

116

Nondestructive measurement of environmental radioactive strontium  

OpenAIRE

The Fukushima Daiichi nuclear power plant accident was triggered by the 2011 Great East Japan Earthquake. The main radioactivity concerns after the accident are I-131 (half-life: 8.0 days), Cs-134 (2.1 years), Cs-137 (30 years), Sr-89 (51 days), and Sr-90 (29 years). We are aiming to establish a new nondestructive measurement and detection technique that will enable us to realize a quantitative evaluation of strontium radioactivity without chemical separation processing. This technique is nee...

Saiba Shuntaro; Okamiya Tomohiro; Tanaka Saki; Tanuma Ryosuke; Totsuka Yumi; Murata Jiro

2014-01-01

117

Nondestructive measurement of environmental radioactive strontium  

Science.gov (United States)

The Fukushima Daiichi nuclear power plant accident was triggered by the 2011 Great East Japan Earthquake. The main radioactivity concerns after the accident are I-131 (half-life: 8.0 days), Cs-134 (2.1 years), Cs-137 (30 years), Sr-89 (51 days), and Sr-90 (29 years). We are aiming to establish a new nondestructive measurement and detection technique that will enable us to realize a quantitative evaluation of strontium radioactivity without chemical separation processing. This technique is needed to detect radiation contained in foods, environmental water, and soil, to prevent us from undesired internal exposure to radiation.

Saiba, Shuntaro; Okamiya, Tomohiro; Tanaka, Saki; Tanuma, Ryosuke; Totsuka, Yumi; Murata, Jiro

2014-03-01

118

Molybdenum purification and very low radioactivity measurements  

International Nuclear Information System (INIS)

The success of the NEMO (Neutrino Experiment with Molybdenum) experiment is closely related to the realization of very pure thin 100Mo sources. To this purpose advanced chemical extraction methods associated to radioactivity tests with ultra low background Ge detector have been developed. The purification of molybdenum consists in the extraction of the elements K, Ra, Th, U from a Mo matrix. The method is based on the similar properties of Ra++ and Ba++ ions on one hand and on the different precipitation conditions of the Mo, Th and U oxides in nitric medium on the other hand. Two to three months are necessary to treat 1 kg of Mo. The radioactive measurements were carried out with a 400 cm3 Ge detector installed at Laboratoire Souterrain de Modane (LSM). The chemical extraction factors obtained for the elements Ra, Th, U and K are 40, 100, 100 and 80, respectively. The simulations realized with the GEANT code give for the acceptable radioactivity limit for the 100Mo source of NEMO the values: 0.33 mBq/kg of 214Bi and 0.017 mBq/kg of 208Tl. The measurements of such a low radioactivity impose a large volume low level Ge spectrometer shielded against the cosmic radiation.The Ge detector operating at LSM is used for radioactivity measurements of molybdenum as well as to check the performances of chemical extraction. Besides the severe conditions imposed by the required sensitivities, in the measurements one has to take into account the radon present in the laboratory and, consequently, in the container holding the sample to be measured. The variation of the counting rate shows a steep decay (the half-life of 222Rn is 3.8 d) followed by a plateau of 0.59 ±0.03 c/h

119

Radioactivity measurements as tool for physics dissemination  

International Nuclear Information System (INIS)

In general people associate environmental radioactivity with the artificial radioactivity and knows very little about natural radioactivity. Thus there is a critical need to improve nuclear physics public education. From 2005 in Italy two programs were promoted from Ministry of Education and University and National Institute of Nuclear Physics (INFN) for scientific dissemination in the field of environmental radioactivity. High school students in many Italian regions were involved in particular in indoor radon measurements. With this program students acquired awareness about the risks of inhalation of radon and its progeny and at the same time contributed to carry out radon monitoring, participating to all the experimental phases, from detectors set-up to data analysis. In particular we report about the activities carried out at Catania University and INFN division regarding a survey in the eastern Sicily. The overall monitoring, spanned over a period of 5 years, was carried out using passive nuclear track detection technique, through CR-39 dosimeters. In total about 500 detectors were placed in dwellings and schools in 57 locations. The investigated area have shown medium-high indoor radon concentrations, higher than the Italian average (70 Bq/m3). From the evaluation of the participating teachers and students, this kind of activities represents a successful strategy to enhance dissemination of physics, in particular in radioactivity topics. (author)

120

Residual radioactivity measurements at Indus accelerator complex  

International Nuclear Information System (INIS)

Indus-1 and Indus-2 are two Synchrotron Radiation Sources (SRS) operational at RRCAT, Indore. Indus-1 and Indus-2 are designed for maximum electron beam energy of 450 MeV and 2.5 GeV respectively. During shut down of these accelerators for maintenance purpose, residual radioactivity measurements were carried out. The residual radioactivity formation in various parts of the high energy electron accelerators is due to the beam loss taking place at these locations. The present paper describes the recent residual radioactivity measurements carried out at the electron accelerators of Indus Accelerator Complex and the radio-isotopes identified. The maximum dose rate due to induced activity obtained is 30 ?Sv/h, near dipole-5 of booster synchrotron after 12 h of cooling time. In case of Indus-1 and Indus-2 SRS the dose rate due to induced radioactivity is found to be of the order of 2 - 3 ?Sv/h. The radio isotopes identified at these beam loss locations are beta emitters that do not pose serious external hazard to the working personnel. However, precautions are to be observed while doing maintenance on activated components. The paper describes the measurements in detail with the results. (author)

121

Uncertainty vade-mecum in radioactivity measurement  

International Nuclear Information System (INIS)

This article reviews the tools available to assign realistic uncertainties in the field of radioactivity measurements following the prescriptions of the Guide to the Expression of Uncertainty in Measurement. A presentation of different distributions that can be encountered in the analysis of radioactivity measurements is listed, and explained using simple but pertinent examples. Two different methods, a simplified coincidence method and ? counting, are considered, for each of which a detailed uncertainty budget is given. This leads into the characteristics function and the law of propagation of errors that can be used in the evaluation of the total uncertainty. The treatment of correlations, which occur when using the same set of sources and the same decay period for both methods, is also detailed. Subsequently, the analysis of the results of a comparison of activity measurements made by various national laboratories is presented with special care regarding the treatment of correlations that may arise. (author)

122

Environmental radioactivity - problems in activity measurements  

International Nuclear Information System (INIS)

Laboratory methods for the measurement of radioactivity in environmental samples are considered to be well developed and established. After the Chernobyl accident, however, it became evident that not everywhere was one prepared for quick in-situ activity measurements and that many measurement results were questionable. We show the difficulties occurring in activity measurements with simple instruments to be used directly in the environment. In addition, several problems in gamma-ray spectrometry with environmental samples are discussed, problems which - if disregarded - may also lead to erroneous activity values in the case of laboratory measurements. (orig./HP)

123

Method of improve detection efficiency for liquid scintillation absolute measurement  

International Nuclear Information System (INIS)

Introduce practical method to improve the detection efficiency of 3H, 14C sample, as used for metrology technique research, graduation solution of 3H, 14C by National Primary Standard of 4??(LS) radioactivity. (authors)

124

Radioactivity measurements in potassium enriched vegetation  

International Nuclear Information System (INIS)

Measurements of radioactivity in food stuffs/vegetation is important because radiation dose to human population due to inhalation and ingestion (external and internal exposure) poses health hazard and contribute significantly to the total dose from natural sources. The radium and thorium isotopes always present in the body are measured in units of a millionth or a billionth of a gram, but when it comes to potassium we are talking about grams of material. The 2.5 g of potassium ingested each day contains 80 Becquerel (Bq) (or 2100 pCi) of 40K that quantity which produces 80 radioactive decays each second. The 140 g of potassium in a normal male contains about 4400 Bq (or 120,000 pCi) of 40K; that quantity produces a decay rate of about 4400 disintegrations per second. That means that 4400 radioactive 40K atoms decay and emit radiation in our bodies each second for as long as we live. Since potassium is found in the intracellular fluids, about 98 % of the potassium in the body is within cells. Thus at least 98 % of these disintegrations take place within body cells, and are potentially capable of altering the cell's DNA. Therefore, it is very essential to measure the activity concentration in the potassium enriched food stuffs. Knowledge of radioactivity present in potassium enriched food stuffs enables one to assess any possible radiological hazard to mankind by the use of such materials. In the light of the above mentioned facts, it is, therefore, fundamental to assess the radioactivity in commonly available potassium enriched foods. (author)

125

Measurement and analysis of radioactive substances  

International Nuclear Information System (INIS)

Here are gathered the abstracts presented to the 3. summer university of the year 2001 whose main themes were the destructive (5 conferences) and nondestructive (8 conferences) analyses applied to nuclear industry. The points of view of different organisms (as DSIN: Directorate for the Safety of Nuclear Installations, IPSN: Institute of Nuclear Protection and Safety, OPRI: Office of Protection against Ionizing Radiations, TUI: Institute for Transuranium Elements, COGEMA, EDF: Electric Utilities, ANDRA: French National Agency for Radioactive Waste Management, CRLC Val d'Aurelle, France) concerning the needs involved in nuclear facilities control, the methods of radionuclide speciation in use internationally, the measurements and analyses of radioactive substances are given too as well as some general concepts concerning 1)the laser-matter interaction 2)the ions production 3)the quality applied to the measurements and analyses 4)the standard in activity metrology. (O.M.)

126

Single detector-based absolute velocity measurement using spectral domain Doppler optical coherence tomography  

Science.gov (United States)

We propose an approach for absolute velocity measurement where the use of a beam displacer provides two orthogonal linearly polarized beams to probe the sample simultaneously at two different incidence angles. The approach helps remove the cross talk image and facilitates single detector-based Fourier domain Doppler velocity measurement. The system has been characterized by quantifying absolute flow velocity in a flow phantom.

Kumar, S.; Verma, Y.; Sharma, P.; Shrimali, R.; Gupta, P. K.

2014-10-01

127

Absolute activity measurement of 198Au and 116In neutron activation detectors  

International Nuclear Information System (INIS)

The absolute measurement of activity of Au- and In-activation detectors by the 4?? proportional flow counter with methane filling has been presented. All correction factors, necessary for absolute measurements have been quoted. The particularly attention is paid to self-absorption coefficient, since it is significant, and amounts from 0.4 to 0.98. (author)

128

Radioactivity. Nuclear radiation and measured variables; Radioaktivitaet. Strahlenarten und Messgroessen  

Energy Technology Data Exchange (ETDEWEB)

The brochure on radioactivity covers the following issues: radioactivity and ionizing radiation (alpha, beta and gamma radiation), measuring unit for activity: Becquerel, measuring unit for radiation dosis: Sievert, radiation sources and radiation effects, radiation exposure by various radiation sources.

NONE

2014-02-15

129

Methods applied for measuring radioactive environmental isotopes  

International Nuclear Information System (INIS)

Hydrologic applications of the radioactive environmental isotopes 3H, 14C and 85Kr require measuring methods, whose detection limits range 1 to 2 magnitudes below the concentrations of these radionuclides in recently generated groundwater. The study gives a survey about the corresponding analytic methods, which are applicable today at the GSF Institute for Radiohydrometry. In addition some information about the detection of 39Ar is provided. (orig.)

130

Error calculations statistics in radioactive measurements  

International Nuclear Information System (INIS)

Basic approach and procedures frequently used in the practice of radioactive measurements.Statistical principles applied are part of Good radiopharmaceutical Practices and quality assurance.Concept of error, classification as systematic and random errors.Statistic fundamentals,probability theories, populations distributions, Bernoulli, Poisson,Gauss, t-test distribution,?2 test, error propagation based on analysis of variance.Bibliography.z table,t-test table, Poisson index ,?2 test

131

Absolute measurement of 238U capture rate on FCA Assembly V-2  

International Nuclear Information System (INIS)

An absolute measurement of 238U capture rate was made on FCA Assembly V-2, a physics mock-up of JOYO. The method is that 239Np activities were counted with a Ge(Li) detector which had been absolutely calibrated by using 238U foils irradiated in the standard thermal neutron facility. The absolute fission rate was also measured with an absolute fission counter of enriched uranium and we obtained 0.141 +-3% for 28?sub(c)/25?sub(f) at the core center. This value is larger than the calculated ones with the JAERI-FAST Version II, RCBN and ABBN set. (author)

132

Comparison of available measurements of the absolute fluorescence yield  

OpenAIRE

Abstract The uncertainty in the absolute value of the fluorescence yield is still one of the main contributions to the total error in the reconstruction of the primary energy of ultra-energetic air showers using the fluorescence technique. A significant number of experimental values of the fluorescence yield have been published in the last years, however reported results are given very often in different units (photons/MeV or photons/m) and for different wavelength intervals. In th...

Rosado, J.; Blanco, F.; Arqueros, F.

2010-01-01

133

Accurate absolute measurement of trapped Cs atoms in a MOT  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish Una Trampa Magneto-Óptica (MOT) de Cs-133 se ha desarrollado en la División de Tiempo y Frecuencia del Centro Nacional de Metrología, CENAM, en Mexico. Esta MOT es parte de un patrón primario de frecuencia basado en átomos ultra fríos de Cs, llamado reloj CsF-1 que se encuentra en desarrollo en el C [...] ENAM. En esta MOT de Cs, se emplea la configuracion estándar (?+ - ?-) de 4 haces laser horizontales y 2 verticales de 1.9 cm de diametro con 5 mW de potencia cada uno. Se utiliza un láser DBR de 852 nm y 5 mW como láser maestro estabilizado por espectroscopia de saturación. El ancho de línea de emision del láser maestro es de 1 MHz. Para amplificar la luz del láser maestro, se emplea un laser esclavo de AlGaAs de 852 nm y 50 mW de potencia. Este láser esclavo es estabilizado por la técnica de inyección de luz. Se realiza un corrimiento de la luz al rojo de 12 MHz por un doble paso a través de dos Moduladores Acusto-Ópticos (AOMs). La parte óptica de la MOT del CENAM es muy robusta contra la vibracion mecánica, el ruido acústico y los cambios de temperatura en el laboratorio, debido a que ninguno de los diodos laser emplea una cavidad extendida para reducir el ancho de línea. En este trabajo se reportan los resultados de la caracterizacion de la MOT como una función de varios parámetros de operación tales como: intensidad y diámetro de los haces láser, corrimiento al rojo de la luz y el gradiente de campo magnético. También se reportan mediciones absolutas del número de átomos de Cs atrapados en la MOT. Se encontraron mas de 6 x 10(7) atomos de Cs atrapados, medidos con una incertidumbre que en ningún caso es mayor a 6.4%. Abstract in english A Cs-133 Magneto-Optical Trap (MOT) has been developed at the Time and Frequency Division of the Centro Nacional de Metrología, CENAM, in Mexico. This MOT is part of a primary frequency standard based on ultra-cold Cs atoms, called CsF-1 clock, under development at CENAM. In this Cs MOT, we use the [...] standard configuration (?+ - ?-) 4-horizontal 2-vertical laser beams 1.9 cm in diameter, with 5 mW each. We use a 852 nm, 5 mW, DBR laser as a master laser which is stabilized by saturation spectroscopy. Emission linewidth of the master laser is 1 MHz. In order to amplify the light of the master laser, a 50 mW, 852 nm AlGaAs laser is used as slave laser. This slave laser is stabilized by light injection technique. A 12 MHz red shift of the light is performed by two double passes through two Acusto-Optic Modulators (AOMs). The optical part of the CENAMs MOT is very robust against mechanical vibration, acoustic noise and temperature changes in our laboratory, because none of our diode lasers use an extended cavity to reduce the linewidth. In this paper, we report results of our MOT characterization as a function of several operation parameters such as the intensity of laser beams, the laser beam diameter, the red shift of light, and the gradient of the magnetic field. We also report accurate absolute measurement of the number of Cs atoms trapped in our Cs MOT. We found up to 6 x 10(7) Cs atoms trapped in our MOT measured with an uncertainty no greater than 6.4%.

M., Talavera O.; M., López R.; E., de Carlos L.; S., Jiménez S.

2007-10-01

134

Absolute continuity of autophage measures on finite-dimensional vector spaces  

International Nuclear Information System (INIS)

We consider a class of measures called autophage which was introduced and studied by Szekely for measures on the real line. We show that the autophage measures on finite-dimensional vector spaces over real or Qp are infinitely divisible without idempotent factors and are absolutely continuous with bounded continuous density. We also show that certain semistable measures on such vector spaces are absolutely continuous. (author)

135

Monitoring surface radioactive contamination by measuring instruments  

International Nuclear Information System (INIS)

The description and specification are given of devices with proper detecting units meant for monitoring of surfaces covered by protective accumulating or protective insulating coatings and for fixing the accumulated radioactive ?- and ?-contamination. The measurement of the pulse counting rates is performed in the 0.3-10000 imp/s range. The check of the instrument calibration is performed before each of the measure=ment series by means of super position on the sensitive part of the model source transducer, the external emission yield of which must be not less than 50 % of scale of the range under control. The method of measuring the complex surfaces, having considerable ?, ? contamination levels is described

136

Fallout radioactivities around Fukushima measured by gamma ray spectroscopy  

International Nuclear Information System (INIS)

After the accident of Fukushima Nuclear Power Plant, the fallout radioactivity map in soils around Fukushima measured by gamma ray spectroscopy has been prepared. The examination of radioactive materials absorbed by Fukushima's people (screening) has been made. (M.H.)

137

Absolute measurement of the neutronic activity of a 252Cf source  

International Nuclear Information System (INIS)

The absolute neutronic activity of a 252Cf source has been measured using a set of eight BF3 counters; each fission was identified, the corresponding detected neutrons were counted for a time equal to the maximum lifetime of these neutrons in the moderator, the number of prompt neutrons was determined and the probability of detection for one neutron in the BF3 counter was measured. After corrections have been completed, the absolute accuracy of measurement is estimated to be 1%

138

Radioactivity measurements for air-dust samples around Fukushima prefecture  

International Nuclear Information System (INIS)

A large amount of radioactive materials were released in the environment by the accident at the Fukushima Daiichi Nuclear Power Station. To investigate pollution status and behavior of radioactive materials in the environment, it is essential to monitor amounts of these radioactive materials in the environment at several places for long term. We have been collecting air-dust using high volume air sampler at Fukushima city (Fukushima Pref.), Marumori town (Miyagi Pref.) and Hitachi city (Ibaraki Pref.) since the accident. We identified the radioactivities of 134Cs and 137Cs in filters using HPGe detector. The activity ratio of 134Cs/137Cs was mostly constant, on the other hand, the absolute activity of 134Cs and 137Cs varied with sample collection date by about ten times. In this report, we discuss the relationship between the time variation of the radioactivity concentrations and meteorological phenomenon. (author)

139

Quality control of environmental radioactivity measurements  

International Nuclear Information System (INIS)

Quality control of measured data from an environmental monitoring network is of great importance to assure that further dose assessments and measures are based on reliable data. The demand for a fast data flow requires a clear concept and predefined criteria. Even if data have passed technical check procedures, according to daily experience, some of them will still be inconsistent with others in a radioecological sense. A model of interdependencies for six well established fast detection methods for radioactivity in the air and on the ground is presented and the checks for consistency are discussed. In a further step it is shown how data from stations with an incomplete set of instrumentation can be interpreted on the basis of the model results. An expert system written in PROLOG and presently running as a demo version has been developed on the basis of this model in cooperation with DORNIER. (author)

140

Why the Bradley aberration cannot be used to measure absolute speeds. A comment  

CERN Document Server

In a recent article in this journal [G. Sardin, Measure of the absolute speed through the Bradley aberration of light beams on a three-axis frame, Europhys. Lett. 53 (2001) 310], Sardin proposed to use the Bradley aberration of light for the construction of a speedometer capable of measuring absolute speeds. The purpose of this comment is to show that the device would not work.

Kassner, K

2002-01-01

141

Absolute dose measurement Gafchromic R EBT2 movies. Case Study of Kaposis sarcoma  

International Nuclear Information System (INIS)

Because of its high spatial resolution, low energy dependence and good response over a wide energy range, EBT2 Gafchromic films are widely used in many applications in radiotherapy for measuring relative dose. Despite being the most common use can be used to measure absolute dose. This text is an example of using films as EBT2 for in vivo absolute dose in a Kaposis sarcoma.

142

Ethernet-based automation in radioactivity measurements  

International Nuclear Information System (INIS)

The paper describes an integrated radioactivity measurements laboratory involved in a New York State program of monitoring environmental radioactivity and bioassay samples. The laboratory is set up as a comprehensive Ethernet network that integrates radiation detectors, electronics hardware components as well as software automation and communications. Two DEC VAXstations 3100 and 3200 are central to the system. The VAXstation 3100 runs the Canberra/Nuclear Data Genie data-acquisition program. The Acquisition Interface Modules interface the ADCs to the Ethernet. Using the DEC Pathworks, the VAXstation 3100 is also a server for the Ethernet-based network of several 486 and 386 PCs. A designated PC can display the Genie acquisition window, in addition to the main window at VAXstation 3100. Another PC collects data from several NaI detectors using the Oxford/Nucleus DMR-II program. The paper also describe the plans for the future upgrades such as installation of VAXstation 4000/90 as well as interfacing the proportional counters and surface barrier detectors to the network

143

Measurement of Radioactivity in the Human Body  

Energy Technology Data Exchange (ETDEWEB)

A body counter with a steel room and a 4-inch-diameter by 4-inch thick Nal scintillation counter has been in operation since February 1958. It is used to control the internal contamination in people working with radioactive materials. Measurements have also been made on the natural activity in the human body. The average cesium-137/potassium ratio in a group of Swedish males was in May 1959 73 {mu}{mu}c per gram of body potassium and in June 1960 55 {mu}{mu}c per gram of body potassium. The cessation of the nuclear bomb tests has caused a decrease in the cesium level in people. This gives some information of how cesium is entering the biosphere.

Andersson, I.Oe.; Nilsson, I.

1960-12-15

144

Absolute measurement of ? emitters with a 4 ? counter  

International Nuclear Information System (INIS)

The object of this work is to investigate the conditions under which the activity of ?-emitting radionuclides may be measured with a maximum of precision, and as a result to study the relevant corrections. The various problems relating to activity measurements with a 4 ? counter have been examined successively: - comparison of 4 ?, GM and proportional counters; - study of the preparation of sources; - corrections on the counting of sources; - self-absorption; - correction for absorption. The precision obtained on these measurements varies from 1.2 to 3 per cent, with the result that the 4 ? counter can be considered a very satisfactory calibration instrument. (author)

145

Absolute measurements of neutron cross sections. Progress report  

International Nuclear Information System (INIS)

In the photoneutron laboratory, we have completed a major refurbishing of experimental facilities and begun work on measurements of the capture cross section in thorium and U-238. In the 14 MeV neutron experimental bay, work continues on the measurement of 14 MeV neutron induced reactions of interest as standards or because of their technological importance. First results have been obtained over the past year, and we are extending these measurements along the lines outlined in our proposal of a year ago

146

Radioactivity measurements applied to glaciers and lake sediments  

International Nuclear Information System (INIS)

The behaviour of glaciers, polar ice-caps and lakes can be studied by means of natural and artificial radioactivity measurements conducted on snow (Alps, Arctic and Antarctic) and sediments samples. The nuclear decay of elements (210Pb and 238U filiation products) and nuclear events (atmospheric thermonuclear tests: 1954 and 1962-63; Chernobyl accident: 1986) allow an absolute dating of corresponding layers. These determinations need radiochemical separations (electro-plating, ion exchange filters), followed by ultra low level alpha and gamma spectrometries, or beta counting (137Cs, 90Sr). The high purity - N type - germanium detector (Compton-suppressed) allows the 210Pb analysis at 46.52 keV, enabling a direct comparison with 210Po alpha spectrometry. Typical applications concern primarily dating, and the determination of mean annual accumulation rates of glaciers, sedimentation rate and mixing time in lakes, with their associated spatio-temporal variations. These measurements give access to the global fallouts of radionuclides and to meteorological parameters: air to snow (or sediment) transfer, deposition processes and atmospheric circulation

147

Bolus injections of measured amounts of radioactivity  

Energy Technology Data Exchange (ETDEWEB)

Many time-based radionuclide techniques, such as glomerular filtration rate measurement (GFR), require prompt intravenous delivery of and accurately measured tracer bolus with minimal residual tracer retention at the injection site. The quality assurance aspects of two antecubital vein, quantitative injection techniques were investigated. A flush bolus technique using a tuberculin syringe piggybacked onto a 10-ml saline flush was compared to a single blood pressure cuff injection technique. Scintillation camera data for each technique were compared for bolus duration in the abdominal aorta and for residual activity at the injection site at 5 min. Bolus times were measured as the FWHM of the gamma variate fit to the abdominal aortic regional time-activity curves. Relatively little focal activity was seen in the antecubital injection site following the flush bolus: marked residual activity was seen following the blood pressure cuff injections. The injection site/arm background ratios averaged 1.3 for the flush bolus and 30.1 for the cuff technique. Although both methods allowed accurate in vitro determination of administered radioactivity, only the tuberculin syringe flush bolus technique was acceptable for time-based quantitation because of its superior in vivo characteristics.

Wesolowski, C.A.; Hogendoorn, P.; Vandierendonck, R.; Driedger, A.A.

1988-03-01

148

Bolus injections of measured amounts of radioactivity  

International Nuclear Information System (INIS)

Many time-based radionuclide techniques, such as glomerular filtration rate measurement (GFR), require prompt intravenous delivery of and accurately measured tracer bolus with minimal residual tracer retention at the injection site. The quality assurance aspects of two antecubital vein, quantitative injection techniques were investigated. A flush bolus technique using a tuberculin syringe piggybacked onto a 10-ml saline flush was compared to a single blood pressure cuff injection technique. Scintillation camera data for each technique were compared for bolus duration in the abdominal aorta and for residual activity at the injection site at 5 min. Bolus times were measured as the FWHM of the gamma variate fit to the abdominal aortic regional time-activity curves. Relatively little focal activity was seen in the antecubital injection site following the flush bolus: marked residual activity was seen following the blood pressure cuff injections. The injection site/arm background ratios averaged 1.3 for the flush bolus and 30.1 for the cuff technique. Although both methods allowed accurate in vitro determination of administered radioactivity, only the tuberculin syringe flush bolus technique was acceptable for time-based quantitation because of its superior in vivo characteristics

149

Absolute measurement of the activity of 222Rn using a proportional counter  

International Nuclear Information System (INIS)

A measuring set-up comprising a proportional counter of calculable 222Rn efficiency and quantifiable active volume (?V222Rn efficiency is determined by computer simulation of the measured ?-spectra. The procedures necessary for absolute measurements by means of the counter are described, and the suitability of the counter for absolute measurements of the 222Rn activity is proved by experiments. Thus, a new method for the realization of the unit of activity of 222Rn is obtained, which is independent of the unit of activity of 226Ra

150

Absolute measurement of laminar flow by an orthogonal excitation method in NMR tomography  

International Nuclear Information System (INIS)

A method for absolute measurement of flow quantities by excitation of a slice orthogonal to the measuring plane is presented. The developing flow profile can be imaged directly and its dynamic behaviour can be sampled and measured using the multiecho technique. Simple formulas can be derived by means of Hagen-Poiseuille's law for quantification. (orig.)

151

Thorough subcells diagnosis in a multi-junction solar cell via absolute electroluminescence-efficiency measurements.  

Science.gov (United States)

World-wide studies on multi-junction (tandem) solar cells have led to record-breaking improvements in conversion efficiencies year after year. To obtain detailed and proper feedback for solar-cell design and fabrication, it is necessary to establish standard methods for diagnosing subcells in fabricated tandem devices. Here, we propose a potential standard method to quantify the detailed subcell properties of multi-junction solar cells based on absolute measurements of electroluminescence (EL) external quantum efficiency in addition to the conventional solar-cell external-quantum-efficiency measurements. We demonstrate that the absolute-EL-quantum-efficiency measurements provide I-V relations of individual subcells without the need for referencing measured I-V data, which is in stark contrast to previous works. Moreover, our measurements quantify the absolute rates of junction loss, non-radiative loss, radiative loss, and luminescence coupling in the subcells, which constitute the "balance sheets" of tandem solar cells. PMID:25592484

Chen, Shaoqiang; Zhu, Lin; Yoshita, Masahiro; Mochizuki, Toshimitsu; Kim, Changsu; Akiyama, Hidefumi; Imaizumi, Mitsuru; Kanemitsu, Yoshihiko

2015-01-01

152

Thorough subcells diagnosis in a multi-junction solar cell via absolute electroluminescence-efficiency measurements  

Science.gov (United States)

World-wide studies on multi-junction (tandem) solar cells have led to record-breaking improvements in conversion efficiencies year after year. To obtain detailed and proper feedback for solar-cell design and fabrication, it is necessary to establish standard methods for diagnosing subcells in fabricated tandem devices. Here, we propose a potential standard method to quantify the detailed subcell properties of multi-junction solar cells based on absolute measurements of electroluminescence (EL) external quantum efficiency in addition to the conventional solar-cell external-quantum-efficiency measurements. We demonstrate that the absolute-EL-quantum-efficiency measurements provide I–V relations of individual subcells without the need for referencing measured I–V data, which is in stark contrast to previous works. Moreover, our measurements quantify the absolute rates of junction loss, non-radiative loss, radiative loss, and luminescence coupling in the subcells, which constitute the “balance sheets” of tandem solar cells. PMID:25592484

Chen, Shaoqiang; Zhu, Lin; Yoshita, Masahiro; Mochizuki, Toshimitsu; Kim, Changsu; Akiyama, Hidefumi; Imaizumi, Mitsuru; Kanemitsu, Yoshihiko

2015-01-01

153

Radioactivity measurements using storage phosphor technology  

Energy Technology Data Exchange (ETDEWEB)

We propose to apply a recently developed charged particle radiation imaging concept in bio-medical research for fast, cost-effective characterization of radionuclides in contaminated sites and environmental samples. This concept utilizes sensors with storage photostimulable phosphor (SPP) technology as radiation detectors. They exhibit high sensitivity for all types of radiation and the response is linear over a wide dynamic range (>10{sup 5}), essential for quantitative analysis. These new sensors have an Active area of up to 35 cm x 43 cm in size and a spatial resolution as fine as 50 {mu}m. They offer considerable promise as large area detectors for fast characterization of radionuclides with an added ability to locate and identify hot spots. Tests with SPP sensors have found that a single alpha particle effect can be observed and an alpha field of 100 dpm/100 cm{sup 2} or a beta activity of 0.1 dpm/mm{sup 2} or gamma radiation of few {mu}R/hr can all be measured in minutes. Radioactive isotopes can further be identified by energy discrimination which is accomplished by placing different thicknesses of filter material in front of the sensor plate. For areas with possible neutron contamination, the sensors can be coupled to a neutron to charged particle converter screen, such as dysprosium foil to detect neutrons. Our study has shown that this approach can detect a neutron flux of 1 n/cm{sup 2}s or lower, again with only minutes of exposure time. The utilization of these new sensors can significantly reduce the time and cost required for many site characterization and environmental monitoring tasks. The {open_quotes}exposure{close_quotes} time for mapping radioactivity in an environmental sample may be in terms of minutes and offer a positional resolution not obtainable with presently used counting equipment. The resultant digital image will lend itself to ready analysis.

Cheng, Y.T. [NeuTek, Darnestown, MD (United States); Hwang, J. [Advanced Technologies and Labs. International, Rockville, MD (United States); Hutchinson, M.R. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

1995-10-01

154

Development of a MEMS gyroscope for absolute angle measurement  

Science.gov (United States)

MEMS gyroscopes are typically designed to measure angular rate of rotation. A measurement of the angle itself is useful in many applications but cannot be obtained by integrating the angular rate due to the presence of bias errors which cause a drift. This thesis presents an innovative design for a vibrating gyroscope that can directly measure both angle and angular rate. The design is based on the principle of measuring the angle of free vibration of a suspended mass with respect to the casing of the device. Several critical challenges have to be handled before the theoretical sensing concept can be converted into a reliable practical sensor. These include compensating for the presence of dissipative forces, mismatched springs, cross-axis stiffness and transmission of rotary torque. These challenges are addressed by the development of a composite nonlinear feedback control system that compensates for each of the above effects and ensures that the mass continues to behave as a freely vibrating structure. Theoretical analysis and simulation results presented in this thesis show that the gyroscope can accurately measure both angle and angular rate for low bandwidth applications. A MEMS device is designed and fabricated to evaluate the real-world experimental performance of the sensor. It utilizes electrostatic comb actuators and capacitive sensing along both vibration axes fabricated by using Deep Reactive Ion Etching (DRIE) technique. Sensor noise is found to be a major impediment to successful implementation of the controller. The use of a Kalman filter enables some mitigation of noise and successful implementation of control, but the Kalman filter gain cannot be selected too high due to system stability limitations. In summary, the developed sensor provides a slightly improved measurement of angle compared to that obtained from integrating a commercially available rate gyroscope. However, due to noisy position measurements, it is unable to provide the drift free performance predicted by theory. Several lines of investigation are suggested in the thesis to study and solve the noise problem associated with the capacitive sensors. Simulations show that reducing the noise in the capacitive sensors will enable significantly superior angle measurement.

Piyabongkarn, Damrongrit

155

Measurements of the Absolute Flux of Atmospheric Muons with BESS  

Science.gov (United States)

We measured atmospheric muon fluxes during ascending (800 4 g/cm2 ) and floating (ab out 5 g/cm2 ) periods of the BESS balloon flight experiments. The observations were carried out at Lynn Lake, Manitoba, Canada in 1999 and 2000 and at Ft. Sumner, New Mexico, USA in 2001. The atmospheric depth dependence on the muon fluxes was clearly observed.

Yamamoto, Y.; Abe, K.; Sanuki, T.; Anraku, K.; Fuke, H.; Haino, S.; Imori, M.; Izumi, K.; Maeno, T.; Makida, Y.; Matsuda, S.; Matsui, N.; Matsumoto, H.; Mitchell, J.; Moiseev, A.; Nishimura, J.; Nozaki, M.; Orito, S.; Ormes, J. F.; Sasaki, M.; Seo, E. S.; Shikaze, Y.; Streitmatter, R. E.; Suzuki, J.; Tanaka, K.; Tanizaki, K.; Yamagami, T.; Yamamoto, A.; Yamato, K.; Yoshida, T.; Yoshimura, K.

2003-07-01

156

Absolute measurements of neutron cross sections. Progress report  

International Nuclear Information System (INIS)

The measurement of the Cr(n,x)52V cross section at 14.6 MeV is discussed. Included in the discussion are sample preparation, counting systems, and calibration techniques. Future projects are also discussed. 13 refs., 2 figs., 3 tabs

157

Perfusion measurements with radioactively labelled microspheres  

International Nuclear Information System (INIS)

The technique and the evaluation of the microsphere-method are comprehensively represented in theory and practice. Some changes and new concepts are discussed, besides the known foundations and techniques, that assure an essential methodic improvement resp. practical simplifications. Two new formulas are derived within the frame of the theoretical principles, by which the absolute flux of shorts can be calculated, i.e. on the one hand in the case of known and on the other hand in the case of unknown applied amount of indicator. The determination of the optimal indicator dose is defined and formulated mathematically with respect to the experimental conditions to be expected. The matrix method was designed for the analysis of complex gamma spectra. Hereby there is no selective error accumulation in the case of low energy radio nuclids contrary to the so far exclusively used stripping technique. The number of possible error quantities was reduced by one resp. two variables. The error of particular radio nuclid components is quantitatively computed as standard deviation by means of the theory of approximated systems of linear equations. The external measurement of distance was developed. This technique is less susceptible for errors as the aliquota i.e. whole body measurement technique. Additionally less measurement time is needed. A flexible computer program for a desk top computer was developped for the evaluation. The data from the gamma spectrometer are recorded on tipe and automatically read in by the computer. The manual input are limited to the weights of the organs and some control parameter. The output is made by a clearly arranged table by means of a lineprinter. (orig./MG)

158

Radioactivity  

International Nuclear Information System (INIS)

This pedagogical document presents the origin, effects and uses of radioactivity: where does radioactivity comes from, effects on the body, measurement, protection against radiations, uses in the medical field, in the electric power industry, in the food (ionization, radio-mutagenesis, irradiations) and other industries (radiography, gauges, detectors, irradiations, tracers), and in research activities (dating, preservation of cultural objects). The document ends with some examples of irradiation levels (examples of natural radioactivity, distribution of the various sources of exposure in France). (J.S.)

159

Absolute fast neutral beam flux measurements using a pyroelectric detector  

International Nuclear Information System (INIS)

An inexpensive, sensitive pyroelectric bolometer for use as a fast neutral beam detector is described. Experimentally determined responsivity and noise equivalent power are presented, and are shown to agree with theoretical predictions. The detector has been used to measure the power absorption coefficient and the secondary electron ejection coefficients for 150 eV to 10 keV hydrogen and helium atoms impinging on a silver surface. (author)

160

Absolute Oxygenation Metabolism Measurements Using Magnetic Resonance Imaging  

OpenAIRE

Cerebral oxygen metabolism plays a critical role in maintaining normal function of the brain. It is the primary energy source to sustain neuronal functions. Abnormalities in oxygen metabolism occur in various neuro-pathologic conditions such as ischemic stroke, cerebral trauma, cancer, Alzheimer’s disease and shock. Therefore, the ability to quantitatively measure tissue oxygenation and oxygen metabolism is essential to the understanding of pathophysiology and treatment of various diseases....

An, Hongyu; Liu, Qingwei; Eldeniz, Cihat; Lin, Weili

2011-01-01

161

Absolute electron density measurements in the equatorial ionosphere  

International Nuclear Information System (INIS)

Accurate measurement of the electron density profile and its variations is crucial to further progress in understanding the physics of the disturbed equatorial ionosphere. To accomplish this, a plasma frequency probe was included in the payload complement of two rockets flown during the CONDOR rocket campaign conducted from Peru in March 1983. In this paper we present density profiles of the disturbed equatorial ionosphere from a night-time flight in which spread-F conditions were present and from a day-time flight during strong electrojet conditions. Results from both flights are in excellent agreement with simultaneous radar data in that the regions of highly disturbed plasma coincide with the radar signatures. The spread-F rocket penetrated a topside depletion during both the upleg and downleg. The electrojet measurements showed a profile peaking at 1.3 x 105 cm-3 at 106 km. with large scale fluctuations having amplitudes of roughly 10 % seen only on the upward gradient in electron density. This is in agreement with plasma instability theory. We further show that simultaneous measurements by fixed-bias Langmuir probes, when normalized at a single point to the altitude profile of electron density, are inadequate to correctly parameterize the observed enhancements and depletions. (author)

162

Measurement of absolute excitation cross sections near threshold  

International Nuclear Information System (INIS)

Though many electron impact excitation cross sections have been measured with fair degrees of accuracy, often to several hundred eV above threshold, cross section measurements within the first 10 or 20 eV above threshold, (often the most important energy region for modeling calculations and particularly so for modeling of low energy plasmas) are particularly difficult to make with any degree of accuracy using conventional techniques. Though one can to some extent guess the functional shape of a cross section in this energy region, this is not a particularly desirable procedure. For example, while optically forbidden triplet states often have a maximum cross section near threshold due to charge exchange processes, optically allowed states tend to increase monotonically from threshold. However, the actual magnitude of cross sections are often governed by the presence of negative ion resonances lying energetically just below or above the threshold for excitation. Recently, we hav employed a modified version of the so-called trapped electron method to measure for the first time the total (with respect to angle) individual excitation functions of the 3S, 1S, 3P and 1P states of He to about 4 or 5 eV above their respective thresholds with high resolution. 8 references

163

Absolute density measurements by dual sinker magnetic levitation densimeter  

Science.gov (United States)

The use of a magnetic levitation densimeter (MLD) currently represents the most sensitive way of measuring fluid density for a wide range of temperature and pressure conditions. However, due to magnetic force transmission errors, the accuracy of this approach is limited to approximately 100 ppm in density. Here, the authors propose an improved method to eliminate the uncertainty caused by magnetic forces acting on fluids based on the use of dual sinkers and control of the magnetic coupling's levitation height. The technique cuts out almost all force transmission errors and enables a level of density measurement precision better than 1 ppm. A new high-sensitivity MLD system was developed using a novel sinker exchange mechanism with a magnetic coupling. Single-crystal silicon and germanium were selected as the sinker materials because of their outstanding performance in terms of isotropy, stability and universality of thermophysical properties. A number of tests to check the measurement performance of the MLD were conducted by the National Metrology Institute of Japan. The experimental results for n-tridecane are also presented in this paper.

Kayukawa, Y.; Kano, Y.; Fujii, K.; Sato, H.

2012-08-01

164

Alpha radioactivity measurements in tobacco leaves  

International Nuclear Information System (INIS)

Smoking is hazardous to your health, warning labels such as this appear on every pack of cigarettes sold in the country. The link between cigarette smoke and cancer has long been established. Smokers are ten times at greater risk of developing lung cancer than that of non-smokers. Tobacco plants were grown using different types of chemical fertilizers in different amounts just before the plantation is done in some cases while after an interval of one month in other cases. The alpha radioactivity of the leaves of these plants was measured using plastic track detectors LR-115 Type-II manufactured by Kodak. Measurement of track densities (track cm-2 day) shows a variation from 15.2 track cm-2 day-1 to 38.6 track cm-2 day-1 on the upper face and 20.7 track cm-2 day-1 to 45.4 track cm-2 day-1 at the bottom face for the plants in which fertilizers were added to soil just before the plantation while it varied from 6.9 track cm-2 day-1 to 35.8 track cm-2 day-1 and 17.9 to 41.3 track cm-2day-1 respectively on the upper and bottom faces for those plants in which fertilizers were added at a later stage. These variations are on higher side as compared to the plants grown without any use of fertilizer has been established. (author)

165

The Implications for Higher-Accuracy Absolute Measurements for NGS and its GRAV-D Project  

Science.gov (United States)

Absolute and relative gravity measurements play an important role in the work of NOAA's National Geodetic Survey (NGS). When NGS decided to replace the US national vertical datum, the Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project added a new dimension to the NGS gravity program. Airborne gravity collection would complement existing satellite and surface gravity data to allow the creation of a gravimetric geoid sufficiently accurate to form the basis of the new reference surface. To provide absolute gravity ties for the airborne surveys, initially new FG5 absolute measurements were made at existing absolute stations and relative measurements were used to transfer those measurements to excenters near the absolute mark and to the aircraft sensor height at the parking space. In 2011, NGS obtained a field-capable A10 absolute gravimeter from Micro-g LaCoste which became the basis of the support of the airborne surveys. Now A10 measurements are made at the aircraft location and transferred to sensor height. Absolute and relative gravity play other roles in GRAV-D. Comparison of surface data with new airborne collection will highlight surface surveys with bias or tilt errors and can provide enough information to repair or discard the data. We expect that areas of problem surface data may be re-measured. The GRAV-D project also plans to monitor the geoid in regions of rapid change and update the vertical datum when appropriate. Geoid change can result from glacial isostatic adjustment (GIA), tectonic change, and the massive drawdown of large scale aquifers. The NGS plan for monitoring these changes over time is still in its preliminary stages and is expected to rely primarily on the GRACE and GRACE Follow On satellite data in conjunction with models of GIA and tectonic change. We expect to make absolute measurements in areas of rapid change in order to verify model predictions. With the opportunities presented by rapid, highly accurate absolute gravimetry, we expect that GRAV-D may be affected in a number of ways. 1) Areas requiring re-measurement as a result of poor quality data or temporal change could be measured with such a new meter. With a meter capable of field measurement with observation times that are very short, surveys previously conducted only with the relative meters could be performed with the absolute meter with no loss of time and a significant increase in accuracy. 2) Regions of rapid change due to hydrological change associated with aquifers could be measured and re-measured rather quickly. Such accuracy may provide more accurate snapshots of the aquifers over time. 3) NGS conducts absolute gravity comparisons at its Table Mountain facility for validating the performance of absolute meters through their co-located operation at gravity piers. An increase in accuracy of an order of magnitude may change the entire nature of absolute meter performance evaluation.

Childers, V. A.; Winester, D.; Roman, D. R.; Eckl, M. C.; Smith, D. A.

2013-12-01

166

High accuracy, absolute, cryogenic refractive index measurements of infrared lens materials for JWST NIRCam using CHARMS  

CERN Document Server

The refractive optical design of the James Webb Space Telescope (JWST) Near Infrared Camera (NIRCam) uses three infrared materials in its lenses: LiF, BaF2, and ZnSe. In order to provide the instrument's optical designers with accurate, heretofore unavailable data for absolute refractive index based on actual cryogenic measurements, two prismatic samples of each material were measured using the cryogenic, high accuracy, refraction measuring system (CHARMS) at NASA's Goddard Space Flight Center (GSFC), densely covering the temperature range from 15 to 320 K and wavelength range from 0.4 to 5.6 microns. Data reduction methods are discussed and graphical and tabulated data for absolute refractive index, dispersion, and thermo-optic coefficient for these three materials are presented for selected wavelengths and temperatures along with estimates of index uncertainty. Coefficients for temperature-dependent Sellmeier fits of measured index are also presented with an example of their usage to predict absolute index ...

Leviton, Douglas B; Kvamme, Todd

2008-01-01

167

METHODS FOR THE REALIZATION OF RADIOACTIVE STANDARDS AND FOR THE ENVIRONMENTAL RADIOACTIVITY MEASUREMENT  

Directory of Open Access Journals (Sweden)

Full Text Available The radionuclide metrology assures: the realization, the conservation and the transmission of the “activity” standards, in various fields of measurement, environmental radioactivity characterization being included. The Radionuclide Metrology Laboratory (RML, IFIN-HH, usually prepares radioactivity standards (reference materials, consisting from: standard solutions, point and large area alpha and beta standard sources, and gamma volume standard sources used for the measurement of environmental samples and for the calibration of surface contamination monitors.The most important measurement methods used in the environmental radioactivity measurements, developed in IFIN-HH, are: gross alpha and gross beta measurements and gamma-ray spectrometry measurements. The choice of the adequate method depends on several factors, such as: type of emitted radiation, existence of a single or mixture of radionuclides, physical shape of the matrix.The authors describe the methods for the realization of standard sources used for the calibration of equipment used in such monitoring and methods for the environmental radioactivity measurement.

ANDREI ANTOHE

2011-06-01

168

Fast analysis of the radioactivity measurement data based on bluetooth  

International Nuclear Information System (INIS)

Introduced the method that the bluetooth technique imbeds the radioactivity measurement instrument, and realized remote monitor and radioactivity measurement data quickly analysis through the use of the wireless technique-bluetooth and the portable handhold PC. Give the system design, the device select and connect, the circumstance of the software programming and actual debug. (authors)

169

Absolute distance measurement based on femtosecond frequency comb with wavelet transform  

Science.gov (United States)

Spectrally resolved interferometry based on optical frequency comb is an effective way for absolute distance measurement. We introduce wavelet transform to spectrally resolve interferometry as an effective data analysis tool. A comparison has been presented between wavelet transform and conventional algorithm. The results demonstrate that the wavelet transform is a reliable technique and provides good performance over noise resistance for spectrally resolved interferometry measurement.

Li, Yao; Hu, Kun; Ji, Rongyi; Liu, Deming; Zhou, Weihu

2014-12-01

170

Electrical Noise and the Measurement of Absolute Temperature, Boltzmann's Constant and Avogadro's Number.  

Science.gov (United States)

Describes an apparatus capable of measuring absolute temperatures of a tungsten filament bulb up to normal running temperature and measuring Botzmann's constant to an accuracy of a few percent. Shows that electrical noise techniques are convenient to demonstrate how the concept of temperature is related to the micro- and macroscopic world. (CW)

Ericson, T. J.

1988-01-01

171

Flowrate measurements in closed pipes by the method of transit time measurement. Pt.1 Method of transit time of a radioactive tracer  

International Nuclear Information System (INIS)

Classical methods of flowrate measuring in closed pipes generally make use of indirect principles (for example: the measurements of the pressure loss through an orifice plate). Absolute or fundamental methods of the measurements of volume and time allow the ''in situ'' calibration and control of flowmeters in their nominal conditions of use. The method of transit-time measurements by fast injection of a radioactive tracer is described and analyzed

172

Absolute rate measurements of two-photon process of gases, liquids, and solids  

International Nuclear Information System (INIS)

Due to rapid improvements in high-power laser performance, two-photon absorption processes have become a very useful tool for studying the molecular structures of various gases, liquids and solids. However, measurements of absolute two-photon absorption cross sections were more or less ignored previously because of their small size. In this work, we obtained not only the two-photon absorption spectra, but also measurements of their absolute cross sections for various gases, liquids, and solids. 8 refs., 1 fig., 1 tab

173

A flowrate measurement method by counting of radioactive particles suspended in a liquid  

International Nuclear Information System (INIS)

By external counting of fine #betta# emitting radioactive particles suspended in a liquid, the flowrate in a system of pipes can be measured. The study comprises three phases: 1. - The hydraulic validity of the method is demonstrated in laminar as well as in turbulent flow under certain conditions of particles size and density and of liquid viscosity. 2. - Radioactive labelling of microspheres of serumalbumin or ion exchange resins with indium 113m delivered by a generator Tin 113 ? Indium 113m. 3. - Counting with a scintillation detector: a method of threshold overstepping is experimented with a mechanical or electronic simulator; the statistical study of particle superposition under the detector enables a correction for the resulting counting losses to be proposed. The method provides absolute measurements, but is particularly suitable to measure relative flowrates in a hydraulic network. It can be continuous and does not perturb the flow and the network. The accuracy of the method is analysed in details

174

Absolute frequency measurements of wavelength standards 532 nm, 543 nm, 633 nm and 1540 nm  

Science.gov (United States)

This paper describes the results of absolute frequency measurements of primary wavelength standards 633 nm, 543 nm, 532 nm, (iodine stabilized) and 1540 nm (acetylene stabilized) in CMI. The values obtained with Menlo Systems femtosecond frequency comb in CMI are compared with previous measurements of the same standards in BIPM, BEV and MPQ. Measured sub-Doppler linewidths and relative intensities of several hyperfine spectral components of iodine molecule are also presented.

Balling, P.; K?en, P.

2008-06-01

175

Absolute Position Measurement in a Gas Time Projection Chamber via Transverse Diffusion of Drift Charge  

OpenAIRE

Time Projection Chambers (TPCs) with charge readout via micro pattern gaseous detectors can provide detailed measurements of charge density distributions. We here report on measurements of alpha particle tracks, using a TPC where the drift charge is amplified with Gas Electron Multipliers and detected with a pixel ASIC. We find that by measuring the 3-D topology of drift charge and fitting for its transverse diffusion, we obtain the absolute position of tracks in the drift d...

Lewis, P. M.; Vahsen, S. E.; Hedges, M. T.; Jaegle, I.; Seong, I. S.; Thorpe, T. N.

2014-01-01

176

On the absolute measure of Beta activities; Sobre la medida absoluta de actividades Beta  

Energy Technology Data Exchange (ETDEWEB)

A new method for absolute beta counting of solid samples is given. The measurements is made with an inside Geiger-Muller tube of new construction. The backscattering correction when using an infinite thick mounting is discussed and results for different materials given. (Author)

Sanchez del Rio, C.; Jimenez Reynaldo, O.; Rodriguez Mayquez, E.

1956-07-01

177

Low geometry counter for the absolute measurement of the activity of alpha-emitting sources  

International Nuclear Information System (INIS)

A low-geometry counter is described which allows the absolute determination of the activity for alpha-emitting sources. A Si implanted detector is used to obtain the spectrum of the sample. Two samples are measured with this counter and a 2 ? gridded ion chamber. The results an their uncertainties for both instruments are discussed. (Author)

178

Progress towards the measurement of absolute elastic electron-molecular radical scattering cross sections  

Energy Technology Data Exchange (ETDEWEB)

We report on our progress in developing a dedicated crossed beam apparatus, for the measurement of absolute cross sections for elastic scattering of electrons from molecular radicals. Features which are original to this apparatus will be highlighted, and a discussion of its current status and future developments provided.

Maddern, T M [ARC Centre of Excellence for Antimatter-Matter Studies, SoCPES, Flinders University, Adelaide (Australia); Hargreaves, L R [ARC Centre of Excellence for Antimatter-Matter Studies, SoCPES, Flinders University, Adelaide (Australia); Buckman, S J [ARC Centre of Excellence for Antimatter-Matter Studies, RSPhysSE, Australian National University, Canberra (Australia); Brunger, M J [ARC Centre of Excellence for Antimatter-Matter Studies, SoCPES, Flinders University, Adelaide (Australia)

2007-10-15

179

Measurement of the absolute branching ratio of the K+ ? ?+???+ (?) decay with the KLOE detector  

Science.gov (United States)

The absolute branching ratio of the K+ ? ?+???+ (?) decay, inclusive of final- state radiation, has been measured using ~17 million tagged K+ mesons collected with the KLOE detector at DA?NE, the Frascati phi-factory. The result is: BR(K+ ? ?+???+ (?)) = 0.05565 ± 0.00031stat ± 0.00025syst

de Simone, Patrizia; Kloe/Kloe-2 Collaboration

2014-11-01

180

Superharp: A wire scanner with absolute position readout for beam energy measurement at CEBAF  

International Nuclear Information System (INIS)

Superharp is an upgrade CEBAF wire scanner with absolute position readout from shaft encoder. As high precision absolute beam position probe (?x ? 10?m), three pairs of superharps are installed at the entrance, the mid-point, and the exit of Hall C arc beamline in beam switch yard, which will be tuned in dispersive mode as energy spectrometer performing 10-3 beam energy measurement. With dual sensor system: the direct current pickup and the bremsstrahlung detection electronics, beam profile can be obtained by superharp at wide beam current range from 1 ?A to 100 ?A

181

New absolute distance measurement technique with a self-mixing interferometer  

Energy Technology Data Exchange (ETDEWEB)

A new compact self-aligned noncontact range finder is described. It uses the self-mixing effect inside a laser diode. Double modulation technique is proposed to improve the measurement accuracy. Wavelength modulation (WM) of the laser beam is obtained by modulating the injection current of the laser diode. Phase modulation (PM) of the laser beam is obtained by an electro-optic crystal (EOC) in the external cavity. Absolute distance of the external target is determined by Fourier analysis method. Experimental results show that an accuracy of {+-}0.3mm can be achieved for absolute distance ranging from 277mm to 477mm.

Guo Dongmei; Wang Ming [JiangSu Key Lab on opto-electronic Technology, School of Physical Science and Technology, Nanjing Normal University, 210097, Nanjing (China)

2007-07-15

182

Re-creating Gauss's method for non-electrical absolute measurements of magnetic fields and moments  

Science.gov (United States)

In 1832, Gauss made the first absolute measurements of magnetic fields and of magnetic moments in experiments that are straightforward and instructive to replicate. We show, using rare-earth permanent magnets and a variation of Gauss's technique, that the horizontal component of the ambient geomagnetic field, as well as the size of the magnetic moments of such magnets, can be found. The method shows the connection between the SI and cgs emu unit systems for these quantities and permits an absolute realization of the Ampere with considerable precision.

Van Baak, D. A.

2013-10-01

183

Absolute photoionization cross section measurements of Xe+ ions in the 4d threshold energy region  

International Nuclear Information System (INIS)

Using the photon-ion merged-beam technique, we have measured the absolute photoionization cross sections for Xe2+ and Xe3+ formation from Xe+ at selected energies between 80 and 140 eV, and utilized the absolute data to normalize our previously reported relative cross sections. The structure and energy dependence of the cross sections for Xe+ deviate from those of neutral Xe; however, the maximum total cross section for Xe+ is, within the experimental error, the same as for Xe. (author)

184

Environmental radioactivity measurements at Mikamine, Sendai  

International Nuclear Information System (INIS)

The Fukushima 1 Nuclear Power Plant suffered major damage from the 2011 off the Pacific coast of Tohoku Earthquake and subsequent tsunami on March 11, 2011 and released various radionuclides. Monitoring of environmental radioactivity should provide important information on the behavior of the radionuclides. In this presentation, the monitoring results on the concentration of radioactivity in the air and soil and the radiation dose rate are shown. In addition, the Electron Linear Accelerator at Research Center for Electron Photon Science, Tohoku University also suffered damage from the earthquake. The state and the reconstruction plan of the accelerator will be presented. (author)

185

Measurement of Absolute Hadronic Branching Fractions of D_s Mesons  

CERN Document Server

We report preliminary measurements of absolute hadronic branching fractions of Ds mesons determined using a double tag technique. These measurements are from 195 pb^{-1} of e+e- collisions recorded at center of mass energies near 4.17 GeV with the CLEO-c detector at CESR. We obtain absolute branching fractions for Ds+ decays to KS0 K+, K- K+ pi+, K- K+ pi+ pi-, pi+ pi+ pi-, pi+ eta, and pi+ etaprime. We discuss the problems inherent in measuring accurately the branching fraction for Ds+ to phi pi+, which is often used as a reference mode for measurement of other Ds+ branching fractions, and provide a measurement of a branching fraction that may be useful for this purpose.

Adam, N; Berkelman, K; Cassel, D G; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Onyisi, P U E; Patterson, J R; Peterson, D; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Weinberger, M; Athar, S B; Patel, R; Potlia, V; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; White, E J; Wiss, J; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Smith, A; Zweber, P; Dobbs, S; Metreveli, Z V; Seth, K K; Tomaradze, A G; Ernst, J; Severini, H; Dytman, S A; Love, W; Savinov, V; Aquines, O; Li, Z; López, A; Mehrabyan, S S; Méndez, H; Ramírez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Coan, T E; Gao, Y S; Liu, F; Artuso, M; Blusk, S; Butt, J; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Briere, R A; Brock, I; Chen, J; Ferguson, T; Tatishvili, G T; Vogel, H; Watkins, M E; Rosner, J L

2006-01-01

186

High Accuracy, Absolute, Cryogenic Refractive Index Measurements of Infrared Lens Materials for JWST NIRCam using CHARMS  

Science.gov (United States)

The current refractive optical design of the James Webb Space Telescope (JWST) Near Infrared Camera (NIRCam) uses three infrared materials in its lenses: LiF, BaF2, and ZnSe. In order to provide the instrument s optical designers with accurate, heretofore unavailable data for absolute refractive index based on actual cryogenic measurements, two prismatic samples of each material were measured using the cryogenic, high accuracy, refraction measuring system (CHARMS) at NASA GSFC, densely covering the temperature range from 15 to 320 K and wavelength range from 0.4 to 5.6 microns. Measurement methods are discussed and graphical and tabulated data for absolute refractive index, dispersion, and thermo-optic coefficient for these three materials are presented along with estimates of uncertainty. Coefficients for second order polynomial fits of measured index to temperature are provided for many wavelengths to allow accurate interpolation of index to other wavelengths and temperatures.

Leviton, Douglas; Frey, Bradley

2005-01-01

187

Results of radioactivity measurements on foodstuffs in Romania  

International Nuclear Information System (INIS)

There are presented the results of gamma-spectrometric measurements performed between 1986-1995 on: milk and dairy products; meat and meat products; fish; wheat flour; fresh fruits and vegetables. The foodstuffs are sampled from some representative areas like: Bucharest, Bechet (affected by Kozloduj NPP, Bulgaria), Cernavoda, middle of Transylvania, Neamt. The radioactivity measurements are performed by high-resolution ?-ray spectrometry. There are identified and analysed mainly 134Cs, 137Cs, 40K and, sometimes, other radionuclides. There are pointed out: the constancy of natural radionuclides amounts; the drastic increasing in radioactive concentration in May 1986; the seasonal variation of radioactivity in some food items; the time - exponential diminution of radioactivity in 1991-1995; and the maximum permitted levels of radioactive contamination of foodstuffs following a nuclear accident. (author)

188

Glacial mass balance determination in the accumulation zone by in situ measurements of Chernobyl radioactivity  

International Nuclear Information System (INIS)

Radioactive fallout from atmospheric thermo-nuclear tests conducted in 1954 and 1962-1963, and more recently from the Chernobyl accident on 26 April 1986, provide markers, or well-known levels, in the snow layers of the north hemisphere glacier accumulation zones. The design and operation of the in situ measurement of gamma rays from cesium-137 (662 KeV) in ice bore-holes allows rapid detection in the field of the Chernobyl radioactive layer of snow. The validity of this detection method is much enhanced due to the 29.5 year half-life of cesium-137. These measurements indicate the absolute dating of snow layers deposited since May 1986; they give the spatio-temporal variations of glacial mass balance, as well as fallout amounts of radio-isotopes

189

Introducing an Absolute Cavity Pyrgeometer for Improving the Atmospheric Longwave Irradiance Measurement (Presentation)  

Energy Technology Data Exchange (ETDEWEB)

Advancing climate change research requires accurate and traceable measurement of the atmospheric longwave irradiance. Current measurement capabilities are limited to an estimated uncertainty of larger than +/- 4 W/m2 using the interim World Infrared Standard Group (WISG). WISG is traceable to the Systeme international d'unites (SI) through blackbody calibrations. An Absolute Cavity Pyrgeometer (ACP) is being developed to measure absolute outdoor longwave irradiance with traceability to SI using the temperature scale (ITS-90) and the sky as the reference source, instead of a blackbody. The ACP was designed by NREL and optically characterized by the National Institute of Standards and Technology (NIST). Under clear-sky and stable conditions, the responsivity of the ACP is determined by lowering the temperature of the cavity and calculating the rate of change of the thermopile output voltage versus the changing net irradiance. The absolute atmospheric longwave irradiance is then calculated with an uncertainty of +/- 3.96 W/m2 with traceability to SI. The measured irradiance by the ACP was compared with the irradiance measured by two pyrgeometers calibrated by the World Radiation Center with traceability to the WISG. A total of 408 readings was collected over three different clear nights. The calculated irradiance measured by the ACP was 1.5 W/m2 lower than that measured by the two pyrgeometers that are traceable to WISG. Further development and characterization of the ACP might contribute to the effort of improving the uncertainty and traceability of WISG to SI.

Reda, I.; Hansen, L.; Zeng, J.

2012-08-01

190

Frequency-scanning interferometry for dynamic absolute distance measurement using Kalman filter.  

Science.gov (United States)

We propose a frequency-scanning interferometry using the Kalman filtering technique for dynamic absolute distance measurement. Frequency-scanning interferometry only uses a single tunable laser driven by a triangle waveform signal for forward and backward optical frequency scanning. The absolute distance and moving speed of a target can be estimated by the present input measurement of frequency-scanning interferometry and the previously calculated state based on the Kalman filter algorithm. This method not only compensates for movement errors in conventional frequency-scanning interferometry, but also achieves high-precision and low-complexity dynamic measurements. Experimental results of dynamic measurements under static state, vibration and one-dimensional movement are presented. PMID:25503050

Tao, Long; Liu, Zhigang; Zhang, Weibo; Zhou, Yangli

2014-12-15

191

Reprocessing of GPS and Repeated Absolute Gravity Measurements Realized in the Tatra Mountain  

Science.gov (United States)

Long time series of position and gravity were monitored for determination of vertical velocities in the Tatra Mountain. All results were combined and compared to the present trend of global loading effects in the locality of the Tatra Mountain. The GPS measurements started in 1998 at 11 sites in the frame of CERGOP-2/Environmental Project and were reprocessed by standard procedure using Bernese software 5.0. Repeated absolute gravity measurements started in 2003 at 3 sites and were processed by standard Micro-g software. These results are compared to influence of the local environmental signals. The measurements were organized by Slovak University of Technology in Bratislava with cooperation of Warsaw University of Technology. The paper presents results of combination process GPS and absolute gravity measurements for the determination of the vertical movements.

Mojzes, M.; Papco, J.; Mikolaj, M.

2012-04-01

192

A novel method for the absolute fluorescence yield measurement by AIRFLY  

CERN Document Server

One of the goals of the AIRFLY (AIR FLuorescence Yield) experiment is to measure the absolute fluorescence yield induced by electrons in air to better than 10% precision. We introduce a new technique for measurement of the absolute fluorescence yield of the 337 nm line that has the advantage of reducing the systematic uncertainty due to the detector calibration. The principle is to compare the measured fluorescence yield to a well known process - the Cerenkov emission. Preliminary measurements taken in the BFT (Beam Test Facility) in Frascati, Italy with 350 MeV electrons are presented. Beam tests in the Argonne Wakefield Accelerator at the Argonne National Laboratory, USA with 14 MeV electrons have also shown that this technique can be applied at lower energies.

Ave, M

2008-01-01

193

Measurements of radioactive dusts at high altitude. Special investigation  

International Nuclear Information System (INIS)

For the nuclear explosion test conducted by North Korea on October 9 in 2006, the radioactive nuclides etc. contained in the airborne dust collected at high altitude by the Japan Air Self-Defence Force in the spatial investigation were measured. The artificial radioactive nuclides such as caesium and radioactive gas (gaseous radioiodine) were not detected. In addition, from the results of the gross beta activity measurement at high altitude in our country, it was shown that there is no appreciable difference between the activity levels of this period and those of usual periods. (author)

194

Adjustment of a two-block X-ray interferometer and absolute measurement of lattice spacing  

International Nuclear Information System (INIS)

X-ray interferometer was invented in 1965 by Bonse and Hart, and it uses the lattice surface of a silicon single crystal as a three-dimensional diffraction lattice. It divides X-ray coherently, changes direction, combines and causes interference. It made for the first time the interference effect of X-ray into the usable form in macroscopic world. As an example of the application of X-ray interferometers to basic science, there is the absolute measurement of lattice spacing. This is the method of simultaneously measuring the same displacement with an X-ray interferometer and a light wave interferometer, and doing the absolute measurement of the lattice spacing of crystals with light wavelength. Avogadro constant is the constant that becomes the foundation of chemistry, and its relation with other basic constants is shown. The principle of X-ray interferometers is explained. As the elementary technologies for the absolute measurement of lattice spacing, the adjustment of X-ray interferometers, parallel movement table and angular adjustment table, light wave interferometer and the prevention of vibration and temperature change are described. The example of the measurement is reported. In order to improve the accuracy, the improvement of the equipment and the measurement in vacuum are prepared at present. (K.I.)

195

Relative Gravity Measurement Campaign during the 7th International Comparison of Absolute Gravimeters (2005)  

Science.gov (United States)

Since the 1st International Comparison of Absolute Gravimeters (ICAG) and accompanying Relative Gravity Campaign (RGC) held at the BIPM in 1981, repeated ICAG-RGCs have been organized every four years. A total of 19 absolute gravimeters (AG) and 15 relative gravimeters (RG) participated in the 7th ICAG-RGC, which took place in 2005. Co-located absolute and relative gravity measurements as well as precision levelling measurements were carried out. The final version of the absolute g values of the 7th ICAG has been officially released recently. This paper is the final report of the 7th RGC and replaces the preliminary results published earlier. It covers the organization of the RGC and the data processing, analyses RG behaviour, computes g, ?g and OAG (offset of AG) and discusses their uncertainties. In preparation for the BIPM key comparison ICAG-2009, a standard data-processing procedure has been developed and installed in the BIPM ICAG-RGC software package, GraviSoft. This was used for the final data processing.

Jiang, Z.; Becker, M.; Francis, O.; Germak, A.; Palinkas, V.; Jousset, P.; Kostelecky, J.; Dupont, F.; Lee, C. W.; Tsai, C. L.; Falk, R.; Wilmes, H.; Kopaev, A.; Ruess, D.; Ullrich, M. C.; Meurers, B.; Mrlina, J.; Deroussi, S.; Métivier, L.; Pajot, G.; Santos, F. Pereira Dos; van Ruymbeke, M.; Naslin, S.; Ferry, M.

2009-06-01

196

Determination of collagen fibril size via absolute measurements of second-harmonic generation signals  

Science.gov (United States)

The quantification of collagen fibril size is a major issue for the investigation of pathological disorders associated with structural defects of the extracellular matrix. Second-harmonic generation microscopy is a powerful technique to characterize the macromolecular organization of collagen in unstained biological tissues. Nevertheless, due to the complex coherent building of this nonlinear optical signal, it has never been used to measure fibril diameter so far. Here we report absolute measurements of second-harmonic signals from isolated fibrils down to 30?nm diameter, via implementation of correlative second-harmonic-electron microscopy. Moreover, using analytical and numerical calculations, we demonstrate that the high sensitivity of this technique originates from the parallel alignment of collagen triple helices within fibrils and the subsequent constructive interferences of second-harmonic radiations. Finally, we use these absolute measurements as a calibration for ex vivo quantification of fibril diameter in the Descemet’s membrane of a diabetic rat cornea.

Bancelin, Stéphane; Aimé, Carole; Gusachenko, Ivan; Kowalczuk, Laura; Latour, Gaël; Coradin, Thibaud; Schanne-Klein, Marie-Claire

2014-09-01

197

Absolute measurements of electron impact excitation cross-sections of atoms using cavity ringdown spectroscopy  

Science.gov (United States)

A new method of using cavity ringdown spectroscopy (CRDS) technique to measure apparent electron impact excitation cross-sections (EIECS) for different energy levels of an atom is described. The method involves measurements of absolute population densities of the energy levels in concern using the high sensitivity CRDS, leading to an analytical expression of EIECS as a function of the population densities. Determination of EIECS in this method does not require an external calibration. The proposed method is validated by determining EIECS of the metastable levels of Hg (6s6p 3P0) and Ne (2p53s 3P2), and the results are in good agreement with the cross-sections reported in the literature. The population densities in both cases were extracted from the published data. This method exhibits promising potential for absolute measurements of EIECS of metastable energy levels.

Sahay, Peeyush; Wang, Chuji

2015-01-01

198

Measuring the absolute DT neutron yield using the Magnetic Recoil Spectrometer at OMEGA and the NIF  

International Nuclear Information System (INIS)

A Magnetic Recoil Spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion (ICF) implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

199

Measurement of absolute Al concentration in AlxGa1-xAs  

International Nuclear Information System (INIS)

A technique has been developed to measure the absolute Al concentration x in AlxGa1-xAs. The technique involves simultaneous measurements of the 27Al(p,?)28Si resonant nuclear reaction and Rutherford backscattering (RBS), and comparisons with an AlAs reference sample. A detailed description of the experimental procedure is given. Samples analyzed in this study were prepared by LPE and MOVPE growth on GaAs substrates, with expitaxial layer thicknesses in the range 1-3 ?m and Al concentrations in the range 0.10< x<0.85. Measurements of x with an absolute error <0.02 were obtained. Factors limiting the precision obtainable with this technique are discussed. (orig.)

200

Introducing an Absolute Cavity Pyrgeometer (ACP) for Improving the Atmospheric Longwave Irradiance Measurement (Poster)  

Energy Technology Data Exchange (ETDEWEB)

Advancing climate change research requires accurate and traceable measurement of the atmospheric longwave irradiance. Current measurement capabilities are limited to an estimated uncertainty of larger than +/- 4 W/m2 using the interim World Infrared Standard Group (WISG). WISG is traceable to the Systeme international d'unites (SI) through blackbody calibrations. An Absolute Cavity Pyrgeometer (ACP) is being developed to measure absolute outdoor longwave irradiance with traceability to SI using the temperature scale (ITS-90) and the sky as the reference source, instead of a blackbody. The ACP was designed by NREL and optically characterized by the National Institute of Standards and Technology (NIST). Under clear-sky and stable conditions, the responsivity of the ACP is determined by lowering the temperature of the cavity and calculating the rate of change of the thermopile output voltage versus the changing net irradiance. The absolute atmospheric longwave irradiance is then calculated with an uncertainty of +/- 3.96 W/m2 with traceability to SI. The measured irradiance by the ACP was compared with the irradiance measured by two pyrgeometers calibrated by the World Radiation Center with traceability to the WISG.

Reda, I.; Stoffel, T.

2012-03-01

201

High-precision gravity measurements using absolute and relative gravimeters at Mount Etna (Sicily, Italy  

Directory of Open Access Journals (Sweden)

Full Text Available Accurate detection of time gravity changes attributable to the dynamics of volcanoes requires high-precision gravity measurements. With the aim of improving the quality of data from the Mount Etna gravity network, we used both absolute and relative gravimeters in a hybrid method. In this report, some of the techniques for gravity surveys are reviewed, and the results related to each method are compared. We show how the total uncertainty estimated for the gravity measurements performed with this combined use of absolute and relative gravimeters is roughly comparable to that calculated when the measurements are acquired using only relative gravimeters (the traditional method. However, the data highlight how the hybrid approach improves the measurement capabilities for surveying the Mount Etna volcanic area. This approach enhances the accuracy of the data, and then of the four-dimensional surveying, which minimizes ambiguities inherent in the gravity measurements. As a case study, we refer to two gravity datasets acquired in 2005 and 2010 from the western part of the Etna volcano, which included five absolute and 13 relative stations of the Etna gravity network.

Ciro Del Negro

2011-12-01

202

Spectrally integrated window transmittance measurements for a cryogenic solar absolute radiometer  

Science.gov (United States)

A recently built cryogenic solar absolute radiometer aims to reduce the uncertainty of terrestrially measured direct solar irradiance from 0.3% to 0.01%. Because solar irradiance entering a cryogenic radiometer is partly reflected and absorbed by the entrance window, the spectrally integrated transmittance of the broadband solar irradiance needs to be determined in parallel to correct the power reading of the cryogenic radiometer for these losses. To meet the accuracy requirements of the radiometer, the Monitor to Measure the Integral Transmittance of Windows (MITRA) aims to measure the spectrally integrated transmittance of a window identical to that used for the cryogenic radiometer with an uncertainty of less than 0.01%. The current model of the MITRA instrument measures transmittances with an instrument stability of 0.015% under laboratory conditions, almost achieving the instrument requirement. This proves that the accuracy of terrestrial irradiance measurements can be significantly increased by means of a cryogenic solar absolute radiometer, which can then be utilized as a new calibration standard for terrestrial absolute radiometry.

Walter, Benjamin; Fehlmann, André; Finsterle, Wolfgang; Suter, Markus; Soder, Ricco; Schmutz, Werner

2014-12-01

203

Temperature-dependent Absolute Refractive Index Measurements of Synthetic Fused Silica  

Science.gov (United States)

Using the Cryogenic, High-Accuracy Refraction Measuring System (CHARMS) at NASA's Goddard Space Flight Center, we have measured the absolute refractive index of five specimens taken from a very large boule of Corning 7980 fused silica from temperatures ranging from 30 to 310 K at wavelengths from 0.4 to 2.6 microns with an absolute uncertainty of plus or minus 1 x 10 (exp -5). Statistical variations in derived values of the thermo-optic coefficient (dn/dT) are at the plus or minus 2 x 10 (exp -8)/K level. Graphical and tabulated data for absolute refractive index, dispersion, and thermo-optic coefficient are presented for selected wavelengths and temperatures along with estimates of uncertainty in index. Coefficients for temperature-dependent Sellmeier fits of measured refractive index are also presented to allow accurate interpolation of index to other wavelengths and temperatures. We compare our results to those from an independent investigation (which used an interferometric technique for measuring index changes as a function of temperature) whose samples were prepared from the same slugs of material from which our prisms were prepared in support of the Kepler mission. We also compare our results with sparse cryogenic index data from measurements of this material from the literature.

Leviton, Douglas B.; Frey, Bradley J.

2006-01-01

204

Scintillation Method for Measuring the Radioactivity of 55Fe  

International Nuclear Information System (INIS)

A double-channel 4? scintillation counter containing two photomultipliers (E.M.I.-9514S), a light-pipe and two plastic scintillators (NE-102) in sandwich form with the source between them was used as a detector. The source was prepared on transparent mylar foil and covered by another layer of the foil. The counting equipment counted the pulses from the detector in both the parallel and coincidence systems. The scintillation counter was cooled to -20°C, because of the dark current from the photomultipliers. The anode characteristics of the scintillation counter for 55Fe and for the background are given, which enabled the proper working parameters to be chosen. Full absorption of the Auger electrons in the mylar foil being taken into account, the measurements of the counting efficiency for K X-rays as a function of the thickness of the plastic scintillators (from 0.45 mm to 3.5 mm) are presented. The proper scintillator thickness, ensuring full absorption of K X-rays, has been chosen for further measurements. The measurements of the amount of K X-rays from the sample were performed by taking the discrimination curves (for constant EHT and gain of amplification) and extrapolation to the zero level of discrimination. The amount of the counted K X-rays from the sample was taken as a basis to calculate the radioactive concentration of the 55Fe solution. The absorption correction for K X-rays in the mylar foil was defined experimentally. The results oas defined experimentally. The results of parallel system measurements of IAEA and Amersham standard solutions were compared with the figures given by the producers. The counting efficiency of the K X-rays in the coincidence system was calculated and compared with the results obtained from the parallel system. The results obtained showed that the parallel system of counting can be used as the absolute method for the ssFe solutions and the coincidence system as the relative one. (author)

205

Precise measurement of radioactivity only possible in a laboratory  

International Nuclear Information System (INIS)

Radioactivity is often measured using simple allround radiation meters that measure doses or dose rates. Sometimes, however, there is a need for more accurate information on the quality or quantity of radioactive substances. A sample is then taken for measurement in a laboratory. Laboratories use gamma spectrometers or other specially developed equipment for identifying radioactive substances and for measuring their precise contents. Portable radiation meters usually have a Geiger tube or a scintillation crystal as a detector. The detector is sensitive to gamma and beta radiation. The display of modern meters shows the dose rate as microsieverts per hour or the dose as millisieverts. Owing to nature's own radioactive materials and cosmic radiation from space, the reading of an allround radiation meter is never exactly zero. The dose rate caused by natural background radiation in Finland is 0.05-0.20 microSv/h. The reading varies, depending on soil quality, the season of the year and the weather conditions. For this reason, repeated measurements in the same locality may produce different results at different times. Measurement of the dose rate alone is not always enough; a more detailed analysis is needed of the object under study. A spectrometer reveals the radioactive substances, radionuclides, in the object. A spectrometer can also be used to determine the concentrations of radionuclides, and it is particularly useful for measuring samples. The concentrations of sevasuring samples. The concentrations of several nuclides can be determined simultaneously during one measurement, without advance preparation of the sample. (author)

206

Temperature-dependent absolute refractive index measurements of synthetic fused silica  

CERN Document Server

Using the Cryogenic, High-Accuracy Refraction Measuring System (CHARMS) at NASA's Goddard Space Flight Center, we have measured the absolute refractive index of five specimens taken from a very large boule of Corning 7980 fused silica from temperatures ranging from 30 to 310 K at wavelengths from 0.4 to 2.6 microns with an absolute uncertainty of +/-1 x 10^-5. Statistical variations in derived values of the thermo-optic coefficient (dn/dT) are at the +/-2 x 10^-8/K level. Graphical and tabulated data for absolute refractive index, dispersion, and thermo-optic coefficient are presented for selected wavelengths and temperatures along with estimates of uncertainty in index. Coefficients for temperature-dependent Sellmeier fits of measured refractive index are also presented to allow accurate interpolation of index to other wavelengths and temperatures. We compare our results to those from an independent investigation (which used an interferometric technique for measuring index changes as a function of temperatur...

Leviton, Douglas B

2008-01-01

207

Absolute measurement of effective atomic number and electron density using dual-energy computed tomography images  

Science.gov (United States)

The dual-energy computed tomography (CT) techniques can be adopted to separate the materials having similar Houndsfield Unit (HU) value such as tissues. In the technique, CT image values can be described as effective atomic number and electron density using the dual-energy equation. In this work, we measured effective atomic number and electron density using dual-energy CT images and assessed the image quality in vascular application. For the effective atomic number assessment, the measurements of a Polymethyl methacrylate (PMMA) and water demonstrated small discrepancies of 3.28 % and 5.56 %, respectively. For electron density measurement, the experimental errors of PMMA and water were 7.83 % and 4.00 %, respectively. The trend obtained when comparing the HU values and absolute values such as effective atomic number and electron density demonstrates that the CNR of the HU values is higher than that of the absolute values such as effective atomic number and electron density. With contrast media having low concentration, it is remarkable that the effective atomic number image occasionally has higher CNR values than the HU images. In this study, small discrepancies between the experimental values and known values were obtained. The CNR values provided meaningful results for the absolute measurements in a dual-energy CT technique.

Kim, Dae-Hong; Kim, Hee-Joung; Lee, Chang-Lae; Cho, Hyo-Min; Park, Hye-Suk; Lee, Seung-Wan; Choi, Yu-Na; Kim, Ye-Seul; Park, Su-Jin

2012-03-01

208

Measurements of natural radioactivity inside Dandara temple  

International Nuclear Information System (INIS)

The natural radioactivities inside Dandara temple are studied by using a NaI(Tl) scintillation spectrometer. The variation of these activities with location is investigated. Average values of the identified radionuclides inside the halls, sanctuary and crypt of the temple are examined. It is estimated that the mean value lies in the range 37.9-90.1 for 212Pb, 70.0-36.0 for 214Bi, 52.6-76.2 for 228 Ac, 1.6-5.9 for 208 Tl, while for 40K it is 169.3-286.6. (author)

209

Hyperspectral interferometry for single-shot absolute measurement of 3-D shape and displacement fields  

Directory of Open Access Journals (Sweden)

Full Text Available We propose a method that we call Hyperspectral Interferometry (HSI to resolve the 2? phase unwrapping problem in the analysis of interferograms recorded with a narrow-band light source. By using a broad-band light source and hyperspectral imaging system, a set of interferograms at different wavenumbers are recorded simultaneously on a high resolution image sensor. These are then assembled to form a three-dimensional intensity distribution. By Fourier transformation along the wavenumber axis, an absolute optical path difference is obtained for each pixel independently of the other pixels in the field of view. As a result, interferograms with spatially distinct regions are analysed as easily as continuous ones. The approach is illustrated with a HSI system to measure 3-D profiles of optically smooth or rough surfaces. Compared to existing profilometers able to measure absolute path differences, the single shot nature of the approach provides greater immunity from environmental disturbance.

Ruiz P. D.

2010-06-01

210

The absolute free-volume fraction in polymers from positron lifetime measurements  

International Nuclear Information System (INIS)

The summary of annihilation experiments of 6 simple elastomers in wide temperature interval of (15 - 370) K is presented. It is shown that combined use of positron annihilation lifetime spectroscopy (PAL) and dilatometry (specific volume measurement) provides the temperature dependence of absolute value of fraction of free volume f (T) and a unique information on thermal expansion coefficient of occupied volume ?0. The proposed model allows the determination of absolute value of occupied volume V0. In the case of poly(isobutylene) and cis-trans 1,4 poly(butadiene) results from PAL are compared with that obtained from the viscosity and the temperature shift parameter measurements. This comparison indicates that the positron annihilation reflects the same basic mechanism as the viscosity and relaxation processes. (orig.)

211

High-precision absolute distance measurement using dual-laser frequency scanned interferometry under realistic conditions  

International Nuclear Information System (INIS)

In this paper, we report on new high-precision absolute distance measurements performed with frequency scanned interferometry using a pair of single-mode optical fibers. Absolute distances were determined by counting the interference fringes produced while scanning the frequencies of the two chopped lasers. High-finesse Fabry-Perot interferometers were used to determine frequency changes during scanning. Dual lasers with oppositely scanning directions, combined with a multi-distance-measurement technique previously reported, were used to cancel drift errors and to suppress vibration effects and interference fringe uncertainties. Under realistic conditions, a precision about 0.2?m was achieved for a distance of 0.41m. With a precision that exceeds requirements, the frequency scanned interferometry is a promising high-precision optical alignment technique for International Linear Collider silicon tracker detector

212

Measurements of radioactive dusts in high altitude air  

International Nuclear Information System (INIS)

The radioactivities of airborne dust in samples were measured. The samples had been collected at high altitude by the Japan Air Self-Defense Force from April 2004 to March 2005. The data were obtained for the gross beta activity, gamma nuclide determination and radiochemical analysis. It is shown that there is no appreciable difference between the activity levels of this time and ones of the year before. Seasonal variations are little pronounced. It is found that the radioactivity have been stable in the low level at high altitude. Radioactive gas (gaseous radioiodine) was not detected. (author)

213

Measurements of radioactive dusts in high altitude air  

International Nuclear Information System (INIS)

The radioactively of airborne dust in samples collected by aircraft of the Japan Air Self-Defense Force at high altitude during the period between April 2001 to March 2002 were measured. The data of the gross beta activity, gamma nuclide determination and radiochemical analysis show that there is no appreciable difference from the activity levels of the year before. Seasonal variations are becoming less pronounced and this shows that the low level radioactivity at high altitude is stable. Radioactive gas (gaseous radioiodine) was not detected. (author)

214

Measurements of radioactive dusts in high altitude air  

International Nuclear Information System (INIS)

The radioactivities of airborne dust in samples were measured. The samples had been collected at high altitude by the Japan Air Self-Defense Force from April 2002 to March 2003. The data were obtained for the gross beta activity, gamma nuclide determination and radiochemical analysis. It is shown that there is no appreciable difference between the activity levels of this time and ones of the year before. Seasonal variations are little pronounced. The radioactivity is stable in the low level at high altitude. Radioactive gas (gaseous radioiodine) was not detected. (author)

215

Measurements of radioactive dust in high altitude air  

International Nuclear Information System (INIS)

The radioactivities of airborne dust in samples were measured. The samples had been collected at high altitude by the Japan Air Self-Defense Force from April 2009 to March 2010. The data were obtained for the gross beta activity, gamma nuclide determination and radiochemical analysis. It was shown that there was no appreciable difference between the activity levels of this time and in the year before. Seasonal variations were not very pronounced. It is found that the radioactivity has been stable at a low level at high altitude. Radioactive gas (gaseous radioiodine) was not detected. (author)

216

Trace elements and radioactivity measurements in Tunisia  

International Nuclear Information System (INIS)

This work is a part of an undergoing activity at the radioanalytical laboratory at the National Center of Nuclear Science and Technology in Tunisia aiming at studying natural and man-made radioactivity and trace elements in environmental and industrial samples in the country. Several samples of environmental concern were analysed for radioactivity concentrations of 238U, 232Th, 40K and 137Cs. The environmental samples included clay soils and beach-sands from the north and the south of the country and the sahara in Tunisia, food products, and water samples and sediments from the Mediterranean sea. Technological products that may pose a radiological risk to the population included construction material such as cement, bricks and gravel, and phosphate products and by products such as phosphogypsum. The analytical methods employed were high-resolution gamma-spectrometry, instrumental neutron activation analysis and inductively coupled plasma mass spectrometry. Results from the techniques employed are compared in terms of their accuracy, uncertainty and feasibility of performance in developing countries. The objectives are three fold: 1. To determine the concentrations of radioelement in environmental and industrial samples. 2. To investigate the impact of industrial and human activities on environmental pollution. 3. To compare several analytical techniques in terms of accuracy, uncertainty and feasibility. From the result, we can conclude that exposure to NORM and artifi conclude that exposure to NORM and artificial radiation from the samples analysed does not represent any major to human health

217

Absolute Frequency Measurement of Rubidium 5S-7S Two-Photon Transitions  

OpenAIRE

We report the absolute frequency measurements of rubidium 5S-7S two-photon transitions with a cw laser digitally locked to an atomic transition and referenced to an optical frequency comb. The narrow, two-photon transition, 5S-7S (760 nm) insensitive to first order in a magnetic field, is a promising candidate for frequency reference. The performed tests yield the transition frequency with accuracy better than reported previously.

Morzynski, Piotr; Wcislo, Piotr; Ablewski, Piotr; Gartman, Rafal; Gawlik, Wojciech; Maslowski, Piotr; Nagorny, Bartlomiej; Ozimek, Filip; Radzewicz, Czeslaw; Witkowski, Marcin; Ciurylo, Roman; Zawada, Michal

2013-01-01

218

ABSOLUTE BUNCH LENGTH MEASUREMENTS AT THE ALS BY INCOHERENT SYNCHROTRON RADIATION FLUCTUATION ANALYSIS  

International Nuclear Information System (INIS)

By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and tested a simple scheme based on this principle that allows for the absolute measurement of the bunch length. A description of the method and the experimental results are presented

219

Measurement of the absolute branching fractions for Do decays into K-?+,K-?+?+?-, anti Kanti o?+?-  

International Nuclear Information System (INIS)

Using the ARGUS detector at the e+e- storage ring DORIS II we have measured the absolute branching ratios of the D-o meson, Br(D0?K-?+)=(3.41±0.12±0.28)%, Br(D0?K-?+?+?-)=(6.80±0.27±0.57)%, and Br(D0? anti K0?+?-)=(5.03±0.39±0.49)%. (orig.)

220

FFTF (FAST FLUX TEST FACILITY) REACTOR CHARACTERIZATION PROGRAM ABSOLUTE FISSION RATE MEASUREMENTS  

Energy Technology Data Exchange (ETDEWEB)

Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

FULLER JL; GILLIAM DM; GRUNDL JA; RAWLINS JA; DAUGHTRY JW

1981-05-01

221

FFTF (Fast Flux Test Facility) Reactor Characterization Program: Absolute Fission-rate Measurements  

Energy Technology Data Exchange (ETDEWEB)

Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

Fuller, J.L.; Gilliam, D.M.; Grundl, J.A.; Rawlins, J.A.; Daughtry, J.W.

1981-05-01

222

Comment on "Measurement of the speed-of-light perturbation of free-fall absolute gravimeters"  

CERN Document Server

The paper (Rothleitner et al. 2014 Metrologia 51, L9) reports on the measurement of the speed-of-light perturbation in absolute gravimeters. The conclusion that the perturbation reaches only 2/3 of the commonly accepted value violates the fundamental limitation on the maximum speed of information transfer. The conclusion was deluded by unaccounted parasitic perturbations, some of which are obvious from the report.

Nagornyi, V D

2014-01-01

223

High-accuracy absolute distance measurement using frequency comb referenced multiwavelength source  

International Nuclear Information System (INIS)

We propose a new approach to multiple-wavelength interferometry, targeted to high bandwidth absolute distance measurement, with nanometer accuracy over long distances. Two cw lasers are stabilized over a wide range of frequency intervals defined by an optical frequency comb, thus offering an unprecedented large choice of synthetic wavelengths. By applying a superheterodyne detection technique, we demonstrated experimentally an accuracy of 8 nm over 800 mm for target velocities up to 50 mm/s

224

High-accuracy absolute distance measurement using frequency comb referenced multiwavelength source.  

Science.gov (United States)

We propose a new approach to multiple-wavelength interferometry, targeted to high bandwidth absolute distance measurement, with nanometer accuracy over long distances. Two cw lasers are stabilized over a wide range of frequency intervals defined by an optical frequency comb, thus offering an unprecedented large choice of synthetic wavelengths. By applying a superheterodyne detection technique, we demonstrated experimentally an accuracy of 8 nm over 800 mm for target velocities up to 50 mm/s. PMID:18470268

Salvadé, Yves; Schuhler, Nicolas; Lévêque, Samuel; Le Floch, Sébastien

2008-05-10

225

Absolute measurement of enhanced fluctuations in assemblies of biomolecules by ultrasonic techniques.  

OpenAIRE

By expressing the fluctuation-dissipation theorem explicitly, equations are obtained for the ultrasonic relaxation amplitudes that contain one single molecular parameter, i.e., the fluctuation, or the sum of fluctuations. The absolute measurement of this parameter is therefore possible. The equations apply to a two-state system, to a multistate system and to a linear Ising chain as well. In an aqueous medium, where molar volume changes are important, the ultrasonic relaxation amplitudes are p...

Cerf, R.

1985-01-01

226

Measurement of the speed-of-light perturbation of free-fall absolute gravimeters  

OpenAIRE

We report on a direct measurement of the relativistic Doppler shift with a commercial free-fall absolute gravimeter of the type FG5X. The observed Doppler shift, which is commonly called speed-of-light perturbation, can be well described by the relativistic Doppler formula, where the constant object velocity is replaced by a time-dependent velocity with constant acceleration. The observed speed-of-light perturbation stands in contrast to other publications, which predict a higher frequency sh...

Rothleitner, Christian; Niebauer, Tim; Francis, Olivier

2014-01-01

227

Geometry of expanding absolutely continuous invariant measures and the liftability problem  

International Nuclear Information System (INIS)

We consider a quite broad class of maps on compact manifolds of arbitrary dimension possibly admitting critical points, discontinuities and singularities. Under some mild nondegeneracy assumptions we show that f admits an induced Gibbs-Markov map with integrable inducing times if and only if it has an ergodic invariant probability measure which is absolutely continuous with respect to the Riemannian volume and has all Lyapunov exponents positive. (author)

228

Measurements of radioactive dusts in high altitude air  

International Nuclear Information System (INIS)

The radioactivities of the airborne dusts were measured in samples collected by an aircraft of the Japan Air Self-Defense Force in high altitude during the period between April 1998 and March 1999. The data of the gross beta activities, gamma nuclide determination and radiochemical analysis show that there is no appreciable difference from the activity levels of the year before and seasonal variations are becoming not so clear, that shows the radioactivities in high altitude is stable in low level. (author)

229

Natural radioactivity measurements at the proposed nuclear power plant site  

International Nuclear Information System (INIS)

Natural radioactivity measurement in the Philippines aims to establish baseline radioactivity levels in the environment of items essential to man. In this article, results of the environmental surveillance conducted in Bagac, Bataan from 1973 to 1974 are presented. Analyses were made on air parti-culates, sea and fresh water, grass, and soil samples for gross beta-gamma activities. Results obtained showed activity levels below the maximum permissible concentration recommended by the International Committee on Radiation Protection (ICRP)

230

A new absolute reference for atmospheric longwave irradiance measurements with traceability to SI units  

Science.gov (United States)

Two independently designed and calibrated absolute radiometers measuring downwelling longwave irradiance were compared during two field campaigns in February and October 2013 at Physikalisch Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC). One absolute cavity pyrgeometer (ACP) developed by NREL and up to four Integrating Sphere Infrared Radiometers (IRIS) developed by PMOD/WRC took part in these intercomparisons. The internal consistency of the IRIS radiometers and the agreement with the ACP were within ±1 W m-2, providing traceability of atmospheric longwave irradiance to the international system of units with unprecedented accuracy. Measurements performed during the two field campaigns and over the past 4 years have shown that the World Infrared Standard Group (WISG) of pyrgeometers is underestimating clear-sky atmospheric longwave irradiance by 2 to 6 W m-2, depending on the amount of integrated water vapor (IWV). This behavior is an instrument-dependent feature and requires an individual sensitivity calibration of each pyrgeometer with respect to an absolute reference such as IRIS or ACP. For IWV larger than 10 mm, an average sensitivity correction of +6.5% should be applied to the WISG in order to be consistent with the longwave reference represented by the ACP and IRIS radiometers. A concerted effort at international level will need to be implemented in order to correct measurements of atmospheric downwelling longwave irradiance traceable to the WISG.

Gröbner, J.; Reda, I.; Wacker, S.; Nyeki, S.; Behrens, K.; Gorman, J.

2014-06-01

231

Relative Gravity Measurement Campaign during the 8th International Comparison of Absolute Gravimeters (2009)  

Science.gov (United States)

The 8th International Comparison of Absolute Gravimeters (ICAG-2009) and the associated Relative Gravity Campaign (RGC2009) took place at the Bureau International des Poids et Mesures (BIPM) between July and October 2009. Altogether 24 institutes with 22 absolute gravimeters and 9 relative gravimeters participated in the ICAG/RGC campaign. Accurate absolute and relative gravity measurements as well as precision levelling measurements were performed on the micro-gravity 3D-grid at the BIPM. The 2009 comparison was the first to be organized as a Comité International des Poids et Mesures (CIPM) metrological Key Comparison under the CIPM MRA (Mutual Recognition Arrangement), which means that the result will be officially recognized by the governmental organizations responsible. As a consequence, the relative gravimeters employed were carefully selected and the measurement schedules were rigorously enforced compared with earlier campaigns. Thus the quality of the RGC2009 and the determination of the BIPM local gravity network were improved. After 30 years and eight successive ICAGs, the BIPM has decided to transfer its role to the national metrological institutes, although the CIPM will continue to organize the key comparison as ICAGs. The background to the RGC2009, and the organization, data processing and final results of the gravity and vertical gravity gradients, are presented in this paper. This report is more detailed than previous final reports of the RGCs.

Jiang, Z.; Pálinkáš, V.; Francis, O.; Jousset, P.; Mäkinen, J.; Merlet, S.; Becker, M.; Coulomb, A.; Kessler-Schulz, K. U.; Schulz, H. R.; Rothleitner, Ch; Tisserand, L.; Lequin, D.

2012-02-01

232

Measurement of statistical evidence on an absolute scale following thermodynamic principles.  

Science.gov (United States)

Statistical analysis is used throughout biomedical research and elsewhere to assess strength of evidence. We have previously argued that typical outcome statistics (including p values and maximum likelihood ratios) have poor measure-theoretic properties: they can erroneously indicate decreasing evidence as data supporting an hypothesis accumulate; and they are not amenable to calibration, necessary for meaningful comparison of evidence across different study designs, data types, and levels of analysis. We have also previously proposed that thermodynamic theory, which allowed for the first time derivation of an absolute measurement scale for temperature (T), could be used to derive an absolute scale for evidence (E). Here we present a novel thermodynamically based framework in which measurement of E on an absolute scale, for which "one degree" always means the same thing, becomes possible for the first time. The new framework invites us to think about statistical analyses in terms of the flow of (evidential) information, placing this work in the context of a growing literature on connections among physics, information theory, and statistics. PMID:23463577

Vieland, V J; Das, J; Hodge, S E; Seok, S-C

2013-09-01

233

LHCb: A novel method for an absolute luminosity measurement at LHCb using beam-gas imaging  

CERN Multimedia

A novel technique to measure the absolute luminosity at the Large Hadron Collider (LHC) using beam-gas interactions has been successfully used in the LHCb experiment. A gas injection device (SMOG) has been installed in the LHCb experiment to increase the pressure around the interaction point during dedicated fills. The Beam Gas Imaging method (BGI) has now the potential to surpass the accuracy of the commonly used van der Meer scan method (VDM). This poster presents the principles of the Beam Gas Imaging method used to measure the beam overlap integral. Furthermore the gas injection increased the accuracy measurement of the so-called ghost charges and also intensities per bunch.

Barschel, C

2013-01-01

234

Measurement of the Absolute np Scattering Differential Cross Section at 194 MeV  

CERN Document Server

We describe a double-scattering experiment with a novel tagged neutron beam to measure differential cross sections for np back-scattering to better than 2% absolute precision. The measurement focuses on angles and energies where the cross section magnitude and angle-dependence constrain the charged pion-nucleon coupling constant, but existing data show serious discrepancies among themselves and with energy-dependent partial wave analyses (PWA). The present results are in good accord with the PWA, but deviate systematically from other recent measurements.

Sarsour, M; Planinic, M; Vigdor, S E; Allgower, C; Bergenwall, B; Blomgren, J; Hossbach, T; Jacobs, W W; Johansson, C; Klug, J; Klyachko, A V; Nadel-Turonski, P; Nilsson, L; Olsson, N; Pomp, S; Rapaport, J; Rinckel, T; Stephenson, E J; Tippawan, U; Wissink, S W; Zhou, Y

2004-01-01

235

Measurements with radioactive beams at ATLAS.  

Energy Technology Data Exchange (ETDEWEB)

Reactions of interest to nuclear astrophysics have been studied with radioactive beams at the ATLAS accelerator. Using a modified ISOL technique, beams of {sup 18}F (T{sub 1/2} = 110 min) and {sup 56}Ni (T{sub 1/2} = 6.1d) were produced and the reactions {sup 18}F(p,{alpha}){sup 15}O, {sup 18}F(p,{gamma}){sup 19}Ne, and {sup 56}Ni(d,p){sup 57}Ni have been investigated. The results indicate that the {sup 18}F(p,{gamma}) route is a small contributor to the breakout from the hot CNO cycle into the rp process, while the {sup 56}Ni(p,{gamma}){sup 57}Cu rate is about ten times larger than previously assumed.

Rehm, K. E.

1998-08-06

236

An interim report of the Subcommittee on Radioactive Waste Countermeasures: measures for radioactive waste treatment and disposal  

International Nuclear Information System (INIS)

The Subcommittee on Radioactive Waste Countermeasures has studied on the measures for land disposal of low-level radioactive wastes and ultra-low-level radioactive wastes and the measures for treatment and disposal of high-level radioactive wastes and transuranium wastes. The results of studies so far are presented as an interim report. In disposal of low-level radioactive wastes, the land disposal is being required increasingly. The measures according to the levels of radioactivity are necessary. For the ultra-low-level radioactive wastes, their occurrence in large quantities is expected along with reactor decommissioning. In disposal of the high-level radioactive wastes, the present status is a transition toward the practical stages. Transuranium wastes should increase in their arising in the future. (Mori, K.)

237

Measurement of total body radioactivity in man  

International Nuclear Information System (INIS)

Techniques for the determination of whole-body radioactivity in man using uncollimated NaI(Tl) detectors have been studied. Geometrical effects and photon attenuation effects due to the different shapes of humans as well as due to varying in-vivo radioactivity distributions have been evaluated particularly for scanning-bed geometries and the chair geometry. Theoretically it is shown that the attenuation effects are generally dominating, for full-energy-peak pulse-range methods. For the application in radiation protection a cheap and simple chair-geometry unit has been constructed and used at various places distantly from the home-laboratory, for studies of body activity of Cs-137 in northern Sweden. High body activities were found particularly in reindeer-breeding Lapps. The elimination rate of Cs-137 in man was studied in the stationary whole-body counter in Lund as well as with the field-system. For the study of the performances at low and high photon energies clinical applications of methods for gastro-intestinal absorption of vitamin B12 (Co-57; 122 keV) and total body potassium determination (K-40; 1.46 MeV, K-42; 1.52 MeV) have been evaluated. Theoretical and experimental results as well as experiences of applications in radiation protection and medicine show that the scanning-bed geometry effectively evens out redistributional effects. For optimum results, however, scatter-energy pulse-ranges rather than full-energy-peak ranges should be used. (Auth.)

238

Radiation Protection Research: Low-level Radioactivity Measurements  

Energy Technology Data Exchange (ETDEWEB)

The objectives of the research performed in the area of low-level radioactivity measurements are (1) to maintain and develop techniques for the measurement of low-level environmental and biological samples, (2) to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters, alpha spectrometry), (3) to support and advice the nuclear and non-nuclear industry in matters concerning radioactive contamination and/or low-level radioactivity measurements; (4) to maintain the quality assurance system according to the EN45001 standard; and (5) to assess the internal dose from occupational intakes of radionuclides of workers of the nuclear industry. Progress and achievements in these areas in 1999 are reported. Particular emphasis is SCK-CEN's contribution to the EULEP-EURADOS Action Group on 'Derivation of parameter values for application in the new model of the human respiratory tract for occupational exposure'.

Hurtgen, C

2000-07-01

239

Scanning Laser Polarimetry for Measurement of Retinal Nerve Fiber Layer in Absolute, Advanced and Early Glaucoma  

Directory of Open Access Journals (Sweden)

Full Text Available Background: To detect differences in retinal nerve fiber layer (RNFL measurements inabsolute, advanced and early glaucoma with scanning laser polarimetry (TheNerve Fiber Analyzer GDx, and to assess the usefulness and limitations ofthis technique for longitudinal follow-up of glaucoma patients.Methods: This is a prospective, cross-sectional study. Twenty-one eyes of 21 patientswith absolute glaucoma, twenty-six eyes of 26 patients with advanced glaucomaand twenty-four eyes of 24 patients with early glaucoma were imagedusing scanning laser polarimetry. The twelve standard GDx measurementparameters were compared using ANOVA (analysis of variance and theTukey test.Results: No significant differences were demonstrated for any of the twelve GDxmeasurement parameters between absolute and advanced glaucoma cases.There were significant differences for some GDx parameters, including theGDx number (p < 0.0001 superior ratio (p < 0.0001, inferior ratio (p <0.0001, superior/nasal ratio (p < 0.0001, maximum modulation (p <0.0001, ellipse modulation (p < 0.0001 and inferior average (p = 0.001between early and advanced glaucoma, and, between early and absoluteglaucoma. Significant differences were demonstrated for the superior average(p = 0.01 parameter between early and absolute glaucoma, but notbetween early and advanced glaucoma.Conclusions: For follow-up of glaucoma progression, RNFL measurements using scanninglaser polarimetry are more useful in the early stage than in the advancedstage.

Jen-Chia Tsai

2006-04-01

240

Absolute pulse energy measurements of soft x-rays at the Linac Coherent Light Source.  

Science.gov (United States)

This paper reports novel measurements of x-ray optical radiation on an absolute scale from the intense and ultra-short radiation generated in the soft x-ray regime of a free electron laser. We give a brief description of the detection principle for radiation measurements which was specifically adapted for this photon energy range. We present data characterizing the soft x-ray instrument at the Linac Coherent Light Source (LCLS) with respect to the radiant power output and transmission by using an absolute detector temporarily placed at the downstream end of the instrument. This provides an estimation of the reflectivity of all x-ray optical elements in the beamline and provides the absolute photon number per bandwidth per pulse. This parameter is important for many experiments that need to understand the trade-offs between high energy resolution and high flux, such as experiments focused on studying materials via resonant processes. Furthermore, the results are compared with the LCLS diagnostic gas detectors to test the limits of linearity, and observations are reported on radiation contamination from spontaneous undulator radiation and higher harmonic content. PMID:25321502

Tiedtke, K; Sorokin, A A; Jastrow, U; Jurani?, P; Kreis, S; Gerken, N; Richter, M; Arp, U; Feng, Y; Nordlund, D; Soufli, R; Fernández-Perea, M; Juha, L; Heimann, P; Nagler, B; Lee, H J; Mack, S; Cammarata, M; Krupin, O; Messerschmidt, M; Holmes, M; Rowen, M; Schlotter, W; Moeller, S; Turner, J J

2014-09-01

241

Absolute internal conversion coefficient measurements of some transitions in the decay of 228Ac?228Th  

International Nuclear Information System (INIS)

The absolute internal conversion coefficients of the following transitions have been measured in the decay of 228Ac : ?sub(K) values for the 204.1-, 270.3-, 328.0-, 338.0-, 409.4 and 463.0- keV transitions; L subshell ? values for the 57.76-, 99.45-, 129.1-, and 184.6- keV transitions. The gamma spectrum was observed with a 20 c.c. Ge(Li) detector and the conversion electron spectra were observed using a ??2 double focussing ?-spectrometer with a resolution of 0.1% or better. The theoretical value of ?sub(LIII) for the 129.1 keV transition was used for reference. In a few cases where earlier results are available, the present results are in agreement with them. For the remaining transitions, absolute conversion coefficients are reported for the first time. (auth.)

242

Measurements of radioactive dusts in high altitude air  

International Nuclear Information System (INIS)

The radioactivities of the airborne dusts were measured in samples collected by aircrafts of the Japan Air Self-Defense Force in high altitude during the period between April 2000 and March 2001. From June 2000 the newly designed filters composed of electret filter and fibrous activated carbon filter were used to collect air suspended dust and radioactive gas at the same time. The data of the gross beta activities, gamma nuclide determination and radiochemical analysis show that there is no appreciable difference from the activity levels of the year before and seasonal variations are becoming not so clear, that shows the radioactivities in high altitude is stable in a low level. Radioactive gas (gaseous radioiodine) was not detected. (author)

243

Absolute silicon molar mass measurements, the Avogadro constant and the redefinition of the kilogram  

Science.gov (United States)

The results of an absolute silicon molar mass determination of two independent sets of samples from the highly 28Si-enriched crystal (AVO28) produced by the International Avogadro Coordination are presented and compared with results published by the Physikalisch-Technische Bundesanstalt (PTB, Germany), the National Research Council (NRC, Canada) and the National Metrology Institute of Japan (NMIJ, Japan). This study developed and describes significant changes to the published protocols for producing absolute silicon isotope ratios. The measurements were made at very high resolution on a multi-collector inductively coupled plasma mass spectrometer using tetramethylammonium hydroxide (TMAH) to dissolve and dilute all samples. The various changes in the measurement protocol and the use of TMAH resulted in significant improvements to the silicon isotope ratio precision over previously reported measurements and in particular, the robustness of the 29Si/30Si ratio of the AVO28 material. These new results suggest that a limited isotopic variability is present in the AVO28 material. The presence of this variability is at present singular and therefore its significance is not well understood. Fortunately, its magnitude is small enough so as to have an insignificant effect on the overall uncertainty of an Avogadro constant derived from the average molar mass of all four AVO28 silicon samples measured in this study. The NIST results confirm the AVO28 molar mass values reported by PTB and NMIJ and confirm that the virtual element-isotope dilution mass spectrometry approach to calibrated absolute isotope ratio measurements developed by PTB is capable of very high precision as well as accuracy. The Avogadro constant NA and derived Planck constant h based on these measurements, together with their associated standard uncertainties, are 6.02214076(19) × 1023 mol-1 and 6.62607017(21) × 10-34 Js, respectively.

Vocke, R. D., Jr.; Rabb, S. A.; Turk, G. C.

2014-10-01

244

Heat generation amount measuring device for radioactive waste containing vessel  

International Nuclear Information System (INIS)

The present invention provides a device for measuring heat fluxes on the entire surface of a radioactive waste containing vessel in a short period of time and determining the entire heat generation amount. If a rotational driving means is operated in a state where the radioactive waste containing vessel is loaded thereon, positions of contact of heat flux meters arranged in a row are changed in a circumferential direction, the heat fluxes on the entire surface of radioactive waste containing vessel are measured and the entire heat generation amount of the waste containing vessel is calculated. Since a plurality of the heat flux meters are positioned separately, elastic contact with the radioactive waste containing vessel is kept relative to the unevenness on the outer surface of the radioactive waste containing vessel. If the heat flux meters are moved integrally while being loaded on a moving means, contact or noncontact state of the heat flux meters relative to the radioactive waste containing vessel is set rapidly. (I.S.)

245

Assembly for measuring concentrations of radioactivity  

International Nuclear Information System (INIS)

The assembly for measuring the activity of noble gases and aerosols uses a ?-measuring equipment. A compressor conveys the substances into the measuring space enclosed by a Pb or W shielding. Within the same shielding there are arranged a second measuring chamber plus detector for background compensation and a third measuring chamber plus detector for measurement of the aerosol concentration, e.g. for determination of the dose caused by incorporation. For this purpose there is provided for an aerosol filter. The compressor can transport the gases or aerosols through all three chambers if the aerosol filter is connected between the first and second measuring chamber and the compressor is connected between the first measuring chamber and the aerosol filter. (DG)

246

Measurement of the speed-of-light perturbation of free-fall absolute gravimeters  

Science.gov (United States)

We report on a direct measurement of the relativistic Doppler shift with a commercial free-fall absolute gravimeter of the type FG5X. The observed Doppler shift, which is commonly called speed-of-light perturbation, can be well described by the relativistic Doppler formula, where the constant object velocity is replaced by a time-dependent velocity with constant acceleration. The observed speed-of-light perturbation stands in contrast to other publications, which predict a higher frequency shift. It has been measured with a relative uncertainty of 1.1 × 10-3.

Rothleitner, Ch; Niebauer, T. M.; Francis, O.

2014-06-01

247

Absolute Position of Targets Measured Through a Chamber Window Using Lidar Metrology Systems  

Science.gov (United States)

Lidar is a useful tool for taking metrology measurements without the need for physical contact with the parts under test. Lidar instruments are aimed at a target using azimuth and elevation stages, then focus a beam of coherent, frequency modulated laser energy onto the target, such as the surface of a mechanical structure. Energy from the reflected beam is mixed with an optical reference signal that travels in a fiber path internal to the instrument, and the range to the target is calculated based on the difference in the frequency of the returned and reference signals. In cases when the parts are in extreme environments, additional steps need to be taken to separate the operator and lidar from that environment. A model has been developed that accurately reduces the lidar data to an absolute position and accounts for the three media in the testbed air, fused silica, and vacuum but the approach can be adapted for any environment or material. The accuracy of laser metrology measurements depends upon knowing the parameters of the media through which the measurement beam travels. Under normal conditions, this means knowledge of the temperature, pressure, and humidity of the air in the measurement volume. In the past, chamber windows have been used to separate the measuring device from the extreme environment within the chamber and still permit optical measurement, but, so far, only relative changes have been diagnosed. The ability to make accurate measurements through a window presents a challenge as there are a number of factors to consider. In the case of the lidar, the window will increase the time-of-flight of the laser beam causing a ranging error, and refract the direction of the beam causing angular positioning errors. In addition, differences in pressure, temperature, and humidity on each side of the window will cause slight atmospheric index changes and induce deformation and a refractive index gradient within the window. Also, since the window is a dispersive media, the effect of both phase and group indices have to be considered. Taking all these factors into account, a method was developed to measure targets through multiple regions of different materials and produce results that are absolute measurements of target position in three-dimensional space, rather than simply relative position. The environment in which the lidar measurements are taken must be broken down into separate regions of interest and each region solved for separately. In this case, there were three regions of interest: air, fused silica, and vacuum. The angular position of the target inside the chamber is solved using only phase index and phase velocity, while the ranging effects due to travel from air to glass to vacuum/air are solved with group index and group velocity. When all parameters are solved simultaneously, an absolute knowledge of the position of each target within an environmental chamber can be derived. Novel features of this innovation include measuring absolute position of targets through multiple dispersive and non-dispersive media, deconstruction of lidar raw data from a commercial off-the-shelf unit into reworkable parameters, and use of group velocities to reduce range data. Measurement of structures within a vacuum chamber or other harsh environment, such as a furnace, may now be measured as easily as if they were in an ambient laboratory. This analysis permits transformation of the raw data into absolute spatial units (e.g., mm). This technique has also been extended to laser tracker, theodolite, and cathetometer measurements through refractive media.

Kubalak, David; Hadjimichael, Theodore; Ohl, Raymond; Slotwinski, Anthony; Telfer, Randal; Hayden, Joseph

2012-01-01

248

A new Ultra Precision Interferometer for absolute length measurements down to cryogenic temperatures  

International Nuclear Information System (INIS)

A new Ultra Precision Interferometer (UPI) was built at Physikalisch-Technische Bundesanstalt. As its precursor, the precision interferometer, it was designed for highly precise absolute length measurements of prismatic bodies, e.g. gauge blocks, under well-defined temperature conditions and pressure, making use of phase stepping imaging interferometry. The UPI enables a number of enhanced features, e.g. it is designed for a much better lateral resolution and better temperature stability. In addition to the original concept, the UPI is equipped with an external measurement pathway (EMP) in which a prismatic body can be placed alternatively. The temperature of the EMP can be controlled in a much wider range compared to the temperature of the interferometer's main chamber. An appropriate cryostat system, a precision temperature measurement system and improved imaging interferometry were established to permit absolute length measurements down to cryogenic temperature, demonstrated for the first time ever. Results of such measurements are important for studying thermal expansion of materials from room temperature towards less than 10 K. (paper)

249

Dual-band MWIR/LWIR radiometer for absolute temperature measurements  

Science.gov (United States)

A Dual-band Radiometer (DBR) has been developed to accurately measure temperature at long ranges. Key to the DBR is a dual-band, quantum well infrared photodetector (QWIP) focal plane array (FPA) that integrates within each pixel both mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) spectral sensitivity. A vertically-integrated, two-color FPA eliminates with inter-band optical distortions, temperature-induced alignment errors, and improves radiometric measurement accuracy. The DBR system is sensitive to human targets, yet minimally sensitive to atmospheric conditions, enabling accuracy over the widest possible range of global conditions by using Two-color Imaging Radiometry (TCIR) to establish a target's absolute temperature within +/- 1°C. The benefits of TCIR for greybody measurements are absolute atmospheric transmission values are not required and uncorrelated shifts in the spectral band transmission cause minimal error. The system is packaged with an eye-safe laser rangefinder, GPS, and weather station suite, which provides real-time atmospheric measurements. These measurements are input to the USAF MOSART predictive atmospheric codes, which are used for real-time field calibration of the data. The magnification necessary to resolve facial features from 200 m to 750 m range requires a custom designed 6" diameter, f/7 telescope with temperature-stable optical alignment over a wide range of operational temperatures.

Williams, George M.; Barter, Archie

2006-04-01

250

Absolute reliability of isokinetic knee flexion and extension measurements adopting a prone position.  

Science.gov (United States)

The main purpose of this study was to determine the absolute and relative reliability of isokinetic peak torque (PT), angle of peak torque (APT), average power (PW) and total work (TW) for knee flexion and extension during concentric and eccentric actions measured in a prone position at 60, 180 and 240° s(-1). A total of 50 recreational athletes completed the study. PT, APT, PW and TW for concentric and eccentric knee extension and flexion were recorded at three different angular velocities (60, 180 and 240° s(-1)) on three different occasions with a 72- to 96-h rest interval between consecutive testing sessions. Absolute reliability was examined through typical percentage error (CV(TE)), percentage change in the mean (ChM) and relative reliability with intraclass correlations (ICC(3,1)). For both the knee extensor and flexor muscle groups, all strength data (except APT during knee flexion movements) demonstrated moderate absolute reliability (ChM 0·70; and CV(TE) values reported for PT (8-20%), APT (8-18%) (only during knee extension movements), PW (14-20%) and TW (12-28%) may be acceptable to detect the large changes usually observed after rehabilitation programmes, but not acceptable to examine the effect of preventative training programmes in healthy individuals. PMID:23216765

Ayala, F; De Ste Croix, M; Sainz de Baranda, P; Santonja, F

2013-01-01

251

Absolute photoionization cross-section measurements of the Kr I isoelectronic sequence  

Science.gov (United States)

Photoionization spectra have been recorded in the 4s , 4p , and 3d resonance regions for the Kr I isoelectronic sequence using both the dual laser produced plasma (DLP) technique (at DCU) to produce photoabsorption spectra, and the merged ion beam and synchrotron radiation technique (at ASTRID) to measure absolute photoionization cross sections. Profile parameters are compared for the 4s-np resonances of Rb+ and Sr2+ . Many 4p?ns , md transitions are identified with the aid of Hartree-Fock calculations, and consistent quantum defects are observed for the various ns and md Rydberg series. Absolute single and double photoionization cross sections recorded in the 3d region for Rb+ and Sr2+ ions show preferential decay via double photoionization. This is only the second report to our knowledge where both the DLP technique and the merged-beam technique have been used simultaneously to record photoionization spectra, and the advantages of both techniques (i.e., better resolution in the case of DLP and values for absolute photoionization cross sections in the case of the merged-beam technique) are highlighted.

Kilbane, D.; Folkmann, F.; Bizau, J.-M.; Banahan, C.; Scully, S.; Kjeldsen, H.; van Kampen, P.; Mansfield, M. W. D.; Costello, J. T.; West, J. B.

2007-03-01

252

Measurement methodology of natural radioactivity in the thermal establishments  

International Nuclear Information System (INIS)

The thermal baths have been identified as an activity susceptible to expose to ionizing radiations the workers through the natural sources of radon and radon 220. The new regulation obliges these facilities to realize radioactivity measurements. The principal ways of exposure are radon and its daughters inhalation,, exposure to gamma radiation, ingestion of radioelements in thermal waters. I.R.S.N. proposes two methods of measurements of the natural radioactivity in application to the regulation relative to the protection of persons and workers. Some principles to reduce exposure to radon are reminded. (N.C.)

253

Absolute radiant power measurement of the X-ray free-electron laser at SACLA  

International Nuclear Information System (INIS)

The Japanese hard X-ray free-electron laser (XFEL), SACLA (SPring-8 Angstrom Compact free-electron LAser), reached laser amplification at 10 keV photon energy in June 2011. SACLA can provide XFELs with its wavelength of shorter than 0.1 nm. Since the radiant power is a fundamental parameter of the XFEL beam which strongly influences nonlinear effects, its measurement in absolute terms is of significant importance. In the present study, the absolute radiant power of the XFEL was measured using a cryogenic radiometer at the BL3 in SACLA. The radiant power as a function of a silicon attenuator thickness was also measured to estimate the contribution of the higher harmonics. The radiant power in the range between 8 ?W and 1005 ?W was measured in the photon energies of 4.4 keV, 5.8 keV, 9.6 keV, 13.6 keV and 16.8 keV. The contribution of the higher harmonics is negligible except for the photon energy of 4.4 keV. The third harmonics component in the photon energy of 4.4 keV is about 1 %.

254

Measurements of radioactive dust in high altitude air  

International Nuclear Information System (INIS)

The radioactivity in samples of airborne dust was measured. The samples had been collected at high altitude by the Japan Air Self-Defense Force. The data were obtained for the gross beta activity, gamma nuclide determination and radiochemical analysis. It was shown that there was no appreciable difference between the activity levels obtained in this time and in the year before. Seasonal variations were not very pronounced. It was found that the radioactivity at high altitude had been stable at a low level. Radioactive gases (gaseous radioiodine and xenon gas) were not detected. This report does not include the result on radionuclide measurements that Technical Research and Development Institute executed for examining the nuclear emergency situation at Fukushima Daiichi and Daini nuclear power plants after Tohoku Region Pacific Ocean Earthquake on March 11, 2011. (author)

255

Croatian-Hungarian cooperation on the Danube river radioactivity measurements  

International Nuclear Information System (INIS)

Danube river radioactivity measurements on the border profile Mohac-Batina have been performed since the beginning of 1978 with varying frequency of sampling. Thus, in the period before nuclear power plant Paks started to work joint croatian-hungarian sampling at the border profile was taking place four times a year; the obtained results of measured radioactivity levels were used to assess radioactivity background data. From the start of nuclear power plant Paks running until Chernobyl reactor accident (April 1986) sampling was performed six times a year. After the Chernobyl accident, samples have been taken every month. Since decreased Chernobyl reactor accident influence was estimated until present samples have been taken six times a year. On the Danube river border profile the concentration activity of gamma radionuclides has been determined in water samples (filtered water and suspended matter), and in fish, sediment and Danube river algae samples. (authors)

256

Improvement of a new portable monitor for measuring radioactivity levels  

International Nuclear Information System (INIS)

Using a silicon photodiode as a sensor, the author has developed a new portable monitor for clinical use to measure irradiation from an inner organ through the body surface after the administration of radiopharmaceutical agent. The monitor can record the time course of radioactivity and can be assessed in the outpatient clinic. The total weight of this monitor is 660 g: the detector 70 g, the recorder 295 g, and the battery 295 g. In the present study, the monitor was utilized to measure and record the radioactivity in the bladder content of a patient who had been given Tc-99m methylene-diphosphonate for bone scintigraphy. The detector probe was placed on the abdomen over the bladder and fixed with adhesive tape. The recorder and battery were carried in a small backpack. The correlation between the radioactivity level in the urinary excretion and the count rate estimated by the monitor on the wall of urinary bladder was investigated. The average time to the first urinary excretion was made approximately 2 hr after the administration of radiopharmaceutical agent. The radioactivity count from the bladder reached the maximum level after approximately 2-3 hr, and subsequently decreased. The radioactivity in urine when excreted at 1 hr after administration was at 85% of that when excreted at 2 hr. In conclusion, the absorbed dosage in the bladder could be significantly reduced when the patients urinate at 1 hr after the administration of radiopharmaceutical agent. The newlion of radiopharmaceutical agent. The newly developed portable monitor was adaptable to determine the radioactivity of inner organs directly from the outside of the body surface, and is effective in clinical management for excretion of clinical radioactive agents. (author)

257

Measurement of the absolute number of electrons in the KUTI prototype storage ring  

International Nuclear Information System (INIS)

Experimental results are reported on determining the electron energy from the spectrum of the synchrotron radiation (SR). The SR spectrum was measured over a single compression cycle, as well as over many cycles, and the resulting energies were used to deduce the absolute number of electrons in the ring. Three types of photoreceivers measured the SR intensity: 1) a germanium photodiode at wavelength lambda = 1.6 ?m; 2) a cooled photoresistor at lambda = 2.4 ?m; 3) a photomultiplier with a set of narrow-band filters at wavelengths lambda = 0.63 and 0.41 ?m. The dependence of the angular distribution of the SR on the number of electrons must be allowed for in measurements at visible wavelengths. The maximum number of electrons in the ring was found to be 8 x 1012. Measurements carried out using different photoreceivers were in agreement to within 20%

258

Absolute Position Measurement in a Gas Time Projection Chamber via Transverse Diffusion of Drift Charge  

CERN Document Server

Time Projection Chambers (TPCs) with charge readout via micro pattern gaseous detectors can provide detailed measurements of charge density distributions. We here report on measurements of alpha particle tracks, using a TPC where the drift charge is amplified with Gas Electron Multipliers and detected with a pixel ASIC. We find that by measuring the 3-D topology of drift charge and fitting for its transverse diffusion, we obtain the absolute position of tracks in the drift direction. For example, we obtain a precision of 1~cm for 1~cm-long alpha track segments. To our knowledge this is the first demonstration of such a measurement in a gas TPC. This technique has several attractive features: it does not require knowledge of the initial specific ionization, is robust against bias from diffuse charge below detection threshold, and is also robust against high charge densities that saturate the detector response.

Lewis, P M; Hedges, M T; Jaegle, I; Seong, I S; Thorpe, T N

2014-01-01

259

Absolute distance measurement with extension of nonambiguity range using the frequency comb of a femtosecond laser  

Science.gov (United States)

We revisit the method of synthetic wavelength interferometry (SWI) for absolute measurement of long distances using the radio-frequency harmonics of the pulse repetition rate of a mode-locked femtosecond laser. Our intention here is to extend the nonambiguity range (NAR) of the SWI method using a coarse virtual wavelength synthesized by shifting the pulse repetition rate. The proposed concept of NAR extension is experimentally verified by measuring a ˜13-m distance with repeatability of 9.5 ?m (root-mean-square). The measurement precision is estimated to be 31.2 ?m in comparison with an incremental He-Ne laser interferometer. This extended SWI method is found to be well suited for long-distance measurements demanded in the fields of large-scale precision engineering, geodetic survey, and future space missions.

Jang, Yoon-Soo; Lee, Keunwoo; Han, Seongheum; Lee, Joohyung; Kim, Young-Jin; Kim, Seung-Woo

2014-12-01

260

Radioactivity measurements of the HMI after the Chernobyl reactor accident  

International Nuclear Information System (INIS)

The report explains the methods applied and the data measured by the HMI campaign. The material is presented so as to be of interest also to readers who in general are not concerned with aspects of radiation protection. The data measured refer to the local dose rate and to radioactivity in the environment (air, rain, surface waters, soil, food, mother's milk. Also, results of measurements of samples from Eastern Europe are given. (orig./HP)

261

Direct, Absolute, and In Situ Measurement of Fast Electron Transport via Cherenkov Emission  

International Nuclear Information System (INIS)

We present direct measurements of the absolute energy distribution of relativistic electrons generated in intense, femtosecond laser interaction with a solid. Cherenkov emission radiated by these electrons in a novel prism target is spectrally dispersed to obtain yield and energy distribution of electrons simultaneously. A crucial advance is the observation of high density electron current as predicted by particle simulations and its transport as it happens inside the target. In addition, the strong sheath potential present at the rear side of the target is inferred from a comparison of the electron spectra derived from Cherenkov light observation with that from a magnet spectrometer.

262

Absolute Measurement of Hadronic Branching Fractions of the D_s^+ Meson  

CERN Document Server

The branching fractions of D_s meson decays serve to normalize many measurements of processes involving charm quarks. Using 298 /pb of e+ e- collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for eight D_s decays with a double tag technique. In particular we determine the branching fraction B(D_s -> K- K+ pi+) = (5.50 +- 0.23 +- 0.16)%, where the uncertainties are statistical and systematic respectively. We also provide partial branching fractions for kinematic subsets of the K- K+ pi+ decay mode.

Alexander, J; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A G; Libby, J; Powell, A; Wilkinson, G; Ecklund, K M; Love, W; Savinov, V; López, A; Méndez, H; Ramírez, J; Ge, J Y; Miller, D H; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Rademacker, J; Asner, D M; Edwards, K W; Naik, P; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L

2008-01-01

263

Absolute determination of activity per mass and half-life measurements of 152Eu.  

Science.gov (United States)

A solution of 152Eu was absolutely standardized by the 4pi beta (PPC)-gamma (HPGe) coincidence counting method as part of an intercomparison program coordinated by Bureau International des Poids et Mesures. The measured activity has been used to determine the calibration factor of the LNMRI reference ionization chamber for 152Eu. The half-life of 152Eu was also determined by means of a 4pi gamma ionization chamber to be (4963.6+/-15.3) days, and compared with others published values. PMID:11839011

da, SilvaCarlosJ; Delgado, José U; Iwahara, Akira; Tauhata, Luiz; Poledna, Roberto; Alves, Rex N

2002-01-01

264

Measurement of the absolute branching ratios for semileptonic K+- decays with the KLOE detector.  

OpenAIRE

Using a sample of over 600 million phi->K+K- decays collected at the Dafne e+e- collider, we have measured with the KLOE detector the absolute branching ratios for the charged kaon semileptonic decays, K+/- -> p0 e nu (gamma) (Ke3) and K+/- -> p0 mu nu (gamma) (Kmu3). The results, BR(Ke3) = 0.04965 +/- 0.00038_{stat} +/- 0.00037_{syst} and BR(Kmu3) = 0.03233 +/- 0.00029_{stat} +/- 0.00026_{syst}, are inclusive of radiation. Accounting for correlations, we derive the ratio Km...

Ambrosino, Fabio; Massarotti, Paolo; Napolitano, Marco

2008-01-01

265

Measurement of the absolute and differential cross sections for 7Li(?, n0)6Li  

Energy Technology Data Exchange (ETDEWEB)

We have measured the cross section of the photoneutron reaction channel {sup 7}Li+{gamma}{yields}{sup 6}Li(g.s.)+n where the progeny nucleus is the ground state of {sup 6}Li. We obtained the absolute cross section at photon energies 10, 11, 12, 13, 15, 20, 25, 30, and 35 MeV and also the dependence of the cross section on polar angle for all but the highest photon energy. For the energies 10 to 15 MeV we were able to use linearly polarized photons to obtain the dependence of the cross section on the photon polarization.

W.A. Wurtz, R.E. Pywell, B.E. Norum, S. Kucuker, B.D. Sawatzky, H.R. Weller, M.W. Ahmed, S. Stave

2011-10-01

266

Absolute timing measurements of the Ni-like Pd and Sn soft-x-ray lasers  

Science.gov (United States)

The absolute time of emission of the x-ray laser output with respect to the arrival of a 100-ps pump pulse has been measured with the aid of a calibrated timing fiducial. The results show the x-ray laser to appear up to 60ps(80ps) before the peak of the pump pulse in the case of the Sn (Pd) x-ray laser, which is in good agreement with simulations obtained from the LASNEX and CRETIN codes. The pulse duration was found to be ˜45ps for both the Sn and the Pd x-ray lasers.

Staub, F.; Braud, M.; Balmer, J. E.; Nilsen, J.

2005-10-01

267

Absolute timing measurements of the Ni-like Pd and Sn soft-x-ray lasers  

International Nuclear Information System (INIS)

The absolute time of emission of the x-ray laser output with respect to the arrival of a 100-ps pump pulse has been measured with the aid of a calibrated timing fiducial. The results show the x-ray laser to appear up to 60 ps (80 ps) before the peak of the pump pulse in the case of the Sn (Pd) x-ray laser, which is in good agreement with simulations obtained from the LASNEX and CRETIN codes. The pulse duration was found to be ?45 ps for both the Sn and the Pd x-ray lasers

268

Compact activation detectors for measuring of absolute neutron yield generated by powerful pulsed plasma installations  

International Nuclear Information System (INIS)

A system for measuring of absolute neutron yield and its spatial anisotropy is described. The system was developed in the LPI (Lebedev Physical Institute) and destined for study properties of neutron emission of pulse plasma installations such as Plasma Focus (PF), z-pinches and others. The system consists of transported compact activation detectors and small optically isolated neutron activation counter with 4th digit data output to LCD display. The electronic unit is built on the TTL standard. In power supply of the system the small-size accumulators are used. (author)

269

NIST MQA for environmental radioactivity measurements  

International Nuclear Information System (INIS)

The Ionizing Radiation Division of the National Institute of Standards and Technology (NIST) has implemented several quality assurance programs to provide a consistent basis for environmental-level national and international ionizing radiation measurement credibility and comparability. These programs cut across a variety of sectors that include: (1) personnel protection; (2) survey-instrument calibration; (3) environmental radiochemistry and (4) radiobioassay. The four basic elements of the MQA programs are: (1) conformance to promulgated consensus criteria; (2) documented in-house quality assurance and control practice; (3) periodic performance evaluations using appropriate testing materials and instruments; and (4) periodic on-site assessments by technical experts. The periodic performance evaluations are important for the demonstration of measurement traceability to the national and international physical standards. Traceability testing, however, must be augmented by the other elements to provide the strongest rationale for measurement assurance. This paper will describe the NIST programs and future directions for new programs. (author)

270

Measuring the absolute position of EELS ionisation edges in a TEM  

International Nuclear Information System (INIS)

Measurements of absolute positions of electron energy loss spectroscopy (EELS) core-loss edges in a transmission electron microscopy (TEM) are hampered by noticeable errors caused by instabilities of the primary energy of the incident electrons. These instabilities originate from a continuous drift and random ripple of the high tension and are unavoidable in the present generation of TEM and scanning TEM microscopes. However, more precise measurements are desired, for instance, to study the shift of the edge onset between atoms of different valency or chemical environment, the so-called chemical shift. A solution to this problem is presented by collecting a series of short low-loss acquisitions immediately followed by core-loss ones. To ensure a minimal time lapse between core-loss and low-loss acquisitions, all operations must be computer controlled. Accumulation of a number of acquisitions and their summation corrected for energy drift allows to cancel the energy instabilities and to relate the core-loss EELS spectra to the absolute energy scale. A practical algorithm is presented as well as the necessary calibrations for such a procedure. Also, examples of spectra collected using this principle and the resulting measured chemical shifts in several metal-oxides are presented

271

Measuring the absorbed radioactivity during a flight  

International Nuclear Information System (INIS)

This paper presents the new system SIEVERT developed by the General Direction of the Civil Aviation (DGAC) to measure the radiations doses absorbed from cosmic radiation. The system is available on the Internet site: www.sievert-system.org. (A.L.B.)

272

Ameliorative measures during radioactive contamination of soils  

International Nuclear Information System (INIS)

While studying the effect after the accident on Chernobyl power station on agroindustrial production and in the corse of a number of protective agroameliarative measures were found basic regularities of soil chemistry of radionuclides and their accumulation in agricultural crops depending on soil properties and biological peculiarities of plants

273

Absolute fission cross section measurement on 236U at 2.6 MeV neutron energy  

International Nuclear Information System (INIS)

The fission cross section of 236U at 2.6 MeV neutron energy was measured absolutely applying the time correlated associated particle method. The experimental set-up is described, errors and corrections are given

274

IAEA-MEL's AQCS programme for marine radioactivity measurements  

International Nuclear Information System (INIS)

The main objectives of the IAEA-MEL's Analytical Quality Control Services (AQCS) for marine radioactivity measurements are discussed and future plans for the organization of intercomparison exercises and the production of certified reference materials are presented. The new developments should also include implementation of quality assurance programmes in Member States' laboratories, training in quality management and accreditation programmes. (author)

275

Gamma, radon, natural radioactivity measurements in Chile  

International Nuclear Information System (INIS)

Different natural radiation measurements, performed since 1983, are analysed and discussed regarding the average effective population dose. A decade of absorbed gamma dose measurements in air (1983-93), were carried out using compensated TLD detectors, during long periods of integration time and with a network of 11 stations, along the country, from Arica to the Antarctic territory. An indoor Rn-222 and gamma survey dwellings, in high background zones, underground mines and drinking water was started in 1988 using different kind of detectors, including electret radon chambers. The methods, dose assessments and results are presented and discussed in the frame of worldwide average effective population doses. None of the average effective doses found over the evaluated areas, exceed the comparison levels. (author)

276

Measurements of absolute total cross sections for electron scattering from triatomic polar molecules: SO2 and H2S  

International Nuclear Information System (INIS)

Absolute total electron-scattering cross sections (TCSs) have been measured in the energy range from 0.5 to 370 eV for SO2 and from 6 to 370 eV for H2S molecules. Measurements have been carried out using modified electron spectrometer working in a linear transmission mode. The present results are compared to published experimental TCS data. Some aspects important for achieving accurate absolute total cross sections in an electron transmission experiment are discussed

277

PREMOS Absolute Radiometer Calibration and Implications to on-orbit Measurements of the Total Solar Irradiance  

Science.gov (United States)

On orbit measurements starting in the late 1970's, have revealed the 11 year cycle of the Total Solar Irradiance (TSI). However, the absolute results from individual experiments differ although all instrument teams claim to measure an absolute value. Especially the data from the TIM/SORCE experiment confused the community as it measures 0.3 % lower than the other instruments, e.g. VIRGO/SOHO by PMOD/WRC, which clearly exceeds the uncertainty stated for the absolute characterization of the experiments. The PREMOS package on the PICARD platform launched in June 2010 is the latest space experiment by PMOD/WRC measuring the TSI. We have put great effort in the calibration and characterization of this instrument in order to resolve the inter-instrument differences. We performed calibrations at the National Physical Laboratory (NPL) in London and the Laboratory for Atmospheric and Space Physics (LASP) in Boulder against national SI standards for radiant power using a laser beam with a diameter being smaller than the aperture of the instrument. These measurements together with the World Radiometric Reference (WRR) calibration in Davos allowed to compare the WRR and the SI radiant power scale. We found that the WRR lies 0.18 % above the SI radiant power scale which explains a part of the VIRGO-TIM difference. The Total solar irradiance Radiometer Facility (TRF) at the LASP allows to generate a beam that over fills the apertures of our instruments, giving the presently best available representation of solar irradiance in a laboratory. These irradiance calibrations revealed a stray light contribution between 0.09 and 0.3 % to the measurements which had been underestimated in the characterization of our instruments. Using the irradiance calibrations, we found that the WRR lies 0.32 % above the TRF scale which in turn explains the full VIRGO-TIM difference. The first light PREMOS measurements in space confirmed our findings. If we use the WRR calibration, PREMOS yields a TSI value of 1365.5 ± 1.2 W/m2 (k=1) which is in excellent agreement with VIRGO (1365.4 W/m2). Else, applying the TRF calibration to PREMOS, we obtain a TSI value of 1360.9 ± 0.4 W/m2 (k=1) which is in excellent agreement with TIM (1361.3 W/m2).

Fehlmann, A.; Kopp, G.; Schmutz, W. K.; Winkler, R.; Finsterle, W.; Fox, N.

2011-12-01

278

Absolute calibration of in vivo measurement systems using magnetic resonance imaging and Monte Carlo computations  

International Nuclear Information System (INIS)

Lawrence Livermore National Laboratory (LLNL) is currently investigating a new method for obtaining absolute calibration factors for radiation measurement systems used to measure internally deposited radionuclides in vivo. This method uses magnetic resonance imaging (MRI) to determine the anatomical makeup of an individual. A new MRI technique is also employed that is capable of resolving the fat and water content of the human tissue. This anatomical and biochemical information is used to model a mathematical phantom. Monte Carlo methods are then used to simulate the transport of radiation throughout the phantom. By modeling the detection equipment of the in vivo measurement system into the code, calibration factors are generated that are specific to the individual. Furthermore, this method eliminates the need for surrogate human structures in the calibration process. A demonstration of the proposed method is being performed using a fat/water matrix

279

Absolute neutron emission rate measurement of a 252Cf source by the manganous sulfate bath method  

International Nuclear Information System (INIS)

A standard program for the absolute neutron emission rate measurement of a 252Cf source by the manganous sulfate bath method has been completed for the standardization of neutron source measurements. The MnSO4 circulation system enables the 56Mn activity to be measured during activation of the bath by the neutron source. The neutron capture cross section ratio of hydrogen to manganese has been determined to be 0.02506 by varying the manganese concentration in the MnSO4 solution. From the graphical analysis of a straight line fitted to the six sets of data, the observed neutron emission rate was 2.544 x 107 n/s for the 252Cf source at the reference data, January 1, 1987. (orig.)

280

A novel method for an absolute luminosity measurement at LHCb with beam-gas imaging  

International Nuclear Information System (INIS)

A novel technique to measure the absolute luminosity at the Large Hadron Collider (LHC) using beam-gas interactions has been successfully used in the LHCb experiment. A gas injection device (SMOG) has been installed in the LHCb experiment to increase the pressure around the interaction point during dedicated fills. The Beam-Gas Imaging method (BGI) has now the potential to surpass the accuracy of the commonly used *van der Meer scan* method (VDM). The technique has been used in 10 LHC fills during 2012 including and also provided a first luminosity measurement for proton-lead collisions. This talk presents the principles of the gas injection and the improvements reached with the increased pressure. Furthermore the gas injection increased the accuracy measurement of the so-called ghost charges and also intensities per bunch. Those uncertainties are becoming the dominating factor because the uncertainty on the total beam current have been reduced.

281

An absolute 3D measurement method using a 2D pattern based on digital moire  

Science.gov (United States)

With a remarkable evolution in the development of digital cameras, non-contact 3D measurement using computer vision has been rapidly developing in the past few decades. Excellent and well-accepted techniques include digital moire and stereo vision. An obvious drawback of digital moire is that it is not applicable to the measurement of significant discontinuities, which is common in this area of research. And in the process of measurement, error propagation is inevitable, especially under the condition of missing points. The reason for this shortcoming lies in its relative coding scheme. For stereo vision, it is based on triangulation which leads to an absolute measurement. However, correspondence searching and resolution limitation of measurement of lacking features are two of the major unsolved problems of stereo vision systems. Inspired by these two well-developed techniques, an absolute measuring method based on structured light is developed in this research, requiring only a camera and a projector. The philosophy behind the coding scheme is a hybrid of relativity to the center and absoluteness, or independence on every single point. The mathematical model of the system is described and theorems that relate to the guidance of designing such a system are introduced. Two important factors determine the accuracy of the 3D measurement: correspondence matching and calibration of the camera and the projector' parameters. For the correspondence matching, an image processing method is developed. Image subtraction, edge detection, grid permutation and establishment of sub-coordinate-systems are included in the algorithm. Aiming at the discontinuity measurement, discontinuous borders are marked out first by using a Gabor filter first. Epipolar geometry is then utilized in the process of searching out each corresponding points accurately on the image plane. Sub-pixel accuracy for correspondence matching can be achieved in this way. The second factor that affects the accuracy of the measurement system is concerned with the calibration of the whole system. A convenient calibration method for structured light systems is developed in this research. This calibration method significantly simplifies the calibration procedures, and experimental results are presented for the verification of this calibration method. And experiments verify accuracy of the whole measurement system. And its advantages over digital moire and stereo vision are presented and verified by experiments. However, this calibration method for structured light system is applicable to the existing methods that are based on the least squares minimization effort. The assumptions made for the calibration system are not suitable to the nonlinear stereo vision system. Moreover, the 2D planar pattern used in existing calibration methods cannot provide 3D information in the 3D space. To move it among different views will inadvertently introduce additional mechanical errors. An iterative calibration method is developed in order to solve the existing problems in the state-of-the-art calibration methods for stereo vision systems. It is the first time that an iterative calibration method is developed to solve the calibration of a two-camera system's calibration with iterations in the 3D space. Derivations are described for this iterative calibration algorithm using feedback control theory. Furthermore, the calibration target is designed and manufactured under specifications defined by the task has been created for. Experiments show the developed iterative calibration method based on feedback control can achieve convergent parameters. With the calibrated parameters, 3D measurement of the calibration target verifies the correctness and accuracy of this iterative calibration method. Hence, the contributions of this work are significant. An absolute 3D measurement system based on a 2D pattern using digital moire has been developed. At the same time, a novel calibration method for such a system has also been proposed and verified in this work. For investigation of calibration method on

Liao, Jiarui

282

ABSOLUTE MEASUREMENT OF THE POLARIZATION OF HIGH ENERGY PROTON BEAMS AT RHIC  

Energy Technology Data Exchange (ETDEWEB)

The spin physics program at the Relativistic Heavy Ion Collider (RHIC) requires knowledge of the beam polarization to better than 5%. Such a goal is made the more difficult by the lack of knowledge of the analyzing power of high energy nuclear physics processes. To overcome this, a polarized hydrogen jet target was constructed and installed at one intersection region in RHIC where it intersects both beams and utilizes the precise knowledge of the jet atomic hydrogen beam polarization to measure the analyzing power in proton-proton elastic scattering in the Nuclear Coulomb Interference (CNI) region at the prescribed RHIC proton beam energy. The reverse reaction is used to assess the absolute beam polarization. Simultaneous measurements taken with fast high statistics polarimeters that measure the p-Carbon elastic scattering process also in the CNI region use the jet results to calibrate the latter.

MAKDISI,Y.; BRAVAR, A. BUNCE, G. GILL, R.; HUANG, H.; ET AL.

2007-06-25

283

A novel method for an absolute luminosity measurement at LHCb with beam-gas imaging  

Energy Technology Data Exchange (ETDEWEB)

A novel technique to measure the absolute luminosity at the Large Hadron Collider (LHC) using beam-gas interactions has been successfully used in the LHCb experiment. A gas injection device (SMOG) has been installed in the LHCb experiment to increase the pressure around the interaction point during dedicated fills. The Beam-Gas Imaging method (BGI) has now the potential to surpass the accuracy of the commonly used *van der Meer scan* method (VDM). The technique has been used in 10 LHC fills during 2012 including and also provided a first luminosity measurement for proton-lead collisions. This talk presents the principles of the gas injection and the improvements reached with the increased pressure. Furthermore the gas injection increased the accuracy measurement of the so-called ghost charges and also intensities per bunch. Those uncertainties are becoming the dominating factor because the uncertainty on the total beam current have been reduced.

Barschel, Colin [RWTH Aachen, III. Physikalisches Institut A (Germany)

2013-07-01

284

Measurement of radioactivity in agricultural products (1995-96)  

International Nuclear Information System (INIS)

Radioactivity levels and concentration of radionuclides in agricultural products like beans, sesame, potato, etc. were measured by using Low Level Beta/Alpha System and high resolution gamma-ray spectrometry system. The levels of radioactivity were found to be less than the Derivedc Intervention Level adopted by FAO/WHO Codex Alimentarius Commission in 1991 (IAEA BSS safety series No. 115-1). No artificial radionuclides such as fission products, activation products were not found whereas radionuclides found in the samples are only natural occurring radionuclide, K-40. (author)

285

Measurement of nuclear cross sections using radioactive beams  

International Nuclear Information System (INIS)

One of the main applications of the production and use of nuclear radioactive beams is the measurement of nuclear cross sections. In this work is used a 6 He nuclear radioactive beam (? emitting with half life 806.7 ms) for the study of the reaction 6 + 209 Bi which could have several products. This investigation was realized in collaboration with the personnel of the Nuclear Structure laboratory at the University of Notre Dame (U.S.A.) and the National institute of Nuclear Research and CONACyT by Mexico. (Author)

286

Measurement of radioactive dust in high altitude air  

International Nuclear Information System (INIS)

The radioactivities of airborne dust in samples were measured. The samples had been collected at high altitude by the Japan Air Self-Defense Force from April 2006 to March 2007. The data were obtained for the gross beta activity, gamma nuclide determination and radiochemical analysis. It is shown that there is no appreciable difference between the activity levels of this time and ones of the year before. Seasonal variations are little pronounced. It is found that the radioactivity have been stable in the low level at high altitude. (author)

287

Construction for measuring the spatial distribution of a radioactive material  

International Nuclear Information System (INIS)

The system comprises a detector placed in the neighbourhood of a radio-active point source. The detector is responsible to gamma-photons emitted from a target at the angle given by the Compton Law. The energy concentration in the beams sent out at various angles is measured and used to obtain on indication of the distribution of radioactive material. The detector is in two parts, the second being greater than the first. The system includes an electronic analysis circuit with an analogue-digital converter and may produce a display. (G.C.)

288

Development of Nondestructive Measuring Technique of Environmental Radioactive Strontium  

Science.gov (United States)

The Fukushima first nuclear power plant accident was triggered by the Japanese big earthquake in 2011. The main radioactivity concerned after the accident are I-131 (half-life 8.0 days), Cs-134 (2.1 years) and 137 (30 years), Sr-89 (51 days) and 90 (29 years). We are aiming to establish a new detection technique which enables us to realize quantitative evaluation of the strontium radioactivity by means of nondestructive measurement without chemical separation processing, which is concerned to be included inside foods, environmental water and soil around us, in order to prevent us from undesired internal exposure to the radiation.

Saiba, Shuntaro; Okamiya, Tomohiro; Tanaka, Saki; Tanuma, Ryosuke; Yoshida, Tatsuru; Murata, Jiro

289

The First Absolute TEC Measurements Using the Scintillation and Ionospheric TEC Receiver in Space (CITRIS)*  

Science.gov (United States)

The space-based multi-band CITRIS receiver records total electron content (TEC) and radio scintillations from satellite beacons in low-earth-orbit plus the global network of ground DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) beacons. The measurement of ionospheric TEC provides inputs for space-weather models over remote regions of the Earth and allows for tracking of ionospheric disturbances. The CITRIS satellite-to-satellite TEC measurement uses the differential phase technique. The CITRIS receiver is currently in orbit at 560 km altitude on the STPSat1 satellite at 35 degrees inclination. CITRIS records TEC and radio scintillations from beacon transmitters on the Taiwan FORMOSAT3 at 150/400/1067 MHz, DMSP/F15, RADCAL, GFO and COSMOS at 150/400 MHz plus other satellites in low earth orbit. The ground-based DORIS geodesy beacons operate at 401/2036 MHz. The innovative satellite-to-satellite measurements provide new capacities. Satellite-to-satellite measurements have three stages: 1) ionospheric occultation at large separations, 2) minimum distance TEC sampling when the beacon passes directly over the receiver and 3) a second occultation. Absolute TEC is obtained by extrapolation to zero satellite separations. In such cases, it is possible to retrieve absolute TEC with less than 0.1 TECU errors. Initial tests using CITRIS data in data-assimilation space weather models shows the value of the technique. We will report on the first year of measurements from the CITRIS receiver. Future space missions would benefit from flying CITRIS receivers to give global radio measurements of the ionosphere at 150, 400, 1067, and 2036 MHz. *Supported by ONR

Siefring, C. L.; Bernhardt, P. A.

2008-05-01

290

(n, ?) measurements on radioactive isotopes with DANCE  

International Nuclear Information System (INIS)

The Detector for Advanced Neutron Capture Experiments (DANCE) at the Los Alamos National Laboratory (LANL) is designed as a high efficiency, highly segmented 4? BaF2 detector for calorimetrically detecting gamma rays following a neutron capture. Coupled with the neutron spallation source at the Los Alamos Neutron Science Center (LANSCE), DANCE measurements on unstable isotopes in the energy range between 10 meV and 500 keV will provide many of the missing key reactions that are needed to understand the nucleosynthesis of the heavy elements and will also provide vital information for the design of future reactor concepts

291

ROKO-Database of the environmental radioactivity measurements in Slovenia  

International Nuclear Information System (INIS)

ROKO is the acronym of the Environmental Radioactivity in Slovenian language Radioaktivnost v OKOlju. Computer database ROKO contains data of all measurements of the radioactivity in the environment in Slovenia. Data about radioactivity in the environment have been collected in Slovenia more or less regularly since 1961 on. Most results are gathered in the form of paper reports. Slovenian Nuclear Safety Administration (SNSA) has initiated the project of transfer of all those data into the electronic form and making it available for easy research. The database is designed so, that it contains all records, relevant for any kind of analyses and for the transfer to the international data systems. By the end of the summer 2005 a major part of data from previous years have already been transferred into the database and the user interface software is under development. It will allow the users to examine individual data records, to plot time history graphs or geographical contour plots. (author)

292

Measurement and analysis of radioactive substances; Mesure et analyse de substances radioactives  

Energy Technology Data Exchange (ETDEWEB)

Here are gathered the abstracts presented to the 3. summer university of the year 2001 whose main themes were the destructive (5 conferences) and nondestructive (8 conferences) analyses applied to nuclear industry. The points of view of different organisms (as DSIN: Directorate for the Safety of Nuclear Installations, IPSN: Institute of Nuclear Protection and Safety, OPRI: Office of Protection against Ionizing Radiations, TUI: Institute for Transuranium Elements, COGEMA, EDF: Electric Utilities, ANDRA: French National Agency for Radioactive Waste Management, CRLC Val d'Aurelle, France) concerning the needs involved in nuclear facilities control, the methods of radionuclide speciation in use internationally, the measurements and analyses of radioactive substances are given too as well as some general concepts concerning 1)the laser-matter interaction 2)the ions production 3)the quality applied to the measurements and analyses 4)the standard in activity metrology. (O.M.)

NONE

2001-07-01

293

Radioactivity measurements in Egyptian Phosphate Mines and Their Significance As a Source of Hazardous Radioactive Waste  

International Nuclear Information System (INIS)

Phosphate mines that may contain radioactive traces in the composition of their ores represent source of hazardous radioactive waste in the environment. Radioactivity measurements have been conducted in nine underground phosphate mines in the Egyptian Eastern Desert in order to estimate the occupational radiation exposure of mine workers in those mining sites. Measurements were carried out of airborne radon and its short- lived decay products (progeny) and thoron progeny, as well as radiation from mines walls, ceilings and floors. Conventional, well established techniques, methods and instrumentation were used to make these measurements. Comparison of experimental data and theoretical predictions showed partial agreement between these two sets of data. This result is partly attributed to the complex layout of these mines, which causes undesirable ventilation conditions, such as recirculation airflow patterns, which could not be adequately identified or quantified. The radiation data obtained were used to estimate the maximum Annual Dose (MAD), and other important occupational radiation exposure variables. These calculations indicate that in eight out of the nine mines surveyed, the MAD exceeded (by a factor of up to 7) the maximum recommended level by ICRP 60. Numbers of suggestions are made in order to reduce the MAD in the affected mines. This study could help in the estimation of the environmental impact of these mine operations on the environment

294

Measurement of distribution of low-level internal radioactivity  

International Nuclear Information System (INIS)

A new technique for measuring distribution of a small amount of radioactivity in the human body is described. The distribution is obtained by analysing the difference in gamma-ray pulse height distributions measured around the body, which contains information for not only unscattered, but also scattered rays within the body, by use of the response function method. The analysis is performed by the least squares method with the condition that the radioactivity is greater than or equal to zero. Basic experiments involving the measurement of two-dimensional radioactivity distribution in a homogeneous acrylate block (40 cmW x 20 cmH x 50 cmL) containing two 137Cs point sources (0.8 and 1.0 ?Ci) were made using gamma-ray counts measured by twenty 2'' ? x 2'' H NaI(Tl) scintillators arranged on a circle, and the response functions calculated by the Monte Carlo technique or obtained by measurements. The distribution on a 10 x 5 mesh division was successfully analysed using both 20 unscattered rays data and 100 scattered rays data, for a measuring time of 10 min. The mesh size was 4 cm x 4 cm, which was about one-half that possible when analysing only unscattered rays. (author)

295

Absolute activity measurement of 152Eu sources with a single detector  

International Nuclear Information System (INIS)

We investigated the possibility of absolute source activity measurements by a single gamma spectrometer. The measurements were performed for three (point, cylinder and Marinelly shaped) calibrated 152Eu sources. Making use of data on peak, sum-peak and total spectrum area in the single spectrum, we developed the activity determination method based on the dominant gamma cascades in the 152Eu decay. We have shown that spectral data of 152Eu point and Marinelli shaped source can yield activity information with uncertainty below 10%. - Highlights: ? Peak, sum-peak and total spectrum area in single spectrum were used for activity determination. ? For the 152Eu source the activity was determined from the dominant gamma cascades in the decay. ? The activity of point and Marinelly shaped sources was determined with uncertainty of less than 10%.

296

Absolute activity measurement of {sup 152}Eu sources with a single detector  

Energy Technology Data Exchange (ETDEWEB)

We investigated the possibility of absolute source activity measurements by a single gamma spectrometer. The measurements were performed for three (point, cylinder and Marinelly shaped) calibrated {sup 152}Eu sources. Making use of data on peak, sum-peak and total spectrum area in the single spectrum, we developed the activity determination method based on the dominant gamma cascades in the {sup 152}Eu decay. We have shown that spectral data of {sup 152}Eu point and Marinelli shaped source can yield activity information with uncertainty below 10%. - Highlights: > Peak, sum-peak and total spectrum area in single spectrum were used for activity determination. > For the {sup 152}Eu source the activity was determined from the dominant gamma cascades in the decay. > The activity of point and Marinelly shaped sources was determined with uncertainty of less than 10%.

Nemes, T. [Faculty of Engineering, University of Novi Sad, Trg Dositeja Obradovica 6, 21000 Novi Sad (Serbia); Mrda, D. [Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad (Serbia); Bikit, I., E-mail: bikit@df.uns.ac.rs [Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad (Serbia)

2011-08-21

297

A method to measure the absolute branching fractions of $\\Lambda_c$ decays  

CERN Document Server

It is proposed to exploit the decay of the meson $\\mbox{B}^+ \\rightarrow p \\pi^+ \\pi^+ \\overline{\\Sigma}_c^{--}$ and of its charge conjugate $B^-$ copiously produced at LHC to obtain a sample of $\\Lambda_c$ baryons through the strong decay $\\Sigma_c \\rightarrow \\Lambda_c \\pi$. The sample thus obtained is not affected by biases typically introduced by selections that depend on specific decay modes. Therefore it allows a measurement of the absolute branching fraction for the decay of the $\\Lambda_c$ baryon into $ p K \\pi$ or into other observable final states to be performed in a model independent manner. The accuracy that can be achieved with this method is discussed and it is shown that it would be either competitive with or an improvement over current measurements.

Contu, Andrea; Oldeman, Rudolf Gerhard Christiaan; Saitta, Biagio; Vacca, Claudia

2014-01-01

298

Absolute reflectivity measurements of multilayer mirrors in the soft x-ray region  

International Nuclear Information System (INIS)

Multilayer soft X-ray mirrors were deposited by using a triode dc sputtering system, equipped with an accurate method of film thickness monitoring which enables the thickness to be controlled with an accuracy of better than 0.1 A. Absolute reflectivity measurements of Ni-C and W-C multilayers at ? = 44.79 A (C K?) in the first and second order Bragg Peaks, and at ? = 67.8 A (B K?) only in the first order were carried out. The incident beam is previously polarized by two parallel plane multilayer mirrors fixed at an angle close to Brewster's one (? ? 450). Thus the measured reflectivities are not affected by a progressive variation of the P component. The preliminary results obtained at ? = 113 A (BeK?) are also presented

299

Absolute reflectivity measurements at 44.79 A of sputter deposited multilayer x-ray mirrors.  

Science.gov (United States)

Multilayer x-ray mirrors have been deposited using a dc triode sputtering system, which incorporates an accurate method of thickness monitoring based on the dependence of the deposition rate on the target current. Thickness can be controlled with an accuracy of better than 0.1 A. High efficiency W-C and Ni-C multilayer mirrors have been synthesized and tested at 1.54-A (CuKoalpha) and 44.79-A (CKalpha). Absolute reflectivity measurements at lambda = 44.79-A (CKalpha) have been carried out. In this case the incident beam is previously polarized by a premonochromator equipped with a pair of parallel-plane multilayer mirrors fixed at an angle close to the Brewster (theta ? 45 degrees ). Thus the measured reflectivities are not affected by a progressive variation of the P-component. PMID:20556133

Arbaoui, M; Barchewitz, R; Sella, C; Youn, K B

1990-02-01

300

Precise measurement of the absolute fluorescence yield of the 337 nm band in atmospheric gases  

CERN Document Server

A measurement of the absolute fluorescence yield of the 337 nm nitrogen band, relevant to ultra-high energy cosmic ray (UHECR) detectors, is reported. Two independent calibrations of the fluorescence emission induced by a 120 GeV proton beam were employed: Cherenkov light from the beam particle and calibrated light from a nitrogen laser. The fluorescence yield in air at a pressure of 1013 hPa and temperature of 293 K was found to be $Y_{337} = 5.61\\pm 0.06_{stat} \\pm 0.21_{syst}$ photons/MeV. When compared to the fluorescence yield currently used by UHECR experiments, this measurement improves the uncertainty by a factor of three, and has a significant impact on the determination of the energy scale of the cosmic ray spectrum.

Ave, M; Curry, E; Di Carlo, P; Di Giulio, C; Luis, P Facal San; Gonzales, D; Hojvat, C; Hörandel, J; Hrabovsky, M; Iarlori, M; Keilhauer, B; Klages, H; Kleifges, M; Kuehn, F; Li, S; Monasor, M; Nozka, L; Palatka, M; Petrera, S; Privitera, P; Ridky, J; Rizi, V; D'Orfeuil, B Rouille; Salamida, F; Schovanek, P; Smida, R; Spinka, H; Ulrich, A; Verzi, V; Williams, C

2012-01-01

301

Absolute measurement of surface and bulk absorption in DUV optics from temperature induced wavefront deformation.  

Science.gov (United States)

A measurement system for quantitative determination of both surface and bulk contributions to the photo-thermal absorption in DUV optics was developed. It is based upon a Hartmann-Shack wavefront sensor with a sensitivity of ~?/10000 rms, accomplishing precise on-line monitoring of wavefront deformations of a collimated test laser beam transmitted perpendicular through the excimer laser-irradiated site of a cuboid sample. Caused by the temperature dependence of the refractive index as well as thermal expansion, the initially plane wavefront of the test laser is distorted into a cylindrical shape, with bending ends towards the surface. Sign and magnitude depend on index change and expansion. By comparison with thermal theory, this transient wavefront distortion yields a quantitative absolute measure of bulk and surface absorption losses in the sample. First rresults for fused silica are presented. PMID:20941050

Schäfer, Bernd; Schöneck, Matthias; Bayer, Armin; Mann, Klaus

2010-10-11

302

Diagnostics principle of microwave cut-off probe for measuring absolute electron density  

Energy Technology Data Exchange (ETDEWEB)

A generalized diagnostics principle of microwave cut-off probe is presented with a full analytical solution. In previous studies on the microwave cut-off measurement of weakly ionized plasmas, the cut-off frequency ?{sub c} of a given electron density is assumed to be equal to the plasma frequency ?{sub p} and is predicted using electromagnetic simulation or electric circuit model analysis. However, for specific plasma conditions such as highly collisional plasma and a very narrow probe tip gap, it has been found that ?{sub c} and ?{sub p} are not equal. To resolve this problem, a generalized diagnostics principle is proposed by analytically solving the microwave cut-off condition Re[?{sub r,eff}(??=??{sub c})]?=?0. In addition, characteristics of the microwave cut-off condition are theoretically tested for correct measurement of the absolute electron density.

Jun, Hyun-Su, E-mail: mtsconst@kaist.ac.kr [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)

2014-08-15

303

ArtDeco: A beam deconvolution code for absolute CMB measurements  

CERN Document Server

We present a method for beam deconvolution for cosmic microwave background (CMB) anisotropy measurements. The code takes as input the time-ordered data, along with the corresponding detector pointings and known beam shapes, and produces as output the harmonic a_Tlm, a_Elm, and a_Blm coefficients of the observed sky. From these one can further construct temperature and Q and U polarisation maps. The method is applicable to absolute CMB measurements with wide sky coverage, and is independent of the scanning strategy. We test the code with extensive simulations, mimicking the resolution and data volume of Planck 30GHz and 70GHz channels, but with exaggerated beam asymmetry. We apply it to multipoles up to l=1700 and examine the results in both pixel space and harmonic space. We also test the method also in presence of white noise.

Keihänen, Elina

2012-01-01

304

Static Absolute Force Measurement for Preloaded Piezoelements Used for Active Lorentz Force Detuning System  

CERN Document Server

To reach high gradients in pulsed operation of superconducting (SC) cavities an active Lorentz force detuning compensation system is needed. For this system a piezoelement can be used as an actuator (other option is a magnetostrictive device). To guarantee the demanded lifetime of the active element, the proper preload force adjustment is necessary. To determine this parameter an absolute force sensor is needed which will be able to operate at cryogenic temperatures. Currently, there is no calibrated commercial available sensor, which will be able to measure the static force in such an environment. The authors propose to use a discovered phenomenon to estimate the preload force applied to the piezoelement. The principle of the proposed solution based on a shape of impedance curve, which changes with the value of applied force. Especially, the position of resonances are monitored. No need of specialized force sensor and measurement in-situ are additional advantages of proposed method.

Sekalski, S P; Sekalski, S P

2004-01-01

305

Measurement of absolute detection efficiencies of a microchannel plate using the charge transfer reaction  

International Nuclear Information System (INIS)

A new method for determining the absolute detection efficiencies of a microchannel plate (MCP) detector is presented. This method uses a charge transfer reaction and can be applied to determine not only the detection efficiencies for ions but also those for neutral atoms. The measurements were carried out for Ar+ and neutral rare gas atoms (Ne, Ar, Kr and Xe) in the 0.5-4.8 keV energy range. The detection efficiencies for all species increase with increasing impact energy and approach the open area ratio of the MCP used (about 50%). The measured detection efficiencies were found to scale with the Lindhard, Scharff and Schiott formula for electronic stopping power at keV energies.

306

Absolute density measurement of SD radicals in a supersonic jet at the quantum-noise-limit.  

Science.gov (United States)

The absolute density of SD radicals in a supersonic jet has been measured down to (1.1 ± 0.1) × 10(5) cm(-3) in a modestly specified apparatus that uses a cross-correlated combination of cavity ring-down and laser-induced fluorescence detection. Such a density corresponds to 215 ± 21 molecules in the probe volume at any given time. The minimum detectable absorption coefficient was quantum-noise-limited and measured to be (7.9 ± 0.6) × 10(-11) cm(-1), in 200 s of acquisition time, corresponding to a noise-equivalent absorption sensitivity for the apparatus of (1.6 ± 0.1) × 10(-9) cm(-1) Hz(-1/2). PMID:24145480

Mizouri, Arin; Deng, L Z; Eardley, Jack S; Nahler, N Hendrik; Wrede, Eckart; Carty, David

2013-12-01

307

The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF  

Energy Technology Data Exchange (ETDEWEB)

The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; Sangster, T. C.; Shoup, M.; Ulreich, J. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Ashabranner, R. C.; Bionta, R. M.; Carpenter, A. C.; Felker, B.; Khater, H. Y.; LePape, S.; MacKinnon, A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2013-04-15

308

The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF.  

Science.gov (United States)

The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF. PMID:23635195

Casey, D T; Frenje, J A; Johnson, M Gatu; Séguin, F H; Li, C K; Petrasso, R D; Glebov, V Yu; Katz, J; Magoon, J; Meyerhofer, D D; Sangster, T C; Shoup, M; Ulreich, J; Ashabranner, R C; Bionta, R M; Carpenter, A C; Felker, B; Khater, H Y; LePape, S; MacKinnon, A; McKernan, M A; Moran, M; Rygg, J R; Yeoman, M F; Zacharias, R; Leeper, R J; Fletcher, K; Farrell, M; Jasion, D; Kilkenny, J; Paguio, R

2013-04-01

309

The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF  

International Nuclear Information System (INIS)

The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

310

GENERAL: A diode laser spectrometer at 634 nm and absolute frequency measurements using optical frequency comb  

Science.gov (United States)

This paper reports that two identical external-cavity-diode-laser (ECDL) based spectrometers are constructed at 634 nm referencing on the hyperfine B-X transition R(80)8-4 of 127I2. The lasers are stabilized on the Doppler-free absorption signals using the third-harmonic detection technique. The instability of the stabilized laser is measured to be 2.8 × 10-12 (after 1000 s) by counting the beat note between the two lasers. The absolute optical frequency of the transition is, for the first time, determined to be 472851936189.5 kHz by using an optical frequency comb referenced on the microwave caesium atomic clock. The uncertainty of the measurement is less than 4.9 kHz.

Yi, Lin; Yuan, Jie; Qi, Xiang-Hui; Chen, Wen-Lan; Zhou, Da-Wei; Zhou, Tong; Zhou, Xiao-Ji; Chen, Xu-Zong

2009-04-01

311

Diagnostics principle of microwave cut-off probe for measuring absolute electron density  

International Nuclear Information System (INIS)

A generalized diagnostics principle of microwave cut-off probe is presented with a full analytical solution. In previous studies on the microwave cut-off measurement of weakly ionized plasmas, the cut-off frequency ?c of a given electron density is assumed to be equal to the plasma frequency ?p and is predicted using electromagnetic simulation or electric circuit model analysis. However, for specific plasma conditions such as highly collisional plasma and a very narrow probe tip gap, it has been found that ?c and ?p are not equal. To resolve this problem, a generalized diagnostics principle is proposed by analytically solving the microwave cut-off condition Re[?r,eff(??=??c)]?=?0. In addition, characteristics of the microwave cut-off condition are theoretically tested for correct measurement of the absolute electron density

312

New measurement techniques of environmental radioactivity. Methods of surveying marine radioactivity  

International Nuclear Information System (INIS)

Measurements of radioactivity have been carried out in solution or suspension in sea-water, bottom sediments and specific marine organisms. The general approach to radionuclide measurement in seawater and bottom sediments has been concentration by coprecipitation, adsorption, ion exchange or solvent extraction. These methods employed are based primarily on shipboard collection of samples followed by land-based laboratory analyses and are too time-consuming. For rapid measurement, in situ measurement of seawater or seabed gamma-ray has developed. A gamma-ray detecting probe containing the NaI(Tl) scintillation or germanium detector is enclosed in a sealed cylinder. The measurements are made by suspending the probe in a 200-300 liter tank and passing seawater through the tank by means of ship deck pumping system, towing the probe across the seafloor, hanging down the probe to the seabed, or loading the probe on a remotely operated undersea vehicle. In situ measurement of gamma-ray in the marine environment has some application to a mineral exploration and to monitoring of sea areas which may become contaminated as the result of accidents or contamination incidents. This article reviews several gamma-ray detecting probes and describes the recent studies at JAERI on the development of a small electric-cooled Ge gamma-ray detector and a marine environmental radioactivity investigation system for in situ measurement of gamma-ray. (J.P.N.)

313

Absolute-scale measurement of Compton backscattering in germanium at 105.3 KeV  

International Nuclear Information System (INIS)

The differential cross section d2?/dEd? was measured at incident photon energy of 105.3 keV in germanium (Z = 32). The experimental method used in the present experiment was introduced by the present authors previously. In the measurements, one detector serves as target and detector of ejected electrons, and another detector as detector of Compton-scattered photons. 155Eu was used as the source of photons. It gives a complex multi-line spectrum. We found that fast (multiple) cascades influence little the data of the 105.3 keV crossover transition. The calculations of other non-single Compton detector-to-detector scattering processes were made. As an improvement to our previous calculations, we have taken into account the finite dimensions of the cylindrical active volume of the detectors. Accordingly, the calculation of the detector efficiency was also improved. The absolute scale of the experimental Compton-scattering cross section was determined by cross talk between the two detectors via characteristic K? and K? x-rays of germanium with accuracy better than few percents. The values of the experimental cross section d2?/dEd? have been compared with corresponding values calculated by the impulse approximation with Hartree-Fock (HF) and hydrogen-like wave functions. The impulse approximation with HF wave functions gives excellent agreement to the experimental cross section, while the impulse approximation with hydrogen like wave proximation with hydrogen like wave functions give fairly agreement. The accurate absolute-scale values of Compton-scattering cross section from the present measurement and those from our previous measurements clearly show that HF wave functions are much better than the hydrogen-like wave functions in the description of Compton scattering data. (author)

314

Absolute measurement of the number of neutrons per spontaneous fission of californium-252  

International Nuclear Information System (INIS)

The purpose of this experimental investigation was to determine an accurate absolute value of the total nu-bar for the spontaneous fission of 252Cf. The neutron emission rate and fission rate of a 0.5 microgram sample of Californium were measured separately, and their ratio used to derive a value for nu-bar. The neutron emission rate was determined by using The University of Michigan manganese bath system to compare the Californium sample with the internationally calibrated (Ra-?-Be) NBS-II neutron source. Correction factors necessary to account for the neutron energy spectrum differences of NBS-II and 252Cf were determined. Neutron losses from parasitic capture in the bath were calculated with the transport code ANISN. The difference in the source self-absorptions were measured. The leakage of fission neutrons was obtained by computation and experimentally verified. The absolute fission rate was measured independently in a fission chamber utilizing a heavy ion semiconductor detector with a variable limited solid angle geometry. A number of independent measurements with various geometries ranging from 2 x 10-5 to 6 x 10-4 steradian resulted in a consistent set of fission values. The corrected neutron emission rate and fission rate gave a value for average total number of neutrons per fission of 3.744 +- 0.023. All uncorrelated errors were summed in quadrature and were quoted as one standard deviation. The result is in good tandard deviation. The result is in good agreement with various evaluated values of this standard

315

Evaluation of the systematic shifts and absolute frequency measurement of a single Ca+ ion frequency standard  

Science.gov (United States)

This paper provides a detailed description of the 40Ca+ optical frequency standard uncertainty evaluation and the absolute frequency measurement of the clock transition, as a summary and supplement for the published papers of Yao Huang et al. (Phys Rev A 84:053841, 1) and Huang et al. (Phys Rev A 85:030503, 2). The calculation of systematic frequency shifts, expected for a single trapped Ca+ ion optical frequency standard with a "clock" transition at 729 nm is described. There are several possible causes of systematic frequency shifts that need to be considered. In general, the frequency was measured with an uncertainty of 10-15 level, and the overall systematic shift uncertainty was reduced to below a part in 10-15. Several frequency shifts were calculated for the Ca+ ion optical frequency standard, including the trap design, optical and electromagnetic fields geometry and laboratory conditions, including the temperature condition and the altitude of the Ca+ ion. And we measured the absolute frequency of the 729-nm clock transition at the 10-15 level. An fs comb is referenced to a hydrogen maser, which is calibrated to the SI-second through the Global Positioning System (GPS). Using the GPS satellites as a link, we can calculate the frequency difference of the two hydrogen masers with a long distance, one in WIPM (Wuhan) and the other in National Institute of Metrology (NIM, Beijing). The frequency difference of the hydrogen maser in NIM (Beijing) and the SI-second calculated by BIPM is published on the BIPM web site every 1 month, with a time interval of every 5 days. By analyzing the experimental data obtained within 32 days of a total averaging time of >2 × 106 s, the absolute frequency of the 40Ca+ 4 s 2 S 1/2-3 d 2D5/2 clock transition is measured as 411 042 129 776 393.0 (1.6) Hz with a fractional uncertainty of 3.9 × 10-15.

Huang, Yao; Liu, Peiliang; Bian, Wu; Guan, Hua; Gao, Kelin

2014-01-01

316

Discordant gross radioactivity measurements of natural and treated waters  

International Nuclear Information System (INIS)

The periodic measurement of gross radioactivity is being widely used as an indicator of the satisfactory quality of community water systems with respect to radioactivity. Americium-241 apparently is being used by an increasing number of laboratories as an alternative gross alpha activity calibration standard in place of the recommended uranium. Higher alpha counting efficiencies obtained using 241Am result in gross alpha activity analysis differences of up to 100% when compared with duplicate sample analyses based on a natural uranium standard. Data presented in this report demonstrate that the use of 241Am as an alternative gross alpha calibration standard will, in effect, double the federally specified maximum contaminant level for gross dlpha activity in community water systems. Similar problems are associated with gross beta activity calibration standards but the effects are not as pronounced. Comparative counting efficiency data for 137Cs and 90Sr/90Y as gross beta activity calibration standards are given. Gross beta activity differences up to 25% may be obtained on duplicate analyses depending on the beta calibration standard used. If gross radioactivity measurements are to be useful indicators of water quality, strict adherence to standard procedures and acceptance of single calibration standards used for determining gross radioactivity concentrations in water are needed to achieve industry-wide comparabilteeded to achieve industry-wide comparabilty of results

317

Quality assurance programmes for radioactivity measurements in nuclear medicine  

International Nuclear Information System (INIS)

Accurate radioactivity measurements in the clinic are vital for ensuring that administered doses of radiopharmaceuticals are safe and effective. This accuracy is achieved both in the development phase of the drug and in its clinical application, when the instrumentation used is calibrated in a way that is traceable to national or international standards. For nearly 30 years the National Institute of Standards and Technology has maintained a dedicated programme aimed at developing and distributing reference sources and providing calibration services to the nuclear medicine community in North America. The result has been an overall improvement in measurement protocols by isotope producers and radiopharmaceutical manufacturers. The current emphasis of the programme is the development of secondary standards that can be used to enable a similar improvement in measurements in the clinic. The paper discusses the need for radioactivity standards in nuclear medicine and provides a review of this programme. (author)

318

Optical parameters Determination for absolute luminosity and total cross section measurements in ATLAS  

CERN Document Server

ALFA (Absolute Luminosity For ATLAS) aims at measuring the absolute luminosity for the ATLAS experiment with an incertitude down to 2-3 \\% and the total elastic cross section. The luminosity is related to the number of events, the highest the luminosity, the highest the number of events. This is, then, an important quantity for colliders like LHC (Large Hadron Collider). LHC is made of two beams circulating in two different beam pipes and colliding at four interaction points where the four physics experiments are located (ATLAS, CMS, ALICE, LHCb). ALFA detectors inserted into Roman Pots (RPs), have been placed around ATLAS at 240 m distance from the collision point (IP1) after six quadrupoles magnets and two dipoles defining the ALFA beam line which is part of the LHC ring.The detectors are made of scintillating optics fibers to catch elastic protons generated at IP1. These protons are tracked through the LHC magnets beam line which needs to be optimized in terms of optics parameters. We call high ? optics, ...

Cavalier, Sophie

319

Radioactive targets for neutron-induced cross section measurements  

Energy Technology Data Exchange (ETDEWEB)

Measurements using radioactive targets are important for the determination of key reaction path ways associated with the synthesis of the elements in nuclear astrophysics (sprocess), advanced fuel cycle initiative (transmutation of radioactive waste), and stockpile stewardship. High precision capture cross-section measurements are needed to interpret observations, predict elemental or isotopical ratios, and unobserved abundances. There are two new detector systems that are presently being commissioned at Los Alamos National Laboratory for very precise measurements of (n,{gamma}) and (n,f) cross-sections using small quantities of radioactive samples. DANCE (Detector for Advanced Neutron-Capture Experiments), a 4 {pi} gamma array made up of 160 BaF{sub 2} detectors, is designed to measure neutron capture cross-sections of unstable nuclei in the low-energy range (thermal to {approx}500 keV). The high granularity and high detection efficiency of DANCE, combined with the high TOF-neutron flux available at the Lujan Center provides a versatile tool for measuring many important cross section data using radioactive and isotopically enriched targets of about 1 milligram. Another powerful instrument is the Lead-slowing down spectrometer (LSDS), which will enable the measurement of neutron-induced fission cross-section of U-235m and other short-lived actinides in a energy range from 1-200 keV with sample sizes down to 10 nanograms. Due to the short half-life of the U-235m isomer (T{sub 1/2} = 26 minutes), the samples must be rapidly and repeatedly extracted from its {sup 239}Pu parent. Since {sup 239}Pu is itself highly fissile, the separation must not only be rapid, but must also be of very high purity (the Pu must be removed from the U with a decontamination factor >10{sup 12}). Once extracted and purified, the {sup 235m}U isomer would be electrodeposited on solar cells as a fission detector and placed within the LSDS for direct (n,f) cross section measurements. The production of radioactive targets of a few milligrams will be described as well as the containment for safe handling of these targets at the Lujan Center at LANSCE. To avoid any contamination, the targets are electrochemically fixed onto thin Ti foils and two foils are placed back to back to contain the radioactive material within. This target sandwich is placed in a cylinder made of aluminum with thin translucent windows made of Kapton. Actinides targets, such as {sup 234,235,236,238}U, {sup 237}Np, and {sup 239}Pu are prepared by electrodeposition or molecular plating techniques. Target thicknesses of 1-2 mg/cm{sup 2} with sizes of 1 cm{sup 2} or more have been made. Other targets will be fabricated from separation of irradiated isotopically enriched targets, such as {sup 155}Eu from {sup 154}Sm,{sup 171}Tm from {sup 170}Er, and {sup 147}Pm from {sup 146}Nd, which has been irradiated in the high flux reactor at ILL, Grenoble. A radioactive sample isotope separator (RSIS) is in the process of being commissioned for the preparation of other radioactive targets. A brief summary of these experiments and the radioactive target preparation technique will be given.

Kronenberg, A. (Andreas); Bond, E. M. (Evelyn M.); Glover, S. E. (Samuel E.); Rundberg, R. S. (Robert S.); Vieira, D. J. (David J.); Esch, E. I. (Ernst-Ingo); Reifarth, R. (Rene); Ullmann, J. L. (John L.); Haight, Robert C.; Rochmann, D. (Dimitri)

2004-01-01

320

Design of automatic control and measurement software for radioactive aerosol continuity monitor  

International Nuclear Information System (INIS)

The radioactive aerosol continuity measurement is very important for the development of nuclear industry, and it is the major method to measure and find out the leakage of radioactive material. Radioactive aerosol continuity monitor is the advanced method for the radioactive aerosol continuity measurement. With the development of nuclear industry and nuclear power station, it is necessary to design and automatic continuity measurement device. Because of this reason, the authors developed the first unit of radioactive aerosol continuity monitor and adopted the ministry appraisal. The design idea and method of automatic control and measurement for radioactive aerosol continuity monitor are discussed

321

Quality assurance programmes for radioactivity measurements in nuclear medicine  

International Nuclear Information System (INIS)

The accuracy of the estimation of dose delivered to patients receiving radiopharmaceutical therapy is vitally linked to the accuracy of measurements of the amount of radioactivity contained in the drug. This is due primarily to the fact that most Monte Carlo codes currently in use express the calculated dose in terms of a dose rate per unit activity. In order to reconcile experimental (or administered) dose rates and calculated (or intended) doses, the activity must be known as accurately as possible. Moreover, the consistency of dose estimates among a group of sites participating in clinical trials can only be ensured when the activity measurements are referenced to national or international standards. The Radioactivity Group of the National Institute of Standards and Technology (NIST) has an extremely active program aimed at ensuring good radioactivity measurements at all levels of nuclear medicine practice in North America. This talk gives an overview of this program and will conclude with a discussion of how it can be used as a model for an international effort in measurement quality assurance for nuclear medicine and radiopharmacy

322

Our experience of blood flow measurements using radioactive tracers  

International Nuclear Information System (INIS)

A critical study of blood flow measuring methods is proposed. After a review of the various diffusible and non-diffusible radioactive tracers and the corresponding detector systems, the principles which allow to measure blood flow from the data so obtained, are studied. There is a different principle of flow measurement for each type of tracer. The theory of flow measurement using non-diffusible tracers (human serum albumin labelled with 131I or sup(99m)Tc, 113In-labelled siderophiline) and its application to cardiac flow measurement are described first. Then the theory of flow measurement using diffusible tracers (133Xe, 85Kr) and its application to measurement of blood flow through tissues (muscles and kidney particularly) are described. A personal experience of this various flow measurements is reported. The results obtained, the difficulties encountered and the improvments proposed are developed

323

Photoionization quantometer for absolute intensity measurements of vacuum ultraviolet and soft x-ray radiation from laser plasma  

Science.gov (United States)

Design and parameters of the photoionization quantometer are given. It is a combination of photoionization chamber with time-of-flight mass spectrometer. The quantometer is an absolute detector of radiation in the wavelength interval (100-0.1 nm) due to the fact that photoionization and electron-impact ionization cross sections of gases are used for absolute measurements. The quantometer is suitable for measurements of the number of photons in radiation pulses. The minimum number of photons detectable for a single pulse increases from 106 cm-2 puls-1 at 100 nm up to 1011 cm-2 puls-1 for 0.1 nm. The quantometer has been used for vacuum ultraviolet and soft x-ray radiation measurements in the laser plasma experiment. An improved variant of the quantometer is presented which provides the absolute measurements of soft x-ray radiation for laser plasma having continuous spectrum. The inaccuracy of measurements does not exceed 25% for soft x ray.

Bobashev, S. V.; Shmaenok, L. A.

1981-01-01

324

Photoionization quantometer for absolute intensity measurements of vacuum ultraviolet and soft x-ray radiation from laser plasma  

International Nuclear Information System (INIS)

Design and parameters of the photoionization quantometer are given. It is a combination of photoionization chamber with time-of-flight mass spectrometer. The quantometer is an absolute detector of radiation in the wavelength interval (100--0.1 nm) due to the fact that photoionization and electron-impact ionization cross sections of gases are used for absolute measurements. The quantometer is suitable for measurements of the number of photons in radiation pulses. The minimum number of photons detectable for a single pulse increases from 106 cm-2 puls-1 at 100 nm up to 1011 cm-2 puls-1 for 0.1 nm. The quantometer has been used for vacuum ultraviolet and soft x-ray radiation measurements in the laser plasma experiment. An improved variant of the quantometer is presented which provides the absolute measurements of soft x-ray radiation for laser plasma having continuous spectrum. The inaccuracy of measurements does not exceed 25% for soft x ray

325

Absolute measurement of the activity of sup 2 sup 2 sup 2 Rn using a proportional counter  

CERN Document Server

A measuring set-up comprising a proportional counter of calculable sup 2 sup 2 sup 2 Rn efficiency and quantifiable active volume (delta sub V <0.1%) is described. On account of the special design of the end caps, the counter is suitable for absolute activity measurements on gaseous radiation sources. The sup 2 sup 2 sup 2 Rn efficiency is determined by computer simulation of the measured alpha-spectra. The procedures necessary for absolute measurements by means of the counter are described, and the suitability of the counter for absolute measurements of the sup 2 sup 2 sup 2 Rn activity is proved by experiments. Thus, a new method for the realization of the unit of activity of sup 2 sup 2 sup 2 Rn is obtained, which is independent of the unit of activity of sup 2 sup 2 sup 6 Ra.

Busch, I; Keyser, U

2002-01-01

326

Renewal of centralized radioactivity measurement system for radiation control  

International Nuclear Information System (INIS)

The centralized radioactivity measurement system has been used to carry out intensively measurements of a large number and variety of samples that are necessary for the control of radioactivity in the facilities of the JAERI Tokai Establishment and its environment. The operation of the system started in 1981, and presently the system processes more than 20,000 samples a year. However, the computers of the system have aged so much that the manufacturer's support and stable operation are no longer sure. Therefore, we renewed and restructured the computer system in 2003. A client-server system was adopted in the new system. The information of samples can be registered through the intranet. The clients can also confirm the progress of processing of their samples and browse the analytical results from their own computers. The renewed system can provide some convenience functions to the clients. (author)

327

DANCE device for measurement of (n, ?) reactions on radioactive species  

International Nuclear Information System (INIS)

DANCE (Device for Advanced Neutron Capture Experiments) is a 4? 162 element BaF2 array under development at Los Alamos National Laboratory. It is designed to provide high granularity, fast timing and high photon detection efficiency. It will be located at the Los Alamos Neutron Scattering Center where neutrons are produced using 800 MeV proton induced spallation reactions on heavy element production targets. Using the pulsed high neutron fluence available at this facility combined with time of flight techniques it will be possible to make neutron capture measurements in the neutron energy range from eV to 100's keV on rate and radioactive target material at the milligram and below level. These measurements will provide critically needed data for the interpretation of the astrophysical s-process 'branching point' nuclei as well as information for reactions needed in understanding transmutation processes of radioactive species. (author)

328

Measurement of D0??l?(Kl?) Form Factors and Absolute Branching Fractions  

International Nuclear Information System (INIS)

Using a 282 fb-1 data sample collected by the Belle experiment at the KEKB e+e- collider, we study D0 decays to K-l+? and ?-l+? final states. The D0 flavor and momentum are tagged through a full reconstruction of the recoiling charm meson and additional mesons from fragmentation. The reconstruction method provides very good resolution in neutrino momentum and in q2=(pl+p?)2. Normalizing to the total number of D0 tags, we measure the absolute branching fractions to be B(D0?Kl?)=(3.45±0.07stat±0.20syst)% and B(D0??l?)=(0.255±0.019stat±0.016syst)% and the semileptonic form factors (within the modified pole model) f+K(0)=0.695±0.007stat±0.022syst and f+?(0)=0.624±0.020stat±0.030syst

329

Measurement of the Absolute Branching Fraction of D^0 to K^- \\pi^+  

Energy Technology Data Exchange (ETDEWEB)

The authors measure the absolute branching fraction for D{sup 0} {yields} K{sup -} {pi}{sup +} using partial reconstruction of {bar B}{sup 0} {yields} D*{sup +} X {ell}{sup -} {bar {nu}}{sub {ell}} decays. Only the charged lepton and the soft pion from the decay D*{sup +} {yields} D{sup 0} {pi}{sup +} are used. Based on a data sample of 230 million B{bar B} pairs collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC, they obtain {Beta}(D{sup 0} {yields} K{sup -} {pi}{sup +}) = (4.025 {+-} 0.038 {+-} 0.098)%, where the first error is statistical and the second error is systematic.

Godang, Romulus

2006-12-06

330

Particle energy absolute calibration by measuring frequency of polarized electron spin procession on the VEPP-4  

International Nuclear Information System (INIS)

The method of absolute energy calibration of the VEPP-4 storage ring based on resonance depolarization of a polarized beam which is used for determining the spin precession frequency of polarized protons is described. The resonance effect on the beam is caused by an electromagnetic field. When the spin precession frequency coincides with the field frequency the beam is depolarized. The depolarization phenomenon is detected by measuring changes in the counting rate of particles departing the beam due to the effect of internal scattering which cross section depends on the degree of beam polarization. The resonance depolarization method is used for calibrating beam energy in the VEPP-4 with an accuracy not worse than 5x10-5

331

Absolute density measurement of SD radicals in a molecular beam at the quantum-noise-limit  

CERN Document Server

The absolute density of SD radicals in a molecular beam has been measured down to $(1.1\\pm0.1)\\times10^5$ cm$^{-3}$ in a modestly specified apparatus that uses a cross-correlated combination of cavity ring-down and laser-induced fluorescence detection. Such a density corresponds to $215\\pm21$ molecules in the probe volume at any given time. The quantum-noise-limited noise-equivalent absorption sensitivity of the apparatus was found to be $(3.5\\pm0.3)\\times10^{-11}$ cm$^{-1}$ Hz$^{-1/2}$ based on a 200 s acquisition time at 10 Hz, therefore competing favourably with more sophisticated techniques.

Mizouri, Arin; Eardley, Jack S; Nahler, N Hendrik; Wrede, Eckart; Carty, David

2013-01-01

332

Absolute Polarization Measurements at RHIC in the Coulomb Nuclear Interference Region  

CERN Document Server

The Relativistic Heavy Ion Collider at Brookhaven National Laboratory provides polarized proton beams for the investigation of the nucleon spin structure. For polarimetry, carbon-proton and proton-proton scattering is used in the Coulomb nuclear interference region at small momentum transfer ($-t$). Fast polarization measurements of each beam are carried out with carbon fiber targets at several times during an accelerator store. A polarized hydrogen gas jet target is needed for absolute normalization over multiple stores, while the target polarization is constantly monitored in a Breit-Rabi polarimeter. In 2005, the jet polarimeter has been used with both RHIC beams. We present results from the jet polarimeter including a detailed analysis of background contributions to asymmetries and to the beam polarization.

Eyser, K O; Bravar, A; Bunce, G; Dhawan, S; Gill, R; Haeberli, W; Huang, H; Jinnouchi, O; Makdisi, Y; Nakagawa, I; Nass, A; Okada, H; Stephenson, E; Svirida, D; Wise, T; Wood, J; Zelenski, A

2007-01-01

333

Measurement of the Absolute Proton and Helium Flux at the Top of the Atmosphere using IMAX  

Science.gov (United States)

The balloon-borne experiment IMAX launched from Lynn Lake, Canada in 1992 has been used to measure the cosmic ray proton and helium spectra from 0.2 GV to approximately 100 GV. The IMAX apparatus was designed to search for antiprotons and light isotopes using a superconducting magnet spectrometer with ancillary scintillators, time-of-flight, and aerogel cherenkov detectors. High resolution drift chambers and MWPCs were used as the tracking devices. Using redundant detectors, an extensive examination of the instrument efficiency was carried out. We present the absolute spectra of protons and helium corrected to the top of the atmosphere. The IMAX experiment was supported by NASA: RTOP 353-87-02 (GSFC), grants NAGW-1919 (Caltech) and NAGW-1418 (NMSU), and in Germany by the DFG and the BMFT. ^1 present address Max-Planck-Institut für Extraterrestrische Physik

Menn, W.; Hof, M.; Reimer, O.; Simon, M.; Barbier, L. M.; Christian, E. R.; Krombel, K. E.; Mitchell, J. W.; Ormes, J. F.; Streitmatter, R. E.; Davis, A. J.; Labrador, A. W.; Mewaldt, R. A.; Schindler, S. M.; Golden, R. L.; Stochaj, S. J.; Webber, W. R.; Rasmussen, I. L.

1996-05-01

334

Radiation protection measures for the handling of unsealed radioactive materials  

International Nuclear Information System (INIS)

The radiation protective medical measures are described which are required after contamination by radioactive materials or their incorporation. In the case of skin contamination, penetration by diffusion is explained and the maximum permissible value with regard to the various types of radiation is given. A detailed description of the decontamination measures including the necessary equipment follows. Indications for the treatment of injuries are given. In addition, incorporation due to inhalation, ingestion with intake through the skin are described, direct and indirect incorporation detection are explained, and the therapeutical possibilities and measures are gone into. (ORU/LH)

335

Precision mass measurements of radioactive nuclei at JYFLTRAP  

CERN Document Server

The Penning trap mass spectrometer JYFLTRAP was used to measure the atomic masses of radioactive nuclei with an uncertainty better than 10 keV. The atomic masses of the neutron-deficient nuclei around the N = Z line were measured to improve the understanding of the rp-process path and the SbSnTe cycle. Furthermore, the masses of the neutron-rich gallium (Z = 31) to palladium (Z = 46) nuclei have been measured. The physics impacts on the nuclear structure and the r-process paths are reviewed. A better understanding of the nuclear deformation is presented by studying the pairing energy around A = 100.

Rahaman, S; Eronen, T; Hager, U; Hakala, J; Jokinen, A; Kankainen, A; Moore, I D; Pentillä, H; Rinta-Antila, S; Rissanen, J; Saastamoinen, A; Sonoda, T; Weber, C; Äystö, J

2007-01-01

336

National network of environment radioactivity measurements. Press kit  

International Nuclear Information System (INIS)

This document first presents the objectives, challenges, context, operation and actors of the French national network of environment radioactivity measurements. It discusses the reasons for these measurements, the way they are performed, who perform them and how they are transmitted to the national network. It describes the quality policy for these measurements, and how this network is at the service of authorities, experts and population. It outlines the originality of the French approach within the European Union, and how this network takes the population expectations and their evolution into account

337

Traceability of measurements of radioactivity and of amount of substance  

International Nuclear Information System (INIS)

Comparability of measurement results in space and time are highly desirable to observe whether differences are real, whether concordance of results is real and whether trends over time of the quantity measured, are significant.The metrological way to achieve this, is to make results 'traceable' to a common 'stated reference' (definition in the Vocabulaire International de Metrologie - VIM). This 'stated reference' should be (the value of) the relevant SI unit wherever and whenever possible. The latest traceability concepts for results of measurements of radioactivity and amount of substance are presented and critically compared for their similarity. Transparent and simple pictures of traceability chains are given, respecting the VIM definition

338

Measurements of radioactive and xenobiotic substances in the biosphere in the Netherlands 1983  

International Nuclear Information System (INIS)

In this annual report the results and conclusions are given of measurements of radioactive and xenobiotic substances in the biosphere of the Netherlands. The measurements are coordinated by the Coordinating Committee for the Monitoring of Radioactive and Xenobiotic Substances (CCRX)

339

Absolute measurements of the fast neutron capture cross section of 115In  

International Nuclear Information System (INIS)

The 115In(n,#betta#)/sup 116m1/In cross section has been absolutely determined at neutron energies of 23, 265 and 964 keV. These energies are the median neutron energies of the three photo-neutron sources. Sb-Be, Na-CD2 and Na-Be, utilized in this work. The measurements are independent of other cross section data except for corrections amounting to less than 10%. Independent determinations of the reaction rate, detector efficiency, neutron source strength, scalar flux and target masses were performed. Reaction rates were determined by beta counting of the /sup 116ml/In decay activity using a 4? gas flow proportional counter. Detector efficiency was measured using 4?#betta#-#betta# coincidence counting techniques and the foil absorber method of efficiency extrapolation for correction of complex decay scheme effects. Photoneutron source emission rates were determined by intercomparison with the NBS-II calibrated 252Cf spontaneous fission neutron source in the University of Michigan Manganese Bath. The normalized scalar flux was calculated from the neutron emission angular distribution results of the Monte Carlo computer program used to model neutron and gamma transport in the source. Target mass determinations were made with a microbalance. Correction factors were applied for competing reaction activities, neutron scattering from experiment components, room-return induced activities, spectral effects in the manganese bath and the neutron energy spectra of the photoneutron sources. Experimental cross section results were normalized to the source median energy using energy spectra d cross section shape data. The absolute cross sections obtained for the 115In(n,#betta#)/sup 116ml/In reaction were 588 +- 12, 196 +- 4 and 200 +- 3 millibarns at 23, 265 and 964 keV, respectively

340

Measurement of performances of aerosol type radioactive contamination monitors  

International Nuclear Information System (INIS)

The EPICEA laboratory (Laboratoire d'Essais Physiques des Instruments de Mesure de la Contamination de l'Eau de de l'Air), which belongs to the Institut de Protection et de Surete Nucleaire (IPSN), was created to carry out type tests on atmospheric contamination monitors under the conditions recommended by the International Electrotechnical Commission (IEC). These tests are carried out at the request of users, scientific or industrial manufacturers, either French or foreign, to define the performance of a given aerosol radioactive contamination monitor in order to obtain type approval for the monitor by the IPSN Centre Technique d'Homologation de l'Instrumentation de Radioprotection (CTHIR). Tests can also be used for defining prototypes manufactured by the industry. There are two types of tests: (1) Static tests are performed with solid standard radioactive sources. Six different tests are used to verify the performances of the monitors and to measure their detection efficiency for solid sources. (2) Dynamic tests are performed on the ICARE bench. This bench, continuously generating natural and artificial radioactive aerosols, calibrated for size and activity, enables the true performances of the radioactive aerosols monitors to be defined under normal operating conditions. The true measurement efficiency is obtained by sampling and measuring, in real time, the activity of aerosols labelled with 239Pu and/or 137Cs. The influence of the natural a37Cs. The influence of the natural activity upon the artificial activity measurement channels is determined by aerosols bearing radon decay products whose concentration and attached fraction can be adjusted. Knowledge of the factor of influence of the natural activity and the type of treatment (algorithm) used on this monitor makes it possible to calculate the monitor detection threshold under normal operating conditions. The dynamic test procedures described in this document have been adopted as an international standard by the IEC in 1995. (author)

341

Measurements of radioactive dusts in high altitude air  

International Nuclear Information System (INIS)

The radioactivities of the airborne dusts were measured in samples collected by an aircraft of the Japan Air Self-Defence Force in high altitude during the period between April 1997 and March 1998. The data of the gross beta activities show that there is no appreciable difference from the activity levels of the year before and seasonal variations are becoming not so clear. (author)

342

Measurements of environmental radiations and radioactivities in Toki, (3)  

International Nuclear Information System (INIS)

In this issue two reports are given from the 1983 IPP-Toki collaborational works of surveying environmental radiations and radioactivities over the Toki area. One of them is concerned with the TLD observations of radiation levels by a team of local school teachers, and the other shows the results of sample measurements due to gamma- and alpha- spectrometry by the IPP group. In addition, a map of background radiation levels in Japan is included for the reference use. (author)

343

Determination and control measurements of coincidence devices used for activity measurements by absolute method  

International Nuclear Information System (INIS)

Description of the method of performing determination and control measurements is given which are done on the measuring device with 4?-proportional counter under elevated pressure. The device is working according to the coincidence method. Accuracy of this method greatly depends on determination of electronic parameters and different correction facters. Control measurements are done for testing the state of the counter and electronic circuit of the device for determination of the energy equivalent for descrimination level of 4?-proportional counter; for determination of the resolution ability of the counter, for determination of first and coincidence time. Determination measurements are done for testing a tuning of the device for measurement of the given nuclide and include a turing of ?-chanel; measurement of activity of ?-emitter with continious spectrum; measurement of activity of nuclides with discrete spectrum; turing of ?-chanel; turing of the coincidence circuit. The method of plotting of the curve for data extrapolation is given

344

Absolute calibration method for laser megajoule neutron yield measurement by activation diagnostics.  

Science.gov (United States)

The laser megajoule (LMJ) and the National Ignition Facility (NIF) plan to demonstrate thermonuclear ignition using inertial confinement fusion (ICF). The neutron yield is one of the most important parameters to characterize ICF experiment performance. For decades, the activation diagnostic was chosen as a reference at ICF facilities and is now planned to be the first nuclear diagnostic on LMJ, measuring both 2.45 MeV and 14.1 MeV neutron yields. Challenges for the activation diagnostic development are absolute calibration, accuracy, range requirement, and harsh environment. At this time, copper and zirconium material are identified for 14.1 MeV neutron yield measurement and indium material for 2.45 MeV neutrons. A series of calibrations were performed at Commissariat a? l'Energie Atomique (CEA) on a Van de Graff facility to determine activation diagnostics efficiencies and to compare them with results from calculations. The CEA copper activation diagnostic was tested on the OMEGA facility during DT implosion. Experiments showed that CEA and Laboratory for Laser Energetics (LLE) diagnostics agree to better than 1% on the neutron yield measurement, with an independent calibration for each system. Also, experimental sensitivities are in good agreement with simulations and allow us to scale activation diagnostics for the LMJ measurement range. PMID:21806179

Landoas, Olivier; Glebov, Vladimir Yu; Rossé, Bertrand; Briat, Michelle; Disdier, Laurent; Sangster, Thomas C; Duffy, Tim; Marmouget, Jean Gabriel; Varignon, Cyril; Ledoux, Xavier; Caillaud, Tony; Thfoin, Isabelle; Bourgade, Jean-Luc

2011-07-01

345

Absolute calibration method for laser megajoule neutron yield measurement by activation diagnostics  

International Nuclear Information System (INIS)

The laser megajoule (LMJ) and the National Ignition Facility (NIF) plan to demonstrate thermonuclear ignition using inertial confinement fusion (ICF). The neutron yield is one of the most important parameters to characterize ICF experiment performance. For decades, the activation diagnostic was chosen as a reference at ICF facilities and is now planned to be the first nuclear diagnostic on LMJ, measuring both 2.45 MeV and 14.1 MeV neutron yields. Challenges for the activation diagnostic development are absolute calibration, accuracy, range requirement, and harsh environment. At this time, copper and zirconium material are identified for 14.1 MeV neutron yield measurement and indium material for 2.45 MeV neutrons. A series of calibrations were performed at Commissariat a l'Energie Atomique (CEA) on a Van de Graff facility to determine activation diagnostics efficiencies and to compare them with results from calculations. The CEA copper activation diagnostic was tested on the OMEGA facility during DT implosion. Experiments showed that CEA and Laboratory for Laser Energetics (LLE) diagnostics agree to better than 1% on the neutron yield measurement, with an independent calibration for each system. Also, experimental sensitivities are in good agreement with simulations and allow us to scale activation diagnostics for the LMJ measurement range.

346

Absolute calibration method for laser megajoule neutron yield measurement by activation diagnostics  

Energy Technology Data Exchange (ETDEWEB)

The laser megajoule (LMJ) and the National Ignition Facility (NIF) plan to demonstrate thermonuclear ignition using inertial confinement fusion (ICF). The neutron yield is one of the most important parameters to characterize ICF experiment performance. For decades, the activation diagnostic was chosen as a reference at ICF facilities and is now planned to be the first nuclear diagnostic on LMJ, measuring both 2.45 MeV and 14.1 MeV neutron yields. Challenges for the activation diagnostic development are absolute calibration, accuracy, range requirement, and harsh environment. At this time, copper and zirconium material are identified for 14.1 MeV neutron yield measurement and indium material for 2.45 MeV neutrons. A series of calibrations were performed at Commissariat a l'Energie Atomique (CEA) on a Van de Graff facility to determine activation diagnostics efficiencies and to compare them with results from calculations. The CEA copper activation diagnostic was tested on the OMEGA facility during DT implosion. Experiments showed that CEA and Laboratory for Laser Energetics (LLE) diagnostics agree to better than 1% on the neutron yield measurement, with an independent calibration for each system. Also, experimental sensitivities are in good agreement with simulations and allow us to scale activation diagnostics for the LMJ measurement range.

Landoas, Olivier; Rosse, Bertrand; Briat, Michelle; Marmouget, Jean Gabriel; Varignon, Cyril; Ledoux, Xavier; Caillaud, Tony; Thfoin, Isabelle; Bourgade, Jean-Luc [CEA, DAM, DIF, F-91297 Arpajon (France); Glebov, Vladimir Yu; Sangster, Thomas C.; Duffy, Tim [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Disdier, Laurent [CEA, LIST, F-91191 Gif-sur-Yvette (France)

2011-07-15

347

Absolute production rate measurements of nitric oxide by an atmospheric pressure plasma jet (APPJ)  

International Nuclear Information System (INIS)

Tunable diode laser absorption spectroscopy (TDLAS) has been applied to measure the absolute production rate of NO molecules in the gas phase of an atmospheric pressure plasma jet (APPJ) operating at rf (13.56 MHz) in argon with small (up to 1%) admixtures of air. The resulting NO production rates were found to be in the range (0.1-80) x 10-3 sccm or (0.05-35) x 1018 molecules s-1 depending on the experimental conditions. Maximum rates were obtained at 0.2% air. For TDLAS measurements the APPJ was arranged inside an astigmatic multi-pass cell of Herriott type with 100 m absorption length. The insertion into a closed volume differs slightly from the normal, open operation with the jet propagating freely into air. Therefore, the measuring results are compared with optical emission of the open jet to verify equivalent experimental conditions. The dependence of the optical emission of NO (237 nm) on power and gas mixture has been measured. The similar shape of the dependence of absorption and emission signals gives evidence that the comparability of experimental conditions is sufficiently satisfied. It is concluded that the NO production rate of the APPJ in ambient air can be characterized using TDLAS and provides reliable results in spite of differing experimental conditions due to the set-up.

348

New method for absolute measurement of neutron flux in reactors operated at high power levels  

International Nuclear Information System (INIS)

The objective of this thesis is to develop and study two methods of neutron measurements in nuclear reactors - new methods for measuring fast neutron fluxes, and Li6 semiconductor neutron spectrometer. It contains four chapters: Chapter I, Introduction covers the explanation of the need for neutron measurements in the reactor, and critical consideration of the existing methods for fast neutron flux measurements as well as methods for measuring the fast neutron spectra. Chapter II describes theoretical basis of semiconductor counters operation and their most important properties. Chapter III includes the description of the method developed by the author, long-tube method, and the results obtained by applying this method with the special emphasis on absolute measurements of fast neutron flux. Advantages and limitations of this method are discussed at the end of this chapter. Chapter IV contains intercomparison of the existing semiconductor spectrometers and emphasis of their positive and negative properties. A critical analysis of the results obtained by Li6 spectrometer with flat geometry in included. A new type of Li6 semiconductor spectrometer is described. Its properties are experimentally determined and it was compared to the classical Li6 spectrometer. Most of the experiments were done in the Physics Laboratory and at RA and RB reactors in the 'Boris Kidric' Institute of Nuclear Sciences in Vinca, and some at reactor in Sciences in Vinca, and some at reactor in McMaster University, Hamilton, Canada. Experiments concerned with registering particles scattering were done at the Lockheed research reactor during fall 1963 in Belgrade. Neutron fluxes and spectra were measured by semiconductor counters improved and adapted for neutronic measurements by the author

349

Direct comparison of a Ca+ single-ion clock against a Sr lattice clock to verify the absolute frequency measurement.  

Science.gov (United States)

Optical frequency comparison of the (40)Ca(+) clock transition ?(Ca)((2)S(1/2-)(2D(5/2), 729 nm) against the (87)Sr optical lattice clock transition ?(Sr) ((1)S(0)-(3)P(0), 698 nm) has resulted in a frequency ratio ?(Ca) / ?(Sr) = 0.957 631 202 358 049 9(2 3). The rapid nature of optical comparison allowed the statistical uncertainty of frequency ratio ?(Ca) / ?(Sr) to reach 1 × 10(-15) in 1000s and yielded a value consistent with that calculated from separate absolute frequency measurements of ?(Ca) using the International Atomic Time (TAI) link. The total uncertainty of the frequency ratio using optical comparison (free from microwave link uncertainties) is smaller than that obtained using absolute frequency measurement, demonstrating the advantage of optical frequency evaluation. We note that the absolute frequency of (40)Ca(+) we measure deviates from other published values by more than three times our measurement uncertainty. PMID:23037353

Matsubara, Kensuke; Hachisu, Hidekazu; Li, Ying; Nagano, Shigeo; Locke, Clayton; Nogami, Asahiko; Kajita, Masatoshi; Hayasaka, Kazuhiro; Ido, Tetsuya; Hosokawa, Mizuhiko

2012-09-24

350

Absolute frequency measurements of 85Rb nF7/2 Rydberg states using purely optical detection  

OpenAIRE

A three-step laser excitation scheme is used to make absolute frequency measurements of highly excited nF7/2 Rydberg states in 85Rb for principal quantum numbers n=33-100. This work demonstrates the first absolute frequency measurements of rubidium Rydberg levels using a purely optical detection scheme. The Rydberg states are excited in a heated Rb vapour cell and Doppler free signals are detected via purely optical means. All of the frequency measurements are made using a w...

Johnson, L. A. M.; Majeed, H. O.; Sanguinetti, B.; Becker, Th; Varcoe, B. T. H.

2010-01-01

351

Femtosecond frequency comb measurement of absolute frequencies and hyperfine coupling constants in cesium vapor  

Science.gov (United States)

We report measurements of absolute transition frequencies and hyperfine coupling constants for the 8S1/2, 9S1/2, 7D3/2, and 7D5/2 states in Cs133 vapor. The stepwise excitation through either the 6P1/2 or 6P3/2 intermediate state is performed directly with broadband laser light from a stabilized femtosecond laser optical-frequency comb. The laser beam is split, counterpropagated, and focused into a room-temperature Cs vapor cell. The repetition rate of the frequency comb is scanned and we detect the fluorescence on the 7P1/2,3/2?6S1/2 branches of the decay of the excited states. The excitations to the different states are isolated by the introduction of narrow-bandwidth interference filters in the laser beam paths. Using a nonlinear least-squares method we find measurements of transition frequencies and hyperfine coupling constants that are in agreement with other recent measurements for the 8S state and provide improvement by 2 orders of magnitude over previously published results for the 9S and 7D states.

Stalnaker, Jason E.; Mbele, Vela; Gerginov, Vladislav; Fortier, Tara M.; Diddams, Scott A.; Hollberg, Leo; Tanner, Carol E.

2010-04-01

352

Femtosecond frequency comb measurement of absolute frequencies and hyperfine coupling constants in cesium vapor  

International Nuclear Information System (INIS)

We report measurements of absolute transition frequencies and hyperfine coupling constants for the 8S1/2, 9S1/2, 7D3/2, and 7D5/2 states in 133Cs vapor. The stepwise excitation through either the 6P1/2 or 6P3/2 intermediate state is performed directly with broadband laser light from a stabilized femtosecond laser optical-frequency comb. The laser beam is split, counterpropagated, and focused into a room-temperature Cs vapor cell. The repetition rate of the frequency comb is scanned and we detect the fluorescence on the 7P1/2,3/2?6S1/2 branches of the decay of the excited states. The excitations to the different states are isolated by the introduction of narrow-bandwidth interference filters in the laser beam paths. Using a nonlinear least-squares method we find measurements of transition frequencies and hyperfine coupling constants that are in agreement with other recent measurements for the 8S state and provide improvement by 2 orders of magnitude over previously published results for the 9S and 7D states.

353

Femtosecond frequency comb measurement of absolute frequencies and hyperfine coupling constants in cesium vapor  

CERN Document Server

We report measurements of absolute transition frequencies and hyperfine coupling constants for the 8S_{1/2}, 9S_{1/2}, 7D_{3/2}, and 7D_{5/2} states in ^{133}Cs vapor. The stepwise excitation through either the 6P_{1/2} or 6P_{3/2} intermediate state is performed directly with broadband laser light from a stabilized femtosecond laser optical-frequency comb. The laser beam is split, counter-propagated and focused into a room-temperature Cs vapor cell. The repetition rate of the frequency comb is scanned and we detect the fluorescence on the 7P_{1/2,3/2} -> 6S_{1/2} branches of the decay of the excited states. The excitations to the different states are isolated by the introduction of narrow-bandwidth interference filters in the laser beam paths. Using a nonlinear least-squares method we find measurements of transition frequencies and hyperfine coupling constants that are in agreement with other recent measurements for the 8S state and provide improvement by two orders of magnitude over previously published res...

Stalnaker, Jason E; Gerginov, Vladislav; Fortier, Tara M; Diddams, Scott A; Hollberg, Leo; Tanner, Carol E

2010-01-01

354

Luminosity measurement method for the LHC: Event selection and absolute luminosity determination  

International Nuclear Information System (INIS)

In our earlier papers Krasny et al. [1,2] have proposed a new luminosity measurement method which uses lepton pairs produced in peripheral collisions of the LHC beam particles, and identified the requirements for a new, specialized luminosity detector which is indispensable for their efficient on-line selection. In this paper we use the base-line detector model, with no precise timing capabilities, to evaluate the statistical and systematic accuracy of the method. We propose the complete event selection procedure and demonstrate that it allows to collect a sufficiently large sample of e+e? pairs to achieve a better than 1% statistical accuracy of the luminosity measurement over less than one-month-long running time intervals. We argue that the absolute luminosity measurement systematic errors can be kept below 1%. The proposed method can be directly applied to the LHC running periods for which the machine instantaneous luminosity does not exceed the L=1033s?1cm?2 value. Two ways extending the method to the large pile-up periods corresponding to higher instantaneous luminosities are proposed

355

Effect of size and composition of the body on absolute measurement of calcium in vivo  

International Nuclear Information System (INIS)

The effect of size and composition of the body on the measurement of total calcium in absolute units by neutron activation analysis is described. The neutron beam, produced from a cyclotron, was of mean energy 7.5 MeV. Counting of the activities induced in a patient was carried out with a multidetector whole body counter. Calibration of the system was achieved by using two phantoms of different sizes containing known quantities of calcium. The dimensions of various phantom sections were varied to determine the effect on efficiency of activation, an approximately linear relationship with body thickness being found. The influence of body habitus on counting efficiency was assessed by counting different patients who had been given known quantities of 42K. The effects of (a) the non-uniform distribution of calcium and (b) the variation in density of different tissues on both activation and counting efficiency are discussed. It is estimated that the 68% confidence limits on the measurement of 49Ca count rate per unit neutron fluence is +- 3.0% and on the measurement of calcium in grams +- 8.2%. (author)

356

Cryogenic Current Comparator for Absolute Measurement of the Dark Current of the Superconducting Cavities for Tesla  

CERN Document Server

A newly high performance SQUID based measurement system for detecting dark currents, generated by superconducting cavities for TESLA is proposed. It makes use of the Cryogenic Current Comparator principle and senses dark currents in the nA range with a small signal bandwidth of 70 kHz. To reach the maximum possible energy in the TESLA project is a strong motivation to push the gradients of the superconducting cavities closer to the physical limit of 50 MV/m. The field emission of electrons (the so called dark current) of the superconducting cavities at strong fields may limit the maximum gradient. The absolute measurement of the dark current in correlation with the gradient will give a proper value to compare and classify the cavities. This contribution describes a Cryogenic Current Comparator (CCC) as an excellent and useful tool for this purpose. The most important component of the CCC is a high performance DC SQUID system which is able to measure extremely low magnetic fields, e.g. caused by the extracted ...

Knaack, K; Wittenburg, K

2003-01-01

357

Absolute measurement of the effective nonlinearities of KTP and BBO crystals by optical parametric amplification.  

Science.gov (United States)

Absolute magnitudes of the effective nonlinearity, deff, were measured for seven KTP and six BBO crystals. The d(eff), were derived from the parametric gain of an 800-nm signal wave in the sample crystals when they were pumped by the frequency-doubled, spatially filtered light from an injectionseeded, Q-switched Nd:YAG laser. The KTP crystals, all type II phase matched with propagation in the X-Z plane, had d(eff) values ranging from 1.97 to 3.50 pm/V. Measurements of gain as a function of phase velocity mismatch indicate that two of the KTP crystals clearly contain multiple ferroelectric domains. For five type I phase-matched BBO crystals, d(eff) ranged from 1.76 to 1.83 pm/V, and a single type II phase-matched BBO crystal had a d(eff) of 1.56 pm/V. The uncertainty in our measurements of d(eff) values is ±5% for KTP and ±10% for BBO. PMID:21085331

Armstrong, D J; Alford, W J; Raymond, T D; Smith, A V

1996-04-20

358

Absolute single photoionization cross-section measurements of Se3+ and Se5+  

International Nuclear Information System (INIS)

Absolute single photoionization cross-section measurements of Se3+ and Se5+ ions were performed using monochromatized synchrotron radiation and the photo-ion merged-beams technique. Se3+ measurements were made at a photon energy resolution of 20 ± 3 meV from 41.90 to 54.56 eV, spanning the 2P1/2 ground state ionization threshold. Numerous autoionizing resonances arising from both the 2P1/2 ground state and 2P3/2 metastable state are identified using quantum defect analysis. For Se5+, measurements were made at a photon energy resolution of 60 ± 10 meV from 81 to 101 eV, spanning the 2S1/2 ground state ionization threshold, and at a photon energy resolution of 28 ± 3 meV from 100.175 to 106.675 eV in a region rich with autoionizing resonances. The direct ionization threshold of the Se5+ 2S1/2 ground state is experimentally determined to be 81.780 ± 0.010 eV. (paper)

359

Gamma spectrometric system for measuring low and medium radioactive samples  

International Nuclear Information System (INIS)

Measuring radioactive samples from environment and animal sub-products which usually have low radioactivity and a mixture of a radionuclides, requires the use of complex spectrometric systems. In our Department such a system was development, currently equipped with scintillation detector. All the electronic modules (High Voltage Supply, Pulse Amplifier, ADC) in the system are fully digitally controlled by the computer via a specialized interface and a special device driver, which is a resident program. The spectrum acquisition is performed in the background by the device driver. Spectrum processing (peak search, background subtraction, radionuclide identification, energy and efficiency calibration, activity and associated error calculation) is done by a special application which has a user friendly graphic interface and includes database and reporting facilities. The next year the system will be equipped with an automatic sample changer for large volume samples. We intend to provide the possibility to use also a HPGe detector. (authors)

360

Measurement of radioactivity in the sediments of Lake Biwa  

International Nuclear Information System (INIS)

Radioactivity in the bottom sediments of Lake Biwa (North Lake) was measured with a well-type HPGe gamma-ray spectrometer. Layered sediments were ascertained and dated with the 210Pb contents decreasing as depth. The distribution of 137Cs showed the downward migration of 137Cs. Elemental contents in the sediments and lake waters were measured by ICP(Inductively Coupled Plasma-Atomic Emission Spectroscopy)-AES, FLAAS(Flame Atomization Absorption Spectroscopy), and ICP-MS(Inductively Coupled Plasma-Mass Spectroscopy). Discussion on the results is given. (author)

361

Development of radioactive methods for direct measurement of steel machinability  

International Nuclear Information System (INIS)

A review of direct methods for measuring and evaluation of stability of cutting tools has been given. These methods using radioactive isotope techniques are being developed at Trybology Laboratory, Department of Mechanical Engineering, Kraguevets, and Radioisotope Laboratory, Boris Kidric Institute, Yugoslavia. Direct measuring of wear is being planned for tools used in cutting of alloys, steels and other metals, in order to determine machinability of various structural materials. The experimental method is generally used for the tools with the surface irradiated by proton and neutron particles in an accelerator. The tools of high-speed steel, and tungsten carbide, titanium carbide, etc. were investigated during cutting, milling, and drilling of metals

362

Radioactivity measurement of ?-nuclides by small solid angle method  

International Nuclear Information System (INIS)

Counting under a precise small solid angle is one of the oldest methods developed for the radioactivities measurement of ?-nuclides. The principle of solid angle counting is very simple and the accuracy is much better. The advantages of an equipment developed by the authors, in which a large area Au-Si surface barrier detector (450 mm2) is used, are introduced. Some comparisons on measurement results have been obtained with the gridded ionization chamber, and a national comparison result of 241Am which deviated from the average result is less than 0.2% are presented in detail

363

Functional requirements document for measuring emissions of airborne radioactive materials  

International Nuclear Information System (INIS)

This document states the functional requirements and procedures for systems making measurements of radioactive airborne emissions from facilities at the Hanford Site. The following issues are addressed in this document: Definition of the program objectives; Selection of the overall approach to collecting the samples; Sampling equipment design; Sampling equipment maintenance, and quality assurance issues. The intent of this document is to assist WHC in demonstrating a high quality of air emission measurements with verified system performance based on documented system design, testing, inspection, and maintenance

364

The Design of Absolute Power Measurement System of Zero Power Reactor Based on Reactor Noise Analysis Technology  

International Nuclear Information System (INIS)

The system carries out the Measurement of reactor kinetic parameters and absolute power of zero Power Reactor in the delayed critical state, using reactor noise analysis technology. Two ?-compensation ionization chambers are placed symmetrically close to the core. After being detected in the chambers, the reactor neutron noise signal shall be modulated and collected by measurement system. Then the noise signal shall be analysed by the software based on Labview to get cross-power spectral densities. The kinetic parameters are obtained from Nonlinear least-squares fitting of cross-power spectral densities. Absolute power of zero power reactor shall be obtained by algorithm. After field measurement, kinetic parameters and absolute power are identical with reactor operation parameters. (authors)

365

Radioactive Sources in Medicine: Impact of Additional Security Measures  

International Nuclear Information System (INIS)

For many years, medical centers and hospitals have utilized appropriate security measures to prevent theft or unauthorized use of radioactive materials. Recent anxiety about orphan sources and terrorism has heightened concern about diversion of radioactive sources for purposes of constructing a radiological dispersion device. Some medical centers and hospitals may have responded by conducting threat assessments and incorporating additional measures into their security plans, but uniform recommendations or regulations have not been promulgated by regulatory agencies. The International Atomic Energy Agency drafted interim guidance for the purpose of assisting member states in deciding what security measures should be taken for various radioactive sources. The recommendations are aimed at regulators, but suppliers and users also may find the recommendations to be helpful. The purpose of this paper is to describe threat assessments and additional security actions that were taken by one large and one medium-sized medical center and the impact these measures had on operations. Both medical centers possess blood bank irradiators, low-dose-rate therapy sources, and Mo-99/Tc-99m generators that are common to many health care organizations. Other medical devices that were evaluated include high-dose-rate after loaders, intravascular brachytherapy sources, a Co-60 stereotactic surgery unit, and self-shielded irradiators used in biomedical research. This paper will discuss the iml research. This paper will discuss the impact additional security has had on practices that utilize these sources, cost of various security alternatives, and the importance of a security culture in assuring the integrity of security measures without negatively impacting beneficial use of these sources. (Author) 10 refs

366

Low energy ? counts at the radioactivity measurement laboratory of Grenoble  

International Nuclear Information System (INIS)

Radioelements emitting ? low energy are very useful in biology specially in labelled compounds. The counting method with liquid scintillator is very often used. The radioactivity measurement laboratory of Grenoble uses for these measures a Tricarb-Packard. The samples to be counted are: tritiated water which is measured with a dioxane scintillator; animals textures which is measured with a dioxane scintillator; animals textures which contain 14C: these samples are dissolved in hyamine 10 X, then melted with a toluene scintillator, solid samples containing 14C or 45Ca (plant ashes); these samples are measured by suspension in scintillating mixtures. Gaseous samples 14CO2 are also counted, the gas is retained by hyamine, then mixed with a liquid scintillator. Counting of double labelled samples are also made 45Ca + 32P and 14C + 32P. The quenching corrections are made by internal standardization method, by channels ratio method or better by external standardization method. (author)

367

Weak Interaction Measurements with Optically Trapped Radioactive Atoms  

International Nuclear Information System (INIS)

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project is to apply the latest in magneto-optical and pure magnetic trapping technology to concentrate, cool, confine, and polarize radioactive atoms for precise electroweak interaction measurements. In particular, the authors have concentrated their efforts on the trapping of 82Rb for a parity-violating, beta-asymmetry measurement. Progress has been made in successfully trapping of up to 6 million 82Rb(t1/2=75s) atoms in a magneto-optical trap coupled to a mass separator. This represents a two order of magnitude improvement in the number trapped radioactive atoms over all previous work. They have also measured the atomic hyperfine structure of 82Rb and demonstrated the MOT-to-MOT transfer and accumulation of atoms in a second trap. Finally, they have constructed and tested a time-orbiting-potential magnetic trap that will serve as a rotating beacon of spin-polarized nuclei and a beta-telescope detection system. Prototype experiments are now underway with the initial goal of making a 1% measurements of the beta-asymmetry parameter A which would match the world's best measurements

368

Particle sizing of airborne radioactivity field measurements at Olympic Dam  

Energy Technology Data Exchange (ETDEWEB)

On July 1, 1991 the Australian Radiation Laboratory (ARL) commenced a two year project entitled - Particle sizing of airborne radioactivity, funded by a Mining and Quarrying Occupational Health and Safety Committee - grant (submission No. 9138). This study was set out to measure airborne radioactivity size distributions in an underground uranium mine, in order to provide better estimates of the health risks associated with inhalation of airborne radiation in the work place. These measurements included both active and passive measurement of radon gas, continuous and spot sample of radon daughter levels, as well as wire screen diffusion battery measurements of the radon daughter size distributions. The results of measurements at over 50 sites within the mine are reported, together with the calculated dose conversion factors derived from the older dosimetric models and from the new ICRP lung model using the computer code RADEP. The results showed that the ventilation is relatively uniform within the mine and the radon daughter concentrations are kept to less than 20% of the equilibrium concentration. The radon and radon daughter concentrations showed marked variability with both time and position within the mine. It is concluded that the present radiation protection methods and dose conversion factors used in Australia provide a good estimate of the radiation risk for the inhalation of radon progeny. 29 refs., 8 tabs., 9 figs.

Solomon, S.B.; Wilkis, M.; O`Brein, R.; Ganakas, G.

1993-12-01

369

Measuring the absolute water content of the brain using quantitative MRI.  

Science.gov (United States)

Methods for quantitative imaging of the brain are presented and compared. Highly precise and accurate mapping of the absolute water content and distribution, as presented here, requires a significant number of corrections and also involves mapping of other MR parameters. Here, either T(1) and T(2)(*) or T(2) is mapped, and several corrections involving the measurement of temperature, transmit and receive B(1) inhomogeneities and signal extrapolation to zero TE are applied. Information about the water content of the whole brain can be acquired in clinically acceptable measurement times (10 or 20 min). Since water content is highly regulated in the healthy brain, pathological changes can be easily identified and their evolution or correlation with other manifestations of the disease investigated. In addition to voxel-based total water content, information about the different environments of water can be gleaned from qMRI. The myelin water fraction can be extracted from the fit of very high-SNR multiple-echo T(2) decay curves with a superposition of a large number of exponentials. Diseases involving de- or dysmyelination can be investigated and lead to novel observations regarding the water compartmentalisation in tissue, despite the limited spatial coverage. In conclusion, quantitative MRI is emerging as an unparalleled tool for the study of the normal and diseased brain, replacing the customary time-space environment of the sequential mixed-contrast MRI with a multi-NMR-parametric space in which tissue microscopy is increasingly revealed. PMID:21279597

Shah, Nadim Joni; Ermer, Veronika; Oros-Peusquens, Ana-Maria

2011-01-01

370

From direct to absolute mass measurements a study of the accuracy of ISOLTRAP  

CERN Document Server

For a detailed study of the accuracy of the Penning trap mass spectrometer ISOLTRAP all expected sources of uncertainty were investigated with respect to their contributions to the uncertainty of the final result. In the course of these investigations, cross-reference measurements with singly charged carbon clusters $^{12}$C$^{+}_{n}$ were carried out. The carbon cluster ions were produced by use of laser-induced desorption, fragmentation, and ionization of C$_{60}$ fullerenes and injected into and stored in the Penning trap system. The comparison of the cyclotron frequencies of different carbon clusters has provided detailed insight into the residual systematic uncertainty of \\acro{ISOLTRAP} and yielded a value of $8 \\cdot 10^{-9}$. This also represents the current limit of mass accuracy of the apparatus. Since the unified atomic mass unit is defined as 1/12 of the mass of the $^{12}$C atom, it will be possible to carry out absolute mass measurements with \\acro{ISOLTRAP} in the future.\\\\[1\\baselineskip] PACS...

Kellerbauer, A G; Bollen, G; Herfurth, F; Kluge, H J; Kuckein, M; Sauvan, E; Scheidenberger, C; Schweikhard, L; 10.1140/epjd/e2002-00222-0

2003-01-01

371

Absolute total cross-section measurements for electron collisions with tetrahydrofuran  

International Nuclear Information System (INIS)

The absolute total cross section (TCS) for electron collisions with tetrahydrofuran C4H8O in the gas phase has been measured using the linear transmission technique within 1-370 eV energy range. The total cross section function for e--C4H8O collisions is characterized by the relatively high magnitude and the broad enhancement spanned between 4 and 12 eV, with some resonantlike structures. This enhancement can be explained as a result of overlapping core-excited resonances. At higher collision energies the magnitude of the measured total cross section monotonically decreases with the energy increase. At low impact energies some additional weak resonant features are visible near 1.9 and 3.5 eV. The reported TCS results are higher by 30% than recently published by Zecca et al. [J. Phys. B 38, 2079 (1995)]. They are also distinctly different from the recent R-matrix calculations. At intermediate energy range the present data agree well with the sum of calculated elastic and ionization cross sections

372

Use of proportional gas scintillator in absolute measurements of alpha-gamma emitter activities  

International Nuclear Information System (INIS)

The absolute activity of U-235 contained in a U3 O8 sample was measured utilizing a sum-coincidence circuit which selects only the alpha particles which are simultaneous with the 143 KeV and 186 KeV gamma radiations from the Th-231 (product nucleus). The alpha particles were detected by means of a new type of a gas scintillating chamber, in which the light emitted by excitation of the gas atoms, due to the passage of a charged incoming particle, has its intensity increased by the action of an applied electric field. The gamma radiations were detected by means of a NaI(Tl) 1'' x 11/2'' scintillation detector. The value obtained for the half-life of U-235 was compared with the data available from various observers which used different experimental techniques. It is shown tht the results, are in excellent agreement with the best international data available on the subject and that, therefore, the sum-coincidence technique constitutes an important method for such measurements. (Author)

373

Superheterodyne configuration for two-wavelength interferometry applied to absolute distance measurement.  

Science.gov (United States)

We present a new superheterodyne technique for long-distance measurements by two-wavelength interferometry (TWI). While conventional systems use two acousto-optic modulators to generate two different heterodyne frequencies, here the two frequencies result from synchronized sweeps of optical and radio frequencies. A distributed feedback laser source is injected in an intensity modulator that is driven at the half-wave voltage mode. A radio-frequency signal is applied to this intensity modulator to generate two optical sidebands around the optical carrier. This applied radio frequency consists of a digital ramp between 13 and 15 GHz, with 1 ms duration and with an accuracy of better than 1 ppm. Simultaneously, the laser source is frequency modulated by a current modulation that is synchronized on the radio-frequency ramp as well as on a triangle waveform. These two frequency-swept optical signals at the output of the modulator illuminate a Michelson interferometer and create two distinct distance-dependent heterodyne frequencies on the photodetector. The superheterodyne signal is then detected and bandpass filtered to retrieve the absolute distance measurement. Experiments between 1 and 15 m confirm the validity of this new concept, leading to a distance accuracy of +/- 50 microm for a 1 ms acquisition time. PMID:20119024

Le Floch, Sébastien; Salvadé, Yves; Droz, Nathalie; Mitouassiwou, Rostand; Favre, Patrick

2010-02-01

374

Superheterodyne configuration for two-wavelength interferometry applied to absolute distance measurement  

Energy Technology Data Exchange (ETDEWEB)

We present a new superheterodyne technique for long-distance measurements by two-wavelength interferometry (TWI). While conventional systems use two acousto-optic modulators to generate two different heterodyne frequencies, here the two frequencies result from synchronized sweeps of optical and radio frequencies. A distributed feedback laser source is injected in an intensity modulator that is driven at the half-wave voltage mode. A radio-frequency signal is applied to this intensity modulator to generate two optical sidebands around the optical carrier. This applied radio frequency consists of a digital ramp between 13 and 15 GHz, with 1 ms duration and with an accuracy of better than 1 ppm. Simultaneously, the laser source is frequency modulated by a current modulation that is synchronized on the radio-frequency ramp as well as on a triangle waveform. These two frequency-swept optical signals at the output of the modulator illuminate a Michelson interferometer and create two distinct distance-dependent heterodyne frequencies on the photodetector. The superheterodyne signal is then detected and bandpass filtered to retrieve the absolute distance measurement. Experiments between 1 and 15 m confirm the validity of this new concept, leading to a distance accuracy of {+-} 50 {mu}m for a 1 ms acquisition time.

Le Floch, Sebastien; Salvade, Yves; Droz, Nathalie; Mitouassiwou, Rostand; Favre, Patrick

2010-02-01

375

Superheterodyne configuration for two-wavelength interferometry applied to absolute distance measurement  

International Nuclear Information System (INIS)

We present a new superheterodyne technique for long-distance measurements by two-wavelength interferometry (TWI). While conventional systems use two acousto-optic modulators to generate two different heterodyne frequencies, here the two frequencies result from synchronized sweeps of optical and radio frequencies. A distributed feedback laser source is injected in an intensity modulator that is driven at the half-wave voltage mode. A radio-frequency signal is applied to this intensity modulator to generate two optical sidebands around the optical carrier. This applied radio frequency consists of a digital ramp between 13 and 15 GHz, with 1 ms duration and with an accuracy of better than 1 ppm. Simultaneously, the laser source is frequency modulated by a current modulation that is synchronized on the radio-frequency ramp as well as on a triangle waveform. These two frequency-swept optical signals at the output of the modulator illuminate a Michelson interferometer and create two distinct distance-dependent heterodyne frequencies on the photodetector. The superheterodyne signal is then detected and bandpass filtered to retrieve the absolute distance measurement. Experiments between 1 and 15 m confirm the validity of this new concept, leading to a distance accuracy of ± 50 ?m for a 1 ms acquisition time.

376

Neutron absolute and total cross section difference measurements in the mass-140 region  

Science.gov (United States)

We have used a 100-MeV electron linac and neutron time-of-flight facility to measure precise neutron total cross sections in the mass-140 region for incident neutron energies of 3-60 MeV. We measured the absolute neutron total cross section of 140Ce and the total cross section differences of 139La-140Ce, 141Pr-140Ce, and 142Ce-140Ce. These cross section differences oscillate with energy. Optical model calculations have been performed which fit the 140Ce total cross section well over the 3-60 MeV energy region. The 139La-140Ce and 141Pr-140Ce difference data were satisfactorily fit by small changes in the geometrical parameters of the potential. The 142Ce-140Ce data could not be fit by small changes in the geometry of the potential and we found that the changes required to achieve a satisfactory fit suggest that 142Ce is either nonspherical or more easily deformed than 140Ce. Using our final optical model parameters we calculated ?(r2)=A-140 for the real part of the potential. The 139La-140Ce and 141Pr-140Ce optical model values of ?(r2) were in agreement with corresponding ?(r2)q values calculated using muonic x-ray data. The value for 142Ce-140Ce was not.

Camarda, H. S.; Phillips, T. W.; White, R. M.

1984-06-01

377

Absolute temperature measurements using a two-color QWIP focal plane array  

Science.gov (United States)

The infrared photon flux emitted by an object depends not only on its temperature but also on a proportionality factor referred to as its emissivity. Since the latter parameter is usually not known quantitatively a priori, any temperature determination based on single-band radiometric measurements suffers from an inherent uncertainty. Recording photon fluxes in two separate spectral bands can in principle circumvent this limitation. The technique amounts to solving a system of two equations in two unknowns, namely, temperature and emissivity. The temperature derived in this manner can be considered absolute in the sense that it is independent of the emissivity, as long as that emissivity is the same in both bands. QmagiQ has previously developed a 320x256 midwave/longwave staring focal plane array which has been packaged into a dual-band laboratory camera. The camera in question constitutes a natural tool to generate simultaneous and independent emissivity maps and temperature maps of entire two-dimensional scenes, rather than at a single point on an object of interest. We describe a series of measurements we have performed on a variety of targets of different emissivities and temperatures. We examine various factors that affect the accuracy of the technique. They include the influence of the ambient radiation reflected off the target, which must be properly accounted for and subtracted from the collected signal in order to lead to the true target temperature. We also quantify the consequences of spectrally varying emissivities.

Bundas, Jason; Dennis, Richard; Patnaude, Kelly; Burrows, Douglas; Faska, Ross; Sundaram, Mani; Reisinger, Axel; Manitakos, Dan

2010-04-01

378

An Absolute Measurement of the Cosmic Microwave Background Radiation Temperature at 10.7 GHz  

CERN Document Server

A balloon-borne experiment has measured the absolute temperature of the cosmic microwave background radiation (CMBR) at 10.7 GHz to be Tcmbr = 2.730 +- .014 K. The error is the quadratic sum of several systematic errors, with statistical error of less than 0.1 mK. The instrument comprises a cooled corrugated horn antenna coupled to a total-power radiometer. A cryogenic mechanical waveguide switch alternately connects the radiometer to the horn and to an internal reference load. The small measured temperature difference (<= 20 mK) between the sky signal and the reference load in conjunction with the use of a cold front end keeps systematic instrumental corrections small. Atmospheric and window emission are minimized by flying the instrument at 24 km altitude. A large outer ground screen and smaller inner screen shield the instrument from stray radiation from the ground and the balloon. In-flight tests constrain the magnitude of ground radiation contamination, and low level interference is monitored through ...

Staggs, S T; Meyer, S; Wilkinson, D T

1996-01-01

379

Establishing radioactivity measurement capabilities for nuclear medicine in Member States  

International Nuclear Information System (INIS)

Full text: The International Atomic Energy Agency (IAEA), in response to a growing need for measurement quality assurance for radionuclides used in nuclear medicine, particularly in developing countries, is establishing a new radioactivity standardization programme in the Dosimetry and Medical Radiation Physics Section. The short-term (3-5 years) goals of this project are to: 1) Develop capabilities within the IAEA to prepare and distribute calibrated solution sources of medically relevant radionuclides, traceable to international standards, to Member States for use in calibrating instrumentation. Traceability will be established through comparisons with primary National Measurement Laboratories, as well as with the International Reference System for activity measurements of the BIPM. Ultimately, the goal will be for the Agency to be able to distribute standard sources of the most relevant radionuclides to Member States that require them as part of a secondary standards radioactivity laboratory network. The laboratories in the network will then provide calibration and auditing services to nuclear medicine clinics on a national or regional basis. Formation of the laboratory network is ongoing. 2) Assist Member States in the development of quality assurance networks for nuclear medicine clinics in their countries. This could be accomplished through Technical Cooperation projects at the national and regional levels and will take the form of personnel training and consultthe form of personnel training and consultations to develop appropriate quality assurance and audit systems, and in some cases, donation of appropriate instrumentation. Further, a Coordinated Research Project has recently been approved to develop a uniform code of practice for clinical radioactivity measurements. Formation of the research group will begin in early 2004. (author)

380

An accurate absolute-scale measurement of bremsstrahlung following absorption of incident X and ? rays  

International Nuclear Information System (INIS)

The spectrum of bremsstrahlung due to photoelectrons ejected by incident photons of energy 59.5 keV was measured. The coincidence setup with two HP germanium detectors was applied, in which the target-detector recorded the energy of ejected photoelectron after it radiated a bremsstrahlung photon, and another (second) detector detected energy of radiated bremsstrahlung photon. A detailed analysis of the measurement was made taking into account various detector-to-detector cross-talk processes. As expected, the experimental method gave a clean spectrum, which can be reliably determined on absolute scale in the low- and mid-energy range. The condition for reliable measurement are that the asymmetry ratio (the ratio of number of incident photons which reached the target detector and the second detector) is higher than approximately 1000 to reduce reverse-Compton scattering, and solid angle is smaller than about 0.15 sr to reduce the influence of double-cross-talk processes. (We name a group of processes double-cross-talk processes in which incident radiation produces secondary radiation in target detector, the secondary radiation escapes it and reaches the second detector where it induces tertiary radiation, which reaches the target detector and is absorbed therein.) Almost any line source of photons can be used even if of a complex spectrum. Therefore, simultaneous measurements at several incident energies are possible in one experiment. Application of a very weak sourceeriment. Application of a very weak source is possible because of very high signal-to-background ratio and high efficiency of the applied experimental method. The simple theoretical model of bremsstrahlung radiation due to photoelectrons in infinity-thick target gives results in a good agreement with the experimental data. The bremsstrahlung cross-section calculated using the well-known semi-empirical thick-target formula gives also a good agreement with the experimental data. (author)

381

Absolute measurement of the cross section for 23 keV neutron activation of thorium  

International Nuclear Information System (INIS)

Measurement has been made of the thorium radiative capture cross section using Sb-Be photoneutrons and an absolute activation method. The average of two determinations gave a value of 604 mb at 23 keV neutron energy with a 4% estimated error from all sources (+-1 sigma). In each experiment, a cylindrical shell target of natural thorium metal was irradiated for approximately two weeks by a centrally-positioned Sb-Be source. The accumulated 27-day half-life 233Pa, activated by neutron capture in thorium, was recovered by solvent extraction with diisobutylcarbinol after first dissolving the target in hydrochloric acid. Ninety percent recovery of protactinium was obtained, as measured by isotopic tracing with 232Pa. The 1.3-day half-life 232Pa had to be produced immediately before each use. A thin thorium foil was irradiated with 11 MeV protons using a tandem van de Graaff accelerator. The 232Pa was then recovered by chemical separation. 233Pa activity was measured by counting the 312-keV decay gamma with a Ge(Li) detector. Detector efficiency was determined by indirect calibration against a 237Np deposit assayed by alpha counting at the National Bureau of Standards. The Sb-Be source strength was measured by the manganese bath method, using a 252Cf source for calibration, traceable to the NBS II neutron standard. Flux per unit source strength was determined by Monte Carlo modelling of the source/ed by Monte Carlo modelling of the source/target irradiation geometry

382

Radioactivity  

International Nuclear Information System (INIS)

In this chapter the phenomenon of radioactivity is explained. The various decay modes, rate and time of decay, the unit system - old and new, non-natural and produced radionuclides and daughter products are discussed. (G.H.)

383

Radioactivity  

International Nuclear Information System (INIS)

Tables are presented of trends in annual emissions of radioactive gaseous effluents at sites of civil establishments in the U.K. Trends in the discharge to surface and coastal water sites in the U.K. and trends in the radioactivity of solid wastes dumped in the N.E. Atlantic and in the volume and activity level of wastes disposed at sites in the U.K. are presented. Tables of radioactivity in samples of fish and shellfish at selected sites are presented. Radioactivity from global fallout and the annual mean ratio of 90Sr to calcium, and concentrations of 137Cs in milk are given. Trends in estimated collective doses from the consumption of fish and shellfish in the U.K. and Europe are presented. (U.K.)

384

Measurements of radioactive and xenobiotic substances in the biosphere in The Netherlands 1984  

International Nuclear Information System (INIS)

In this annual report the results and conclusions are given of radioactive and xenobiotic substances in the biosphere of the Netherlands. The measurements are coordinated by the Coordination Committee for the Monitoring of Radioactive and Xenobiotic substances. (Auth.)

385

Measurements of radioactive and xenobiotic substances in the biosphere in The Netherlands 1985  

International Nuclear Information System (INIS)

In this annual report the results and conclusions are given of radioactive and xenobiotic substances in the biosphere of the Netherlands. The measurements are coordinated by the Coordination Committee for the Monitoring of Radioactive and Xenobiotic substances. (Auth.)

386

? radioactive aerosol's measurement and analysis in an area  

International Nuclear Information System (INIS)

In order to know long-life radioactive aerosol's concentration in the atmosphere in three places of the area, evaluate radioactive environment's quality and the radioactive aerosol's infection to the teachers and students, we investigate radioactive aerosol's concentration in the working place, living place and teaching place of the area. The result shows that the radioactive aerosol's concentration of the area is under the country's control criterion. (authors)

387

The observatories for the radioactivity. results of measures  

International Nuclear Information System (INIS)

This IPSN's report on the monitoring of the radioactivity in France provides many graphs and tables of measures results recorded during the year 2000. The graphs show the activity levels (Bq or Bq fraction, per mass or volume unit) of many radionuclides in selected indicators and for levels upper than the detection limits. The metrology and the selected samples are presented. These samples are different for the three types of observatories: atmospheric, coast and terrestrial observatories. A chronological account of the results from 1959 to 2000 is also provided for the Cesium 137 and the beryllium 7 in the aerosols. (A.L.B.)

388

Environmental radioactivity measurements Using a compton suppression spectrometer  

International Nuclear Information System (INIS)

The natural and artificial radioactivities of some environmental samples such as soil and vegetables have been studied through gamma-ray spectroscopy with a new constructed compton suppression spectrometer (CSS). The spectrometer consists of a 10% p-type HPGe detector as a main detector, an annular NE-102 A plastic scintillator as a guard detector, and a fast-slow coincidence system employing standard electronic modules for anti-compton operation. This study shows that CSS is a powerful tool for measuring the low level activities of environmental samples

389

Aerial measurements of radioactivity and meteorological parameters in real time  

International Nuclear Information System (INIS)

The aircrafts operating in the case of nuclear accidents have to be equipped with all necessary instruments for radioactivity, aerosol and gas sampling, chemical characterization and additional avionic for exact flight path recordings. In close cooperation with NIR, AERODATA, FAG and FhG-IFU will provide the research aircraft Beechcraft King Air 200 and/or Hawker Siddeley 125. Impactors and denuders are to be installed on the aircraft for particle and gaseous measurements. The aircraft should be made available in stand-by operation

390

Direct reaction measurements with a 132Sn radioactive ion beam  

OpenAIRE

The (d,p) neutron transfer and (d,d) elastic scattering reactions were measured in inverse kinematics using a radioactive ion beam of 132Sn at 630 MeV. The elastic scattering data were taken in a region where Rutherford scattering dominated the reaction, and nuclear effects account for less than 8% of the cross section. The magnitude of the nuclear effects was found to be independent of the optical potential used, allowing the transfer data to be normalized in a reliable man...

Jones, K. L.; Adekola, A. S.; Bardayan, D. W.; Blackmon, J. C.; Chae, K. Y.; Chipps, K. A.; Cizewski, J. A.; Erikson, L.; Harlin, C.; Hatarik, R.; Kapler, R.; Kozub, R. L.; Liang, J. F.; Livesay, R.; Ma, Z.

2011-01-01

391

Measurement and preliminary behavioral model of radioactive 'geoaerosols'  

International Nuclear Information System (INIS)

Greater than anticipated activity from the ?- and ?-emitting radionuclides 230Th + 226Ra, 210Po, and 210Pb was observed in solution during modification of an air sampler1 to improve the sensitivity of measuring airborne radioactivity. Typical ?-activities ranged from several mBq to 15 Bq. We use the term 'geoaerosols'2 to describe the particles' unique transport and propose a distinct quantum phenomenon mechanism to explain the radiation accumulation. If confirmed by subsequent experiments, the technique has potential for many practical applications such as locating faults or fractures, earthquake prediction, mineral and energy resource exploration, verification of underground nuclear testing, and refining risk estimates from environmental exposure to particles. (author)

392

Absolute measurement of dielectronic recombination for C3+ in a known external field  

International Nuclear Information System (INIS)

An absolute measurement of the rate coefficient for dielectronic recombination (DR) of C3+, via the 2s-2p core excitation, in an external electric field of 11.4±0.9(1?) Vcm-1 is presented. An inclined-beam arrangement is used and the stabilizing photons at ?155 nm are detected in delayed coincidence with the recombined ions. The full width at half maximum of the electron energy spread in the ion rest frame is 1.74±0.22(1?) eV. The measured DR rate, at a mean electron energy of 8.26±0.07(1?) eV, is (2.76±0.75)x10-10 cm3s-1. The uncertainty quoted for the DR rate is the total uncertainty, systematic and statistical, at the 1? level. In comparing the present results to theory, a semiempirical formula is used to determine which recombined ion states are ionized by the 4.65 kVcm-1 fields in the final-charge-state analyzer and not detected. For the present results, any DR of the incident electrons into n levels greater than 44 is assumed to be field ionized in the final-charge-state analyzer. A more precise treatment of field ionization, which includes the lifetime of the C2+ ions before they are ionized and the time evolution and rotation of the fields experienced by the recombined ions, is needed before a definitive comparison between experiment and theory can be made. Our DR measurement, within the limits of that approach, agrees reasonably well with an intermediate coupling calculatiointermediate coupling calculation that uses an isolated resonance, single-configuration approximation, but does not agree with pure LS-coupling calculations. copyright 1996 The American Physical Society

393

Absolute measurements of fast fission cross sections for 235U and 239Pu  

International Nuclear Information System (INIS)

The fission cross sections of 235U and 239Pu for Na--Be, La--Be, Na--D and Ga--D photoneutrons were measured absolutely. In addition, the spectrum-averaged fission cross sections were measured for 252Cf fission neutrons. Values of 1.471 +- 0.024, 1.274 +- 0.020, 1.162 +- 0.022 and 1.210 +- 0.025 barns were obtained for the 235U fission cross section at nominal neutron energies of 140, 265, 770, and 964 keV (where the measurement at 964 keV was principally carried out by D.M. Gilliam, and his results are included here for completeness). Corresponding values of 1.469 +- 0.041, 1.515 +- 0.035, 1.670 +- 0.037 and 1.643 +- 0.033 barns were obtained for 239Pu. Subsequent fission ratios of 0.999 +- 0.031, 1.189 +- 0.30, 1.437 +- 0.040 and 1.358 +- 0.032 are free of any source yield dependencies. The Cf spectrum-averaged values are 1.215 +- 0.017, 1.790 +- 0.034 and 1.473 +- 0.033 for 235U(n,f), 239Pu(n,f) and 239Pu(n,f)/235U(n,f) ratio respectively. The indicated uncertainties include approximately 1.0 percent random error. All uncorrelated errors are summed in quadrature and are quoted as one standard deviation

394

Study of a 4??-? coincidence system for absolute radionuclide activity measurement using plastic scintillators  

International Nuclear Information System (INIS)

The present work was intended to study a coincidence system 4?(PS)?-? for absolute activity measurement using plastic scintillators in 4? geometry. Along with experiments on the coincidence system, simulations were also performed applying the Monte Carlo Method, by means of codes PENELOPE and ESQUEMA. These simulations were performed in order to calculate the extrapolation curve of the coincidence system 4?(PS)?-? and compare it to experimental data. A new geometry was proposed to the coincidence system adding up a second photomultiplier tube to the previous system for improving light collection from the plastic scintillator, as this system presented limitations in the minimum detected energy due to the presence of electronic noise and low gain. The results show that an improvement in the signal-to-noise ratio was obtained, as well as in the minimum detected energy. Moreover, there was an increase in the detection efficiency. With these modifications, it is now possible to calibrate radionuclides which emit low energy electrons or X-rays, increasing the number of radionuclides that can be standardized with this type of system.(author)

395

ARCADE 2 Measurement of the Absolute Sky Brightness at 3-90 GHz  

Science.gov (United States)

The ARCADE 2 instrument has measured the absolute temperature of the sky at frequencies 3, 8, 10, 30, and 90 GHz, using an open-aperture cryogenic instrument observing at balloon altitudes with no emissive windows between the beam-forming optics and the sky. An external blackbody calibrator provides an in situ reference. Systematic errors were greatly reduced by using differential radiometers and cooling all critical components to physical temperatures approximating the cosmic microwave background (CMB) temperature. A linear model is used to compare the output of each radiometer to a set of thermometers on the instrument. Small corrections are made for the residual emission from the flight train, balloon, atmosphere, and foreground Galactic emission. The ARCADE 2 data alone show an excess radio rise of 54 ± 6 mK at 3.3 GHz in addition to a CMB temperature of 2.731 ± 0.004 K. Combining the ARCADE 2 data with data from the literature shows an excess power-law spectrum of T = 24.1 ± 2.1 (K) (?/?0)-2.599 ± 0.036 from 22 MHz to 10 GHz (?0 = 310 MHz) in addition to a CMB temperature of 2.725 ± 0.001 K.

Fixsen, D. J.; Kogut, A.; Levin, S.; Limon, M.; Lubin, P.; Mirel, P.; Seiffert, M.; Singal, J.; Wollack, E.; Villela, T.; Wuensche, C. A.

2011-06-01

396

Absolute measurements of 235U and 239Pu fission cross sections with photoneutron sources  

International Nuclear Information System (INIS)

The fission cross sections of 235U and 239Pu for Na-Be, La-Be, Na-D, and Ga-D photoneutrons have been measured absolutely (i.e., without significant dependence on other cross section data). The neutron flux at the targets was calculated from the experimental geometry and by using a manganese bath to compare the photoneutron source yield with the standard source NBS-II. Fission counts were accumulated with the source positioned symmetrically between two identical foils and detectors in an experiment package suspended in a low-albedo laboratory. Fission fragments passing through limited solid angle apertures were recorded on polyester track-etch films. The masses of the foil deposits were determined by microbalance weighings and confirmed by thermal fission and alpha counting. After making a correction for the calculated energy distribution of the source neutrons, values of 1.471, 1.271, 1.161, and 1.210 barns were obtained for the 235U fission cross section at neutrons energies of 140, 265, 770, and 964 keV, respectively. Corresponding values of 1.465, 1.490, 1.678, and 1.644 barns were derived for 239Pu. Present uncertainties are about 2.0 percent for the 235U values and 2.5 percent for the 239Pu results

397

ARCADE 2 MEASUREMENT OF THE ABSOLUTE SKY BRIGHTNESS AT 3-90 GHz  

International Nuclear Information System (INIS)

The ARCADE 2 instrument has measured the absolute temperature of the sky at frequencies 3, 8, 10, 30, and 90 GHz, using an open-aperture cryogenic instrument observing at balloon altitudes with no emissive windows between the beam-forming optics and the sky. An external blackbody calibrator provides an in situ reference. Systematic errors were greatly reduced by using differential radiometers and cooling all critical components to physical temperatures approximating the cosmic microwave background (CMB) temperature. A linear model is used to compare the output of each radiometer to a set of thermometers on the instrument. Small corrections are made for the residual emission from the flight train, balloon, atmosphere, and foreground Galactic emission. The ARCADE 2 data alone show an excess radio rise of 54 ± 6 mK at 3.3 GHz in addition to a CMB temperature of 2.731 ± 0.004 K. Combining the ARCADE 2 data with data from the literature shows an excess power-law spectrum of T = 24.1 ± 2.1 (K) (?/?0)-2.599±0.036 from 22 MHz to 10 GHz (?0 = 310 MHz) in addition to a CMB temperature of 2.725 ± 0.001 K.

398

Absolute neutron capture cross sections of uranium-238 by spherical shell transmission measurements  

International Nuclear Information System (INIS)

The required accuracy of capture cross sections of the fertile isotope 238U in the keV-region is 1 - 2%. In experiments is achieved 3 - 5% now, but the data have discrepancies up to 20%. An analysis of literature data at 24 and 30 keV has given average values with an uncertainty of +-10%. In a spherical shell transmission experiment in indirect geometry on the 1000 m-TOF-path of the pulsed fast reactor IBR-30 of the JINR Dubna the sphere transmission function has been measured in a wide energy range using 3He-proportional counter batteries and five shell targets. Absolute average ABBN-group capture cross sections of 238U in the energy range 215 eV to 100 keV and capture cross sections of 24 and 30 keV have been determined using Monte Carlo calculations and two different methods to consider the resonance self shielding effect. The accuracy of the data is about 5%. The results are compared with literature data and support the tendency of the less increasing capture cross section of 238U from 40 keV down to 1 keV. In this energy range they are about 10 - 20% lower than the ABBN-70 data. (author)

399

Measuring radon progeny and thoron progeny in air by absolute beta counting subsequent to grab sampling  

Energy Technology Data Exchange (ETDEWEB)

A new grab sampling method for the simultaneous determination of radon progeny and thoron progeny in air has been developed and demonstrated by the first author of this paper a few years ago. The characteristics and capabilities of this method are discussed in the present paper in detail. The method is based on gross beta counting of filtered aerosol samples counted over successive time intervals using an end-window Geiger-Muller counter. The measured counting rate versus time curve is analyzed by fitting to it some linear combination of the theoretical decay curves of the decay products with the knowledge of the counting efficiencies and some other quantities. Defined solid angle absolute beta counting was used to evaluate the counting efficiencies for the decay products one by one. So, the method is an absolute one that does not demand further calibration. The decay products of radon and thoron can be determined separately and simultaneously. The systematic error of the results, deriving from the inaccurate evaluation of the counting efficiencies, is probably lower and can be estimated more surely than that of the methods based on alpha counting. The method is highly sensitive: accurate results can be obtained for {sup 214}Pb, {sup 214}Bi, {sup 212}Pb, EEDC{sub 222} and EEDC{sub 220} even outdoors. However, the results for {sup 218}Po and {sup 212}Bi are much more inaccurate and {sup 208}Tl cannot be determined at all. The reliability of the determinations can be raised significantly using conditional computations based on the information obtainable from some theoretical considerations and models. The method can be used in a broad activity concentration range, equally in caves, mines, houses or outdoors. The above characteristics and capabilities of the method are demonstrated in this paper through the detailed presentation and analysis of the results obtained for three samplings performed indoors in a house, in a cave, and outdoors, respectively. The known advantages and drawbacks of the method are also surveyed in detail.

Papp, Z. [Department of Environmental Physics, University of Debrecen, PO Box 51, Debrecen 4001 (Hungary)]. E-mail: zpapp@atomki.hu; Dezso, Z. [Department of Environmental Physics, University of Debrecen, PO Box 51, Debrecen 4001 (Hungary)

2006-05-15

400

Using relative and absolute measures for monitoring health inequalities: experiences from cross-national analyses on maternal and child health  

OpenAIRE

Abstract Background As reducing socio-economic inequalities in health is an important public health objective, monitoring of these inequalities is an important public health task. The specific inequality measure used can influence the conclusions drawn, and there is no consensus on which measure is most meaningful. The key issue raising most debate is whether to use relative or absolute inequality measures. Our paper aims to inform this debate and develop recommendations for ...

Huisman Martijn; Kunst Anton E; Aj, Houweling Tanja; Mackenbach Johan P

2007-01-01

401

Absolute measurement of the desintegration rate of 137 Cs by 4? (BS) e--X coincidence method  

International Nuclear Information System (INIS)

The method developed by the Nuclear Metrology Laboratory for the absolute measurement of the desintegration rate of 137Cs by 4?(BS)e--X is described. The conversion electron are measured by a pair of surface barrier detectors with 200mm2 of active area and 1000?m of depletion depth. The X-rays are measured by two 50.8mm diameter and 1.0mm thick NaI (Tl) scintillation counters. (author)

402

Environmental Radioactivity Measurements in Harran Plain of Sanliurfa, Turkey  

International Nuclear Information System (INIS)

This study aims to assess the environmental radioactivity levels of Harran Plain located within the boundaries of the south-eastern province of Sanliurfa, Turkey. In addition to being at the center of Turkey's major irrigation and development project (South Eastern Anatolian Project, GAP), this 1500 km2 region is famous for its historic attractions. The outdoor gamma dose rates were measured at selected points of the study area using a plastic scintillator. The activity concentrations in the soil samples collected from the study area were determined by gamma spectrometry for the natural radionuclides 238U, 232Th and 40K and the fission product 137Cs. The gross alpha and beta activities in the water samples collected from the region was measured using a low-level gamma spectrometry device. A comparison of the measurement results obtained in this study with those of national and world averages are presented in graphical and tabular forms

403

A method for measuring the viscosity of radioactive waste glasses  

International Nuclear Information System (INIS)

A technique is described for measuring the viscosity of glass containing radioactive components which allows for the restrictions of working in a limited space with remote-handling facilities and the need to use a minimum quantity of the glass product. The method is based on the determination of the viscous drag on a cylindrical steel rod falling freely through the glass contained in a cylindrical steel vessel. The measurement made is the rate of fall of the rod as a function of the penetration depth. Results are given for standard glasses and a simulated waste glass; they show that, with appropriate counting and recording techniques, measurements can be made over the range 107-103 P. (author)

404

Absolute light yield measurements on SrF$_{2}$ and BaF$_{2}$ doped with rare earth ions  

CERN Document Server

Results of absolute light output measurements on strontium and barium fluoride doped with PrF$_3$ and CeF$_3$ are presented and compared with scintillators having well-known light output (NaI-Tl, CsI-Tl, BGO). For pure SrF$_2$ crystal we obtain a value of about 28600 photons/MeV.

Shendrik, Roman

2013-01-01

405

Recent developments at Saclay for measuring absolute cross sections of reactions between heavy ions by in-beam gamma techniques  

International Nuclear Information System (INIS)

The potentiality of the in-beam gamma techniques to measure absolute cross sections in the fusion-evaporation domain is discussed. These techniques have been used (with Ge(Li) detectors) for more than one decade, but in view of the considerable progress which has been achieved in the last years, it seems worth while to reconsider to day their merits and limitations

406

Use of parallel plate avalanche detectors for absolute photofission cross section measurement on 238U and 232Th  

International Nuclear Information System (INIS)

This paper is a digest of a series of studies on parallel plate avalanche detectors, built with the purpose of measuring absolute photofission cross section on 238U and 232Th. Besides a few theoretical recallings, we describe the experimental configuration, and point out the various problems met during its elaboration, and their respective solutions

407

The orbit of Phi Cygni measured with long-baseline optical interferometry - Component masses and absolute magnitudes  

Science.gov (United States)

The orbit of the double-lined spectroscopic binary Phi Cygni, the distance to the system, and the masses and absolute magnitudes of its components are presented via measurements with the Mar III Optical Interferometer. On the basis of a reexamination of the spectroscopic data of Rach & Herbig (1961), the values and uncertainties are adopted for the period and the projected semimajor axes from the present fit to the spectroscopic data and the values of the remaining elements from the present fit to the Mark III data. The elements of the true orbit are derived, and the masses and absolute magnitudes of the components, and the distance to the system are calculated.

Armstrong, J. T.; Hummel, C. A.; Quirrenbach, A.; Buscher, D. F.; Mozurkewich, D.; Vivekanand, M.; Simon, R. S.; Denison, C. S.; Johnston, K. J.; Pan, X.-P.

1992-01-01

408

Measurement of absolute E2 transition strengths in 176W: Signatures for a rapid shape change  

International Nuclear Information System (INIS)

The X(5) symmetry describes nuclei at the critical point of the shape phase transition from axially deformed rotor nuclei to spherical vibrators. 150Nd, 152Sm, and 154Gd were the first nuclei where the predicted characteristics of the X(5) symmetry were observed. Later it was shown that also 176,178,180Os can be successfully described with the X(5) symmetry.In the close vicinity of shape phase transitions one expects strongly changing nuclear shapes. In the X(5) region around A = 150 this was observed for nuclei with different neutron numbers, whereas in the X(5) region around A = 180 this is to be expected for different proton numbers. The aim of the work presented here is the confirmation of a rapid shape change for nuclei close to 178Os. Besides the knowledge on the level scheme of the nuclei of interest, especially absolute E2 transition strengths are crucial for the interpretation of nuclear structure. Prolate deformation is expected for 176W. Thus we performed a recoil distance Doppler shift (RDDS) measurement on 176W to measure E2 transition strengths from level lifetimes. The experiment was performed at the Cologne FN TANDEM accelerator with the Cologne coincidence plunger with the reaction 169Dy(16O,4n)176W and a beam energy of 80 MeV. We will present our experimental results and relate them to data on the neighboring nuclei 178Os and ghboring nuclei 178Os and 182Pt. The results will be discussed in the framework of nuclear shape transitions in this mass region and compared to calculations with both the Interacting Boson Model (IBM) and the GCM.

409

Can compliant fault zones be used to measure absolute stresses in the upper crust?  

Science.gov (United States)

Geodetic and seismic observations reveal long-lived zones with reduced elastic moduli along active crustal faults. These fault zones localize strain from nearby earthquakes, consistent with the response of a compliant, elastic layer. Fault zone trapped wave studies documented a small reduction in P and S wave velocities along the Johnson Valley Fault caused by the 1999 Hector Mine earthquake. This reduction presumably perturbed a permanent compliant structure associated with the fault. The inferred changes in the fault zone compliance may produce a measurable deformation in response to background (tectonic) stresses. This deformation should have the same sense as the background stress, rather than the coseismic stress change. Here we investigate how the observed deformation of compliant zones in the Mojave Desert can be used to constrain the fault zone structure and stresses in the upper crust. We find that gravitational contraction of the coseismically softened zones should cause centimeters of coseismic subsidence of both the compliant zones and the surrounding region, unless the compliant fault zones are shallow and narrow, or essentially incompressible. We prefer the latter interpretation because profiles of line of sight displacements across compliant zones cannot be fit by a narrow, shallow compliant zone. Strain of the Camp Rock and Pinto Mountain fault zones during the Hector Mine and Landers earthquakes suggests that background deviatoric stresses are broadly consistent with Mohr-Coulomb theory in the Mojave upper crust (with ? ? 0.7). Large uncertainties in Mojave compliant zone properties and geometry preclude more precise estimates of crustal stresses in this region. With improved imaging of the geometry and elastic properties of compliant zones, and with precise measurements of their strain in response to future earthquakes, the modeling approach we describe here may eventually provide robust estimates of absolute crustal stress.

Hearn, E. H.; Fialko, Y.

2009-04-01

410

Measurement of radioactive soil contamination from the air  

International Nuclear Information System (INIS)

In-situ gamma spectrometry can be used to determine the qualitative and quantitative deposition of radioactive materials on the ground surface. By applying the in-situ spectrometry method using either a helicopter or an airplane, large areas can be scanned in a short period of time. In this report the results of in-situ gamma spectroscopic measurements taken from a helicopter are described. Measurements were carried out using a single point source, a field of 36 point sources, and using the present ground contamination due to fall-out from the Chernobyl accident and atom bombs. The results of these measurements were used to determine calibration factors, which were in agreement with a calibration obtained using more simple (and less expensive) laboratory measurements in combination with flux calculations. Detection limits for the measurement of surface contamination were determined. At a height of 50 meters above the surface and using a measurement time of 2 minutes, the minimally detectable surface contamination was 1.1 kBqm-2 for a Cs-137 contamination and 2.1 kBqm-2 for I-131 contamination. Fall-out determinations based on measurements taken at a height of 50 meters were in agreement with determinations taken at a height of 1 meter, and with the results obtained measuring soil samples. The in-situ gamma spectroscopy, using helicopter or airplane, is a fast and powerful method for mapping surface contamination. (author). 13 refs.; 18 figs.; 13 ination. (author). 13 refs.; 18 figs.; 13 tabs

411

Radioactivity  

International Nuclear Information System (INIS)

Over 75% of the annual radiation dose received by the average person in the UK comes from natural radioactivity and about 20% is due to medical irradiation. Other radioactive sources which amount to about 0.1% of the total dose are discussed. These include 1) world-wide fallout from weapon testing with data on the annual mean ratios of strontium-90 to calcium and concentrations of caesium-137 in milk since 1958; 2) atmospheric discharges of low level radioactive waste with data on the annual mean concentrations of strontium-90 and caesium-137 in milk from farms near Sellafield, Harwell, Winfrith and Dounreay since 1972; and 3) liquid discharges of low level radioactive waste with data on the principal exposure pathways and trends in estimates of public radiation exposure since 1975 for various discharge sites belonging to BNFL, UKAEA, CEGB AND SSEB. Reference is also made to additional tables of data on radioactive emissions, concentrations and exposure in the UK which are available from the Dept. of the Environment. (U.K.)

412

Radioactive nitrogen measuring device and method in main stream system  

International Nuclear Information System (INIS)

The present invention concerns a device suitable to the analysis for the form of radioactive nitrogen in a main steam system of a BWR type reactor. Inert gases of from normal to several atmospheric pressure are previously filled in a condensator of the device. Steams are taken into the condensator by opening a branched valve of a sampling tube disposed in a main steam tube. When the inner pressure is increased to a predetermined value, the branched valve is closed. Subsequently, a chiller and a pump are actuated to condensate the steams. Since the steams are condensated in the inert gases, NO is not oxidized but stays in the gas phase, and NO2 and NH3 easily soluble to water at low temperature are transferred into condensated water and deposited in the bottom. Accordingly, the time delay in measurement can be estimated accurately and the concentration of radioactive nitrogen in the main steams can be measured accurately on every chemical forms. (I.N.)

413

Quality assurance for radioactive measurement in nuclear medicine  

International Nuclear Information System (INIS)

The field of nuclear medicine continues to grow around the world, owing in part to a number of successful programmes carried out by the IAEA to enhance the use of nuclear medicine techniques in Member States. The implementation of quality assurance (QA) programmes to ensure the safe application of radiopharmaceuticals has, however, been variable in many Member States. One possible reason is the lack of a unified set of principles regarding the establishment of such programmes. This publication addresses the issue of QA programmes for radioactivity measurement in nuclear medicine. A group of experts consulted by the IAEA recommended in 2002 that unified principles concerning QA and quality control (QC) procedures for the measurement of radioactivity in nuclear medicine be developed because of its importance in controlling the safety and effectiveness of the use of radiopharmaceuticals. This publication is the result of advice provided to the IAEA by experts in the fields of radionuclide metrology, medical physics and radiopharmacy. This report can be considered to be a more detailed and updated version of IAEA-TECDOC-602, Quality Control of Nuclear Medicine Instruments, published in 1991. Advances in the field of nuclear instrumentation since that report was published, particularly in imaging, and the increased emphasis on QA and QC prompted the need for an update. Moreover, it was realized that the activity measurement and imaging aspects had each become so specializeging aspects had each become so specialized as to be better treated in separate publications. The present report focuses on the factors affecting radioactivity measurement and the implementation of QA and QC programmes to ensure accurate and consistent results. The IAEA has developed a safety standard on The Management System for Facilities and Activities (IAEA Safety Standards Series No. GS-R-3), which replaces the IAEA publications on QA issued as Safety Series No. 50-C/SG-Q (1996). In GS-R-3, the management system is described as a set of interrelated or interacting elements for establishing policies and objectives and enabling the objectives to be achieved in a safe and efficient way. The management system is designed to fulfil requirements that integrate elements related to safety, health, the environment, security, quality and economics. Safety is the fundamental principle upon which the management system is based. It is also recognized in GS-R-3 that QC and QA are important components of the management system. While QC is a means of applying controls to ensure that the product or service consistently meets specifications, QA is an interdisciplinary management tool that provides a means for ensuring that all work is adequately planned, correctly performed and assessed. A QA programme is designed primarily to ensure the quality of a product for a customer and may be appropriate to control the activities in radioactivity measurement in nuclear medicine. However, it would be more effective if these QA controls were integrated into a single management system. There are numerous processes that review and assess financial and technical performance, the achievement of goals and the effectiveness of an organization's processes. It is necessary to integrate the results of all assessment activities to focus decision making on the needs of the business strategy. It is important to understand how assessments enable managers to achieve higher standards of performance. The principles in this publication are based on those described in IAEA Safety Standards Series No. GS-R-3 and in the General Requirements for the Competence of Testing and Calibration Laboratories (ISO/IEC 17025:1999), which set requirements that testing and calibration laboratories must meet to demonstrate that they have a management system in place and are technically competent. The present report provides information specific to implementing these standards at both the end user (clinic) and the secondary standards radioactivity laboratory levels. If adopted to their greatest extent, the principles

414

Measurement of radioactivity of linac cooling water at Nihon University  

International Nuclear Information System (INIS)

Radioactivity of the cooling water circulating the 125-MeV linac in operation has been measured at LEBRA in Nihon University in terms of positron annihilation ?-rays resulted from ?+ decays of 15O nuclei. The dose equivalent at 10 cm from the surface of the reservoir tank in the precise water temperature controller has been deduced to be higher than the limit allowed by the radiation hazard protection law. Currently the controller is placed in the accelerator room, which is not good taking account of radiation damage and daily maintenance. However, the result suggests that a necessary measure must be taken to lower the dose when the controller is moved to the modulator room. (author)

415

The NIST radioactivity measurement assurance program for the radiopharmaceutical industry.  

Science.gov (United States)

The National Institute of Standards and Technology (NIST) maintains a program for the establishment and dissemination of activity measurement standards in nuclear medicine. These standards are disseminated through Standard Reference Materials (SRMs), Calibration Services, radionuclide calibrator settings, and the NIST Radioactivity Measurement Assurance Program (NRMAP, formerly the NEI/NIST MAP). The MAP for the radiopharmaceutical industry is described here. Consolidated results show that, for over 3600 comparisons, 96% of the participants' results differed from that of NIST by less than 10%, with 98% being less than 20%. Individual radionuclide results are presented from 214 to 439 comparisons, per radionuclide, for (67)Ga, (90)Y, (99m)Tc, (99)Mo, (111)In, (125)I, (131)I, and (201)Tl. The percentage of participants results within 10% of NIST ranges from 88% to 98%. PMID:22578995

Cessna, Jeffrey T; Golas, Daniel B

2012-09-01

416

Design and construction of a cryogenic facility providing absolute measurements of radon 222 activity for developing a primary standard  

International Nuclear Information System (INIS)

Radon 222 metrology is required to obtain higher accuracy in assessing human health risks from exposure to natural radiation. This paper describes the development of a cryogenic facility that allows absolute measurements of radon 222 in order to obtain a primary standard. The method selected is the condensation of a radon 222 sample on a geometrically defined cold surface with a constant, well known and adjustable temperature and facing an alpha particles detector. Counting of the alpha particles reaching the detector and the precisely known detection geometry provide an absolute measurement of the source activity. After describing the cryogenic facility, the measurement accuracy and precision are discussed and a comparison made with other measurement systems. The relative uncertainty is below 1 pc (1 ?). The facility can also be used to improve our knowledge of the nuclear properties of radon 222 and to produce secondary standards. (author)

417

Absolute spectral irradiance measurements of lightning from 375 to 880 nm  

Science.gov (United States)

The time-integrated emissions from cloud-to-ground lightning have been recorded in the 375-880 nm region, using a spectrometer-detector and multichannel analyzer system capable of absolute spectral irradiance measurements. A schematic drawing of the detector-analyzer system is presented, and the experimental setup is described. A total of ten flashes containing 46 individual strikes were recorded and compared to recordings of 500 flashes from 1981. The average spectral irradiance from 375 to 695 nm for flashes at about 15 km was 3.5 x 10 to the -5th J/sq m per stroke with a standard deviation of 2.0 x 10 to the -5th and a range from 0.7 x 10 to the 0.7-6.8 x 10 to the -5th J/sq m per stroke. The average stroke spectra irradiance from 650 to 880 nm for the same strokes was 1.2 x 10 to the -5th, with a standard deviation of 0.7 x 10 to the -5th and a range from 0.5 to 3.2 x 10 to the -5th J/sq m per stroke. A summary table of spectral irradiance values in 50 nm increment is presented. Analysis of the spectral emission data show that unresolved neutral hydrogen lines (NI) at 744.2 nm were more intense than H-alpha emission at 656.3 nm. The strong emission of a flash with a continuing current was identified as cyanogen (CN) emission.

Orville, R. E.; Henderson, R. W.

1984-01-01

418

Absolute measurements of the fast neutron capture cross-section of In115  

International Nuclear Information System (INIS)

The In115(n,?)In/sup 116ml/ cross section has been absolutely determined at neutron energies of 23, 265, 770, and 964 keV. These energies are the median neutron energies of the four photoneutron sources, Sb-Be, Na-D2C, La-Be and Na-Be, utilized in this work. Independent determinations of the reaction rate, detector efficiency, neutron source strength, scalar flux and target masses were performed. Reaction rates were determined by beta counting of the In/sup 116ml/ decay activity using a 4? gas flow proportional counter. The detector efficiency was measured using 4??-? coincidence counting techniques. A correction factor for non-ideal detector behavior and the complex decay scheme effects was performed using the foil absorber method of efficiency extrapolation. Photoneutron source emission rates were determined by intercomparison with a Cf252 spontaneous fission neutron source in The University of Michigan Manganese Bath. The normalized scalar flux was calculated from the neutron emission angular distribution results of the Monte Carlo computer program used to model neutron and gamma transport in the source. Correction factors were applied for competing reaction activities, neutron scattering from experiment components, room-return induced activities, spectral effects in the manganese bath and the neutron energy spectra of the photoneutron sources. The neutron energy spectra were also determined with the Monte Carlo program. The ex with the Monte Carlo program. The experimental cross section results were normalized to the source median energy using the energy spectra and cross section shape data

419

The measurement of the radioactive aerosol diameter by position sensitive semiconductor detectors, 2  

International Nuclear Information System (INIS)

Determination of the diameter of radioactive aerosol is performed by using checkerboad type position sensitive semiconductor detectors (PSD). The filter paper with the radioactive aerosols is contacted to the PSD in order to calculate the diameter of the aerosol from the measured radioactivity. (author)

420

High-accuracy absolute distance measurement by two-wavelength double heterodyne interferometry with variable synthetic wavelengths  

OpenAIRE

We present an absolute distance measurement interferometer based on a two wavelength interferometer and a variable synthetic wavelength technique. The wavelength scanning range was 12 GHz, realized with a phase accuracy of 1.0 m{\\lambda} by heterodyne detection at each measurement wavelength. This small wavelength scanning range enabled the use of distributed feedback laser diodes as an interferometer light source and a fast 20 ms wavelength scanning time by injection curren...

Kuramoto, Yoshiyuki; Okuda, Hiroshi

2014-01-01

421

High-accuracy interferometer with a prism pair for measurement of the absolute refractive index of glass  

International Nuclear Information System (INIS)

We propose a variable-path interferometric technique for the measurement of the absolute refractive index of optical glasses. We use two interferometers to decide the ratio between changes in the optical path in a prism-shaped sample glass and in air resulting from displacement of the sample. The method allows precise measurements to be made without prior knowledge of the properties of the sample. The combined standard uncertainty of the proposed method is 1.6x10-6

422

3D absolute shape measurement of live rabbit hearts with a superfast two-frequency phase-shifting technique  

OpenAIRE

This paper presents a two-frequency binary phase-shifting technique to measure three-dimensional (3D) absolute shape of beating rabbit hearts. Due to the low contrast of the cardiac surface, the projector and the camera must remain focused, which poses challenges for any existing binary method where the measurement accuracy is low. To conquer this challenge, this paper proposes to utilize the optimal pulse width modulation (OPWM) technique to generate high-frequency fringe patterns, and the e...

Wang, Yajun; Laughner, Jacob I.; Efimov, Igor R.; Zhang, Song

2013-01-01

423

Absolute measurement of dielectronic recombination for C{sup 3+} in a known external field  

Energy Technology Data Exchange (ETDEWEB)

An absolute measurement of the rate coefficient for dielectronic recombination (DR) of C{sup 3+}, via the 2{ital s}-2{ital p} core excitation, in an external electric field of 11.4{plus_minus}0.9(1{sigma}) Vcm{sup {minus}1} is presented. An inclined-beam arrangement is used and the stabilizing photons at {approximately}155 nm are detected in delayed coincidence with the recombined ions. The full width at half maximum of the electron energy spread in the ion rest frame is 1.74{plus_minus}0.22(1{sigma}) eV. The measured DR rate, at a mean electron energy of 8.26{plus_minus}0.07(1{sigma}) eV, is (2.76{plus_minus}0.75){times}10{sup {minus}10} cm{sup 3}s{sup {minus}1}. The uncertainty quoted for the DR rate is the total uncertainty, systematic and statistical, at the 1{sigma} level. In comparing the present results to theory, a semiempirical formula is used to determine which recombined ion states are ionized by the 4.65 kVcm{sup {minus}1} fields in the final-charge-state analyzer and not detected. For the present results, any DR of the incident electrons into {ital n} levels greater than 44 is assumed to be field ionized in the final-charge-state analyzer. A more precise treatment of field ionization, which includes the lifetime of the C{sup 2+} ions before they are ionized and the time evolution and rotation of the fields experienced by the recombined ions, is needed before a definitive comparison between experiment and theory can be made. Our DR measurement, within the limits of that approach, agrees reasonably well with an intermediate coupling calculation that uses an isolated resonance, single-configuration approximation, but does not agree with pure {ital LS}-coupling calculations. {copyright} {ital 1996 The American Physical Society.}

Savin, D.W.; Gardner, L.D.; Reisenfeld, D.B.; Young, A.R.; Kohl, J.L. [Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138 (United States)

1996-01-01

424

Method for activity measurement in large packages of radioactive waste  

International Nuclear Information System (INIS)

When evaluating the amount of radioactivity in a package of radioactive waste from gamma measurements (dose rates, overall gamma counting or gamma spectrometry), it is usually assumed that activity and mass distributions are homogeneous, in order to calculate a transfer function. Due to the fact that neither the mass distribution, nor the activity distribution is generally homogeneous, this assumption results in an error, which is to be evaluated. This error may have a systematic part, leading to a systematic over or under-estimation of the overall activity of a family of waste packages, and a stochastic part. An easy way to evaluate a maximal value of the possible error consist in assuming a hot spot inside the waste package gathering the whole activity of the waste matters and located at extreme positions. However this assumption leads to huge and widely over-estimated values of the error, due to the fact that the single hot spot distribution is very unlikely, and secondly it does not enable the estimation of the systematic part of the error. The proposed method, OPROF-STAT, enables a much finer evaluation of the uncertainty, with an estimation of the systematic part. OPROF-STAT is based on a computed generation of virtual packages, representative of the family of real packages whose activity is to be evaluated. (N.C.)

425

Absolute qPCR for Measuring Telomere Length in Bone Marrow Samples of Plasma Cell Disorders.  

Science.gov (United States)

Telomere length (TL) is currently used as an emerging biomarker in understanding the development/progression of hematological malignancies. The absolute quantitative PCR (qPCR) methodology has allowed the study of TL from a variety of mammalian tissues, but it has not been tested for bone marrow (BM) samples. In this study, we have examined the relationship between TL data generated by absolute qPCR versus those obtained by terminal restriction fragments (TRF) in 102 BM samples from patients with plasma cell disorders. A significant linear correlation between both methodologies was observed (p TL in hematologic disorders with substantial time and cost savings. PMID:25311116

Panero, Julieta; O'Callaghan, Nathan J; Fenech, Michael; Slavutsky, Irma

2015-02-01

426

Radioactive versus capacitance techniques for measuring soil water  

International Nuclear Information System (INIS)

A field study was conducted to compared a capacitance probe and a neutron probe for use in measuring the soil water changes and the absolute values of soil water. The study was conducted using three plots each receiving different amounts of water by a surface drip irrigation system. The 50 mm PVC access tubes were installed using a machine to auger the holes. One hole was dug using a 50 mm bulk density probe and the remaining two holes were dug using a 54 mm soil sampling tube. The two probes were calibrated to this site. The capacitance probe measured both absorption and desorption of the soil water in the semi-dry site as well as the neutron probe. The capacitance probe gave slightly higher soil water values in the semi-dry plot than the neutron probe. However, both instruments tracked the changes reasonably well. In the wet site, both probes underpredicted the actual water content, but still tracked the changes. In the dry site, which had a poorly install access tube, the capacitance probe did not accurately predict the water content or changes, while the neutron probe did. The capacitance technique will provide acceptable soil water measurements if the access tube is properly installed and appropriate calibration used. (author). 4 refs, 4 figs, 1 tab

427

Intercomparisons for the agreement of radioactivity measurement laboratories in environment  

International Nuclear Information System (INIS)

Four tests having for object the evaluation of ability of laboratories that solicit a ministerial agreement for the radioactivity measurement in environment are detailed: Water matrix, soil matrix, aerosol on filter matrix and biological matrix. For the first one test, water matrix, the categories of measures concerned are the gamma emitters radionuclides (gamma energy inferior to 100 keV), the level of activities is very low (sample: water). The second one, soil matrix, the categories of measures concerned are the uranium radioisotopes, thorium radioisotopes, radium 226 and daughter products, radium 228 and daughter products (sample: lake sediment). The third one test, aerosol on filter matrix, the categories of measures concerned are the global beta activity, the beta-gamma emitters radionuclides ( gamma energy superior to 100 keV, strontium 90 on yttrium 90 rate. For the fourth and last one test, on biological matrix the categories of measures concerned are the tritium and the strontium 90 on yttrium 90 rate (sample whole milk). The agreements are delivered by The I.R.S.N. ( Institute of radiation protection and nuclear safety). (N.C.)

428

The NIST radioactivity measurement assurance program for the radiopharmaceutical industry  

International Nuclear Information System (INIS)

The National Institute of Standards and Technology (NIST) maintains a program for the establishment and dissemination of activity measurement standards in nuclear medicine. These standards are disseminated through Standard Reference Materials (SRMs), Calibration Services, radionuclide calibrator settings, and the NIST Radioactivity Measurement Assurance Program (NRMAP, formerly the NEI/NIST MAP). The MAP for the radiopharmaceutical industry is described here. Consolidated results show that, for over 3600 comparisons, 96% of the participants' results differed from that of NIST by less than 10%, with 98% being less than 20%. Individual radionuclide results are presented from 214 to 439 comparisons, per radionuclide, for 67Ga, 90Y, 99mTc, 99Mo, 111In, 125I, 131I, and 201Tl. The percentage of participants results within 10% of NIST ranges from 88% to 98%. - Research highlights: ? NIST has maintained an MAP for the radiopharmaceutical industry since 1975. ? Participants measure sources with known, but blinded, activity and submit results. ? The schedule is chosen by a steering committee made up of participants and NIST. ? Participants submit calibrated sources for measurement by NIST during open months. ? Results are presented for over 3600 measurements of distributed sources.

429

Evaluation of the uncertainty of environmental measurements of radioactivity  

International Nuclear Information System (INIS)

Full text: The almost universal acceptance of the concept of uncertainty has led to its introduction into the ISO 17025 standard for general requirements to testing and calibration laboratories. This means that not only scientists, but also legislators, politicians, the general population - and perhaps even the press - expect to see all future results associated with an expression of their uncertainty. Results obtained by measurement of radioactivity have routinely been associated with an expression of their uncertainty, based on the so-called counting statistics. This is calculated together with the actual result on the assumption that the number of counts observed has a Poisson distribution with equal mean and variance. Most of the nuclear scientific community has therefore assumed that it already complied with the latest ISO 17025 requirements. Counting statistics, however, express only the variability observed among repeated measurements of the same sample under the same counting conditions, which is equivalent to the term repeatability used in quantitative analysis. Many other sources of uncertainty need to be taken into account before a statement of the uncertainty of the actual result can be made. As the first link in the traceability chain calibration is always an important uncertainty component in any kind of measurement. For radioactivity measurements in particular we find that counting geometry assumes the greatest importance, because it is often not possibimportance, because it is often not possible to measure a standard and a control sample under exactly the same conditions. In the case of large samples we have additional uncertainty components associated with sample heterogeneity and its influence on self-absorption and counting efficiency. In low-level environmental measurements we have an additional risk of sample contamination, but the most important contribution to uncertainty is usually the representativity of the sample being analysed. For uniform materials this can be expressed by the sampling constant, but for natural material this way of expressing uncertainty is rarely justifiable. While no established method accounting for this effect has been found, several methods to estimate its contribution to the uncertainty of measurement results will be discussed. Contemporary estimates of uncertainty must be shown to accommodate future results, and a continuous quality control based on replication of samples must be implemented to ascertain the validity of the quoted uncertainties. Illustration of a practical system that can take this effect into account will be presented

430

Multi-Segment Radius Measurement Using an Absolute Distance Meter Through a Null Assembly  

Science.gov (United States)

This system was one of the test methods considered for measuring the radius of curvature of one or more of the 18 segmented mirrors that form the 6.5 m diameter primary mirror (PM) of the James Webb Space Telescope (JWST). The assembled telescope will be tested at cryogenic temperatures in a 17-m diameter by 27-m high vacuum chamber at the Johnson Space Center. This system uses a Leica Absolute Distance Meter (ADM), at a wavelength of 780 nm, combined with beam-steering and beam-shaping optics to make a differential distance measurement between a ring mirror on the reflective null assembly and individual PM segments. The ADM is located inside the same Pressure-Tight Enclosure (PTE) that houses the test interferometer. The PTE maintains the ADM and interferometer at ambient temperature and pressure so that they are not directly exposed to the telescope s harsh cryogenic and vacuum environment. This system takes advantage of the existing achromatic objective and reflective null assembly used by the test interferometer to direct four ADM beamlets to four PM segments through an optical path that is coincident with the interferometer beam. A mask, positioned on a linear slide, contains an array of 1.25 mm diameter circular subapertures that map to each of the 18 PM segments as well as six positions around the ring mirror. A down-collimated 4 mm ADM beam simultaneously covers 4 adjacent PM segment beamlets and one ring mirror beamlet. The radius, or spacing, of all 18 segments can be measured with the addition of two orthogonally-oriented scanning pentaprisms used to steer the ADM beam to any one of six different sub-aperture configurations at the plane of the ring mirror. The interferometer beam, at a wavelength of 687 nm, and the ADM beamlets, at a wavelength of 780 nm, pass through the objective and null so that the rays are normally incident on the parabolic PM surface. After reflecting off the PM, both the ADM and interferometer beams return to their respective instruments on nearly the same path. A fifth beamlet, acting as a differential reference, reflects off a ring mirror attached to the objective and null and returns to the ADM. The spacings between the ring mirror, objective, and null are known through manufacturing tolerances as well as through an in situ null wavefront alignment of the interferometer test beam with a reflective hologram located near the caustic of the null. Since total path length between the ring mirror and PM segments is highly deterministic, any ADM-measured departures from the predicted path length can be attributed to either spacing error or radius error in the PM. It is estimated that the path length measurement between the ring mirror and a PM segment is accurate to better than 100 m. The unique features of this invention include the differential distance measuring capability and its integration into an existing cryogenic and vacuum compatible interferometric optical test.

Merle, Cormic; Wick, Eric; Hayden, Joseph

2011-01-01

431

Photoionization quantometer for absolute intensity measurements of vacuum ultraviolet and soft x-ray radiation from laser plasma  

Energy Technology Data Exchange (ETDEWEB)

Design and parameters of the photoionization quantometer are given. It is a combination of photoionization chamber with time-of-flight mass spectrometer. The quantometer is an absolute detector of radiation in the wavelength interval (100--0.1 nm) due to the fact that photoionization and electron-impact ionization cross sections of gases are used for absolute measurements. The quantometer is suitable for measurements of the number of photons in radiation pulses. The minimum number of photons detectable for a single pulse increases from 10/sup 6/ cm/sup -2/ puls/sup -1/ at 100 nm up to 10/sup 11/ cm/sup -2/ puls/sup -1/ for 0.1 nm. The quantometer has been used for vacuum ultraviolet and soft x-ray radiation measurements in the laser plasma experiment. An improved variant of the quantometer is presented which provides the absolute measurements of soft x-ray radiation for laser plasma having continuous spectrum. The inaccuracy of measurements does not exceed 25% for soft x ray.

Bobashev, S.V.; Shmaenok, L.A.

1981-01-01

432

Measurements and evaluation of absolute emission probabilities for soft photons of 153Gd, 155Eu and 169Yb  

International Nuclear Information System (INIS)

Absolute emission probabilities of Kx- and ?-rays in the energy region 40-200 keV have been obtained for 153Gd and 155Eu using measurements of emission rates by Ge, Ge(Li) and Si(Li)-detectors and of activities by a 4??-? coincidence system. The main results of our measurements and evaluation of decay data of 153Gd and 155Eu were published in 1992 and 1994. Here new experimental data concerning soft photon radiation which were obtained with a new Si(Li) spectrometer calibrated on the basis of a generalized energy response functions are presented. For the 14.06 keV ?-ray in the decay of 153Gd a value of (0.029 ± 0.003) photons per 100 disintegrations has been measured. For 155Eu the absolute emission probabilities of Kx- and 26.5, 45.3, 58.0, 60.0 ?-rays have been measured using the Si(Li) (formerly only a Ge-detector was used). A re-evaluated value of the 153Gd half-life is reported. For 169Yb the evaluation of decay data has been carried out taking into account the results of the latest measurements of absolute emission probabilities of ?-rays with energies 63.12, 109.80, 130.52 and 197.96 keV. (author)

433

Experimental and numerical study of the degradation of radioactive measurements in the filters of airborne radioactive surveillance systems  

International Nuclear Information System (INIS)

The measurement of radioactivity in the filters of airborne radioactive surveillance systems is a major metrology difficulty due to the fact that the absorption of a radiation in the filter media and the mass of aerosols accumulated distort the nuclear counting response. This thesis focuses on the determination of correction factors for the radioactivity loss in the survey filters. In a first step, radioactive filters representing the atmospheric samples have been prepared using the nuclear test bench ICARE. The experimental study on reference filters provided a database to determine correction factors for various filtration conditions. The second part proposes a new numerical method developed to determine the correction factors. It consists of coupling GeoDict for particles filtration simulations and MCNPX simulations for a transport in matter. The good agreement obtained by comparing the numerical and experimental correction factors has permitted to validate the numerical model

434

Natural Radioactivity Measurements For Some Algerian Building Materials  

International Nuclear Information System (INIS)

The objective of this work was to assess the radiation hazards associated gamma rays from building materials. The radon exhalation and uranium contents are also presented. Natural gamma rays activities of natural radionuclide represented mainly by three natural radioactive series 238U, 235U, and '232Th, and the primordial 40K in the samples of building materials consisting of soil, bricks, sand, ceramics, marble and gypsum from different areas of eastern Algeria have been measured using gamma ray spectrometry. The values of the activities of these radionuclides do not clearly reflect the radiation hazard associated with these materials. The radium equivalent (Raeq) concentration is, therefore, defined which takes into account the effectiveness of these isotopes in creating the radiation hazard. Radium equivalent activities, external and internal hazard indices (Hex and Hin) have been calculated from of the activities of 226Ra, 232Th and '40K for suitability of the materials.

435

Radioactivity measurement in spring waters of Cantabria, Spain  

International Nuclear Information System (INIS)

A study of the radioactivity existing in a high number of springs located in Cantabria, Northern Spain, was made. The spring analyzed in three sampling campaign's, And alpha and beta total activities and 226Ra and 222Rn concentrations were determined for each sample. The measuring techniques employed were gamma spectrometry with Ge detector, counting with gas flow proportional counter, and counting with ZnS(Ag) scintillating detector. Results show that springs with high radon water concentration have high values respect to the national mean. The springs with the highest radium and radon levels have thermal waters and are located on two deep fault, those have historic seismicity and seismical and geomorphological evidences of recent tectonic activity

436

Practice and experience in traceability of radioactivity measurements of environmental samples  

International Nuclear Information System (INIS)

This paper discusses some aspects on radioactivity measurement traceability and summarizes the work on quality assurance of radioactivity measurements of environmental samples in the laboratory, including transfer of standards, preparation of reference materials, and calibration of efficiency for volumse surces with Ge(Li) spectrometer. Some practical activitis regarding intercomparison of radioactivity measurements and other traceabillity-related activities are also described. Some sugestions relating to performing quality assurance are made

437

Age classification of water sediments. Measurement of isotope radioactivity  

International Nuclear Information System (INIS)

The aim of this study was to find out whether measurement of radioactivity of environmental isotopes can serve to make statements on the age of individual samples of water sediment. As a precondition, the sediment must originate form suspended matter that deposited more or less uniformly at least over certain time intervals (time windows). Samples exhibiting chaotically changing sedimentation and erosion can still not be dated at the present stage. Conclusions from measurements on environmental isotopes: The individual samples are compared with reference samples of suspended matter of the O-38?m size fraction with respect to radioactivity concentration. Then they are classified roughly in four age groups: largely new sediments (sedimentation approximately since the last high water); sediments largely dating back to around 1986; sediments largely dating back to the Nineteen Sixties, and sediments older than 1955 (including the botton ground). In addition, the class of new sediments can again be subdivided into four more finely distinguished age classes by means of beryllium-7(7Be). The samples may also contain admixtures from all other age classes. Twentyeight out of the total of 52 single samples from the Rhine, Weser, and Erft were classified as new sediment and proved capable of subclassification. The other samples exhibited no uniform sedimentation. Older fractions were predominant in this age spectrum. These fractions were again classified roughly in tctions were again classified roughly in three age classes. The 14 samples of the oldest class contain large fractions of uncontaminated botton ground. This and other similar procedures could be used for the following practical applications: The age classes can be taken into account in the valuation of chemical parameters and can thus facilitate water quality assessment, depending on the exact problem under study; sediments of apredefined age can be extracted from several individual samples taken from selected sites and analysed to clarify the initial issue of past hazardous incidents and emission and deposition situations; age calssification may also help improve sampling strategies and techniques. (orig.)

438

Measurements of whole-body radioactivity in the UK population  

International Nuclear Information System (INIS)

A national survey of whole-body radioactivity was undertaken. A mobile whole-body counter visited collaborating Medical Physics Departments and Hospitals in England and Wales. Data were also obtained from an installed whole-body counter at the West Cumberland Hospital, Whitehaven, and from a control site at Addenbrooke's Hospital, Cambridge. 1657 volunteer members of the public were measured, including 162 children. 36% of volunteers had been measured in a similar survey 2 years earlier, and showed between a two and five fold reduction in body radiocaesium. No radiocaesium was detected in 54% of people measured. Measurements showed a progressive fall over the course of the study, reaching a baseline of 0.3 Bq137Cs/gK. In 1989, the additional radiation dose incurred from radiocaesium varied from a maximum of 4.1 ?Sv in Cumbria to 1.5 ?Sv in the South East, compared with the average annual radiation dose of 2500 ?Sv due to all other causes. No other gamma-emitting radionuclides were found. Results are consistent with Chernobyl as the source of the radiocaesium detected. (author)

439

Measurement of absolute gamma ray emission probability of 1001 keV from the decay of 234mPa  

International Nuclear Information System (INIS)

In the direct ?-ray spectrometric measurements of 238U content, 1001 keV ?-ray of 234mPa is commonly used in recent years. 234mPa is the second daughter of 238U and rapidly reaches secular equilibrium with the parent nucleus. This clean peak is well resolved by high purity Ge detectors and gives more accurate indication of uranium content without requiring any self attenuation correction. Several measurements of the absolute emission probability of the 1001 keV ?-ray of 234mPa have resulted in doubts concerning the old recommended value 0.59±0.01 % obtained by a radiochemical method. Therefore, this old value is now absolute and a newly value of 0.835±0.004 % is recommended. In this study the ?-ray spectrometric measurements were carried out using the powdered U3O8 and the certified uranium samples. A new experimental value o 0.861±0.015 % for the absolute ?-ray emission probability for the 1001 keV gamma-ray of the 234mPa has been obtained. The present measured values agrees good with the most experimental results appeared in the literature and is close to the newly recommended values of 0.835±0.004 % and 0.837±0.012 % for the 1001 keV ?-ray of 234mPa

440

Testing measurement systems for finding radioactive sources - documentation of aircraft measuring missions flown in September 1988  

International Nuclear Information System (INIS)

The execution and results of test flights with helicopters for searching for or detecting radioactive materials are described, which were carried out to prepare for the crashing of the Kosmos 1900 satellite expected in October 1988. The results when overflying a Co 60 point source (1.1 GBq) at different altitudes and side distances are shown. To detect the radiation , 4''x5'' diameter NaI (Tl) detectors, large pure germanium detectors (50% relative efficiency), a liquid scintillation counter and a dose rate measuring equipment were used. Point sources of a few 100 MBq were detected in the intergral measurement of the gamma radiation with the NaI detector when flying at an altitude of 100 m and with a speed of 100 km/hour (direct overflight). This value is increased by a factor of 3 when flying over and to one side in the same conditions at a distance of 100 m. In specific nuclide measurements with the Ge-D detector, one achieves comparable results. The radioactivities which can be detected by the various systems of measurement in various flight conditions or with various flight parameters are given for some relevant nuclides. Measurements with a liquid scintillation counter and a dose rate measuring equipment (MAB 604) have not led to any satisfactory results yet. Basically, both proved suitable for looking for radioactive sources, although with the above-mentioned flight parameters only activities from some GBq upwards could be measured. (orig./HP)be measured. (orig./HP)

441

High-resolution, real-time 3D absolute coordinate measurement based on a phase-shifting method.  

Science.gov (United States)

We describe a high-resolution, real-time 3D absolute coordinate measurement system based on a phase-shifting method. It acquires 3D shape at 30 frames per second (fps), with 266K points per frame. A tiny marker is encoded in the projected fringe pattern, and detected by software from the texture image and the gamma map. Absolute 3D coordinates are obtained from the detected marker position and the calibrated system parameters. To demonstrate the performance of the system, we measure a hand moving over a depth distance of approximately 700 mm, and human faces with expressions. Applications of such a system include manufacturing, inspection, entertainment, security, medical imaging. PMID:19516395

Zhang, Song; Yau, Shing-Tung

2006-04-01

442

Radioactivity measurement in Austria 1992 and 1993. Data and evaluation  

International Nuclear Information System (INIS)

The Federal Ministry of Health and Consumer Protection is responsible for the large scale surveillance of radioactive contaminations of the Austrian territory. For this purpose on one hand an on-line measurement system has been set up, using gamma dose rate measuring devices situated in 336 locations. On the other hand, various media e.g. aerosols, precipitation, surface water and foodstuffs are being collected. Their radionuclide content is analysed in several laboratories. Additional special projects have been set up to improve the knowledge of the time dependence respectively of regional aspects of the contamination situation. The report covers the results of this surveillance for the years 1992 and 1993. The evaluation of these measurements and of other data concerning the average exposure of the Austrian population for the year 1993 is summarized in the following figure. It can be seen that the main contributions to the radiation dose are due to natural exposure pathways, among which the inhalation of indoor radon is of main importance. (Compared to the data in earlier reports due to a new evaluation of the radon risk by ICRP this dose contribution is significantly lower.) In comparison, the component due to the consequences of the Chernobyl reactor accident in 1986 onto Austrian territory during 1992 and 1993 was marginal. (author)

443

Measurements of neutron cross sections of radioactive waste nuclides  

International Nuclear Information System (INIS)

Accurate nuclear reaction cross sections of radioactive fission products and transuranic elements are required for research on nuclear transmutation methods in nuclear waste management. Important fission products in the nuclear waste management are 137Cs, 135Cs, 90Sr, 99Tc and 129I because of their large fission yields and long half-lives. The present authors have measured the neutron capture cross sections and resonance integrals of 137Cs, 90Sr and 99Tc. The purpose of this study is to measure the neutron capture cross sections and resonance integrals of nuclides, 129I and 135Cs accurately. Preliminary experiments were performed by using Rikkyo University Reactor and JRR-3 reactor at Japan Atomic Energy Research Institute (JAERI). Then, it was decided to measure the cross section and resonance inte