WorldWideScience
1

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)

2

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

3

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)

4

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

5

Radioactivity measurement  

International Nuclear Information System (INIS)

A problem with ore sorting arrangements is that radiation is difficult to measure accurately while particles are moving at speed past the detector. This is particulary so when dealing with ores such as gold ores which have weak emissions. A method of measuring radioactive emissions from moving radioactive material includes the steps of shielding the radiation detector(s) so that the angle of acceptance of the receptor surface is restricted, and further shielding the shielded portion of the detector with a second material which is less radiation emissive than the material of the first shield. This second shield is between the first shield and the detector

6

Absolute measurement method of environment radon content  

International Nuclear Information System (INIS)

A portable environment radon content device with a 40 liter decay chamber based on the method of Thomas double filter radon content absolute measurement has been developed. The correctness of the method of Thomas double filter absolute measurement has been verified by the experiments to measure the sampling gas density of radon that the theoretical density has been known. In addition, the intrinsic uncertainty of this method is also determined in the experiments. The confidence of this device is about 95%, the sensitivity is better than 0.37 Bqm-3 and the intrinsic uncertainty is less than 10%. The results show that the selected measuring and structure parameters are reasonable and the experimental methods are acceptable. In this method, the influence on the measured values from the radioactive equilibrium of radon and its daughters, the ratio of combination daughters to the total daughters and the fraction of charged particles has been excluded in the theory and experimental methods. The formula of Thomas double filter absolute measuring radon is applicable to the cylinder decay chamber, and the applicability is also verified when the diameter of exit filter is much smaller than the diameter of inlet filter

7

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)

8

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

1980-01-01

9

Measuring poverty in Portugal: an absolute approach  

OpenAIRE

The aim of this article is to measure poverty in Portugal from an absolute perspective. We estimated several absolute poverty lines and defined maximum and minimum thresholds. We applied aggregation measures to these thresholds and constructed probit models to assess the effect of some variables on poverty. The intervals obtained contain the poverty lines constructed by other approaches. We got evidence that poverty is positively correlated with the number of people in the household, with liv...

Pereira, Anto?nio Maria Seabra Moniz

2012-01-01

10

Absolute cross-sections from X-{gamma} coincidence measurements  

Energy Technology Data Exchange (ETDEWEB)

An activation technique using coincidences between characteristic X-rays and {gamma}-rays to obtain absolute cross-sections is described. This method is particularly useful in the case of nuclei that decay by electron capture. In addition to the reduction of possible contamination, an improved detection sensitivity is achieved as compared to inclusive measurements, thereby allowing the extraction of absolute fusion cross-sections in the nano-barn range. Results of this technique for {sup 6}Li+{sup 198}Pt system, at energies around the Coulomb barrier are described. Future applications with low intensity radioactive ion beams are also discussed.

Lemasson, A. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Shrivastava, A. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Navin, A. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France)], E-mail: navin@ganil.fr; Rejmund, M. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Nanal, V. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Bhattacharyya, S. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India); Chatterjee, A.; Kailas, S.; Mahata, K.; Parkar, V.V. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Pillay, R.G. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Ramachandran, K.; Rout, P.C. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2009-01-11

11

Absolute cross-sections from X-? coincidence measurements  

International Nuclear Information System (INIS)

An activation technique using coincidences between characteristic X-rays and ?-rays to obtain absolute cross-sections is described. This method is particularly useful in the case of nuclei that decay by electron capture. In addition to the reduction of possible contamination, an improved detection sensitivity is achieved as compared to inclusive measurements, thereby allowing the extraction of absolute fusion cross-sections in the nano-barn range. Results of this technique for 6Li+198Pt system, at energies around the Coulomb barrier are described. Future applications with low intensity radioactive ion beams are also discussed.

12

Absolute calibration in vivo measurement systems  

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. Absolute calibration of in vivo measurement systems will eliminate the need to generate a series of human surrogate structures (i.e., phantoms) for calibrating in vivo measurement systems. The absolute calibration of in vivo measurement systems utilizes magnetic resonance imaging (MRI) to define physiological structure, size, and composition. The MRI image provides a digitized representation of the physiological structure, which allows for any mathematical distribution of radionuclides within the body. Using Monte Carlo transport codes, the emission spectrum from the body is predicted. The in vivo measurement equipment is calibrated using the Monte Carlo code and adjusting for the intrinsic properties of the detection system. The calibration factors are verified using measurements of existing phantoms and previously obtained measurements of human volunteers. 8 refs

13

On Fourier frame of absolutely continuous measures  

CERN Document Server

Let $\\mu$ be a compactly supported absolutely continuous probability measure on ${\\Bbb R}^n$, we show that $\\mu$ admits Fourier frames if and only if its Radon-Nikodym derivative is upper and lower bounded almost everywhere on its support. As a consequence, we prove that if an equal weight absolutely continuous self-similar measure on ${\\Bbb R}^1$ admits Fourier frame, then the measure must be a characteristic function of self-similar tile. In particular, this shows for almost everywhere $1/2<\\lambda<1$, the $\\lambda$-Bernoulli convolutions cannot admit Fourier frames.

Lai, Chun-kit

2011-01-01

14

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)

15

An absolute measure for a key currency  

Science.gov (United States)

It is generally considered that the US dollar and the euro are the key currencies in the world and in Europe, respectively. However, there is no absolute general measure for a key currency. Here, we investigate the 24-hour periodicity of foreign exchange markets using a recurrence plot, and define an absolute measure for a key currency based on the strength of the periodicity. Moreover, we analyze the time evolution of this measure. The results show that the credibility of the US dollar has not decreased significantly since the Lehman shock, when the Lehman Brothers bankrupted and influenced the economic markets, and has increased even relatively better than that of the euro and that of the Japanese yen.

Oya, Shunsuke; Aihara, Kazuyuki; Hirata, Yoshito

16

Airborne measurement of radioactivity  

International Nuclear Information System (INIS)

The following is the description of an aircraft used for localizing and nuclide specific measuring of radioactive contaminated air masses. For this purpose a high-volume collector without a pump for the collection of aerosols by filters, an on board gamma spectrometry system with a high purity germanium detector, a dose ratemeter, a radon daughter monitor and for navigation a global positioning system (GPS) are used. The meteorological parameters temperature, relative humidity and relative wind speed are also determined. The cervice ceiling is 33,000 feet. The resulting measurement data are used for verifying the prognosis made by the Deutscher Wetterdienst. (orig.)

17

Measurement of absolute gravity acceleration in Firenze  

Directory of Open Access Journals (Sweden)

Full Text Available 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.

M. de Angelis

2011-01-01

18

Absolute frequency measurements on Mg+ cooling transitions  

International Nuclear Information System (INIS)

We present isotopically resolved absolute frequency measurements of both fine structure components of the 3s-3p transition in single, trapped magnesium ions. The transitions are observed in the limit of unresolved sidebands, which would lead to strongly asymmetric line shapes due to cooling and heating if only one laser were swept over the resonance. A novel spectroscopy scheme based on sympathetic cooling and spatially resolved detection allows to observe symmetric lines. The measurements contribute to astronomical searches for drifts of the fine structure constant in quasar absorption spectra and improve the accuracy over previous measurements by two orders of magnitude

19

Measurement of radioactivity  

International Nuclear Information System (INIS)

Intensive research has been going on in many countries to remove the uncertainties and to develop and perfect the methods of measuring the absolute value of the activity of a radionuclide. The importance of this research would be obvious in the context of the rapidly growing use of radioisotopes all over the world. The use of radionuclides had increased not only in regard to the variety of applications but also in respect of the quantities involved. Until recently these uses had been confined to a few scientifically advanced countries but now they were spreading to more and more countries of the world. Development in this direction was bound to continue, and this increased the importance of improving the measuring methods. The Scientific Advisory Committee of IAEA had expressed the view that it was important to attempt a synthesis of the experience in this field gained in different countries. The Vienna symposium was meant to serve that purpose

20

Absolute method of measuring magnetic susceptibility  

Science.gov (United States)

An absolute method of standardization and measurement of the magnetic susceptibility of small samples is presented which can be applied to most techniques based on the Faraday method. The fact that the susceptibility is a function of the area under the curve of sample displacement versus distance of the magnet from the sample, offers a simple method of measuring the susceptibility without recourse to a standard sample. Typical results on a few substances are compared with reported values, and an error of less than 2% can be achieved. ?? 1959 The American Institute of Physics.

Thorpe, A.; Senftle, F.E.

1959-01-01

21

On Absolute Measurements of ?-Emitting Radionuclides  

International Nuclear Information System (INIS)

4 ? GM detectors are described and some of their characteristics presented. The absence of spurious pulses is shown by the measurement of the rate of arrival of intervals between pulses. Some problems related to the foil absorption and source absorption are considered using Sr90 and Y90. Aiming at correcting the counting losses in the foil and in a certain extent also the source absorption an experimental method which uses paired sources is presented. The preparation of standards of Bi210 (RaE) is described. A note is presented on the problem of foil absorption losses in scintillation absolute counting. (author)

22

Measured and modelled absolute gravity in Greenland  

Science.gov (United States)

Present day changes in the ice volume in glaciated areas like Greenland will change the load on the Earth and to this change the lithosphere will respond elastically. The Earth also responds to changes in the ice volume over a millennial time scale. This response is due to the viscous properties of the mantle and is known as Glaical Isostatic Adjustment (GIA). Both signals are present in GPS and absolute gravity (AG) measurements and they will give an uncertainty in mass balance estimates calculated from these data types. It is possible to separate the two signals if both gravity and Global Positioning System (GPS) time series are available. DTU Space acquired an A10 absolute gravimeter in 2008. One purpose of this instrument is to establish AG time series in Greenland and the first measurements were conducted in 2009. Since then are 18 different Greenland GPS Network (GNET) stations visited and six of these are visited more then once. The gravity signal consists of three signals; the elastic signal, the viscous signal and the direct attraction from the ice masses. All of these signals can be modelled using various techniques. The viscous signal is modelled by solving the Sea Level Equation with an appropriate ice history and Earth model. The free code SELEN is used for this. The elastic signal is modelled as a convolution of the elastic Greens function for gravity and a model of present day ice mass changes. The direct attraction is the same as the Newtonian attraction and is calculated as this. Here we will present the preliminary results of the AG measurements in Greenland. We will also present modelled estimates of the direct attraction, the elastic and the viscous signals.

Nielsen, E.; Forsberg, R.; Strykowski, G.

2012-12-01

23

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;

24

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

25

Measurement of radioactivity in rain  

International Nuclear Information System (INIS)

The report gives a description of an ion-exchange surveillance- sampler for routine measurements of radioactivity in rain, and how the measurements are performed. Using the nuclides 85Sr, 131I and 137Cs as tracers, experiments have been performed to determine the distribution of radioactivity in the ion-exchange column and the effectiveness of the column as a function of elutriation rate and temperature

26

Radioactivity  

International Nuclear Information System (INIS)

This educative booklet give a general overview of radioactivity: history, structure of matter, radiations, radioactivity law, origin of radioactivity, radioactivity uses, radioprotection and measurement units. (J.S.)

27

Absolute measurement of ? activities and application to the determination of neutronic densities  

International Nuclear Information System (INIS)

M. Berthelot, to my entrance to the ''Commissariat a l 'Energie Atomique'', proposed me to study the absolute measurement of neutron densities. Very quickly the problem of the absolute activity of ? sources became the central object of this work. In a first part, we will develop the methods of absolute determination for ? activities. The use of a 4? counter permits to get the absolute activity of all beta radioactive source, susceptible to be put as thin leaf and of period superior than some minutes. The method is independent of the spectra of the measured radioelement. we will describe in the second part some applications which use neutron densities measurement, neutron sources intensities and ratio of cross sections of capture of thermal neutrons. (M.B.)

28

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)

29

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

30

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 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

31

MLU and IPSyn measuring absolute complexity  

OpenAIRE

This article compares the results of Mean Length of Utterance (MLU) and Index of Productive Syntax (IPSyn) with the structural complexity of spontaneous utterances produced by 30-month-old Finnish children in a semi-structured playing situation. The comparison was carried out in order to determine the aspects of structural complexity which can be detected with MLU and IPSyn. This research adopts the frameworks of absolute complexity together with a multidimensional view of utterance structure...

Lea Nieminen

2009-01-01

32

Measurement of the absolute luminosity with the ALEPH detector  

Science.gov (United States)

We report on the absolute luminosity measurement performed with the ALEPH detector at LEP. The systematic errors of the measurements in 1990 are estimated to be 0.6% (experimental) and 0.3% (theoretical).

Decamp, D.; Deschizeaux, B.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Alemany, R.; Crespo, J. M.; Delfino, M.; Fernandez, E.; Gaitan, V.; Garrido, Ll.; Mir, Ll. M.; Pacheco, A.; Catanesi, M. G.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Maggi, M.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Gao, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Lou, J.; Qiao, C.; Ruan, T.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhao, W.; Atwood, W. B.; Bauerdick, L. A. T.; Bird, F.; Blucher, E.; Bonvicini, G.; Bossi, F.; Boudreau, J.; Brown, D.; Burnett, T. H.; Drevermann, H.; Forty, R. W.; Grab, C.; Hagelberg, R.; Haywood, S.; Hilgart, J.; Jost, B.; Kasemann, M.; Knobloch, J.; Lacourt, A.; Lançon, E.; Lehraus, I.; Lohse, T.; Lusiani, A.; Marchioro, A.; Martinez, M.; Mato, P.; Menary, S.; Minten, A.; Miotto, A.; Miquel, R.; Moser, H.-G.; Nash, J.; Palazzi, P.; Ranjard, F.; Redlinger, G.; Roth, A.; Rothberg, J.; Rotscheidt, H.; Saich, M.; Schlatter, D.; Schmelling, M.; Takashima, M.; Tejessy, W.; Wachsmuth, H.; Wasserbaech, S.; Wiedenmann, W.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; Bencheikh, A. M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Harvey, J.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Proriol, J.; Prulhière, F.; Stimpfl, G.; Bertelsen, H.; Hansen, F.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Lindhal, A.; Møllerud, R.; Nilsson, B. S.; Petersen, G.; Efthymiopoulos, I.; Simopoulou, E.; Vayaki, A.; Badier, J.; Blondel, A.; Bonneaud, G.; Bourotte, J.; Braems, F.; Brient, J. C.; Fouque, G.; Gamess, A.; Guirlet, R.; Orteu, S.; Rosowsky, A.; Rougé, A.; Rumpf, M.; Tanaka, R.; Videau, H.; Candlin, D. J.; Veitch, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Lannutti, J.; Levinthal, D.; Mermikides, M.; Sawyer, L.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Zografou, P.; Altoon, B.; Boyle, O.; Halley, A. W.; Ten Have, I.; Hearns, J. L.; Lynch, J. G.; Morton, W. T.; Raine, C.; Scarr, J. M.; Smith, K.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geiges, R.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Belk, A. T.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Dornan, P. J.; Dugeay, S.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Patton, S. J.; Payne, D. G.; Phillips, M. J.; Sedgbeer, J. K.; Taylor, G.; Tomalin, I. R.; Wright, A. G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Keemer, N. R.; Nuttall, M.; Patel, A.; Rowlingson, B. S.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Barczewski, T.; Kleinknecht, K.; Raab, J.; Renk, B.; Roehn, S.; Sander, H.-G.; Schmidt, H.; Steeg, F.; Walther, S. M.; Wolf, B.; Aubert, J.-J.; Benchouk, C.; Bernard, V.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Papalexiou, S.; Payre, P.; Pietrzyk, B.; Qian, Z.; Rousseau, D.; Schwemling, P.; Talby, M.; Becker, H.; Blum, W.; Cattaneo, P.; Cowan, G.; Dehning, B.; Dietl, H.; Dydak, F.; Fernandez-Bosman, M.; Hansl-Kozanecka, T.; Jahn, A.; Kozanecki, W.; Lange, E.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Pan, Y.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Stierlin, U.; Denis, R. St.; Thomas, J.; Wolf, G.; Bertin, V.; Boucrot, J.; Callot, O.; Chen, X.; Cordier, A.; Davier, M.; Ganis, G.; Grivaz, J.-F.; Heusse, Ph.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Zomer, F.; Abbaneo, D.; Amendolia, S. R.; Bagliesi, G.; Batignani, G.; Bosisio, L.; Bottigli, U.; Bradaschia, C.; Carpinelli, M.; Ciocci, M. A.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Focardi, E.; Forti, F.; Gatto, C.; Giassi, A.; Giorgi, M. A.; Ligabue, F.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Sanguinetti, G.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Carter, J. M.; Green, M. G.; March, P. V.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; Thomas, R. M.; West, L. R.; Wildish, T.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Edwards, M.; Fisher, S. M.; Jones, T. J.; Norton, P. R.; Salmon, D. P.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Klopfenstein, C.; Locci, E.; Loucatos, S.; Monnier, E.; Perez, P.; Perlas, J. A.; Perrier, F.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.

1992-09-01

33

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

34

Measuring the absolute magnetic field using high-Tc SQUID  

International Nuclear Information System (INIS)

SQUID normally can only measure the change of magnetic field instead of the absolute value of magnetic field. Using a compensation method, a mobile SQUID, which could keep locked when moving in the earth's magnetic field, was developed. Using the mobile SQUID, it was possible to measure the absolute magnetic field. The absolute value of magnetic field could be calculated from the change of the compensation output when changing the direction of the SQUID in a magnetic field. Using this method and the mobile SQUID, we successfully measured the earth's magnetic field in our laboratory

35

Statistical aspects in radioactivity measurements  

International Nuclear Information System (INIS)

This report contains a summary of basic concepts and formulae important for the treatment of errors and for calculating lower limits of detection in radioactivity measurements. Special attention has been paid to practical application and examples which are of interest for scientists working in this field. (orig./HP)

36

Absolute measurements of fast neutrons using yttrium.  

Science.gov (United States)

Yttrium is presented as an absolute neutron detector for pulsed neutron sources. It has high sensitivity for detecting fast neutrons. Yttrium has the property of generating a monoenergetic secondary radiation in the form of a 909 keV gamma-ray caused by inelastic neutron interaction. It was calibrated numerically using MCNPX and does not need periodic recalibration. The total yttrium efficiency for detecting 2.45 MeV neutrons was determined to be f(n) approximately 4.1x10(-4) with an uncertainty of about 0.27%. The yttrium detector was employed in the NX2 plasma focus experiments and showed the neutron yield of the order of 10(8) neutrons per discharge. PMID:20815606

Roshan, M V; Springham, S V; Rawat, R S; Lee, P; Krishnan, M

2010-08-01

37

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.)

38

Absolute quantum yield measurement of powder samples.  

Science.gov (United States)

Measurement of fluorescence quantum yield has become an important tool in the search for new solutions in the development, evaluation, quality control and research of illumination, AV equipment, organic EL material, films, filters and fluorescent probes for bio-industry. Quantum yield is calculated as the ratio of the number of photons absorbed, to the number of photons emitted by a material. The higher the quantum yield, the better the efficiency of the fluorescent material. For the measurements featured in this video, we will use the Hitachi F-7000 fluorescence spectrophotometer equipped with the Quantum Yield measuring accessory and Report Generator program. All the information provided applies to this system. Measurement of quantum yield in powder samples is performed following these steps: 1. Generation of instrument correction factors for the excitation and emission monochromators. This is an important requirement for the correct measurement of quantum yield. It has been performed in advance for the full measurement range of the instrument and will not be shown in this video due to time limitations. 2. Measurement of integrating sphere correction factors. The purpose of this step is to take into consideration reflectivity characteristics of the integrating sphere used for the measurements. 3. Reference and Sample measurement using direct excitation and indirect excitation. 4. Quantum Yield calculation using Direct and Indirect excitation. Direct excitation is when the sample is facing directly the excitation beam, which would be the normal measurement setup. However, because we use an integrating sphere, a portion of the emitted photons resulting from the sample fluorescence are reflected by the integrating sphere and will re-excite the sample, so we need to take into consideration indirect excitation. This is accomplished by measuring the sample placed in the port facing the emission monochromator, calculating indirect quantum yield and correcting the direct quantum yield calculation. 5. Corrected quantum yield calculation. 6. Chromaticity coordinates calculation using Report Generator program. The Hitachi F-7000 Quantum Yield Measurement System offer advantages for this application, as follows: High sensitivity (S/N ratio 800 or better RMS). Signal is the Raman band of water measured under the following conditions: Ex wavelength 350 nm, band pass Ex and Em 5 nm, response 2 sec), noise is measured at the maximum of the Raman peak. High sensitivity allows measurement of samples even with low quantum yield. Using this system we have measured quantum yields as low as 0.1 for a sample of salicylic acid and as high as 0.8 for a sample of magnesium tungstate. Highly accurate measurement with a dynamic range of 6 orders of magnitude allows for measurements of both sharp scattering peaks with high intensity, as well as broad fluorescence peaks of low intensity under the same conditions. High measuring throughput and reduced light exposure to the sample, due to a high scanning speed of up to 60,000 nm/minute and automatic shutter function. Measurement of quantum yield over a wide wavelength range from 240 to 800 nm. Accurate quantum yield measurements are the result of collecting instrument spectral response and integrating sphere correction factors before measuring the sample. Large selection of calculated parameters provided by dedicated and easy to use software. During this video we will measure sodium salicylate in powder form which is known to have a quantum yield value of 0.4 to 0.5. PMID:22617474

Moreno, Luis A

2012-01-01

39

Measurement of absolute gravity acceleration in Firenze  

OpenAIRE

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 ...

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

2011-01-01

40

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

41

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

42

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

43

On the Absolute Continuity of the Blackwell Measure  

Science.gov (United States)

In 1957, Blackwell expressed the entropy of hidden Markov chains using a measure which can be characterised as an invariant measure for an iterated function system with place-dependent weights. This measure, called the Blackwell measure, plays a central role in understanding the entropy rate and other important characteristics of fundamental models in information theory. We show that for a suitable set of parameter values the Blackwell measure is absolutely continuous for almost every parameter in the case of binary symmetric channels.

Bárány, Balázs; Kolossváry, István

2015-04-01

44

ABSOLUTE PHOTODETACHMENT CROSS-SECTION MEASUREMENTS FOR HYDROCARBON CHAIN ANIONS  

Energy Technology Data Exchange (ETDEWEB)

Absolute photodetachment cross sections have been measured for the hydrocarbon chain anions C{sub n}H{sup -}, n = 2, 4, and 6, which are relevant for an understanding of molecular clouds in the interstellar medium. Data have been obtained for different photon energies within approximately 1 eV of the detachment threshold. With our recently developed method we have achieved a precision of better than 25% on these absolute cross sections. The experiments have been carried out by means of photodetachment tomography of the mass-selected molecular anions in a multipole radio-frequency ion trap. The measured absolute cross sections are in accordance with the empirical scaling law of Millar et al. and have allowed us to determine its free parameters. These results are important for predicting the photostability and thus the abundance of carbon chain anions in planetary atmospheres, in circumstellar envelopes, and in photon-dominated regions of interstellar molecular clouds.

Best, T.; Otto, R.; Wester, R. [Institut fuer Ionenphysik und Angewandte Physik, Universitaet Innsbruck, A-6020 Innsbruck (Austria); Trippel, S.; Hlavenka, P.; Von Zastrow, A.; Eisenbach, S.; Jezouin, S. [Physikalisches Institut, Universitaet Freiburg, 79104 Freiburg (Germany); Vigren, E.; Hamberg, M.; Geppert, W. D., E-mail: roland.wester@uibk.ac.at [Molecular Physics Division, Stockholm University, Stockholm (Sweden)

2011-12-01

45

A cryogenic radiometer for absolute neutron rate measurement  

International Nuclear Information System (INIS)

We detail the design and operation of an electrical substitution radiometer, which measures the absolute fluence of thermal neutron beams based on neutron absorption in a 6Li-rich metallic alloy. We demonstrate that the device possesses a linear response to electrical power in the 50-500 nW range with better than 0.1% absolute accuracy and negligible zero offset. We show the response of the radiometer to a 3 meV neutron beam. We compare the noise of the radiometer to the noise observed upstream in a thin rate monitor and show that the radiometer noise is understood quantitatively. We establish that the radiometer measures neutron rates above 105 s-1 to an absolute accuracy of 0.1%

46

Europe's Other Poverty Measures: Absolute Thresholds Underlying Social Assistance  

Science.gov (United States)

The first thing many learn about international poverty measurement is that European nations apply a "relative" poverty threshold and that they also do a better job of reducing poverty. Unlike the European model, the "absolute" U.S. poverty threshold does not increase in real value when the nation's standard of living rises, even though it is…

Bavier, Richard

2009-01-01

47

Measurement of absolute electron density with a plasma impedance probe  

International Nuclear Information System (INIS)

A small spherical probe is used in conjunction with a network analyzer to determine the impedance of the probe-plasma system over a wide frequency range. Impedance curves are in good agreement with accepted circuit models with plasma-sheath and electron plasma frequency resonances easily identifiable. Clear transitions between capacitive and inductive modes as predicted by the model are identified. Sheath thickness and absolute electron density are determined from the location of these transitions. The absolute electron density indicated by the location of the impedance resonance is compared to measurements using the plasma oscillation method

48

Radioactive waste measuring technique. Low level radioactive waste  

International Nuclear Information System (INIS)

The operation of Rokkasho Low Level Radioactive Waste Burial Center was commenced in December 1992, and transport of homogeneous solidified body drums to this center was started. It is mandatory that low level radioactive waste drums are checked before bring-out to assure that they conform to the burial criteria of the nation. The items of this check are seven items. In these items, radioactivity measurement is explained below. 1. Radioactivity concentration measurement. The radio of the gamma-ray discharge nuclide is measured using a high purity Ge semiconductor detector, while the gross gamma-ray dose is measured simultaneously using a plastic scintillation detector. The radioactivity of the representative nuclide is calculated from the detected nuclide component ratio and the gross gamma-ray counting rate, and in addition, the radioactivity concentration is calculated from the involved total radioactivity and weight measured value included in the waste drum analysis data. Specification. Nuclide to be measured: Co-60, Cs-137, etc. Detection lower limit value: 3.7x10-1 Bq/g. 2. Surface contamination density and dose equivalent measurement. After the surface substance was sampled using a wiping material, measurement of this wiping material is taken using a radiation detector. For surface dose equivalent measurement, a radiation detector is directly mounted to a wiping material mounting arm, and the gamma-ray dose is measured simultaneously during wiping actions. Specification. Detection lower limit: 3.7x10-1 Bq/cm2. Surface dose rate: 10-3 mSv/h - 10 mSv/h. (author)

49

Measurement of Radioactivity in Some Croatian Regions  

International Nuclear Information System (INIS)

Full text: After Government of Canada expressed its suspicion that Canadian soldiers who were included in UNPROFOR mission in Croatia were exposed to increased radioactivity and possible some chemical influences, a large action of measuring and sampling was undertaken. Canadian and Croatian experts were working together and a very large number of samples was collected. Measurements of alpha, beta and gamma radioactivity on terrain, as well as later analysis of samples showed no increased radioactivity or any other signs of radioactive contamination. The conclusion is that any possible diseases of Canadian soldiers can not originate from radiation or radioactive contamination in Croatia. (author)

50

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)

51

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

52

Absolute measurement of square flats with Legendre polynomial fitting method  

Science.gov (United States)

Zernike Polynomial fitting method is an effective way to reconstruct absolute surface for three-flat test. However, the Zernike circle polynomials are not orthogonal over the circular area, hence they are not suitable for square flat. We present an absolute testing of a square flat with Legendre polynomial fitting method, which relies on calculating the coefficients of the Legendre terms by least-square fitting method. To obtain the three-dimensional surface data, one additional measurement that rotate the test flat through 90° should be introduced. The formulas are derived theoretically in detail, and validity has been proved by simulated experiment. Vertical profiles of the three surfaces are compared with the measurement results obtained by three-flat test. Good agreement validates our method.

Gao, Bo; Li, Qiang; He, Yuhang; Chai, Liqun; Wei, Xiaohong

2014-12-01

53

Measuring absolute spectral radiance using an Erbium Doped Fibre Amplifier  

CERN Document Server

We describe a method to measure the spectral radiance of a source in an absolute way without the need of a reference. Here we give the necessary detail to allow for the device to be reproduced from standard fiber-optic components. The device is suited for fiber-optic applications at telecom wavelengths and calibration of powermeters and spectrometers at light levels from 1nW to 1uW.

Sanguinetti, Bruno; Monteiro, Fernando; Gisin, Nicolas; Zbinden, Hugo

2012-01-01

54

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

55

Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis  

Energy Technology Data Exchange (ETDEWEB)

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 successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

Sannibale, F.; /LBL, Berkeley; Stupakov, G.V.; /SLAC; Zolotorev, M.S.; /LBL, Berkeley; Filippetto, D.; /INFN, Rome; Jagerhofer, L.; /Vienna, Tech. U.

2009-12-09

56

Absolute bunch length measurements by incoherent radiation fluctuation analysis  

Energy Technology Data Exchange (ETDEWEB)

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 successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

Sannibale, Fernando; Stupakov, Gennady; Zolotorev, Max; Filippetto, Daniele; Jagerhofer, Lukas

2008-09-29

57

Absolute and relative deprivation and the measurement of poverty  

OpenAIRE

This paper develops the link between poverty and inequality by focussing on a class of poverty indices (some of them well-known) which aggregate normative concerns for absolute and relative deprivation. The indices are distinguished by a parameter that captures the ethical sensitivity of poverty measurement to ``exclusion'' or ``relative-deprivation'' aversion. We also show how the indices can be readily used to predict the impact of growth on poverty. An illustration using LIS data finds tha...

Duclos, Jean-yves; Gregoire, Philippe

2006-01-01

58

Precision Absolute Beam Current Measurement of Low Power Electron Beam  

Energy Technology Data Exchange (ETDEWEB)

Precise measurements of low power CW electron beam current for the Jefferson Lab Nuclear Physics program have been performed using a Tungsten calorimeter. This paper describes the rationale for the choice of the calorimeter technique, as well as the design and calibration of the device. The calorimeter is in use presently to provide a 1% absolute current measurement of CW electron beam with 50 to 500 nA of average beam current and 1-3 GeV beam energy. Results from these recent measurements will also be presented.

Ali, M. M.; Bevins, M. E.; Degtiarenko, P.; Freyberger, A.; Krafft, G. A.

2012-11-01

59

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 and perfo...

Fenech Michael; O'Callaghan Nathan J

2011-01-01

60

Precision Absolute Beam Current Measurement of Low Power Electron Beam  

International Nuclear Information System (INIS)

Precise measurements of low power CW electron beam current for the Jefferson Lab Nuclear Physics program have been performed using a Tungsten calorimeter. This paper describes the rationale for the choice of the calorimeter technique, as well as the design and calibration of the device. The calorimeter is in use presently to provide a 1% absolute current measurement of CW electron beam with 50 to 500 nA of average beam current and 1-3 GeV beam energy. Results from these recent measurements will also be presented

61

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.)

62

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

63

Measurement of the absolute flux of cosmic-ray electrons  

International Nuclear Information System (INIS)

The absolute flux of cosmic-ray electrons has been measured using a balloon-borne superconducting magnet spectrometer. The instrument consisted of a gas Cerenkov detector, a momentum spectrometer, and a lead-scintillator shower counter. The flux of electrons in the interstellar medium was determined by correcting the observed flux for energy loss in the atmosphere and the payload and for solar modulation. The flight was made at an average atmospheric depth of 5.8 g cm-2, and the solar modulation was taken to be 300 MeV. The flux in the interstellar medium was found to be 367E/sup() -3.15plus-or-minus0.2/ e- m-2 sr-1 s-1 GeV-1 in the energy interval 4.5-63.5 GeV. The uncertainty in the absolute flux is 10%. The result has been validated by the use of data from a second balloon flight, the use of alternate selection criteria, and simultaneous measurement of other absolute fluxes

64

Measurement of the absolute flux of cosmic-ray electrons  

Energy Technology Data Exchange (ETDEWEB)

The absolute flux of cosmic-ray electrons has been measured using a balloon-borne superconducting magnet spectrometer. The instrument consisted of a gas Cerenkov detector, a momentum spectrometer, and a lead-scintillator shower counter. The flux of electrons in the interstellar medium was determined by correcting the observed flux for energy loss in the atmosphere and the payload and for solar modulation. The flight was made at an average atmospheric depth of 5.8 g cm/sup -2/, and the solar modulation was taken to be 300 MeV. The flux in the interstellar medium was found to be 367E/sup() -3.15plus-or-minus0.2/ e/sup -/ m/sup -2/ sr/sup -1/ s/sup -1/ GeV/sup -1/ in the energy interval 4.5-63.5 GeV. The uncertainty in the absolute flux is 10%. The result has been validated by the use of data from a second balloon flight, the use of alternate selection criteria, and simultaneous measurement of other absolute fluxes.

Golden, R.L.; Mauger, B.G.; Badhwar, G.D.; Daniel, R.R.; Lacy, J.L.; Stephens, S.A.; Zipse, J.E.

1984-12-15

65

Carbon clusters for absolute mass measurements at ISOLTRAP  

International Nuclear Information System (INIS)

The cyclotron frequencies of singly charged carbon clusters Cn+ (n?2) were measured with the Penning-trap mass spectrometer ISOLTRAP at ISOLDE/CERN. The present limit of mass accuracy ?m/m=1.2.10-8 and the extent of the mass-dependent systematic shift (?m/m)sys=1.7(0.6).10-10/u.(m-m ref) of the setup were investigated for the first time. In addition, absolute mass measurements by use of pure clusters of the most abundant carbon isotope 12C are now possible at ISOLTRAP. (orig.)

66

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

67

Deflectometric systems for absolute flatness measurements at PTB  

International Nuclear Information System (INIS)

Recently, two new scanning deflectometric flatness reference (DFR) measurement systems were installed at the Physikalisch-Technische Bundesanstalt. These instruments are aimed at measurements of the absolute flatness of optical surfaces with sub-nanometre uncertainties. System 1 is mainly designed for horizontal specimens with sizes up to 1 m and weights up to 120 kg. The other setup, i.e. system 2, is designed for vertical specimens. The two DFR systems use three different deflectometric procedures, which are based on scanning a pentaprism or the so-called double mirror unit (DMU) across the specimen. These 90° beam deflectors eliminate—to a great extent—residual guidance errors of the scanning stages, which is required to attain topography measurements with sub-nanometre uncertainty. The setups of the two new systems, the principles of the three different measurement modes, the alignment procedures, simulation results and first measurements are presented. (paper)

68

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

69

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

70

3D measurement of absolute radiation dose in grid therapy  

International Nuclear Information System (INIS)

Spatially fractionated radiotherapy through a grid is a concept which has a long history and was routinely used in orthovoltage radiation therapy in the middle of last century to minimize damage to the skin and subcutaneous tissue. With the advent of megavoltage radiotherapy and its skin sparing effects the use of grids in radiotherapy declined in the 1970s. However there has recently been a revival of the technique for use in palliative treatments with a single fraction of 10 to 20 Gy. In this work the absolute 3D dose distribution in a grid irradiation is measured for photons using a combination of film and gel dosimetry

71

Absolute efficiency measurements with the 10B based Jalousie detector  

International Nuclear Information System (INIS)

The 10B based Jalousie detector is a replacement for 3He counter tubes, which are nowadays less affordable for large area detectors due to the 3He crisis. In this paper we investigate and verify the performance of the new 10B based detector concept and its adoption for the POWTEX diffractometer, which is designed for the detection of thermal neutrons with predicted detection efficiencies of 75–50% for neutron energies of 10–100 meV, respectively. The predicted detection efficiency has been verified by absolute measurements using neutrons with a wavelength of 1.17 ? (59 meV)

72

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)

73

An Alpha-Gamma Counter for Absolute Neutron Flux Measurement  

Science.gov (United States)

An alpha-gamma counter was used to measure the absolute neutron flux of a monochromatic cold neutron beam to sub-0.1,% precision. Simultaneously, the counter was used to calibrate a thin neutron flux monitor based on neutron absorption on ^6Li to the same precision. This monitor was used in the most precise beam-based measurement of the neutron lifetime, where the limiting systematic effect was the uncertainty in the neutron counting efficiency (0.3,%). The counter uses a thick target of ^10B-enriched boron carbide to completely absorb the beam. The rate of absorbed neutrons is determined by counting 478 keV gamma rays from neutron capture on ^10B with calibrated high-purity germanium detectors. The calibration results and the implications for the neutron lifetime will be discussed.

Yue, A.; Greene, G.; Dewey, M.; Gilliam, D.; Nico, J.; Laptev, A.

2012-03-01

74

Absolute solar flux measurement shortward of 575 A-circle  

International Nuclear Information System (INIS)

A rare-gas ionization chamber was used to obtain an accurate measurement of the absolute solar EUV flux in the 50- to 575-A-circle region. The instrument, operating in total and near-total absorption, was flown on a solar-pointing sounding rocket on August 16, 1983. For the day of the flight the solar activity indices were F/sub 10.7/ = 132.1 and R/sub I/ = 80, and the integrated solar irradiance at the earth, corrected for atmospheric absorption, was found to be 4.31 +- 0.31 x 1010 photons cm-2 s-1. Almost exactly a year earlier (August 10, 1982) the same instrument measured an integrated solar flux of 5.71 +- 0.42 x 1010 photons cm-2 s-1 during a time of enhanced solar activity (F/sub 10.7/ = 209.5 and R/sub I/ = 155)

75

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)

76

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)

77

Laser interferometry method for absolute measurement of the acceleration of gravity  

Science.gov (United States)

Gravimeter permits more accurate and precise absolute measurement of g without reference to Potsdam values as absolute standards. Device is basically Michelson laser beam interferometer in which one arm is mass fitted with corner cube reflector.

Hudson, O. K.

1971-01-01

78

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

79

Environmental radioactivity measurements in the United Kingdom  

Energy Technology Data Exchange (ETDEWEB)

An account is given of current work in the field of radioactivity measurements in the marine and terrestrial environments of the United Kingdom. Reference is made to the increasing need for quality assurance and to the role of measurement standards and traceability. 20 references.

Christmas, P.

1984-01-01

80

Measuring the absolute quantum efficiency of luminescent materials  

International Nuclear Information System (INIS)

A measurement system and mathematical procedure are developed for determining the absolute quantum efficiency (QE), of luminescent materials. This technique, based on absorption of diffuse light within an integrating sphere, is applied to fluorescent laser dyes and conventional phosphor powders. The system described is tested for excitation in the near-UV and blue regions, but can be applied to higher energy excitation (UV), as well as lower energy excitation in the visible to near-IR, with the appropriate photodetectors and optical filters. The system was tested on both liquid and solid samples such as Coumarin 500 (CM500) dye in methanol and ethyl acetate; Rhodamine 6G in ethanol; and a variety of powder phosphors. The QE of quinine sulfate dihydrate solution (5x10-3 M in 0.1 N H2SO4), a NIST fluorescence standard, was found to be in good agreement with the NIST value under 390 nm excitation. The accuracy of this measurement technique is acceptable for samples with absorption cross sections greater than ?6 mm2

81

Measuring the absolute quantum efficiency of luminescent materials  

Energy Technology Data Exchange (ETDEWEB)

A measurement system and mathematical procedure are developed for determining the absolute quantum efficiency (QE), of luminescent materials. This technique, based on absorption of diffuse light within an integrating sphere, is applied to fluorescent laser dyes and conventional phosphor powders. The system described is tested for excitation in the near-UV and blue regions, but can be applied to higher energy excitation (UV), as well as lower energy excitation in the visible to near-IR, with the appropriate photodetectors and optical filters. The system was tested on both liquid and solid samples such as Coumarin 500 (CM500) dye in methanol and ethyl acetate; Rhodamine 6G in ethanol; and a variety of powder phosphors. The QE of quinine sulfate dihydrate solution (5x10{sup -3} M in 0.1 N H{sub 2}SO{sub 4}), a NIST fluorescence standard, was found to be in good agreement with the NIST value under 390 nm excitation. The accuracy of this measurement technique is acceptable for samples with absorption cross sections greater than {approx}6 mm{sup 2}.

Rohwer, Lauren Shea [Sandia National Laboratories, P.O. Box 5800, MS-0892, Albuquerque, NM 87185-0892 (United States)]. E-mail: leshea@sandia.gov; Martin, James E. [Sandia National Laboratories, P.O. Box 5800, MS-0892, Albuquerque, NM 87185-0892 (United States)

2005-11-15

82

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 approximately 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.

Rastello, Maria Luisa; Miraldi, Elio; Pisoni, Paolo

1996-08-01

83

Environmental radioactivity: measurements and their meaning  

International Nuclear Information System (INIS)

Radioactivity in the environment includes naturally occurring as well as man-made radionuclides. Meaningful estimates of their hazard to health require much care in obtaining representative environmental samples, appropriate sample preparation as well as proper calibration of the measuring system. Any harm from the low absorbed doses of ionizing radiation typically received from environmental radioactivity would only occur after a latent period of several years. Of these, cancer induction is considered to be the most important. Risk factors have been derived by a number of internationally recognized organizations, but there are difficulties in extrapolating from observations at a high dose and dose rate and for the lifetime of exposed populations. Examples of measurement of 222Ra, 90Sr, 125I, 226Ra, 129I and 137Cs in the environment are given. Harmful effects from environmental radioactivity have mostly been indistinguishable above natural incidence. (author)

84

Embedded north-seeker for automatic absolute magnetic DI measurements  

Science.gov (United States)

In magnetic observatory Earth magnetic field is recorded with a resolution of 0.1nT for 1min sampling (new standards impose 1pT for 1s sampling). The method universally adopted for measuring it is a combination of three instruments. Vectorial magnetometer (variometer) records variations of the three components around a reference value or a baseline. A proton or an overhauser magnetometer is an absolute instrument able to measure the modulus of the field and used to determine the F component baseline of the variometer. The declination and inclination baselines require a manual procedure to be computed. An operator manipulates a non-magnetic theodolite (also called a DIFlux) to measure the D and I angles in different configurations with a resolution of a few arcsec. The AutoDIF is a non-magnetic automatic DIFlux using the same protocol as the manual procedure. The declination defined according to the true north is determined by means of a target pointing system. Even if the technique is fast and accurate, it becomes problematic in case of unmanned deployment. In particular the area between the target and the DIFlux is out of control. Snow storm, fog, vegetation or condensation on windows are examples of perturbation preventing for finding the target. It is obvious in case of (future) seafloor observatories. A FOG based north-seeker has been implemented and mounted on the AutoDIF. The first results using a low cost gyro don't meet the Intermagnet specifications yet but are however hopeful. A 0.1° standard deviation has been reached and statistically reduced to 0.01° after less than two days in laboratory. The magnetic disturbance of the sensor is taken into account and compensated by the measurement protocol.

Gonsette, Alexandre; Rasson, Jean

2014-05-01

85

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)

86

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)

87

ATLAS ALFA-measuring absolute luminosity with scintillating fibres  

International Nuclear Information System (INIS)

ALFA is a high-precision scintillating fibre tracking detector under construction for the absolute determination of the LHC luminosity at the ATLAS interaction point. This detector, mounted in so-called Roman Pots, will track protons elastically scattered under ?rad angles at IP1.In total there are four pairs of vertically arranged detector modules which approach the LHC beam axis to mm distance. Each detector module consists of ten layers of two times 64 scintillating fibres each (U and V planes). The fibres are coupled to 64 channels Multi-Anodes PhotoMultipliers Tubes read out by compact front-end electronics. Each detector module is complemented by so-called overlap detectors: Three layers of two times 30 scintillating fibres which will be used to measure the relative positioning of two vertically arranged main detectors. The total number of channels is about 15000. Conventional plastic scintillator tiles are mounted in front of the fibre detectors and will serve as trigger counter. The extremely restricted space inside the pots makes the coupling to the read out devices very challenging. Several technologies have been tested in a beam at DESY and a cosmic-ray setup at CERN. A possible upgrade of the photo detection could consist in the replacement of the PMT by Geiger-mode avalanche photodiodes. Preliminary tests are being performed comparing the performance of these devices with the ones of the PMTs.

88

Comparison of available measurements of the absolute fluorescence yield  

CERN Document Server

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 this work we present a comparison of available results normalized to its value in photons/MeV for the 337 nm band at 800 hPa and 293 K. Possible sources of systematic errors on these measurements are discussed. In particular, the conversion of photons/m to photons/MeV requires an accurate determination of the energy deposited by the electrons in the field of view of the experimental setup. We have calculated the energy deposition for each experiment by means of a detailed Monte Carlo simulation including when possible the geometrical details o...

Rosado, J; Arqueros, F

2010-01-01

89

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)

90

Measurement of environmental radioactivity in Toki district  

International Nuclear Information System (INIS)

When the Institute of Plasma Physics, Nagoya University, expressed the hope to move into Toki district, the environmental problems accompanying the movement were discussed. The effect of the radioactivity leaking from the nuclear facility on human bodies must be far smaller than that of natural radiation, and for the purpose, the amount and fluctuation range of the natural radiation in the district must be known. The initial objectives of this cooperative research were to study on environmental radiation and to make a Geiger counter for the measurement. In 1981, a scintillation counter will be completed, and using a multi-channel pulse height analyzer, the nuclides which are the source of environmental radiation emission will be identified, and the tritium in natural water will be detected. Thus, the evaluation of environmental radiation can be carried out, and the situation before the movement of the research facility can be grasped. In this paper, the natural radioactivity in earth, atmosphere and water and cosmic ray, artificial radioactivity, and environmental radiation exposure dose are reported. Also, the manufacture of a GM counter measuring instrument and the measurements of cosmic ray background, typical earth samples and environmental radioactivity with the GM counter are reported. The related data are attached. (Kako, I.)

91

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)

92

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

OpenAIRE

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. Th...

Jiang, Zhiheng; Palinkas, V.; Francis, O.; Jousset, Philippe; Ma?kinen, J.; Merlet, Se?bastien; Becker, M.; Coulomb, A.; Kessler-schulz, K. U.; Schulz, H. R.; Rothleitner, Ch; Tisserand, L.; Lequin, Delphine

2012-01-01

93

Current measurement system utilizing cryogenic techniques for the absolute measurement of the magnetic flux quantum  

International Nuclear Information System (INIS)

A series of systems composed of cryogenic devices such as a Josephson potentiometer and a cryogenic current comparator has been proposed and developed to precisely measure a current with any value up to 1 A. These systems will be used to measure the injected electrical energy with an uncertainty of the order of 0.01 ppm or less in the absolute measurement of the magnetic flux quantum by superconducting magnetic levitation. Some preliminary experiments are described

94

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.)

95

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

96

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

97

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)

98

Absolute cross section measurement in two nucleons transfer reactions  

International Nuclear Information System (INIS)

Obtaining the absolute values for the nuclear reaction cross sections is a difficult task of tremendous importance for both basic and applied nuclear physics. In the present work we developed a computation tool for calculating the cross sections based on the experimental intensities of the two neutrons transfer direct reactions. The computer program is tested for the (p,t) reactions at 25 MeV beam energy on a 134Ba target. (authors)

99

Absolute measurement of the 125I desintegration rate  

International Nuclear Information System (INIS)

The procedure followed by the Laboratorio de Metrologia Nuclear at the IPEN (Instituto de Pesquisas Energeticas e Nucleares), Sao Paulo - Brazil, for the absolute determination of the 125I desintegration rate by means of the X-(X,?) Coincidence and Sum-Peak methods is described. The results were submitted to the BIPM (Bureau International des Poids et Mesures), France, for an International Comparison of this radionuclide. (author)

100

National network of radioactivity measurement in environment  

International Nuclear Information System (INIS)

This document constitutes the report of management for the year 2006 of the national network of measurement of radioactivity in environment, instituted by the article R.1333-11 of the Public Health code. According to the 5. of the decree of 27. june 2005, the Institute of radiation protection and nuclear safety (I.R.S.N.) has for mission to write every year a report of management of the national network of radioactivity measurement in environment. This report has for principal objectives: to do an evaluation on organisation and functioning of the piloting committee; to realize a synthesis on the different tasks lead by the working groups; as well as on the human and financial resources devoted to this project; to debrief on the development project of the national network information system. This report must allow to the network actors, as to the professional people and the public, to understand the functioning of the national network and the process implemented for the development of centralization, management and public diffusion tools, of the radioactivity data in environment. The year 2006 was marked by the opening of an Internet gate of the national network. (N.C.)

101

Radioactivity measurement with a plastic scintillation vial  

International Nuclear Information System (INIS)

Introduction: Liquid scintillation counting method is commonly used to measure radioactivity especially for beta emitters because of its high sensitivity. However, since the sample should be mixed with scintillation cocktail of organic liquid, there are problems that the sample could not be recovered and radioactive organic liquid waste is produced. The radioactive waste is usually burned with a specially designed incinerator, so that it needs costs and labor. To resolve the problems, I tried to develop a novel method to measure radioactivity using liquid scintillation counter without scintillation cocktail, and investigated the feasibility of the method. Method: A cylindrical plastic scintillator with well was installed in a counting vial, which is named 'ScintiVial' Sample contained in a 1500 ?L microtube was put in the ScintiVial, and was measured with a liquid scintillation counter. Samples including 200-800 Bq of 32P in 25-1300 ?L of solution and 900 Bq of 125I in 100 ?L solution were measured using the ScintiVial. Results and Discussion: The counting efficiency for 25-1300 ?L of 32P was 28-10%, and that for 100 ?L of 125I was 3%. The counting efficiency was decreased with the increase of the sample volume. The pulse height distribution of the ScintiVial was similar to that of usual liquid scintillation of the nuclide in question. The microtube, commonly known as 'Eppendorf tube', for containing the sample is widel', for containing the sample is widely used for experiments of chemistry etc., and also used to contain most of labeled compounds. Using the ScintiVial made them possible that the sample on an experiment may be measured as it is and the sample may be recovered and reused. In addition, the method will not produce any radioactive organic liquid waste. Not producing the active organic liquid will eliminate the load for its incineration, and then CO2 with the incineration will not be generated. Therefore, the method will potentially assist the resolution of the environmental problem caused by CO2. One of the methods without scintillation cocktail is using a solid scintillator (ReadyCap, Beckman). However, the method needs to dry up the sample, so it requires certain time to dry up and is not applicable for volatile compounds. Also the sample could not be recovered and the solid waste would be produced. Another method is the Cherenkov counting. The method is applicable for the nuclides emitting beta rays with energy more than 260 keV, if water is used for the medium of Cherenkov effect. To detect lower energies, Takiue et al. proposed a method using a high-refractive transparent ceramic. The method, however, needs to dry up the sample. In contrast, using the ScintiVial, one does not need to dry up the sample. More than ten times use of the ScintiVial may be less expensive than the whole c.ost of liquid scintillation counting, which includes 10-mL cocktail, counting vial, and the cost for incineration. Conclusion: The ScintiVial method to measure radioactivity using a liquid scintillation counter was developed. The counting efficiency for 32P was 28-10% and that for 125I was 3%. This method is quite simple, is less expensive, and do not produce any radioactive organic liquid waste. Furthermore the sample can be recovered.

102

Gravity measurements with a portable absolute gravimeter A10 in Syowa Station and Langhovde, East Antarctica  

Science.gov (United States)

Absolute gravity values were measured with a portable absolute gravimeter A10 in East Antarctica, for the first time by the Japanese Antarctic Research Expedition. This study aims to investigate regional spatiotemporal variations of ice mass distributions and associated crustal deformations around Syowa Station by means of repeated absolute gravity measurements, and we obtained the first absolute gravity value in Southern Langhovde on the Antarctic Continent. The average absolute gravity value at the newly installed benchmark AGS01 in Langhovde (obtained on 3 February 2012) was 982535584.2 ± 0.7 ?gal (1 [?gal] = 1 × 10-8 [m/s2]), which was in agreement with the gravity values obtained by the past relative gravity measurements within 1 mgal. In addition, the average absolute gravity value obtained at AGSaux in Syowa Station was consistent with both previous absolute gravity values and those obtained by simultaneous measurements using an FG5 gravimeter, owing to adequate data corrections associated with tidal effects and time variations in atomic clock frequencies. In order to detect the gravity changes associated with the ice mass changes and other tectonic phenomena, we plan to conduct absolute gravity measurements at AGS01 again and at other campaign sites around Syowa Station as well in the near future, with careful attention paid to the impacts of severe environmental conditions in Antarctica on gravity data collection.

Kazama, Takahito; Hayakawa, Hideaki; Higashi, Toshihiro; Ohsono, Shingo; Iwanami, Shunsuke; Hanyu, Tomoko; Ohta, Harumi; Doi, Koichiro; Aoyama, Yuichi; Fukuda, Yoichi; Nishijima, Jun; Shibuya, Kazuo

2013-09-01

103

High-frequency method for pulsed photon exposure dose rate absolute measurements  

International Nuclear Information System (INIS)

Modern state of the problem of absolute measurements of the dose rate of pulse fluxes of high intense ionizing radiation is considered. Absolute measurements of bremsstrahlung exposure dose rate of a heavy-current accelerator within the 107-1010 R/s are conducted using the HF-method of plasma diagnostics formed during air irradiation by ionizing radiation. The results of measurements have been compared with the readings of recommended dosimeters, measuring errors have been analyzed. It is shown that the main error of absolute measuring the exposure dose rate by the HF-method does not exceed 40%. Means for determination of the exposure dose rate within 107-1013 R/s range with up to 10-9 time resolution and essentially smaller error of absolute measurements as compared with scintillation methods can be made on the base of the HF-method

104

Measures of radioactivity: a tool for understanding statistical data analysis  

OpenAIRE

A learning path on radioactivity in the last class of high school is presented. An introduction to radioactivity and nuclear phenomenology is followed by measurements of natural radioactivity. Background and weak sources are monitored for days or weeks. The data are analyzed in order to understand the importance of statistical analysis in modern physics.

Montalbano, Vera; Quattrini, Sonia

2012-01-01

105

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

106

The measurement of absolute MDP concentration in the skull  

International Nuclear Information System (INIS)

An original approach to the quantitative assessment of bone turnover is presented. With emission tomography, it has been possible to assess, in absolute, ? Ci/ml units, the amount of tracer - 99m-Tc-MDP taken up by the skull in man. A method has been developed utilising the Cleon-710 Brain Scanner (to be reintroduced into the commercial environment), appropriate ring phantoms for quality control and calibration and bone biopsies for ultimate in vivo/in vitro count correlation. A wax skull phantom to assess the effects of the reconstruction algorithm on linearity, resolution and derived uptake values was developed.The size and shape of the phantom were representative of a section at the mid brain level. The dimensions of the skull sections could be varied and filled with various concentrations of 99m-Tc. Phantom studies indicate a linear response for activities above O.O1?Ci/ml. There was minimal distortion below this value. The effect of resolution is significant for activity distributions with frequency components greater than the Nyquist frequency (for the system). The result would be an incorrect assessment of skull volume and hence uptake. This is known as the partial volume effect for which an appropriate correction has been derived and applied to the data. The technique is dependent upon several assumptions, principally that the calibration of the phantom used is representative of the clinical environment, that an average value for skull thickness can be applie value for skull thickness can be applied, and that the peak reconstructed activity distribution is adequate to described clinical disease states. The effect of each of these will be discussed together with the corroborative data obtained from bone biopsy studies. (Author)

107

Absolute intensity measurement of internal Bremsstrahlung from 57Co  

International Nuclear Information System (INIS)

The Internal Bremsstrahlung (IB) spectrum from 57Co has been re-measured in two separate experiments. In the measurement of IB in coincidence with 122 keV gamma rays of 57Fe, the energy range of IB spectrum could be extended below 300 keV. In the other measurement involving IB in coincidence with K-X-rays of 57Fe, the uncertainty in the end-point-energy value has reduced by almost a factor of two. In both cases, the measured intensity of IB spectra shows a good agreement with the theoretical predictions of Martin and Glauber. (author)

108

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

109

Absolute measurement of beam energy by Compton scattering  

International Nuclear Information System (INIS)

We propose that the energy of a relativistic electron beam can be measured by observing the Compton radiation it scatters from a resonating cavity. The radiation is to be observed at the frequency at which the intensity does not depend upon the phase of the beam relative to the rf. The measurement will give ?E/E to within 10-4 in about 10 seconds for a 1 mA beam. The number of photons can be significantly increased, and the measuring time decreased proportionately, by use of an rf wiggler in place of the cavity

110

Absolute measurement of ?-ray emitter radioelements by spectrometry (1963)  

International Nuclear Information System (INIS)

The proposed apparatus is composed of a lead collimator and a thallium sodium iodide activated scintillation detector. The geometrical solid angle is determined by the collimator, but the real solid angle is larger owing to the ?-ray filtration in the inner sides. The filtration coefficient to apply for obtention of the counting rate corresponding to the geometrical solid angle has been calculated and measured experimentally. ?-rays are scattered in the shielding of the scintillator what as a consequence to increase the counting rate. The scattering coefficient to apply for obtaining the real counting rate has been measured experimentally. The device efficiency for different ?-ray energies has been calculated and measured experimentally. A certain quantity of ?-ray emitter radioelements have been measured. The accuracy is 4 per cent. (author)

111

European Measurement Comparisons of Environmental Radioactivity  

Science.gov (United States)

The scheme of European measurement comparisons to verify radioactivity monitoring in the European Union is briefly explained. After a review of comparisons conducted during the years 1990, the approach of IRMM organising these comparisons since 2003 is presented. IRMM is providing comparison samples with a reference value traceable to the SI units and which is fully documented to all participants and national authorities after completion of the comparison. The sample preparation and determination of traceable reference values at IRMM, the sample treatment and measurement in the participating laboratories, as well as the evaluation of comparison results are described in some detail using the example of an air filter comparison. The results of a comparison to determine metabolised 40K, 90Sr and 137Cs in milk powder are presented as well. The necessary improvements in the estimation of measurement uncertainty by the participating laboratories are discussed. The performance of individual laboratories which have participated in at least four comparison exercises over the years is studied in terms of observable trends.

Wätjen, Uwe

2008-08-01

112

Infrastructure development of radiation measurement system for illicit radioactive materials  

International Nuclear Information System (INIS)

On NORM (Naturally Occurring Radioactive Material) and export/import goods including the small radioactive material, it is also required for public that the level of the radiation safety and reassuring is raised to use the radiation measurement or the identification of radioactive material. Furthermore, it becomes in the age of which the necessity of radioactive material identification of the unidentified packing is strongly obtained in order to previously prevent nuclear-terrorism and dirty bomb. In NUSTEC, Infrastructure development of radiation measurement system for illicit use of radioactive materials is promoted using of the experience in measuring technique and gamma-ray spectrum measuring instrument (semiconductor detector, etc.) regulated at ISO22188 in the case of receiving a request from the government, local fire service and police. In this paper, improvement situation of the radioactive material detection equipment in our center is described. (author)

113

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.)

114

An Absolute Flux Density Measurement of the Supernova Remnant Casseopia A at 32 GHz  

OpenAIRE

We report 32 GHz absolute flux density measurements of the supernova remnant Cas A, with an accuracy of 2.5%. The measurements were made with the 1.5-meter telescope at the Owens Valley Radio Observatory. The antenna gain had been measured by NIST in May 1990 to be $0.505 \\pm 0.007 \\frac{{\\rm mK}}{{\\rm Jy}}$. Our observations of Cas A in May 1998 yield $S_{cas,1998} = 194 \\pm 5 {\\rm Jy}$. We also report absolute flux density measurements of 3C48, 3C147, 3C286, Jupiter, Satur...

Mason, Brian S.; Leitch, Erik M.; Myers, Steven T.; Cartwright, John K.; Readhead, A. C. S.

1999-01-01

115

An Absolute Flux Density Measurement of the Supernova Remnant Cassiopeia A at 32 GHZ  

Science.gov (United States)

We report 32 GHz absolute flux density measurements of the supernova remnant Cas A, with an accuracy of 2.5%. The measurements were made with the 1.5 m telescope at the Owens Valley Radio Observatory. The antenna gain had been measured by NIST in May 1990 to be 0.505+/-0.007 mK Jy-1. Our observations of Cas A in May 1998 yield Scas,1998=194+/-5 Jy. We also report absolute flux density measurements of 3C 48, 3C 147, 3C 286, Jupiter, Saturn, and Mars.

Mason, Brian S.; Leitch, Erik M.; Myers, Steven T.; Cartwright, John K.; Readhead, A. C. S.

1999-12-01

116

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.)

117

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.

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

2015-01-01

118

Measurement of the Absolute Branching Fraction of Ds+??+?? Decay  

International Nuclear Information System (INIS)

Using a sample of tagged Ds+ decays collected near the Ds*±Ds± peak production energy in e+e- collisions with the CLEO-c detector, we study the leptonic decay Ds+??+?? via the decay channel ?+?e+?e??. We measure B(Ds+??+??)=(6.17±0.71±0.34)%, where the first error is statistical and the second systematic. Combining this result with our measurements of Ds+??+?? and Ds+??+?? (via ?+??+??), we determine fDs=(274±10±5) MeV

119

Absolute measurement of the thermal conductivity at low temperatures  

International Nuclear Information System (INIS)

The method consists in launching through a cylindrical sample of cross section S, a longitudinal well-defined thermal flux F and measuring the corresponding steady gradient of temperature G. The thermal conductivity coefficient K is deduced. At the mean experimental temperature: K=F/S.G

120

Absolute gain measurement of microstrip antennas under mismatched conditions  

Science.gov (United States)

The gain of a single microstrip patch and a two-layer parasitic array is measured using the image method under mismatched conditions. This method produces accurate results, even in the case of low-gain microstrip antennas. The advantages of this method over the gain comparison technique are discussed.

Lee, R. Q.; Baddour, M. F.

1988-01-01

121

Methods of measuring radioactivity in the environment  

International Nuclear Information System (INIS)

A variety of sampling methods have been utilized to assess the amount of deposited activity, mainly from 137Cs, from the Chernobyl accident and from nuclear weapons tests. Starting with the Chernobyl accident in 1986 sampling of air and rain was used to determine the composition and amount of radioactive debris from this accident. The resulting deposition and its removal from urban areas was then studied through measurements on sewage sludge and water. The main part of the thesis considers methods of determining the amount of radiocesium in the ground through soil sampling. In connection with soil sampling a method of optimizing the sampling procedure has been developed and tested in the areas of Sweden with high amounts of 137Cs from the Chernobyl accident. This method was then used in a survey of the activity in soil in Scania (south Sweden) with fallout activity from nuclear weapons and Chernobyl. By comparing the results from this survey with deposition calculated from precipitation measurements it was found possible to predict the deposition pattern over Scania for both nuclear weapons and Chernobyl fallout. In addition, the vertical distribution of 137Cs has been modelled and the temporal variation of the depth distribution has been described. 65 refs

122

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)

123

4? proportional counter for absolute measurement of ?-emitters  

International Nuclear Information System (INIS)

The 4? counter is commonly used to measure the activity of ? sources, the one we describe does not advance a new conception but the issue of several years of investigations. The apparatus presents good performances about the qualities commonly required in that kind of counter: detection efficiency, plateau and dead time. Moreover technical characteristics give a great flexibility in use, particularly a possibility of adaptation in a ?,? coincidence unit. (authors)

124

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)

125

Absolute measurements of the excitation amplitude at ferromagnetic resonance  

International Nuclear Information System (INIS)

Using X-ray magnetic circular dichroism (XMCD) we directly measure the transversal components of the precessing magnetization in a thin film under cw microwave excitation (phase locked to the X-ray flashes). The real and imaginary parts of the rf-magnetic susceptibility are obtained by adjusting the phase between exciting microwave signal and the X-ray flashes to 0 and 90 , respectively. Measurements at different angles between the sample plane and the X-ray beam allow to determine the in and out-of-plane rf magnetization components and thereby the ellipticity of the precession. Since the signal is calibrated by XMCD hysteresis loops the excursion angle can be evaluated. At large microwave fields the susceptibility becomes nonlinear due to the decrease of the effective magnetization and the excitation of parametric spin waves (Suhl instability). We measure the precession angle and the ellipticity as function of rf power up to the nonlinear regime. XMCD also allows for an element specific and therefore layer sensitive investigation of the magnetization dynamics. Optic and acoustic modes are observed in an interlayer exchange coupled sample Co90Fe10/Ru/Ni80Fe20. From the phase difference between the precessing magnetizations of both layers the coupling energy is determined.

126

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

127

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

128

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

129

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)

130

Development of a fast impedance probe for absolute electron density measurements in the ionosphere  

International Nuclear Information System (INIS)

The design of a digitally controlled impedance probe for the fast absolute measurement of the ionospheric plasma density aboard a sounding rocket is described. Instrument performance is tested in a large plasma chamber. The first results from two flights within the DEOS-campaign are reported, and discussed with respect to spatial resolution and wake effects. The resulting density profiles have the same shape as ground-based ionosonde measurements. The in situ impedance probe measurements yield absolute electron densities that are lower by a factor of 1.5-2. (author)

131

Method for the absolute measurement of photon energies  

Energy Technology Data Exchange (ETDEWEB)

We present a Monte Carlo study of the Compton scattering of high energy photons on atomic electrons of a {sup 27} Al target. The calculation was done in order to estimate the potentiality of using this reaction for high precision measurements of photon energies. A computer code was developed, based on relativistic reaction kinematics in impulse approximation, accounting for the final atom kinetic energy and the internal motion of the atomic electrons. The code includes the rescattering of the emitted electron in the target material, and allows to study the influence of several geometrical parameters of the system on the accuracy with which the initial photon energy is determined. The results of the simulations show that, for high intensity photon beams, the energy of the photons can be determined with a relative accuracy of 10{sup -3}. (author)

Likhachev, V.P.; Arruda Neto, J.D.T.; Deppman, A.; Cruz, M.T.F.; Carvalho, W.R.; Gavrikov, V.B.; Martins, M.N.; Mesa, J. [Universidade de Sao Paulo, SP (Brazil). Inst. de Fisica. Lab. do Acelerador Linear; Margarian, A. [Yerevan Institute of Nuclear Physics (Armenia)

2001-07-01

132

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

133

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

134

Absolute measurement of the DT primary neutron yield on the National Ignition Facility  

Directory of Open Access Journals (Sweden)

Full Text Available The measurement of the absolute neutron yield produced in inertial confinement fusion target experiments conducted on the National Ignition Facility (NIF is essential in benchmarking progress towards the goal of achieving ignition on this facility. This paper describes three independent diagnostic techniques that have been developed to make accurate and precise DT neutron yield measurements on the NIF.

Leeper R.J.

2013-11-01

135

Absolute measurement of the DT primary neutron yield on the National Ignition Facility  

International Nuclear Information System (INIS)

The measurement of the absolute neutron yield produced in inertial confinement fusion target experiments conducted on the National Ignition Facility (NIF) is essential in benchmarking progress towards the goal of achieving ignition on this facility. This paper describes three independent diagnostic techniques that have been developed to make accurate and precise DT neutron yield measurements on the NIF. (authors)

136

Total absolute electron-metastable neon collision cross section measurements via a magneto-optical trap  

International Nuclear Information System (INIS)

Full text: In this paper we will present an experimental technique that utilises a magneto-optical trap for atoms in the 2P3/23s[3/2]2 metastable state of neon for the measurement of total absolute collision cross sections. The technique allows the determination of these cross sections without the knowledge of target density. Progress on new absolute total collision cross sections measurements using these techniques with a new experimental apparatus that produces a bright beam of laser-cooled metastable neon will be reported

137

Comparative Test of Two Methods of Quantum Efficiency Absolute Measurement Based on Squeezed Vacuum Direct Detection  

CERN Document Server

We realize and test in experiment a method recently proposed for measuring absolute quantum efficiency of analog photodetectors. Similarly to the traditional (Klyshko) method of absolute calibration, the new one is based on the direct detection of two-mode squeezed vacuum at the output of a traveling wave OPA. However, in the new method one measures the difference-photocurrent variance rather than the correlation function of photocurrents (number of coincidences), which makes the technique applicable for high-gain OPA. In this work we test the new method versus the traditional one for the case of photon-counting detectors where both techniques are valid.

Agafonov, I N; Iskhakov, T Sh; Penin, A N; Rytikov, G O; Shumilkina, O A

2010-01-01

138

Physical Measure and Absolute Continuity for One-Dimensional Center Direction  

CERN Document Server

For a class of partially hyperbolic $C^k$, $k>1$ diffeomorphisms with circle center leaves we prove existence and finiteness of physical (or Sinai-Ruelle-Bowen) measures, whose basins cover a full Lebesgue measure subset of the ambient manifold. Our conditions contain an open and dense subset of all $C^k$ partially hyperbolic skew-products on compact circle bundles. Our arguments blend ideas from the theory of Gibbs states for diffeomorphisms with mostly contracting center direction together with recent progress in the theory of cocycles over hyperbolic systems that call into play geometric properties of invariant foliations such as absolute continuity. Recent results show that absolute continuity of the center foliation is often a rigid property among volume preserving systems. We prove that this is not at all the case in the dissipative setting, where absolute continuity can even be robust.

Viana, Marcelo

2010-01-01

139

Gravity studies at Etna volcano: a comparison between relative and absolute gravity measurements  

Science.gov (United States)

The INGV has been operating at Mt Etna a discrete gravity network since 1986 and three continuous gravity stations since 1998. The combined use of discrete and continuous gravity measurements has provided, through the detection of phenomena with a wide range of evolution rates (periods ranging from minutes to years), both substantial improvements in the knowledge of the dynamics of the shallow plumbing system at Etna and the identification of any gravity transient before and during the last volcanic eruptions. Recently, with the aim of compare relative microgravity measurements routinely acquired on Etna volcano using spring gravimeters with absolute gravity observations, we performed two surveys in June 2007 and July 2008 by using the new IMGC-02 transportable absolute gravimeter. The IMGC-02 transportable instrument, developed by INRiM - Torino, adopts the absolute ballistic method, which was recognized at international level (Comité International des Poids et Mesures - CIPM) as primary method of measurement of the acceleration due to gravity. Taking into account the logistic situation of Etna, four absolute gravity stations were settled in 2007, while a fifth station was installed in 2008. Four of them were located very close to the active craters at: (i) the Serra la Nave Astrophysical Observatory (1740 m a.s.l.); (ii) the Montagnola (2500 m a.s.l.); (iii) the Pizzi Deneri Volcanological Observatory (2810 m a.s.l.); and the newest (iv) the Caserma Donnavita (1250 m a.s.l.). One absolute station was installed out of the volcanic area, inside the gravity laboratory of INGV - Catania, to be adopted as reference. We present the results obtained by comparing relative and absolute gravity measurements and their implications on the latest Etna eruption started on 13th May 2008.

Greco, F.; D'Agostino, G.; Del Negro, C.; Germak, A.; Sicali, A.; Vitiello, F.

2008-12-01

140

Absolute calibration of a wideband antenna and spectrometer for sky noise spectral index measurements  

CERN Document Server

A new method of absolute calibration of sky noise temperature using a three-position switched spectrometer, measurements of antenna and low noise amplifier impedance with a vector network analyzer, and ancillary measurements of the amplifier noise waves is described. The details of the method and its application to accurate wideband measurements of the spectral index of the sky noise are described and compared with other methods.

Rogers, Alan E E

2012-01-01

141

Absolute metastable atom-atom collision cross section measurements using a magneto-optical trap.  

Science.gov (United States)

We present a new technique to measure absolute total collision cross sections from metastable neon atoms. The technique is based on the observation of the decay rate of trapped atoms as they collide with room temperature atoms. We present the first measurement of this kind using trapped neon atoms in the (3)P(2) metastable state colliding with thermal ground state argon. The measured cross section has a value of 556+/-26 A(2). PMID:17672750

Matherson, K J; Glover, R D; Laban, D E; Sang, R T

2007-07-01

142

Absolute metastable atom-atom collision cross section measurements using a magneto-optical trap  

International Nuclear Information System (INIS)

We present a new technique to measure absolute total collision cross sections from metastable neon atoms. The technique is based on the observation of the decay rate of trapped atoms as they collide with room temperature atoms. We present the first measurement of this kind using trapped neon atoms in the 3P2 metastable state colliding with thermal ground state argon. The measured cross section has a value of 556±26 A ring 2

143

In situ measurement of leaf chlorophyll concentration: analysis of the optical/absolute relationship.  

Science.gov (United States)

In situ optical meters are widely used to estimate leaf chlorophyll concentration, but non-uniform chlorophyll distribution causes optical measurements to vary widely among species for the same chlorophyll concentration. Over 30 studies have sought to quantify the in situ/in vitro (optical/absolute) relationship, but neither chlorophyll extraction nor measurement techniques for in vitro analysis have been consistent among studies. Here we: (1) review standard procedures for measurement of chlorophyll; (2) estimate the error associated with non-standard procedures; and (3) implement the most accurate methods to provide equations for conversion of optical to absolute chlorophyll for 22 species grown in multiple environments. Tests of five Minolta (model SPAD-502) and 25 Opti-Sciences (model CCM-200) meters, manufactured from 1992 to 2013, indicate that differences among replicate models are less than 5%. We thus developed equations for converting between units from these meter types. There was no significant effect of environment on the optical/absolute chlorophyll relationship. We derive the theoretical relationship between optical transmission ratios and absolute chlorophyll concentration and show how non-uniform distribution among species causes a variable, non-linear response. These results link in situ optical measurements with in vitro chlorophyll concentration and provide insight to strategies for radiation capture among diverse species. PMID:24635697

Parry, Christopher; Blonquist, J Mark; Bugbee, Bruce

2014-11-01

144

Monte Carlo calculation for an absolute measurement of 99mTc  

International Nuclear Information System (INIS)

Absolute measurement of 99mTc was carried out and extrapolation line was calculated. The extrapolated line calculated by Monte Carlo calculation was consistent with that obtained by experimental data of 99mTc. We will apply the Monte Carlo calculation to the nuclide whose decay scheme is complicated or extrapolation curve is not linear. (author)

145

Calculator for Standard Deviation and Optimum Conditions in Radioactive Measurements  

International Nuclear Information System (INIS)

A calculating device is described, suited for fast orientation in the conditions of radioactive measurements. Its usage minimizes the time needed for calculating the statistical accuracy and minimum detectable activity. The typical problems which could be solved by using it are as follows: (a) Calculation of the statistical accuracy (percentage natural standard deviation) for any radioactive measurement. (b) Determination of the minimum detectable activity (in count rate) for a chosen probability limit of the net count rate of the order of 90%, 95% 99%. (c) Determination of the optimum statistical conditions of the measurement. (d) Choice of the most suitable detector. The disadvantages of the existing automatic detectors used for measurement of radioactive samples are discussed and the ways to avoid them are shown. A counting device designed to measure radioactive samples with programmed statistical accuracy is described. (author)

146

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

147

Absolute phase retrieval for defocused fringe projection three-dimensional measurement  

Science.gov (United States)

Defocused fringe projection three-dimensional technique based on pulse-width modulation (PWM) can generate high-quality sinusoidal fringe patterns. It only uses slightly defocused binary structured patterns which can eliminate the gamma problem (i.e. nonlinear response), and the phase error can be significantly reduced. However, when the projector is defocused, it is difficult to retrieve the absolute phase from the wrapped phase. A recently proposed phase coding method is efficient for absolute phase retrieval, but the gamma problem leads this method not so reliable. In this paper, we use the PWM technique to generate fringe patterns for the phase coding method. The gamma problem of the projector can be eliminated, and correct absolute phase can be retrieved. The proposed method only uses two grayscale values (0's and 255's), which can be used for real-time 3D shape measurement. Both simulation and experiment demonstrate the performance of the proposed method.

Zheng, Dongliang; Da, Feipeng

2014-02-01

148

In-house absolute calibration of gamma-emitting radioactive voluminous samples. Detector setups using natural radionuclides  

International Nuclear Information System (INIS)

A method for the absolute calibrations of ?-rays spectrometers for voluminous samples using natural radionuclides is suggested. The method is based on relative calibration with a solution of 232Th salts and absolute calibration with K2CO3 or KCl. (author)

149

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

150

The French National Network for the Measurement of Environmental Radioactivity  

International Nuclear Information System (INIS)

After Chernobyl accident in 1986, the government began to implement mechanisms to ensure the quality of measurements of environmental radioactivity and to assure the transparency of information on environmental radioactivity monitoring results. Within this context, the French National Network for the Measurement of Environmental Radioactivity (RNM), is created in 2002 under the Public Health Code. This network is developed under the auspices of ASN in collaboration with IRSN and in partnership with government departments, major nuclear licensees, health agencies and environmental protection associations. In order to centralize information on environmental radioactivity and to provide access to measurement results, a single database that includes an the results of measurements of radioactivity in the environment on the national territory is build and a new web-site www.mesure-radioactivite.fr is launched. It provides quick and easy access to this database. The quality of measurements is performed by a laboratory system through an ASN decision. Novel initiative in Europe, the French National Network for the Measurement of Environmental Radioactivity web-site gives the user keys to understand the measurement results on the radiological state of the environment. The site will be improved over the time taking into account the feedback of the users. (author)

151

A novel method for the absolute fluorescence yield measurement by AIRFLY  

Energy Technology Data Exchange (ETDEWEB)

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 Cherenkov 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. [University of Chicago, Enrico Fermi Institute, 5640 S Ellis Ave., Chicago, IL 60637 (United States); Bohacova, M. [Institute of Physics of the Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-18221 Praha 8 (Czech Republic)], E-mail: bohacova@fzu.cz; Buonomo, B. [Laboratori Nazionali di Frascati dell' INFN, INFN, Sezione di Frascati, Via Enrico Fermi 40, Frascati, Rome 00044 (Italy); Busca, N.; Cazon, L. [University of Chicago, Enrico Fermi Institute, 5640 S Ellis Ave., Chicago, IL 60637 (United States); Chemerisov, S.D.; Conde, M.E.; Crowell, R.A. [Argonne National Laboratory, Argonne, IL 60439 (United States); Di Carlo, P. [Dipartimento di Fisica dell' Universita de l' Aquila and INFN, Via Vetoio, I-67010 Coppito, Aquila (Italy); Di Giulio, C. [Dipartimento di Fisica dell' Universita di Roma Tor Vergata and Sezione INFN, Via della Ricerca Scientifica, I-00133 Rma (Italy); Doubrava, M. [Czech Technical University, Technicka 4, 16607 Praha 6 (Czech Republic); Esposito, A. [Laboratori Nazionali di Frascati dell' INFN, INFN, Sezione di Frascati, Via Enrico Fermi 40, Frascati, Rome 00044 (Italy); Facal, P. [Departmento de Fi' sica de Parti' culas, Campus Sur, Universidad, E-15782, Santiago de Compostela (Spain); Franchini, F.J. [Argonne National Laboratory, Argonne, IL 60439 (United States); Hoerandel, J.R. [Universitaet Karlsruhe (Thailand), Institut fuer Experimentelle Kernphysik (IEKP), Postfach 6980, D-76128 Karlsruhe (Germany); Hrabovsky, M. [Institute of Physics of the Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-18221 Praha 8 (Czech Republic); Iarlori, M. [Dipartimento di Fisica dell' Universita de l' Aquila and INFN, Via Vetoio, I-67010 Coppito, Aquila (Italy); Kasprzyk, T.E. [Argonne National Laboratory, Argonne, IL 60439 (United States); Keilhauer, B. [Universitaet Karlsruhe (Thailand), Institut fuer Experimentelle Kernphysik (IEKP), Postfach 6980, D-76128 Karlsruhe (Germany)] (and others)

2008-11-21

152

Absolute continuity of projected SRB measures of coupled Arnold cat map lattices  

CERN Document Server

We study a d-dimensional coupled map lattice consisting of hyperbolic toral automorphisms (Arnold cat maps) that are weakly coupled by an analytic coupling map. We construct the Sinai-Ruelle-Bowen measure for this system and study its marginals on the tori. We prove they are absolutely continuous with respect to the Lebesgue measure if and only if the coupling satisfies a nondegeneracy condition.

Bonetto, F; Lebowitz, J L

2003-01-01

153

Measurements of the absolute intensities for the ?-rays from 156Eu decay  

International Nuclear Information System (INIS)

156Eu activity is obtained from the 154Sm sample irradiated by reactor neutrons and through chemical separation by ion-exchange technique. Activity is measured using 4??-? coincidence apparatus and photon counting is performed applying HPGe and small-area planar Ge detectors. From these measurements the absolute intensities for the ?-rays emitted from decay of 156Eu are determined. The uncertainties of experimental results are less than 2%

154

ArtDeco: A beam deconvolution code for absolute CMB measurements  

OpenAIRE

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...

Keiha?nen, Elina; Reinecke, Martin

2012-01-01

155

Measurement of the thermal neutron capture cross section and the resonance integral of radioactive Hf182  

Science.gov (United States)

The neutron capture cross sections of the radioactive isotope Hf182 (t1/2=8.9×106 yr) in the thermal and epithermal energy regions have been measured by activation at the TRIGA Mark-II reactor of the Atomic Institute of the Austrian Universities in Vienna, Austria, and subsequent ?-ray spectroscopy of Hf183. High values for the thermal (kT=25 meV) cross section ?0=133±10 b and for the resonance integral I0=5850±660 b were found. Additionally, the absolute intensities of the main ?-ray transitions in the decay of Hf182 have been considerably improved.

Vockenhuber, C.; Bichler, M.; Wallner, A.; Kutschera, W.; Dillmann, I.; Käppeler, F.

2008-04-01

156

Measurement of the thermal neutron capture cross section and the resonance integral of radioactive 182Hf  

International Nuclear Information System (INIS)

The neutron capture cross sections of the radioactive isotope 182Hf (t1/2=8.9x106 yr) in the thermal and epithermal energy regions have been measured by activation at the TRIGA Mark-II reactor of the Atomic Institute of the Austrian Universities in Vienna, Austria, and subsequent ?-ray spectroscopy of 183Hf. High values for the thermal (kT=25 meV) cross section ?0=133±10 b and for the resonance integral I0=5850±660 b were found. Additionally, the absolute intensities of the main ?-ray transitions in the decay of 182Hf have been considerably improved

157

Absolute gravity measurements at three sites characterized by different environmental conditions using two portable ballistic gravimeters  

Science.gov (United States)

The performances of two absolute gravimeters at three different sites in Italy between 2009 and 2011 is presented. The measurements of the gravity acceleration g were performed using the absolute gravimeters Micro-g LaCoste FG5#238 and the INRiM prototype IMGC-02, which represent the state of the art in ballistic gravimeter technology (relative uncertainty of a few parts in 109). For the comparison, the measured g values were reported at the same height by means of the vertical gravity gradient estimated at each site with relative gravimeters. The consistency and reliability of the gravity observations, as well as the performance and efficiency of the instruments, were assessed by measurements made in sites characterized by different logistics and environmental conditions. Furthermore, the various factors affecting the measurements and their uncertainty were thoroughly investigated. The measurements showed good agreement, with the minimum and maximum differences being 4.0 and 8.3 ?Gal. The normalized errors are very much lower than 1, ranging between 0.06 and 0.45, confirming the compatibility between the results. This excellent agreement can be attributed to several factors, including the good working order of gravimeters and the correct setup and use of the instruments in different conditions. These results can contribute to the standardization of absolute gravity surveys largely for applications in geophysics, volcanology and other branches of geosciences, allowing achieving a good trade-off between uncertainty and efficiency of gravity measurements.

Greco, Filippo; Biolcati, Emanuele; Pistorio, Antonio; D'Agostino, Giancarlo; Germak, Alessandro; Origlia, Claudio; Del Negro, Ciro

2015-03-01

158

Laser induced deflection (LID) method for absolute absorption measurements of optical materials and thin films  

Science.gov (United States)

We use optimized concepts to measure directly low absorption in optical materials and thin films at various laser wavelengths by the laser induced deflection (LID) technique. An independent absolute calibration, using electrical heaters, is applied to obtain absolute absorption data without the actual knowledge of the photo-thermal material properties. Verification of the absolute calibration is obtained by measuring different silicon samples at 633 nm where all laser light, apart from the measured reflection/scattering, is absorbed. Various experimental results for bulk materials and thin films are presented including measurements of fused silica and CaF2 at 193 nm, nonlinear crystals (LBO) for frequency conversion and AR coated fused silica for high power material processing at 1030 nm and Yb-doped silica raw materials for high power fiber lasers at 1550 nm. In particular for LBO the need of an independent calibration is demonstrated since thermal lens generation is dominated by stress-induced refractive index change which is in contrast to most of the common optical materials. The measured results are proven by numerical simulations and their influence on the measurement strategy and the obtained accuracy are shown.

Mühlig, Christian; Bublitz, Simon; Paa, Wolfgang

2011-05-01

159

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

160

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

161

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

Energy Technology Data Exchange (ETDEWEB)

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.

Mackinnon, A; Casey, D; Frenje, J A; Johnson, M G; Seguin, F H; Li, C K; Petrasso, R D; Glebov, V Y; Katz, J; Knauer, J; Meyerhofer, D; Sangster, T; Bionta, R; Bleuel, D; Hachett, S P; Hartouni, E; Lepape, S; Mckernan, M; Moran, M; Yeamans, C

2012-05-03

162

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.

163

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

164

System for absolute measurement of electrolytic conductivity in aqueous solutions based on van der Pauw's theory  

Science.gov (United States)

Based on an innovative application of van der Pauw's theory, a system was developed for the absolute measurement of electrolytic conductivity in aqueous solutions. An electrolytic conductivity meter was designed that uses a four-electrode system with an axial-radial two-dimensional adjustment structure coupled to an ac voltage excitation source and signal collecting circuit. The measurement accuracy, resolution and repeatability of the measurement system were examined through a series of experiments. Moreover, the measurement system and a high-precision electrolytic conductivity meter were compared using some actual water samples.

Zhang, Bing; Lin, Zhen; Zhang, Xiao; Yu, Xiang; Wei, Jiali; Wang, Xiaoping

2014-05-01

165

Radioactivity measuring system of labelled biopolymers  

International Nuclear Information System (INIS)

System for determining the radioactivity of labelled biopolymers, comprising a bank of containers filled with aqueous solutions of biological samples containing biopolymers. This system features an electric drive to move the bank of containers step by step; a device for the acid precipitation of the biopolymers which sends determined amounts of co-precipitant and diatom suspension in an acid solution to the containers containing a biological sample; a system for taking precipitated samples from the containers; a system for filtering the precipitated biopolymers carrying out successive filterings; placing the deposit into suspension; dissolving the biopolymers and sending the labelled mixture labelled by the scintillation labeller to the detection chamber

166

Measurement of absolute neutron flux in LWSCR based on the nuclear track method  

International Nuclear Information System (INIS)

Highlights: ? Up to now the spectral parameters of thermal neutrons are measured with activation foils that are not always reliable in low flux systems. ? We applied a solid state nuclear track detector to measure the absolute neutron flux in the light water sub-critical reactor (LWSCR). ? Experiments concerning fission track detecting were performed and were investigated using the Monte Carlo code MCNP. ? The neutron fluxes obtained in experiment are in fairly good agreement with the results obtained by MCNP. - Abstract: In the present paper, a solid state nuclear track detector is applied to measure the absolute neutron flux in the light water sub-critical reactor (LWSCR) in Nuclear Science and Technology Research Institute (NSTRI). Up to now, the spectral parameters of thermal neutrons have been measured with activation foils that are not always reliable in low flux systems. The method investigated here is the irradiation method. Experiments concerning fission track detecting were performed. The experiment including neutron flux calculation method has also been investigated using the Monte Carlo code MCNP. The analysis shows that the values of neutron flux obtained by experiment are in fairly good agreement with the results obtained by MCNP. Thus, this method may be able to predict the absolute value of neutron flux at LWSCR and other similar reactors.

167

Measurement network for atmospheric radioactivity managed by ASPA  

International Nuclear Information System (INIS)

It was after the Chernobyl accident that a management committee of the radioactivity in Alsace has been put in place (composed of representatives from state, local governments, scientific organizations and associations). This committee entrusted ASPA to manage a measurement network for radioactivity in Alsace composed of 5 stations. ASPA provides automatic communication of results hourly on its web-site www.atmo-alsace.net/site/Radioactivite-13.html to enable its members and the public to have at any time information of artificial radioactivity in air in Alsace. In case of validated alarm, ASPA performs further analysis, meets the surveillance group and complete information through special announcements. (author)

168

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

169

Absolute measurement of {beta} activities and application to the determination of neutronic densities; Mesure absolue d'activites {beta} et application a la determination des densites neutronique  

Energy Technology Data Exchange (ETDEWEB)

M. Berthelot, to my entrance to the ''Commissariat a l 'Energie Atomique'', proposed me to study the absolute measurement of neutron densities. Very quickly the problem of the absolute activity of {beta} sources became the central object of this work. In a first part, we will develop the methods of absolute determination for {beta} activities. The use of a 4{pi} counter permits to get the absolute activity of all beta radioactive source, susceptible to be put as thin leaf and of period superior than some minutes. The method is independent of the spectra of the measured radioelement. we will describe in the second part some applications which use neutron densities measurement, neutron sources intensities and ratio of cross sections of capture of thermal neutrons. (M.B.) [French] M. Berthelot, a mon entree au ''Commissariat a l 'Energie Atomique'', m'a propose d'etudier la mesure absolue des densites neutroniques. Tres rapidement le probleme de l'activite absolue des sources beta est devenu l'objet central de ce travail. Dans une premiere partie, on abordera les methodes de determination absolue des activites beta. L'utilisation d'un compteur 4{pi} permet d 'obtenir l'activite absolue de toute source radioactive beta, susceptible d'etre mise sous forme de feuille mince et de periode superieure a quelques minutes. La methode est independante du spectre du radioelement mesure. On decrira dans la seconde partie quelques applications a des mesures de densites neutroniques, d'intensites de sources de neutrons et de rapport de sections efficaces de capture de neutrons thermiques. (M.B.)

Cohen, R. [Commissariat a l' Energie Atomique, Lab. du Fort de Chatillon, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1951-01-15

170

Natural radioactivity measurements in soil samples of central Kutahya (Turkey).  

Science.gov (United States)

Measurement of the natural radioactivity of surface soils at 20 locations in central Kutahya has been made using gamma ray spectroscopy. Natural gamma ray radioactivity of the terrestrial nuclides in soil samples and the absorbed gamma ray dose rates of these radionuclides in the air have been calculated throughout different areas of central Kutahya. The average annual effective dose equivalent for a person living in central Kutahya was found to be approximately 57 microSv. PMID:18801755

Sahin, Latife; Cavas, Mustafa

2008-01-01

171

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.)

172

Absolute electron-impact-ionization cross-section measurements of the halogen atoms  

International Nuclear Information System (INIS)

Electron-impact-ionization cross sections have been measured for the halogen atoms F, Cl, Br, and I from threshold to 200 eV. The absolute accuracy is +- 14%, except for F which is +- 20%. The halogen cross sections have shapes similar to those of the neighboring rare gases but are greater in magnitude. Simple semiclassical formulas of electron-impact ionization are able to accurately predict the experimentally determined halogen to rare gas cross-section ratios

173

Measurement of the absolute branching ratio of the K+??+?0(?) decay with the KLOE detector  

International Nuclear Information System (INIS)

We have measured the absolute branching ratio of the K+??+?0(?) decay, using ?20 million tagged K+ mesons collected with the KLOE detector at DA?NE, the Frascati ?-factory. Signal counts are obtained from the fit of the distribution of the momentum of the charged decay particle in the kaon rest frame. The result, inclusive of final-state radiation, is BR(K+??+?0(?))=0.2065±0.0005stat±0.0008syst

174

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

International Nuclear Information System (INIS)

A solution of 152Eu was absolutely standardized by the 4?? (PPC)-? (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 4?? ionization chamber to be (4963.6±15.3) days, and compared with others published values

175

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)

176

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

177

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

178

Absolute measurement of the responses of small lithium glass scintillators to gamma radiation  

International Nuclear Information System (INIS)

The absolute scintillation efficiency and intrinsic resolution of lithium glass scintillators for electron excitation have been determined over a range of electron energies, lithium concentrations and lithium enrichments. Measurements of these response characteristics form part of a study on the possible use of such glasses for the determination of tritium breeding in fusion reactor blanket experiments. The measurements were undertaken to establish a basis for extracting the information relating to tritium production reactions from the background signals induced within the glass scintillators by the neutron/gamma fields of a fusion reactor blanket. Criteria for the selection of glasses most suitable for tritium breeding measurements are discussed in tems of their observed responses

179

Towards absolute activity measurements by ionisation chambers using the PENELOPE Monte-Carlo code  

International Nuclear Information System (INIS)

The Monte-Carlo code PENELOPE for Ionisation Chamber Simulation Method has been applied for the calculation of ionisation-chamber (IC) calibration factors. Measuring only a few radionuclides well selected within the relevant energy range, and determining an adjustable parameter, commonly used radionuclides can be measured without any specific calibration. The simulation revealed a discontinuity in the IC response as a function of photon energy and its dependence on the chemical composition of the radioactive solution

180

Status of underground radioactivity measurements in Hades  

International Nuclear Information System (INIS)

This paper describes the aim of the IRMM activities in the HADES laboratory, the equipment and the measurement program and gives examples of radiopurity measurements carried out in order to develop better low-level measurements.

181

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.)

182

Digital positron lifetime spectrometer for measurements of radioactive materials  

International Nuclear Information System (INIS)

A digital positron lifetime spectrometer for the measurements of 2 GBq level radioactive materials has been constructed and successfully tested. The equipment consists of a state-of-the-art digital oscilloscope and three movable scintillation detectors operating in triple-coincidence mode. The time resolution of 188 ps full-width at half-maximum (FWHM) is achieved for the positron lifetime measurements of radioactive specimens. Also by comparison of measurements of well-known material with and without high 60Co background radiation the ability to measure radioactive specimens is proved. In this paper the performance, construction, installation, optimization and calibration of the setup is reported. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

183

Radiation Protection Research: 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 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'

184

An apparatus for measuring the radioactivity of a sample  

International Nuclear Information System (INIS)

The invention relates to an apparatus for measuring the radioactivity of a sample, containing at least one radioactive source. The apparatus is mainly constituted by an air ionization chamber divided into two articulated parts. The sample, the activity of which is to be measured, is introduced by opening the chamber. The apparatus comprises means for measuring the ionizing current. This is applicable to the control of the activity of sup(99m)Tc contained in a hypodermic syringe prior to the medical use thereof

185

Measurement of the absolute energy scale of MINOS and background measurements in NEMO-3  

International Nuclear Information System (INIS)

MINOS (Main Injector Neutrino Oscillation Search) is an experiment currently running in the US. A beam of neutrinos is created at Fermilab, Chicago, measured in the 1 kiloton 'Near Detector' and then travels 730 km to the 5 kiloton 'Far Detector' in the Soudan Mine, Minnesota. In the intervening time, it is hoped that some of these neutrinos will change from one flavor to another. If this is observed, it is strong evidence for neutrino oscillations, the parameters of which can be measured to 10%. The MINOS experiment is a large project with a huge number of technical issues. Many aspects of the experiment were tested several years before the main experiment itself began to run, by employing a scaled down version of the detectors, known as the Calibration Detector (CalDet). This was placed in a test-beam at CERN and extensively studied, the data from which is analyzed in this thesis. In this thesis, photomultiplier tube crosstalk is discussed, a phenomenon which generates false signals in the MINOS detectors. It is studied and an algorithm presented to enable its removal. Particle identification via various methods at CalDet is also described. Various pieces of hardware are available to assist with this, and a comparison is made to software techniques which are used at the larger MINOS detectors. A study of the CalDet beamline simulation is carried out and the discrepancies with data highlighted and explained. Finally, muon energy loss in CalDet is investigated. A comprgy loss in CalDet is investigated. A comparison is made between published data and the observed data. NEMO-3 is an experiment that has been running for soe tie in the Frejus tunnel between France and italy. It is a 0??? experiment, hoping to show that the neutrino is a Majorana particle and set limits on its mass. This experiment, like every, has backgrounds. The dangerous background signals that arise from the radioactive decay of Uranium and Thorium are discussed in this thesis, specifically the measurement of the quantity of 208Tl and 214Bi in the source foils of the detector. This is achieved by using Monte Carlo simulations of the contaminants behavior in the detector, developing cuts on these events and applying them to the dataset.

186

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

187

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

188

Dosimetric system for measurement of radioactive contaminations  

International Nuclear Information System (INIS)

A dosimetric system for personnel dosimetry and monitoring measuring a contamination without time delay and dead time is described. The system ensures many-point measurement and minimalization of background radiation influence. 1 fig. (A.S.)

189

Absolute heterodyne frequency measurement of the (88)Sr(+) 455-THz S-D single ion transition.  

Science.gov (United States)

A system is described for the absolute frequency measurement of a laser source at 445 THz probing a narrow resonance of a trapped single ion of strontium. The 474-THz frequency from a laser referenced to an iodinestabilized helium-neon laser and a known 29-THz frequency from a saturation-stabilized carbon dioxide laser are mixed in an AgGaS(2) nonlinear crystal to synthesize the 445-THz radiation. A preliminary measurement of the (88)Sr(+) 5s(2)S(1/2)-4d(2)D(5/2) center frequency yielded a frequency of 444779044.14 +/- 0.39 MHz (1sigma). PMID:19876171

Madej, A A; Siemsen, K J

1996-06-01

190

Absolute cross-section measurements for electron-impact ionization of Cl+  

International Nuclear Information System (INIS)

Absolute cross sections for electron-impact ionization of Cl+ have been measured from threshold to 200 eV with the use of the crossed-beams technique. The cross section shows a peak value of 12.8x10-17 cm2 at about 70 eV. Results are compared to the semiempirical prediction formula of Lotz, with scaled cross sections for ions in the same isoelectronic sequence, and with other recent measurements. Expansion coefficients and formulas for generating ionization rate coefficients in the electron temperature range 104?T?107 K are presented

191

Measurements of 7Be radioactivity concentrations in high altitude air  

International Nuclear Information System (INIS)

Preliminary measurements of the 7Be radioactivity concentrations in high altitude air were made between April 1984 and March 1985 in order to check the possibility of use for the analysis of the measured gross beta concentrations. Airborne dusts were collected with a filter type air sampler attached to the F-4EJ aircraft. The measurement of the 7Be radioactivity in the filters was made by gamma-ray spectrometry with a Ge(Li) detector. The results ranging from 0.03 to 5 pCi/m3 are in approximate agreement with the calculated values using the equation derived by B. Peters. Comparing the results of 7Be with the gross beta activity concentrations, it is shown that observations of 7Be is helpful in the study of environmental radioactivity as a tracer for air circulation. (author)

192

Absolute volumetric blood flow measurements using dual-energy digital subtraction angiography.  

Science.gov (United States)

In recent years, as a solution to the well-documented problems associated with visual interpretation of coronary arteriograms, more physiologic means of assessing coronary artery stenosis are being investigated. Absolute arterial blood flow assessed as a function of time can be a valuable aid in the analysis of functional significance of arterial lesions and obstructions. An absolute volumetric blood flow measurement technique using a motion immune dual-energy subtraction technique is being investigated, where the kVp and filtration are switched at 30 Hz. The low- and high-energy images are corrected for scatter and veiling glare before subtraction. In this technique, the absolute arterial blood flow is calculated by combining the videodensitometric analysis of spatial and temporal aspects concerning the contrast propagation through the arterial bed using tissue suppressed energy subtracted images. The blood flow measurement technique was validated using a pulsatile pump and a flow chamber imaged over a Humanoid chest phantom. A 20-MHz Doppler flow probe was used to validate the measurement of phasic volumetric blood flow. The measured (M) and known (K) mean blood flow for the entrance vessel technique and the videodensitometric calibration technique were related by M = 1.14K - 0.12 ml/s (r2 = 0.98) and M = 1.12K - 0.23 ml/s (r2 = 0.90), respectively. The results indicate that phasic volumetric blood flow can be measured using a CCD camera in conjunction with real time dual-energy subtraction. PMID:8455517

Molloi, S; Qian, Y J; Ersahin, A

1993-01-01

193

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

194

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.)

195

Characterization of an absolute cryogenic radiometer as a standard detector for radiant-power measurements.  

Science.gov (United States)

An active cavity radiometer of the electrical substitution type with a cone receiver that operates at 2-4 K has been developed for measuring radiant fluxes in the dynamic range of 20 nW to 100 microW within an uncertainty of +/-1% (2sigmalevel). It is a broadband absolute detector with a flat overall absorption efficiency that is >99% for radiation from the visible to long-wavelength IR. The system is designed based on thermal modeling and experimental measurements of concepts. It has been installed in the cryogenic chamber for low-background infrared radiation calibrations at the National Institute of Standards and Technology (NIST) for testing cryogenic blackbody sources, detectors, and optical components. Its time constant, responsivity, and nonequivalence error have been measured. They are in agreement with design predictions. Radiant power measurements of an amplitude-stabilized He-Ne laser beam with the radiometer and an industry standard photodiode detector, QED-200, have been intercompared and found to be in agreement. The intercomparison ratio of the measurements with the absolute cryogenic radiometer and QED-200 was 1.004 in the 75-100-microW range with an uncertainty of 0.5% (the 3sigma level). PMID:20802586

Datla, R U; Stock, K; Parr, A C; Hoyt, C C; Miller, P J; Foukal, P V

1992-12-01

196

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)

197

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

International Nuclear Information System (INIS)

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

198

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)

199

Airborne measurement of radioactivity by learjet 35A  

International Nuclear Information System (INIS)

In case of a radioactive emergency radioactive plumes may be expected in heights up to the tropopause. For this reason aircraft measurements are necessary as a supplement to ground-based measuring sites. The authors present an aircraft type learjet 35A used for localizing and analyzing radioactive contaminated air masses up to 12,000 m. The aircraft is equipped with an isokinetic high-volume sampler to collect aerosols on filters outside the pressurized cabin and an onboard gamma spectrometry system with a high purity germanium detector to analyze the filters during flight as well as a dose ratemeter, a radon daughter monitor and equipment to collect gaseous iodine and noble gases. The meteorological parameters temperature, atmospheric pressure, relative humidity, wind speed and wind direction are determined as well. Resulting data are transmitted from the plane to the headquarter of the German Meteorological Service (Deutscher Wetterdienst, DWD) and used for verifying the prognosis. (orig.)

200

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)

201

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 %.

202

Study on measurement of trace radioactivity, (2)  

International Nuclear Information System (INIS)

The method was worked out so as to measure 59Fe, 60Co, 65Zn, 95Zr, and 144Ce successively from the same sample by ion-exchange separation. This method was also applicable to the measurement of 90Sr and 137Cs. It was confirmed that 131I in milk could be measured satisfactorily by the method of US Atomic Energy Commission, when raw milk before processing was preserved in good condition. 3H in natural water can be measured with a gas magnifying counter without isotope concentration when water is transformed into hydrogen gas. It was found that an external heater type reactor is desirable to transform 3H in water into methane gas so far as the repair is concerned. The present reactor needs some improvement, however, to get better yield as the best synthesizing yield for methane gas obtained so far was only 48.8%. (Kobatake, H.)

203

Measurement of steam velocity using radioactive tracers  

International Nuclear Information System (INIS)

Measurements of steam velocity are to be carried out on completion of the Ohaki geothermal power station to calibrate a Venturi meter to be used there for assessing generation efficiency. This report describes the development of the measurement method, designed to conform as much as possible to the appropriate British standard, and two tests of it that were carried out under similar conditions at the Wairakei power station. The experience gained will enable the measurements at Ohaki to be carried out in the most efficient manner possible. Although there were only two runs in which the full detection system and the full amount of tracer were used it maybe concluded that the measurements will yield values within +-1% of the true velocities

204

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)

205

Krypton-85 and other airborne radioactivity measurements throughout Ireland  

International Nuclear Information System (INIS)

In compliance with articles 35 and 36 of the EURATOM Treaty, the Radiological Protection Institute of Ireland (RPII) undertakes a comprehensive programme of radioactivity monitoring in the Irish terrestrial environment. Radioactivity is present in the terrestrial environment due to natural processes, the testing of nuclear weapons in the atmosphere, accidents such as the Chernobyl accident and the routine discharge of radionuclides from nuclear installations. The RPII monitors airborne radioactivity concentrations at ten stations throughout Ireland, of which, nine are equipped with low volume particulate samplers and one, in Dublin, with a high volume particulate sampler. The low volume particulate samples are assessed for total beta activity and high volume samples for gamma emitting radionuclides such as caesium-137 and beryllium-7. In addition, air sampled at the RPII laboratory in Dublin, is monitored for krypton-85, a radioactive noble gas, released into the environment primarily as a result of the reprocessing of nuclear fuel at installations such as Sellafield in the UK and La Hague in France. Since the inception of the krypton measurements in 1993 a trend of increasing atmospheric concentrations has been observed. The results of the krypton-85 monitoring, as well as the airborne radioactivity concentration measurements, will be presented and discussed in this paper. (author)

206

Early warning against airborne radioactivity in Bavaria. Measuring network for radioactive immissions  

International Nuclear Information System (INIS)

During the Chernobyl accident it became evident that there was no up to date information of the radiological situation in Bavaria as a whole. Therefore an online measuring network was implemented, which provides radioactivity data around the clock from all over Bavaria. It comprises measuring devices for gamma-dose rate, airborne aerosol and iodine activity and precipitation. The data are processed in accessory computers and transferred to the main network computers in Augsburg by means of a subcenter computer at the site of the IfR-station. Alarm levels are low in order to have an early warning against airborne radioactivity. New techniques for remote maintenance of the measuring devices and nuclide identification are being planned and tested. (orig.)

207

Improved Measurement of Absolute Hadronic Branching Fractions of the Ds+ Meson  

CERN Document Server

The branching fractions of Ds meson decays serve to normalize many measurements of processes involving charm quarks. Using 586 pb^-1 of e+ e- collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for 13 Ds decays in 16 reconstructed final states with a double tag technique. In particular we make a precise measurement of the branching fraction B(Ds -> K- K+ pi+) = (5.55 +- 0.14 +- 0.13)%, where the uncertainties are statistical and systematic respectively. We find a significantly reduced value of B(Ds -> pi+ pi0 eta') compared to the world average, and our results bring the inclusively and exclusively measured values of B(Ds -> eta' X)$ into agreement. We also search for CP-violating asymmetries in Ds decays and measure the cross-section of e+ e- -> Ds* Ds at Ecm = 4.17 GeV.

Onyisi, P U E; Cinabro, D; Smith, M J; Zhou, P; Naik, P; Rademacker, J; Edwards, K W; Briere, R A; Vogel, H; Rosner, J L; Alexander, J P; Cassel, D G; Das, S; Ehrlich, R; Gibbons, L; Gray, S W; Hartill, D L; Heltsley, B K; Kreinick, D L; Kuznetsov, V E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Sun, W M; Yelton, J; Rubin, P; Lowrey, N; Mehrabyan, S; Selen, M; Wiss, J; Libby, J; Kornicer, M; Mitchell, R E; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Hietala, J; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Xiao, T; Powell, A; Thomas, C; Wilkinson, G; Asner, D M; Tatishvili, G; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Napolitano, J; Ecklund, K M; Insler, J; Muramatsu, H; Pearson, L J; Thorndike, E H; Artuso, M; Blusk, S; Mountain, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M

2013-01-01

208

Absolute Density Calibration Cell for Laser Induced Fluorescence Erosion Rate Measurements  

Science.gov (United States)

Flight qualification of ion thrusters typically requires testing on the order of 10,000 hours. Extensive knowledge of wear mechanisms and rates is necessary to establish design confidence prior to long duration tests. Consequently, real-time erosion rate measurements offer the potential both to reduce development costs and to enhance knowledge of the dependency of component wear on operating conditions. Several previous studies have used laser-induced fluorescence (LIF) to measure real-time, in situ erosion rates of ion thruster accelerator grids. Those studies provided only relative measurements of the erosion rate. In the present investigation, a molybdenum tube was resistively heated such that the evaporation rate yielded densities within the tube on the order of those expected from accelerator grid erosion. This work examines the suitability of the density cell as an absolute calibration source for LIF measurements, and the intrinsic error was evaluated.

Domonkos, Matthew T.; Stevens, Richard E.

2001-01-01

209

Recent improvements of ISOLTRAP Absolute mass measurements of exotic nuclides at $10^{-8}$ precision  

CERN Document Server

In the past three years, the sensitivity and the performance of the Penning trap mass spectrometer ISOLTRAP have been enhanced significantly. These improvements, which range from technical developments to systematic studies of the various factors contributing to the uncertainty of the final mass result, now allow mass measurements of short-lived radionuclides with half-lives of less than 100 ms and with a precision of better than 10^-8. Using a newly developed carbon cluster ion source, ISOLTRAP can perform absolute mass measurements relative to the microscopic mass standard ^12C. These developments are reviewed as pertaining to the extension of ISOLTRAP mass measurements to higher precision and shorter half-lives and to molecular mass measurements. PACS: 07.75.+h (Mass spectrometers and related techniques), 21.10.Dr (Binding energies and masses), 32.10.Bi (Atomic masses, mass spectra, abundances, and isotopes), 36.40.Wa (Charged clusters).

Kellerbauer, A G

2003-01-01

210

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

211

MRA calibration and measurement capabilities--radioactivity.  

Science.gov (United States)

The practical realisation of the Mutual Recognition Arrangement relies on its two main Appendices, B and C. Appendix B relates to the equivalence of national measurement standards. The dissemination of these standards is achieved by the provision of physical standards and measurement services, where the associated measurement values are traceable to the SI. Appendix C specifies the quantities and ranges for which participating institutes recognise the validity of calibration and measurement certificates issued by other participating institutes and these are detailed in the database devoted to these standards and services, commonly referred to as calibration and measurement capabilities. Each participating institute has the opportunity to submit entries, via its Regional Metrology Organisation (RMO), to the database but, in order for users to be able to make informed choices, it is important that the data are entered to a common standard. The Joint Committee of the RMOs and the Bureau International des Poids et Mesures is responsible for the coordination of data provided by the RMOs. It is for individual RMOs to ensure the correctness of their own entries and to review and comment on those from others. This paper details that process and describes the various entries in the tables. It also addresses some of the remaining issues that still need to be resolved, in particular, the magnitudes of uncertainties and the need for supporting comparisons, both of which still present some significant problems. PMID:14987630

Woods, M J

2004-01-01

212

Aerial measurements of radioactivity in the environment  

International Nuclear Information System (INIS)

This paper describes an aerial measuring system. Nuclide specific measurements of soil contamination are performed by employing a computerized gamma ray spectrometer with a high purity Ge-detector. At an altitude of 100 m, soil contaminations of some kBq/m2 of 137Cs can be measured. For the detection of sources of gamma radiation, a 12 l NaI(Tl)-detector is used. At a flight path distance of 300 m and a flight speed of 100 km/h, an area of approximately 30 km2 can be covered per hour, whereby gamma radiation sources of an activity of some GBq are still detectable from an altitude of 100 m. A satellite-navigation system is used to determine the position of the helicopter. The altitude above ground is continuously measured by radar altimeter. The results of the German team participating in an international intercomparison measuring campaign in Finland in 1995 are reported. The objective was to determine the 137Cs soil contamination in a given region and to detect unknown radiation sources and to assess their activity. (orig.)

213

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

OpenAIRE

Photoionization spectra have been recorded in the 4s, 4p and 3d resonance regions for the Kr Iisoelectronic sequence using both the dual laser produced plasma 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 new 4p " ns, md transitions are identified with the aid of Hartree-Fock calc...

Kilbane, Deirdre; Folkmann, F.; Banahan, Caroline; Scully, S.; Kjeldsen, H.; Kampen, Paul; Mansfield, M. W. D.; Costello, John T.; West, J. B.

2007-01-01

214

Absolute length measurement with the frequency comb of a femtosecond laser  

International Nuclear Information System (INIS)

We report exploiting the frequency comb of a femtosecond laser as a means of realizing the time-based SI definition of the meter for length metrology. Specifically, an external-cavity diode laser is continuously tuned to a stabilized frequency comb, and its output frequency is modulated over an extensive range to measure the absolute value of a given length by means of multi-wavelength optical interferometry. This approach could find applications in establishing practical length standards with a small amount of uncertainty directly traceable to time standards

215

Absolute efficiency measurements with the {sup 10}B based Jalousie detector  

Energy Technology Data Exchange (ETDEWEB)

The {sup 10}B based Jalousie detector is a replacement for {sup 3}He counter tubes, which are nowadays less affordable for large area detectors due to the {sup 3}He crisis. In this paper we investigate and verify the performance of the new {sup 10}B based detector concept and its adoption for the POWTEX diffractometer, which is designed for the detection of thermal neutrons with predicted detection efficiencies of 75–50% for neutron energies of 10–100 meV, respectively. The predicted detection efficiency has been verified by absolute measurements using neutrons with a wavelength of 1.17 ? (59 meV)

Modzel, G., E-mail: modzel@physi.uni-heidelberg [Physikalisches Institut, Universität Heidelberg, Neuenheimer Feld 226, 69120 Heidelberg (Germany); Henske, M. [CDT CASCADE Detector Technologies GmbH, Hans-Bunte-Str. 8–10, 69123 Heidelberg (Germany); Houben, A. [Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen (Germany); Klein, M. [Physikalisches Institut, Universität Heidelberg, Neuenheimer Feld 226, 69120 Heidelberg (Germany); CDT CASCADE Detector Technologies GmbH, Hans-Bunte-Str. 8–10, 69123 Heidelberg (Germany); Köhli, M.; Lennert, P. [Physikalisches Institut, Universität Heidelberg, Neuenheimer Feld 226, 69120 Heidelberg (Germany); Meven, M. [Heinz Maier-Leibnitz Zentrum (MLZ), 85747 Garching (Germany); Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS), Outstation at MLZ, 85747 Garching (Germany); Schmidt, C.J. [CDT CASCADE Detector Technologies GmbH, Hans-Bunte-Str. 8–10, 69123 Heidelberg (Germany); GSI Detector Laboratory, Planckstr. 1, 64291 Darmstadt (Germany); Schmidt, U. [Physikalisches Institut, Universität Heidelberg, Neuenheimer Feld 226, 69120 Heidelberg (Germany); Schweika, W. [Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS), 52425 Jülich (Germany); European Spallation Source ESS AB, SE-22100 Lund (Sweden)

2014-04-11

216

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

International Nuclear Information System (INIS)

We have measured the cross section of the photoneutron reaction channel 7Li+??6Li(g.s.)+n where the progeny nucleus is the ground state of 6Li. 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.

217

Measurements of the absolute branching fractions of B+/- --> K+/-X(cc).  

Science.gov (United States)

We study the two-body decays of B+/- mesons to K+/- and a charmonium state X(cc) in a sample of 210.5 fb(-1) of data from the BABAR experiment. We perform measurements of absolute branching fractions beta(B+/- --> K+/-X(cc)) using a missing mass technique, and report several new or improved results. In particular, the upper limit beta(B+/- --> K+/- X(3872)) 4.2% will help in understanding the nature of the recently discovered X(3872). PMID:16486923

Aubert, B; Barate, R; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Pappagallo, M; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Chevalier, N; Cottingham, W N; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Teodorescu, L; Blinov, A E; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Weinstein, A J R; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Minamora, J S; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Andreassen, R; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q; Altenburg, D; Feltresi, E; Hauke, A; Spaan, B; Brandt, T; Brose, J; Dickopp, M; Klose, V; Lacker, H M; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Bernard, D; Bonneaud, G R; Grenier, P; Schrenk, S; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Wu, J; Dubitzky, R S; Langenegger, U; Marks, J; Schenk, S; Uwer, U; Schott, G; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Gaillard, J R; Nash, J A; Nikolich, M B; Vazquez, W Panduro; Chai, X; Charles, M J; Mader, W F; Mallik, U; Mohapatra, A K; Ziegler, V; Cochran, J; Crawley, H B; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Arnaud, N; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Oyanguren, A; Petersen, T C; Plaszczynski, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Parry, R J; Payne, D J; Schofield, K C; Touramanis, C; Cormack, C M; Di Lodovico, F; Menges, W; Sacco, R; Brown, C L; Cowan, G; Flaecher, H U; Green, M G; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Edgar, C L; Hodgkinson, M C; Kelly, M P; Lafferty, G D; Naisbit, M T; Williams, J C; Chen, C; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Kofler, R; Koptchev, V B; Li, X; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Viaud, B; Nicholson, H; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Pulliam, T

2006-02-10

218

Absolute beam flux measurement at NDCX-I using gold-melting calorimetry technique  

Energy Technology Data Exchange (ETDEWEB)

We report on an alternative way to measure the absolute beam flux at the NDCX-I, LBNL linear accelerator. Up to date, the beam flux is determined from the analysis of the beam-induced optical emission from a ceramic scintilator (Al-Si). The new approach is based on calorimetric technique, where energy flux is deduced from the melting dynamics of a gold foil. We estimate an average 260 kW/cm2 beam flux over 5 {micro}s, which is consistent with values provided by the other methods. Described technique can be applied to various ion species and energies.

Ni, P.A.; Bieniosek, F.M.; Lidia, S.M.; Welch, J.

2011-04-01

219

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)

220

Absolute measurement of the nitrogen fluorescence yield in air between 300 and 430 nm  

International Nuclear Information System (INIS)

The nitrogen fluorescence induced in air is used to detect ultra-high-energy cosmic rays (UHECR) and to measure their energy. The precise knowledge of the absolute fluorescence yield is the key quantity to improve the accuracy on the cosmic ray energy. The total yield has been measured in dry air using a 90Sr source and a [300-430 nm] filter. The fluorescence yield in air is 4.23±0.21 photons/m when normalized to 760 mmHg, 15 oC and with an electron energy of 0.85 MeV. This result is consistent with previous experiments made at various energies, but with an accuracy improved by a factor of about 3. For the first time, the absolute continuous spectrum of nitrogen excited by 90Sr electrons has also been measured with a spectrometer. Details of this experiment are given in one of the author's Ph. D. thesis [G. Lefeuvre, Ph. D. Thesis, Paris 7 University, 2006 (Ref: APC-26-06) .

221

Absolute specific heat measurements of a microgram Pb crystal using ac nanocalorimetry  

International Nuclear Information System (INIS)

Heat capacity measurements using the ac steady state method are often considered difficult to provide absolute accuracy. By adjusting the working frequency to maintain a constant phase and using the phase information to obtain the heat capacity, we have found that it is possible to achieve good absolute accuracy. Here we present a thermodynamic study of a ? 2.6 ?g Pb superconducting crystal to demonstrate the newly opened capabilities. The sample is measured using a differential membrane-based calorimeter. The custom-made calorimetric cell is a pile of thin film Ti heater, insulation layer and Ge1?xAux thermometer fabricated in the center of two Si3N4 membranes. It has a background heat capacity c = 7.21 K has a width asymp 20 mK and displays no upturn in C. From the heat capacity jump at Tc and the extrapolated Sommerfeld term we find ?C/?Tc 2.68. The latent heat curve obtained from the zero field heat capacity measurement, and the deviations of the thermodynamic critical field from the empirical expression Hc = Hc (0) [1 ? (T/Tc)2] are discussed. Both analyses give results in good agreement with literature.

222

Repeated absolute gravity measurements for monitoring slow intraplate vertical deformation in Western Europe  

Science.gov (United States)

In continental plate interiors, ground surface movements are at the limit of the noise level and close to or below the accuracy of current geodetic techniques. Absolute gravity measurements are valuable to quantify slow vertical movements, as this instrument is drift free and, unlike GPS, independent of the terrestrial reference frame. Repeated absolute gravity (AG) measurements have been performed in Oostende (Belgian coastline) and at 8 stations along a southwest-northeast profile across the Belgian Ardennes and the Roer Valley Graben (Germany), in order to estimate the tectonic deformation in the area. The AG measurements, repeated once or twice a year, can resolve elusive gravity changes with a precision better than 3.7 nm/s2/yr (95% confidence interval) after 11 years, even in difficult conditions. After 8-15 years (depending on the station), we find that the gravity rates of change lie in the [-3.1, 8.1] nm/s2/yr interval and result from a combination of anthropogenic, climatic, tectonic, and Glacial Isostatic Adjustment (GIA) effects. After correcting for the GIA, the inferred gravity rates and consequently, the vertical land movements, reduce to zero within the uncertainty level at all stations except Jülich (due to man-induced subsidence) and Sohier (possibly, an artefact due to the shortness of the time series at that station).

Van Camp, M. J.; de Viron, O.; Scherneck, H.; Hinzen, K. G.; Williams, S. D.; Lecocq, T.; Quinif, Y.; Camelbeeck, T.

2011-12-01

223

First measurements of the absolute neutron spectrum using the magnetic recoil spectrometer at OMEGA (invited)  

International Nuclear Information System (INIS)

A neutron spectrometer, called a magnetic recoil spectrometer (MRS), has been built and implemented at the OMEGA laser facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] for absolute measurements of the neutron spectrum in the range of 6-30 MeV, from which fuel areal density (?R), ion temperature (Ti), and yield (Yn) can be determined. The results from the first MRS measurements of the absolute neutron spectrum are presented. In addition, measuring ?R at the National Ignition Facility (NIF) [G. H. Miller et al., Nucl. Fusion 44, S228 (2004)] will be essential for assessing implosion performance during all stages of development from surrogate implosions to cryogenic fizzles to ignited implosions. To accomplish this, we are also developing an MRS for the NIF. As much of the research and development and instrument optimization of the MRS at OMEGA are directly applicable to the MRS at the NIF, a description of the design and characterization of the MRS on the NIF is discussed as well.

224

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.)

225

Measures of the radioactivity in the environment  

International Nuclear Information System (INIS)

Following the regulation, the radiation doses concerning the population must be estimated. Standards have thus been elaborated to describe reference methods useful to implement measure techniques. This book will allow to realize control analysis, to evaluate the contamination and also to reach to the audit of a site. (A.L.B.)

226

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)

227

Periods Detected During Analysis of Radioactivity Measurements Data  

OpenAIRE

Analysis results of data of long-term radioactivity measurements of 3H, 56Mn, 32Si, 36Cl, 60Co, 137Cs, 90Sr-90Y, 226Ra, 238Pu and 239Pu sources are presented. For beta-radioactive sources, their activity in addition to the exponential drop is characterized by rhythmic variations with a period of 1 year and magnitude of 0.1-0.35% from the average value. These oscillations attain maximum values between January and March, with corresponding minimum values occurring from July to...

Parkhomov, A. G.

2010-01-01

228

Natural radioactivity measurements in building materials used in Samsun, Turkey.  

Science.gov (United States)

In this study, radioactivity levels of 35 different samples of 11 commonly used building materials in Samsun were measured by using a gamma spectrometry system. The analysis carried out with the high purity Germanium gamma spectrometry system. Radioactivity concentrations of (226)Ra, (232)Th and (40)K range from 6 to 54 Bq kg(-1), 5 to 88 Bq kg(-1) and 6 to 1070 Bq kg(-1), respectively. From these results, radium equivalent activities, gamma indexes, absorbed dose rates and annual effective doses were calculated for all samples. Obtained results were compared with the available data, and it was concluded that all the investigated materials did not have radiological risk. PMID:23520200

Tufan, M Çagatay; Disci, Tugba

2013-01-01

229

Representativeness of atomspheric radioactivity measuring points  

International Nuclear Information System (INIS)

The concentrations of radon (Rn), thoron (Tn) and their daughters in the atmosphere vary largely depending on conditions such as geology, topography and atmospheric circulation. Though results are available on the time variation and vertical distribution of Rn daughters, the difference with places has been scarcely studied. In order to clarity the representativeness of measuring points and the difference with places, Rn concentration was measured at two points simultaneously, and also the data on the seasonal variation of Rn concentration were obtained. The results are as follows: much difference was not found between Rn and its daughters; in Rn daughters, some difference was observed seasonally in summer and from autumn to winter; and similar variation was seen within the radius of about 3 km. (Mori, K.)

230

Absolute measurement of the relativistic magnetic dipole transition energy in heliumlike argon.  

Science.gov (United States)

The 1s2s (3)S(1)?1s(2) (1)S(0) relativistic magnetic dipole transition in heliumlike argon, emitted by the plasma of an electron-cyclotron resonance ion source, has been measured using a double-flat crystal x-ray spectrometer. Such a spectrometer, used for the first time on a highly charged ion transition, provides absolute (reference-free) measurements in the x-ray domain. We find a transition energy of 3104.1605(77) eV (2.5 ppm accuracy). This value is the most accurate, reference-free measurement done for such a transition and is in good agreement with recent QED predictions. PMID:23006085

Amaro, Pedro; Schlesser, Sophie; Guerra, Mauro; Le Bigot, Eric-Olivier; Isac, Jean-Michel; Travers, Pascal; Santos, José Paulo; Szabo, Csilla I; Gumberidze, Alexandre; Indelicato, Paul

2012-07-27

231

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.

232

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

233

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

234

Absolute measurement of radiative and Auger rates of K -shell-vacancy states in highly charged Fe ions  

Science.gov (United States)

We present absolute measurements of radiative and Auger decay rates of K -shell vacancies in highly charged iron ions. The ions were resonantly excited with monochromatic x rays from the PETRA III synchrotron source. By measuring x-ray fluorescence and Auger decay simultaneously, absolute transition rates could be determined independently of most experimental parameters. The results confirm theoretical calculations, which are essential to model the photoexcited plasmas in x-ray binary stars and active galactic nuclei.

Steinbrügge, R.; Bernitt, S.; Epp, S. W.; Rudolph, J. K.; Beilmann, C.; Bekker, H.; Eberle, S.; Müller, A.; Versolato, O. O.; Wille, H.-C.; Yava?, H.; Ullrich, J.; Crespo López-Urrutia, J. R.

2015-03-01

235

Measurements of radioactivity in foodstuffs around Kakrapar Atomic Power Station  

International Nuclear Information System (INIS)

Radioactivity content of 137Cs and 90Sr in various diet components grown and consumed locally around Kakrapar Atomic Power Station (KAPS) site have been measured. To find out the possibility of radioactivity contribution from KAPS, two groups consisting of five villages each have been selected on the basis of distance from the plant site. Group - 1 (within 1.5 to 5.0 Km radius) was used to find out plant related activity, while Group-II located away from the plant (beyond 16 Km) were considered for the control study. Results revealed that radioactivity content of 137Cs and 90Sr in various diet components did not show any significant variation for both the group of villages. (author)

236

Radioactive Aerosol Size Distribution Measured in Nuclear Workplaces  

International Nuclear Information System (INIS)

Inhalation is the main route for internal exposure of workers to radioactive aerosols in the nuclear industry.Aerosol's size distribution and in particular its activity median aerodynamic diameter (AMAD)is important for determining the fractional deposition of inhaled particles in the respiratory tract and the resulting doses. Respiratory tract models have been published by the International Commission on radiological Protection (ICRP).The former model has recommended a default AMAD of 1 micron for the calculation of dose coefficients for workers in the nuclear industry [1].The recent model recommends a 5 microns default diameter for occupational exposure which is considered to be more representative of workplace aerosols [2]. Several researches on radioactive aerosol's size distribution in nuclear workplaces has supported this recommendation [3,4].This paper presents the results of radioactive aerosols size distribution measurements taken at several workplaces of the uranium production process

237

Radioactivity measurements for the thin layer activation technique  

International Nuclear Information System (INIS)

Thin layer activation (TLA) is one of the promising techniques employing radiotracers at low levels of radioactivity for material performance studies such as wear and corrosion. The principle of TLA is the creation of an appropriate radionuclide in a given material to a well defined depth of a selected area. This activation is realised by exposure of the component to a charged particle beam using, e.g., a cyclotron facility. If the material is subjected to mechanical or chemical degradation, any loss of the activated material will result in a loss in radioactivity of the activated component. The sensitivity of TLA technique is high due to the capability of low level radioactivity measurement performed by ? spectrometry. The sensitivity of TLA is below 0.1 ?m thickness loss or 1 ng mass loss. In the present paper, some applications of TLA in ongoing research at the Institute for Health and Consumer Protection of the European Commission are presented

238

(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

239

Measuring system for radioactivity of labelled biopolymers  

International Nuclear Information System (INIS)

The apparatus incorporates a steel container for samples of biological biopolymers in conjunction with a co-precipitator, filtration unit and scintillator. An electrical drive is employed for stepwise movements of the system. A control unit is included for regulation of the degree of radio activity. The various reagents are contained in separate vessels. A vacuum pump is employed for the filtration process. The measuring cylinder is a hollow unit made of polyfluoroethylene with end surfaces of film of the same material. Carbon dioxide under presure is used as a control medium. (G.C.)

240

Tectonic, Climatic and Anthropogenic Vertical Land Movements in Western Europe by Repeated Absolute Gravity Measurements  

Science.gov (United States)

In continental plate interiors, tectonic deformations are small and the associated ground surface movements remain close to or below the accuracy of current geodetic techniques, and at the limit of the noise level. An absolute gravimeter is an appropriate tool to quantify slow vertical movements, as this instrument, based on length and time standards, is drift free and does not depend on any terrestrial reference frame. Repeated absolute gravity (AG) measurements have been performed in Oostende (Belgian coastline) and at 8 stations along a southwest-northeast profile across the Belgian Ardennes and the Roer Valley Graben (Germany), in order to estimate the tectonic deformations in the area. After 7-13 years (depending on the station), we find evidence that the movements are no larger than a few millimeter per year and result from a combination of anthropogenic, climatic, tectonic, and Glacial Isostatic Adjustment (GIA) effects. This demonstrates the importance of precisely modeling the GIA effects in order to investigate intraplate tectonic deformations at the sub-millimeter level. This study also shows that AG measurements, repeated once or twice a year, can resolve vertical velocities at the 1.0 mm/yr level after 10 years, even in difficult conditions, provided that the gravimeter is carefully maintained.

van Camp, M. J.; de Viron, O.; Lecocq, T.; Hinzen, K. G.; Quinif, Y.; Williams, S. D.; Camelbeeck, T.

2010-12-01

241

Absolute and relative isotope abundances measured by tunable diode laser spectroscopy  

International Nuclear Information System (INIS)

The potential for measuring absolute and relative isotope abundances by high resolution spectroscopy with tunable diode lasers as sources was studied. In order to achieve the sensitivity necessary to determine the absolute abundances of molecules containing long-lived radionuclides such as 14C and 129I, a resonant spectrophone based on the photoacoustic effect was used for detection. For safety, NH3 was used as a sample with air as a buffer gas when characterizing the performance of the TDL-spectrophone system. Frequency modulation of the TDL was employed. The optimum operating pressure was found to be 6.6 kPa(50 Torr). Substitution of Kr as a buffer gas yielded a fourfold increase in signal. It is estimated that with currently available TDLs a photoacoustic spectrometer should be capable of detecting 14CO2 and CH129I at the levels present in nuclear reactor containment gases. An isotope shift of CH3129I relative to CH3127I in the nu6 band of (0.0135 +/- 0.0006) cm-1 was measured by TDL linear absorption spectroscopy

242

An alternative approach to wavelength modulation spectroscopy for absolute measurements of gas parameters in industrial processes  

Science.gov (United States)

Wavelength modulation spectroscopy (WMS) with tunable diode lasers (TDLs) is the preferred technique for gas composition measurement in a growing number of industrial process control applications. Those systems using optical fiber cables or networks to address single or multiple sensing points are of particular interest. However, the conventional approaches suffer from a number of calibration / scaling factor issues which, although addressable, lead to added cost and accumulated errors in the final determination of gas concentration. Such issues are particularly problematic in industrial applications where the pressure may be varying and unknown. The target signal in WMS is an amplitude modulation (AM) component generated by the interaction of frequency modulation (FM) on the laser output with a rotational / vibrational gas absorption line function. However, direct laser amplitude modulation is also present and distorts the recovered target signals again leading to errors. Here we report an alternative approach in which we exploit the phase difference between the laser AM and the FM to provide direct recovery of the absolute gas absorption line function from which both the gas concentration and the pressure may be obtained from the depth and line width respectively. The method is absolute with no need for calibration thus eliminating the difficulties with the conventional approach. In our presentation, we report the basic principles of the technique and its experimental validation through a number of methane gas concentration and pressure measurements.

Johnstone, Walter; Duffin, Kevin; McGettrick, Andrew; Stewart, George

2007-09-01

243

Application of the 4 pigammaMethod to the Absolute Standardization of Radioactive Sources of Positron Emitters  

International Nuclear Information System (INIS)

We discuss the application of the method known as 4 pigammacountingto the standardization of positron emitters. Monte Carlo simulations are used to calculate the detection efficiency of positrons emitted by the nuclides 22Na and 18F. Two experimental setups are used, both based on a NaI(Tl) well detector. The results of the standardizations are in good agreement with those obtained by other methods. It is shown that the 4 pigammamethod can be successfully used for the absolute standardization of sources of positron emitters. (Author) 23 refs

244

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

245

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%.

246

Absolute electron-scattering total cross section measurements for noble gas atoms and diatomic molecules  

International Nuclear Information System (INIS)

Absolute electron-scattering total cross sections for noble gas atoms (He, Ne, Ar, Kr, and Xe) and H2, N2, CO, NO, and O2 molecules have been measured at impact energies between 0.5 and 250 eV by the linear transmission method with the same experimental set-up for all the investigated targets. Generally, our total cross sections have been found to be in good agreement with other data with respect to shape. Some systematic discrepancies in magnitude still exist between results of different groups, especially at the lowest applied energies and in the energy range where the cross sections peak. At these energies, new measurements should be carried out before establishing a reference set of data. (orig.)

247

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

248

Absolute frequency measurements on the 2S --> 3S transition of lithium-6,7  

Energy Technology Data Exchange (ETDEWEB)

The frequencies of the 2S–3S two-photon transition for the stable lithium isotopes were measured by cavity-enhanced Doppler-free laser excitation that was controlled by a femtosecond frequency comb. The resulting values of 815 618 181.57(18) and 815 606 727.59(18) MHz, respectively, for 7Li and 6Li are in agreement with previous measurements but are more accurate by an order of magnitude. There is still a discrepancy of about 11.6 and 10.6MHz from the latest theoretical values. This is comparable to the uncertainty in the theoretical calculations, while uncertainty in our experimental values is more than a hundred-fold smaller. More accurate theoretical calculation of the transition frequencies would allow extraction of the absolute charge radii for these stable isotopes, which in turn could improve nuclear charge radii values for the unstable lithium isotopes.

Sanchez, R.; Zakova, Monika; Andejelkovic, Zoran; Bushaw, Bruce A.; Dasgupta, Kamalesh; Ewald, G.; Geppert, C. H.; Kluge, H. J.; Kramer, Jorg; Nothhelfer, Matthias; Tiedemann, Dirk; Winters, Danyal F.; Nortershauser, W.

2009-07-03

249

A method to measure the absolute branching fractions of ?{sub c} decays  

Energy Technology Data Exchange (ETDEWEB)

It is proposed to exploit the decay of the meson B{sup +} ? p?{sup +}?{sup +} ?{sub c}{sup --} and of its charge conjugate B{sup -} copiously produced at LHC to obtain a sample of ?{sub c} baryons through the strong decay ?{sub c} ? ?{sub c}?. 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 ?{sub c} baryon into p K? 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. (orig.)

Contu, A.; Fonnesu, D.; Oldeman, R.G.C.; Saitta, B.; Vacca, C. [Cagliari Univ. (Italy). Dipt. di Fisica; INFN, Cagliari (Italy)

2014-12-01

250

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

251

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

252

Absolute alpha activity measurements of some plants growing in monazite bearing soils in Sri Lanka  

International Nuclear Information System (INIS)

Deposits of monazite bearing soils occur along the Southwest, West and East Coasts of Sri Lanka. High levels of gamma activity in some plant species growing in the West Coast have been reported. The high levels were due to the presence of the daughter nuclides of 232Th, most of which are alpha emitters. Absolute alpha activity measurements of ash samples of some plants growing in monazite bearing soils were carried out using the alpha sensitive polymeric nuclear track detector CR-39. The values ranged from 60-1900 mBq/g and were in good agreement with the values obtained from conventional scintillation counting method. The activity concentration of 228Th in the ash samples was also calculated by measuring the activity concentration of emanated thoron trapped inside a glass bottle with the use of a CR-39 track detector. (author)

253

A method to measure the absolute branching fractions of ?c decays  

International Nuclear Information System (INIS)

It is proposed to exploit the decay of the meson B+ ? p?+?+ ?c-- and of its charge conjugate B- copiously produced at LHC to obtain a sample of ?c baryons through the strong decay ?c ? ?c?. 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 ?c baryon into p K? 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. (orig.)

254

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.

255

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

256

Absolute measurement of absorptance in DUV optics from laser-induced wavefront deformations  

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 results for fused silica are presented.

Mann, K.; Leinhos, U.; Sudradjat, J.; Schäfer, B.

2011-12-01

257

Absolute method of measurement of the fast neutron capture cross section by 238U  

International Nuclear Information System (INIS)

The absolute method of measurement of the neutron capture cross section by 238U and 197Au in the 15-480 keV energy range is presented. The method is based on utilization of a large liquid scintillation detector for detecting instantaneous ? rays of the capture events and nanosecond technique of time of flight at a pulsed electrostatic generator for determination of neutron energy and background discrimination. The method is realized on a fast and resonance neutron spectrometer on the basis of the PEI EG-1. Preliminary results of measurements of the fast neutron capture cross sections by 238U and 197Au are presented. The cross sections are normalized using the saturated resonance technique

258

Absolute measurement of the thermal conductivity of alcohol + n-hexane mixtures  

Science.gov (United States)

New absolute measurements, by the transient hot-wire technique, of the thermal conductivity of binary mixtures of n-hexane with methanol, ethanol, and hexanol are presented. The temperature range examined was 295 345 K and the pressure atmospheric. The concentrations studied were 75% by weight of methanol and 25, 50, and 75% by weight of ethanol and hexanol. The overall uncertainty in the reported thermal conductivity data is estimated to be ±0.5%, an estimate confirmed by the measurement of the thermal conductivity of water. A recently extended semiempirical scheme for the prediction of the thermal conductivity of mixtures from the pure components is used to correlate and predict the thermal conductivity of these mixtures, as a function of both composition and temperature.

Assael, M. J.; Charitidou, E.

1990-11-01

259

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

260

Physical measurements with high-energy radioactive beams  

International Nuclear Information System (INIS)

Physical measurements were made with high-energy radioactive beams (positron emitters) produced as secondary particles from a heavy-particle accelerator. Data are presented for water-equivalent thickness of a silicon diode, a comparison of Bragg peak ionization depth vs stopping depth, and differential stopping depths when a beam is intercepted by heterogeneous materials in the orthogonal direction. A special positron-emitting beam analyzing (PEBA) system was used in form images of the stopped radioactive beam. These measurements will have direct impact on charged-particle radiotherapy, since the precise range of beams of charged particles to targets within patients can be measured and used for treatment planning. Also, during the treatments the stopping point of the beam can be monitored to verify that the treatment is being delivered as planned

261

Evaluation of uncertainty and detection limits in radioactivity measurements  

International Nuclear Information System (INIS)

The uncertainty associated with the assessment of the radioactive content of any sample depends on the net counting rate registered during the measuring process and on the different weighting factors needed to transform this counting rate into activity, activity per unit mass or activity concentration. This work analyses the standard uncertainties in these weighting factors as well as their contribution to the uncertainty in the activity reported for three typical determinations for environmental radioactivity measurements in the laboratory. It also studies the corresponding characteristic limits and their dependence on the standard uncertainty related to those weighting factors, offering an analysis of the effectiveness of the simplified characteristic limits as evaluated by various measuring software and laboratories

262

Radioactive air effluent emission measurements at two research reactors  

Energy Technology Data Exchange (ETDEWEB)

Sandia National Laboratories operates two reactors which fall under US Environmental Protection Agency regulations for emission of radionuclides to the ambient air. These reactors are: (1) the Annular Core Research Reactor, a pool-type reactor and (2) the Sandia Pulsed Reactor III, a Godiva-type reactor. The annual radioactive air emissions from these two reactors had been estimated based on engineering calculations and used in the facility Safety Analysis Report. The calculated release rates had never been confirmed through measurements. The purpose of this work was to obtain confirmatory radioactive gas and aerosol concentration measurements for radionuclides in exhaust stacks of these reactors during normal operation; however, the measured production rate of argon-41 was significantly different from the engineering calculations for both reactors. The resolution of this difference is discussed.

McDonald, M.J.; Ghanbari, F.; Burger, M.J.; Holm, C.

1996-10-01

263

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)

264

Absolute cross-sectional area measurements in quantitative coronary arteriography by dual-energy DSA.  

Science.gov (United States)

Recent studies have emphasized the limitations of conventional coronary angiography. These limitations include the lack of correlation between the severity of coronary stenosis as estimated from coronary angiograms and the actual severity of stenotic lesions measured in postmortem hearts. As a result, attempts have been made to quantitate luminal dimension more precisely. The application of quantitative digital subtraction angiography (DSA) in the assessment of coronary artery lesion dimension has been limited by cardiac and respiratory motion artifacts. We have reported previously on a motion-immune dual-energy (DE) cardiac mode in which kVp and filtration are switched at 30 Hz. To assess the potential advantages of a videodensitometric technique for quantification of absolute vessel cross-sectional area (CSA), three different quantitative coronary arteriography (QCA) algorithms were compared. The three algorithms under comparison were a videodensitometric (V) algorithm, which does not require any geometric assumption for absolute vessel CSA measurement, and videodensitometric (VC) and edge detection (ED) algorithms, which do require the assumption of circular cross-section for CSA measurements. A cylindrical vessel phantom (0.5-4.75 mm in diameter) and a crescentic vessel phantom, producing 25% to 90% area stenosis, were imaged over the chest of a humanoid phantom. The low- and high-energy images were corrected for scatter and veiling glare before energy subtraction. For CSA measurements in crescentic vessel phantoms, the V algorithm produced significantly improved results (slope = 0.87, intercept = 0.51 mm2, r = .95) when compared to the VC (slope = 1.05, intercept = 4.19 mm2, r = .75) and the ED (slope = 1.57, intercept = 5.21 mm2, r = .60) algorithms. PMID:2055711

Molloi, S Y; Ersahin, A; Roeck, W W; Nalcioglu, O

1991-02-01

265

Testing of an absolute measuring flat jack according to the compensation method (AWID)  

International Nuclear Information System (INIS)

A measurement principle for a flat jack is being introduced by means of which stress measurements may be carried out without requiring any material parameters of the flat jack for the measurements. No calibration measurements are needed for this absolute measuring flat jack. A temperature dependence does not exist. A leap in the electrical resistance of the flat jack, which is brought about by two metal sheets separating when being pumped up with hydraulic oil at reaching of external pressure, is evaluated. Besides theoretical considerations on the mode of operation of the flat jack, laboratory tests were performed in an autoclave as well as in a tube filled with salt grit under a uniaxial press. The error which arose during measurements in the oil pressure autoclave was due to the magnitude of the reading accuracy of the measuring devices, i.e., it was smaller than 0.3% at 150 bars. This is to be considered as the error which may be assigned to the flat jack. Finally an arrangement of six flat jacks is treated for determining stress tensors in the heated area of the Temperature Test Field (TV 6) in the Asse salt mine. 5 refs.; 15 figs

266

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

267

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

268

Absolute Ion-Temperature Measurements in D2 and DT Implosions on OMEGA  

Science.gov (United States)

Measurements of the ion temperature in inertial confinement fusion (ICF) experiments provide valuable information on the state of the compressed fuel to further constrain numerical hydro code simulation models. The neutron-averaged ion temperature in ICF experiments is usually measured by neutron time-of-flight (nTOF) detectors. Accurate measurement of the absolute ion temperature requires an accurate instrument response function (IRF) of the entire nTOF system including the detector, cable, and recording device. The nTOF IRF is typically constructed from measurements and neutron-response simulations. Different methods for measuring nTOF detectors IRF's on OMEGA will be presented. The precision and accuracy of ion-temperature measurements with different nTOF detectors on OMEGA implosions with D2 and DT fuels will be discussed. This work is supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.

Glebov, V. Yu.; Stoeckl, C.; Sangster, T. C.; Forrest, C.; Lerche, R. A.

2012-10-01

269

Study on influences of experimental factors on energy and absolute activity measurements of alpha-emitters  

International Nuclear Information System (INIS)

This work presents firstly a review of the fundamental results and conclusions obtained through alpha-spectrometry and alpha-counting, and the influence of energy straggling, energy loss, self-absorption and backscattering, on the determination of the energy and the absolute activity of alpha samples. Is is shown that the techniques of source fabrication and the methods of measurements play a capital influence on the obtained results. Moreover, measurements made by us, with a silicon surface barrier detector, show that the peak-asymmetry and peak-shift of an alpha-spectrum increases with the angle of emission, and that the magnitude of this effect depends on the thickness and homogeneity of the sample, as well as on the geometry of the measuring system. Through an analysis of the angular distribution of the emitted particles, the degree of isotropy of some thin Am sup(241) sources was measured and the influence of source backing and the geometry was analysed. We can conclude that, in general, there is a larger precision in measurements made under very small solid angles around the normal to the sample, and we enphasize the necessary cares required on the production of the source and on the set up of the measuring system. (author)

270

Measurement of OEF and absolute CMRO2: MRI-based methods using interleaved and combined hypercapnia and hyperoxia  

OpenAIRE

Blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (FMRI) is most commonly used in a semi-quantitative manner to infer changes in brain activity. Despite the basis of the image contrast lying in the cerebral venous blood oxygenation level, quantification of absolute cerebral metabolic rate of oxygen consumption (CMRO2) has only recently been demonstrated. Here we examine two approaches to the calibration of FMRI signal to measure absolute CMRO2 using hypercapnic an...

Wise, Richard G.; Harris, Ashley D.; Stone, Alan; Murphy, Kevin

2013-01-01

271

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

272

A measurement of the absolute neutron beam polarization produced by an optically pumped sup 3 He neutron spin filter  

CERN Document Server

The capability of performing accurate absolute measurements of neutron beam polarization opens a number of exciting opportunities in fundamental neutron physics and in neutron scattering. At the LANSCE pulsed neutron source we have measured the neutron beam polarization with an absolute accuracy of 0.3% in the neutron energy range from 40 meV to 10 eV using an optically pumped polarized sup 3 He spin filter and a relative transmission measurement technique. sup 3 He was polarized using the Rb spin-exchange method. We describe the measurement technique, present our results, and discuss some of the systematic effects associated with the method.

Rich, D R; Crawford, B E; Delheij, P P J; Espy, M A; Haseyama, T; Jones, G; Keith, C D; Knudson, J; Leuschner, M B; Masaike, A; Masuda, Y; Matsuda, Y; Penttilae, S I; Pomeroy, V R; Smith, D A; Snow, W M; Szymanski, J J; Stephenson, S L; Thompson, A K; Yuan, V

2002-01-01

273

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)

274

A gridded ionization chamber for measurement of environmental radioactivity  

International Nuclear Information System (INIS)

In order to detect low level alpha radioactivities in various natural materials, a single gridded ionization chamber was constructed. This chamber of the Frischgrid type has a very large source area of 200 cm2 and provides a resolution of about 79 keV for 5.48 MeV alpha particles of a Americium-241 source. It was attempted to eliminate the background pulses, by making use of cathode pulses. The resultant background counting rate was in the order of 3 counts per hour, which corresponds to a good figure of merit of about 106. As a preliminary measurement, radioactive contamination levels in a sample of aluminum have been measured. It was found that (0.014 +- 0.011) pCi of Radium-226 is contained in 1 gram of the sample. (author)

275

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)

276

Absolute distance measurement by dual-comb interferometry with adjustable synthetic wavelength  

International Nuclear Information System (INIS)

Absolute distances were measured using two femtosecond lasers of different pulse repetition rates by revisiting the dual-comb interferometric method proposed by Coddington et al (2009 Nature Photon. 3 351–6). The apparatus built for experiments was designed to eliminate the dead zones in the measurement range by separating the measurement pulses from the reference pulses using orthogonal polarization. In addition, the pulse repetition rate of the signal laser was made tunable in order to extend the non-ambiguity range (NAR) by adaptively adjusting the synthetic wavelength in consideration of the de facto measurement stability in the air. Actual tests performed in the open air proved that a target distance of 69.3 m is measured without interruptions at a 200 µs update rate in the presence of a ?170 µm drift of the optical path length caused by the fluctuation of the refractive index of air. The proposed hardware system design for effective NAR extension will facilitate the use of dual-comb interferometry for various terrestrial applications. (paper)

277

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

278

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

279

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

280

Is absolute noninvasive temperature measurement by the Pr[MOE-DO3A] complex feasible.  

Science.gov (United States)

Recently, the feasibility of the praseodymium complex of 10-(2-methoxyethyl)-1,4,7,10-tetraaza-cyclododecane-1,4,7-tr iacetate (Pr[MOE-DO3A]) for non-invasive temperature measurement via 1H spectroscopy has been demonstrated. Particularly the suitability of the complex for non-invasive temperature measurements including in vivo spectroscopy without spatial resolution as well as first spectroscopic imaging measurements at low temporal resolution (> or = 4 min) and high temporal resolution (breath hold, approximately 20 s) has been shown. As of today, calibration curves according to the particular experimental conditions are necessary. This work aims to clarify whether the Pr[MOE-DO3A] probe in conjunction with 1H-NMR spectroscopy allows non-invasive absolute temperature measurements with high accuracy. The measurement results from two different representative media, distilled water and human plasma, show a slight but significant dependence of the calibration curves on the surrounding medium. Calibration curves in water and plasma were derived for the temperature dependence of the chemical shift difference (F) between Pr[MOE-DO3A]'s OCH3 and water with F = -(27.53 +/- 0.04) + (0.125 +/- 0.001) x T and F = -(27.61 +/- 0.02) + (0.129 +/- 0.001) x T, respectively, with F in ppm and T in degrees C. However, the differences are minuscule even for the highest spectral resolution of 0.001 ppm/pt, so that they are indistinguishable under practical conditions. The estimated temperature errors are +/- 0.18 degrees C for water and +/- 0.14 degrees C for plasma and with that only slightly worse than the measurement accuracy of the fiber-optical temperature probe (+/- 0.1 degrees C). It can be concluded that the results obtained indicate the feasibility of the 1H spectroscopy method in conjunction with the Pr[MOE-DO3A] probe for absolute temperature measurements, with a maximum accuracy of +/- 0.2 degrees C. PMID:10697226

Hentschel, M; Findeisen, M; Schmidt, W; Frenzel, T; Wlodarczyk, W; Wust, P; Felix, R

2000-02-01

281

Absolute luminosity and proton-proton total cross section measurement for the ATLAS experiment at LHC  

International Nuclear Information System (INIS)

The Large Hadron Collider (LHC) at CERN in Geneva will soon deliver collisions with an energy never reached in a particle accelerator. An energy in the center of mass of 10 and ultimately 14 TeV will allow to go beyond the borders of the physics known so far. ATLAS, the largest detector ever built, will hunt the Higgs boson and search for new physics beyond the Standard Model. Any physical process is described by a cross section that measures its probability to occur. The events resulting from a given process are registered by ATLAS. To determine their according cross section, one has to know the luminosity. For the ATLAS experiment, a relative measurement of the luminosity can be done using the response of several sub-detectors. However to calibrate these detectors, an absolute measurement has to be performed. The ALFA detector has been designed to measure the elastic scattering spectrum that will allow to determine the absolute luminosity and the proton-proton total cross section. This provides an accurate calibration tool at a percent level. These detectors, located 240 m away from the interaction point, are called roman pots, a mechanical system that allows to approach a scintillating fiber tracker a few millimeters to the beam center. The simulation of the measurement requires to use a charged particles transport program. This program has to be carefully chosen because the determination of the protons lost during their travel from the interaction point to the detector has a major impact on the acceptance computation. The systematical uncertainties affecting the luminosity and the total cross section measurements are also determined using the full simulation chain. The ALFA detector operates in a complex environment and consequently its design requires a great care. A large tests campaign has been performed on the front end electronics. The results and the corresponding data analysis have shown that all requirement where fulfilled. A test beam has been preformed at each major step in the detector development. During these periods, the detector has been investigated under all aspects. The tracks reconstruction algorithm, the methods to extract the detection efficiency or the cross talk level are just a part of all the parameters that have to be determined. All these tests have confirmed the technical choices made so far and allowed to launch the serial production of the eight detectors that will be install in 2011 for the luminosity measurement. (author)

282

Surveillance and control of containment by means of radioactive measurements  

International Nuclear Information System (INIS)

In this paper, the radioactive measurements participating in the surveillance and control of the reactor containment as well as the possible procedures or operating rules related to, especially the ultimate procedures which could be implemented in case of a beyond of design accident, are presented. However, an overall view of the plant radiation monitoring system installed on the French plants is first given. If necessary, difference between 900 MW and 1300 MW units are emphasized

283

Radioactivity measurement in imported food and food related items  

International Nuclear Information System (INIS)

The Philippine Nuclear Research Institute (PNRI), formerly Philippine Atomic Energy Commission (PAEC) undertook the radioactivity monitoring of imported food and food-related products after the Chernobyl Plant accident in April 1986. Food samples were analyzed for 137Cs and 134Cs by gamma spectral method of analysis. This report deals with the measurement process and gives the result of the activity covering the period June 1986 to December 1987. (Auth.). 9 tabs., 7 figs., 4 refs

284

Third order time correlation method applied to Silene absolute criticality measurements - 074  

International Nuclear Information System (INIS)

A previous time-list mode experiment performed with SILENE reactor is analyzed using the third order correlation technique. This method originally proposed by A. Furuhashi is an extension to the well known second order Feynman-a technique. The interest of the method is that it allows for the absolute determination of the multiplication coefficient using second and third order moments of the counting number distribution as function of the time gate width. In the framework of the point reactor model the reactivity is related to the measured parameters using a simple formula. In the analyzed SILENE experiment the reactivity given by the Furuhashi method is compatible with MCNP criticality calculation although the accuracy of the method is bad due to the statistical noise in the third order correlation parameter when the counting time is limited. (authors)

285

Absolute Polarization Measurements at RHIC in the Coulomb Nuclear Interference Region  

International Nuclear Information System (INIS)

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

286

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

DEFF Research Database (Denmark)

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.

1996-01-01

287

Coincidence system for the absolute measurement of radionuclides activity using a liquid scintillator  

International Nuclear Information System (INIS)

A system for the standartization of radioisotopes activity using liquid scintillator detector was developed. The system was set up at Nuclear Metrology Laboratory - L.M.N. (Nuclear Physics Division - IEA). The system performance was checked by absolute activity measurements for two radioisotopes, 60Co and 241Am. The activities were determined by the 4?(?, ?-?) coincidence method. An accuracy of the order of 99,8% was obtained. The results for 60Co were compared with those obtained by 4??-? coincidence method using a proportional counter at L.M.N., while the results for 241Am were compared with those obtained through the linear extrapolation method using the same liquid scintillator. Compared to other systems, the advantages of this one are the simplicity and the short time spent in the sample preparation, and the negligible self-absorption. (Author)

288

Absolute spectral response measurements of different photodiodes useful for applications in the UV spectral region  

Science.gov (United States)

Long UV radiation exposure can result in damages of biological tissues, as burns, skin aging, erythema and even melanoma cancer. In the past years an increase of melanoma cancer has been observed and associated to the atmospheric ozone deployment. Attendance of sun tanning unit centers has become a huge social phenomena, and the maximum UV radiation dose that a human being can receive is regulated by law. On the other side, UV radiation is largely used for therapeutic and germicidal purposes. In all these areas, spectroradiometer and radiomenter are needed for monitoring UVA (315-400 nm), UVB (280-315 nm) and UVC (100-280 nm) irradiance. We have selected some commercial photodiodes which can be used as solid state detectors in these instruments. We have characterized them by measuring their absolute spectral response in the 200 - 400 nm spectral range.

Pelizzo, Maria G.; Ceccherini, Paolo; Garoli, Denis; Masut, Pietro; Nicolosi, Piergiorgio

2004-09-01

289

Absolute measurement of thermal neutron fluence and its application for fission track dating  

International Nuclear Information System (INIS)

The absolute measurements of thermal neutron fluence for fission track dating have been developed after the proceeding results of Honda et al. (1987). The 2,200 m/sec activation cross section of 197Au (98.8 barn) is corrected to 87.4 barn (?a) by the three factors of the neutron temperature, Maxwellian distribution of thermal neutrons and non 1/v correction factor for the above absolute measurement. The calibrated factor (Bth) of standard glasses (SRM613, SRM962a, CN-1 and CN-2) and zeta-a (?a) values for fission track dating are determined on the basis of these experimental results. The values of Bth, (7.47 ± 0.29) x 109 for SRM613, (7.43 ± 0.34) x 109 for SRM962a, (2.50 ± 0.06) x 109 for CN-1 and (2.74 ± 0.06) x 109 for CN-2 closely agree with those reported previously by Honda et al. (1987). Further, the ?a values of 392.3 ± 16.5 for SRM962a and SRM613, 131.4 ± 3.1 for CN-1 and 144.1 ± 3.3 for CN-2 calculated from Bth, effective thermal neutron fission cross-section ?f (497.4 barn), isotopic abundance ratio 235U/239U, I (7.2527 x 10-3) and spontaneous fission decay constant of 238U, ?f (6.85 x 10-17a-7) show close agreement with ?b values (392.5 ± 10.0, 131.6 ± 3.3, 140.1 ± 3.5) derived from the absolute age of Fish Canyon Tuff (27.9 ± 0.7 Ma) respectively. The fission track ively. The fission track dating of zircons separated from Oligocene-Miocene tuff distributed in Eastern Hokkaido have been carried out by the external detector method using ?a. The obtained ages are 28.6 ± 0.7 Ma (1 - 2) and 23.3 ± 0.7 Ma (3 - 2). These results agree well with the geologic age supported from Ashoro Fossil Fauna, K-Ar ages of volcanic rocks and stratigraphy in this area. (author)

290

A study on the absolute measurement of ?-ray absorbed dose in the skin depth  

International Nuclear Information System (INIS)

The absolute measurement of ? ray absorbed dose in the skin depth located at the certain distance from the radiation source (90Sr + 90Y, 204TI, 147Pm) recommended by the International Standardization Organization is performed by using an extrapolation chamber in the range of several mGy/h. Since one of critical points in measuring of absorbed dose is to make the environment in chamber similar to tissue, a new approach to the measurement of absorbed dose is proposed. The attenuation difference is minimized by deciding a window thickness such as the attenuation effect in chamber window becomes similar to that in the skin depth. A-150 tissue equivalent plastic, whose structure and density is very similar to tissue, is used for back material. The back scattering effect of both media is measured using the proposed method to calibrate the difference in back scattering effect between back material and tissue. For the measurement of back scattering effect of each material, an ionization chamber, whose structure is very similar to the extrapolation chamber and back material is replaceable, is made. Based on the results, ? ray absorbed dose in the skin depth of 70 ?m was measured as follows : 0.759 ?Gy/s (±3.78% ) for 90Sr + 90Y, 0.173 ?Gy/s (±4.17%) for 204TI and 0.088 ?Gy/s (±7.70%) for 147Pm. In order to evaluate the reliability of the proposed method, the absorbed dose measured in this study is compared to that measured in PTB (Physikalisch Technische Bundesanstalt) for the same ? ray source. Although the proposed method gives slightly higher value, the difference is within 1%. In conclusion, the proposed method seems to make the measuring environment closer to tissue, even though the calibration factor yielded by the proposed method has a little effect on evaluation of absorbed dose

291

Ultra low radioactivity measurements at Modane underground Laboratory  

International Nuclear Information System (INIS)

We present in this paper the activities of the Laboratoire Souterrain de Modane, LSM, and in particular the activity related to Single-Event Rate Errors in semiconductors. The LSM is located in the middle of the Frejus tunnel under 1 800 m of rock. The rock coverage suppress the cosmic ray flux by about 2 millions with respect to the surface, thus, the LSM offers an excellent site for rare-event searches which would, if located on the surface, be overwhelmed by the cosmic-ray background. As semiconductor devices continue to be scaled down, the integrated circuits are sensitive to interactions with cosmic-ray particles on the surface (primarily atmospheric neutrons) or to interactions with alpha-particles produced in on-chip radioactive impurities disintegrations. The ultra-low background environment at LSM allows the measurement of extremely low radioactivity levels. The aim of the work presented in this paper is to assess the feasibility of the alpha-emission measurement in materials commonly used in integrated circuits, by means of ultra-low level gamma-spectrometry. An epoxy slab has been measured and the surface ?-emission has been deduced from the radioactive impurities level. The result is compared to the value obtained with an a- gas proportional counter. (authors)

292

Absolute measurement of radiation losses of a tokamak in the region of ultrasoft X-radiation  

International Nuclear Information System (INIS)

In this work experiments were performed to investigate the question to which extent spectroscopic measurements in the ultrasoft X-ray region (lambda=1-10nm) are a useful technique for diagnosing the relatively cool edge region (Tsub(e)approx.=100-200 eV) of fusion-oriented plasmas. Object of these measurements was the plasma centre of a small tokamak where the plasma parameters are comparable to those in the edge region mentioned above. The measurements were done with a Bragg-spectrometer using either TAP (2d=2.59 nm) or lead stearate (2d=10.04 nm) as analyzer crystal. This allowed to cover the whole spectrum between 0.5 and 9 nm with one instrument. Using a photon-counting detector the spectrometer/detector system was absolutely calibrated by measuring the transmission of its different components by means of monochromatic X-ray radiation. For the investigated tokamak plasma intense line spectra in the region 1.4 nm =4.4 nm have been observed, where the former was caused by the high ionization stages of oxygen (OVII and OVIII), whereas the latter could be explained by Ar- to Na-like ions of the metallic impurities Fe, Cr, and Ni. (orig./HT)

293

Airborne Measurement of Radioactivity by Learjet 35 A  

International Nuclear Information System (INIS)

Full text: The Deutscher Wetterdienst (DWD, German Meteorological Service) is responsible for surveillance of radioactivity in the atmosphere. In case of an accident, radioactive plumes may be expected in high heights up to the tropopause, however it depends on the type of accident. For this reason, aircraft measurements are necessary as a supplement to ground-based measuring sites, especially in case of non available details about the source of radioactive release and lack of details about the accident. The authors present an aircraft, type Learjet 35 A, used for localising radioactive contaminated air masses up to 33,000 feet (10,000 m) and the measurement of artificial radionuclides on aerosols. For this purpose the jet is equipped with an isokinetic high-volume sampler for collection of aerosols on filters outside the pressurised cabin and an onboard gamma spectrometry system with a high purity germanium detector to analyse the interchangeable, contaminated filters during flight, as well as a dose ratemeter, a radon daughter monitor and for navigation a GPS (Global Positioning System). The collection of gaseous iodine is optional. The meteorological parameters temperature, relative humidity, wind speed and wind direction are determined as well. Resulting data are transmitted by global VHF datalink (Very High Frequency) from the plane to the DWD headquarter and used for verifying the prognosis. In case of emergency the plane has to be airborne not later than 10 houe has to be airborne not later than 10 hours after alert. Homebase of the Learjet is a German military airbase, 100 km northwest of Hamburg. Six backup Learjets are available. The Learjet's service ceiling is 41,000 feet (12,330 m), cruising speed 800 km/hr, max. flying time 5 hrs. Originally developed to be operated in Germany, the Learjet can reach every destination in Europe within 3 hours. (author)

294

Reservoir properties inversion in a karst aquifer using absolute gravity measurements  

Science.gov (United States)

Direct estimate of water storage and transfer in karst aquifers are difficult to obtain due to the extreme permeability variation of the medium. In this study, we aim to quantify water transfer properties in a karst aquifer of the Larzac plateau (South Massif Central, France) using absolute gravity monitoring. Our measurements are cutting edge as they directly measure the integrated water content below the gravimeter. We analyze monthly repeated FG5 absolute gravity measurements (1-2 microGal precision) over a three-year period at three sites on the karst aquifer. Important precipitation events lead to significant gravity increases which peak up to several weeks after the events depending on the site. Also, gravity decreases in a different manner at each site during drier periods. We consider the different gravity responses at each site to relate to water transfer properties between the surface and the unsaturated zone beneath. Within this scope, the gravity signal is used to invert for those water transfer properties. A simple two-tank reservoir model including a ‘soil' reservoir that feeds into a ‘subsurface' reservoir is used as the forward model in a Monte Carlo simulation. Reservoir discharge proceeds according to Maillet's law. Water levels within the reservoirs are converted into a gravity signal considering an infinite slab scaled by a factor that accounts for both the surrounding topographic effects and the water interception by the building where the measurements are made. Inverted parameters are the discharge constants and the scaling factors. Model input is rainfall measured with rain gauges at each site minus estimated evapotranspiration. The inversion leads to scaling factors much smaller than 1 for the attraction of the surface reservoir. The effects of the surrounding topography and those of the building on gravity are compared to the inversion result of the ‘surface reservoir' scaling factors. We discuss if the forward model and underlying assumptions may be well-suited to account for the observed signal. We finally attempt to link the gravity-based discharge properties of the ‘subsurface' reservoir with the local karstification at each site and with the whole aquifer dynamics.

Sabrina, Deville; Thomas, Jacob; Jean, Chery; Roger, Bayer; Cedric, Champollion; Moigne Nicolas, Le

2010-05-01

295

Hair radioactivity as a measure of exposure to radioisotopes  

Science.gov (United States)

Since many radioisotopes accumulate in hair, this tropism was investigated by comparing the radioactivity of shaved with plucked hair collected from rats at various time intervals up to 24 hrs after intravenous injection of the ecologically important radioisotopes, iodine-131, manganese-54, strontium-85, and zinc-65. The plucked hair includes the hair follicles where biochemical transformations are taking place. The data indicate a slight surge of each radioisotpe into the hair immediately after injection, a variation of content of each radionuclide in the hair, and a greater accumulation of radioactivity in plucked than in shaved hair. These results have application not only to hair as a measure of exposure to radioisotopes, but also to tissue damage and repair at the hair follicle.

Strain, W. H.; Pories, W. J.; Fratianne, R. B.; Flynn, A.

1972-01-01

296

Measurement of environmental radioactivity in Taegu area: pt. 8  

International Nuclear Information System (INIS)

Since July 1956, the survey of environmental radioactivity has continuously been carried out as a fall-out program. This report concerns radioactivity in Air-borne dust. Fall-out, and Rain-out measured in Taegu area (N.lat. 35sup(0)53', E.long. 128sup(0)37') during the period of 2 years from January 1, 1977 to December 31, 1978. This report includes special survey results from the 22th, 23th, and 24th nuclear explosion tests carried out in the Lop Nor (N.lat. 40sup(0), E.long. 90sup(0)), China. The results of these measurements are as follows; The annual average values of radioactivity of the Air-borne dust collected by the air sample in this period were (2.95+-0.02)p?Ci/cc(6 hr.), and (0.08+-0.01)p?Ci/cc(12hr.). The maximum radioactivities in this period of investigation were (19.61+-0.58)p?Ci/cc(6 hr.:Feb. 11,'77), and (0.52+-0.20)p?Ci/cc (120hr. Jun. 13,'77). The annual average values of radioactivity of the Fall-out collected by gummed papers in this period were (0.23+-0.02) mCi/km2-10d. (6hr.), and (0.13+-0.02) mCi/km2-10d. (120hr.). While the maxium values of radioactivities during the period were (2.31+-0.21) mCi/km2-10d. (6hr.: Oct. 1 11, '77), and (1.63+-0.20) mCi/kmsup(2)-10d. (120hr. : Oct. 1 11, '77). The annual average value of radioactivities in the Rain-out collected at fixed time daily were (0.84+-0.19)x10sup(-8)?Ci/cc (6hr.), and (0.58+-0.12)x10sup(-8)?Ci/cc(120hr.), an8+-0.12)x10sup(-8)?Ci/cc(120hr.), and the maximum values of the radioactivities during the period were (8.93+-1.02)x10sup(-8)?Ci/cc (6hr.:6approximately7,'77), and (7.55+-1.00)x10sup(-8)?Ci/cc(120hr.: Oct. 6approximately7,'77). The results of the environmental radioactivities caused by these three time-nuclear explosion tests (22th, 23th, and 24th) were much smaller than those of the former tests (1st through 21st). According to the above data obtained, we have found that the maximum permissible concentrations(M.P.C.approximately10sup(-7)?Ci/cc for water, 4x10sup(-13)?Ci/cc for air) are not reached both in water and in air. (Author)

297

Radioactivity measurements of 32P solutions by calorimetric methods  

International Nuclear Information System (INIS)

Radioactivity of 32P solution is measured with a twin-cup heat-flow microcalorimeter. In order to convert whole decay energy evolved from the 32P solution in a glass vial into thermal power, 5 mm-thick lead container was used as a radiation absorber. Corrections for heat loss due to thermal radiation and bremsstrahlung escape as well as an effect of impurity (33P) are conducted. The overall uncertainty of the nondestructive measurement as a sample is in a container is estimated to be ± 1.5 %. Discussion about estimates of uncertainties is also given in detail. (author)

298

Fundamental studies on the direct measurement of airborne radioactive dust  

International Nuclear Information System (INIS)

Basic experiments were performed to develop the apparatus with which we can measure the radioactive density of air borne dust directly during flight. Characteristics of sample collecting filters and the plastic scintillators as a radiation detector were investigated by airplanes. From the experimental results the detectable minimum has been estimated to be about 100 PCi/m3 assuming that the detectable limit is four times as much as the standard deviation of the background of the detector. This result shows that the direct measurement apparatus is useful for the monitor of the extraordinary situation, such as a nuclear explosion test, though the sensitivity is not sufficient for use in ordinary circumstances. (auth.)

299

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

300

Validation of SCIAMACHY level-1 radiance products by using absolutely calibrated DOAS-measurements  

Science.gov (United States)

SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric CHarto-graphY) onboard of ENVISAT, which was launched successfully at February 28th 2002, signify with his broad banded measurement wavelength region (240 nm - 2380 nm) a huge advance in atmospheric monitoring. Within the scope of ongoing validation of the SCIAMACHY data products there are also several measurement campaigns taking place using the DOAS (Differential Op-tical Absorption Spectroscopy) technique in diverse viewing geometries and locations like ground-based, airborne (AMAX-DOAS) etc. The novel approach of calibrating these DOAS-devices absolutely offers in addition the opportunity to validate SCIAMACHY level-1 radiance products. The talk will describe this radiometric calibration procedure of ground-based- and AMAX-DOAS and present first validation results of SCIAMACHY- and, additionally for comparison, GOME-radiance products in the wavelength region 320-410 nm (ground-based) resp. 300-570 nm (AMAX). To compare the DOAS- and satellite-measurements made under different viewing geometries an appropriately adapted radiative transfer modelling scenario using SCIATRAN/CDI under clear, cloud-free sky conditions is applied.

Krause, H.; Gurlit, W.; Gerilowski, K.; Burrows, J. P.

2003-04-01

301

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

302

Direct and absolute absorption measurements in optical materials and coatings by laser induced deflection (LID) technique  

Science.gov (United States)

Different strategies of the laser induced deflection (LID) technique for direct and absolute absorption measurements are presented. Besides selected strategies for bulk and coating absorption measurements, respectively, a new strategy is introduced allowing the transfer of the LID technique to very small samples and to significantly increase the sensitivity for materials with a very weak photo-thermal response. Additionally, an emphasis is placed on the importance of the calibration procedure. The electrical calibration of the LID setup is compared to two other approaches that use either doped samples or highly absorptive reference samples in combination with numerical simulations. Applying the LID technique, we report on the characterization of AR coated LBO crystals used in high power NIR/VIS laser applications. The comparison of different LBO crystals shows that there are significant differences in both, the AR coating and the LBO bulk absorption. These differences are much larger at 515 nm than at 1030 nm. Absorption spectroscopy measurements combining LID technique with a high power OPO laser system indicate that the coating process affects the LBO bulk absorption properties. Furthermore, the change of the absorption upon 1030 nm laser irradiation of a Nd:YVO4 laser crystal is investigated and compared to recent results. Finally, Ytterbium doped silica raw materials for high power fiber lasers are characterized with respect to the absorption induced attenuation at 1550 nm in order to compare these data with the total attenuation obtained for the subsequently manufactured laser active fibers.

Mühlig, Ch.

2012-01-01

303

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

Energy Technology Data Exchange (ETDEWEB)

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{sup +}e{sup ?} 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=10{sup 33}s{sup ?1}cm{sup ?2} value. Two ways extending the method to the large pile-up periods corresponding to higher instantaneous luminosities are proposed.

Krasny, M.W., E-mail: krasny@lpnhep.in2p3.fr [LPNHE, Pierre and Marie Curie University, CNRS-IN2P3, Tour 33, RdC, 4, pl. Jussieu, 75005 Paris (France); Chwastowski, J. [Institute of Teleinformatics, Faculty of Physics, Mathematics and Computer Science, Cracow University of Technology, ul. Warszawska 24, 31-115 Kraków (Poland); Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland); Cyz, A.; S?owikowski, K. [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland)

2013-11-21

304

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

305

Particle sizing of airborne radioactivity field measurements at Olympic Dam  

International Nuclear Information System (INIS)

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

306

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

307

Absolute measurements of optical oscillator strengths of noble-gas resonance lines  

International Nuclear Information System (INIS)

We have remeasured the optical oscillator strengths of eight noble-gas resonance lines in the vacuum-ultraviolet region. The measurements use a 900-eV collimated electron beam to excite the atoms, and the transmission of the emitted radiation is measured as a function of the gas density. In the method of self-absorption used here, the measured oscillator strengths are proportional to the distance between the electron beam and the fixed aperture of the spectrometer-detector system. We investigated and eliminated a possible systematic effect in the determination of the absorption length due to deflections of the electron beam. These measurements are performed at higher energies than our previous experiments at 100 eV in order to keep the electron-beam path better defined and aligned with the electron-gun apertures. The measured absolute oscillator strengths are He I (58.4 nm), 0.2700±0.0076 (2.8%); He I (53.7 nm), 0.0737±0.0023 (3.1%); Ne I (74.4 nm), 0.010 95±0.000 32 (2.9%); Ne I (73.6 nm), 0.1432±0.0038 (2.6%); Ar I (106.7 nm), 0.0580±0.0017 (2.9%); Ar I (104.8 nm), 0.2214±0.0068 (3.1%); Kr I (123.6 nm), 0.1775±0.0050 (2.8%); and Kr I (116.5 nm), 0.1416±0.0041 (2.9%)

308

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)

309

Absolute-scale measurement of compton backscattering in germanium at 105.3 keV  

International Nuclear Information System (INIS)

The differential cross section d2?/dE d? was measured at an incident photon energy of 105.3 keV in germanium on absolute scale. The measurements were made using two high purity Ge detectors that operated in a coincidence mode. One detector served as the target and detector of ejected electrons, and another as the detector of Compton-scattered photons. It was found that fast (multiple) cascades have little influence on the data of the 105.3 keV crossover transition. An improved determination of the detector efficiency was made. The calculated values of the cross-section d2?/dE d? using the impulse approximation (IA) with Hartree-Fock (HF) wave functions are in excellent agreement with the experimental cross-sections, while the IA with hydrogen like (HL) wave functions give fair agreement. A comparison of the calculated values of the cross-sections obtained with HF and HL wave functions for each subshell in germanium gives new values for effective charges, which improve agreement between the results of IA with HL and experimental values. (author)

310

In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope  

Science.gov (United States)

The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron- plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between approx. 6 and approx. 13 GeV with an estimated uncertainty of approx. 2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Barbielini, G; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B,; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Gehrels, N.; Hays, E.; McEnery, J. E.; Thompson, D. J.; Troja, E. J.

2012-01-01

311

Measurement of the Absolute Branching Fractions for $D^-_s\\!\\rightarrow\\!\\ell^-\\bar{\  

Energy Technology Data Exchange (ETDEWEB)

The absolute branching fractions for the decays D{sub s}{sup -} {yields} {ell}{sup -}{bar {nu}}{sub {ell}} ({ell} = e, {mu}, or {tau}) are measured using a data sample corresponding to an integrated luminosity of 521 fb{sup -1} collected at center of mass energies near 10.58 GeV with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. The number of D{sub s}{sup -} mesons is determined by reconstructing the recoiling system DKX{gamma} in events of the type e{sup +}e{sup -}DKXD*{sub s}{sup -}, where D*{sub s}{sup -} {yields} D{sub s}{sup -}{gamma} and X represents additional pions from fragmentation. The D{sub s}{sup -} {yields} {ell}{sup 0}{nu}{sub {ell}} events are detected by full or partial reconstruction of the recoiling system DKX{gamma}{ell}. The branching fraction measurements are combined to determine the D{sub s}{sup -} decay constant f{sub D{sub s}} = (258.6 {+-} 6.4 {+-} 7.5) MeV, where the first uncertainty is statistical and the second is systematic.

del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, David Nathan; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U.; /more authors..

2010-10-27

312

In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope  

International Nuclear Information System (INIS)

The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron-plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between ?6 and ?13 GeV with an estimated uncertainty of ?2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

313

ArtDeco: a beam-deconvolution code for absolute cosmic microwave background measurements  

Science.gov (United States)

We present a method for beam-deconvolving 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 aTlm, aElm, and aBlm coefficients of the observed sky. From these one can derive 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 tested the code with extensive simulations, mimicking the resolution and data volume of Planck 30 GHz and 70 GHz channels, but with exaggerated beam asymmetry. We applied it to multipoles up to l = 1700 and examined the results in both pixel space and harmonic space. We also tested the method in presence of white noise. The code is released under the terms of the GNU General Public License and can be obtained from http://sourceforge.net/projects/art-deco/

Keihänen, E.; Reinecke, M.

2012-12-01

314

SQUID-based setup for the absolute measurement of the Earth’s magnetic field  

International Nuclear Information System (INIS)

We present a configuration of LTS dc SQUID magnetometers that is suited for an absolute measurement of the vector components of the Earth’s magnetic field with a white noise level of about 6 fT Hz?1/2. Due to its periodic voltage–flux characteristic, a SQUID’s output voltage generally corresponds to a set of equidistant fluxes or magnetic field strengths. To resolve this ambiguity, we introduce a configuration of coplanar SQUIDs integrated on a single chip, which exhibit effective areas differing by several orders of magnitude. The set of possible magnetic field strengths matching the output voltages of these SQUIDs is thereby significantly reduced and especially unique for magnetic field strengths less than a certain threshold value of about 10 ?T in our current implementation. The SQUIDs are realized with 0.8 ?m cross-type Josephson junctions that withstand high background fields of up to 3.9 mT during cool down and operation. A first one-dimensional experimental implementation successfully measured the modulation of the magnetic field component perpendicular to the sensor surface with amplitudes exceeding 50 ?T. The overall dynamic range of the SQUID magnetometer system achieves 190 dB. (paper)

315

In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope  

CERN Document Server

The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron-plus-positron (CRE) spectrum in low earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between ~6 and ~13 GeV with an estimated uncertainty of ~2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pul...

,

2011-01-01

316

Radioecological observations in the trace-measurement and dosimetric evaluation of radioactive traces in the air  

International Nuclear Information System (INIS)

The following topics are dealt with: Weekly measurement of 137Cs and 40K, long-time measurement series, natural radioactive nuclides, artificial radioactive nuclides, 85Kr, 133Xe, 90Sr, 137Cs, and 238-240Pu, the radioecology of 129I, dosimetric evaluation of radioactive traces in air. (HSI)

317

Measurements and Monte Carlo calculations to determine the absolute detector response of radiochromic film for brachytherapy dosimetry  

International Nuclear Information System (INIS)

GafChromic (MD-55-2) radiochromic film has become increasingly popular for medical applications and has proven to be useful for brachytherapy dosimetry. To measure the absolute dose near a brachytherapy source, the response of the proposed detector in the measurement conditions relative to the response of the detector in calibration conditions must be known. MD-55-2 radiochromic film has been exposed in four different photon beams, a 30 and 40 kVp tungsten anode x-ray beam, a 75 kVp orthovoltage therapy beam, and a 60Co teletherapy beam to measure the relative detector response. These measurements were combined with coupled photon/electron Monte Carlo transport calculations to determine the absolute detector response. The Los Alamos National Laboratory Monte Carlo transport code MCNP4B2 was used. The measured relative response of this batch of MD-55-2 film varies from 8.79 mOD/Gy, measured for the 60Co beam, by as much as 42% for the low-energy x-ray beams. However, the absolute detector response varies from 4.32 mOD/Gy for the 60Co beam by, at most, only 6.3%. In this work we demonstrate that the absolute detector response of MD-55-2 radiochromic film is a constant and independent of beam quality. Further, this work shows that MCNP4B2 accurately simulates the energy response and geometry artifacts of the radiochromic film

318

Absolute frequency measurement for the emission transitions of molecular iodine in the 982 - 985 nm range  

International Nuclear Information System (INIS)

We report high-precision frequency measurements of the separate hyperfine structure (HFS) components of the emission B - X system transitions of 127I2 molecules in the 982 - 985 nm range. To resolve the HFS of the emission lines, advantage was taken of the method of three-level laser spectroscopy. The function of exciting radiation was fulfilled by the second harmonic of a cw Nd : YAG laser, and the probe radiation in the 968 - 998 nm range was generated by an external-cavity diode laser. The output Nd : YAG laser frequency was locked to an HFS component of the absorption transition and the probing laser radiation to the emission transition component. When both frequencies were locked to HFS components with a common upper level, the output diode laser frequency was precisely equal to the emission transition frequency. The output frequency of the thus stabilised diode laser was measured with the help of a femtosecond optical frequency synthesiser based on a Ti : sapphire laser. We present the results of the absolute frequency measurements of 20 HFS components belonging to six vibrational - rotational transitions of the B - X system of iodine [R56(32 - 48)a1, P58(32 - 48)a1, P85(33 - 48)a1, R87(33 - 48a1, R88(33 - 48)a10] and all 15 components of the R86(33 - 48) line. The relative measurement uncertainty is equal to 7×10-10 and is determined by the frequency instability of the diode laser radiation.ion.

319

Absolute frequency measurement for the emission transitions of molecular iodine in the 982 - 985 nm range  

Energy Technology Data Exchange (ETDEWEB)

We report high-precision frequency measurements of the separate hyperfine structure (HFS) components of the emission B - X system transitions of {sup 127}I{sub 2} molecules in the 982 - 985 nm range. To resolve the HFS of the emission lines, advantage was taken of the method of three-level laser spectroscopy. The function of exciting radiation was fulfilled by the second harmonic of a cw Nd : YAG laser, and the probe radiation in the 968 - 998 nm range was generated by an external-cavity diode laser. The output Nd : YAG laser frequency was locked to an HFS component of the absorption transition and the probing laser radiation to the emission transition component. When both frequencies were locked to HFS components with a common upper level, the output diode laser frequency was precisely equal to the emission transition frequency. The output frequency of the thus stabilised diode laser was measured with the help of a femtosecond optical frequency synthesiser based on a Ti : sapphire laser. We present the results of the absolute frequency measurements of 20 HFS components belonging to six vibrational - rotational transitions of the B - X system of iodine [R56(32 - 48)a1, P58(32 - 48)a1, P85(33 - 48)a1, R87(33 - 48a1, R88(33 - 48)a10] and all 15 components of the R86(33 - 48) line. The relative measurement uncertainty is equal to 7 Multiplication-Sign 10{sup -10} and is determined by the frequency instability of the diode laser radiation.

Matyugin, Yu A; Ignatovich, S M; Kuznetsov, Sergei A; Nesterenko, M I; Okhapkin, M V; Pivtsov, V S; Skvortsov, Mikhail N; Bagaev, Sergei N [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

2012-03-31

320

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.)

321

Precision Measurement of Pion-Proton Absolute Differential Cross Sections at Energies Spanning the Delta Resonance.  

Science.gov (United States)

A measurement of the absolute differential cross section in the pi^+/-p elastic reaction for incident pion laboratory kinetic energies of T_pi = 141.2, 168.8, 193.2, 218.1, 240.9, and 267.3 MeV is described. Measurements where the scattered pion and recoil proton were detected in coincidence with the incident pion beam were taken at all energies. These measurements obtained data at six laboratory pion angles from 60^circ to 155^circ. Single arm measurements, where only the scattered pions were detected at six near-forward angles from 20^circ to 70^circ, were performed at the lowest four energies. Both the single arm and coincidence measurements employed a flat-walled supercooled liquid hydrogen target. The uncertainty in the proton density of this target was 0.5%. Solid CH_2 targets were also employed for coincidence measurements at the lowest four energies. The proton density uncertainties of these targets was 1%. Numerous measurements were performed to test the reproducibility of the cross sections under a variety of experimental conditions, and to elucidate potential sources of systematic uncertainty. Excellent consistency was found amongst all these data sets. In particular, the results obtained with the LH_2 and CH_2 targets were consistent at all energies. The final pi^+p data have typically 1-1.5% statistical and 1% normalization uncertainties, whereas these uncertainties are typically 1.5-2% and 1.5%, respectively, for the pi ^-p data. At incident pion energies above 190 MeV, there is reasonable agreement between the results from these measurements and those of Bussey et al. The agreement with the data of Sadler et al. at 263 MeV is excellent. Below 190 MeV, the data presented here are systematically below the data of Bussey et al., well outside the stated normalization uncertainties. The data are consistent within the stated uncertainties with the Brack et al. results near 140 MeV, although the latter results are systematically a few percent lower. At all energies and angles, the results from this work are in agreement within one standard deviation with the prediction of the Virginia Polytechnic Institute SP95 partial wave analysis (PWA) solution, although the data were not included in the analysis. Consequently, the work presented here adds support to this PWA which concludes that the pion nucleon coupling constant {g ^2over4pi} = 13.7, and that the mass of the Delta resonance is 1233.7 MeV, in disagreement with earlier results of partial wave analyses from other groups.

Pavan, Marcello Maurizio

1995-01-01

322

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

323

Direct measurements of neutron capture on radioactive isotopes  

CERN Document Server

We simulated the response of a 4p calorimetric g-detector array to decays of radioactive isotopes on the s-process path. The GEANT 3.21 simulation package was used. The main table contains estimates on the maximum sample size and required neutron flux based on the latest available neutron capture cross section at 30 keV. The results are intended to be used to estimate the feasibility of neutron capture measurements with 4p arrays using the time of flight technique.

Couture, A

2009-01-01

324

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.)

325

Radioactive ion implantation as a tool for wear measurements  

International Nuclear Information System (INIS)

The present paper deals with ion implantation of radioactive krypton ions in surfaces with aim of measuring wear of different magnetic materials in sound-heads. The technique is especially suited for a relatively fast comparison of wear-characteristics of materials of varying composition in small inaccessible areas. In the present case utilisation of a 60 KeV accelerator allows determination of a total wear as small as 0.05 ?m with an accuracy of 10%. Further the technique yields information of the time dependence of the wear process with an accuracy less than 0.001 ?m. (author)

326

The measurement of the radioactive aerosol diameter by position sensitive semiconductor detectors, 1  

International Nuclear Information System (INIS)

The measurement of the diameter of radioactive aerosol, in particular plutonium aerosol, is very important for the internal dose estimation. Determination of the diameter of radioactive aerosol is performed by using position sensitive semiconductor detector (PSD). The filter paper with the radioactive aerosols is contacted to the PSD which is connected to the data processor so that the diameter of the aerosol is calculated from the measured radioactivity. This investigation was performed in cooperation with Rikkyo University. (author)

327

Absolute HCO concentration measurements in methane/air flame using intracavity laser spectroscopy  

Science.gov (United States)

Intracavity laser absorption spectroscopy was used to measure the absorption spectra of a premixed, flat methane/air flame at a total pressure of 30 Torr. The spectra were measured in the spectral range of 16 000-16 300 cm-1. A flat flame burner was placed inside the cavity of a broadband dye laser pumped by a cw argon-ion laser. The spectrum of the laser output was measured by a high resolution spectrograph (with a spectral resolution of 0.003 nm). The spectrum of HCO radicals (Ã 2A''?X˜ 2A transition) was measured with a high signal-to-noise ratio at different positions above the burner, providing the first quantitative measurement of the absolute concentrations of the HCO radical in flames. The linewidths of the individual rotational lines in the spectrum can be closely fitted by the equation ?=X+ZN2(N+1)2, where X=0.37±0.03 cm-1 and Z=(8±0.5)10-6. The rotational temperature of the HCO radicals was evaluated from the spectra, but the error and the data scatter are relatively high since the lines with a high rotational quantum number N are strongly superimposed with lines from different branches. The "hot band," which can be assigned to the transition (0,0,1)-(0,9,1), was observed in spectra measured at high temperature. The value ?3?=1859 cm-1 is evaluated from the position of this "hot band." The concentration profile of the HCO radical has a maximum value of about 1.2×1013molecules/cm3 which is in reasonable agreement with computer simulation results, when the uncertainties of the absorption cross section and of the rate constants for HCO reactions are taken into account. The relatively strong lines of the CH2 radical spectrum (the b˜ 1B1?ã 1A1 transition) were also recorded in the studied wavelength range. The spectra of these two radicals can be measured simultaneously which is advantageous in combustion diagnostics.

Lozovsky, Vladimir A.; Cheskis, Sergey; Kachanov, Alexander; Stoeckel, Frédréic

1997-05-01

328

Frequency comparisons and absolute frequency measurements of 171Yb+ single-ion optical frequency standards  

CERN Document Server

We describe experiments with an optical frequency standard based on a laser cooled $^{171}$Yb$^+$ ion confined in a radiofrequency Paul trap. The electric-quadrupole transition from the $^2S_{1/2}(F=0)$ ground state to the $^2D_{3/2}(F=2)$ state at the wavelength of 436 nm is used as the reference transition. In order to compare two $^{171}$Yb$^+$ standards, separate frequency servo systems are employed to stabilize two probe laser frequencies to the reference transition line centers of two independently stored ions. The experimental results indicate a relative instability (Allan standard deviation) of the optical frequency difference between the two systems of $\\sigma_y(1000 {\\rm s})=5\\cdot 10^{-16}$ only, so that shifts in the sub-hertz range can be resolved. Shifts of several hertz are observed if a stationary electric field gradient is superimposed on the radiofrequency trap field. The absolute optical transition frequency of Yb$^+$ at 688 THz was measured with a cesium atomic clock at two times separated...

Peik, E; Schnatz, H; Schneider, T; Tamm, C; Karshenboim, S G; Tamm, Chr.

2005-01-01

329

Comparison of absolute spectral irradiance responsivity measurement techniques using wavelength-tunable lasers  

Science.gov (United States)

Independent methods for measuring the absolute spectral irradiance responsivity of detectors have been compared between the calibration facilities at two national metrology institutes, the Helsinki University of Technology (TKK), Finland, and the National Institute of Standards and Technology (NIST). The emphasis is on the comparison of two different techniques for generating a uniform irradiance at a reference plane using wavelength-tunable lasers. At TKK's Laser Scanning Facility (LSF) the irradiance is generated by raster scanning a single collimated laser beam, while at the NIST facility for Spectral Irradiance and Radiance Responsivity Calibrations with Uniform Sources (SIRCUS), lasers are introduced into integrating spheres to generate a uniform irradiance at a reference plane. The laser-based irradiance responsivity results are compared to a traditional lamp-monochromator-based irradiance responsivity calibration obtained at the NIST Spectral Comparator Facility (SCF). A narrowband filter radiometer with a 24 nm bandwidth and an effective band-center wavelength of 801 nm was used as the artifact. The results of the comparison between the different facilities, reported for the first time in the near-infrared wavelength range, demonstrate agreement at the uncertainty level of less than 0.1%. This result has significant implications in radiation thermometry and in photometry as well as in radiometry.

Ahtee, Ville; Brown, Steven W.; Larason, Thomas C.; Lykke, Keith R.; Ikonen, Erkki; Noorma, Mart

2007-07-01

330

Comparison of absolute spectral irradiance responsivity measurement techniques using wavelength-tunable lasers  

International Nuclear Information System (INIS)

Independent methods for measuring the absolute spectral irradiance responsivity of detectors have been compared between the calibration facilities at two national metrology institutes, the Helsinki University of Technology (TKK), Finland, and the National Institute of Standards and Technology (NIST). The emphasis is on the comparison of two different techniques for generating a uniform irradiance at a reference plane using wavelength-tunable lasers. At TKK's Laser Scanning Facility (LSF) the irradiance is generated by raster scanning a single collimated laser beam, while at the NIST facility for Spectral Irradiance and Radiance Responsivity Calibrations with Uniform Sources (SIRCUS), lasers are introduced into integrating spheres to generate a uniform irradiance at a reference plane. The laser-based irradiance responsivity results are compared to a traditional lamp-monochromator-based irradiance responsivity calibration obtained at the NIST Spectral Comparator Facility (SCF). A narrowband filter radiometer with a24 nm bandwidth and an effective band-center wavelength of 801 nm was used as the artifact. The results of the comparison between the different facilities, reported for the first time in the near-infrared wavelength range, demonstrate agreement at the uncertainty level of less than 0.1%. This result has significant implications in radiation thermometry and in photometry as well as in radiometry

331

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.

332

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 al 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 correction. 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)(v/v(sub o)(exp -2.599+/-0.036 from 22 MHz to 10 GHz (v(sub 0) = 310 MHz) in addition to a CMB temperature of 2.725 +/- 0.001 K.

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

2011-01-01

333

Average value of available measurements of the absolute air-fluorescence yield  

CERN Document Server

The air-fluorescence yield is a key parameter for determining the energy scale of ultra-high-energy cosmic rays detected by fluorescence telescopes. A compilation of the available measurements of the absolute air-fluorescence yield normalized to its value in photons per MeV for the 337 nm band at given pressure and temperature has been recently presented in Ref. [1]. Also, in that paper, some corrections in the evaluation of the energy deposited in the corresponding experimental collision chambers have been proposed. In this note this comparison is updated. In addition, a simple statistical analysis is carried out showing that our corrections favor the compatibility among the various experiments. As a result, an average value of 5.45 ph/MeV for the fluorescence yield of the 337 nm band (20.1 ph/MeV for the spectral interval 300-420 nm) at 1013 hPa and 293 K with an uncertainty of 5% is found. This result is fully compatible with that recently presented by the AIRFLY collaboration (still preliminary) in such a...

Rosado, J; Arqueros, F

2011-01-01

334

Radioactivity measurements in the vicinity of Swiss nuclear power plants  

International Nuclear Information System (INIS)

To determine the radionuclide concentration in soil and on soil surface, respectively, caused by radionuclide releases from nuclear power plants, field gamma spectrometry is used to obtain, in a short period of time, quantitative data about the environmental radiation field, natural or man-made. This is obviously difficult to achieve by conventional sampling methods and laboratory analysis. This word describes the instruments used and the calibration methods, and gives the results of in situ measurements made around the Swiss nuclear power plants. The measurements and computations are compared with a laboratory analysis of collected soil samples and with total exposure rate measurements in air. In addition to natural radioactivity this method allows especially the detection of radionuclides released from nuclear power stations to the environment with a good sensitivity. (orig.)

335

Radioactive waste reality as revealed by neutron measurements  

International Nuclear Information System (INIS)

To comprehend certain aspects of the contents of a radioactive waste container is not a trivial matter, especially if one is not allowed to open the container and peer inside. One of the suite of tools available to a practioner in the art of nondestructive assay is based upon neutron measurements. Neutrons, both naturally occuring and induced, are penertrating radiations that can be detected external to the waste container. The practioner should be skilled in applying the proper technique(s) to selected waste types. Available techniques include active and passive neutron measurements, each with their own strengths and weaknesses. The waste material itself can compromise the assay results by occluding a portion of the mass of fissile material present, or by multiplying the number of neutrons produced by a spontaneously fissioning mass. This paper will discuss the difficult, but albeit necessary marriage, between radiioactive waste types and alternative neutron measurement techniques

336

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

337

Standardisation of 125Sb and 154Eu, and measurement of absolute gamma-ray emission probabilities  

International Nuclear Information System (INIS)

A method has been devised to separate 125Sb from its short-lived daughter 125mTe. This technique was based on the repeated use of columns of anion exchange resin and supplemented by chemical procedures chosen to avoid any steps involving evaporation, which in initial trials gave severe problems due to the volatility of the antimony. Standardisation by 4??-? coincidence counting was carried out within a few days of the separation, allowing for the daughter which grows in at about 0.25% per day. Beta counting efficiencies, as measured by the ratio of coincidence to gamma count rates, of up to 90% and 95% respectively were obtained for the two gamma-ray energy windows used. The ingrowth was monitored over a period of one month by gamma-ray spectrometry, using the weak 109 keV gamma-ray of 125mTe, to check the original separation. Samples of 154Eu were produced by neutron irradiation of high purity 153Eu, which was obtained by passing inactive europium through the NPL isotope separator. A solution of the 154Eu was standardised by coincidence counting, again using two gamma-ray energy windows, to give efficiencies of 96% and 98%. Absolute gamma-ray emission probabilities were measured for both nuclides using a germanium spectrometer calibrated with a range of nuclides of known activities and gamma-ray emissions. Sources were positioned 55 cm from the detector to ensure that real summing effects were neglire that real summing effects were negligible. (orig.)

338

Radioactivity measurements in ceramics industries: results and comments  

International Nuclear Information System (INIS)

As part of the NORM evaluation programme launched by the Spanish Nuclear Safety Council, a radiological study of the ceramics industry was carried out by the Environmental Radioactivity Laboratory of the Universidad Politecnica de Valencia. The study covered three types of plant: zircon sand milling, ceramic frit production and ceramic tile production, all of which use zircon as a raw material. In accordance with European Directive 96/29/Euratom, these types of plant are of radiological interest because of the presence of 238U and to a lesser extent 232Th, together with their progeny. The first step in the study was to collect information on materials and processes used in the different types of factory, after which a radiological characterization of the materials, including dust from the indoor environment, was performed. Gamma spectrometry analysis was carried out using a Ge(HP) detector. The second step was to identify the areas in which radioactive materials and workers were present. Direct measurements were carried out in different factory areas, which were radiologically characterized using a portable radiation monitor and thermoluminescent dosimeters. Finally, the external and internal radiation doses received by workers were estimated, on the basis of the aforementioned measurements. (author)

339

Some triple-filament lead isotope ratio measurements and an absolute growth curve for single-stage leads  

Science.gov (United States)

Triple-filament analyses of three standard lead samples are used to calibrate a mass spectrometer in an absolute sense. The bias we measure is 0.0155 percent per mass unit, and the precision (for 95% confidence limits) is ??0.13% or less for all ratios relative to 204Pb. Although its precision is not quite so good as that of the lead-tetramethyl method in the analysis of large samples, the triple-filament method is less complex and is an attractive alternative for smaller sample sizes down to 500 ??g. Triple-filament data are presented for six possibly single-stage lead ores and one feldspar. These new data for ores are combined with corrected tetramethyl data for stratiform lead deposits to compute absolute parameters for a universal single-stage lead isotope growth curve. Absolute isotopic ratios for primeval lead have been determined by Oversby and because all the previous data for both meteorites and lead ores were similarly fractionated, the absolute value of 238U 204Pb = 9.09 ?? 0.06 for stratiform leads is little different from the value 8.99 ?? 0.05 originally computed by Ostic, Russell and Stanton. Absolute values for lead isotope ratios for all interlaboratory standard samples presently available from the literature are tabulated. ?? 1969.

Stacey, J.S.; Delevaux, M.E.; Ulrych, T.J.

1969-01-01

340

Natural radioactivity measurements of building materials in Baotou, China  

International Nuclear Information System (INIS)

Natural radioactivity due to 226Ra, 232Th and 40K in the common building materials collected from Baotou city of Inner Mongolia, China was measured using gamma-ray spectrometry. The radiation hazard of the studied building materials was estimated by the radium equivalent activity (Raeq), internal hazard index (Hin) and annual effective dose (AED). The concentrations of the natural radionuclides and Raeq in the studied samples were compared with the corresponding results of other countries. The Raeq values of the building materials are below the internationally accepted values (370 Bq kg-1). The values of Hin in all studied building materials are less than unity. The AEDs of all measured building materials are at an acceptable level. (authors)

341

Natural radioactivity measurements of building materials in Baotou, China.  

Science.gov (United States)

Natural radioactivity due to (226)Ra, (232)Th and (40)K in the common building materials collected from Baotou city of Inner Mongolia, China was measured using gamma-ray spectrometry. The radiation hazard of the studied building materials was estimated by the radium equivalent activity (Ra(eq)), internal hazard index (H(in)) and annual effective dose (AED). The concentrations of the natural radionuclides and Ra(eq) in the studied samples were compared with the corresponding results of other countries. The Ra(eq) values of the building materials are below the internationally accepted values (370 Bq kg(-1)). The values of H(in) in all studied building materials are less than unity. The AEDs of all measured building materials are at an acceptable level. PMID:22522177

Zhao, Caifeng; Lu, Xinwei; Li, Nan; Yang, Guang

2012-12-01

342

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)

343

Quality assurance of radioactivity measurements for soil samples in the investigation of national environmental natural radioactivity level  

International Nuclear Information System (INIS)

The author summarizes the work of quality assurance of radioactivity measurements for soil samples in the investigation of national environmental natural radioactivity level. Examination of analytical methods of soil sample and inspection survey of analytical results for 29 provinces, municipalities, autonomy regions and cities of Wuhan and Baotou were introduced. The results of examination and inspection survey were given, and some technique problems involved were also discussed

344

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)

345

Measurement of the relative 235U concentration and the absolute 235U content of individual HTGR fuel particles  

International Nuclear Information System (INIS)

The absolute 235U content and the relative 235U concentration of 77 individual TRISO-coated HTGR fuel particles were measured using delayed-neutron activation analysis. The particles were from batches A611 and A601. The measurements, which were done to determine the variation in kernel 235U concentration with kernel diameter, revealed no significant size-dependent variation in the kernel uranium concentration. The absolute measurement technique and its applicability to the construction of assay machine calibration standards are discussed. With the present irradiation facility, the technique was found to be too time consuming to be used to measure the large number of particles needed for a calibration standard individually

346

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)

347

Monitoring the 2008 Northern Cascadia ETS Episode With Absolute Gravity Measurements  

Science.gov (United States)

The monitoring of subduction zone Episodic Tremor and Slip (ETS) has been carried out primarily using seismic data for tremor and continuous GPS observations for transient slip. More recently, the establishment of the Plate Boundary Observatory has added borehole instrumentation consisting of Gladwin borehole strainmeters (BSM) as well as pore pressure gauges. For sites on southern Vancouver Island, the regularity of ETS episodes has allowed us to schedule extended periods of continuous absolute gravity (AG) measurements to augment these other data and thereby help in understanding the fundamental physical processes involved in the generation of ETS. For the 2008 ETS event in the northern portion of the Cascadia Subduction Zone, AG observations were carried out at the Pacific Geoscience Centre (PGC), near Victoria, BC, Canada. PGC is also the site of three BSM's and a continuous GPS station whose data have been used in the past to constrain models of slip on the subduction plate interface. This contribution focuses on the analysis of the approximately 15 week-long continuous series of AG observations at PGC. Preliminary results show that a subtle transient gravity signal is observed but its origin is not clear. Little or no uplift/subsidence is observed in the GPS data although its vertical resolution is 3 or 4 mm at best. The lack of a change in elevation is not surprising since PGC lies close to the hinge-line for vertical deformation. Strainmeter data from the 3 co-located BSM's show discrepancies that indicate interfering signals of likely non-tectonic origin.

Henton, J.; Courtier, N.; Dragert, H.; Lambert, A.

2008-12-01

348

Prediction of absolute concentrations of elements from SR XRF scan measurements of natural wet sediments  

International Nuclear Information System (INIS)

We report a method to predict absolute concentrations of elements in natural wet sediments (cores) from their SR XRF scan measurements. This prediction is problematic because: (i) relationship between fluorescent intensity and element concentrations is strongly biased by variability of pore water content in thick samples; (ii) thickness and mass of fluorescent layers are likewise variable; and (iii) spectral responses are perturbed by interference of elements. It is suggested to overcome these difficulties using an adapted algorithm of fundamental parameters. The mathematical model based on this algorithm accounts for two events of photon/matter interaction. Element concentrations are estimated using reference samples and the internal standard procedure, both with correction of interference effects. The pore water content is inferred from its correlation with the Rayleigh (coherent)/Compton (incoherent) scatter intensity ratio. Sediment density is found from water content by a reliable sedimentological law. Normalization to Compton scattering accounts for the irradiated mass of wet sediment controlled by porosity and sampling-related core disturbance. The mathematical model also includes these scattering variations related to lithology, water content, and density of samples. The new method was applied to SR XRF scans of cores from Lake Baikal and Lake Teletskoye to predict concentrations of 20 elements (K-Ba, REE, Th, U). Tests against ICP-MS and conventional SR XRF (s against ICP-MS and conventional SR XRF (with traditional pretreatment of samples) show good agreement and stability of SR XRF scanning. Neglect of the disturbing effects may cause errors up to 30-150%

349

Validation of Dynamic Contrast Enhanced Ultrasound in Rodent Kidneys as an Absolute Quantitative Method for Measuring Blood Perfusion  

OpenAIRE

Contrast-enhanced ultrasound (CEUS) has demonstrated utility in the monitoring of blood flow in tissues, organs, and tumors. However, current CEUS methods typically provide only relative image-derived measurements, rather than quantitative values of blood flow in milliliters/minute per gram of tissue. In this study, CEUS derived parameters of blood flow are compared to absolute measurements of blood flow in rodent kidneys. Additionally, the effect of contrast agent infusion rate and transduce...

Kogan, Paul; Johnson, Kennita A.; Feingold, Steven; Garrett, Nicholas; Guracar, Ismayil; Arendshorst, William J.; Dayton, Paul A.

2011-01-01

350

Precise measurement of the absolute fluorescence yield of nitrogen in air. Consequences on the detection of ultra-high energy cosmic rays  

International Nuclear Information System (INIS)

The study of the energy spectrum of ultra-high energy cosmic rays (E > 1020 eV) requires to determine the energy with much more precision than what is currently achieved. The shower of particles created in the atmosphere can be detected either by sampling particle on the ground, or by detecting the fluorescence induced by the excitation of nitrogen by shower electrons. At present, the measurement of the fluorescence is the simplest and the most reliable method, since it does not call upon hadronic physics laws at extreme energies, a field still inaccessible to accelerators. The precise knowledge of the conversion factor between deposited energy and the number of fluorescence photons produced (the yield) is thus essential. Up to now, it has been determined with an accuracy of 15 % only. This main goal of this work is to measure this yield to better than 5 per cent. To do this, 1 MeV electrons from a radioactive source excite nitrogen of the air. The accuracy has been reached thanks to the implementation of a new method for the absolute calibration of the photomultipliers detecting the photons, to better than 2 per cent. The fluorescence yield, measured and normalized to 0.85 MeV, 760 mmHg and 15 Celsius degrees, is (4.23 ± 0.20) photons per meter, or (20.46 ± 0.98) photons per deposited MeV. In addition, and for the first time, the absolute fluorescence spectrum of nitrogen excited by a source has been measured with an optical grating spectrometer. (author

351

Environmental radioactivity measurements in Kastamonu region of northern Turkey.  

Science.gov (United States)

Located in the north-western part of Turkey, the province of Kastamonu has lately been receiving national attention because of its cultural and touristic attractions. This study assesses the environmental radioactivity levels of the region through measurements of indoor radon concentrations and indoor/outdoor gamma absorbed dose in air and radionuclide activities in surface soil and drinking water. The indoor (222)Rn activity concentration was found to be 98.4 Bq/m(3) equivalent to an annual effective dose of 2.48 mSv. The indoor and outdoor gamma absorbed doses were measured as 54.81 and 48.03 nGy/h, respectively, corresponding to a total gamma radiation level (of terrestrial and cosmic origin) of 0.33 mSv/y. The activity concentrations in the soil samples collected from the study area were determined as 32.93, 27.17, 431.43 Bq/kg for the natural radionuclides (238)U, (232)Th and (40)K, respectively, and 8.02 Bq/kg for the fission product (137)Cs. These natural radioactivity sources result in a terrestrial gamma level of 60 microSv/y. The water samples collected from the region carry an average of 0.0089 Bq/l of gross alpha and 0.271 Bq/l of gross beta activities which together cause an annual effective dose of 1.83 microSv. The measurement results obtained in this study indicate that the region has a background radiation level that is within the natural limits and shows no significant departure from the other parts of the country. PMID:17207627

Kam, Erol; Bozkurt, Ahmet

2007-04-01

352

Fire protection measures in a repository for radioactive wastes  

International Nuclear Information System (INIS)

For the operational phase of a repository for radioactive wastes an incident analysis has to be performed which includes possible fire events in the plant. The procedure and the fire protection measures which have to be taken are described for the planned Konrad repository where it is intended to dispose of radioactive wastes with negligible thermal influence on the surrounding rock. A fire analysis was performed for the surface and underground facilities of the repository, especially for those parts of the facility where waste packages are handled. The occurrence of fire was investigated, the thermal loads determined and the fire detection and fire fighting measures established. Examples of the realization of fire protection measures in the design of the surface facilities in order to prevent internal fire and the burning of a vehicle are given. A waste repository in a deep geological formation such as the planned Konrad repository reveals the special precautions which have to be determined, especially in the underground facility where fires are more difficult to deal with than fires in surface facilities. As a consequence of the experience gained with fire events in the underground facilities of mines, burning of a vehicle during the transport of waste packages is the only fire event which leads to release of activity from the waste packages. Within the framework of incident analysis the thermal influence on the waste packages resulting from the fire event describedes resulting from the fire event described above was determined with the aid of a load function in the form of a temperature-time function (model curve). The effects resulting from this function were calculated. (author). 4 refs, 5 figs

353

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.

354

Opportunistic mass measurements at the Holifield Radioactive Ion Beam Facility  

International Nuclear Information System (INIS)

A technique for measuring mass differences has been developed at the Holifield Radioactive Ion Beam Facility (HRIBF) that requires no specialized equipment. Mass differences are measured as position differences between known and unknown-mass isobars, dispersed at the image of the energy-analyzing magnet following the 25MV tandem post-accelerator, and identified by an energy-loss measurement. The technique has been demonstrated on neutron-rich 77-79Cu and 83-86Ge isotopes produced using the isotope separator online (ISOL) method with the 238U(p,fission) reaction, where a mass accuracy of 500 keV was achieved. These nuclides are well suited to the measurement technique, as they readily migrate out of the production target and to the ion source and comprise the most neutron-rich elements of the isobarically mixed beam. Because modest precision mass values can be obtained with only a few tens of counts of the nuclide of interest among orders of magnitude more of the isobaric neighbors closer to stability, the sensitivity of this technique makes it appropriate for initial mass measurements far from stability

355

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

356

Evaluation of representation of measuring points in atmospheric radioactivity monitoring  

International Nuclear Information System (INIS)

The radioactive concentrations of 222Rn, 220Rn, and their daughter nuclides in the air depend on geology, topography, the state of ground surface, weather, atmospheric temperature and wind velocity. Because of the dependence on these factors, it was studied that how wide area measuring points can represent, and the results are reported. It was confirmed that the basic measuring point for 222Rn concentration was able to represent the whole area in the Nagoya University by the measurement from October, 1972, to February, 1973, and the whole area in Nagoya City from October, 1976, to February, 1977. The survey area was expanded this time to the region with 30 km radius from the Nagoya University as the center, and the concentration of 222Rn daughter nuclides was obtained by filter method. This method is to count the number of 2 particles of 222Rn daughter nuclides gathered on millipore filters RA, utilizing a scintillation counter. The experimental monitoring was conducted simultaneously with the Government Industrial Research Institute Nagoya (GIRI). The temporal variation of the ratio of 222Rn daughter concentration measured at GIRI to that measured at the basic point in the Nagoya University during three months is shown. As the other observed results, the simultaneous measurements of 222Rn daughter concentration carried out at the basic point and at the location J (about 15 km south from the basic point) and the correlation between 222Rn daughter concentration measured at the basic point and that measured at the location J are presented. A criterion for classification was tried using the concentration level and the variation pattern, to clarify the representative characteristics of the locations, and the actual classification of measuring locations according to the criterion is shown. (Nakai, Y.)

357

Measuring the absolute deuterium–tritium 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 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.

358

Absolute gravity measurements in Southeast Alaska and continuous gravity observation in Juneau by ISEA2 project  

Science.gov (United States)

It is known that Southeast Alaska (SE-AK) shows a large uplift rates exceeding 32 mm/year at the maximum mainly due to the three ice changes in ages, i.e. in the Large Glacier Maximum, the Little Ice Age and the present day. Comparisons between rates of change obtained from GPS and absolute gravimeter (AG) observations and the rates predicted by model computations based on independently estimated ice mass changes indicate the existence of a very thin lithosphere (on the order of 60 km) and a low viscousity upper mantle (on the order of 1.E18 Pa s) beneath SE-AK (Larsen et al., 2005; Sato et al, 2011; Sato et al., 2012). On the other hand, it is also known that there are very large oceanic tidal loading effects in SE-AK, i.e. exceeding 2.7 cm and 8 microGals for the M2 constituent of the vertical displacement and gravity, respectively (Sato et al., 2008; Inazu et al., 2009; Sun et al., 2010; Sato et al., 2012). These regional large loading and unloading effects provide good signals to study the viscoelastic structure beneath SE-AK. A joint observation project (ISEA2) between Japan and USA groups has restarted as a five years project beginning in 2012. In June 2012, we conducted the AG measurements at the 6 sites in SE-AK at where the AG measurements were conducted by the previous ISEA1 project (Sun et al., 2010). Continuous gravity observation started also on June 2012 with a portable super conducting gravimeter (iGrav) at the EGAN library of UAS. We will introduce the results for these observations and comparisons with the previous observations and model computations. It is noted that the precipitation during the period from the winter in 2011 to the spring in 2012 was very large compared with the usual amount. We evaluate this effect on our gravity observations with a hydrological model computation (Kazama and Okubo, 2009) using the observed precipitation data as an input data. The observation with the iGrav super conducting gravimeter shall give us a useful data to evaluate the seasonal gravity changes including the hydrological effects. References: Inazu et al., 2009, J. Oceanography, Vol.65, 335-347. Kazama and Okubo, 2009, J. Geophys. Res., 114, B08402. Larsen et al., 2005, EPSL, Vol.237, 548-560. Sato et al., 2008, J. Geodyn., Vol.46, 78-89. Sato et al., 2011, Tectonophysics, Vol.511,79-88. Sato et al., 2012, J. Geophys. Res., 117, B01401. Sun et al., 2010, J. Geophys. Res., 115, B12406.

Sato, T.; Kazama, T.; Miura, S.; Ohta, Y.; Okubo, S.; Fujimoto, H.; Kaufman, M.; Herreid, S. J.; Larsen, C. F.; Freymueller, J. T.

2012-12-01

359

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

360

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.

361

Measuring and evaluation of ambient radioactivity due to mining activities  

International Nuclear Information System (INIS)

Systematic measuring, examination and evaluation of ambient radioactivity due to mining activities in the Laender Saxonia, Thuringia and Sachsen-Anhalt is placed under the responsibility of the Federal Government pursuant to paragraph 11, para. 8 German act on Preventive Radiation Protection (StrVG). The purpose of this Federal obligation is to examine the special radiological situation in these federal states which results from coal and ore mining activities, and in particular from uranium ore mining since the end of the second world war. The field and laboratory tests are exclusively performed by local firms specializing in the subject. The final evaluation of data is done by the BfS. The data are stored in the A.LAS.KA database (cadastre of long-standing pollution or contamination). (orig./DG)

362

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.)

363

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)

364

Phase-sensitive swept-source interferometry for absolute ranging with application to measurements of group refractive index and thickness.  

Science.gov (United States)

Interferometric range measurements using a wavelength-tunable source form the basis of several measurement techniques, including optical frequency domain reflectometry (OFDR), swept-source optical coherence tomography (SS-OCT), and frequency-modulated continuous wave (FMCW) lidar. We present a phase-sensitive and self-referenced approach to swept-source interferometry that yields absolute range measurements with axial precision three orders of magnitude better than the transform-limited axial resolution of the system. As an example application, we implement the proposed method for a simultaneous measurement of group refractive index and thickness of an optical glass sample. PMID:21643062

Moore, Eric D; McLeod, Robert R

2011-04-25

365

In vivo measurement of internally deposited radioactive materials  

International Nuclear Information System (INIS)

Whole-body-counter examinations are performed to measure in vivo the presence of internally deposited, photon-emitting radionuclides in people who may have, or will come in contact with radioactive substances by virtue of occupational, medical, or nonintentional exposure. For the most part, these examinations are associated with a routine monitoring program for nuclear workers to determine whether any unknown internal exposure has occurred on the job. The second most-common application of whole-body-counter examinations is associated with evaluating the internal dose, or initial intake, of workers who have unintentionally received acute exposure by virtue of an accident at the workplace. The objective of this paper is to introduce the capabilities of whole-body-counter examinations and, thereafter, emphasize how the in vivo measurement is used to evaluate internal dose. Dose assessments are performed, in part, with the aid of routine and emergency in vivo examination results to determine whether any occupational-exposure limits have been exceeded and to document the absence (or presence) of internal contamination during work exposure. Detector systems for these whole-body-counter examinations can be designed to adequately measure most intenally deposited radionuclides (with the exception of very low-energy, x-ray-emitting transuranic radionuclides)

366

Quantitative measurement of maritime sediment movement using radioactive tracers  

International Nuclear Information System (INIS)

The quantitative method described in the paper involves burying appropriate detectors over a given area of the sea bottom, the detectors being connected to recording equipment which is itself buried in the sediment or situated on the shore. Detectors arranged in this way are covered by a certain layer of radioactive sediment whose activity is proportional to its mass. Before the labelled sediments are removed, their initial activity is measured, and then, as the covering is removed, measurements are made of the gradual decrease in activity corresponding to loss of the surface layer of the bottom deposit area under investigation, expressed in g/cm2. The tracers used in the investigations discussed were natural ones such as sea with 31Si and artificial ones such as activated fragments of sodium glass (with a 6.5% admixture of Fe2O3) with 24Na . The proportional dependence of activity on mass has been confirmed for both tracers; this is an essential point for a tracer intended for quantitative measurements. This proportionality is very well maintained if a sample of highly active sediment is introduced into a large mass of inactive sediments (10-2 - 10-3). The concluding section describes the advantages of this method as a possible way of using radioisotopes with a short half-life and a low total activity of the order of a few millicuries. (author)

367

Radioactive effluent measurements at the Army Pulse Radiation Facility  

International Nuclear Information System (INIS)

Staff from the Pacific Northwest Laboratory (PNL) performed measurements of the radioactive effluents emitted by the Army Pulse Radiation Facility (APRF). These measurements were performed by collecting the cooling air that passed by the APRF reactor as it operated, passing the air through filters to collect the particulates and iodines, and collecting samples of the air to be analyzed for noble gases. The reactor operated for four test runs, including two pulses and two steady state runs. After each reactor run, the filters were counted using gamma spectrometry to identify the nuclides and to determine the activity of nuclides deposited on the filters. The study provided radionuclide release fraction data that can be used to estimate the airborne emissions resulting from APRF operations. The release fraction for particulate fission products and radioiodines, as derived from these measurements, was found to be 8.9 x 10-6 for reactor pulses and 4.3 x 10-6 for steady state operation. These values compare to a theoretical value of 1.5 x 10-5

368

Measurements of neutron cross sections of radioactive waste nuclides  

Energy Technology Data Exchange (ETDEWEB)

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 {sup 137}Cs, {sup 135}Cs, {sup 90}Sr, {sup 99}Tc and {sup 129}I because of their large fission yields and long half-lives. The present authors have measured the neutron capture cross sections and resonance integrals of {sup 137}Cs, {sup 90}Sr and {sup 99}Tc. The purpose of this study is to measure the neutron capture cross sections and resonance integrals of nuclides, {sup 129}I and {sup 135}Cs 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 integral of {sup 135}Cs by using the JRR-3 Reactor because this measurement required a high flux reactor. On the other hand, those of {sup 129}I were measured at the Rikkyo Reactor because the product nuclides, {sup 130}I and {sup 130m}I, have short half-lives and this reactor is suitable for the study of short lived nuclide. In this report, the measurements of the cross section and resonance integral of {sup 135}Cs are described. To obtain reliable values of the cross section and resonance integral of {sup 135}Cs(n, {gamma}){sup 136}Cs reaction, a quadrupole mass spectrometer was used for the mass analysis of nuclide in the sample. A progress report on the cross section of {sup 134}Cs, a neighbour of {sup 135}Cs, is included in this report. A report on {sup 129}I will be presented in the Report on the Joint-Use of Rikkyo University Reactor. (author)

Katoh, Toshio [Gifu College of Medical Technology, Seki, Gifu (Japan); Harada, Hideo; Nakamura, Shoji; Tanase, Masakazu; Hatsukawa, Yuichi

1998-01-01

369

Measurement of the absolute branching ratio of the K+ -> pi+ pi0 (gamma) decay with the KLOE detector  

CERN Document Server

We have measured the absolute branching ratio of the K+ -> pi+ pi0 (gamma) decay, using about 20 million tagged K+ mesons collected with the KLOE detector at DAFNE, the Frascati phi-factory. Signal counts are obtained from the fit of the distribution of the momentum of the charged decay particle in the kaon rest frame. The result, inclusive of final-state radiation, is BR(K+ -> pi+ pi0 (gamma))=0.2065+/-0.0005_{stat}+/- 0.0008_{syst}.

Ambrosino, F; Antonelli, M; Archilli, F; Bacci, C; Beltrame, P; Bencivenni, G; Bertolucci, S; Bini, C; Bloise, C; Bocchetta, S; Bossi, F; Branchini, P; Campana, P; Capon, G; Capussela, T; Ceradini, F; Cesario, F; Chi, S; Chiefari, G; Ciambrone, P; Crucianelli, F; De Lucia, E; De Santis, A; De Simone, P; De Zorzi, G; Denig, A; Di Domenico, A; Di Donato, C; Di Micco, B; Doria, A; Dreucci, M; Felici, G; Ferrari, A; Ferrer, M L; Fiore, S; Forti, C; Franzini, P; Gatti, C; Gauzzi, P; Giovannella, S; Gorini, E; Graziani, E; Kluge, W; Kulikov, V; Lacava, F; Lanfranchi, G; Lee-Franzini, J; Leone, D; Martemyanov, M; Martini, M; Massarotti, P; Mei, W; Meola, S; Miscetti, S; Moulson, M; Müller, S; Murtas, F; Napolitano, M; Nguyen, F; Palutan, M; Pasqualucci, E; Passeri, A; Patera, V; Perfetto, F; Primavera, M; Santangelo, P; Saracino, G; Sciascia, B; Sciubba, A; Sibidanov, A; Spadaro, T; Testa, M; Tortora, L; Valente, P; Venanzoni, G; Versaci, R; Xu, G

2008-01-01

370

Absolute determination of the deuterium content of a heavy water sample D2O, measurement of its absolute density. Calculation of the absolute density of isotopically pure D216O  

International Nuclear Information System (INIS)

The absolute density of two heavy water samples rich in deuterium (with a grade higher than 99.9%) was determined with the hydrostatic method. The exact isotopic composition of this water (hydrogen and oxygen isotopes) was very carefully studied. A theoretical estimate allowed to get the absolute density value of isotopically pure D216O. This value was found to be 1104.750 kg.m-3 at t=22.3 deg C and under the pressure of one atmosphere

371

A twin type heat flow microcalorimeter for radioactivity measurements  

International Nuclear Information System (INIS)

A microcalorimeter is described which was developed and tested for measuring the activity of pure ? particle emitters. Two identically made calorimeter cells are used, each 46.5 mm i.d. and 54.0 mm deep and each fitted with thermomodules generating an emf of about 29 mV deg C-1. The thermal energy from the cells flows into a surrounding mass of aluminium (15 kg) embedded in 30 mm thick styrofoam. The entire assembly is then immersed into an open thermostated bath controlled by electric heaters an arrangement which facilitates acces for sample changing. The outputs of the modules (sensors) are connected in opposing polarities, the net output being amplified and this voltage signal is used to estimate the radioactivity in the samples. In order to demonstrate usefulness of this calorimeter, approximately 3.7 GBq(100 mCi) of tritiated water was measured. The result was compared with that of liquid scintillation counting method and found to be agreed within 5%. (author)

372

Results of radioactivity measurements in France during 1983  

International Nuclear Information System (INIS)

Various marine and continental sampling networks for the environmental monitoring of radioactivity of liquid waste discharges from French nuclear establishments have been set up by the Departement de Protection Sanitaire (DPS) since 1983. Measurements carried out on marine biological indicators: seaweeds, molluscs and fish caught all along the French shore, show that man-made radionuclide levels are locally higher both in the Channel near the release outlet of La Hague fuel reprocessing plant and in the influence area of the Rhone river waters in the Mediterranean sea. At the stations with the highest levels, the sanitary incidence of man-made radionuclides remains low, since it corresponds to a fraction in the range of 10-5 of the dose limit recommended by the International Commission on Radiological Protection. Continental measurements, especially those carried out on the crops from the agricultural area irrigated by the Compagnie Nationale d'Amenagement de la Region du Bas-Rhone et du Languedoc, corroborate the lack of transfers of radionuclides conveyed by the Rhone water to the agricultural produces of this region

373

Functional requirements document for measuring emissions of airborne radioactive materials  

International Nuclear Information System (INIS)

This document states the general functional requirements for systems and procedures for measuring emissions of airborne radioactive materials from facilities administered by the Westinghouse Hanford Company (WHC). The following issues are addressed in this document: lg-bullet definition of the program objectives lg-bullet selection of the overall approach to collecting the samples lg-bullet sampling equipment design lg-bullet sampling equipment maintenance and quality assurance issues. The following issues are not addressed in this document: lg-bullet air sampling in work areas or containments lg-bullet selection of specific on-line sample monitoring instrumentation lg-bullet analyzing collected samples lg-bullet reporting and interpreting results. The document provides equipment design guidance that is performance based rather than prescriptive. Locations from which samples are obtained should exhibit mixing of the contaminants with the airstream and acceptable air flow characteristics. Sample collection equipment and effluent and sample flow elements should meet defined performance standards. Quality control and assurance requirements specific to sample collection, equipment inspection, and calibration are presented. Key sample collection performance requirements are summarized in Section 5.4. 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

374

Measurement of natural radioactivity of the leaf Nefza (Oued belif)  

International Nuclear Information System (INIS)

Nefza region, specifically Oued Belif, has a unique geological diversity in Tunisia. That's why it was chosen to be a study of natural radioactivity. The results were encouraging and have allowed us to draw conclusions about the origin of the high natural radioactivity found in certain rocks.

375

On the calculation of the average in radioactivity measurements  

International Nuclear Information System (INIS)

Three different methods for averaging the independent experimental results in radioactivity measurements are compared by using computer simulation. The first method is newly introduced according to the maximum likelihood method. The second and third methods are the conventional simplest arithmetic and weighted means, respectively. The parent mean of the net counts per unit time, ?, is assumed to be identical in two measurements and the parent means of the background per unit time, ?1 and ?2, are different each other. The counting data of the sample ?? (?=1, 2), are generated by the Poisson random number generator, whose parent means are of (?+??)t?, respectively, where t? are the accumulation periods of the sample measurements. The background data are also generated with the parent means, ???? (?=1, 2), where ?? are the accumulation periods of the background. The generated data are analysed by the different three methods. In the new method, one can get non-linear simultaneous equations by differentiating the likelihood function with respect to ?, ?1 and ?2. The simultaneous equation can be solved by a successive approximation, and then the estimate of ? can be obtained. The simplest arithmetic mean is carried out for the sample counts per unit time subtracted by the backgrounds per unit time. The weighted mean is done in the saan is done in the same manner as the case of the Gaussian-distributed data. These processes are repeated 10,000 or 20,000 times and the arithmetic means of three estimates are independently calculated according to the methods. The new method and the simplest arithmetic mean denote the similar results, and give good estimates of the parent means, ?. The weighted mean does not give good estimates. The new method is most desirable for the analysis, if all of the original data in measurement are known. (J.P.N.)

376

Identification and elimination of half-synthetic wavelength error for multi-wavelength long absolute distance measurement  

International Nuclear Information System (INIS)

A multi-wavelength absolute distance measurement method based on synchronous occurrence and phase measurement of coarse and refined synthetic wavelength is proposed to remove the effect of vibration on the measurement distance. The phase value of refined synthetic wavelength is monitored to see if half-synthetic wavelength error occurs by judging whether it is near to 2? or 0. If yes, a new suitable refined synthetic wavelength is generated to re-measure the distance with phase near ?. A measuring system has been built with a He–Ne laser source and three acousto-optic frequency shifters for implementation of this method. A comparative measurement has been performed using a counting laser interferometer at a distance of 20 m. Actual measurements indicate that half-synthetic wavelength error has been identified and eliminated with uncertainty of smaller than 60 µm under laboratory conditions

377

Absolute nuclear material assay  

Science.gov (United States)

A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

Prasad, Manoj K. (Pleasanton, CA); Snyderman, Neal J. (Berkeley, CA); Rowland, Mark S. (Alamo, CA)

2012-05-15

378

Preparation of radioactive ''mixed'' waste samples for measurement of RCRA [Resource Conservation and Recovery Act] organic compounds  

International Nuclear Information System (INIS)

A radioactive ''mixed'' waste typically contains alpha-, beta-, or gamma-emitting radionuclides and varying quantities of semivolatile or volatile organic species, some or all of which may be named specifically by the Resource Conservation and Recovery Act (RCRA). Because there are no acceptable means available currently for disposing of these mixed wastes, they are presently stored above-ground in sealed drums. For this reason, analytical procedures which can determine RCRA organics in radioactive waste are necessary for deciding the proper approach for disposal. An important goal of this work is the development of methods for preparing mixed waste samples in a manner which allows the RCRA organics to be measured in conventional organic analysis laboratories without special precautions. Analytical procedures developed for handling mixed waste samples must satisfy not only the usual constraints present in any trace-level organic chemical determination, but also those needed to insure the protection of the operator from radioactive contamination. Consequently, procedures should be designed to use the least amount of radioactive sample commensurate with achieving acceptable sensitivity with the RCRA analytical methods. Furthermore, the unusual laboratory glassware which would normally be used should be replaced with disposable materials wherever possible, in order to reduce the ''clean-up'' time required, and thereby reduce the operator's exposure to radioactivity. Actual sample handling should be reduced to the absolute minimum. Finally, the final isolate must exhibit a sufficiently low level of alpha, beta, or gamma activity to permit detailed characterization in a conventional organic analysis laboratory. 4 refs., 5 tabs

379

Chernobyl in the 20th year. Radiation and radioactivity measurements in Turkey after Chernobyl  

International Nuclear Information System (INIS)

In the sixth part of the series contains discussions and analysis of radiation and radioactivity measurements carried out by Turkish Atomic Energy Authority during 20 years especially in the region of Black Sea and Thracia of Turkey. Radioactivity was measured on all kind of vegetables, atmosphere, water, soil etc. and all kind of exported/imported foods. The results are discussed and analysed

380

Measurements of radioactivity in former military personnel exposed to weapon debris  

International Nuclear Information System (INIS)

Sixteen former military personnel who were present at the Smoky atmospheric nuclear weapons test have been investigated for internal deposits of radioactivity. Whole-body and thorax ?-ray measurements, thorax and skeletal actinide measurements, and urinalyses for 239Pu and 90Sr were performed. No evidence of radioactivity in excess of that found in the general population was observed

381

Measurents of natural radioactivity in an underground hydroelectric power plant  

International Nuclear Information System (INIS)

In underground working places, especially when ventilation is not properly regulated, large amounts of natural radioactivity can be found. This can give rise to potential exposures of non-negligible magnitude. Direct measurements of gamma radiation and radon were carried out during excavation works for the construction of an hydroelectric plant in the north of Italy. After the construction of the plant, in order to reduce radon concentrations and to improve ventilation effectiveness, the main entry gate was motorized and automated. Then, in order to find the optimal speed for the fans located in the galleries and in the power plant, radon and airflow velocity were measured. Correlation data between airflow and radon concentrations were found. An automatic regulation system has been set up using air velocity detectors and slightly modifying the software for the control and regulation of the power plant. Measurements must be made in order to identify radon sources and evaluate quantitative contributions as a function of ventilation. Underground hydroelectric plants are provided with entry galleries as well as secondary galleries from which radon coming out from the soil and the walls can exhale in quantities that depend on the contents of 226Ra in the rocks and in the building materials. Other radon sources are the water coming out from the walls of the galleries and the water in the deep well located at the bottom of the power plant. Geological studies and mathematical models are useful means for the analysis of the relative contributions of the main sources as well as for the prediction of the effects deriving from modifications of the hydroelectric plant ventilation system or resulting from other important structural changes. (author)

382

Design and implementation of a vacuum compatible laser-based sub-nm resolution absolute distance measurement gauge  

International Nuclear Information System (INIS)

We describe the design and implementation of a vacuum compatible laser-based absolute distance measurement gauge with sub-nm resolution. The present system is compatible with operation in the 10-8 Torr range and with some minor modifications could be used in the 10-9 Torr range. The system is based on glancing incidence reflection and dual segmented diode detection. The system has been implemented as a focus sensor for extreme ultraviolet interferometry and microlithography experiments at Lawrence Berkeley National Laboratory's Advanced Light Source synchrotron radiation facility and 1? operational measurement noise floor of 0.26 nm has been demonstrated

383

Design and manufacture of multi-electrode ion chamber for absolute photon-flux measurements of soft x-rays  

Energy Technology Data Exchange (ETDEWEB)

In order to measure the absolute photon-flux of soft x-rays at the photon energy region from 500 eV to 1500 eV, a sealed gas ion chamber with multi-electrodes was designed and manufactured. Actually we succeeded in measuring the photon-flux at the soft x-ray beamline, BL23SU, in the SPring-8. This report concretely describes the design and the adjustment of the sealed gas ion chamber with multi-electrodes. (author)

Yoshigoe, Akitaka; Teraoka, Yuden [Japan Atomic Energy Research Inst., Kansai Research Establishment, Synchrotron Radiation Research Center, Mikazuki, Hyogo (Japan)

2001-03-01

384

Design and manufacture of multi-electrode ion chamber for absolute photon-flux measurements of soft x-rays  

International Nuclear Information System (INIS)

In order to measure the absolute photon-flux of soft x-rays at the photon energy region from 500 eV to 1500 eV, a sealed gas ion chamber with multi-electrodes was designed and manufactured. Actually we succeeded in measuring the photon-flux at the soft x-ray beamline, BL23SU, in the SPring-8. This report concretely describes the design and the adjustment of the sealed gas ion chamber with multi-electrodes. (author)

385

Absolute and relative dose measurements with Gafchromic EBT film for high energy electron beams with different doses per pulse.  

OpenAIRE

The authors have evaluated the accuracy, in absolute and relative dose measurements, of the Gafchromic EBT film in pulsed high-energy electron beams. Typically, the electron beams used in radiotherapy have a dose-per-pulse value of less than 0.1 mGy/pulse. However, very high dose-per-pulse electron beams are employed in certain linear accelerators dedicated to intraoperatory radiation therapy (IORT). In this study, the absorbed dose measurements with Gafchromic EBT in both low (less than 0.3 ...

Ricardi, Umberto; Fiandra, Christian; Ragona, Riccardo

2008-01-01

386

Direct and absolute temperature mapping and heat transfer measurements in diode-end-pumped Yb:YAG  

CERN Document Server

We report direct and absolute temperature measurements in a diode-end-pumped Yb:YAG crystal, using a calibrated infrared camera, with a 60-$\\mu$m spatial resolution. The heat transfer coefficient has been measured, for the first time to our knowledge, with four different types of thermal contact (H = 0.25, 0.28, 0.9 and 2.0 for bare contact, graphite layer, indium foil and heat sink grease respectively). The dynamics of thermal effects is also presented.

Chenais, S; Druon, F; Balembois, F; Georges, P; Chenais, Sebastien; Forget, Sebastien; Druon, Frederic; Balembois, Francois; Georges, Patrick

2004-01-01

387

Extraction simulations and emittance measurements of a Holifield Radioactive Ion Beam Facility electron beam plasma source for radioactive ion beams  

International Nuclear Information System (INIS)

The Holifield Radioactive Ion Beam Facility HRIBF at Oak Ridge National Laboratory has a variety of ion sources used to produce radioactive ion beams RIBs. Of these, the workhorse is an electron beam plasma EBP ion source. The recent addition of a second RIB injector, the Injector for Radioactive Ion Species 2 IRIS2, for the HRIBF tandem accelerator prompted new studies of the optics of the beam extraction from the EBP source. The source was modeled using SIMION V8.0, and results will be presented, including comparison of the emittances as predicted by simulation and as measured at the HRIBF offline ion source test facilities. Also presented will be the impact on phase space shape resulting from extraction optics modifications implemented at IRIS2.

388

Measurement of intrinsic radioactivity in a GSO crystal  

CERN Document Server

Scintillating crystal detectors offer potential advantages in low-energy low-background experiments for particle physics and astrophysics. The GSO crystal is an interesting detector to explore in future neutrino physics experiments. The contributions to background due to the various channels of intrinsic radio isotopes from the sup 2 sup 3 sup 2 Th and sup 2 sup 3 sup 8 U series are identified and studied with time-correlation analysis and detailed fits to the spectral shape. Good agreement is achieved between measured and simulated spectra, indicating that background suppression factors to the 10 sup - sup 2 -10 sup - sup 3 level are possible. The procedures can be adopted for background understanding and suppression in other low-count-rate experiments where the dominant source of background is from internal radioactivity. Based on 1656 h of data taking, limits on the double beta decay half-life for the various channels in sup 1 sup 6 sup 0 Gd are derived. The limits for the neutrinoless and the Majoron mode...

Wang, S C; Fujiwara, M

2002-01-01

389

Direct reaction measurements with a 132Sn radioactive ion beam  

International Nuclear Information System (INIS)

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 elastic scattering cross section. The magnitude of the nuclear effects, in the angular range studied, was found to be independent of the optical potential used, allowing the transfer data to be normalized in a reliable manner. The neutron-transfer reaction populated a previously unmeasured state at 1363 keV, which is most likely the single-particle 3p1/2 state expected above the N=82 shell closure. The data were analyzed using finite-range adiabatic-wave calculations and the results compared with the previous analysis using the distorted-wave Born approximation. Angular distributions for the ground and first-excited states are consistent with the previous tentative spin and parity assignments. Spectroscopic factors extracted from the differential cross sections are similar to those found for the one-neutron states beyond the benchmark doubly magic nucleus 208Pb.

390

Results of radioactivity measurements in French coastal waters during 1985  

International Nuclear Information System (INIS)

Various sampling networks for the environmental monitoring of levels from radioactive waste releases from french nuclear plants have been set up by the Departement de Protection Sanitaire (DPS) since 1983. In 1985, various marine and freshwater biological indicators were collected regularly on the Channel, Atlantic and Mediterranean shores and at the level of the lower Rhone river. As in the previous years, the results showed the prevailing effects of the releases from the LA HAGUE reprocessing plant on the Channel and of the Rhone waters on the Mediterranean sea. Measurements at the level of the lower Rhone showed a clear labelling of the Rhone river waters by 106Ru. The monitoring of ruthenium levels in various biological indicators from the Mediterranean shore supplied a good representation of the marine areas affected by the Rhone river. At the stations with the highest levels, the sanitary consequence of man-made radionuclides remained low, representing a fraction in the range of 10-5 of the dose limit recommended by the International Commission on Radiological Protection

391

Measurement of extremely low level radioactivity with imaging plate  

International Nuclear Information System (INIS)

It is possible to measure the geometrical distribution of extremely low level natural radioactivity contained in vegetables, meat etc. by utilizing a very high sensitivity of Imaging Plate for radiations. For this purpose, however, reduction of background(BG) radiations is necessary by using a shielding box of, for example, lead with a thickness of ?10 cm. Monte-Carlo simulation shows that BG image is given by electrons emitted from the inner surface of the shielding box under the interaction of ?-rays transmitted through the box rather than by the ?-rays themselves. In the case of lead box, the inner surface has to be covered with other materials to cut the ?-rays emitted from Bi-210 contained in lead. In the exposure of vegetables, meat etc. for 20 days or more, rotting, oozing-out of water, shape variation of the specimens must be avoided. The effect of C-14 ?-rays in making the latent image is negligibly small compared with K-40 ?-rays. (author)

392

Analysis of bleeding saps and radioactive measurements of deciduous trees  

International Nuclear Information System (INIS)

Samples of bleeding sap of Betula pendula Roth, Betula lutea L., Betula papyrifera L., Betula mandshuria L., Salix mielichoferi Saut., Cornus florida L., Evodea velutina L., Vitis amurensis L., Acer tartaricum L., Aesculus parviflora L., and Juglans regia L. in the botanical garden in Graz have been collected during springs of 1987, 1988, and 1989. After a special treatment (ion-exchange and freeze-drying) the bleeding saps have been searched for the compounds of sugars, amino acids and organic acids by gas-chromatrography. LAMMA-spectra showed the ion composition, and radioactivity measurements on leaves of the trees have also been made. In all bleeding saps sugars could be identified in various concentrations, mainly glucose and fructose. All trees showed nearly the same acid spectrum, and the most common ingredient was malic acid. In the bleeding saps of the Betulaceae and Juglans regia the major constituent was citrulline. In Acer tartaricum allantoine was present in large concentration. In Evodea velutina, Aesculus parviflora, Vitis amurensis and Cornus florida glutamin could be identified in large concentration. After the reactor accident of Tschernobyl in April 1986 the number of synthetic radionuclides increased and they could be identified. The LAMMA-spectra showed high contents of kalium and calcium in the bleeding saps. (author)

393

Savannah River Site Experiences in In Situ Field Measurements of Radioactive Materials  

International Nuclear Information System (INIS)

This paper discusses some of the field gamma-ray measurements made at the Savannah River Site, the equipment used for the measurements, and lessons learned during in situ identification and characterization of radioactive materials

394

Radioactivity Measurements in River Sediments and Aquatic Organisms of Kanyakumari District  

OpenAIRE

The present study was focused to assess the Natural radioactivity levels in river sediment samples and the associated organisms (fishes and molluscs) collected from Kanyakumari district. The gross and activity were measured using alpha scintillation counter and low beta counter. The natural radioactivity level is higher in sediment samples collected from Valliyar river near Eraniel and the level was minimum in sediments of Sittar. The radioactivity level of all the river sediments mainly depe...

Eugin shaji. J; Kannan C; Feroz Khan. M

2013-01-01

395

Ordinance on measures for the preparation of radioactive waste repositories (Ordinance on preparatory measures)  

International Nuclear Information System (INIS)

This Ordinance specifies the special licensing procedure provided for under Section 10(2) of the Federal Order of 6 October 1978 concerning the Atomic Energy Act whereby the Federal Council must grant permission before preparations for the construction of radioactive waste repositories may be undertaken. The Ordinance defines the preparatory measures, which include maps and plans of the area, a geological report, etc. It repeals the Ordinance of 24 October 1979 on the same subject. (NEA)

396

Biscuit-type thorium-232 reference sources for measuring radioactivity in naturally occurring radioactive materials (NORM)  

International Nuclear Information System (INIS)

In this study, biscuit-type thorium-232 reference sources were prepared with specific concentration (7 grams, 8 grams and 10 grams) of thorium nitrate (with the theoretical activity for each reference source calculated), for the efficiency calibration of the Gamma spectrometer with Multichannel Analyser (MC) Nal detector which is used for the quantification of approximate radioactivity values of the gamma emitting daughter nuclides of thorium-232 (Lead-212, Actinium-228, Thallium-208 and Bismuth-212) in the black mineral sand from Ombo, Northern Palawan (NORM sample). The biscuit reference source with 10 grams of thorium nitrate had the least uncertainty (per nuclide) in efficiency of the gamma spectrometer and therefore it was used for the calculation of the approximate radioactivity values of Lead-212, Actinium-228, Thallium-208 and Bismuth-212 in the NORM sample. We observed that the uncertainties in theoretical activity of the reference source and the uncertainty in efficiency of the spectrometer for the reference source used are proportional to the uncertainties in the calculation of the radioactivity in the NORM sample. Furthermore, the prepared biscuit reference source with 10 grams of thorium nitrate can be used for calculation of the approximate radioactivity values of the gamma emitting daughter nuclides of thorium-232 in other NORM samples. (author)

397

Measurement of absolute left ventricular volume from gated blood pool studies  

International Nuclear Information System (INIS)

A new method for obtaining absolute left ventricular volume from gated blood pool studies was evaluated in a torso phantom and in 35 patients who also underwent single-plane contrast ventriculograpy. Gated 400 left anterior oblique and static anterior views were acquired. Left ventricular volume at end-diastole was given by the ratio of the attenuation-corrected end-diastolic count rate from the gated study to the count rate per milliliter from a blood sample. Attenuation correction was made by dividing the end-diastolic count rate by e/sup -ud/, where u = the linear attenuation coefficient of water and d = the distance from the skin marker to the center of the left ventricle in the anterior view divided by sin 400 to yield the depth of left ventricle in the left anterior oblique view. In the phantom studies, the correlation between radionuclide and true volume was 0.99 (radionuclide = 1.03 true - 3 ml); the standard error of the estimate was 8 ml. In the patient studies, the radionuclide end-diastolic volume was used to calibrate the left ventricular time-activity curve, yielding left ventricular volume, throughout the cardiac cycle. The correlation between radionuclide and angiographic end-diastolic volume was 0.95 (radionuclide = 0.97 angiographic + 3 ml); the standard error of the estimate was 36 ml. The correlation between radionuclide and angiographic end-systolic volume was 0.95 (radionuclide = 1.01 angiographic + 1ml); the standard error 1 angiographic + 1ml); the standard error of the estimate as 3 ml. The method permits direct determination of absolute left ventricular volume without assumptions about the shape of the ventricle or the necessity of using regression equations to convert volume ''units'' to true volume

398

System parameters and measurement instrument parameters are not separately observable: Relational mass is observable while absolute mass is not  

CERN Document Server

A brief summary of the objections to the relational nature of inertial mass, gravitational mass and electric charge is presented. The objections are refuted by showing that the measurement process of comparing an instrument reference clock and a reference rod both obeying the laws of physics to a system obeying the same laws of physics results in relational quantities: inertial mass, gravitational mass and electric charge appear only as ratios. This means that scaling of the absolute inertial mass of every object in the universe by the same factor is unobservable (likewise for gravitational mass and electric charge). It is shown that the measurement process does not separate the instrument parameters from the system parameters. Instead a measurement produces functions of fundamental, dimensionless parameters such as the fine structure constant, electron-proton mass ratio and the proton gyro-magnetic factor. It is shown that the measurement of Planck's constant also results in such a function of these dimensio...

Holt, Craig R

2014-01-01

399

Studies of the absolute measurement of low-level natural environmental radiation using the normal-pressure ionization chamber  

International Nuclear Information System (INIS)

The characteristics and the measurement results of a normal-pressure dry-air ionization chamber of 21-liter cylindrical type with 0.5 cm-thick walls are given. A specially designed electrometer is capable of measuring current to within +- 0.5% accuracy. Alpha contamination, which is an important factor affecting the accuracy of the environmental measurements, is precisely evaluated. The uncertainty of the absolute measurement of the environmental radiation dose in free air is found to be +- 5.2%, of which +-2.2% is from inherent factors and +- 3.0% is from common factors. The fluctuation of the ionization current is also quantitatively evaluated as a function of the charge integration time. The precision for 10-min integration time is estimated to be +- 2.4% (2sigma) at 6 ?rads/h

400

Absolute measurements and simulations of x-ray line energies of highly charged ions with a double-crystal spectrometer  

International Nuclear Information System (INIS)

We present a recently constructed double-crystal spectrometer with the purpose of measuring line energies of inner-shell transitions in highly charged ions. Due to its geometrical features, this spectrometer enables absolute measurements of energies with an unprecedented accuracy. We have also developed an ab initio simulation code that allows us to obtain accurate line profiles and estimate geometric and diffraction profile uncertainties. We show the first proof-of-principle measurements on highly charged ions done with this spectrometer. In particular, we present the recent measurement of the M1 transition in He-like Ar with an accuracy of 2.5 ppm and compare it with results of quantum electro dynamic theory. (paper)

401

The effect probe into of the measurement radioactivity nuclide for TDCR method by change liquid scintillation sample volume test  

International Nuclear Information System (INIS)

Radioactivity Nuclide of 3H, 14C Solution by TDCR method measurement, introduce how change 3H, 14C sample volume test. The effect of Degree of accuracy is small for measurement radioactive nuclide. (authors)

402

Design and implementation of a vacuum-compatible laser-based subnanometer-resolution absolute distance measurement system  

Science.gov (United States)

We describe the design and implementation of a vacuum compatible laser-based absolute distance measurement system with subnanometer resolution. The presented system is compatible with operation in the 10-8-Torr range, and with some minor modifications it could be used in the 10-9-Torr range. The system is based on glancing incidence reflection and dual segmented diode detection. The system has been implemented as a focus sensor for extreme ultraviolet interferometry and microlithography experiments at Lawrence Berkeley National Laboratory's Advanced Light Source synchrotron radiation facility. A 3? operational noise floor of 0.78 nm has been demonstrated.

Naulleau, Patrick P.; Denham, Paul E.; Rekawa, Senajith

2005-01-01

403

Measurements of the Absolute Branching Fractions of B^\\pm --> K^\\pm X_{c\\bar c}  

OpenAIRE

We study the two-body decays of B^\\pm mesons to K^\\pm and a charmonium state, X_{c\\bar c}, in a sample of 210.5 fb^{-1} of data from the BaBar experiment. We perform measurements of absolute branching fractions BR(B^\\pm --> K^\\pm X_{c\\bar c}) using a missing mass technique, and report several new or improved results. In particular, the upper limit BR(B^\\pm --> K^\\pm X(3872)) J/\\psi\\pi^+\\pi^-)>4.2% will help in understanding the nature of the recently discovered X(3872).

Babar, The Collaboration; Aubert, B.

2005-01-01

404

Measurement of radioactive nuclides in the `Mayak` region  

Energy Technology Data Exchange (ETDEWEB)

The study of environmental contamination caused by anthropogenic impact and, primarily, by radioactive nuclides is one of the main scientific problems facing contemporary science. Radioecological monitoring, decision making on remediation of polluted areas need detailed information about distribution of radioactive nuclides in the terrestrial and aquatic ecosystems, knowledge about radioactive nuclide occurrence forms and migration patterns. Experimental tests of nuclear and thermonuclear weapon in atmosphere and underground, nuclear power engineering and numerous accidents that took place at the nuclear power plants (NPP), unauthorized dump of radioactive materials in various places of the ocean and pouring off the strongly dump of radioactive wastes from ships and submarine equipped with nuclear power engines made artificial radionuclides a constant and unretrievable component of the modern biosphere, becoming an additional unfavorable ecological factor. As regards Former Sovient Union (FSU) the most unfavorable regions are Southern Ural, zones suffered from Chernobyl Accident, Altay, Novaya Zemlya, some part of West Siberia near Seversk (Tomsk-7) and Zheleznogorsk (Krasnoyarsk-26). (orig.)

Myasoedov, B.F. [V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Novikov, A.P. [V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

1997-03-01

405

Measurement of radioactive nuclides in the 'Mayak' region  

International Nuclear Information System (INIS)

The study of environmental contamination caused by anthropogenic impact and, primarily, by radioactive nuclides is one of the main scientific problems facing contemporary science. Radioecological monitoring, decision making on remediation of polluted areas need detailed information about distribution of radioactive nuclides in the terrestrial and aquatic ecosystems, knowledge about radioactive nuclide occurrence forms and migration patterns. Experimental tests of nuclear and thermonuclear weapon in atmosphere and underground, nuclear power engineering and numerous accidents that took place at the nuclear power plants (NPP), unauthorized dump of radioactive materials in various places of the ocean and pouring off the strongly dump of radioactive wastes from ships and submarine equipped with nuclear power engines made artificial radionuclides a constant and unretrievable component of the modern biosphere, becoming an additional unfavorable ecological factor. As regards Former Sovient Union (FSU) the most unfavorable regions are Southern Ural, zones suffered from Chernobyl Accident, Altay, Novaya Zemlya, some part of West Siberia near Seversk (Tomsk-7) and Zheleznogorsk (Krasnoyarsk-26). (orig.)

406

Absolute flow measurements to obtain depth against discharge for sewers using bromine-82 and lithium as tracers  

International Nuclear Information System (INIS)

The methods used by the Water Research Centre Laboratory to obtain absolute discharge data in respect of partially full sewers are presented. Discharge recorders and depth gauges were calibrated by dilution methods using lithium and bromine-82 as water tracers. The Laboratory's 'extended gulp' technique is described and the relative merits of the dilution techniques and tracers used are discussed. Bromine-82 is considered to be the most suitable tracer for measurements at very high flowrates and where high accuracy is required. Lithium can be used at short notice and is simpler to apply in field situations. A description is given of several sets of flow measurements carried out in the Stevenage outfall to obtain estimates of the ultimate carrying capacity of the sewer - a concrete pipe of 1 m diameter. For part of the study the natural flow was augmented by releasing water from a water meadow to obtain a range of depths of liquid above the normal maximum and thus determine the complete depth/discharge characteristic. Data relating to sewers 0.3 to 1.5 m diameter are also given; these illustrate that absolute measurement data, ever over very restricted ranges of depth, can be most useful in estimating carrying capacities as a function of depth when utilized with theoretical formulae. Composite pipe roughness values have been estimated and the experimental data compared with predictions based on Manning's formula and the Colebrook-White equation. (author)ok-White equation. (author)

407

Development of Radioactive Inventory Evaluation System using 3D Shape and Multiple Radiation Measurement  

International Nuclear Information System (INIS)

The increase of the operating NPPs and the superannuation of the equipment in NPPs cause a large amount of the metal radioactive waste. Presently the metal radioactive wastes are stored in the temporary storage facility in NPPs because of the delay of the construction of the final disposal facility. The radioactive level of general metal radioactive wastes is low, and the radioactive level can be lowered by the simple decontamination process. If the radioactive wastes are disposed as the industry waste, the disposal cost is diminished largely. For the disposal of the radioactive wastes as the industrial wastes, the radioactive level of the target wastes are evaluated. It is difficult to know the position of the source term for most of the metal radioactive and the source term is distributed non-homogeneously. And the self-shielding effect of the metal material makes the evaluation more difficult. In this study, the radioactive inventory evaluation system for the metal radioactive waste is developed. For the correction of the uncertainty of the position and the non-homogeneity of the source term, the 3D shape and multiple radiation measurement are used. The existing gamma-ray measurement system for the metal radioactive waste cannot reflect the position and the distribution of the source term and the effect of self-shielding. This evaluation system suggested in this system can calculate the reasonable value regarding to the position and the distribution of the source term and the effect of self-shielding. By the calculation of the partial inventory of the target metal waste, the advantage in the application of the clearance criteria can be obtained

408

Radioactivity Measurement in the Detergent Products by Gamma Spectrometry  

International Nuclear Information System (INIS)

Our study focuses on the evaluation of the level of radioactivity in the detergents. We have determined the specific activities of gamma emitting radionuclides belonging to the natural families of uranium, thorium and potassium using gamma spectrometry. The activities of radionuclides (235U, 238U, 226Ra, 232Th, 40K) and their descendants are below the minimum detectable activity for dishwasher products, soaps, bleaches and shampoos, whereas they are found to levels considered very low (between 0,2 and 13 Bq/kg on average) in the products washes linens. These values are always lower than those of raw materials, what is explained by the conservation of radioactive material throughout the manufacturing process. The effective dose due to external exposure estimated below the regulatory standard recommended (<1 mSv / year), allows us to show that detergent products are not contaminated by radioactivity, are healthy and do not have harmful radiological impact on the consumer.

409

Measurement of Natural Radioactivity in Sand Samples Collected from Ad-Dahna Desert in Saudi Arabia  

OpenAIRE

Natural radioactivity is a source of continuous exposure to human beings. The natural radioactivity due to the presence of 226Ra, 232Th and 40K in sand samples collected from Ad-Dahna was measured by means of HPGe. The measured activity concentrations of radionuclides were compared with the worldwide reported data. Mean measured activity concentrations of 226Ra, 232

Alaamer, Abdulaziz S.

2012-01-01

410

Radioactivity measurement of 85Kr with position-sensitive proportional counter  

International Nuclear Information System (INIS)

Direct radioactivity measurement of 85Kr is difficult with ionization chambers, since it emits high-energy ?-rays (E?max=667 keV) which results in a severe wall effect. Also with proportional counters, the end-effect must be taken into account. The position-sensitive proportional counter (PSPC) method which can eliminate the end-effect was applied to direct measurement of 85Kr radioactivity. In the measurement, logarithmic amplifiers were employed to clearly distinguish between ?-ray signals and noise signals, and to eliminate digital error in the calculation of position information. The radioactivity of 85Kr was determined with ±0.80% standard deviation. (orig.)

411

Application of the permeation to the production of low radioactive calibrated gas flows. Low radioactive tritium measurement  

International Nuclear Information System (INIS)

The permeation of compounds (HT, HTO, 131ICH3, and 129ICH3) through organic membranes in view of producing low radioactive calibrated gas flows has been studied. This process of which the diffusion is the main stage enables respecting certain conditions (choice of the membrane, temperature, partial pressure differential) our aims to be reached with a good accuracy. In order to measure radioactivity of tritiated standard gases, a detector was built. This detector is an Oeschger type proportional counter with a total volume of 17.4 dm3 and an useful volume of 3.9 dm3. In the conditions of operation, the background is of 1.7.10-6 I s-1 cm-3. The counter coupled with a feed-rack enables various samples to be measured and it is possible in the best conditions to detect some 10-11 ?Ci cm-3 NTP

412

Measurement of radioactivity in building materials in Serbia  

International Nuclear Information System (INIS)

This work presents a comprehensive study of natural radioactivity in 720 building materials imported in Serbia in 2012. Radioactivity concentrations of 226Ra, 232Th and 40K in the studied samples range from -1, respectively. The maximum values of 226Ra and 232Th activity concentrations were found in zirconium mineral, while the highest 40K activity concentration was in the feldspar. Based on the obtained radionuclide concentrations, radium equivalent activity, air absorbed dose rate, annual effective dose, external and internal hazard indices, gamma and alpha index due to radon inhalation were evaluated to assess the potential radiological hazard associated with these building materials. (author)

413

A proposal for absolute determination of inertial mass by measuring oscillation periods based on the quasi-elastic electrostatic force  

Science.gov (United States)

A quasi-elastic electrostatic oscillation method is proposed for the absolute determination of inertial mass, which is distinguished from the gravitational mass measurement in the watt balance experiment. The value of the kilogram is determined by comparing oscillation periods of the quasi-elastic electrostatic oscillator with different test masses and applying different dc voltages on a symmetrical twin-Kelvin-capacitor system. The required measuring quantities for this method include the capacitance, voltage, vertical distance and oscillation periods, which in principle can be measured with high accuracy. In addition, this experiment is insensitive to the air buoyancy and the heating problem, and it can be operated in air. Both the theory and experimental verifications are presented.

Li, Shisong; Zhang, Zhonghua; He, Qing; Li, Zhengkun; Lan, Jiang; Han, Bing; Lu, Yunfeng; Xu, Jinxin

2013-02-01

414

Measurement of absolute response functions and detection efficiencies of an NE213 scintillator up to 600 MeV  

International Nuclear Information System (INIS)

Absolute neutron response functions and detection efficiencies of an NE213 liquid scintillator that was 12.7 cm in diameter and 12.7 cm in thickness were measured for neutron energies between 15 and 600 MeV at the Weapons Neutron Research facility of the Los Alamos Neutron Science Center. The experiment was performed with continuous-energy neutrons on a spallation neutron source by 800-MeV proton incidence. The incident neutron flux was measured using a 238U fission ionization chamber. Measured response functions and detection efficiencies were compared with corresponding calculations using the SCINFUL-QMD code. The calculated and experimental values were in good agreement for data below 70 MeV. However, there were discrepancies in the energy region between 70 and 150 MeV. Thus, the code was partly modified and the revised code provided better agreement with the experimental data.

415

Measurement of absolute response functions and detection efficiencies of an NE213 scintillator up to 600 MeV  

Energy Technology Data Exchange (ETDEWEB)

Absolute neutron response functions and detection efficiencies of an NE213 liquid scintillator that was 12.7 cm in diameter and 12.7 cm in thickness were measured for neutron energies between 15 and 600 MeV at the Weapons Neutron Research facility of the Los Alamos Neutron Science Center. The experiment was performed with continuous-energy neutrons on a spallation neutron source by 800-MeV proton incidence. The incident neutron flux was measured using a {sup 238}U fission ionization chamber. Measured response functions and detection efficiencies were compared with corresponding calculations using the SCINFUL-QMD code. The calculated and experimental values were in good agreement for data below 70 MeV. However, there were discrepancies in the energy region between 70 and 150 MeV. Thus, the code was partly modified and the revised code provided better agreement with the experimental data.

Kajimoto, Tsuyoshi, E-mail: kajimoto@kune2a.nucl.kyushu-u.ac.jp [Kyushu University, Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Shigyo, Nobuhiro [Kyushu University, Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Sanami, Toshiya [High Energy Accelerator Research Organization, Oho, Tsukuba, Ibaraki 305-0801 (Japan); Ishibashi, Kenji [Kyushu University, Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Haight, Robert C.; Fotiades, Nikolaos [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2011-02-11

416

Absolute left ventricular volume from gated blood pool imaging with use of esophageal transmission measurement  

International Nuclear Information System (INIS)

A new method for determining absolute left ventricular (LV) volume from equilibrium gated blood pool images was validated in 36 patients by comparing gated blood pool (GBP) imaging with contrast ventriculography (CV) using both Simpson's rule (SR) and area-length (AL) calculations. The technique is geometry-independent and is the first to correct for tissue attenuation with use of an in vivo point source. An orally administered capsule containing 1 to 2 mCi of technetium-99m (Tc-99m) sulfur colloid is used for this purpose. Left ventricular volumes are determined by dividing attenuation and background-corrected count rates obtained from semiautomated LV regions of interest by the count rate per milliliter from a blood sample. The correlation between GBP and CV (SR) was 0.96 (CV [SR] . 0.99 GBP + 1.32 ml; standard error of the estimate [SEE] . 21.2 ml) for diastole and 0.97 (CV [SR] . 0.93 GBP - 0.03 ml; SEE . 11.9 ml) for systole. The correlation between GBP and CV (AL) was 0.92 (CV [AL] . 0.90 GBP + 16.72 ml; SEE . 27.8 ml) for diastole and 0.95 (CV [AL] . 0.87 GBP + 4.56 ml; SEE . 14.4 ml) for systole. The method is noninvasive and can be performed easily as part of routine gated blood pool imaging and analysis

417

Time-of-flight system with a movable ion detector for absolute measurement of cyclotron beam energy  

Science.gov (United States)

A time-of-flight system for determining the absolute energy of ion beams has been developed for the azimuthally varying field (AVF) cyclotron at Japan Atomic Energy Agency (JAEA). Ion detectors, a microchannel-plate detector and a plastic scintillation detector, were applied to the system in order to achieve high time resolution measurement of the flight time and to cover a wide range of beam intensity in combination with a beam attenuator. The change of the flight length, performed by moving the plastic scintillation detector with flexible bellows, allows determination of the mean beam energy only from the relative measurement of the flight time and the flight length without knowing their absolute values. A maximum movable distance of 2m yields the difference in the time of flight from 16to94ns for the energy range of ion beams accelerated by the JAEA AVF cyclotron. The time-of-flight system even with the 2m change in the flight length achieves accurate energy determination of the order of 0.1%, since the relative measurement has an advantage of elimination of the uncertainties in determination of the time zero and the length zero. The time-of-flight measurement with the relative measurement also allows estimation of the beam energy spread without conventional expensive systems such as a magnetic spectrometer. By comparing the widths of the time-of-flight spectra of ions accumulated at different flight lengths, we have estimated the energy spread. In order to reduce the labor process of the coincidence detection of ions in the time-of-flight measurement, we have also accomplished a simple estimation method for mean beam energy determination with a beam bunch, naturally modulated with the acceleration RF of the cyclotron. The mean beam energy has been obtained from the shift of the beam bunch centroids at different flight lengths in the time-of-flight spectrum.

Okumura, S.; Kurashima, S.; Miyawaki, N.; Yoshida, K.; Fukuda, M.

2005-11-01

418

Method for separation and measurement of 63Ni in radioactive waste  

International Nuclear Information System (INIS)

63Ni is an activation product found in radioactive wastes that is of great importance for waste treatment and disposal. The determination of radionuclides present in radioactive wastes generated from nuclear power plants is important for estimating the radioactivity concentrations of long lived alpha and beta-emitting radionuclides in the solid waste forms. A sequential separation procedure has been developed for determination of 63Ni in various radioactive wastes generated from nuclear power plants. Because of its radioactive property of emitting only low energy ? rays of 67-keV as maximum energy, 63Ni measurement calls for special techniques. The method used involves anion exchange, precipitation of Ni as Ni-dimethyl glyoxime complex for 63Ni measurement and using simulated waste samples (paper, textile and graphite). Nickel was founded following atomic absorption. (authors)

419

Contribution to the measurement of absolute activity of electron capture decaying nuclides. Determination of the fluorescence yield of some elements  

International Nuclear Information System (INIS)

The object of this work is the study of techniques of measurement of the absolute activity of electron capture nuclides. Two methods have been specially studied. Determination of the number of X rays emitted from the K shell due to the reorganization of atomic electrons following electron capture. This measurement was made with a high pressure (5 kg/cm2) 4? proportional counter. The absorption in the source and the backing were also studied. To determine the absolute activity it is necessary to know the fluorescence yield and the different capture probabilities PL and PK. When the electron capture is followed by ? emission (within the resolution time of the coincidence circuit) the activity was determined through the X-? coincidence method. In such a case it is not necessary to know the fluorescence yield and the capture probabilities. Various corrections - dead time, chance coincidences - were also studied. This method minimizes the decay scheme corrections. By applying these two methods to the following nuclides: Cr51, Mn54 and Zn65, the corresponding fluorescence yields have been determined: vanadium ?K = 0.191 ±0.002, chromium ?K = 0.262 ± 0.002 and copper ?K = 0.390 ± 0.004. (author)

420

ZnS(Ag) coating layer thickness verification of one small scintillation cell for 222Rn/220Rn absolute measurement  

International Nuclear Information System (INIS)

The detection efficiency of one small scintillation cell for 222Rn/220Rn absolute measurement can be affected by ZnS (Ag) coating layer thickness on the inner wall of the small scintillation cell. The ? detection efficiency of 10 mg/cm2 thickness ZnS (Ag) coating layer has been tested and verified using a plating reference source (241 Am). The solid angle correction factor is calculated by analysis and MCNP simulation methods. The absorption correction of air layer on ? particle has been discussed. The source of uncertainty has been analysed. The results indicate the ? detection efficiency of 10 mg/cm2 thickness ZnS (Ag) coating layer is between 102.4%-103.1% while the uncertainty is less than 5.44%. In the uncertain range ? detection efficiency of it is considered as 100%. 10 mg/cm2 thickness ZnS (Ag) coating layer can be used to apply on the inner wall of the small scintillation cell for 222Rn/220Rn absolute measurement. (authors)

421

Absolute K-shell emission line brightness measurements of laser-irradiated targets at the National Ignition Facility (NIF)  

Science.gov (United States)

X-ray K-shell-emission-line sources generated with under-dense laser-irradiated targets, including Ge and Zn pre-pulsed foils, Ge-doped silica aerogel, Kr gas targets, and a stainless-steel-lined cavity, were developed for radiographic and imaging applications on the NIF. Tailored laser pulses delivering up to 750 kJ of 3w light on target with peak laser power ranging from 14 to 150 TW were used to optimize laser-to-x-ray conversion efficiency (CE) for the various targets. The time-integrated, K-shell emission line brightness was measured using an absolutely calibrated, elliptically curved Bragg crystal spectrometer, measuring x rays between 6 and 16 keV. Absolute x-ray yields up to ˜10 kJ/sr for the He? plus satellite emission from the mid-Z elements and corresponding CE up to 2.5% into He? and ˜6% into 6.4-16 keV emission are reported and compared with simulated spectra.

Barrios, M. A.; Regan, S. P.; Fournier, K. B.; May, M.; Colvin, J.; Olson, R.; Kane, J.; Widmann, K.; Bradley, D.; Collins, G. W.

2012-10-01

422

Measures to prevent breaches in the security of radioactive materials  

International Nuclear Information System (INIS)

The objective of this paper, which is the result of the co-operation between the Swedish Board of Customs, the Swedish Radiation Protection Institute, the Security Police and the Swedish Nuclear Power Inspectorate, is to give an idea of the national prevention system as to illicit trafficking of nuclear materials and other radioactive sources. (author)

423

A process and apparatus for measuring radioactive radiation  

International Nuclear Information System (INIS)

Reference is made to devices and arrangements for detecting ambient radioactivity, commonly known as radiameters. The arrangement described comprises a number of detectors having different spectral sensitivities arranged so that the sensitivity of the arrangement as a whole is substantially independent of wavelength over a predetermined range of the spectrum. Integrating and amplifying means are provided. (author)

424

Measurement of radioactivity in the environment - Soil - Part 1: General guidelines and definitions  

International Nuclear Information System (INIS)

This part of ISO 18589 specifies the general requirements to carry out radionuclides tests on soil sample, including sampling. This part of ISO 18589 is addressed to people responsible for determining the radioactivity present in soils for the purpose of radiation protection. This may concern soils from gardens and farmland, urban or industrial sites, as well as soil not affected by human activities. This part of ISO 18589 is applicable to all laboratories regardless of the number of personnel or the extent of the scope of testing activities. When a laboratory does not undertake one or more of the activities covered by this part of ISO 18589, such as planning, sampling or testing, the requirements of those clauses do not apply. This part of ISO 18589 is to be used in conjunction with other parts of ISO 18589 that outline the setting up of programmes and sampling techniques, methods of general processing of samples in the laboratory and also methods for measuring the radioactivity in soil. Its purpose is the following: - define the main terms relating to soils, sampling, radioactivity and its measurement; - describe the origins of the radioactivity in soils; - define the main objectives of the study of radioactivity in soil samples; - present the principles of studies of soil radioactivity; - identify the analytical and procedural requirements when measuring radioactivity in soil. This part of ISO 18589 is applicable if radionuclide measurements for the purpose of radiclide measurements for the purpose of radiation protection are to be made in the following cases: - initial characterization of radioactivity in the environment; - routine surveillance of the impact of nuclear installations or of the evolution of the general territory; - investigations of accident and incident situations; - planning and surveillance of remedial action; - decommissioning of installations or clearance of materials. This part of ISO 18589 is not intended to cover scientific investigations of soil radioactivity and therefore does not apply to aspects of such measurements

425

Absolutely Continuous Compensators  

OpenAIRE

We give sufficient conditions on the underlying filtration such that all totally inaccessible stopping times have compensators which are absolutely continuous. If a semimartingale, strong Markov process X has a representation as a solution of a stochastic differential equation driven by a Wiener process, Lebesgue measure, and a Poisson random measure, then all compensators of totally inaccessible stopping times are absolutely continuous with respect to the minimal filtration...

Janson, Svante; M Baye, Sokhna; Protter, Philip

2010-01-01

426

Measuring Radioactivity from Fukushima Daiichi in New Mexico  

International Nuclear Information System (INIS)

On March 11, 2011, the Fukushima Daiichi nuclear power plant was damaged by the tsunami that followed the 'Great East Japan Earthquake,' and the reactor subsequently leaked radioactive material. In response, LANL augmented the routine ambient (AIRNET) and stack (Rad-NESHAP) measurements with three high-volume samplers: No.167 at the Old White Rock Fire Station; No.173 at the TA-49 gate, and No.211 at the Los Alamos Medical Center. Previous accidents, such as the Three-Mile-Island accident in 1979 and the Chernobyl accident in 1986, indicated that the most likely releases were (a) the noble gases: krypton and xenon; and (b) the volatile elements: cesium, tellurium, and iodine. At the latitude of Fukushima, the predominant winds across the Pacific Ocean are from west to east, and models predicted that the plume would arrive in the western US on about March 18. By this time the shorter-lived isotopes would have decayed. Therefore, the expected radionuclides were xenon-133, cesium-134, cesium-136, cesium-137, tellurium-132, iodine-131, and iodine-132. As expected, cesium-134, cesium-136, cesium-137, tellurium-132, iodine-131, and iodine-132 were all detected by all three high-volume samplers during March 17-21. The concentrations peaked during the March 24-28 period. After this, concentrations of all nuclides declined. In general, the concentrations were consistent with those measured by the EPA RadNet system and many other monitoring systems throughout the world. At the ring systems throughout the world. At the time of writing, preliminary results from the AIRNET and Rad-NESHAP systems are being reported. More detailed results are described in LA-UR-11-10304 and will be reported in full in the annual environmental report for 2011. All previous releases from nuclear reactors have been dominated by noble gases, primarily krypton and xenon, which are not measured by the high-volume samplers or the AIRNET system. However, in sufficient concentrations these and other fission products would be detected by NEWNET. Consistent with this possibility, all NEWNET detectors recorded an increase of 0.2 (micro)R/h from March 19-1, followed by an additional increase of 0.1 (micro)R/h on March 24 (Figure 1). The consistency of the NEWNET stations is indicated by the error bars, which represent the standard error of the mean of the individual stations. Over the next 10 days, the NEWNET readings declined with approximately the 5-day half life of xenon-133, returning to near normal levels on April 2. After this, any further decrease was masked by high radon concentrations on April 3, by a weather system that moved into New Mexico on April 4, and by rainfall on April 6-9. Furthermore, it is likely that all NEWNET detectors responded to a gradually increasing trend in terrestrial radiation during the month of March as the ground dried out. It is difficult to distinguish the hypothetical effects of xenon-133 from the fluctuations of radon decay products. However, at present we do not have an alternative hypothesis for the sharp increase that was observed in all NEWNET stations from March 19-21. Perhaps some of the increase was caused by radon or terrestrial radiation, in which case the observed increase is an upper limit to that caused by releases from Fukushima. LANL data are consistent with those of the EPA RadNet monitoring system. The EPA has repeatedly stated that 'The levels detected are far below levels of concern.'

427

Underground processes deduced from radioactivity measurements in groundwater  

International Nuclear Information System (INIS)

It is well known that various nuclides such as 4He, 40Ar or 222Rn that are produced by radioactive decay in a rock matrix can be found in groundwater. The level of other radionuclides that are used in groundwater dating is often influenced by underground production, especially in uranium-rich formations. Examples include 36Cl, 39Ar and I29I. We have recently measured underground produced 37Ar and 85Kr in Stripa groundwaters. The escape rate of a particular nuclide from its site of production to the water phase depends on many parameters, such as the microscopic distribution of elements, porosity, recoil energy, diffusion constant and others. Measured concentrations of radionuclides in groundwater may therefore either represent underground produced levels or levels originating from the atmosphere or a combination of both origins. In Fig. 1 we present a schematic illustration of both contributions for the nuclides that are most often used in hydrology. Subsurface produced contributions have been identified for the following isotopes: 4He, 36C1, 37Ar, 39Ar, 40Ar excess, 85Kr, 129I and 222Rn. From our measurements of some of these nuclides and from published results we summarize the following conclusions relating to these nuclides: -The 4He concentrations are usually higher than the maximtrations are usually higher than the maximum levels estimated for in situ production over a reasonable time. Migration from other layers of the aquifer has to be assumed. - 36Cl concentrations sometimes increase more or less linearly with the CI content, possibly indicating dissolution of Cl from rock with subsurface equilibrated 36C1. Dating of such waters is not possible without a detailed knowledge of Cl- evolution. - 37Ar activities are especially high in groundwaters if fracture fillings contain large amounts of Ca. For escape into the water recoil processes seem to be more important than diffusion. - 39Ar activities are found to exceed atmospheric concentrations in granitic groundwaters; dating is not possible. Whether there is also significant production of 39Ar in sedimentary groundwaters is under investigation. - 40Ar excesses may be an indication of very old groundwater or of strong weathering of rock surfaces. -Subsurface produced 85Kr activities have up to now only been detected in Stripa groundwaters where uranium is enriched at the surface of fracture filling minerals. In young waters atmospheric origin dominates. - 129I activities are a combination of atmosphere and subsurface origin. Since iodine dissolution may be important it is difficult to separate the two origins. - 222Rn concentrations in groundwaters are highly variable. Uranium concentrations at the surface of minerals can give high concentrations; recoil is the important process for escape. - The combination of isotope methods may help to understand the various effects which determine production, escape and dilution of nuclides

428

Absolute measurement of the energies of alpha-particles emitted by sources of 252Cf and 227Ac  

International Nuclear Information System (INIS)

Absolute energy measurements of ?-particles from sources of 252Cf and 227Ac by magnetic spectrometry are described. The sources were prepared at AERE, Harwell and measurements carried out using the 1800 uniform-field spectrometer at BIPM followed the well-established technique applying cellulose-nitrate films (Kodak LR115) for track detection. The following values and uncertainties were obtained: 252Cf: E0=(6118.24±0.04) keV, E43=(6075.77±0.11) keV; 250Cf: E0=(6030.35±0.20) keV; 227Ac: E0=(4953.37±0.14) keV, E13=(4940.8±0.8) keV. (orig.)

429

Absolute measurement of the energies of alpha-particles emitted by sources of 252Cf and 227Ac  

Science.gov (United States)

Absolute energy measurements of ?-particles from sources of 252Cf and 227Ac by magnetic spectrometry are described. The sources were prepared at AERE, Harwell and measurements carried out using the 180° uniform-field spectrometer at BIPM followed the well-established technique applying cellulose-nitrate films (Kodak LR115) for track detection. The following values and uncertainties were obtained: 252Cf: E ? 0 = (6118.24±0.04) keV, E ? 43 = (6075.77±0.11) keV; 250Cf: E ? 0 = (6030.35±0.20) keV; 227Ac: E ? 0 = (4953.37±0.14) kev, E ? 13 = (4940.8±0.8) keV.

Rytz, A.; Wiltshire, R. A. P.; King, M.

1986-12-01

430

Absolute measurement of the energies of alpha-particles emitted by sources of /sup 252/Cf and /sup 227/Ac  

Energy Technology Data Exchange (ETDEWEB)

Absolute energy measurements of ..cap alpha..-particles from sources of /sup 252/Cf and /sup 227/Ac by magnetic spectrometry are described. The sources were prepared at AERE, Harwell and measurements carried out using the 180/sup 0/ uniform-field spectrometer at BIPM followed the well-established technique applying cellulose-nitrate films (Kodak LR115) for track detection. The following values and uncertainties were obtained: /sup 252/Cf: E/sub 0/=(6118.24+-0.04) keV, E/sub 43/=(6075.77+-0.11) keV; /sup 250/Cf: E/sub 0/=(6030.35+-0.20) keV; /sup 227/Ac: E/sub 0/=(4953.37+-0.14) keV, E/sub 13/=(4940.8+-0.8) keV.

Rytz, A.; Wiltshire, R.A.P.; King, M.

1986-12-15

431

Absolute frequency measurements on the 2S{yields}3S transition of lithium-6,7  

Energy Technology Data Exchange (ETDEWEB)

The frequencies of the 2S-3S two-photon transition for the stable lithium isotopes were measured by cavity-enhanced Doppler-free laser excitation that was controlled by a femtosecond frequency comb. The resulting values of 815 618 181.57(18) and 815 606 727.59(18) MHz, respectively, for {sup 7}Li and {sup 6}Li are in agreement with previous measurements but are more accurate by an order of magnitude. There is still a discrepancy of about 11.6 and 10.6 MHz from the latest theoretical values. This is comparable to the uncertainty in the theoretical calculations, while uncertainty in our experimental values is more than a hundred-fold smaller. More accurate theoretical calculation of the transition frequencies would allow extraction of the absolute charge radii for these stable isotopes, which in turn could improve nuclear charge radii values for the unstable lithium isotopes.

Sanchez, Rodolfo; Ewald, Guido; Geppert, Christopher; Kluge, H-Juergen; Winters, Danyal F A; Noertershaeuser, Wilfried [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt (Germany); Zakova, Monika; Andjelkovic, Zoran; Kraemer, Joerg; Nothhelfer, Matthias; Tiedemann, Dirk [Institut fuer Kernchemie, Johannes Gutenberg-Universitaet Mainz, Fritz-Strassman-Weg 2, D-55128 Mainz (Germany); Bushaw, Bruce A [Chemical Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Dasgupta, Kamalesh [Bhabha Atomic Research Center, Mumbai 400085 (India)], E-mail: R.Sanchez@gsi.de

2009-07-15

432

Radio frequency cavity analysis, measurement, and calibration of absolute Dee voltage for K-500 superconducting cyclotron at VECC, Kolkata  

Energy Technology Data Exchange (ETDEWEB)

Variable Energy Cyclotron Centre has commissioned a K-500 superconducting cyclotron for various types of nuclear physics experiments. The 3-phase radio-frequency system of superconducting cyclotron has been developed in the frequency range 9-27 MHz with amplitude and phase stability of 100 ppm and {+-}0.2{sup 0}, respectively. The analysis of the RF cavity has been carried out using 3D Computer Simulation Technology (CST) Microwave Studio code and various RF parameters and accelerating voltages ('Dee' voltage) are calculated from simulation. During the RF system commissioning, measurement of different RF parameters has been done and absolute Dee voltage has been calibrated using a CdTe X-ray detector along with its accessories and known X-ray source. The present paper discusses about the measured data and the simulation result.

Som, Sumit; Seth, Sudeshna; Mandal, Aditya; Paul, Saikat; Duttagupta, Anjan [Variable Energy Cyclotron Centre, Kolkata (India)

2013-02-15

433

Determination of critical assembly absolute power using post-irradiation activation measurement of week-lived fission products  

International Nuclear Information System (INIS)

The work presents a detailed comparison of calculated and experimentally determined net peak areas of longer-living fission products after 100 h irradiation on a reactor with power of ?630 W and several days cooling. Specifically the nuclides studied are 140Ba, 103Ru, 131I, 141Ce, 95Zr. The good agreement between the calculated and measured net peak areas, which is better than in determination using short lived 92Sr, is reported. The experiment was conducted on the VVER-1000 mock-up installed on the LR-0 reactor. The Monte Carlo approach has been used for calculations. The influence of different data libraries on results of calculation is discussed as well. - Highlights: • Measured and calculated net peak areas of selected longer living isotopes. • Determination of absolute reactor power. • Discrepancies between calculation and experiment. • Effect of data libraries on calculational results

434

Absolute measurement of gauge block without wringing using tandem low-coherence interferometry  

International Nuclear Information System (INIS)

A novel method of gauge block measurement without wringing onto a glass platen is proposed. By using tandem low-coherence interferometry to perform remote measurements, wringing is rendered unnecessary. To measure its length, a gauge block for measurement without wringing is set several millimeters above a glass platen that is positioned on a triangle interferometer such that the distances between the surfaces of the block and the reflection surface of the platen can be measured from opposite directions. By using tandem low-coherence interferometry with a He–Ne laser as a reference length standard, gauge blocks with nominal lengths of 5, 10 and 75 mm have been measured remotely with an expanded uncertainty of about 86 nm. (paper)

435

Study on Method of Asphalt Density Measurement Using Low Level Radioactive Isotope  

International Nuclear Information System (INIS)

The fundamental cause of damage to road pavement is insufficient management of asphalt density during construction. Currently, asphalt density in Korea is measured in a laboratory by extracting a core sample after construction. This method delays the overall time of measurement and therefore it is difficult to achieve real-time density management. Using a radioactive isotope for measuring asphalt density during construction reduces measuring time thus enabling realtime measurement. Also, it is provided reliable density measurement to achieve effective density management at work sites. However, existing radiological equipment has not been widely used because of management restrictions and regulations due to the high radiation dose. In this study, we employed a non-destructive method for density measurement. Density is measured by using a portable gamma-ray backscatter device having a radioactivity emission of 100 ?Ci or less (notice No. 2002-23, Ministry of Science and Technology, standards on radiation protection, etc.), a sealed radioactive source subject to declaration

436

Framework for preparing and performing absolute radiometric measurements using electrooptical instruments for the earth observations  

Science.gov (United States)

The complex of measurements necessary for high-quality radiometric measurements of the Earth to be performed using space electrooptical instruments, including hyperspectrometric instruments, has been considered. This complex was developed in order to maintain the uniformity of measurements according to Russian legislation. In addition to organizational measures, it is necessary to determine the interrelation between radiometric data and geophysical parameters received using these data and to solve the methodological problems of the Earth observation instrument (EOI) radiometric calibration and in-orbit verification of EOI radiometric characteristics. The considered approaches are largely close to the statements of the international document "Quality Assurance Framework for Earth Observation—QA4EO".

Panfilov, A. S.; Gavrilov, V. R.; Sapritsky, V. I.

2014-12-01

437

Absolute determination of the effect of scattering and fluorescence on x-ray attenuation measurements  

International Nuclear Information System (INIS)

We investigate the effect of x-ray scattering and fluorescence upon measurements of the x-ray mass attenuation coefficient. Measurements of scattering and fluorescence are obtained from a comparison of attenuation measurements using different sized apertures to admit varying amounts of the scattering and fluorescence into the detectors. The result of such a comparison is found to be in good agreement with a theoretical calculation of the fluorescent and scattered photons reaching the ion chambers and, under our experimental conditions, decreases the measured attenuation coefficients of silver by up to 0.2%

438

A simple method for the measurement of radioactivity of samples separated by gas chromatography  

International Nuclear Information System (INIS)

Gas chromatographs with flame ionization detector can be used to determine the radioactivity (14C) of separated peaks. After a suitable change in the detector output the combustion product 14CO2 can be trapped by hyamine hydroxyde and measured by liquid scintigraphy. 90% of peak activity can be collected and measured, thus the method can be applied to determine the distribution and specific radioactivity of the components separated by gas chromatography. (author)

439