WorldWideScience

Sample records for absolute radioactivity measurements

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

    International Nuclear Information System (INIS)

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

  3. 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

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

    International Nuclear Information System (INIS)

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

  5. 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)

  6. Radioactivity measurement

    International Nuclear Information System (INIS)

    The radioactivity measurement in this chapter refers to nuclear analytical technique for the assessment of radioactivity in various type and form samples particularly the environmental and food samples. The following subjects are discussed: radionuclide measurement, sampling, radiochemical separation, sample preparation, radionuclide separation, source preparation, detection method - alpha counting, low background ?/? counting system, scintillation counter, alpha spectrometry, beta counting, photon counting, activity determination, statistical considerations, and quality assurance. The topic titled detection method, covers the principle, instrumentation, operational procedure and application for each method discussed

  7. Measurement of the absolute \

    Energy Technology Data Exchange (ETDEWEB)

    Aunion, Jose Luis Alcaraz; /Barcelona, IFAE

    2010-07-01

    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.

  8. Radioactivity and its measurement

    CERN Document Server

    Mann, W B; Garfinkel, S B

    1980-01-01

    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

  9. Measurement of radioactive aerosols

    International Nuclear Information System (INIS)

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

  10. The class of absolute decomposable inequality measures

    OpenAIRE

    Bosmans, Kristof; Cowell, Frank

    2009-01-01

    We provide a parsimonious axiomatisation of the complete class of absolute nequality indices. Our approach uses only a weak form of decomposability and does not require a priori that the measures be differentiable.

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

    CERN Document Server

    Wang Jian Qing; Yao Yan Ling; Jia Xue Wen

    2003-01-01

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

  12. Absolute measurement of hyperspectral and angular reflection.

    Science.gov (United States)

    Hwang, Jisoo

    2014-09-20

    A new instrument for absolute measurement of hyperspectral and angular reflection is presented. The instrument determines absolute values of angular reflection quantities in a wavelength range from 380 to 780 nm with a 3 nm spectral resolution by using a white source and a CCD-based spectroradiometer. Through uncertainty evaluation, the measurement uncertainty is determined as 1.4%-2.9% (k=2) for white diffuse material of Spectralon. The gonioreflectometric determination and an integrating-sphere-based reflection measurement traceable to KRISS spectral reflectance scale are compared by determining hemispherical reflectance, which results in agreement in their uncertainties. PMID:25322100

  13. Precision absolute positional measurement of laser beams

    OpenAIRE

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

    2013-01-01

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

  14. Precision absolute positional measurement of laser beams.

    Science.gov (United States)

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

    2013-04-20

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

  15. Absolute Radiometric Measurements in Space: ARMS

    Science.gov (United States)

    Martin, J. E.; Fox, N. P.

    1992-12-01

    The Absolute Radiometric Measurements in Space (ARMS) project proposes the development of a new primary radiometric standard for use in space traceable to the SI system of units. The standard, the Cryogenic Solar Absolute Radiometer (CSAR) will be capable of measuring the total irradiance of the Sun with an uncertainty of 0.01 percent, and a resolution of 0.001 percent, more than a factor ten improvement over existing instruments. ARMS was submitted to ESA in response to a call for opportunities for Columbus precursor flights and CSAR is currently on the provisional payload of Eureca 3.

  16. New absolute measurements of the solar spectrum

    Science.gov (United States)

    Burlov-Vasiljev, K. A.; Gurtovenko, E. A.; Matvejev, Yu. B.

    1995-03-01

    During 1986-1989 at the high-altitude station on the Peak Terskol, Caucasus (h = 3000 m) absolute measurements of the solar disk-center intensity were performed. The observations were carried out with the specialized solar telescope (D = 23 cm, F = 3 m) and grating spectrometer (F = 2 m, grating 140 x 150 mm, 600 grooves mm-1). The ribbon tungsten lamps used for absolute calibration were calibrated to the USSR standard of spectral intensity and were also compared with the irradiance standard of the PMO/WRC (Davos, Switzerland), with the lamps used in the Alma-Ata Observatory (Kazakhstan) and in Simferopol University for absolute measurements of stellar spectra. Methods and apparatus were improving step by step during 1985-1988. Special care was paid to the study of all possible sources of errors, in particular to the method of correction for atmospheric extinction, to polarization properties of optical elements of the apparatus, and to establishing the most reliable absolute calibration system. Finally, the observations performed during 1989 utilized only the refined methods and apparatus. As a result, the absolute integrals of the solar disk-centre intensity for 1-nm wide spectral bands in the range 310-685 nm are available. We estimate the total error is 2.5% at 310 nm and 2.1% at 680 nm. The absolute irradiance for 5-nm wide spectral bands is also obtained. We compare our results with results by Neckel and Labs (1984), with the irradiance filter measurements performed in PMO/WRC and calibration of the Sun's spectral irradiance to the stellar irradiance standard Vega by Lockwood (1992). Our results show a systematic difference with data by Neckel and Labs in the near-ultraviolet. The results by Neckel and Labs are probably underestimated in this spectral range by 8%.

  17. An absolute measure for a key currency

    Science.gov (United States)

    Oya, Shunsuke; Aihara, Kazuyuki; Hirata, Yoshito

    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.

  18. 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

  19. Absolute measurement of the GANIL beam energy

    International Nuclear Information System (INIS)

    The energy of the GANIL cyclotron beam was measured on-line during the 208Pb+208Pb elastic scattering experiment 'Search for Color van der Waals Force in the 208Pb+208Pb Mott scattering' with an absolute precision of 7x10-5 at ?1.0 GeV, which represents an improvement of one order of magnitude over previous absolute energy measurements. The energy was deduced from the time of flight between two beam-scanners, which only partially intercept the beam, situated on a straight line and separated by ?48.0 m. It was found that the nomial beam energy was in good agreement with the present results. (orig.)

  20. Absolute measurements of fission cross sections

    International Nuclear Information System (INIS)

    Absolute neutron fission cross sections measurements of 235U, 238U and 239Pu have been made at 13.9 and 14.6 MeV with a double 4? ionization chamber. The associated particle method with the time-of-flight technique was used. Our final values of sigma sub(nf)(235U), sigma sub(nf)(238U), sigma sub(nf)(239Pu), sigma sub(nf)(238U)/sigma sub(nf)(235U) and sigma sub(nf)(239Pu)/sigma sub(nf)(235U) are compared to previous data. A sigmasub(nf)(235U) absolute measurement has been made at 2.5 MeV using two references: the scattering cross section of 1H and the directional long counter. Preliminary results is compared to previous data. (author)

  1. Measurement of absolute gravity acceleration in Firenze

    Directory of Open Access Journals (Sweden)

    M. de Angelis

    2011-01-01

    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.

  2. Absolute method of measuring magnetic susceptibility

    Science.gov (United States)

    Thorpe, A.; Senftle, F.E.

    1959-01-01

    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.

  3. Radioactivity measurements principles and practice

    CERN Document Server

    Mann, W B; Spernol, A

    2012-01-01

    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

  4. 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

  5. Absolute intensity measurements in the vacuum ultraviolet

    Science.gov (United States)

    Samson, James A. R.

    1986-01-01

    The basic principles governing the construction and use of absolute detectors are discussed. The absolute detector must be constructed to insure collection of all ions and to insure that no secondary ionization occurs. The fundamental standard for the absolute detection of VUV radiation and X-rays is based on the ionizing properties of the radiation. The principle of the ionization chamber is described; the wavelength range of the ion chamber is from Xe threshold at 102.2 nm to the double ionization threshold of He at 15.7 nm. The use of Geiger or proportional counters as an absolute standard for wavelengths less than 30 nm and less than 10 nm in the soft X-ray region is examined. Various types of transfer standards such as thermocouples, photodiodes, and photocathodes, and the procedures for calibrating a detector are considered.

  6. 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.)

  7. Measurement of radioactivity in steel

    International Nuclear Information System (INIS)

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

  8. 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)

  9. Measurement of weak radioactivity

    CERN Document Server

    Theodorsson, P

    1996-01-01

    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

  10. 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)

  11. In vivo absorption spectroscopy for absolute measurement

    OpenAIRE

    Furukawa, Hiromitsu; Fukuda, Takashi

    2012-01-01

    In in vivo spectroscopy, there are differences between individual subjects in parameters such as tissue scattering and sample concentration. We propose a method that can provide the absolute value of a particular substance concentration, independent of these individual differences. Thus, it is not necessary to use the typical statistical calibration curve, which assumes an average level of scattering and an averaged concentration over individual subjects. This method is expected to greatly re...

  12. 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.)

  13. Radioactivity measurements and control solutions

    International Nuclear Information System (INIS)

    In our department, in the last years, a new line of production has been developed devoted to the radioactivity measurements (portal monitor, gamma source detector, neutron monitor). Instruments of different design (hand-held, portals or steady-state) are intended for detection and locating of radioactive sources. Monitors are intended to detect radioactive and special nuclear materials in vehicles, pedestrians, luggage, as well as for illegal traffic prevention of radioactive sources. Monitors provide audio and visual alarm signals when radioactive and/or special nuclear materials are detected. Neutron dosimeters are designed for the determination of dose equivalent rate around neutron generators or sources. All devices can be recommended for use to officers of customs, border guard and emergency services, civil defense, fire brigades, police and military departments, nuclear research or power facilities. Incorporating micro controllers and new design, our products span almost all the spectra of radioactivity detection (gamma, beta, X and neutrons). No special knowledge is needed to operate these instruments as all service functions are performed automatically (self-tests, background updating and threshold calculation). The Portal monitor is intended to be a checkpoint in contamination control or in unauthorized traffic of radioactive materials. The portal monitor can be installed both in open, unprotected to environmental conditions areas or in enclosed areas. It mayditions areas or in enclosed areas. It may be used at pedestrian cross border points, at check points of Nuclear Power Plants, enterprises of nuclear industry, weapons manufacturing and storage plants, nuclear waste disposal and storage sites, at the entrances to steel plants, the post-offices and airports, the governmental offices, banks, private companies etc. The monitor provides audio alarming signals when radioactive and/or special nuclear materials are detected. The monitor consists in a portal frame, which sustains 5 detectors. Each detector is an assembly consisting in a plastic scintillator, a photomultiplier and the associated electronics, all these components being mounted inside an aluminum cylindrical case. The specifications are: - Detects at least 1 Ci radioactivity spread all over the inspected body in a 20 Roentgen/h overall background; - Maximum detectable radioactivity, 10 Ci; - Acquisition time between 1 to 10 seconds. The Neutron Monitor is derived from the Bonner Spectrometer. The Bonner Spectrometer description is quite simple: A proportional counter filled with Helium 3 at a pressure value between 2 and 6 atmospheres is the detecting element. It is coated with a thick layer of hydrogen-rich material such as polyethylene. The output signal is measured by the current in the counter wire when it is biased to about +1000 volts. Our Neutron Monitor is a portable, battery powered monitor for dose equivalent rate measurements around reactors, accelerators and other neutron generating installations or sources. The instrument measures the neutron dose equivalent rate in units of Sv/h. It is important to note that we need to know the neutron energies to be measured so that the appropriate energy response correction factors are coded into the instrument driving calibrations. If these a priori data is not available the Neutron Monitor can only offer plain counts/second. The appropriate diameter for the polyethylene sphere was chosen to be 5 inches (127 mm). The instrument is equipped with a microprocessor and a 2 x 16 character display unit along with two push buttons. This simple setup configuration permits to choose the acquisition time base and the display mode (counts or Sv). Its specifications are: - Dose rate range,1 Sv/h to 100 mSv/h (neutron spectrum information is required before calibration); - Energy response, thermal range to 14 MeV; - Detector, He-3 proportional counter surrounded by 127 mm polyethylene sphere (SP9). The portable gamma source sniffer consists of a NaI(Tl) crystal, a photomultiplier and the associated electronics, all

  14. An All Fiber White Light Interferometric Absolute Temperature Measurement System

    Directory of Open Access Journals (Sweden)

    Jeonggon Harrison Kim

    2008-11-01

    Full Text Available Recently the author of this article proposed a new signal processing algorithm for an all fiber white light interferometer. In this article, an all fiber white light interferometric absolute temperature measurement system is presented using the previously proposed signal processing algorithm. Stability and absolute temperature measurement were demonstrated. These two tests demonstrated the feasibility of absolute temperature measurement with an accuracy of 0.015 fringe and 0.0005 fringe, respectively. A hysteresis test from 373K to 873K was also presented. Finally, robustness of the sensor system towards laser diode temperature drift, AFMZI temperature drift and PZT non-linearity was demonstrated.

  15. 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

  16. Absolute luminosity measurements with the LHCb detector at the LHC

    OpenAIRE

    Ajaltouni, Z; Alkhazov, G.; Archilli, F; Bauer, T.; Belous, K.; Ben-Haim, E.; Benson, S.; Van Beuzekom, M.; Blusk, S.; Bondar, N.; Brett, D; Burducea, I; Buytaert, J(European Organization for Nuclear Research (CERN), Geneva, Switzerland); CHARPENTIER, P; Clemencic, M.

    2012-01-01

    Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic ''van ...

  17. Measuring radioactivity in the body

    International Nuclear Information System (INIS)

    Techniques of measuring the total amount of radioactivity in the body of a living person as well as the principal applications of such measurements were reviewed at a Symposium on Whole Body Counting held in Vienna from 12 to 16 June 1961. The whole body counters can be divided into two broad groups: (a) counters for the radiation protection surveillance of the general public and radiation workers, capable of detecting extremely low levels of radioactivity in the human body, and (b) counters for medical research and diagnosis, designed to check the retention and excretion of radioactive substances administered to patients for metabolic and pathological studies. In both cases, the primary requirement is that the counter must be able to measure the total activity in the body. In recent years, there has been a remarkable development of the instruments and techniques for such measurements. One of the main purposes of the symposium in Vienna was to discuss how best to use these highly sophisticated instruments

  18. Measurement of radioactivity in Norway

    International Nuclear Information System (INIS)

    A nation-wide network of 11 monotoring stations for continuous registration of radioactivity in the air has been established in Norway. Via the telecommunication network, collected data are dayly automatically transmitted to the Norwegian Institute for Air Research (NILU). High radiation levels trigger an alarn for immediate transmission. The monotoring system and experiences in connection with its operation are described, and results from measurements in 1988 are presented. 14 figs

  19. Measurement of radioactivity in Norway

    International Nuclear Information System (INIS)

    A nation-wide network of 11 monitoring stations for continous registration of radioactivity in the air has been established in Norway. Via the telecommunication network, collected data are dayly automatically transmitted to the Norwegian Institute for Air Research (NILU). High radiation levels trigger an alarm for immediate transmission. The monitoring system and experiences in connection with its operation are described. Results from measurements in 1989 are presented. 18 figs

  20. Effects of natural radioactivity on food radioactivity measurement

    International Nuclear Information System (INIS)

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

  1. Absolute quantum yield measurement of powder samples.

    Science.gov (United States)

    Moreno, Luis A

    2012-01-01

    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

  2. Absolute measurement of anti ? for 252Cf

    International Nuclear Information System (INIS)

    Neutron yields were determined by measuring the activities produced in the INEL manganese bath. Of the three fission methods used, the neutron-fission coincidence method was found to be the most consistent and reliable. The value of 252Cf anti ? obtained by these measurements was 3.764

  3. Absolute measurement of specific activity of 133Ba solution

    International Nuclear Information System (INIS)

    The paper describes absolute measurement of specific activity of 133Ba solution by 4?X (L.S)-? coincidence method. The coincidence counting equations are derived. Total uncertainty (3?) of measuring result is less than 2%. Comparing with measuring results by HPGe ?-spectrometer and 4??(pc)-? coincidence installation, they are agreeable within 0.3%

  4. The absolute measurement and analysis of 198Au activation

    International Nuclear Information System (INIS)

    198Au has a series of merits, such as the simple disintegration Chart, the single isotope constitute, the clear activation section, the high purity and the easy machining. Therefore, 198Au is used the first choice for the neutron flux absolute measurement. The activations absolute measurement for a set of 198Au samples which have been activated in reactor is finished through a suit of new type 4??-? coincidence measurement device which is designed by ourselves in lab. By compare, these measurement values and theory values accord in range of uncertainty, the most uncertainty is less than 1.2%. We can draw a conclusion that the activation absolute measurement of this set of 198Au samples is reliable. (authors)

  5. Absolute Quantum Yield Measurement of Powder Samples

    OpenAIRE

    Moreno, Luis A.

    2012-01-01

    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.

  6. Absolute density measurements in the middle atmosphere

    Directory of Open Access Journals (Sweden)

    M. Rapp

    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

  7. On the Absolute Continuity of the Blackwell Measure

    Science.gov (United States)

    Bárány, Balázs; Kolossváry, István

    2015-04-01

    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.

  8. Quality Assurance In Radioactivity Measurements

    International Nuclear Information System (INIS)

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

  9. Absolute continuity of hyperbolic invariant measures for endomorphisms

    International Nuclear Information System (INIS)

    We prove that, for a C2 non-invertible but non-degenerate map f on a compact Riemannian manifold without boundary, a hyperbolic invariant measure ? is absolutely continuous with respect to the Lebesgue measure on the manifold if, under a condition on the Jacobian of the map, the measure satisfies two entropy formulae for positive exponents [13] and negative exponents [7], respectively. This implies that the entropy production e?(f) = 0 if and only if ? << Leb

  10. Absolute measurement of the spectral reflection factor using photon detectors

    International Nuclear Information System (INIS)

    The absolute reflectometer was developed on the basis of the theory for the integrating sphere. To measure monochromatic flux in the equipment a photomultiplier EMI type 9558 AM with S-20 photocathode was used. The following investigations were carried out: 1.Determination of the dependence of the photocurrent from the supply voltage of the photomultiplier. 2. Finding out the fault of the measuring system, constituted by the photomultiplier and the measuring device, according to Clark's method

  11. 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)

  12. Absolute luminosity measurements with the LHCb detector at the LHC

    CERN Document Server

    Aaij, R; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amhis, Y; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Arrabito, L; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Bailey, D S; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, C; Bauer, Th; Bay, A; Bediaga, I; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Brisbane, S; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Caicedo Carvajal, J M; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Charles, M; Charpentier, Ph; Chiapolini, N; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Collins, P; Constantin, F; Conti, G; Contu, A; Cook, A; Coombes, M; Corti, G; Cowan, G A; Currie, R; D'Almagne, B; D'Ambrosio, C; David, P; De Bonis, I; De Capua, S; De Cian, M; De Lorenzi, F; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Deissenroth, M; Del Buono, L; Deplano, C; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Eames, C; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; Elsasser, Ch; d'Enterria, D G; Esperante Pereira, D; Estève, L; Falabella, A; Fanchini, E; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garra Tico, J; Garrido, L; Gaspar, C; Gauvin, N; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Gregson, S; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Haefeli, G; Haen, C; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harji, R; Harnew, N; Harrison, J; Harrison, P F; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hofmann, W; Holubyev, K; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kandybei, S; Karacson, M; Karbach, T M; Keaveney, J; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Koblitz, S; Koppenburg, P; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kukulak, S; Kumar, R; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, L; Li Gioi, L; Lieng, M; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Luisier, J; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinez Santos, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McGregor, G; McNulty, R; Mclean, C; Meissner, M; Merk, M; Merkel, J; Messi, R; Miglioranzi, S; Milanes, D A; Minard, M-N; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Musy, M; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nardulli, J; Nasteva, I; Nedos, M; Needham, M; Neufeld, N; Nguyen-Mau, C; Nicol, M; Nies, S; Niess, V; Nikitin, N; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Pal, B; Palacios, J; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Paterson, S K; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C

    2012-01-01

    Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic ``van der Meer scan'' method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overall precision of 3.5\\% in the absolute lumi...

  13. New pulsed photoacoustic technique for measuring absolute optical absorption coefficient

    OpenAIRE

    Egerev, S.; Lyamshev, L.; Pashin, A.; Fokin, A.

    1994-01-01

    Pulsed photoacoustic spectroscopy (PAS) technique for measuring absolute optical absorption coefficient requiring no additional measurements is presented. It is based on determination of amplitude-time characteristics of PA signal generated in air surrounding sample under investigation. PA signal is excited by short laser pulse. Sample is placed in a three-chamber PA cell. Time dependence of PA signal expected in different chambers of PA cell is derived. Water absorption coefficient at IR wav...

  14. Absolute gravity acceleration measurement in atomic sensor laboratories

    Science.gov (United States)

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

    2012-03-01

    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.

  15. Absolute bunch length measurements by incoherent radiation fluctuation analysis

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-09-29

    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.

  16. Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

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

    CERN Document Server

    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

    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))%.

  18. Measurement of absolute photoluminescence quantum efficiencies in conjugated polymers

    Science.gov (United States)

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

    1995-07-01

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

  19. Precision Absolute Beam Current Measurement of Low Power Electron Beam

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-01

    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.

  20. Strategy for the absolute neutron emission measurement on ITER.

    Science.gov (United States)

    Sasao, M; Bertalot, L; Ishikawa, M; Popovichev, S

    2010-10-01

    Accuracy of 10% is demanded to the absolute fusion measurement on ITER. To achieve this accuracy, a functional combination of several types of neutron measurement subsystem, cross calibration among them, and in situ calibration are needed. Neutron transport calculation shows the suitable calibration source is a DT/DD neutron generator of source strength higher than 10(10)?n/s (neutron/second) for DT and 10(8)?n/s for DD. It will take eight weeks at the minimum with this source to calibrate flux monitors, profile monitors, and the activation system. PMID:21033851

  1. Radioactivity. Nuclear radiation and measured variables

    International Nuclear Information System (INIS)

    The leaflet of the German Atomforum e.V. on radioactivity describes the different radiations: alpha, beta, gamma and neutron radiation. The discussed measuring variables are Becquerel (activity) and Sievert (radiation doses). Radiation sources and radiation effects are shortly described.

  2. Model YZ-1 radioactive contamination measuring meter

    International Nuclear Information System (INIS)

    This paper introduces an instrument for measuring the radioactive contamination. Some home-made CMOS integrated circuits were adopted in the instrument. It provides a six-digit display. Its highest counting rate is 106/sec. It can work on AC or DC voltage and its working current is less than 72 mA. It is a protable instrument and can be used in laboratories to measure radioactivity of the samples

  3. Absolute and specific measures of research group excellence

    CERN Document Server

    Mryglod, O; Holovatch, Yu; Berche, B

    2012-01-01

    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...

  4. Absolute measurement of 126Sn radionuclide concentration with AMS

    Science.gov (United States)

    Gartenmann, P.; Golser, R.; Haas, P.; Kutschera, W.; Suter, M.; Synal, H.-A.; Wagner, M. J. M.; Wild, E.

    1996-06-01

    A new attempt has been made at the Zurich AMS facility for absolute measurements of isotopic ratios in connection with a project for the determination of the half-life of 126Sn [P. Haas et al., this issue, following paper]. A {126Sn }/{Sn} ratio of (9.23 ± 0.87) × 10 -6 was measured in material extracted from spent fuel rods of a nuclear power plant. Several specific problems had to be solved. For the separation of the isobaric interference of 126Te the method of projectile X-ray detection was applied. A gas ionization chamber was used to determine 126(Sn + Te) in a second independent way. To study mass fractionation effects, several stable tin isotopes were measured. A detailed description of the experimental setup and the measuring procedure is given. The results and the various sources of uncertainties are discussed.

  5. Absolute measurement of 126Sn radionuclide concentration with AMS

    International Nuclear Information System (INIS)

    A new attempt has been made at the Zurich AMS facility for absolute measurements of isotopic ratios in connection with a project for the determination of the half-life of 126Sn P.Haas et al., this issue, following paper. A 126Sn/Sn ratio of (9.23±0.87).10-6 was measured in material extracted from spent fuel rods of a nuclear power plant. Several specific problems had to be solved. For the separation of the isobaric interference of 126Te the method of projectile X-ray detection was applied. A gas ionization chamber was used to determine 126(Sn+Te) in a second independent way. To study mass fractionation effects, several stable tin isotopes were measured. A detailed description of the experimental setup and the measuring procedure is given. The results and the various sources of uncertainties are discussed. (orig.)

  6. 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)

  7. National and international traceability in radioactivity measurements

    International Nuclear Information System (INIS)

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

  8. 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)

  9. Deconstructing European Poverty Measures: What Relative and Absolute Scales Measure

    Science.gov (United States)

    Burkhauser, Richard V.

    2009-01-01

    Forster and d'Ercole (2009) outline the dominant method of conceptualization and operationalization of European poverty measures that informed the EU in its development of the questionnaire for the European Union--Survey of Income and Living Conditions (EU-SILC). They do so in the context of their explanation of how the Organization for Economic…

  10. NKS 1999 intercomparison of measurements of radioactivity

    International Nuclear Information System (INIS)

    34 laboratories have returned radioactivity measurements on six different environmental samples. The samples were analysed for their content of gamma emitters, Sr-90, transuranics and Tc-99. The samples materials are described and the results presented. Some scatter was observed in measurements of Cs-137 in low-level samples such as dry milk, meat and hay. The scatter was less pronounced for sediments and seaweed material that had higher levels of radioactivity. In general, the most of the results were consistent with a few laboratories reporting outlying values. An exception was seawater where no clear agreement could be found for the activity of Cs-137. (au)

  11. 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)

  12. Absolute measurement of undulator radiation in the extreme ultraviolet

    International Nuclear Information System (INIS)

    The spectral brightness of undulator radiation emitted by the model PMU-1 incorporated in the SOR-RING, the dedicated synchrotron radiation source in Tokyo, has been studied in the extreme ultraviolet region from 21.6 to 72.9 eV as a function of the electron energy #betta#, the field parameter K, and the angle of observation THETA in the absolute scale. A series of measurements covering the first and the second harmonic component of undulator radiation was compared with the fundamental formula lambdasub(n)=lambda0/2n#betta#2(1+K2/2+#betta#2THETA2), and the effects of finite emittance were studied. The brightness at the first peak was smaller than the theoretical value, while an enhanced second harmonic component was observed. (orig.)

  13. Measured and modelled absolute gravity changes in Greenland

    DEFF Research Database (Denmark)

    Nielsen, Jens Emil; Forsberg, René

    2014-01-01

    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.

  14. Environmental radioactivity measurement intercomparison exercise 1990

    International Nuclear Information System (INIS)

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

  15. 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)

  16. Radioactivity monitoring network: Measurements 1987

    International Nuclear Information System (INIS)

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

  17. System for measuring radioactivity of labelled biopolymers

    International Nuclear Information System (INIS)

    A system is described for measuring radioactivity of labelled biopolymers, comprising: a set of containers adapted for receiving aqueous solutions of biological samples containing biopolymers which are subsequently precipitated in said containers on particles of diatomite in the presence of a coprecipitator, then filtered, dissolved, and mixed with a scintillator; radioactivity measuring means including a detection chamber to which is fed the mixture produced in said set of containers; an electric drive for moving said set of containers in a stepwise manner; means for proportional feeding of said coprecipitator and a suspension of diatomite in an acid solution to said containers which contain the biological sample for forming an acid precipitation of biopolymers; means for the removal of precipitated samples from said containers; precipitated biopolymer filtering means for successively filtering the precipitate, suspending the precipitate, dissolving the biopolymers mixed with said scintillator for feeding of the mixture to said detection chamber; a system of pipelines interconnecting said above-recited means; and said means for measuring radioactivity of labelled biopolymers including, a measuring cell arranged in a detection chamber and communicating with said means for filtering precipitated biopolymers through one pipeline of said system of pipelines; a program unit electrically connected to said electric drive, said means for acid precipatation of biopolymers, said means for the removal of precipitated samples from said containers, said filtering means, and said radioactivity measuring device; said program unit adapted to periodically switch on and off the above-recited means and check the sequence of the radioactivity measuring operations; and a control unit for controlling the initiation of the system and for selecting programs

  18. Flow measurement of blood radioactivity in animals

    International Nuclear Information System (INIS)

    In order to permit flow measurement of blood radioactivity in an animal after establishing extracorporeal circulation, counting cells were constructed of various plastic scintillator materials. The cell was placed in a liquid scintillation spectrometer replacing the sample vial. Stable and reproducible counting rates were obtained only with cells made of blue Altustipe plastic. The counting efficiency was 1.8%. Using this detection system, continuous records were produced of blood radioactivity in miniature pigs after administration of 14C-urethane and [14C]methyl-piperazinyl pyrazino benzoxazepine maleate

  19. Nondestructive measurement of environmental radioactive strontium

    Directory of Open Access Journals (Sweden)

    Saiba Shuntaro

    2014-03-01

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

  20. Apparatus for measuring a concentration of radioactivity

    International Nuclear Information System (INIS)

    Disclosed is an apparatus for measuring concentration of radioactivity in a fluid circulating in a cooling system or a disposal system, etc., of a nuclear power plant (e.g. coolant), the apparatus having a plurality of sampling tubes with different diameters depending on the intensities of radioactivity, and the sampling tubes having valves for switching from one fluid to another fluid. The sampling tubes are connected to the system to a discharge pipe, and are disposed in the proximity of a radiation detector adapted to issue a signal representative of radiation. The issued signal is supplied to a multichannel pulse height analyzer and a data processing system providing an indication of the concentrations of radioactivities for respective radionuclides

  1. 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)

  2. Environmental radioactivity - problems in activity measurements

    International Nuclear Information System (INIS)

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

  3. Absolute bioavailability of [14C] genistein in the rat; plasma pharmacokinetics of parent compound, genistein glucuronide and total radioactivity.

    Science.gov (United States)

    Coldham, Nick G; Zhang, Ai-Qin; Key, Pauline; Sauer, Maurice J

    2002-01-01

    The systemic plasma pharmacokinetics of genistein were determined in rats to evaluate the absolute oral bioavailability and make comparison with similar data in the literature derived from humans subjects. The plasma concentrations of genistein, genistein glucuronide and carbon-14 were determined by LC-MS/MS and liquid scintillation counting following oral and intravenous dosing with [14C]genistein (4 mg kg(-1) body weight). The absorption of total radioactivity from the gut, (parent compound and metabolites), was 56 and 111% in male and female rats, respectively. In contrast, the absolute oral bioavailability of genistein in male and female rats was 7 and 15%. There was a significant (Pgross overestimation of genistein bioavailability. Pharmacokinetic parameters Cmax, Tmax and AUC were similar to those reported in humans, which supports the use of the rat model for genistein toxicity studies. PMID:12587954

  4. Embedded north-seeker for automatic absolute magnetic DI measurements

    Science.gov (United States)

    Gonsette, Alexandre; Rasson, Jean

    2014-05-01

    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.

  5. Environmental radioactivity measurement intercomparisons in the UK

    International Nuclear Information System (INIS)

    The results of two recent (1989 and 1990) nationwide radioactivity-measurement intercomparisons covering a range of pure ?- and ?/?-emitting radionuclides are presented. Over fifty laboratories took part in the first exercise and, in general, the results were satisfactory although most laboratories confined themselves to ?-ray measurements only. There were some areas of concern, notably decay-scheme data, statements of uncertainty and cascade-summing effects. A follow-up meeting was held to discuss these points with the participants. As a result of this meeting, a second exercise was held, covering a different range of nuclides at lower-activity levels and seeking to discover how participants had improved their procedures in the light of the results from the first exercise. The overall results of the two exercises are reviewed in the light of i) UK radioactivity-monitoring arrangements and ii) the National Measurement Accreditation Scheme (NAMAS). (author)

  6. 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)

  7. [Working environment measurement of radioactive substances].

    Science.gov (United States)

    Kunugita, Naoki

    2007-12-01

    The control of the working environment is one of the most important duties in any working place to prevent occupational disease. In Japan, in the case of the controlled area using unsealed radioisotopes, the measurement of the concentration of airborne radioactive substances should be carried out under the regulations of the "Industrial Safety and Health Law" and the "Ordinance on Prevention of Ionizing Radiation Hazards". Many reports showed that the results of regular working environment measurements of radioactive substances were about background levels. Safe working environments are sufficiently guaranteed by a suitable estimation and handling under the strict regulation by the "Laws Concerning the Prevention from Radiation Hazards Due to Radioisotopes and Others". The regulation by "Ordinance on Prevention of Ionizing Radiation Hazards" would be relaxed in the field of education and research, which use very low quantities of radioactive substances, in ways such as estimation by calculation in place of the actual measurement, decrease of the number of monthly measurements, and measurement exemption for low levels of isotopes. PMID:18170964

  8. ATLAS ALFA—measuring absolute luminosity with scintillating fibres

    CERN Document Server

    Franz, S

    2009-01-01

    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 restric...

  9. INTERPRETATION OF THE ARCADE 2 ABSOLUTE SKY BRIGHTNESS MEASUREMENT

    International Nuclear Information System (INIS)

    We use absolutely calibrated data between 3 and 90 GHz from the 2006 balloon flight of the ARCADE 2 instrument, along with previous measurements at other frequencies, to constrain models of extragalactic emission. Such emission is a combination of the cosmic microwave background (CMB) monopole, Galactic foreground emission, the integrated contribution of radio emission from external galaxies, any spectral distortions present in the CMB, and any other extragalactic source. After removal of estimates of foreground emission from our own Galaxy, and an estimated contribution of external galaxies, we present fits to a combination of the flat-spectrum CMB and potential spectral distortions in the CMB. We find 2? upper limits to CMB spectral distortions of ? -4 and |Yff| -4. We also find a significant detection of a residual signal beyond that, which can be explained by the CMB plus the integrated radio emission from galaxies estimated from existing surveys. This residual signal may be due to an underestimated galactic foreground contribution, an unaccounted for contribution of a background of radio sources, or some combination of both. The residual signal is consistent with emission in the form of a power law with amplitude 18.4 ± 2.1 K at 0.31 GHz and a spectral index of -2.57 ± 0.05.

  10. 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.)

  11. 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

  12. Accreditation of laboratories measuring environmental radioactivity

    International Nuclear Information System (INIS)

    The radiological state of our environment is a strong concern for the public. The measurement of the radioactivity is an answer to this concern. The French National Network for the Measurement of Environmental Radioactivity (www.mesure-radioactivite.fr.) centralizes all the results of measurements of radioactivity in the environment on the national territory. The web-site provide an easy access to the results. Nevertheless it is needed to ensure the quality of the results obtained by the laboratories before reporting them to the web-site. A new laboratory approval system was created through an ASN decision (decision no 2008-DC-0099 of 29 april 2008), taking into account the new prerogatives granted to ASN by Act of 13 june 2006 and the modification of Public Heath Code towards the protection of individuals against the risks arising from ionising radiations in november 2007. This paper presents this new regulation by specifying the nature of the laboratories concerned and the field of approval with more than forty different kinds of approval, relating to all the environmental compartments and various radionuclide measurements (alpha, beta or gamma emitters). It also details the procedure of approval which in particular include the conformity of the practices of the laboratory to the requirements of standard ISO/CEI 17025 and the regular participation to intercomparison tests organised by IRSN. It draws up the assessment of the laboratories approved on 1 January 2010 anlaboratories approved on 1 January 2010 and analyzes the distribution of approvals according to the statute of laboratories, the measurement categories and the nature of the measured environmental samples. (author)

  13. 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.)

  14. Cross section measurements on radioactive samples

    International Nuclear Information System (INIS)

    We have developed a system over the past few years at the Manuel Lujan, Jr. Neutron Scattering Center (LANSCE) for making (n,p) and (n,?) measurements on (mainly) radioactive nuclei. Measurements have included 7Be(n,p)7Li, 14N(n,p)14C, 17O(n,?)14C, 22Na(n,p)22Ne, 22Na(n,?)19F, 35Cl(n,p)35S and 36Cl(n,p)36S. The major basic physics motivation for these measurements has been the nuclear astrophysics to be learned. Currently, we are assembling a 4? detector of barium fluoride (BaF2) for making (n,?) measurements on radioactive nuclei with relatively short half lives. Once operational, this new detector should allow us to expand our measurements to many more nuclei, and to a broader range of nuclear physics and nuclear astrophysics issues addressed. Results of recent measurements are given and future plans are discussed. 38 refs., 2 figs

  15. Airborne radioactivity measurements from the Chernobyl plume

    International Nuclear Information System (INIS)

    Airborne gamma-ray measurements were made aboard the Pacific Northwest Laboratory DC-3 and the National Oceanic and Atmospheric Administration King Air research aircraft before and during the first passage of the Chernobyl radioactive cloud over the west coast of the North American continent. Measurements were made from Anchorage, Alaska south to Reno, Nevada. Calculated trajectories were used to estimate the location of the Chernobyl plume. The ratios of the observed volatile radionuclides (131I and 134Cs normalized to 137Cs) agreed with the reported discharge ratio. (author) 6 refs.; 3 tabs

  16. 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.

  17. Measurement of the one-way speed of light and the Earth's absolute velocity

    International Nuclear Information System (INIS)

    A simple variant of the rotating axle experiment is described, with the help of which the Earth's absolute velocity can be measured. The accuracy achieved has not permitted to register the effect of absolute motion. With this experiment the one-way speed of light has been measured with an accuracy of 10%. (Auth.)

  18. Accurate absolute measurement of trapped Cs atoms in a MOT

    Scientific Electronic Library Online (English)

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

    2007-10-01

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

  19. 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

  20. An absolute cavity pyrgeometer to measure the absolute outdoor longwave irradiance with traceability to international system of units, SI

    Science.gov (United States)

    Reda, Ibrahim; Zeng, Jinan; Scheuch, Jonathan; Hanssen, Leonard; Wilthan, Boris; Myers, Daryl; Stoffel, Tom

    2012-03-01

    This article describes a method of measuring the absolute outdoor longwave irradiance using an absolute cavity pyrgeometer (ACP), U.S. Patent application no. 13/049, 275. The ACP consists of domeless thermopile pyrgeometer, gold-plated concentrator, temperature controller, and data acquisition. The dome was removed from the pyrgeometer to remove errors associated with dome transmittance and the dome correction factor. To avoid thermal convection and wind effect errors resulting from using a domeless thermopile, the gold-plated concentrator was placed above the thermopile. The concentrator is a dual compound parabolic concentrator (CPC) with 180° view angle to measure the outdoor incoming longwave irradiance from the atmosphere. The incoming irradiance is reflected from the specular gold surface of the CPC and concentrated on the 11 mm diameter of the pyrgeometer's blackened thermopile. The CPC's interior surface design and the resulting cavitation result in a throughput value that was characterized by the National Institute of Standards and Technology. The ACP was installed horizontally outdoor on an aluminum plate connected to the temperature controller to control the pyrgeometer's case temperature. The responsivity of the pyrgeometer's thermopile detector was determined by lowering the case temperature and calculating the rate of change of the thermopile output voltage versus the changing net irradiance. The responsivity is then used to calculate the absolute atmospheric longwave irradiance with an uncertainty estimate (U95) of ±3.96 W m-2 with traceability to the International System of Units, SI. The measured irradiance was compared with the irradiance measured by two pyrgeometers calibrated by the World Radiation Center with traceability to the Interim World Infrared Standard Group, WISG. A total of 408 readings were collected over three different 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, with a standard deviation of ±0.7 W m-2. These results suggest that the ACP design might be used for addressing the need to improve the international reference for broadband outdoor longwave irradiance measurements.

  1. Measurement of Radioactivity in the Human Body

    International Nuclear Information System (INIS)

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

  2. Present status and prospects of ultralow level radioactivity measurements (8). Summary of ultralow level radioactivity measurements series

    International Nuclear Information System (INIS)

    This report summarizes the ultralow level radioactivity measurements series from one to seven. High quality measurement data of environmental radioactivity is obtained by the ultralow level radioactivity measurements techniques. Therefore, the static treatment of the data becomes easy work. Non-proliferation monitoring is able to measure the trace artificial radioactivity nucleus by a small amount of sample using this method. Geochemistry, marine chemistry and space science is able to use radioactive nucleus as tracers by this method. An ultralow level background detector, data acquisition by list mode, sun peak problem, decrease of the background of liquid scintillation by the underground measurement, use of spent shielding materials, and future researches using ultralow level radioactivity measurements are stated. (S.Y.)

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Tagliati, S.; Rydh, A.

    2012-01-01

    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 {\\mu}g Pb superconducting crystal to demonstrate the newly opened capabilities. The sample is measured using a diff...

  5. 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

  6. Absolute configurations of spiroiminodihydantoin and allantoin stereoisomers: comparison of computed and measured electronic circular dichroism spectra.

    Science.gov (United States)

    Ding, Shuang; Jia, Lei; Durandin, Alexander; Crean, Conor; Kolbanovskiy, Alexander; Shafirovich, Vladimir; Broyde, Suse; Geacintov, Nicholas E

    2009-06-01

    The assignment of absolute configurations is of critical importance for understanding the biochemical processing of DNA lesions. The diastereomeric spiroiminodihydantoin (Sp) lesions are oxidation products of guanine and 8-oxo-7,8-dihydroguanine (8-oxoG), and the absolute configurations of the two diastereomers, Sp1 and Sp2, have been evaluated by experimental and computational optical rotatory dispersion (ORD) methods. In order to support our previous assignments by the ORD method, we calculated the electronic circular dichroism spectra (ECD) of the Sp stereoisomers. Comparison of the experimentally measured and computed ECD spectra indicates that Sp1 has (-)-S absolute configuration, while Sp2 has (+)-R absolute configuration. Thus, the S and R assignments, based on the ECD spectra of Sp1 and Sp2, are consistent with our previous assignments of absolute configurations. To further test the validity of this approach, we performed a proof-of-principle computation of the ECD and ORD of the R and S enantiomers of allantoin (similar in chemical composition to Sp) of known absolute configurations. The calculations provide the correct assignment of the absolute configurations of the allantoin enantiomers, indicating that the computational TDDFT approach is robust for identifying the absolute configurations of allantoins and probably the Sp stereoisomers, as has been shown previously for other organic molecules. PMID:19485408

  7. Quality control laboratories for measuring radioactivity

    International Nuclear Information System (INIS)

    In those laboratories involved in the measurement of radioactivity it is considered that a good determination requires, among other issues, and adequate monitoring of equipment performance and reagents and tracers. In this paper some of the parameters, of equipment performance are described together with some of the problems associated with their control and outlining possible solutions. Later, routine determinations are considered. For it is taken into account that an adequate control of the goodness of the results requires checking the whole measurement system, from sample reception to results delivery. In addition, the pros and cons of carrying out the enlargement of the control system so as to include management and performance of the laboratory as a whole in order to obtain an accreditation as external acknowledgement of well doing are discussed. Finally, this kind of acknowledgement, accreditation, is compared with the other kind of external acknowledgement of well doing: certification, establishing the former as adequate way of controlling not only the measurement process but also the management system. (Author). 15 refs.

  8. Radioactivity measurements using storage phosphor technology

    International Nuclear Information System (INIS)

    We propose to apply a recently developed charged particle radiation imaging concept in bio-medical research for fast, cost-effective characterization of radionuclides in contaminated sites and environmental samples. This concept utilizes sensors with storage photostimulable phosphor (SPP) technology as radiation detectors. They exhibit high sensitivity for all types of radiation and the response is linear over a wide dynamic range (>105), essential for quantitative analysis. These new sensors have an Active area of up to 35 cm x 43 cm in size and a spatial resolution as fine as 50 ?m. They offer considerable promise as large area detectors for fast characterization of radionuclides with an added ability to locate and identify hot spots. Tests with SPP sensors have found that a single alpha particle effect can be observed and an alpha field of 100 dpm/100 cm2 or a beta activity of 0.1 dpm/mm2 or gamma radiation of few ?R/hr can all be measured in minutes. Radioactive isotopes can further be identified by energy discrimination which is accomplished by placing different thicknesses of filter material in front of the sensor plate. For areas with possible neutron contamination, the sensors can be coupled to a neutron to charged particle converter screen, such as dysprosium foil to detect neutrons. Our study has shown that this approach can detect a neutron flux of 1 n/cm2s or lower, again with only minutes of exposure time. The with only minutes of exposure time. The utilization of these new sensors can significantly reduce the time and cost required for many site characterization and environmental monitoring tasks. The open-quotes exposureclose quotes time for mapping radioactivity in an environmental sample may be in terms of minutes and offer a positional resolution not obtainable with presently used counting equipment. The resultant digital image will lend itself to ready analysis

  9. Radioactivity measurements using storage phosphor technology

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-10-01

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

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

    Directory of Open Access Journals (Sweden)

    ANDREI ANTOHE

    2011-06-01

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

  11. Perfusion measurements with radioactively labelled microspheres

    International Nuclear Information System (INIS)

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

  12. Absolute beam emittance measurements at RHIC using ionization profile monitors

    Energy Technology Data Exchange (ETDEWEB)

    Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Connolly, R [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Summers, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-08-15

    In the past, comparisons between emittance measurements obtained using ionization profile monitors, Vernier scans (using as input the measured rates from the zero degree counters, or ZDCs), the polarimeters and the Schottky detectors evidenced significant variations of up to 100%. In this report we present studies of the RHIC ionization profile monitors (IPMs). After identifying and correcting for two systematic instrumental errors in the beam size measurements, we present experimental results showing that the remaining dominant error in beam emittance measurements at RHIC using the IPMs was imprecise knowledge of the local beta functions. After removal of the systematic errors and implementation of measured beta functions, precise emittance measurements result. Also, consistency between the emittances measured by the IPMs and those derived from the ZDCs was demonstrated.

  13. 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

  14. Technological Basis and Scientific Returns for Absolutely Accurate Measurements

    Science.gov (United States)

    Dykema, J. A.; Anderson, J.

    2011-12-01

    The 2006 NRC Decadal Survey fostered a new appreciation for societal objectives as a driving motivation for Earth science. Many high-priority societal objectives are dependent on predictions of weather and climate. These predictions are based on numerical models, which derive from approximate representations of well-founded physics and chemistry on space and timescales appropriate to global and regional prediction. These laws of chemistry and physics in turn have a well-defined quantitative relationship with physical measurement units, provided these measurement units are linked to international measurement standards that are the foundation of contemporary measurement science and standards for engineering and commerce. Without this linkage, measurements have an ambiguous relationship to scientific principles that introduces avoidable uncertainty in analyses, predictions, and improved understanding of the Earth system. Since the improvement of climate and weather prediction is fundamentally dependent on the improvement of the representation of physical processes, measurement systems that reduce the ambiguity between physical truth and observations represent an essential component of a national strategy for understanding and living with the Earth system. This paper examines the technological basis and potential science returns of sensors that make measurements that are quantitatively tied on-orbit to international measurement standards, and thus testable to systematic errors. This measurement strategy provides several distinct benefits. First, because of the quantitative relationship between these international measurement standards and fundamental physical constants, measurements of this type accurately capture the true physical and chemical behavior of the climate system and are not subject to adjustment due to excluded measurement physics or instrumental artifacts. In addition, such measurements can be reproduced by scientists anywhere in the world, at any time, by appeal to the scientific literature and protocols supported by the international community of measurement scientists. This link to the international measurement community provides an established link to a rigorous body of knowledge for the assessment of measurement uncertainty, which is crucial to societal objectives of a quantitative nature. Finally, because enhanced quantitative weather and climate prediction directly serve decision support structures that embody critical societal objectives, the credibility of these predictions is paramount. Since the foundation of credibility of any scientific theory is the underlying observational evidence, the link between these measurements and internationally recognized measurement standards is a critical component in the portfolio of Earth observing systems. Clearly measurements that are unerringly compatible with fundamental physical and chemical relationships offer distinct advantages for supporting improved prediction.

  15. 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)

  16. The study of absolute distance measurement based on the self-mixing interference in laser diode

    Science.gov (United States)

    Wang, Ting-ting; Zhang, Chuang

    2009-07-01

    In this work, an absolute distance measurement method based on the self-mixing interference is presented. The principles of the method used three-mirror cavity equivalent model are studied in this paper, and the mathematical model is given. Wavelength modulation of the laser beam is obtained by saw-tooth modulating the infection current of the laser diode. Absolute distance of the external target is determined by Fourier analysis method. The frequency of signal from PD is linearly dependent on absolute distance, but also affected by temperature and fluctuation of current source. A dual-path method which uses the reference technique for absolute distance measurement has been proposed. The theoretical analysis shows that the method can eliminate errors resulting from distance-independent variations in the setup. Accuracy and stability can be improved. Simulated results show that a resolution of +/-0.2mm can be achieved for absolute distance ranging from 250mm to 500mm. In the same measurement range, the resolution we obtained is better than other absolute distance measurement system proposed base on self-mixing interference.

  17. An Absolute Index (Ab-index) to Measure a Researcher’s Useful Contributions and Productivity

    OpenAIRE

    Biswal, Akshaya Kumar

    2013-01-01

    Bibliographic analysis has been a very powerful tool in evaluating the effective contributions of a researcher and determining his/her future research potential. The lack of an absolute quantification of the author’s scientific contributions by the existing measurement system hampers the decision-making process. In this paper, a new metric system, Absolute index (Ab-index), has been proposed that allows a more objective comparison of the contributions of a researcher. The Ab-index takes int...

  18. Laser-induced fluorescence measurements of absolute atomic densities: concepts and limitations

    International Nuclear Information System (INIS)

    The potential of laser-induced fluorescence spectroscopy of atoms is reviewed with emphasis on the determination of absolute densities. Examples of experiments with single-photon and two-photon excitation are presented. Calibration methods applicable with the different schemes are discussed. A new method is presented that has the potential to allow absolute measurement in plasmas of elevated pressure where collisional depletion of the excited state is present

  19. Absolute measurement of ? emitters with a 4 ? counter

    International Nuclear Information System (INIS)

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

  20. High-precision absolute distance and vibration measurement with frequency scanned interferometry

    International Nuclear Information System (INIS)

    We report high-precision absolute distance and vibration measurements performed with frequency scanned interferometry using a pair of single-mode optical fibers. Absolute distance was determined by counting the interference fringes produced while scanning the laser frequency. A high-finesse Fabry-Perot interferometer was used to determine frequency changes during scanning. Two multiple-distance-measurement analysis techniques were developed to improve distance precision and to extract the amplitude and frequency of vibrations. Under laboratory conditions, measurement precision of ?50 nm was achieved for absolute distances ranging from 0.1 to 0.7 m by use of the first multiple-distance-measurement technique. The second analysis technique has the capability to measure vibration frequencies ranging from 0.1 to 100 Hz with an amplitude as small as a few nanometers without a priori knowledge

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

    Science.gov (United States)

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

    2015-01-01

    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.

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

    Science.gov (United States)

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

    2015-01-01

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

  3. International conventions for measuring radioactivity of building materials

    International Nuclear Information System (INIS)

    In buildings, whether civil or industrial, natural radioactivity always occurs at different degrees in the materials (main building materials, decorative materials). Concerns on radioactivity from building materials is unavoidable for human living and developing. As a member of WTO, China's measuring method of radioactivity for building materials, including radionuclides limitation for building materials, hazard evaluation system etc, should keep accordance with the international rules and conventions. (author)

  4. Measurement of absolute bone blood flow by positron emission tomography

    International Nuclear Information System (INIS)

    A method of measuring bone blood flow has been developed using 18F sodium fluoride and positron emission tomography. The blood flow levels are in line with those obtained experimentally from microsphere embolisation. This investigative method could be applied to elucidate a number of clinical questions involving bone perfusion. (orig.)

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

    CERN Document Server

    Leviton, Douglas B; Kvamme, Todd

    2008-01-01

    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 ...

  6. Nuclide-specific measuring method for determination of radioactive contamination of food and drinking water

    International Nuclear Information System (INIS)

    The radioactivity measurable with the equipment explained (?-spectrometry using Ge detectors) is in the range 0.2 ?Ci to 1 mCi. Measuring times are below 15 min. The arrangement offers high variability and adaptation to specific conditions, variation of the distance between detector and sample together with a planary geometry of the detector making the ratios between distance and absolute sensitivity of the detector very simple. The dead time of the detector is kept below 15 p.c. by suitable variation of distances. Up to this dead time, the line width is constant. (orig./HP)

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

    International Nuclear Information System (INIS)

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

  8. Measurement time interval based on FPGA in NIM-3 absolute gravimeter

    Science.gov (United States)

    Wu, Shuqing; Li, Chunjian; Su, Duowu; Feng, Jinyang; Xu, Jinyi

    2015-02-01

    In order to perform gravity measurement with compact and portable instrument at several ten mGal accuracy level, a digital fringe signal processing method was proposed for the measurement time interval in a ballistic free-fall absolute gravimeter. This method based on the theory of digital phase-shift which was used in the SOPC system on a FPGA DE2 Electric Board and NIOS-II processor produced by Altera company. This method has been successfully used for the measurement of interference fringe numbers and time interval in NIM-3 ballistic free-fall absolute gravimeter.

  9. Absolute Oxygenation Metabolism Measurements Using Magnetic Resonance Imaging

    OpenAIRE

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

    2011-01-01

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

  10. 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)

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

    Directory of Open Access Journals (Sweden)

    Leeper R.J.

    2013-11-01

    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.

  12. Relative gravity measurement campaign during the 7th International Comparison of Absolute Gravimeters (2005).

    Czech Academy of Sciences Publication Activity Database

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

    2009-01-01

    Ro?. 46, ?. 3 (2009), s. 214-226. ISSN 0026-1394 Institutional research plan: CEZ:AV0Z30120515 Keywords : absolute gravity measurements * relative gravity measurements * ICAG Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 1.634, year: 2009

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

    CERN Document Server

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

    2013-01-01

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

  14. Sounding rocket measurement of the absolute solar EUV flux utilizing a silicon photodiode

    Science.gov (United States)

    Ogawa, H. S.; Mcmullin, D.; Judge, D. L.; Canfield, L. R.

    1990-01-01

    A newly developed stable and high quantum efficiency silicon photodiode was used to obtain an accurate measurement of the integrated absolute magnitude of the solar extreme UV photon flux in the spectral region between 50 and 800 A. The adjusted daily 10.7-cm solar radio flux and sunspot number were 168.4 and 121, respectively. The unattenuated absolute value of the solar EUV flux at 1 AU in the specified wavelength region was 6.81 x 10 to the 10th photons/sq cm per s. Based on a nominal probable error of 7 percent for National Institute of Standards and Technology detector efficiency measurements in the 50- to 500-A region (5 percent on longer wavelength measurements between 500 and 1216 A), and based on experimental errors associated with the present rocket instrumentation and analysis, a conservative total error estimate of about 14 percent is assigned to the absolute integral solar flux obtained.

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

    International Nuclear Information System (INIS)

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

  16. Absolute photoluminescence quantum efficiency measurement of light-emitting thin films

    International Nuclear Information System (INIS)

    We developed an integrated monochromatic excitation light source integrating sphere based detection system to accurately characterize the absolute photoluminescence quantum efficiency of commonly used polymer light emitting films without using a reference sample. Our methodology is similar to the method reported by de Mello et al. [Adv. Mater. 9, 230 (1997)] In this Note, we show that the absolute photoluminescence quantum efficiency might only be measured when an appropriate calibration of the spectral variation of the measurement system is done. This calibration is especially important when employing a short excitation wavelength (<400 nm) for common silicon-based detector

  17. Results of radioactivity measurements on foodstuffs in Romania

    International Nuclear Information System (INIS)

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

  18. Self-mixing interferometry based on a double-modulation technique for absolute distance measurement

    Science.gov (United States)

    Guo, Dongmei; Wang, Ming

    2007-03-01

    A new, to the best of our knowledge, method for the measurement of the absolute distance of a remote target based on the laser diode self-mixing interferometry is presented. A double-modulation technique is introduced to improve the measurement resolution. Wavelength modulation of the laser beam is obtained by modulating the injection current of the laser diode. Phase modulation of the laser beam is obtained by an electro-optic crystal in the external cavity. Absolute distance of the external target is determined by the Fourier analysis method. Theoretical analysis and numerical simulations are given. Experimental results show that a resolution of ±0.3 mm can be achieved for absolute distance ranging from 277 to 477 mm.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-03-15

    The leaflet of the German Atomforum e.V. on radioactivity describes the different radiations: alpha, beta, gamma and neutron radiation. The discussed measuring variables are Becquerel (activity) and Sievert (radiation doses). Radiation sources and radiation effects are shortly described.

  20. Measurement of metallothionein by radioactive silver saturation method

    International Nuclear Information System (INIS)

    Radioactive silver saturation method has been developed for measurement of metallothionein in tissues of animal. The results show that the relative affinities of metals for metallothionein in 0.5M glycine buffer at pH 8.5 is Ag+ > Cu2+ > Cd2+ > Hg2+ > Zn2+, and measurement of metallothionein in liver of rats induced by zinc using radioactive silver satruation method is sensitive and valid

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

    International Nuclear Information System (INIS)

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

  2. Absolute measurements of collisional ionization of xenon atoms in well-defined high Rydberg states

    International Nuclear Information System (INIS)

    Measurements of the absolute cross sections for Xe+ production in collisions betweeen xenon atoms in a single well-defined high Rydberg state vertical-barnf= and SF6 are reported and are approx.10-11 cm2 for 25 6 interaction, with the Xe+ ion core playing a minor role

  3. New absolute distance measurement technique with a self-mixing interferometer

    International Nuclear Information System (INIS)

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

  4. New absolute distance measurement technique with a self-mixing interferometer

    Science.gov (United States)

    Guo, Dongmei; Wang, Ming

    2007-07-01

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

  5. New absolute distance measurement technique with a self-mixing interferometer

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-15

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    Leviton, Douglas; Frey, Bradley

    2005-01-01

    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.

  8. Absolute Wavelength Calibration of the IDSII Spectrometer for Impurity Ion Velocity Measurements in the MST

    Science.gov (United States)

    Baltzer, M.; Craig, D.; den Hartog, D. J.; Nornberg, M. D.; MST Team

    2014-10-01

    The MST operates two Ion Doppler Spectrometers (IDS) for high time-resolution passive and active measurements of impurity ion emission. Absolutely calibrated measurements of flow are difficult because the spectrometers record data within 0.3 nm of the line of interest, and commercial calibration lamps do not produce lines in this narrow range . Four calibration methods were investigated. First, emission along the chord bisecting the poloidal plane was measured as it should have no time-averaged Doppler shift. Second, a calibrated CCD spectrometer and the IDSII were used to observe the same plasma from opposing sides so as to measure opposite Doppler shifts. The unshifted line is located halfway between the two opposing measurements. Third, the two fibers of the IDSI were positioned to take absolute flow measurements using opposing views. Substituting the IDSII for one of the IDSI fibers, absolute measurements of flow from the IDSI were used to calibrate the IDSII. Finally, an optical system was designed to filter an ultraviolet LED, providing a known wavelength source within the spectral range covered by the IDSII. The optical train is composed of an air-gapped etalon and fused silica lenses. The quality of calibration for each of these methods is analyzed and their results compared. Preliminary impurity ion velocity measurements are shown. This work has been supported by the US DOE and the NSF.

  9. A novel method for the absolute fluorescence yield measurement by AIRFLY

    International Nuclear Information System (INIS)

    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.

  10. Natural radioactivity measurements at the proposed nuclear power plant site

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    Mühlig, Christian; Bublitz, Simon; Paa, Wolfgang

    2011-05-01

    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.

  12. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

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

    CERN Document Server

    Lefeuvre, G; Gorodetzky, P; Patzak, T; Salin, P

    2007-01-01

    The nitrogen fluorescence induced in air is used to detect ultra-high energy cosmic rays 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 $\\pm$ 0.20 photons per meter when normalized to 760 mmHg, 15 degrees C 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 PhD thesis [32].

  15. High-precision Absolute Distance Measurements over a Long Range Based on Two Optoelectronic Oscillators

    CERN Document Server

    Yu, Jinlong; Miao, Wang; Zhu, Jigui; Sun, Bin; Wang, Wenrui; Hu, Hao

    2012-01-01

    Absolute distance measurement (ADM) over a long range has been studied intensely over the last several decades, due to its important applications in large-scale manufacturing and outer space explorations [1-5]. Traditional absolute distance measurements utilize detection of time-of-flight information, detection of phase shift, or a combination of the two [6-17]. In this paper, we present a novel scheme for high-precision ADM over a long range based on frequency detection by using two optoelectronic oscillators (OEO) to convert distance information to frequency information. By taking advantage of accumulative magnification theory, the absolute error of the measured distance is magnified by about 2*10E5 times, which makes the precision of the measured distance significantly improved. In our experiments, the maximum error is 1.5 um at the emulated ~6 km distance, including the drift error of about 1 um in the air path due to the change in environmental conditions. In addition, the measurable distance using this ...

  16. Subnanometer absolute displacement measurement using a frequency comb referenced dual resonance tracking Fabry-Perot interferometer.

    Science.gov (United States)

    Zhu, Minhao; Wei, Haoyun; Zhao, Shijie; Wu, Xuejian; Li, Yan

    2015-05-10

    Fabry-Perot (F-P) interferometry is a traceable high-resolution method for displacement metrology that has no nonlinearity. Compared with the single resonance tracking F-P interferometry, the dual resonance tracking (DRT) F-P interferometer system is able to realize tens of millimeters measurement range while maintaining the intrinsic high resolution. A DRT F-P system is thus developed for absolute displacement measurement in metrology applications. Two external cavity diode lasers (ECDLs) are simultaneously locked to two resonances of a high-finesse F-P cavity using the Pound-Drever-Hall locking scheme. The absolute optical frequencies of the locked ECDLs are measured using a reference diode laser, with the frequency stabilized and controlled by an optical frequency comb. The absolute cavity resonance order numbers are investigated. The measurement range is experimentally tested to achieve 20 mm, while the resolution reaches ?10??pm level, mainly limited by the mechanical stability of the F-P cavity. Compared with the measurement results from a self-developed displacement-angle heterodyne interferometer, the displacement residuals are within 10 nm in the range of 20 mm. This high-resolution interferometer may become a candidate for length metrology such as in Watt balance or Joule balance projects. PMID:25967521

  17. Temperature-dependent Absolute Refractive Index Measurements of Synthetic Fused Silica

    Science.gov (United States)

    Leviton, Douglas B.; Frey, Bradley J.

    2006-01-01

    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.

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

    Science.gov (United States)

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

    2014-05-01

    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.

  19. A system and methodologies for absolute QE measurements from the vacuum ultraviolet through the NIR

    CERN Document Server

    Jacquot, Blake C; Hoenk, Michael E; Greer, Frank; Jones, Todd J; Nikzad, Shouleh

    2011-01-01

    In this paper we present our system design and methodology for making absolute quantum efficiency (QE) measurements through the vacuum ultraviolet (VUV) and verify the system with delta-doped silicon CCDs. Delta-doped detectors provide an excellent platform to validate measurements through the VUV due to their enhanced UV response. The requirements for measuring QE through the VUV are more strenuous than measurements in the near UV and necessitate, among other things, the use of a vacuum monochromator, good dewar chamber vacuum to prevent on-chip condensation, and more stringent handling requirements.

  20. 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.)

  1. Color-coding and phase-shift method for absolute phase measurement

    Science.gov (United States)

    Chen, Xiangcheng; Lu, Chao; Ma, Mengchao; Mao, Xuesong; Mei, Tao

    2013-07-01

    In this paper, a novel color-coding method for absolute phase measurement is proposed. A three steps phase-shift algorithm was adopted to calculate the relative phase (wrapped phase) because of the least need of images. Color strips were used to mark each 2? phase-change period and three neighboring colors as a group were used as codewords to identify the fringe orders. With the two parts, relative phase and fringe orders, the absolute phase can be obtained directly. We selected five colors (black, red, green, blue, and white) to test our algorithm, and nearly 60 different codewords were embedded in one image. The fringe orders and the relative phase are calculated simultaneously, and this algorithm can circumvent the phase unwrapping process. Moreover, errors will not diffuse, because the relative phase and fringe orders are uncorrelated. Besides, no need of unwrapping processing will lead to high speed in 3D profile measurement. In addition, large object can be measured with high precision using this method owe to enormous codewords can be embedded in one color image. One experiment with a small object and a big complex object was designed to test the algorithm for separate objects, and experimental results showed the validity of our algorithm for absolute phase measurement.

  2. 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.

  3. Absolute beam-charge measurement for single-bunch electron beams

    International Nuclear Information System (INIS)

    The absolute beam charge of a single-bunch electron beam with a pulse width of 10 ps and that of a short-pulsed electron beam with a pulse width of 1 ns were measured with a Faraday cup in a beam test for the KEK B-Factory (KEKB) injector linac. It is strongly desired to obtain a precise beam-injection rate to the KEKB rings, and to estimate the amount of beam loss. A wall-current monitor was also recalibrated within an error of ±2%. This report describes the new results for an absolute beam-charge measurement for single-bunch and short-pulsed electron beams, and recalibration of the wall-current monitors in detail. (author)

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

    Directory of Open Access Journals (Sweden)

    Ruiz P. D.

    2010-06-01

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

  5. 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)

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

    OpenAIRE

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

    2011-01-01

    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 experime...

  7. 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.)

  8. 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

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

    CERN Document Server

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

    2013-01-01

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

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

    CERN Document Server

    Nagornyi, V D

    2014-01-01

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

  11. Absolute measurement of oxygen edge structure in the quantum efficiency of X-ray CCDs

    International Nuclear Information System (INIS)

    As part of the program to calibrate X-ray CCD detectors for the AXAF mission we have performed high-spectral resolution, absolute measurements of CCD quantum efficiency using the synchrotron radiation and grating monochromator facilities of the FM radiometry laboratory at BESSY. We present here detailed measurements of the absolute quantum efficiency in the spectral region surrounding the oxygen K absorption edge for both front- and back-illuminated MIT Lincoln Laboratory CCDs. The absolute scale of the measurements is established by reference to an Electrical Substitution Radiometer. Near-edge absorption structure produces variations as large as 40% in the detection efficiency of the front-illuminated detectors. We find structure at energies immediately below the K absorption edge which we attribute to resonant absorption in the oxide layers of the CCD gate structure. The amplitude of edge structures in the back-illuminated devices is, as expected, much smaller. Finally, we demonstrate that edge structure can be reliably detected in CCD response using an electron impact source and a grating monochromator

  12. Measurement of the absolute np scattering differential cross section at 194 MeV

    International Nuclear Information System (INIS)

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

  13. Absolute refinement of crystal structures by X-ray phase measurements.

    Science.gov (United States)

    Morelhão, Sérgio L; Amirkhanyan, Zohrab G; Remédios, Cláudio M R

    2015-05-01

    A pair of enantiomer crystals is used to demonstrate how X-ray phase measurements provide reliable information for absolute identification and improvement of atomic model structures. Reliable phase measurements are possible thanks to the existence of intervals of phase values that are clearly distinguishable beyond instrumental effects. Because of the high susceptibility of phase values to structural details, accurate model structures were necessary for succeeding with this demonstration. It shows a route for exploiting physical phase measurements in the crystallography of more complex crystals. PMID:25921497

  14. 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

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

    CERN Multimedia

    Barschel, C

    2013-01-01

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

  16. 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.)

  17. 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)

  18. Improvement of a new portable monitor for measuring radioactivity levels

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Jen-Chia Tsai

    2006-04-01

    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.

  20. 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)

  1. 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)

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

    Science.gov (United States)

    Madej, A A; Siemsen, K J

    1996-06-01

    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

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

    Science.gov (United States)

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

    2014-06-01

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

  4. IAEA-MEL's AQCS programme for marine radioactivity measurements

    International Nuclear Information System (INIS)

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

  5. Measurement of residual radioactivity in the facility being decommissioned

    International Nuclear Information System (INIS)

    After decommissioned, the site of a nuclear facility is necessary not to be contaminated with any radioactivity for site radioactive-free release. Major nuclides deposited on components, building floors, sites etc. are found to be 60Co, 137Cs and etc. Because the latter nuclides usually accompany 60Co, the detection nuclide characterizing contamination can be determined to be 60Co. The termination survey for the site release must be carried out on the condition that the residual radioactivity is a very low level, and the site is a very large area. In addition there is possibility that the detection of 60Co is disturbed by the background level due to 40K and other natural radioactivities. Therefore, the basis of the measuring system consists of several NaI detectors and electronic circuits mounted on a vehicle in order to enhance the efficiencies of detection and of measuring operation. Further, the position of measuring points will be determined by an auto-positioning apparatus. Our development program of the measuring system is going on and will be outlined in the presentation. (author)

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

    Science.gov (United States)

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

    2012-01-01

    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.

  7. Periods Detected During Analysis of Radioactivity Measurements Data

    OpenAIRE

    Parkhomov, A. G.

    2010-01-01

    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...

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

    Science.gov (United States)

    Tufan, M Çagatay; Disci, Tugba

    2013-01-01

    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

  9. 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)

  10. Measurement of radioactivity in agricultural products (1995-96)

    International Nuclear Information System (INIS)

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

  11. 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.)

  12. Reliable non-ambiguity range extension with dual-comb simultaneous operation in absolute distance measurements

    International Nuclear Information System (INIS)

    We report an absolute distance measurement scheme using two simultaneous optical frequency combs with different repetition rates for reliable non-ambiguity range extension. Since the non-ambiguity range extension is susceptible to distance drift during the repetition rate adjustment, pulse trains with two different repetition rates are coupled and directed simultaneously onto a target for coincident distance measurement. The simultaneous measurement avoids the process of adjusting the repetition rate and suppresses the influence of distance drift therein. The distances measured by the two repetition rates are distinguished by type II second harmonic generation. Target movement and atmospheric variation are made to imitate the distance drift, and experimental results show that the non-ambiguity range extension remains effective along the measurement. (paper)

  13. ROKO-Database of the environmental radioactivity measurements in Slovenia

    International Nuclear Information System (INIS)

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

  14. The research radioactive aerosol size distribution measurement software

    International Nuclear Information System (INIS)

    Based on screen diffusion battery of particle size distribution of the radioactive aerosol measuring system developed a measurement and analysis software, the software operating environment was the embedded ARM-based hardware system and embedded linux operating system. The software is developed by the open source package QT. System functions included the measurement process control, screen diffusion battery transmittance calculations, particle size distribution measurement, measurement data analysed by the EM algorithm and Twomey algorithms, particle size distribution showed, system communication and other functions. (authors)

  15. 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

  16. Measuring technique and facility for detecting radioactively irradiated organic substances

    International Nuclear Information System (INIS)

    Organic substances exposed to radioactive radiation, especially food and luxury food, are detected by measuring the intensity of chemoluminescence at a given, raised temperature and comparing it with the intensity of chemoluminescence of unirradiated samples. The measurements are carried out preferably at a temperature of 400C to 600C and between the 1st and 60th minute after starting heat-up. (orig.)

  17. Use of Statistics for Data Evaluation in Environmental Radioactivity Measurements

    International Nuclear Information System (INIS)

    Counting statistics will give a correction on environmental radioactivity measurement result. Statistics provides formulas to determine standard deviation (SB) and minimum detectable concentration (MDC) according to the Poisson distribution. Both formulas depend on the background count rate, counting time, counting efficiency, gamma intensity, and sample size. A long time background counting results in relatively low SB and MDC that can present relatively accurate measurement results. (author)

  18. Absolute Quantum Yields for HCO Production in the Photolysis of Aldehydes Measured by Cavity Ringdown Spectroscopy

    Science.gov (United States)

    Stark, H.; Stark, H.; Brown, S. S.; Brown, S. S.; Cox, R. A.; Ravishankara, A. R.; Ravishankara, A. R.; Ravishankara, A. R.

    2001-12-01

    Generation of most radicals in the atmosphere is initiated by photolytic processes. It is therefore important to know the efficiencies of the photolytic processes. The high sensitivity of cavity ringdown spectroscopy (CRDS) to detect certain free radicals with suitable absorption features offers a quantitative detection method for quantum yield measurements, especially for small quantum yields, say just a few percent. Because CRDS works at any pressure and temperature, it enables quantum yield measurements over the entire range of atmospheric conditions. Here we describe the first photolysis experiments carried out in our laboratory using a CRDS setup. We detected HCO radicals at 613.85 nm with a tunable dye laser and photolyzed aldehydes from 310-350 nm using a frequency doubled tunable dye laser. To derive absolute quantum yields, ? , we used the photolysis of chlorine in the presence of chlorine nitrate as an actinometer by measuring the NO3 produced from the very fast reaction of chlorine atoms with chlorine nitrate. Using the derived laser fluence we could calculate ? . In a different set of experiments we measured the absolute HCO cross section by comparing the absorption due to NO3 produced from the Cl + ClONO2 reaction with the HCO absorbance from the Cl + H2CO reaction under the same conditions. The NO3 cross section at the detection wavelength of 613.85 nm (2A"(0900) formyl radical, HCO, from propionaldehyde. Some preliminary data on HCO yield in chloral (Cl3CCHO) photolysis at 325 nm will also be presented.

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

    CERN Document Server

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

    2014-01-01

    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.

  20. Common mistakes associated with absolute full energy peak efficiency measurements using high pure germanium detectors

    International Nuclear Information System (INIS)

    The present work focuses on the uncertainties associated with absolute full energy peak efficiency (AFEPE) when measurements of calibration point sources conducted at various distances from two high pure germanium detectors (HPGe) from Ortec and Eurisys. A set consists of 11 point sources from Amersham were used. The measurements were performed at different source to detector distances. All the spectra were unfolded and analyzed using Emc plus MCA card from Silena. Full energy peak efficiency for each energy was then calculated using the well-know formula. The first approach was to fit the experimental data using least square fitting. Following that, a comparison between the experimental and calculated results was performed. The scattering data due to measurements of the multi-energetic sources specially when measurements carried out at very close distances from the detector were plotted and discussed.(author)

  1. Absolute Density Calibration Cell for Laser Induced Fluorescence Erosion Rate Measurements

    Science.gov (United States)

    Domonkos, Matthew T.; Stevens, Richard E.

    2001-01-01

    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.

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

    CERN Document Server

    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

    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.

  3. Long-range, high-precision absolute distance measurement based on two optoelectronic oscillators.

    Science.gov (United States)

    Wang, Ju; Yu, Jinlong; Miao, Wang; Sun, Bin; Jia, Shi; Wang, Wenrui; Wu, Qiong

    2014-08-01

    We demonstrate a scheme for long-range, high-precision absolute distance measurement based on frequency detection using two optoelectronic oscillators to convert distance information to frequency information. The two-oscillator design offers the unique advantage of self-referencing. By taking advantage of the accumulative magnification theory, the error of the measured distance is decreased by approximately 10? fold, which significantly improves the precision of the measured distance. In our experiments, the maximum error is ±1.5???m at an emulated distance of approximately 3.35 km, including a drift error of approximately 1 ?m in the air path due to the variation of environmental conditions. The highest relative measurement precision achieved in our current system is 4.5×10?¹?. PMID:25078190

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    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.

  6. Measurement of Absolute np Scattering Differential Cross Sections with a Tagged Intermediate-Energy Neutron Beam

    International Nuclear Information System (INIS)

    I report the results of a new measurement of np elastic scattering cross sections, aimed at resolving discrepancies in the database at intermediate energies and at providing a new, accurate standard for neutron-induced cross sections in this energy regime. The approach exploits a tagged neutron beam in a kinematically complete double-scattering experiment, keeping systematic errors in the absolute cross sections below +2%. The results are in very good agreement with previous partial-wave analyses of the database, and they deviate systematically from some other recent experimental results that were excluded from those partial wave analyses

  7. Measurement of absolute displacement by a double-modulation technique based on a Michelson interferometer.

    Science.gov (United States)

    Chang, L W; Chien, P Y; Lee, C T

    1999-05-01

    A novel method is presented for of measuring absolute displacement with a synthesized wavelength interferometer. The optical phase of the interferometer is simultaneously modulated with a frequency-modulated laser diode and optical path-length difference. The error signal originating from the intensity modulation of the source is eliminated by a signal processing circuit. In addition, a lock-in technique is used to demodulate the envelope of the interferometric signal. The displacement signal is derived by the self-mixing technique. PMID:18319864

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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)

  9. Measurements of the Absolute Branching Fractions of B±?K±Xcc¯

    Science.gov (United States)

    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.; Vetere, M. Lo; 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.; Diberder, F. Le; 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.; Lodovico, F. Di; 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.

    2006-02-01

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

  10. Absolute transition probabilities in the spectra of EU I and EU II. II - Line intensity measurements

    Science.gov (United States)

    Karner, C.; Meyer, G.; Traeger, F.; Zu Putlitz, G.

    1982-03-01

    The relative intensities of 27 optical transitions in the Eu II spectrum are measured, and the excited state lifetimes absolute oscillator strengths are computed. A grating monochromator is used to observe selectively the emitted lines in the wavelength region from 350-750 nm, and a tungsten ribbon lamp is used for the calibration of the spectral sensitivity of the detection system. Relative line intensity numerical values demonstrate intensity differences of up to a factor of 1000, with errors amounting to a total uncertainty of 6% for strong lines and 8% for weak lines. The oscillator strengths of the first europium ion justify a new analysis of the solar abundance of this element.

  11. Portable measuring equipment for radioactive contamination

    International Nuclear Information System (INIS)

    The measuring instrument is composed of a probe part with analyzing electronics and a large-area counter. The counter tube is replaceably mounted on the casing of the analyzing electronics. It also has two guide grooves opposite to one another in which the slide bars of a base part belonging to the probe part can be inserted. This basic member which may e.g. be fastened onto the wall of a laboratory room has coupler links on one side, which come into contact with corresponding elements on the probe part if this one is pushed over the base part. These are, among others, a power supply, a click-stop device keeping both parts together and a gas supply for the large-ared counter. Charging of the power supply accumulators of the probe part as well as purging of the counting tube is therefore made possible in this state of interconnection. The click-stop device essentially consists of a spring-borne stop ball and a saw-tooth shaped gliding surface running up the stop ball if the probe part is inserted then releasing it again promptly. (DG)

  12. Remote measurements of radioactivity distribution with BROKK robotic system - 16147

    International Nuclear Information System (INIS)

    Robotic system for the remote measurement of radioactivity in the reactor areas was developed. The BROKK robotic system replaces hand-held radiation measuring tools. The system consists of a collimated gamma detector, a standard gamma detector, color CCD video camera and searchlights, all mounted on a robotic platform (BROKK). The signals from the detectors are coupled with the video signals and are transferred to an operator's console via a radio channel or a cable. Operator works at a safe position. The video image of the object with imposed exposure dose rate from the detectors generates an image on the monitor screen, and the images are recorded for subsequent analysis. Preliminary work has started for the decommissioning of a research reactor at the RRC 'Kurchatov Institute'. Results of the remote radioactivity measurements with new system during radiation inspection waste storage of this reactor are presented and discussed. (authors)

  13. 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

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

    International Nuclear Information System (INIS)

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

  15. Measuring the absolute position of EELS ionisation edges in a TEM

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2011-12-01

    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).

  17. Measurement of radioactivity levels and assessment of radioactivity hazards of soil samples in Karaman, Turkey

    International Nuclear Information System (INIS)

    In this study, the levels of the natural and artificial radioactivity in soil samples collected from surrounding of Karaman in Turkey were measured. Activity concentrations of the concerned radionuclides were determined by gamma-ray spectrometry using a high-purity germanium detector with a relative efficiency of 40 % at 1.332 MeV. The results obtained for the 238U series (226Ra, 214Pb and 214Bi), 232Th series (228Ac), 40K and fission product 137Cs are discussed. To evaluate the radiological hazard of radioactivity in samples, the radium equivalent activity (Raeq), the absorbed dose rate (D), the annual effective dose and the external (Hex) and internal hazard index (Hin) were calculated and presented in comparison with the data collected from different areas in the world and Turkey. (authors)

  18. 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

  19. Radioactive targets for neutron-induced cross section measurements

    International Nuclear Information System (INIS)

    Measurements using radioactive targets are important for the determination of key reaction path ways associated with the synthesis of the elements in nuclear astrophysics (sprocess), advanced fuel cycle initiative (transmutation of radioactive waste), and stockpile stewardship. High precision capture cross-section measurements are needed to interpret observations, predict elemental or isotopical ratios, and unobserved abundances. There are two new detector systems that are presently being commissioned at Los Alamos National Laboratory for very precise measurements of (n,?) and (n,f) cross-sections using small quantities of radioactive samples. DANCE (Detector for Advanced Neutron-Capture Experiments), a 4 ? gamma array made up of 160 BaF2 detectors, is designed to measure neutron capture cross-sections of unstable nuclei in the low-energy range (thermal to ?500 keV). The high granularity and high detection efficiency of DANCE, combined with the high TOF-neutron flux available at the Lujan Center provides a versatile tool for measuring many important cross section data using radioactive and isotopically enriched targets of about 1 milligram. Another powerful instrument is the Lead-slowing down spectrometer (LSDS), which will enable the measurement of neutron-induced fission cross-section of U-235m and other short-lived actinides in a energy range from 1-200 keV with sample sizes down to 10 nanograms. Due to the short half-life of the U-235m isomer (T1/2 = 26 minutes), the samples must be rapidly and repeatedly extracted from its 239Pu parent. Since 239Pu is itself highly fissile, the separation must not only be rapid, but must also be of very high purity (the Pu must be removed from the U with a decontamination factor >1012). Once extracted and purified, the 235mU isomer would be electrodeposited on solar cells as a fission detector and placed within the LSDS for direct (n,f) cross section measurements. The production of radioactive targets of a few milligrams will be described as well as the containment for safe handling of these targets at the Lujan Center at LANSCE. To avoid any contamination, the targets are electrochemically fixed onto thin Ti foils and two foils are placed back to back to contain the radioactive material within. This target sandwich is placed in a cylinder made of aluminum with thin translucent windows made of Kapton. Actinides targets, such as 234,235,236,238U, 237Np, and 239Pu are prepared by electrodeposition or molecular plating techniques. Target thicknesses of 1-2 mg/cm2 with sizes of 1 cm2 or more have been made. Other targets will be fabricated from separation of irradiated isotopically enriched targets, such as 155Eu from 154Sm,171Tm from 170Er, and 147Pm from 146Nd, which has been irradiated in the high flux reactor at ILL, Grenoble. A radioactive sample isotope separator (RSIS) is in the process of being commissioned for the preparation of other radioactive targets. A brief summary of these experiments and the radioactive target preparation technique will be given.

  20. Measurement of the absolute wavefront curvature radius in a heterodyne interferometer.

    Science.gov (United States)

    Hechenblaikner, Gerald

    2010-09-01

    We present an analytical derivation of the coupling parameter relating the angle between two interfering beams in a heterodyne interferometer to the differential phase signals detected by a quadrant photodiode. This technique, also referred to as differential wavefront sensing, is commonly used in space-based gravitational wave detectors to determine the attitude of a test mass in one of the interferometer arms from the quadrant diode signals. Successive approximations to the analytical expression are made to simplify the investigation of parameter dependencies. Motivated by our findings, we propose what we believe to be a new measurement method to accurately determine the absolute wavefront curvature of a single measurement beam. We also investigate the change in the coupling parameter when the interferometer "test mirror" is moved from its nominal position, an effect which mediates the coupling of mirror displacement noise into differential phase measurements. PMID:20808419

  1. Measurement of the absolute wavefront curvature radius in a heterodyne interferometer

    CERN Document Server

    Hechenblaikner, Gerald

    2010-01-01

    We present an analytical derivation of the coupling parameter relating the angle between two interfering beams in a heterodyne interferometer to the differential phase-signals detected by a quadrant photo-diode. This technique, also referred to as Differential Wavefront Sensing (DWS), is commonly used in space-based gravitational wave detectors to determine the attitude of a test-mass in one of the interferometer arms from the quadrant diode signals. Successive approximations to the analytical expression are made to simplify the investigation of parameter dependencies. Motivated by our findings, we propose a new measurement method to accurately determine the absolute wave-front curvature of a single measurement beam. We also investigate the change in coupling parameter when the interferometer "test-mirror" is moved from its nominal position, an effect which mediates the coupling of mirror displacement noise into differential phase-measurements.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

    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.

  3. 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. (author)

  4. Superharp - a wire scanner with absolute position readout for beam energy measurement at CEBAF

    International Nuclear Information System (INIS)

    The CEBAF superharp is an upgraded beam wire scanner which provides absolute beam position readout using a shaft encoder. Superharps allow for high precision measurements of the beam's profile and position (?x similar 10 ?m). The Hall C endstation at CEBAF will use three pairs of superharps to perform beam energy measurements with 10-3 accuracy. The three pairs are installed at the beginning, the mid-point and the end of the Hall C arc beamline. Using superharps in conjunction with a dual sensor system: the direct current pick-up and the bremsstrahlung detectors, beam profile measurements can be obtained over a wide beam current range of 1 similar 200 ?A. (orig.)

  5. Quality assurance programmes for radioactivity measurements in nuclear medicine

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  7. Absolute wavelength measurement and fine structure determination in 7Li II

    International Nuclear Information System (INIS)

    The energy levels of two-electron atoms continue to provide rigorous tests of relativistic quantum theory, and of correlation effects within a multi-particle system. These interactions are determined perturbatively, with several approximations, and theoretical results often differ. It is critical to provide precise measurements of absolute wavelengths connecting these atomic energy levels to obtain a resolution of the precision of the different parts of such complex calculations. In this work, we report a high precision optical measurements in the 1s2s 3S - 1s2p 3P multiplet of Li II using fast-beam laser spectroscopy. A collinear interaction using both parallel and antiparallel laser and ion beams allows both for precise elimination of large Doppler shifts, and for a strong kinematic narrowing of the observed resonances, as compared with thermal beam experiments. The wavelengths of the observed resonance fluorescence radiation are determined by comparing them with simultaneously recorded saturated absorption profiles of molecular iodine hyperfine components. In turn, the absolute wavelengths of the iodine lines are obtained from precisely calibrated Fabry-Perot etalon fringes in a separate experiment. The final precision of the Li II wavelengths is 5 parts in 109, which is at a level of precision of 80 ppM of the QED corrections in the transition. 3 refs., 1 figs., 1 tab

  8. The new IMGC-02 transportable absolute gravimeter: measurement apparatus and applications in geophysics and volcanology

    Directory of Open Access Journals (Sweden)

    V. D?errico

    2008-06-01

    Full Text Available The research carried out at the Istituto Nazionale di Ricerca Metrologica (formerly Istituto di Metrologia «G. Colonnetti» aiming to develop a transportable ballistic absolute gravimeter ended with a new version of the instrument, called the IMGC-02. It uses laser interferometry to measure the symmetrical free rising and falling motion of a test mass in the gravity field. Providing the same accuracy achieved with previous versions, the instrumental improvements mainly concern size, weight, data processing algorithms and operational simplicity. An uncertainty of 9 ?Gal (1 ?Gal=1×10?8 m·s?2 can be achieved within a single observation session, lasting about 12 h, while the time series of several observation sessions show a reproducibility of 4 ?Gal. At this level, gravity measurements provide useful information in Geophysics and Volcanology. A wide set of dynamic phenomena, i.e. seismicity and volcanic activity, can produce temporal gravity changes, often quite small, with an amplitude ranging from a few to hundreds of microgals. Therefore the IMGC absolute gravimeter has been employed since 1986 in surveying the Italian active volcanoes. A brief history of the gravimeter and the description of the new apparatus, together with the main results of ongoing applications in Geophysics and Volcanology are presented.

  9. 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

  10. 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)

  11. Precision mass measurements of radioactive nuclei at JYFLTRAP

    CERN Document Server

    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

    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.

  12. 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

  13. 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

  14. 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

  15. Absolute choline concentration measured by quantitative proton MR spectroscopy correlates with cell density in meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Qiang [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan)]|[West China Hospital of Sichuan University, Huaxi MR Research Center, Department of Radiology, Chengdu (China); Shibata, Yasushi; Kawamura, Hiraku; Matsumura, Akira [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan); Isobe, Tomonori [Kitasato University, Department of Medical Technology, School of Allied Health Sciences, Minato, Tokyo (Japan); Anno, Izumi [University of Tsukuba, Department of Radiology, Institute of Clinical Medicine, Tsukuba, Ibaraki (Japan); Gong, Qi-Yong [West China Hospital of Sichuan University, Huaxi MR Research Center, Department of Radiology, Chengdu (China)]|[University of Liverpool, Division of Medical Imaging, Faculty of Medicine, Liverpool (United Kingdom)

    2009-01-15

    This study was aimed to investigate the relationship between quantitative proton magnetic resonance spectroscopy (1H-MRS) and pathological changes in meningioma. Twenty-two meningioma cases underwent single voxel 1H-MRS (point-resolved spectroscopy sequence, repetition time/echo time = 2,000 ms/68, 136, 272 ms). Absolute choline (Cho) concentration was calculated using tissue water as the internal reference and corrected according to intra-voxel cystic/necrotic parts. Pathological specimens were stained with MIB-1 antibody to measure cell density and proliferation index. Correlation analysis was performed between absolute Cho concentration and cell density and MIB-1 labeled proliferation index. Average Cho concentration of all meningiomas before correction was 2.95 {+-} 0.86 mmol/kg wet weight. It was increased to 3.23 {+-} 1.15 mmol/kg wet weight after correction. Average cell density of all meningiomas was 333 {+-} 119 cells/HPF, and average proliferation index was 2.93 {+-} 5.72%. A linear, positive correlation between cell density and Cho concentration was observed (r = 0.650, P = 0.001). After correction of Cho concentration, the correlation became more significant (r = 0.737, P < 0.001). However, no significant correlation between Cho concentration and proliferation index was found. There seemed to be a positive correlation trend after correction of Cho concentration but did not reach significant level. Absolute Cho concentration, especially Cho concentration corrected according to intra-voxel cystic/necrotic parts, reflects cell density of meningioma. (orig.)

  16. 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

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

    CERN Document Server

    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

    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.

  18. 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.

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-15

    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.

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

    Science.gov (United States)

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

    2013-12-01

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

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

    Science.gov (United States)

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

    2013-04-01

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

  3. 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.)

  4. Adaptive spatially resolving detector for the extreme ultraviolet with absolute measuring capability

    International Nuclear Information System (INIS)

    A spatially resolving detector for the extreme ultraviolet (XUV) and soft x-ray spectral region is presented. Principle of operation is conversion of XUV radiation to visible light by a scintillator crystal. Luminescence is detected using charge coupled device camera and imaging optics. Single layer and multilayer coatings are applied to match the system to different spectral regions of interest. Field of view and spatial resolution can be adapted to the application. Calibration of the system enables to absolutely measure in-band radiation flux on the scintillator. The setup is designed for the characterization and optimization of XUV sources and XUV optical systems. Measurements, carried out to characterize the focus in a soft x-ray microscope, are presented as an application example.

  5. Adaptive spatially resolving detector for the extreme ultraviolet with absolute measuring capability.

    Science.gov (United States)

    Benk, Markus; Bergmann, Klaus

    2009-03-01

    A spatially resolving detector for the extreme ultraviolet (XUV) and soft x-ray spectral region is presented. Principle of operation is conversion of XUV radiation to visible light by a scintillator crystal. Luminescence is detected using charge coupled device camera and imaging optics. Single layer and multilayer coatings are applied to match the system to different spectral regions of interest. Field of view and spatial resolution can be adapted to the application. Calibration of the system enables to absolutely measure in-band radiation flux on the scintillator. The setup is designed for the characterization and optimization of XUV sources and XUV optical systems. Measurements, carried out to characterize the focus in a soft x-ray microscope, are presented as an application example. PMID:19334913

  6. 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%.

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

    CERN Document Server

    Sekalski, S P; Sekalski, S P

    2004-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-01

    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.)

  9. 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)

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

    CERN Document Server

    Cavalier, Sophie

    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, ...

  11. Lifetime measurements using radioactive ion beams at intermediate energies and the Doppler shift method

    Energy Technology Data Exchange (ETDEWEB)

    Dewald, A.; Melon, B.; Pissulla, T.; Rother, W.; Fransen, C.; Moeller, O.; Zell, K.O.; Jolie, J. [IKP, Univ. zu Koeln (Germany); Petkov, P. [Bulg. Acad. of Science, INRNE, Solfia (Bulgaria); Starosta, K.; Przemyslaw, A.; Miller, D.; Chester, A.; Vaman, C.; Voss, P.; Gade, A.; Glasmacher, T.; Stolz, A.; Bazin, D.; Weisshaar, D. [NSCL, MSU, East Lansing (United States)

    2007-07-01

    Absolute transition probabilities are crucial quantities in nuclear structure physics. Therefore, it is important to establish Doppler shift (plunger) techniques also for the measurement of level lifetimes in radioactive ion beam experiments. After a first successful test of the Doppler Shift technique at intermediate energy (52MeV/u) with a stable {sup 124}Xe beam, a plunger has been built and used in two experiments, performed at the NSCL/MSU with the SEGA Ge-array and the S800 spectrometer. The aim of the first experiment was to investigate the plunger technique after a knock-out reaction using a radioactive {sup 65}Ge beam at 100 MeV/u for populating excited states in {sup 64}Ge. The second experiment aimed to measure the lifetimes of the first 2{sup +} states in {sup 110,114}Pd with the plunger technique after Coulomb excitation at beam energies of 54 MeV/u. First results of both experiments will be presented and discussed. (orig.)

  12. Quartz crystal microbalance measurements of absolute laser photodeposition rates: Application to 257-nm deposition from W(CO)6

    International Nuclear Information System (INIS)

    A quartz crystal microbalance has been used to measure absolute rates of laser-induced photochemical deposition processes in real time. A cw UV laser (257 nm) focused at normal incidence onto the microbalance crystal surface is used to induce deposition by photodecomposition of an organometallic vapor. An equation is derived to obtain the absolute mass of the deposit. The method is demonstrated for photodeposition from W(CO)6

  13. Spectroscopic determination of electrical conductivity in an MHD duct from absolute intensity measurements

    Science.gov (United States)

    Wang, S. Y.; Smith, J. M.

    1977-01-01

    Measurements of the electrical conductivity in the NASA Lewis cesium seeded, H2-O2 MHD duct made by applying a voltage across the channel from one end electrode to the other, measuring the current, and using the inner electrodes as probes to monitor the voltage distribution along the channel were found to be in good agreement with theory except at low combustion pressures and/or high ratios of seed/oxygen mass flows. To corroborate these measurements and to analyze the possibility of nonuniform seed injection as a cause of the above deviations, a spectroscopic investigation of the plasma conductivity was undertaken. Radial profiles of emission coefficient were obtained from measured transverse profiles of the absolute integrated intensity by Abel inversion. Radial profiles of electrical conductivity were then obtained under two different assumptions. In the first the Cs seed fraction is assumed uniform and equal to the measured flow rate at the time when the temperature and conductivity were obtained. In the second method the local temperature and pressure are taken to be those given by a one-dimensional channel calculation including heat transfer and friction. The results of the two methods are compared to the previously measured conductivity.

  14. 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)

  15. Measurement of radioactivity in Norway. Annual report 1997

    International Nuclear Information System (INIS)

    The Norwegian Institute for Air Research (NILU) is managing a radioactivity monitoring network commissioned by the Norwegian Pollution Control Authority (Statens forurensningstilsyn). By 1997 the network consists of 28 stations throughout the country, especially tight in Finnmark.In addition there is a station in Russia (Verhetnetulomski). The 29 surveillance stations consist of: 12 ionic chamber instruments, 6 stationary gamma spectrometers for surveillance, 12 part-time gamma spectrometers designed for nutritional radioactivity measurements in co-operation with the Norwegian Food Control Authority (Naeringsmiddeltilsynet), LORAKON. The joint venture with LORAKON uses the gamma spectrometers at the stations for nutritional control for surveillance when they are not active in nutritional radioactivity measurements. The spectrometer detector is taken out of the lead tower and placed in windows at the laboratories. Then the spectrometer is connected to a telecommunication modem. The NILU computer is calling regularly whether the spectrometer is connected or not and uses it immediately when connected. The stations have not registered values that can not be attributed to natural variations in the radiation level or technical irregularities in 1997

  16. GEMS: Underwater spectrometer for long-term radioactivity measurements

    Science.gov (United States)

    Sartini, Ludovica; Simeone, Francesco; Pani, Priscilla; Lo Bue, Nadia; Marinaro, Giuditta; Grubich, Andry; Lobko, Alexander; Etiope, Giuseppe; Capone, Antonio; Favali, Paolo; Gasparoni, Francesco; Bruni, Federico

    2011-01-01

    GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework for a development of a submarine telescope for neutrino detection (KM3NeT Design Study Project). The spectrometer is highly sensitive to gamma rays produced by 40K decays but it can detect other natural (e.g., 238U,232Th) and anthropogenic radio-nuclides (e.g., 137Cs). GEMS was firstly tested and calibrated in the laboratory using known sources and it was successfully deployed for a long-term (6 months) monitoring at a depth of 3200 m in the Ionian Sea (Capo Passero, offshore Eastern Sicily). The instrument recorded data for the whole deployment period within the expected specifications. This monitoring provided, for the first time, a continuous time-series of radioactivity in deep-sea.

  17. GEMS: Underwater spectrometer for long-term radioactivity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sartini, Ludovica, E-mail: ludovica.sartini@ingv.i [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Genoa University, Genoa (Italy); Simeone, Francesco; Pani, Priscilla [' Sapienza' University and Istituto Nazionale di Fisica Nucleare (INFN), Sect.Roma, Roma (Italy); Lo Bue, Nadia; Marinaro, Giuditta [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Grubich, Andry; Lobko, Alexander [Institute for Nuclear Problems (INP), Belarus State University, Minsk (Belarus); Etiope, Giuseppe [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Capone, Antonio [' Sapienza' University and Istituto Nazionale di Fisica Nucleare (INFN), Sect.Roma, Roma (Italy); Favali, Paolo [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Gasparoni, Francesco; Bruni, Federico [Tecnomare S.p.A., Venice (Italy)

    2011-01-21

    GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework for a development of a submarine telescope for neutrino detection (KM3NeT Design Study Project). The spectrometer is highly sensitive to gamma rays produced by {sup 40}K decays but it can detect other natural (e.g., {sup 238}U,{sup 232}Th) and anthropogenic radio-nuclides (e.g., {sup 137}Cs). GEMS was firstly tested and calibrated in the laboratory using known sources and it was successfully deployed for a long-term (6 months) monitoring at a depth of 3200 m in the Ionian Sea (Capo Passero, offshore Eastern Sicily). The instrument recorded data for the whole deployment period within the expected specifications. This monitoring provided, for the first time, a continuous time-series of radioactivity in deep-sea.

  18. GEMS: Underwater spectrometer for long-term radioactivity measurements

    International Nuclear Information System (INIS)

    GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework for a development of a submarine telescope for neutrino detection (KM3NeT Design Study Project). The spectrometer is highly sensitive to gamma rays produced by 40K decays but it can detect other natural (e.g., 238U,232Th) and anthropogenic radio-nuclides (e.g., 137Cs). GEMS was firstly tested and calibrated in the laboratory using known sources and it was successfully deployed for a long-term (6 months) monitoring at a depth of 3200 m in the Ionian Sea (Capo Passero, offshore Eastern Sicily). The instrument recorded data for the whole deployment period within the expected specifications. This monitoring provided, for the first time, a continuous time-series of radioactivity in deep-sea.

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

    CERN Document Server

    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

    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.

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

    International Nuclear Information System (INIS)

    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 3He spin filter and a relative transmission measurement technique. 3He 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

  1. 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)

  2. Development of radioactive methods for direct measurement of steel machinability

    International Nuclear Information System (INIS)

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

  3. Radioactivity measurement of ?-nuclides by small solid angle method

    International Nuclear Information System (INIS)

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

  4. Environmental radioactivity measurements at BNL following the Chernobyl accident

    International Nuclear Information System (INIS)

    Measurements are reported of the concentrations at Berkeley in Gloucestershire of radioactivity in the air, rainwater, tap water, soil, herbage and fresh vegetables for the period 29 April 1986 to 15 May 1986, following the Chernobyl Power Station accident. Data for up to 18 gamma emitting isotopes are reported, together with some limited actinide-in-air measurements. Deposition velocities are calculated and an assessment is presented of the sensitivity of the techniques employed. Some data are also included on the gaseous composition of the cloud and the isotope dependent dose rate from deposition. (author)

  5. 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

  6. 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

  7. National audit of radioactivity measurements in Nuclear Medicine Centres

    International Nuclear Information System (INIS)

    Routine activity measurements of radiopharmaceutical solutions in Nuclear Medicine Centres (NMC) are carried out with the help of radionuclide calibrators (RC). These solutions are either ingested or injected to the patient for diagnosis or therapy. However, for the realization of an optimized examination, the activity of these radiopharmaceuticals must be determined accurately before administering it to patients. The primary standards are maintained by Radiation Standards Section, Radiological Physics and Advisory Division. National audit programmes of Iodine -131 activity measurements with RCs are conducted biannually to establish traceability to national standards and to check the status of nuclear medicine practice followed at the NMC. The results of fifteenth audit of 131I activity measurements with RC are presented in this paper. Questionnaires were sent to two hundred and thirty three NMCs in-the country. One hundred and nine NMC's agreed for participation and accordingly, glass vials containing radioactive 131I solution of nominal activity of 100 MBq were procured from Board of Radiation and Isotope Technology, Mumbai. The radioactivity in each vial was determined with high pressure re-entrant gamma ionisation chamber (GIC), a secondary standard maintained by this laboratory. The sensitivity coefficient of GIC is traceable to the primary standard. The standardized radioactive solution of 131I in glass vial was sent to each participant. Measurements results were reported in the reporting form sent. This audit was conducted in four schedules in Jan 2013. One hundred and sixty six results were received from one hundred and nine participants as many participants took measurements on more than one isotope calibrator

  8. Absolute height measurement of specular surfaces with modified active fringe reflection photogrammetry

    Science.gov (United States)

    Ren, Hongyu; Jiang, Xiangqian; Gao, Feng; Zhang, Zonghua

    2014-07-01

    Deflectometric methods have been studied for more than a decade for slope measurement of specular freeform surfaces through utilization of the deformation of a sample pattern after reflection from a tested sample surface. Usually, these approaches require two-directional fringe patterns to be projected on a LCD screen or ground glass and require slope integration, which leads to some complexity for the whole measuring process. This paper proposes a new mathematical measurement model for measuring topography information of freeform specular surfaces, which integrates a virtual reference specular surface into the method of active fringe reflection photogrammetry and presents a straight-forward relation between height of the tested surface and phase signals. This method only requires one direction of horizontal or vertical sinusoidal fringe patterns to be projected from a LCD screen, resulting in a significant reduction in capture time over established methods. Assuming the whole system has been precalibrated during the measurement process, the fringe patterns are captured separately via the virtual reference and detected freeform surfaces by a CCD camera. The reference phase can be solved according to the spatial geometric relation between the LCD screen and the CCD camera. The captured phases can be unwrapped with a heterodyne technique and optimum frequency selection method. Based on this calculated unwrapped-phase and that proposed mathematical model, absolute height of the inspected surface can be computed. Simulated and experimental results show that this methodology can conveniently calculate topography information for freeform and structured specular surfaces without integration and reconstruction processes.

  9. 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)

  10. The Baryon Oscillation Spectroscopic Survey: Precision measurements of the absolute cosmic distance scale

    CERN Document Server

    Schlegel, David; Eisenstein, Daniel

    2009-01-01

    BOSS, the Baryon Oscillation Spectroscopic Survey, is a 5-year program to measure the absolute cosmic distance scale and expansion rate with percent-level precision at redshifts z<0.7 and z~2.5. BOSS uses the "standard ruler" provided by baryon acoustic oscillations (BAO). BOSS will achieve a near optimal measurement of the BAO scale at z<0.7, with a redshift survey of 1.5 million luminous galaxies. It will pioneer a new method of BAO measurement at high redshift, using the LyA forest to 160,000 QSOs in the redshift range 2.1measurement precision for angular diameter distance d_A is 1.0%, 1.0%, and 1.5% at z=0.35, 0.6, and 2.5, respectively, and the forecast precision for the Hubble parameter H(z) is 1.8%, 1.7%, and 1.2% at the same redshifts. These measurements will provide powerful constraints on the nature of dark energy and the curvature of space, complementing the constraints obtained from other probes. BOSS will also provide a superb data set for studying large- and smal...

  11. Low energy ? counts at the radioactivity measurement laboratory of Grenoble

    International Nuclear Information System (INIS)

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

  12. 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)

  13. Evaluation of the uncertainty of environmental measurements of radioactivity

    International Nuclear Information System (INIS)

    Results obtained by measurement of radioactivity have traditionally been associated with an expression of their uncertainty, based on the so-called counting statistics. This is calculated together with the actual result on the assumption that the number of counts observed has a Poisson distribution with equal mean and variance. Most of the nuclear scientific community has, therefore, assumed that it already complied with the latest ISO 17025 requirements. Counting statistics, however, express only the variability observed among repeated measurements of the same sample under the same counting conditions, which is equivalent to the term repeatability used in quantitative analysis. Many other sources of uncertainty need to be taken into account before a statement of the uncertainty of the actual result can be made. As the first link in the traceability chain calibration is always an important uncertainty component in any kind of measurement. For radioactivity measurements in particular counting geometry assumes the greatest importance, because it is often not possible to measure a standard and a control sample under exactly the same conditions. In the case of large samples there are additional uncertainty components associated with sample heterogeneity and its influence on self-absorption and counting efficiency. An uncertainty budget is prepared for existing data for 137Cs in Danish soil, which is shown to account adequately for all sources of uncertainty. (aquately for all sources of uncertainty. (author)

  14. 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

  15. Simple on-line method of measuring the absolute ionization efficiency of an ion source

    International Nuclear Information System (INIS)

    We report a new method of measuring the absolute ionization efficiency of an ion source, which is independent of gas flow rate fed to an ionizer and of the detection efficiency of the resulting ions. The method is based on the fact that when a pulsed alternating potential is applied between the ionizer and an electrode placed outside near its exit hole, ions stored inside the ionizer when the potential is repulsive for the ions, are flushed out as soon as it becomes attractive. It is shown that when the duty factor and repetition rate of the applied potential are properly chosen, the magnitude of this bunching effect can simply be expressed only by the ionization efficiency. Since its magnitude can quickly be evaluated, for example by observing the time dependence of the bunched ion current in an oscilloscope, it provides a simple and reliable way for on-line diagnostics of the source. ((orig.))

  16. 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)

  17. Absolute measurement of thermal neutron flux by using natural copper foil

    International Nuclear Information System (INIS)

    Up to the present, gold foil has been regarded as the best detector in thermal neutron flux measurements, since its absorption cross section is very large and induced isotope 198Au has a simple decay schema. In this paper, it is shown that the copper foil has the great advantage over most other elements including gold in reactor physics experiments. With the use of natural copper, no complicated correction for perturbation and decreasing of neutron field is necessary for determining absolute value of thermal neutron flux in wide range of reactor power, and more accurate result can be obtained by means of gamma-gamma coincidence technique instead of beta-gamma coincidence method. (author)

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

    Science.gov (United States)

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

    2004-09-01

    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.

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

    CERN Document Server

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

    2013-01-01

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

  20. Measurement of the Absolute Branching Fraction of D0 to K- pi+

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prudent, X.; Tisserand, V.; Zghiche, A.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Lopez, L.; Palano, A.; /Bari U.; Eigen, G.; Ofte, I.; Stugu, B.; Sun, L.; /Bergen U.; Abrams, G.S.; Battaglia, M.; Brown, D.N.; Button-Shafer, J.; /LBL, Berkeley

    2007-04-25

    The authors measure the absolute branching fraction for D{sup 0} {yields} K{sup -} {pi}{sup +} using partial reconstruction of {bar B}{sup 0} {yields} D*{sup +}X{ell}{sup -}{bar {nu}}{sub {ell}} decays, in which only the charged lepton and the pion from the decay D*{sup +} {yields} D{sup 0}{pi}{sup +} are used. Based on a data sample of 230 million B{bar B} pairs collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC, they obtain {Beta}(D{sup 0} {yields} K{sup -}{pi}{sup +}) = (4.007 {+-} 0.037 {+-} 0.070)%, where the first error is statistical and the second error is systematic.

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

    DEFF Research Database (Denmark)

    Menn, W.; Hof, M.

    1996-01-01

    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

  2. Simple on-line method of measuring the absolute ionization efficiency of an ion source

    International Nuclear Information System (INIS)

    We report a new method of measuring the absolute ionization efficiency of an ion source, which is independent of gas flow rate fed to an ionizer and of detection efficiency of the resulting ions. The method is based on the fact that when a pulsed alternate potential is applied between the ionizer and an electrode set outside near its exit hole, ions stored inside the ionizer while the potential is repulsive for the ions are flushed out as soon as it becomes attractive. It is shown that when the duty factor and repetition rate of the applied potential are properly chosen, the magnitude of this bunching effect can simply be expressed only by the ionization efficiency. Since its magnitude can quickly be evaluated, for example, by observing the time dependence of the bunched ion current in an oscilloscope, it provides a simple and reliable way for on-line diagnostics of the source. (author)

  3. An absolute index (Ab-index) to measure a researcher's useful contributions and productivity.

    Science.gov (United States)

    Biswal, Akshaya Kumar

    2013-01-01

    Bibliographic analysis has been a very powerful tool in evaluating the effective contributions of a researcher and determining his/her future research potential. The lack of an absolute quantification of the author's scientific contributions by the existing measurement system hampers the decision-making process. In this paper, a new metric system, Absolute index (Ab-index), has been proposed that allows a more objective comparison of the contributions of a researcher. The Ab-index takes into account the impact of research findings while keeping in mind the physical and intellectual contributions of the author(s) in accomplishing the task. The Ab-index and h-index were calculated for 10 highly cited geneticists and molecular biologist and 10 young researchers of biological sciences and compared for their relationship to the researchers input as a primary author. This is the first report of a measuring method clarifying the contributions of the first author, corresponding author, and other co-authors and the sharing of credit in a logical ratio. A java application has been developed for the easy calculation of the Ab-index. It can be used as a yardstick for comparing the credibility of different scientists competing for the same resources while the Productivity index (Pr-index), which is the rate of change in the Ab-index per year, can be used for comparing scientists of different age groups. The Ab-index has clear advantage over other popular metric systems in comparing scientific credibility of young scientists. The sum of the Ab-indices earned by individual researchers of an institute per year can be referred to as Pr-index of the institute. PMID:24391941

  4. Establishing radioactivity measurement capabilities for nuclear medicine in Member States

    International Nuclear Information System (INIS)

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

  5. Comparison of methods and achievable uncertainties for the relative and absolute measurement of photoluminescence quantum yields.

    Science.gov (United States)

    Würth, Christian; Grabolle, Markus; Pauli, Jutta; Spieles, Monika; Resch-Genger, Ute

    2011-05-01

    The photoluminescence quantum yield (?(f)) that presents a direct measure for the efficiency of the conversion of absorbed photons into emitted photons is one of the spectroscopic key parameters of functional fluorophores. It determines the suitability of such materials for applications in, for example, (bio)analysis, biosensing, and fluorescence imaging as well as as active components in optical devices. The reborn interest in accurate ?(f) measurements in conjunction with the controversial reliability of reported ?(f) values of many common organic dyes encouraged us to compare two relative and one absolute fluorometric method for the determination of the fluorescence quantum yields of quinine sulfate dihydrate, coumarin 153, fluorescein, rhodamine 6G, and rhodamine 101. The relative methods include the use of a chain of ?(f) transfer standards consisting of several "standard dye" versus "reference dye" pairs linked to a golden ?(f) standard that covers the ultraviolet and visible spectral region, and the use of different excitation wavelengths for standard and sample, respectively. Based upon these measurements and the calibration of the instruments employed, complete uncertainty budgets for the resulting ?(f) values are derived for each method, thereby providing evaluated standard operation procedures for ?(f) measurements and, simultaneously, a set of assessed ?(f) standards. PMID:21473570

  6. 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)

  7. Absolute measurement of the isotopic ratio of a water sample with very low deuterium content

    International Nuclear Information System (INIS)

    The presence of H3+ ions which are indistinguishable from HD+ ions presents the principal difficulty encountered in the measurement of isotopic ratios of water samples with very low deuterium contents using a mass spectrometer. Thus, when the sample contains no deuterium, the mass spectrometer does not indicate zero. By producing, in situ, from the sample to be measured, water vapor with an isotopic ratio very close to zero using a small distilling column, this difficulty is overcome. This column, its operating parameters, as well as the way in which the measurements are made are described. An arrangement is employed in which the isotopic ratios can be measured with a sensitivity better than 0.01 x 10-6. The method is applied to the determination of the isotopic ratios of three low deuterium content water samples. The results obtained permit one to assign to the sample with the lowest deuterium content an absolute value equal to 1.71 ± 0.03 ppm. This water sample is a primary standard from which is determined the isotopic ratio of a natural water sample which serves as the laboratory standard. (author)

  8. 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.)

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

    International Nuclear Information System (INIS)

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

  10. Direct and absolute measurements of average fission neutron yield from uranium-235 and californium-252

    International Nuclear Information System (INIS)

    A recent survey by the IAEA has shown that significant discrepancies exist amongst absolute values of ?-bar and ?f. For ?-bar (235U) only one measurement, made in 1958 with a quoted precision of 1.5%, is considered independent, and the Westcott group reports that the original value has been lowered so that it is now 2.5% below the recommended least-squares average. There are four accepted values for ?-bar (252Cf), one of which is also about 2.5% lower than the least-squares fit; another is 1.6% lower, while the average of all measurements is 1% below the recommended values derived from the multiparameter fit. A similar situation exists with regard to 2200-m/s fission cross-sections, wherein the discrepancies far exceed the precision quoted for each experiment. Since these measurements represent the cornerstone of a strongly interrelated structure of nuclear data utilized in reactor physics, it is important that they be independently and accurately evaluated, despite the fact that there exists strong confidence in ?a, ?, and ? values which provide an overdetermined set of parameters. The experiment reported in this present paper has been designed to circumvent certain plausible systematic errors which may be responsible for the discrepancies. The total neutron yield has been measured for thermal neutron fission of 235U and also independently for 252Cf with an improved manganese bath apparatus. Evaroved manganese bath apparatus. Evaluation of possible error sources has led to the adoption of a sequence of precision techniques subjected to extensive verification. The neutron yield of a fission counter was determined with the manganese bath; the accuracy of the bath system was independently corroborated with 0.7% precision against the United States National Bureau of Standards secondary neutron source. Absolute beta-gamma and relative gamma-gamma coincidence techniques are important facets of this calibration. The fission rate of the fission counter was found in a separate prompt fission-neutron coincidence experiment, borrowing well-established methods from beta-gamma coincidence work. In the course of this calibration it was discovered that angular anisotropy in fission neutron emission is much more a problem than universally realized: it is possible that some of the discrepancies in reported ?-bar and ?f measurements result from discounting this correction too readily. This conclusion is supported with a series of angular traverses and, in the final analysis, by the contemporary ?-bar results reported in this paper. (author)

  11. Radioactivity measurement of single microparticles using an electrodynamic balance

    International Nuclear Information System (INIS)

    A new technique to detect and measure radioactivity in individual microparticles has been investigated. A single charged microdroplet was suspended in the path of a He-Ne laser by the superposed ac and dc electric fields of an electrodynamic balance (EDB). The droplet size was accurately determined from light scattering data using Mie theory, which enabled the charge on the drop to be calculated. When a radioactive material, 14C dibutylphthalate (DBP) was present within the drop or on the walls of the EDB chamber, partial ionization of the gas inside the chamber occurred, and the suspended drop lost charge due to scavenging of oppositely charged ions. The droplet charge loss provided a measure of the radioactivity present. The interpretation of charge-loss data and the effect of operating parameters on the performance of the device were investigated experimentally and theoretically. The sensitivity of the technique was investigated by making known additions of 14C DBP to the center of the bottom electrode of the EDB chamber. With a bihyperbolidal EDB, activity levels as low as 120 picocuries (pCi) were detected against a high background contamination. Using an uncontaminated EDB of a new design, the double-ring EDB, an addition of 20 pCi was easily measured. The performance of the bihyperbolidal EDB was theoretically evaluated by modeling the ion generation and transport by electric fields inside the chamber, and the calculated charge loss rates ber, and the calculated charge loss rates were comparable to experimental results. Activity levels near 1 pCi inside a suspended microparticle should be detectable

  12. ? radioactive aerosol's measurement and analysis in an area

    International Nuclear Information System (INIS)

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

  13. Direct measurements of neutron capture on radioactive isotopes

    CERN Document Server

    Couture, A

    2009-01-01

    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.

  14. On measurement of radioactive strontium in environmental materials

    International Nuclear Information System (INIS)

    As strontium 89 and 90 emit only beta rays, chemical procedure (separation and purification) or addition of tracer is inevitable before reliable data are obtained in the strontium radioactivity measurement of environmental materials. The reported values on the strontium contaminations at selected hot spot in Japan after Fukushima power plant accident teach us that the ratio of Sr-90/Cr-137 from soil samples mostly ?0.001 while some from other spots shows around 0.1 and even high value as near 1 from the seawater collected near the destroyed plant. Those who want to analyze the reported strontium data must take into consideration the above fact. (S. Ohno)

  15. 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.)

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

    International Nuclear Information System (INIS)

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

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

    CERN Document Server

    Knaack, K; Wittenburg, K

    2003-01-01

    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 ...

  18. Absolute cross sections measurement for the 12C + 12C system at astrophysically relevant energies

    International Nuclear Information System (INIS)

    The 12C + 12C fusion reaction has been studied in the center-of-mass energy range of 2.25 to 6.01 MeV. Through the detection of gamma rays from the first excited states of the residual nuclei 20Ne, 23Na and 23Mg, absolute cross sections for the 12C(12C,-bar ?), 12C(12C,-bar p) and 12C(12C,-bar n) reactions have been obtained. In this new measurement, the energy dependence of the S-factor is found to increase as the energy decreases below 3 MeV in the center of mass. This tendency was observed in previous measurements by Mazarakis et al., and has since then become a subject of controversy. In this work, where the cross sections are measured at even lower energies, we confirm the rise in the S-factor toward the energy region relevant for star evolution and nucleosynthesis calculations (Ec.m.=1-3 MeV)

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

    International Nuclear Information System (INIS)

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

  20. Measurement of indoor radon and natural/fall out radioactivity

    International Nuclear Information System (INIS)

    Indoor radon and natural radioactivity measurement surveys were carried out in various parts of the Punjab, Khyber Pakhtoonkha, FATA, Azad Jammu and Kashmir and Gilgit Baltistan using CR-39 based radon detectors. The annual effective dose, mean effective dose and exhalation rate were calculated for the general public. Indoor radon activity concentrations in the surveyed houses ranged from 12 +- 5 to 169 +- 9 Bq m/sup -3/ with an overall average value of 57 +- 30 Bq m/sup -3/ which is more than the world average of 40 Bq m/sup -3/. The indoor radon levels were maximum in winter and minimum during summer season and were within the recommended limits. Besides indoor radon and natural radioactivity measurements, uranium contents were determined in samples of drinking water collected from natural springs of Hatian Bala using fission track technique. Except in a few cases, the measured uranium concentration was found within the safe limit of 30 gL/sup -1/. (Orig./A.B.)

  1. Absolute pair-production cross-section measurements in targets of Z = 26, 29, 50, 82, and 92 with 1.119-MeV photons

    International Nuclear Information System (INIS)

    Absolute cross sections for the production of electron-positron pairs by 1.119-MeV photons have been measured with targets of iron, copper, tin, lead, and uranium. An improved internal-source spectrometer was used which utilized two large intrinsic Ge detectors. The results are in excellent agreement with the exact numerical calculations of Tseng and Pratt for Z = 26, 29, and 50, and show a systematic departure of 13 and 19 % above the theoretical values for Z = 82 and 92, respectively. The present cross section at Z = 92 is lower than and slightly outside of the error limits from the results obtained with our older spectrometer. The present method has the definite advantage that the absolute activities of the radioactive sources need not be known. It also has the obvious advantages attributable to the high-energy resolution of the two intrinsic Ge detectors. A preliminary measurement in a lead target, using 1.0766-MeV ? rays, clearly shows that this technique can be extended to lower photon energies with resulting errors comparable to those at 1.119 MeV

  2. Optical measurement of absolute flatness with the deflectometric measurement systems at PTB

    International Nuclear Information System (INIS)

    Highly accurate flatness measurements are needed for synchrotron optics, optical flats, or optical mirrors. Recently, two new scanning deflectometric flatness measurement systems have been installed at the Physikalisch-Technische Bundesanstalt (PTB). The two systems (one system for horizontal and the other for vertical specimens) can measure specimens with sizes up to one metre with an expected uncertainty in the sub-nanometre range. In addition to the classical deflectometric procedure, also the 'extended shear angle difference (ESAD)' and the 'exact autocollimation deflectometric scanning (EADS)' procedures are implemented. The lateral resolution of scanning deflectometric techniques is limited by the aperture of the angle measurement system, usually an autocollimator with typical apertures of a few millimetres. With the EADS procedure, the specimen is scanned with an angular null instrument which has the potential to improve the lateral resolution down to the sub-millimetre region. A new concept and design of an appropriate angular null instrument are presented and discussed.

  3. A method for measuring the viscosity of radioactive waste glasses

    International Nuclear Information System (INIS)

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

  4. Some meteorological applications of radioactive fallout measurements in antarctic snows

    International Nuclear Information System (INIS)

    Radioactive fallout measurements, generally performed to determine average snow accumulation rates, can also be used to determine other meteorological information. The following results were obtained from measurements on the Antarctic ice sheet: (1) A strasospheric residence time of 1.5 years for radioisotopes such as 90Sr and 137Cs. (2) A value of approximatively 1 of the ratio phi between the concentration measured in the air (g/m3 STP) and the concentration determined in the snow (g/g), with extreme values of 0.5 and 5. (3) The dry fallout represents between 15 and 25% of the total deposition in the coastal regions and as much as 40 to 60% in the central zones. (4) A precipitation increase of 30% occurred after 1965 when compared with the decade 1955-1965

  5. Measurement of radioactive soil contamination from the air

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Barbiellini, 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.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cutini, S.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Do Couto E Silva, E.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Enoto, T.; Falletti, L.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Fortin, P.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gehrels, N.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guiriec, S.; Hadasch, D.; Hayashida, M.; Hays, E.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Johnson, T. J.; Kamae, T.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S.-H.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Naumann-Godo, M.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Ritz, S.; Rochester, L. S.; Sgrò, C.; Siskind, E. J.; Smith, P. D.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tosti, G.; Troja, E.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Zimmer, S.

    2012-01-01

    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.

  7. 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)

  8. Environmental radioactivity monitoring in Lower Saxonia in 1991 and 1992. Joint report of the Lower Saxonian environmental radioactivity measuring stations

    International Nuclear Information System (INIS)

    The updated joint report of the lower Saxonian measuring stations for environmental radioactivity is for the years 1991 and 1992 and serves the purpose of providing information to interested citizens regarding the results of measurements. Technical terms are explained in the annex. Monitoring for environmental radioactivity (including foodstuffs and drinking water) has been carried through in Germany since the beginning of the 60s, when environmental radioactivity increased globally because of nuclear testing at that time. Measurements are executed by institutions of the federal government and laender on behalt of the federal government. Furthermore, measurements are regularly carried through in the surroundings of nuclear installations. Results are collected and evaluated by the federal authorities and regularly published by the Federal minister for environment, nature protection and reactor safety in the government's annual reports on ''Environmental radioactivity and radiation exposure''. Experiences with transfrontier radioactive contamination in the wake of the Chernobyl reactor accident prompted the federal government to intensify and reorganize environmental radioactivity monitoring. For this, the precautionary radiation protection law (StrVG) of 1986 provides the legal basis. (orig./HP)

  9. 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)

  10. Determination of difficult to measure actinides in radioactive liquid waste

    International Nuclear Information System (INIS)

    In decommissioning of a nuclear facilities and radioactive waste treatment the activity of various radionuclides need to be measured for the waste characterization. Radiochemical separation of 241Am, 237Np and isotopes of plutonium was tested on model solution of evaporator concentrate sample for isolation of each of them for alpha-spectrometry analysis. This paper describes use of the molecular recognition technology product AnaLig(R)Pu-01 gel from IBC Advanced technologies, Inc. to effectively and selectively pre-concentrate, separate and recover difficult-to-measure actinides from model solution of evaporator concentrate samples which belong to the most difficult matrices to analyse. The method is suitable for analysing highly contaminated samples of radioactive waste in a relatively short time. For counting the alpha activity of 241Am, 239,240Pu, 238Pu and 237Np ORTEC 576A alpha-spectrometer equipped with ULTRATM ion implanted silicon detectors (600 mm2 active area) was used. The spectra were processed by using the Alpha-visionTM 32-bit emulation software from the EG and G ORTEC company. (authors)

  11. Quality assurance for radioactive measurement in nuclear medicine

    International Nuclear Information System (INIS)

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

  12. Absolute coverage measurement of adsorbed CO and D2 on platinum

    International Nuclear Information System (INIS)

    Nuclear microanalysis, in conjunction with MeV 4He scattering, LEED, and Auger spectroscopy, is being applied to investigate the adsorption behaviour of various gases on monocrystalline platinum surfaces. Using an anodized Ta2O5 film of known thickness as the primary standard, we have calibrated the 16O(d,p1)17O reaction for analysing the surface coverage of oxygen in our UHV system with an absolute accuracy of +- 2%. Suitable secondary standards for calibrating the 12C(d,p)13C and D(3He,p)4He reactions have been prepared by cooling a clean metal target to 20 K and condensing on it a fairly thick (approx. 100 nm) film of either CO2 or D2O ice. The 16O(d,p1)17O reaction plus the Ta2O5 standard is then used to determine the absolute number of CO2 or D2O molecules (and hence the number of C or D atoms) in the frozen film to +- 3%. For saturation coverage of the Pt(100) surface with CO molecules at 185 K, preliminary values of (0.85 +- 0.06) x 1015O atoms cm-2 and (0.89 +- 0.04) x 1015 C atoms cm-2 have been obtained. Similar measurements on Pt(111) gave a saturation CO coverage corresponding to (0.69 +- 0.05)x 1015O atoms cm-2 and (0.79 +- 0.03) x 1015 C atoms cm-2. In both casesup> C atoms cm-2. In both cases, the 16O(d,p1)17O analysis gives a slightly smaller value than the 12C(d, p)13C result. In another series of runs, the D(3He,p)4He reaction has been used to measure the surface coverage of hydrogen on Pt(111). A 10 min exposure to 1.3 x 10-4 Pa of molecular D2 gas at 185 K produces a deuterium coverage of (1.10 +- 0.05) x 1015 atoms cm-2. (orig.)

  13. 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)

  14. Measuring of the radioactivity of liquid wastes and sewage sludge

    International Nuclear Information System (INIS)

    A mobile control station (MCS) and a central laboratory-based measuring system (CL) were developed for monitoring the level of the radioactivity of sewage and sludge in the public sewage system of Budapest (capital of Hungary). The gamma and beta activity of the samples can be measured in situ by MCS, as for alpha and soft beta rays the CL (with liquid-scintillation technique) is used. Gamma and beta isotopes with very low specific activity can be detected by thermoluminescent dosimeters located at in special sites in the sewage system. The quantity of the isotopes applied, especially sup(99m)Tc, has been increasing therefore an increasing local activity level must be taken into consideration for the sewage system of the capital. (Sz.J.)

  15. Natural radioactivity measurements of building materials in Baotou, China.

    Science.gov (United States)

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

    2012-12-01

    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

  16. Measurement of environmental radioactivity in Toki district, (2)

    International Nuclear Information System (INIS)

    Three and a half years have elapsed since the start of this joint research. At first, cosmic ray was measured with a Geiger counter made by ourselves, then strong radioactivity was found in soils and stones. In order to observe the natural environment in which we live from the viewpoint of radiation, the measuring instrument having better sensitivity and on which the effect of background is small was sought for. The main subject of this report is the progress during this period, accordingly, the circuit composition of a NaI scintillation counter, thermo-luminescent dosimeter and ionization chamber measurement are described. When the Tokitsu Elementary School was reconstructed from wooden structure to concrete structure, the exposure dose in the teacher's room doubled. One summer day, mutual comparison was carried out among the measurement with a Geiger counter, a NaI scintillator and a TLD using an ionization chamber as the reference. The features of various measuring instruments were clarified, and utilizing these results, the effect of the combined measurement can be obtained. (Kako, I.)

  17. Absolute ozone measurements for a low-energy pulsed plasma needle

    Science.gov (United States)

    Jiang, Chunqi; Puech, Vincent; Magne, Lionel; Jeanney, Pascal

    2009-10-01

    Applications of an atmospheric-pressure, nanosecond pulsed plasma jet for biomedical and dental disinfections have motivated numerous diagnostic studies in understanding of the underlying physics and chemistry during the plasma bactericidal processes. In this work, we present spectroscopic studies of a 3 cm long needle-like He-O2 plasma jet. Rotational temperature of the plasma jet was measured to be about 300 K with optical emission spectroscopy. Ozone, as a typical bactericidal species, was detected in the plasma. Optical absorption spectroscopy identifies the absolute concentration ozone to be 10^15 cm-3 when the plasma was powered with 140 ns, 6 kV pulses at 1.5 kHz. The production of ozone increases with pulse voltage and pulse repetition rate. O2 concentration in He was also found affecting the ozone generation. In addition, two-photon laser induced fluorescence radially resolves an ozone profile in a diameter of 1 mm produced by the plasma needle.

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

    CERN Document Server

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

    2005-01-01

    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...

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  1. 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

  2. Absolute Configurations of Spiroiminodihydantoin and Allantoin Stereoisomers: Comparison of Computed and Measured Electronic Circular Dichroism Spectra

    OpenAIRE

    Ding, Shuang; Jia, Lei; Durandin, Alexander; Crean, Conor; Kolbanovskiy, Alexander; Shafirovich, Vladimir; Broyde, Suse; Geacintov, Nicholas E.

    2009-01-01

    The assignment of absolute configurations is of critical importance for understanding the biochemical processing of DNA lesions. The diastereomeric spiroiminodihydantoin (Sp) lesions are oxidation products of guanine and 8-oxo-7,8-dihydroguanine (8-oxoG), and the absolute configurations of the two diastereomers, Sp1 and Sp2, have been evaluated by experimental and computational optical rotatory dispersion (ORD) methods. In order to support our previous assignments by the ORD method, we calcul...

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

    Science.gov (United States)

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

    1992-01-01

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

  4. Practice and experience in traceability of radioactivity measurements of environmental samples

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  6. Evaluation of the uncertainty of environmental measurements of radioactivity

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Huisman Martijn

    2007-10-01

    Full Text Available Abstract Background As reducing socio-economic inequalities in health is an important public health objective, monitoring of these inequalities is an important public health task. The specific inequality measure used can influence the conclusions drawn, and there is no consensus on which measure is most meaningful. The key issue raising most debate is whether to use relative or absolute inequality measures. Our paper aims to inform this debate and develop recommendations for monitoring health inequalities on the basis of empirical analyses for a broad range of developing countries. Methods Wealth-group specific data on under-5 mortality, immunisation coverage, antenatal and delivery care for 43 countries were obtained from the Demographic and Health Surveys. These data were used to describe the association between the overall level of these outcomes on the one hand, and relative and absolute poor-rich inequalities in these outcomes on the other. Results We demonstrate that the values that the absolute and relative inequality measures can take are bound by mathematical ceilings. Yet, even where these ceilings do not play a role, the magnitude of inequality is correlated with the overall level of the outcome. The observed tendencies are, however, not necessities. There are countries with low mortality levels and low relative inequalities. Also absolute inequalities showed variation at most overall levels. Conclusion Our study shows that both absolute and relative inequality measures can be meaningful for monitoring inequalities, provided that the overall level of the outcome is taken into account. Suggestions are given on how to do this. In addition, our paper presents data that can be used for benchmarking of inequalities in the field of maternal and child health in low and middle-income countries.

  8. 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.

  9. Cross-Section Measurements with the Radioactive Isotope Accelerator (RIA)

    Energy Technology Data Exchange (ETDEWEB)

    Stoyer, M A; Moody, K J; Wild, J F; Patin, J B; Shaughnessy, D A; Stoyer, N J; Harris, L J

    2002-11-19

    RIA will produce beams of exotic nuclei of unprecedented luminosity. Preliminary studies of the feasibility of measuring cross-sections of interest to the science based stockpile stewardship (SBSS) program will be presented, and several experimental techniques will be discussed. Cross-section modeling attempts for the A = 95 mass region will be shown. In addition, several radioactive isotopes could be collected for target production or medical isotope purposes while the main in-beam experiments are running. The inclusion of a broad range mass analyzer (BRAMA) capability at RIA will enable more effective utilization of the facility, enabling the performance of multiple experiments at the same time. This option will be briefly discussed.

  10. Radioactivity measurement in spring waters of Cantabria, Spain

    International Nuclear Information System (INIS)

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

  11. Influence of radioactive filiation on measured release curves

    International Nuclear Information System (INIS)

    Perturbation of measured release curves of radioactive nuclei by the decay of precursor nuclei in the target is investigated. The target is described by a simple model taking into account the direct production of the nucleus of interest by the reaction but also allowing decay of the isobaric precursor to take place specifically during diffusion or effusion. Their respective contributions to the observed ion currents can be enough different to lead to uncorrect analysis of the experimental release curves. As an example we discuss release curves of the pairs of neutron-rich isotopes (Rbm86, 91Rb) and (Csm130, 139Cs) produced by proton-induced fission at the IRIS facility, Gatchina

  12. 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)

  13. Measurement of radioactivity of cerium-144 by the 4??-? coincidence parameter method

    International Nuclear Information System (INIS)

    A brief description on the measurement of radioactivity of cerium-144 by a 4??-? coincidence parameter method is presented. The result of measurement was compared with that of measurement of radioactivity of cerium-144 by 4??-? coincidence absorber method. The two results agree quiet well

  14. Considerations on the detection limit in measurements of low level radioactive samples

    International Nuclear Information System (INIS)

    In the framework of the coordinated research programme on ''The Problems of the Radioecology of the Danube River'' many problems were raised concerning the measurement of low level radioactivity concentration in the various environmental samples. The paper analyses the limits of these measurements and provides practical examples and conclusions on the relationship of radioactivity concentration and the time-length of measurements. (author)

  15. 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)

  16. 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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  19. Measurements of the Temperature of Plasmas in MHD Ducts and Combustion Chambers by Recording Absolute Spectral Line Intensities

    International Nuclear Information System (INIS)

    This work has been carried out under a collaboration agreement between the Institute of Nuclear Research, Swierk, Poland, and CEN de Saclay, France. The author discusses the theory of measuring the temperature of plasmas in combustion chambers and MHD ducts by recording the absolute intensities (AI) of spectral lines. The accuracy of the method and its suitability for measuring the temperature of plasmas in MHD ducts is analysed. The paper describes the experimental set-up, which consists of a combustion chamber and an MHD duct, and presents a schematic diagram for temperature measurements by the absolute line intensity method. The paper also describes how the accuracy of the method is checked by determining the normalized coefficient of emission of the recorded Na15890 Å and Na1 5896 Å line values. A schematic diagram is also given for measuring the surface temperature of electrodes in an MHD duct through the plasma by means of an optical pyrometer. The author presents the results of plasma temperature measurements made by the absolute line intensity method and the results of electrode surface temperature measurements for different regimes of combustion chamber operation. (author)

  20. Radioactivity measurement in Austria 1992 and 1993. Data and evaluation

    International Nuclear Information System (INIS)

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

  1. Measurements of neutron cross sections of radioactive waste nuclides

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-01-01

    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)

  2. 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.

  3. Measuring the absolute deuterium-tritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF.

    Science.gov (United States)

    Casey, D T; Frenje, J A; Gatu Johnson, M; Séguin, F H; Li, C K; Petrasso, R D; Glebov, V Yu; Katz, J; Knauer, J P; Meyerhofer, D D; Sangster, T C; Bionta, R M; Bleuel, D L; Döppner, T; Glenzer, S; Hartouni, E; Hatchett, S P; Le Pape, S; Ma, T; MacKinnon, A; McKernan, M A; Moran, M; Moses, E; Park, H-S; Ralph, J; Remington, B A; Smalyuk, V; Yeamans, C B; Kline, J; Kyrala, G; Chandler, G A; Leeper, R J; Ruiz, C L; Cooper, G W; Nelson, A J; Fletcher, K; Kilkenny, J; Farrell, M; Jasion, D; Paguio, R

    2012-10-01

    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. PMID:23126915

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

    Science.gov (United States)

    Merle, Cormic; Wick, Eric; Hayden, Joseph

    2011-01-01

    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.

  5. Measurements of radioactivity in Austria 1998, data and assessment

    International Nuclear Information System (INIS)

    In Austria an extensive program is realized for the purpose of large scale surveillance on radioactivity. On the one hand an Early Radiation Warning System with 336 gamma dose rate monitors and several partly nuclide specific air contamination monitors is operated by the Federal Chancellery. The data are automatically communicated to various authorities in real-time. On the other hand the radionuclide content of various media such as air, precipitation, surface water, foodstuffs etc. is monitored by periodic sampling and analysis in laboratories. In addition to this routine program special projects are carried out for investigation of specific media and to improve the knowledge of the time dependence respectively of regional aspects of the contamination situation. The inspection of the nuclear installations by the authorities concerning emissions and immissions is set up of two parts: inspection of the quality of the internal control by the operator and independent surveillance by examination of samples taken by the authority. In 1998 the average annual radiation exposure of the Austrian population amounted to about 4.6 mSv effective dose. The contributions dominating by far originate from natural and medical sources of radiation. In comparison with these, contributions from all other sources of radiation are extremely small. The average annual effective dose caused by natural radiation amounts to approximately 3.2 mSv. The inhalation of the radioactive noble gas radohalation of the radioactive noble gas radon and its short lived progeny in the mean contributes more than half to this exposure. Mainly because of different radon values considerable variations in natural radiation exposure do occur. There are regions with particular geological conditions where exposure levels by far exceed the average dose due to high radon values. Artificial radiation exposure is predominantly caused by the use of radioactive substances and of ionizing radiation in medical applications, in particular by X-ray diagnostics, leading on the average to approximately 1.3 mSv annually in the reporting period. By comparison, the dose to the Austrian population due to the effects of the reactor accident at Chernobyl amounting in 1998 to less than 0.02 mSv is small. The exposure as a result of the operation of the nuclear installations at the Austrian Research Centre Seibersdorf and at the Atomic Institute of the Austrian Universities in 1998 was negligible. Investigative measurements by the authorities of gaseous and liquid emissions and the internal surveillance by the operators show that maximum permissible levels were never exceeded. Also environmental monitoring in the surroundings could not detect any inadmissible high gamma dose rates or immissions. The artificial radionuclide content of air, precipitation and surface water in the reporting period was mainly caused by the Chernobyl accident and similarly low as in the previous years. In these media the values for caesium-137 - which nowadays is the only significant radionuclide left from the Chernobyl fallout - are only slightly higher than before the accident. However, in soils from certain regions much higher caesium-137 concentrations can be found than before the accident. Since in most agriculturally used soils radiocaesium is strongly fixed to clay minerals and thus is only marginally available for plant uptake, foodstuffs and agricultural products generally show only minor caesium-137 concentrations. In comparison, significantly higher values still can be found in some forest produce such as wild growing fungi and game. In semi-natural forest ecosystems the fixation of caesium is much less effective keeping it biologically available. Usually, fungi and game are not consumed in larger amounts. Therefore the dose to man caused by this path generally is small. (author)

  6. A measurement of the absolute neutron beam polarization produced by an optically-pumped $^{3}He$ spin filter

    CERN Document Server

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

    2002-01-01

    The capability of performing accurate 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 absolute accuracy of 0.3% in the neutron energy range from 40 meV to 10 eV using an optically-pumped polarized 3He spin filter and a relative transmission measurement technique. 3He 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.

  7. Fire protection measures in a repository for radioactive wastes

    International Nuclear Information System (INIS)

    For the operational phase of the planned Konrad repository for radioactive waste, 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 surface and underground facilities of the repository. Examples of the realization of fire protection measures in the surface facilities in order to prevent internal fire and the burning of a vehicle are given. As a consequence of the experience with fire events in mines, the burning of a vehicle during transport of the waste packages is the only fire event which leads to an activity release out of the waste packages. In the framework of the incident analysis the thermal influence on the waste packages resulting from the fire event described above has been determined with the aid of a load function in form of a temperature-time-function (model curve). The effects resulting from this function have been calculated. (orig.)

  8. 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

  9. 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.

  10. Measurement of gross beta radioactivity in high-level liquid waste

    International Nuclear Information System (INIS)

    Using beta plastic scintillation counter of low level background, gross beta radioactivity of twelve samples for high-level liquid waste is determined directly. Beta efficiency curves of plastic scintillation counter for four mass thickness are calibrated in advance. Determining gross beta radioactivity, gross efficiency of the scintillation counter for various energy beta ray is calculated via weighted mean method with the ratio of radioactivity for each nuclide. The ratio of radioactivity for nuclides which have gamma disintegration is determined in terms of the radioactivity measured by gamma spectrometer. The ratio of the radioactivity for 90Sr which has purity beta disintegration is calculated in terms of half life time approximation. The ratio of the radioactivity for 147Pm which also has purity disintegration is calculated by means of apparent cooling-time approximation. The uncertainty of results for the present work is about +-15%

  11. Measurements of radioactive and xenobiotic substances in the biosphere in the Netherlands 1982

    International Nuclear Information System (INIS)

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

  12. 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

  13. 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

  14. Resolution limit of the white-light interferometric sensor for absolute position measurement based on central fringe maximum identification

    International Nuclear Information System (INIS)

    In this paper a simple theoretical analysis together with an experimental verification of the analysis that provides an estimation of the resolution limit of the white-light interferometric sensor for absolute position measurement based on central fringe maximum identification is presented. The resolution better than 10 pm is obtained in the white-light interferometric sensing system where the signal-to-noise ratio was greater than 80 dB. (paper)

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

    OpenAIRE

    F. Ambrosino; A. Antonelli; Antonelli, M; Archilli, F.; Bacci, C; Beltrame, P.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C; Bocchetta, S.(Fysiska institutionen, Lunds universitet, Lund, Sweden); F. Bossi; Branchini, P.; Campana, P.; Capon, G.

    2008-01-01

    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}.

  16. 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)

  17. Absolutely calibrated, time-resolved measurements of soft x rays using transmission grating spectrometers at the Nike Laser Facility

    International Nuclear Information System (INIS)

    Accurate simulation of pellet implosions for direct drive inertial confinement fusion requires benchmarking the codes with experimental data. The Naval Research Laboratory (NRL) has begun to measure the absolute intensity of radiation from laser irradiated targets to provide critical information for the radiatively preheated pellet designs developed by the Nike laser group. Two main diagnostics for this effort are two spectrometers incorporating three detection systems. While both spectrometers use 2500 lines/mm transmission gratings, one instrument is coupled to a soft x-ray streak camera and the other is coupled to both an absolutely calibrated Si photodiode array and a charge coupled device (CCD) camera. Absolute calibration of spectrometer components has been undertaken at the National Synchrotron Light Source at Brookhaven National Laboratories. Currently, the system has been used to measure the spatially integrated soft x-ray flux as a function of target material, laser power, and laser spot size. A comparison between measured and calculated flux for Au and CH targets shows reasonable agreement to one-dimensional modeling for two laser power densities

  18. Chiral Cavity Ring-Down Absolute Measurement of Optical Rotation in Gases and Liquids with Signal Reversals

    Science.gov (United States)

    Bougas, Lykourgos; Katsoprinakis, G. E.; Rakitzis, T. P.

    2013-06-01

    We demonstrate the absolute measurement of optical rotation using a four-mirror cavity-ring-down polarimetric setup. A four-mirror bow-tie cavity allows counter-propagating laser beams, for which symmetry is broken with a longitudinal magnetic field acting upon an intracavity magneto-optic window (producing a Faraday rotation ?_{{F}}). A chiral sample is introduced in one arm of the cavity, producing a chiral rotation ?_{_{{C}}}. The different symmetry of the two rotations produces a total rotation of (?_{{F}} + ?_{_{{C}}}) for one laser beam, and (?_{{F}} + ?_{_{{C}}}) for the counter-propagating beam. These rotations produce a polarization beating in the cavity ring-down, of frequency ?_{_{{CW}}} and ?_{_{{CCW}}} for the clockwise and counter-clockwise beams, respectively. Analysis of the difference (?_{_{{CW}}}-?_{_{{CCW}}}) yields the chiral rotation angle ± ?_{_{{C}}}, where the sign of the angle is determined by the sign of the applied magnetic field. Therefore, subtracting the signals using +{B} and D{B} yields 2?_{_{{C}}}, allowing the absolute determination of ?_{_{{C}}}, without needing to remove the sample [1]. We demonstrate these absolute optical rotation measurements for chiral gases (?-pinene) and chiral liquids. This work is a proof-of-principle demonstration of the experimental setup proposed for the measurement of parity non-conserving optical rotation in atomic systems [1]. [1] L. Bougas, G. E. Katsoprinakis, W. von Klitzing, J. Sapirstein, and T. P. Rakitzis, Phys. Rev. Lett {108}, 210801 (2012).

  19. Tunable diode laser measurements of absolute linestrengths in the HNO3 band near 5.8 microns

    Science.gov (United States)

    May, Randy D.; Webster, Christopher R.; Molina, Luisa T.

    1987-01-01

    Absolute line strengths of selected lines in the nu 2 band of HNO3 have been measured using a tunable diode laser spectrometer operating in a sweep integration mode. The direct measurement technique has been employed to obtain line intensities at 296 K for 22 isolated lines in the 1720-1725/cm region. The reported line strengths have estimated uncertainties of 4 percent, a significant portion of this uncertainty arising from spectral interference from hot band transitions. From these line-strength measurements, an integrated band intensity of 1375/sq cm per atm at 296 K is inferred.

  20. 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

  1. 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)

  2. 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.

  3. 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

  4. Radioactivity measurement of 226Ra, 232Th, and 40K in environmental comparison sample using ? spectrometry

    International Nuclear Information System (INIS)

    The radioactivity analysis method of natural radionuclide 226Ra, 232Th and 40K is discussed. The environmental comparison sample which prepared by National Institute of Metrology is measured by using HPGe ? spectrometry. The radioactivities of 226Ra, 232Th and 40K in this sample are 179±20 Bq, 194±21 Bq and 565±62 Bq (k=2) respectively. The results are agreement with the reference radioactivities. (authors)

  5. Extrapolation chamber for absolute energy dose rate measurement of beta and soft x radiation

    International Nuclear Information System (INIS)

    A new extrapolation chamber is described, which is used as absolute standard for the determination of the absorbed beta radiation dose. The construction simulates a semi-infinite phantom and the absorbed dose to tissue was determined in tissue equivalent material. With a new system of concentric collecting electrodes it is possible to obtain the absorbed dose at the centre of the electrodes, which is extrapolated from five values of the surface of the collecting electrodes. (Author)

  6. The system for measurements of radioactive contamination of environment and food in Poland

    International Nuclear Information System (INIS)

    The service for Measurements of Radioactive Contamination comprises a network of 152 measuring stations. They are carrying out continuous measurements of gamma radiation dose rates and radioactivity measurements of 24 hours samples of air (aerosols) and total fallout. On the territory of each province there are selected points for sampling of environmental materials and food. Frequency of sampling depends on material being collected. 1 tab., 2 figs. (A.S.)

  7. Absolute nuclear material assay

    Science.gov (United States)

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

    2012-05-15

    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.

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

    OpenAIRE

    Chenais, Sébastien; Forget, Sébastien; Druon, Frédéric; Balembois, François; Georges, Patrick

    2004-01-01

    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.

  9. Measurement of the radioactivity distribution of material surfaces with an imaging plate

    International Nuclear Information System (INIS)

    An imaging plate has a very high sensitivity, and it is useful for in situ measurements of the distribution of extremely low levels of radioactivity, down to about 10-3 Bq/mm2, of material surfaces such as stones, vegetables etc. A method to determine the radioactivity is proposed in such applications. ((orig.))

  10. The lessons learnt from a series of radioactivity measurement intercomparison exercises

    International Nuclear Information System (INIS)

    Over the past decade, the National Physical Laboratory (NPL) has run a number of intercomparison exercises, aimed at those laboratories making measurements of radioactivity at environmental levels. The need for such intercomparisons were initially driven by the Chernobyl accident and it's aftermath. Immediately after the accident, many measurements were made of radioactivity in the UK environment, but the lack at that time of a coordinated programme of measurements, feeding into a dissemination centre did nothing to improve public confidence in such measurements. This situation was remedied by the Department of the Environment (DoE) in the years following Chernobyl. In the longer term this perceived (and in most cases, undeserved) lack of public confidence in 'official' data led many laboratories in the UK, with no statutory need to measure radioactivity, to equip themselves to be able to make measurements of radioactivity in food and other environmental materials

  11. Measurement of radioactive nuclides in the `Mayak` region

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.)

  12. 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.)

  13. Demands on quality control of radioactivity measurements and examples of how to perform it

    International Nuclear Information System (INIS)

    The official measuring points of the federal states to monitor environmental radiactivity have to meet certain demands on quality assurance, and prove to the competent authorities of the respective state that their laboratories performed the appropriate quality controls in the field of radioactivity measurements. Other laboratories performing radioactivity measurements also have to undertake regular quality controls. Laboratory-internal and external controls which form part of quality controls in laboratories are briefly described. (orig./DG)

  14. Surveillance of radioactivity in the atmosphere between prognosis and measurement - early alert in the Deutscher Wetterdienst

    International Nuclear Information System (INIS)

    The Deutscher Wetterdienst (DWD) 'German Meteorological Service' is legally responsible for the large-scale surveillance of radioactivity in the atmosphere. For an early alert of artificial radioactivity gamma-ray-spectrometry of aerosols is performed at selected meteorological stations of the synoptic-climatological network. Results of measurements as well as dispersion calculations are urgently required for making further decisions. The combination of measurements and forecasts combined with airborne measurements in an alert-situation is discussed. (orig.)

  15. Results of questionaire survey for the measurement of radioactivity in waste water

    International Nuclear Information System (INIS)

    A questionaire for radioactivity in waste water was sent to 388 facilities, including 158 medical facilities, and all (100%) answered. Information requested included: (1) kinds and annual usage of unsealed RI, (2) measuring method of radioactivity in waste water, (3) kinds of measuring instruments and the detection limits, (4) prior treatment of measurement materials, (5) level of radioactive waste exhausted during 3 months, (6) personnel and time per month required for radioactivity measurement, (7) problems and comments in waste water management, and (8) kinds of facilities. A total of 36 unsealed RI were used. The most commonly used RI was I-125 (n=240), followed by H-3 (n=189) and P-32 (n=179). Annual level of RI was 4 GBq or less in 90% of the facilities. The most common method for measuring radioactivity was sampling method (n=241). The most common instrument for measuring radioactivity was a gamma counter for I-125 (45% of the facilities), and a liquid scintillation counter for P-32 (80%) and for C-14 and H-3 (90%). The detection limits for I-125 exceeded the radioactivity limits in 24% of the facilities. The amount of sampler was 5 cc or less in 80% of the facilities. Prio treatment was not carried out in 62.7%. Prior treatment methods reported were enrichment, evaporation, pH adjustment, and sedimentation. Half of the facilities exhausted 10 cm3 or less of waste water during 3 months. The number of persons engaging in radioactivity measurement per engaging in radioactivity measurement per month was reported to be one in 282 facilities (87%). (N.K.)

  16. 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

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

    CERN Document Server

    Kuramoto, Yoshiyuki

    2014-01-01

    We present an absolute distance measurement interferometer based on a two wavelength interferometer and a variable synthetic wavelength technique. The wavelength scanning range was 12 GHz, realized with a phase accuracy of 1.0 m{\\lambda} by heterodyne detection at each measurement wavelength. This small wavelength scanning range enabled the use of distributed feedback laser diodes as an interferometer light source and a fast 20 ms wavelength scanning time by injection current control. We demonstrated a measurement range of up to 1.5 m and an accuracy better than 1.2 nm in comparison with a displacement measurement interferometer, corresponding to a relative accuracy of 10-9. In addition, we also proposed expanding the range of maximum measurement and compensation of refractive index of air for linear colliders.

  18. A fast signal subspace approach for the determination of absolute levels from phased microphone array measurements

    Science.gov (United States)

    Sarradj, Ennes

    2010-04-01

    Phased microphone arrays are used in a variety of applications for the estimation of acoustic source location and spectra. The popular conventional delay-and-sum beamforming methods used with such arrays suffer from inaccurate estimations of absolute source levels and in some cases also from low resolution. Deconvolution approaches such as DAMAS have better performance, but require high computational effort. A fast beamforming method is proposed that can be used in conjunction with a phased microphone array in applications with focus on the correct quantitative estimation of acoustic source spectra. This method bases on an eigenvalue decomposition of the cross spectral matrix of microphone signals and uses the eigenvalues from the signal subspace to estimate absolute source levels. The theoretical basis of the method is discussed together with an assessment of the quality of the estimation. Experimental tests using a loudspeaker setup and an airfoil trailing edge noise setup in an aeroacoustic wind tunnel show that the proposed method is robust and leads to reliable quantitative results.

  19. 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.

  20. 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)

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

    CERN Document Server

    Holt, Craig R

    2014-01-01

    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...

  2. 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

  3. 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)

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

    CERN Document Server

    Aubert, B; Abrams, G S; Adye, T; Ahmed, M; Ahmed, S; Alam, M S; Albert, J; Aleksan, Roy; Allen, M T; Allison, J; Allmendinger, T; Altenburg, D; Andreassen, R; Andreotti, M; Angelini, C; Anulli, F; Arnaud, N; Aston, D; Azzolini, V; Baak, M; Back, J J; Baldini-Ferroli, R; Band, H R; Banerjee, S; Barate, R; Bard, D J; Barlow, N R; Barlow, R J; Barrett, M; Bartoldus, R; Batignani, G; Battaglia, M; Bauer, J M; Beck, T W; Behera, P K; Bellini, F; Benayoun, M; Benelli, G; Berger, N; Bernard, D; Berryhill, J W; Best, D; Bettarini, S; Bettoni, D; Bevan, A J; Bhimji, W; Bhuyan, B; Bianchi, F; Biasini, M; Biesiada, J; Blanc, F; Blaylock, G; Blinov, A E; Blinov, V E; Bloom, P; Bomben, M; Bondioli, M; Bonneaud, G R; Bosisio, L; Boutigny, D; Bowerman, D A; Boyarski, A M; Boyd, J T; Bozzi, C; Brandenburg, G; Brandt, T; Brau, J E; Breon, A B; Briand, H; Brose, J; Brown, C L; Brown, C M; Brown, D; Brown, D N; Bruinsma, M; Brunet, S; Bucci, F; Buchanan, C; Buchmüller, O L; Bugg, W; Bukin, A D; Bula, R; Bulten, H; Burchat, P R; Burke, J P; Button-Shafer, J; Buzzo, A; Bóna, M; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Capra, R; Carpinelli, M; Cartaro, C; Cavallo, N; Cavoto, G; Cenci, R; Chai, X; Chaisanguanthum, K S; Chao, M; Charles, E; Charles, M J; Chauveau, J; Chavez, C A; Chen, A; Chen, C; Chen, E; Chen, J C; Chen, S; Chen, X; Cheng, B; Cheng, C H; Chevalier, N; Cibinetto, G; Clark, P J; Claus, R; Cochran, J; Coleman, J P; Contri, R; Convery, M R; Cormack, C M; Cossutti, F; Cottingham, W N; Couderc, F; Covarelli, R; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L; Cristinziani, M; Cunha, A; Curry, S; Côte, D; D'Orazio, A; Dahmes, B; Dallapiccola, C; Danielson, N; Dasu, S; Datta, M; Dauncey, P D; David, P; Davier, M; Davis, C L; Day, C T; De Groot, N; De Nardo, Gallieno; De Sangro, R; Del Buono, L; Del Re, D; Della Ricca, G; Di Lodovico, F; Di Marco, E; Dickopp, M; Dingfelder, J C; Dittongo, S; Dong, D; Dorfan, J; Druzhinin, V P; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Dvoretskii, A; Eckhart, E A; Eckmann, R; Edgar, C L; Edwards, A J; Egede, U; Eichenbaum, A M; Eigen, G; Eisner, A M; Elmer, P; Emery, S; Ernst, J A; Eschenburg, V; Eschrich, I; Eyges, V; Fabozzi, F; Faccini, R; Fan, S; Feltresi, E; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Flacco, C J; Flack, R L; Flächer, H U; Flood, K T; Ford, K E; Ford, W T; Forster, I J; Forti, F; Fortin, D; Foulkes, S D; Franek, B; Frey, R; Fritsch, M; Fry, J R; Fulsom, B G; Gabathuler, E; Gaidot, A; Gaillard, J R; Galeazzi, F; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gary, J W; Gaspero, M; Gatto, C; George, K A; Gill, M S; Giorgi, M A; Giroux, X; Gladney, L; Glanzman, T; Godang, R; Goetzen, K; Golubev, V B; Gopal, G P; Gowdy, S J; Gradl, W; Graham, M; Grancagnolo, S; Graugès-Pous, E; Graziani, G; Green, M G; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Guo, Q H; Hadavand, H K; Hadig, T; Haire, M; Halyo, V; Hamano, K; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, A J; Hartfiel, B L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hill, E J; Hirschauer, J F; Hitlin, D G; Hodgkinson, M C; Hollar, J J; Hong, T M; Honscheid, K; Hopkins, D A; Hrynóva, T; Hufnagel, D; Hulsbergen, W D; Hutchcroft, D E; Höcker, A; Igonkina, O; Innes, W R; Izen, J M; Jackson, P D; Jackson, P S; Jacobsen, R G; Jawahery, A; Jessop, C P; John, M J J; Johnson, J R; Judd, D; Kadel, R W; Kadyk, J; Kagan, H; Karyotakis, Yu; Kass, R; Kelly, M P; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Kitayama, I; Klose, V; Knecht, N S; Koch, H; Kocian, M L; Koeneke, K; Kofler, R; Kolomensky, Yu G; Koptchev, V B; Kovalskyi, D; Kowalewski, R V; Kozanecki, Witold; Kravchenko, E A; Kreisel, A; Krishnamurthy, M; Kroeger, R; Kroseberg, J; Kukartsev, G; Kutter, P E; Kyberd, P; La Vaissière, C de; Lacker, H M; Lae, C K; Lafferty, G D; Lanceri, L; Lange, D J; Langenegger, U; Lankford, A J; Latham, T E; Lau, Y P; Lazzaro, A; Le Diberder, F R; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Lewandowski, B; Li Gioi, L; Li, H; Li, X; Libby, J; Lista, L; Liu, R; Lo Vetere, M; LoSecco, J M; Lockman, W S; Lombardo, V; London, G W; Long, O; Lou, X C; Lu, M; Luitz, S; Lund, P; Luppi, E; Lusiani, A; Lutz, A M; Lynch, G; Lynch, H L; Lü, C; Lüth, V; MacFarlane, D B; Macri, M; Mader, W F; Majewski, S A; Malcles, J; Mallik, U; Mancinelli, G; Mandelkern, M A; Marchiori, G; Margoni, M; Marks, J; Marsiske, H; Martínez-Vidal, F; Mattison, T S; Mayer, B; Mazur, M A; Mazzoni, M A; McKenna, J A; McMahon, T R; Meadows, B T; Mellado, B; Menges, W; Messner, R; Meyer, W T; Mihályi, A; Minamora, J S; Mir, L M; Mohanty, G B; Mohapatra, A K; Mommsen, R K; Monge, M R; Monorchio, D; Moore, T B; Morandin, M; Morgan, S E; Morganti, M; Morganti, S; Morii, M

    2006-01-01

    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).

  5. An absolute measurement of the probability for 1s sigma and 2p sigma excitation of the lead K shell

    International Nuclear Information System (INIS)

    Using paticle x-ray techniques, the probability for K shell ionization has been measured absolutely at two impact parameters for collisions of 5.8 MeV/amu 208Pb on Ag and Au. In the asymmetric collision system Pb K shell is 2.2% at 25 fm impact parameter, and an exponential probability distribution falls off too quickly to account for the neasurement total cross section. For the symmetric system Pb-Au, the latter conclusion is also made for the 2p sigma excitation probability although in this case, the probability is much larger being 29% at 42 fm. (orig.)

  6. Absolute measurement of /sup 235/U fission cross section induced by 14. 2 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Li Jingwen; Shen Guanren; Ye Zongyuan; Li Anli; Zhou Shuhua; Sun Zhongfa; Wu Jingxia; Huang Tangzi; Yue Gang; Shi Detang; and others

    1988-08-01

    Absolute measurement of the fission cross section of /sup 235/U induced by 14.2 MeV neutrons is performed by the time correlated associated particle method. The reaction T(d, n)/sup 4/He is used as neutron source. The deuteron beam of 220 keV is produced from the Cockcroft-Walton generator. The associated alpha particles are detected by a thin plastic scintillator positioned at angle 90/sup 0/ with respect to the incident deuteron beam. The fission detector is an ionization chamber of fast current type.

  7. Measurement of the Absolute Branching Ratio for the K+ -> mu+ nu(gamma) Decay with the KLOE Detector

    CERN Document Server

    Ambrosino, F; Antonelli, M; Bacci, C; Beltrame, P; Bencivenni, G; Bertolucci, Sergio; Bini, C; Bloise, C; Bocci, V; Bossi, F; Bowring, D; Branchini, P; Caloi, R; Campana, P; Capon, G; Capussela, T; Ceradini, F; Chi, S; Chiefari, G; Ciambrone, P; Conetti, S; De Lucia, E; De Simone, P; De Zorzi, G; Dell'Agnello, S; Denig, A; Di Domenico, A; Di Donato, C; Di Falco, S; Di Micco, B; Doria, A; Dreucci, M; Felici, G; Ferrari, A; Ferrer, M L; Finocchiaro, G; Forti, C; Franzini, P; Gatti, C; Gauzzi, P; Giovannella, S; Gorini, E; Graziani, E; Incagli, M; Kluge, W; Kulikov, V; Lacava, F; Lanfranchi, G; Lee-Franzini, J; Leone, D; 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; Pontecorvo, L; Primavera, M; Santangelo, P; Santovetti, E; Saracino, G; Sciascia, B; Sciubba, A; Scuri, F; Sfiligoi, I; Spadaro, T; Testa, M; Tortora, L; Valente, P; Valeriani, B; Venanzoni, G; Veneziano, Stefano; Ventura, A; Versaci, R

    2006-01-01

    We have measured the fully inclusive K+ -> mu+nu(gamma) absolute branching ratio with the KLOE experiment at DAFNE, the Frascati Phi-factory. From some 865,283 K+ -> mu+nu(gamma) decays obtained from a sample of about 5.2x10^8 Phi-meson decays, we find BR(K+ -> mu+ nu (gamma)) = 0.6366 +-0.0009(stat.) +-0.0015(syst.), corresponding to an overall fractional error of 0.27%. Using recent lattice results on the decay constants of pseudoscalar mesons one can obtain an estimate for the CKM mixing matrix element |Vus|=0.2223+-0.0026.

  8. Measures of preventing contamination of radioactive solid waste in the compaction sealing package process

    International Nuclear Information System (INIS)

    Based on the radioactive solid waste compaction sealing Package machine, the preventing facilities and their effects during operation are described. The result shows that the compaction sealing package process of radioactive solid waste, prevention measures should be supplemented by means of ventilation to keep the workshop under certain negative pressure. The monitoring data show that after applying the measures mentioned above, the concentration of airborne radioactive nuclide would be 1/30 of (GB4792-84) DAC national standard, and the contamination level would be under control

  9. 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

  10. 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)

  11. Absolute optical oscillator strengths for the electronic excitation of atoms at high resolution: Experimental methods and measurements for helium

    International Nuclear Information System (INIS)

    An alternative method is described for the measurement of absolute optical oscillator strengths (cross sections) for electronic excitation of free atoms and molecules throughout the discrete region of the valence-shell spectrum at high energy resolution (full width at half maximum of 0.048 eV). The technique, utilizing the virtual-photon field of a fast electron inelastically scattered at negligible momentum transfer, avoids many of the difficulties associated with the various direct optical techniques that have traditionally been used for absolute optical oscillator strength measurements. The method is also free of the bandwidth (line saturation) effects that can seriously limit the accuracy of photoabsorption cross-section measurements for discrete transitions of narrow linewidth obtained using the Beer-Lambert law [I0/I=exp(nl?p)]. Since the line-saturation effects are not widely appreciated and are only usually considered in the context of peak heights, a detailed analysis of this problem is presented, with consideration of the integrated cross section (oscillator strength) over the profile of each discrete peak

  12. 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.'

  13. 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)

  14. The measurement of radioactivity in tomatoes cultivated on mining residues from the Oka niobium mining community

    International Nuclear Information System (INIS)

    The radioactivity contained in the tailings of a niobium mine in the Oka region, Quebec, was the object of concern for the population of the area in 1979. To find the impact of these tailings on fruit and vegetables grown in this environment, an investigation of the radioactivity found on tomatoes grown in green houses in niobium tailings and in vermiculites was undertaken. The tailings contained a high level of natural radioactivity and a small amount of 137Cs while the vermiculites has a very low level of natural radioactivity and an appreciable amount of 137Cs. Cesium-137 was the only nuclide detected in tomato ashes in measurable quantity. Absence of natural radioactivity is explained by its presence as insoluble minerals. (author)

  15. Exact method for determining subsurface radioactivity depth profiles from gamma spectroscopy measurements

    CERN Document Server

    Van Siclen, Clinton DeW

    2011-01-01

    Subsurface radioactivity may be due to transport of radionuclides from a contaminated surface into the solid volume, as occurs for radioactive fallout deposited on soil, or from fast neutron activation of a solid volume, as occurs in concrete blocks used for radiation shielding. For purposes including fate and transport studies of radionuclides in the environment, decommissioning and decontamination of radiation facilities, and nuclear forensics, an in situ, nondestructive method for ascertaining the subsurface distribution of radioactivity is desired. The method developed here obtains a polynomial expression for the radioactivity depth profile, using a small set of gamma-ray count rates measured by a collimated detector directed towards the surface at a variety of angles with respect to the surface normal. To demonstrate its capabilities, this polynomial method is applied to the simple case where the radioactivity is maximal at the surface and decreases exponentially with depth below the surface, and to the ...

  16. Measurement of tissue blood flow with diffusible radioactive indicators

    International Nuclear Information System (INIS)

    The determination of blood flow of different organs or tissues is of a great interest in the study of blood circulation. The authors relate the experience they have had in this field for the last twelve years, using the diffusible radioactive indicator technique. The theoretical bases of this technique have been excluded from this paper, which is essentially practical. Through analytical description of the works concerning myocardium, striated muscle, kidney, uterus, osseous and bronchial tissues, several interesting notions appear. First, contribution to pharmacological or functional stimulation tests is clearly illustrated by our investigation method of striated muscle. Second, the meaning of the blood flow thus determined is identical to a real nutritional capillary flow. Third, the Pertechnetate represents a very good radioactive tracer for the determination of low value blood flows, an original notion

  17. Measurement of radioactivity induced by GeV-protons and spallation neutrons using AGS accelerator

    International Nuclear Information System (INIS)

    Measurement of radioactivity induced by high-energy protons with energy of 2.83 and 24 GeV and spallation neutrons produced by bombarding a mercury target with the high-energy protons were performed by using the AGS (Alternative Gradient Synchrotron) accelerator at Brookhaven National Laboratory. The samples of boron, carbon, aluminum, iron, copper, niobium, mercury-oxide, lead, bismuth, acrylic resin, SS-316, Inconel-625 and Inconel-718 were irradiated around the mercury target. After the irradiation, the radioactivity of each sample was measured by using HPGe detectors at the cooling time between 2 h and 200 d. In the processing of the measured ?-ray spectra, more than 90 radioactive nucleus were identified, and the radioactivity production data were obtained. This report gives the experimental procedure, the data processing and the experimental results. (author)

  18. Gamma radioactivity measurements in Nile River sediment samples

    OpenAIRE

    ISSA, Shams; UOSIF, Mohamed; ELSAMAN, Reda

    2013-01-01

    River sediment depositions on the bottom of rivers most frequently consist of sand and gravel particles with different grain sizes, which make them particularly valuable for building construction. Knowledge of the radioactivity present in building materials enables one to assess any possible radiological hazard to humankind by the use of such materials. A total of 69 Nile River sediment samples from 8 cities and 24 locations were collected along a 139-km area in Minia, Egypt. The rad...

  19. Measurement of absolute gamma-ray emission probabilities from decay of 138Xe.

    Science.gov (United States)

    Xie, Feng; Jiang, Wengang; He, Xiaobing; Li, Xuesong; Cheng, Zhanyin; Wang, Shilian; Li, Qi; Shi, Quanlin; Chang, Yongfu

    2013-10-01

    The fission gaseous (138)Xe products play an important role in the research of nuclear-reaction products and radioisotope applications. Therefore, precise data for emission probabilities of gamma-ray from decay of (138)Xe are highly desired. However, a high precision is not achievable with a sufficient accuracy due to the limitations of the usual experimental techniques. In this paper, after the homogeneous sources of (138)Xe-(138)Cs were prepared, the activity of (138)Xe was obtained by the decay relationship between (138)Xe and (138)Cs using a HPGe detector. The full-energy peak efficiencies of gamma-ray for (138)Xe and (138)Cs were accurately calibrated using many activity standard sources and self-absorption was corrected. As a result, the absolute emission probabilities of the 258.4, 434.6 and 1768.3 keV gamma-ray from decay of (138)Xe were determined to be 34.9(10)%, 22.2(6)% and 18.8(5)%, respectively. PMID:23827509

  20. Comparative measurements of plant radioactivity in the Agrobotanical Garden and experimental fields

    Directory of Open Access Journals (Sweden)

    Stefan TAMAS

    1986-08-01

    Full Text Available In order to demonstrate the usefulness of the Garden's Catalogue in unforeseen situations, the radioactivity of some plant species cultivated on different plots of the Agrobotanical Garden has been measured in May 1986. Comparative measurements have been carried out on species harvested from the experimental fields Sapca-Verde (Cluj-Napoca and from a collection trip in Tulcea county (Tulcea, Babadag, too. A monocanal energy spectrometer NK-350 (Gamma has been used for measurements; impulses per minute have been registered and plant radioactivity expressed in Becquerel (Bq units has been calculated. The highest values have been measured in the Agrobotanical Garden (alt. s.m. 475 m, incl. about 200 , exp. NE. Small-leaved low stature plants of Cyperaceae and Poaceae family have been much more radioactive than large-leaved Brassicaceae. In 28th May 1986 plants were generally more radioactive at basis as on top; older stems were 4-6 times more radioactive than top leaves or regrowth after harvest. Washing in running water (100 gr fresh weight in 50 l water for 5 minutes reduced the radioactivity levels measured in different species with about 30%.

  1. Absolute advantage

    OpenAIRE

    Marrewijk, J. G. M.

    2008-01-01

    A country is said to have an absolute advantage over another country in the production of a good or service if it can produce that good or service using fewer real resources. Equivalently, using the same inputs, the country can produce more output. The concept of absolute advantage can also be applied to other economic entities, such as regions, cities, or firms, but we will focus attention on countries, specifically in relation to their production decisions and international t...

  2. Possibility of gas flow measurements using ionization produced by radioactive sources. Performance obtained using continuous and pulsed ionization

    International Nuclear Information System (INIS)

    Two methods for measuring gas flow have been studied, based on the ionization of the fluid by a radioactive source. In the first one, called the continuous method, use is made of the relationship between the flow and the ionic density at a point situated down-stream from the ionizing source. In the second method, called 'pulsed', the time for a burst of ions to pass between two points in the circuit is measured. An attempt has been made to predict and to justify theoretically the experimental results, and to determine to what extent these methods can provide absolute measurements or measurements requiring a calibration using known gas flows. These methods are characterized by the absence of moving parts or of parts under reduced pressure and can yield results with an accuracy of between a few per cent to a few tenths of a per cent. The information, provided in either analog or digital form, can be adapted for use in servo-mechanisms or automatic systems. Two applications of an industrial type are described; they concern gas-flow measurements in a railway braking circuit, and in tubes of 20 and 30 cm diameter. (author)

  3. Reinterpretation of the recently measured absolute generalized oscillator strength for the Ar 3p-4p transition

    International Nuclear Information System (INIS)

    The recent experimental observation of the absolute generalized oscillator strength (GOS) for the Ar 3p-(4p,4p') nondipole transition has been interpreted as a manifestation of quadrupole excitation [X. W. Fan and K. T. Leung, Phys. Rev. A 62, 062703 (2000)]. Contrary to the experimentalists' assignment, on the grounds of our random-phase-approximation with exchange (RPAE) calculation, we attribute the measured GOS to combined monopole, the dominant component, and quadrupole contributions. Our RPAE GOS's for the Ar dipole 3p-4s and 3p-3d,5s and the lowest nondipole transitions are compared with the measurements. The results could have significant implications for other similar transitions, previously interpreted as quadrupole excitation and for interpreting other discrete transitions

  4. Absolute depth-dose-rate measurements for an 192Ir HDR brachytherapy source in water using MOSFET detectors

    International Nuclear Information System (INIS)

    Reported MOSFET measurements concern mostly external radiotherapy and in vivo dosimetry. In this paper, we apply the technique for absolute dosimetry in the context of HDR brachytherapy using an 192Ir source. Measured radial dose rate distributions in water for different planes perpendicular to the source axis are presented and special attention is paid to the calibration of the R and K type detectors, and to the determination of appropriate correction factors for the sensitivity variation with the increase of the threshold voltage and the energy dependence. The experimental results are compared with Monte Carlo simulated dose rate distributions. The experimental results show a good agreement with the Monte Carlo simulations: the discrepancy between experimental and Monte Carlo results being within 5% for 82% of the points and within 10% for 95% of the points. Moreover, all points except two are found to lie within the experimental uncertainties, confirming thereby the quality of the results obtained

  5. Two-color laser-induced incandescence (2C-LII) technique for absolute soot volume fraction measurements in flames

    Science.gov (United States)

    de Iuliis, Silvana; Cignoli, Francesco; Zizak, Giorgio

    2005-12-01

    A two-color version of the laser-induced incandescence (2C-LII) technique was implemented for measuring absolute soot volume fraction in flames. By using a calibrated tungsten ribbon lamp, soot peak temperatures were measured as a function of fluence at several locations in an ethylene diffusion flame by using a steeply edged laser beam profile. Above a certain fluence threshold, peak temperatures were tightly distributed just above 4000 K independent of the particle size and number density. Radial profiles of soot volume fraction were obtained and compared (not calibrated) with results from the laser extinction technique. Good agreement showed the validity of the 2C-LII technique at a controlled fluence.

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

    Science.gov (United States)

    Som, Sumit; Seth, Sudeshna; Mandal, Aditya; Paul, Saikat; Duttagupta, Anjan

    2013-02-01

    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(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. PMID:23464200

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

    International Nuclear Information System (INIS)

    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 ±0.20, 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.

  8. Measurements of radioactive and xenobiotic substances in the biological environment in the Netherlands 1986

    International Nuclear Information System (INIS)

    A brief survey of the results of detailed radioactivity measurements performed in the Netherlands during the period immediately after the Chernobylsk accident, and the risk analyses made on the basis of these results, are presented. The increase of the airborne radioactivity and the activity concentrations in surface water during the first week of May 1986 is demonstrated graphically. The radiation dose in 1986 due to artificial radioactivity has been calculated to be about 60 ?Sv for adults, 70 ?Sv for ten-year-old children and 110 ?Sv for one-year-old children. 54 figs.; 32 tabs

  9. Measurement of radioactivity in the atmosphere and pollution nearby an atomic centre

    International Nuclear Information System (INIS)

    The French Atomic Energy Commission (CEA) is particularly interested in studies on atmospheric radioactivity by reason of the necessity to control the atmosphere nearby nuclear plants as uranium mines, nuclear reactors and hot laboratories or radioactive materials treatment plants. Thus, the CEA developed different apparatus to control and monitor the atmosphere nearby its sites. These air monitors are essentially of two types: the first one, called 'Babar', monitors smokes, fogs and dusts, the second type is an ionization chamber and measures the concentration of radioactive gas in the air. The functioning and sensitivity of these two systems are discussed. (M.P.)

  10. Micrometry combined with profile mapping for the absolute measurement of Integrated Column Density (ICD) and for accurate X-ray mass attenuation coefficients using XERT

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M. Tauhidul; Rae, Nicholas A.; Glover, Jack L.; Barnea, Zwi [School of Physics, University of Melbourne, Victoria 3010 (Australia); Chantler, Christopher T., E-mail: chantler@physics.unimelb.edu.a [School of Physics, University of Melbourne, Victoria 3010 (Australia)

    2010-07-21

    Absolute values of the column densities [{rho}t]{sub c} of four gold foils were measured using micrometry combined with the 2D X-ray attenuation profile. The absolute calibration of [{rho}t]{sub c} was made with a reference foil and the [{rho}t]{sub c} of other foils were determined following the thickness transfer method. By this method, we obtain absolute calibration to 0.1% or better which was not possible using only the X-ray map of a single foil over its central region.

  11. Micrometry combined with profile mapping for the absolute measurement of Integrated Column Density (ICD) and for accurate X-ray mass attenuation coefficients using XERT

    International Nuclear Information System (INIS)

    Absolute values of the column densities [?t]c of four gold foils were measured using micrometry combined with the 2D X-ray attenuation profile. The absolute calibration of [?t]c was made with a reference foil and the [?t]c of other foils were determined following the thickness transfer method. By this method, we obtain absolute calibration to 0.1% or better which was not possible using only the X-ray map of a single foil over its central region.

  12. Micrometry combined with profile mapping for the absolute measurement of Integrated Column Density (ICD) and for accurate X-ray mass attenuation coefficients using XERT

    Science.gov (United States)

    Islam, M. Tauhidul; Rae, Nicholas A.; Glover, Jack L.; Barnea, Zwi; Chantler, Christopher T.

    2010-07-01

    Absolute values of the column densities [?t]c of four gold foils were measured using micrometry combined with the 2D X-ray attenuation profile. The absolute calibration of [?t]c was made with a reference foil and the [?t]c of other foils were determined following the thickness transfer method. By this method, we obtain absolute calibration to 0.1% or better which was not possible using only the X-ray map of a single foil over its central region.

  13. The estimation of uncertainty of radioactivity measurement on gamma counters in radiopharmacy

    International Nuclear Information System (INIS)

    In this paper the estimation of uncertainty of measurement of radioactivity on gamma counter in Laboratory for radioisotopes is presented. The uncertainty components, which are important for these measurements, are identified and taken into account while estimating the uncertainty of measurement.(author)

  14. A new method for the absolute radiance calibration for UV/vis measurements of scattered sun light

    Science.gov (United States)

    Wagner, T.; Beirle, S.; Dörner, S.; Penning de Vries, M.; Remmers, J.; Rozanov, A.; Shaiganfar, R.

    2015-05-01

    Absolute radiometric calibrations are important for measurements of the atmospheric spectral radiance. Such measurements can be used to determine actinic fluxes, the properties of aerosols and clouds and the short wave energy budget. Conventional calibration methods in the laboratory are based on calibrated light sources and reflectors and are expensive, time consuming and subject to relatively large uncertainties. Also, the calibrated instruments might change during transport from the laboratory to the measurement sites. Here we present a new calibration method for UV/vis instruments that measure the spectrally resolved sky radiance, like for example zenith sky Differential Optical Absorption Spectroscopy (DOAS-) instruments or Multi-AXis (MAX-) DOAS instruments. Our method is based on the comparison of the solar zenith angle dependence of the measured zenith sky radiance with radiative transfer simulations. For the application of our method clear sky measurements during periods with almost constant aerosol optical depth are needed. The radiative transfer simulations have to take polarisation into account. We show that the calibration results are almost independent from the knowledge of the aerosol optical properties and surface albedo, which causes a rather small uncertainty of about <7%. For wavelengths below about 330 nm it is essential that the ozone column density during the measurements is constant and known.

  15. A new method for the absolute radiance calibration for UV/vis measurements of scattered sun light

    Directory of Open Access Journals (Sweden)

    T. Wagner

    2015-05-01

    Full Text Available Absolute radiometric calibrations are important for measurements of the atmospheric spectral radiance. Such measurements can be used to determine actinic fluxes, the properties of aerosols and clouds and the short wave energy budget. Conventional calibration methods in the laboratory are based on calibrated light sources and reflectors and are expensive, time consuming and subject to relatively large uncertainties. Also, the calibrated instruments might change during transport from the laboratory to the measurement sites. Here we present a new calibration method for UV/vis instruments that measure the spectrally resolved sky radiance, like for example zenith sky Differential Optical Absorption Spectroscopy (DOAS- instruments or Multi-AXis (MAX- DOAS instruments. Our method is based on the comparison of the solar zenith angle dependence of the measured zenith sky radiance with radiative transfer simulations. For the application of our method clear sky measurements during periods with almost constant aerosol optical depth are needed. The radiative transfer simulations have to take polarisation into account. We show that the calibration results are almost independent from the knowledge of the aerosol optical properties and surface albedo, which causes a rather small uncertainty of about <7%. For wavelengths below about 330 nm it is essential that the ozone column density during the measurements is constant and known.

  16. Establishment of a force balanced piston gauge for very low gauge and absolute pressure measurements at NPL, India

    International Nuclear Information System (INIS)

    National Physical Laboratory, the National Metrology Institute (NMI) of India is maintaining Primary standards of pressure that cover several decades of pressure, starting from 3.0E-06 Pa to 1.0 GPa. Among which a recent addition is a Force Balanced Piston Gauge, the non-rotating piston type, having better resolution and zero stability compared to any other primary pressure standards commercially available in the range 1.0 Pa to 15.0 kPa (abs and gauge). The characterization of this FPG is done against Ultrasonic Interferometer Manometer (UIM), the National Primary pressure standard, working in the range 1.0 Pa to 130.0 kPa (abs and diff) and Air Piston Gauge (APG), a Transfer Pressure Standard, working in the range 6.5 kPa to 360 kPa (abs and gauge), in their overlapping pressure regions covering both absolute and gauge pressures. As NPL being one of the signatories to the CIPM MRA, the Calibration and Measurement Capabilities (CMC) of both the reference standards (UIM and APG), are Peer reviewed and notified in the Key Comparison Data Base (KCDB) of BIPM. The estimated mean effective area of the Piston Cylinder assembly of this FPG against UIM (980.457 mm2) and APG (980.463 mm2) are well within 4 ppm and 10 ppm agreement respectively, with the manufacturer's reported value (980.453 mm2). The expanded uncertainty of this FPG, Q(0.012 Pa, 0.0025% of reading), evaluated against UIM as reference standard, is well within the reported valustandard, is well within the reported value of the manufacturer, Q(0.008 Pa, 0.003% of reading) at k = 2. The results of the characterization along with experimental setup and measurement conditions (for gauge and absolute pressure measurements), uncertainty budget preparation and evaluation of measurement uncertainty are discussed in detail in this paper.

  17. Surveillance of radioactivity by the German Meteorological Service. Automatic nuclide specific measurements

    International Nuclear Information System (INIS)

    The DWD (Deutscher Wetterdienst, German Meteorological Service) is charged by law with the surveillance of radioactivity in the atmosphere. In the frame of the ''Integrated Measuring and Information System for the Surveillance of Radioactivity in the Environment'' (IMIS) the measuring tasks of DWD are well described. Since 2009 it was aimed for the automatic measurement of aerosol-bound radionuclides, gaseous Iodine-131 and deposited radionuclides at the 48 measuring sites of DWD. To guarantee the continuous operation of germanium detectors it was necessary to install electrically cooled systems instead of systems cooled by liquid nitrogen. The technical details and the experiences are described.

  18. Experimental ship fire measurements with simulated radioactive cargo

    International Nuclear Information System (INIS)

    Results from a series of eight test fires ranging in size from 2.2 to 18.8 MW conducted aboard the Coast Guard fire test ship Mayo Lykes at Mobile, Alabama are presented and discussed. Tests aboard the break-bulk type cargo ship consisted of heptane spray fires simulating engine room and galley fires, wood crib fires simulating cargo hold fires, and pool fires staged for comparison to land-based regulatory fire results. Primary instrumentation for the tests consisted of two pipe calorimeters that simulated a typical package shape for radioactive materials packages. (authors)

  19. Experimental ship fire measurements with simulated radioactive cargo

    International Nuclear Information System (INIS)

    Results from a series of eight test fires ranging in size from 2.2 to 18.8 MW conducted aboard the Coast Guard fire test ship Mayo Lykes at Mobile, Alabama are presented and discussed. Tests aboard the break bulk type cargo ship consisted of heptane spray fires simulating engine room and galley fires, wood crib fires simulating cargo hold fires, and pool fires staged for comparison to land based regulatory fire results. Primary instrumentation for the tests consisted of two pipe calorimeters that simulated a typical package shape for radioactive materials packages

  20. Radioactive fallout in the South Pacific: a history Part 2: radioactivity measurements in the Pacific islands

    International Nuclear Information System (INIS)

    This report summarises results of the environmental radioactivity monitoring programme maintained in the Pacific islands by the National Radiation Laboratory (NRL) since 1961. Monitoring was commenced during the nuclear weapons tests at Christmas Island, then extended to a greater number of sites during the French atmospheric tests at Mururoa during 1966-1974 and maintained at that level until 1985 when the network was scaled down to its pres the monitoring of the French tests as the largest local source of short-lived fallout. These pacific monitoring operations during the period of 1960 to 1990 are reviewed which brings together and summarises the extensive compilation of data comprising 70 NRL report published during the period. An attempt is also made to correct the original data for decay between sampling and analysis. The average effective dose commitment for the South Pacific island population due to the entire history of atmospheric weapons tests is estimated to be 1.1 milli sievert.(author). 17 refs., 23 figs., tabs., ills

  1. MEASUREMENT AND CALCULATION OF ABSOLUTE SINGLE AND MULTIPLE CHARGE EXCHANGE CROSS SECTIONS FOR Fe q + IONS IMPACTING H2O

    International Nuclear Information System (INIS)

    Charge exchange (CE) plays a fundamental role in the collisions of solar- and stellar-wind ions with lunar and planetary exospheres, comets, and circumstellar clouds. Reported herein are absolute cross sections for single, double, triple, and quadruple CE of Fe q + (q = 5-13) ions with H2O at a collision energy of 7q keV. One measured value of the pentuple CE is also given for Fe 9 + ions. An electron cyclotron resonance ion source is used to provide currents of the highly charged Fe ions. Absolute data are derived from knowledge of the target gas pressure, target path length, and incident and charge-exchanged ion currents. Experimental cross sections are compared with new results of the n-electron classical trajectory Monte Carlo approximation. The radiative and non-radiative cascades following electron transfers are approximated using scaled hydrogenic transition probabilities and scaled Auger rates. Also given are estimates of cross sections for single capture, and multiple capture followed by autoionization, as derived from the extended overbarrier model. These estimates are based on new theoretical calculations of the vertical ionization potentials of H2O up to H2O10+.

  2. Measurement and Calculation of Absolute Single and Multiple Charge Exchange Cross Sections for Feg+ Ions Impacting H2O

    International Nuclear Information System (INIS)

    Charge exchange (CE) plays a fundamental role in the collisions of solar- and stellar-wind ions with lunar and planetary exospheres, comets, and circumstellar clouds. Reported herein are absolute cross sections for single, double, triple, and quadruple CE of Feq+ (q = 5-13) ions with H2O at a collision energy of 7q keV. One measured value of the pentuple CE is also given for Fe9+ ions. An electron cyclotron resonance ion source is used to provide currents of the highly charged Fe ions. Absolute data are derived from knowledge of the target gas pressure, target path length, and incident and charge-exchanged ion currents. Experimental cross sections are compared with new results of the n-electron classical trajectory Monte Carlo approximation. The radiative and non-radiative cascades following electron transfers are approximated using scaled hydrogenic transition probabilities and scaled Auger rates. Also given are estimates of cross sections for single capture, and multiple capture followed by autoionization, as derived from the extended overbarrier model. These estimates are based on new theoretical calculations of the vertical ionization potentials of H2O up to H2O10+.

  3. Decision for counting condition of radioactive waste activities measuring by Ludlum detector

    International Nuclear Information System (INIS)

    Radioactive waste must measured for activities before be throw out to environment. Measuring will be important in ordered to know activities can be given management direction. For activities radioactive waste on limit threshold value must processed, but for under limit threshold value activities can be throw out to environment. Activities measuring for solid radioactive waste and liquid by (Total, ?, ?) Ludlum detector connected Mode-1000 Scaler Counting. Before measuring for solid waste activities was decisioned optimally counting condition, and be obtained are : sample weight 3.5 gram, heating temperature of 125 oC and heating time at 60 minutes. Activities measuring result by total detector ranges from (0.68-0.71) 10-1 ?Ci/gram, ? detector ranges from (0.24-0.25) 10-1 ?Ci/gram and ? detector ranges from (0.35-0.37) ?Ci/gram

  4. Portable scintillation gamma-spectrometer for field measurement of radioactivity in extensive objects

    International Nuclear Information System (INIS)

    The portable scintillated gamma-spectrometer for field measurement of radioactivity in the volume objects was designed. The crystal CdWO4 that has weak dependence of light yield from temperature in combination with PMT was applied as the gamma-rays detector. The design of the device provides the possibility for measuring radioactivity of the extensive objects in 4?-geometry without background measurements. In this case the value of the efficiency needed for specific activity calculation in close approximation depends only from crystal geometry and density of measuring object and may be set as the device parameter without efficiency calibration procedure during the operation. The spectrometer does not have an auxiliary radio-active source and connecting cables in the composition. The smartphone operated under Windows Mobile is used as the control module. Bluetooth connection provides data exchange between smartphone and measurement head.

  5. Result of radioactive measurement of the airborne dust and fall-out

    International Nuclear Information System (INIS)

    The result of beta gross radioactivity of airborne dust was shown, fall-out and rain water measured in Pyongygang from 1969 to 1985. In the case of airborn dust the annual average value is ranged between 0.81 and 2.85 mBq/m3 and maximum value of monthly average is 13.36mBq/m3. The variation of radioactivity and the gamma spectrum of samples affected by nuclear test was considered. (author)

  6. Report on the spot investigation and measurements of non-radioactive wastes

    International Nuclear Information System (INIS)

    The report was prepared by Japan Nuclear Energy Safety Organization providing technical and useful information for those who want to make decision as a radioactive or non-radioactive wastes on the basis of the spot investigation and measurement including explanation of the clearance system. Also, the report contains the detailed results on the spot surveillance of the nuclear electricity production plant and the Rokkasho Reprocessing Plant. (S. Ohno)

  7. Measures Against-Illicit Trafficking of Nuclear Materials and Other Radioactive Sources

    International Nuclear Information System (INIS)

    Since the early nineties, illicit trafficking (IT) of nuclear materials and radioactive sources appeared as a new trend which raised the concern of the international community due to the grave consequences that would merge if these materials or radioactive sources fell into the hands of terrorist groups. However, by the end of the last century illicit trafficking of nuclear materials and radioactive sources lost its considerable salience, in spite of seizure of considerable amounts of 2'3'5U (76% enrichment) in Bulgaria (May 1999) and also 235U (30% enrichment) in Georgia (April 2000). Nevertheless, IT should be always considered as a continued and viable threat to the international community. Awareness of the problem should be developed and maintained among concerned circles as the first step towards combating illicit trafficking of nuclear materials and radioactive sources. Illicit trafficking of nuclear and radioactive materials needs serious consideration and proper attention by the governmental law enforcement authorities. Measures to combat with IT of nuclear material or radioactive sources should be effective in recovery, of stolen, removed or lost nuclear materials or radioactive sources due to the failure of the physical protection system or the State System Accounting and Control (SSAC) system which are normally applied for protecting these materials against illegal actions. Measures such as use of modern and efficient radiation monitoring equipment at the borders inspection points, is an important step in preventing the illicit trafficking of nuclear and radioactive materials across the borders. Also providing radiological training to specific personnel and workers in this field will minimize the consequences of a radiological attack in case of its occurrence. There is a real need to start to enter into cooperative agreements to strengthen borders security under the umbrella of IAEA to faster as an international cooperation in the illicit trafficking of nuclear material and radioactive sources

  8. Measures to ensure safety of radioactive materials in India

    International Nuclear Information System (INIS)

    In India, the use of ionizing radiation sources in industry, medicine, agriculture and research registered a significant increase during recent years. The basis of legislative control of the use of radiation in India is the Atomic Energy Act from 1962, which empowers the central Government to provide control over radioactive substances. Exercising these powers, the central Government has promulgated several radiation safety rules, which specify the requirements of licensing, the duties and responsibilities of radiation safety officers, powers of inspection, etc. Later in 1983, by the Act, the Atomic Energy Regulatory Board (AERB) was constituted by the central Government to exercise regulatory and safety functions. The report describes the existing system of regulatory control of radiation sources in India and in particular, refers to the regulatory documents prepared by the AERB, the type approval of radiation equipment, the regulatory consent for every person handling radioactive sources, and the inspection activities and enforcement of regulatory actions. The report also explains how management of disused sources is carried out in India, including the handling of accidents and emergency activities. (author)

  9. Development and application of a detector for absolute measurement of neutron fluence rate in MeV region

    International Nuclear Information System (INIS)

    The development and performance of the DTS (Dual Thin Scintillator) for the absolute measurement of the neutron fluence rate between 1 and 15 MeV is decribed. The DTS detector consists of a pair of organic scintillators in a dual configuration, where the incident produces a proton-recoil which is detected in a 2? geometry therefore avoiding the effect of the escape of protons. Thin scintillators are used resulting in small multiple scattering corrections. The theoretical caluclations of detector efficiency and proton-recoil spectrum were performed by means of a Monte Carlos code - CARLO DTS. The calculated efficiency was compared to the experimental one at two neutron energies namely 2.446 MeV and 14.04 MeV applying the Time Correlated Associated Particle technique. The theoretical and experimental efficiencies agreed within the experimental uncertainties of 1.44% and 0.77%, respectively. The performance of the DTS has been verified in an absolute 235U(n,f) cross section measurement between 1 and 6 MeV neutron energy. The cross section results were compared to those obtained replacing the DTS detector by the NBS (National Bureau of Standards, USA) Black Neutron Detector. The agreement was excellent in the overlapping energy interval of the two experiments (between 1 and 3 MeV), within the estimated uncertainly in the range of 1,0 to 1,7%. The agreement with the most recent evaluation from the ENDF/B-VI was excellent in almost all the energy range between 1 and 6 MeV. The 235U(n,f) cross section, average over the 252Cf fission neutron spectrum has been evaluated. The result including the cross section values of the present work was 1220 mb, in excellent agreement with the average value among the most recent measurements, 1227 +- 12 mb, and with the value 1213 mb, using the ENDF/B-VI data. (author)

  10. Improvements to the measurement of absolute cortical blood flow and its application to multi-head cameras: a feasibility study

    International Nuclear Information System (INIS)

    Full text:A program is described that performs Patlak graphical analysis of the brain uptake curve from the bolus phase of an ECD or HMPAO study. The aortic arch curve is used as the input function (Matsuda, EJNM 1992). This yields the unidirectional uptake coefficient that is related to absolute cortical blood flow (aCBF) in mil I O Og/min and transport of the agent into the neurons. The absolute nature of this measure has the potential to detect global cerebral microvascular or neuronal pathology that is not possible with the SPECT scan. Measuring aCBF with multiple camera heads permits its evaluation beyond the obligatory anterior view that primarily reflects frontal aCBF. Additional program features include correction for contamination of the aortic-arch (input) curve by activity from underlying vessels, better evaluation of the aortic-arch to brain delay, and subtraction of residual activity from a previous injection. We have ana lysed 17 patients at random (aged 40 to 90) who presented for HMPAO brain scans on a 3-head camera. Non aortic arch activity in the input curve underestimated aCBF by as much as 15%. aCBF was relatively unaffected by small changes in the aortic arch ROI or the bolus delay. Measured aCBF ranged from 10% above to 32% below the age-corrected normal value. The aCBF from the LPO and RPO views were at most II % below the ANT value. When a reliable age-dependence for aCBF in the normal aged population has been established, this technique can beas been established, this technique can be evaluated for the detection of changes in aCBF in early dementia.

  11. The radioactivity measurement in the Loire catchment basin. Actors, networks, data inventory

    International Nuclear Information System (INIS)

    The objective of this report on the Loire watershed was to broaden at all the nuclear installations of the watershed the method of synthesis made for Saint-Laurent-des-Eaux nuclear power plant, by resting on the whole of actors doing the radioactivity measurements in environment. This report shows that these actors are numerous. The measurement plans implemented have for objective to establish the radiological situation of environment, near or not the nuclear facilities, to detect the abnormal increase of radioactivity, to evaluate the exposure of populations to the ambient radioactivity, or to check the conformity of practices (nuclear activities) and products. This assessment enlightens the lack of a real global strategy in the organisation of the radioactivity measurement at the level of the watershed. The inventory of available data for the Loire watershed allowed to show the diversity of measurements realised. The I.R.S.N. is face to a complex situation of data return in the frame of the implementation of an information system of the national network of radioactivity measurement in environment. (N.C.)

  12. Radioactive preparations for the correction and control of gamma camera and scanner measurements in nuclear medicine

    International Nuclear Information System (INIS)

    Radioactive preparations to be used for the correction and the control of gamma camera and scanner measurements in nuclear medicine and as a reference system for comparative measurements are described. The spectra of the short-lived nuclides sup(99m)Tc and 131I could be simulated by means of 57Co and a combination of 133Ba + 137Cs. The radioactive materials were homogeneously merged into a epoxyresin combination from which plane sources and organ phantoms were produced. The preparations are easy to handle and allow the regular control of parameters to be measured by gamma cameras and scanners. (author)

  13. Absolute Thickness Measurements on Coatings Without Prior Knowledge of Material Properties Using Terahertz Energy

    Science.gov (United States)

    Roth, Don J.; Cosgriff, Laura M.; Harder, Bryan; Zhu, Dongming; Martin, Richard E.

    2013-01-01

    This study investigates the applicability of a novel noncontact single-sided terahertz electromagnetic measurement method for measuring thickness in dielectric coating systems having either dielectric or conductive substrate materials. The method does not require knowledge of the velocity of terahertz waves in the coating material. The dielectric coatings ranged from approximately 300 to 1400 m in thickness. First, the terahertz method was validated on a bulk dielectric sample to determine its ability to precisely measure thickness and density variation. Then, the method was studied on simulated coating systems. One simulated coating consisted of layered thin paper samples of varying thicknesses on a ceramic substrate. Another simulated coating system consisted of adhesive-backed Teflon adhered to conducting and dielectric substrates. Alumina samples that were coated with a ceramic adhesive layer were also investigated. Finally, the method was studied for thickness measurement of actual thermal barrier coatings (TBC) on ceramic substrates. The unique aspects and limitations of this method for thickness measurements are discussed.

  14. Research on temperature measurement technology for graphite-cone-absorption-cavity absolute calorimeter.

    Science.gov (United States)

    Wei, Ji Feng; Lu, Fei; Sun, Li Qun; Zhang, Kai; Hu, Xiao Yang; Zhou, Shan; Xu, De

    2015-02-01

    The nonlinear effect of materials and sensors in high-energy laser calorimeters is especially obvious-due to the steep temperature gradients of their absorbers. Significant measurement errors occur when traditional integral temperature sensors and methods are utilized. In an effort to remedy this, a method is proposed in this paper in which an absorption cavity is divided into many parts and multiple discrete thermocouple sensors are used to measure the temperature rise of the absorbers. The temperature distribution in the absorbers is theoretically analyzed, numerically simulated, and verified through experimentation. Energy measurement results are compared according to the temperature distribution for different layouts of thermocouples. A high-accuracy calorimeter is developed by setting and optimizing thermocouple layout, as well as correcting various elements such as the specific heat of graphite and responsivity of thermocouples. The calorimeter employing this measurement method is calibrated against a standard energy meter, resulting in correction coefficient of 1.027 and relative standard deviation of the correction coefficient of only 0.8%. Theoretical analysis, numerical simulation, and experimental verification all prove that the proposed method successfully improves measurement accuracy. PMID:25725875

  15. Absolute measurements of the continuum radiation to determine the electron density in a microwave-induced argon plasma

    Science.gov (United States)

    Iordanova, E.; de Vries, N.; Guillemier, M.; van der Mullen, J. J. A. M.

    2008-01-01

    A method for the determination of the electron density (ne) using the continuum radiation is presented. The radiation is calibrated with a standard tungsten ribbon lamp and thus expressed in absolute units. This method is applied to a microwave-induced argon plasma, created by a surfatron (2.45 GHz), for which the standard settings are: wavelength region at 648 nm, power of 60 W, pressure of 15 mbar, gas flow of 70 sccm and axial distance from the launcher of 3 cm. Due to the low degree of ionization, the influence of electron-ion interactions can be neglected; the radiation is predominantly generated by free-free interactions between electrons and atoms. The method provides the electron density values in the order of 1019 m-3 for different plasma settings. It is observed that the measured ne follows the well-known trends—it decreases in the direction of the propagating surface wave and increases with power.

  16. Absolute measurements of the continuum radiation to determine the electron density in a microwave-induced argon plasma

    International Nuclear Information System (INIS)

    A method for the determination of the electron density (ne) using the continuum radiation is presented. The radiation is calibrated with a standard tungsten ribbon lamp and thus expressed in absolute units. This method is applied to a microwave-induced argon plasma, created by a surfatron (2.45 GHz), for which the standard settings are: wavelength region at 648 nm, power of 60 W, pressure of 15 mbar, gas flow of 70 sccm and axial distance from the launcher of 3 cm. Due to the low degree of ionization, the influence of electron-ion interactions can be neglected; the radiation is predominantly generated by free-free interactions between electrons and atoms. The method provides the electron density values in the order of 1019 m-3 for different plasma settings. It is observed that the measured ne follows the well-known trends-it decreases in the direction of the propagating surface wave and increases with power

  17. Radioactivity measurement in Austria 1994 and 1995. Data and evaluation

    International Nuclear Information System (INIS)

    This report presents results of the radiation surveillance in Austria in the years 1994 and 1995, performed by the former Federal Ministry of Health and Consumer Protection, based on the Austrian Radiation Protection Act. In particular data of large scale monitoring concerning radioactive contaminations and of nuclear research reactor emission and immission control are given. By revision of the Federal Ministry Act the competence for these tasks has been turned over to the General Directorate VI of the Federal Chancellery. For the purpose of large scale surveillance on one hand an Early Radiation Warning System comprised of 336 gamma dose rate monitors is operated by the Federal Chancellery. The data are automatically communicated to various authorities in real-time. On the other hand the radionuclide content of various media such as air, precipitation, surface water, foodstuffs etc. is monitored via periodic sampling and analysis in the laboratory. In addition to this routine program special projects are carried out for investigation of specific media and to improve the knowledge of the time dependence respectively of regional aspects of the contamination situation. In the years 1994 and 1995 the average annual radiation exposure of the Austrian population amounted to about 4.6 mSv effective dose. The contributions dominating by far originate from natural and medical sources of radiation. Contributions of all other sources of radiation are extremely small in comparison with these. The average annual effective dose caused by natural radiation amounts to approximately 3.2 mSv. The inhalation of the radioactive noble gas radon and its short lived progeny in the mean contributes more than half to this exposure, but considerable variations occur. There are regions with particular geological conditions where the exposure due to radon by far exceeds all other exposures. (author)

  18. Proficiency Tests for Environmental Radioactivity Measurement Organized by an Accredited Laboratory

    Science.gov (United States)

    Aubert, Cédric; Osmond, Mélanie

    2008-08-01

    For 40 years, STEME (Environmental Sample Processing and Metrology Department) organized international proficiency testing (PT) exercises formerly for WHO (World Health Organization) and EC (European Community) and currently for ASN (French Nuclear Safety Authority). Five PT exercises are organized each year for the measurement of radionuclides (alpha, beta and gamma) in different matrixes (water, soil, biological and air samples) at environmental levels. ASN can deliver a French ministerial agreement to participate on environmental radioactivity measurements French network for laboratories asking it [1]. Since 2006, November, STEME is the first French entity obtaining a COFRAC (French Committee of Accreditation) accreditation as "Interlaboratory Comparisons" for the organization of proficiency tests for environmental radioactivity measurement according to standard International Standard Organization (ISO) 17025 and guide ISO 43-1. STEME has in charge to find, as far as possible, real sample or to create, by radionuclide adding, an adapted sample. STEME realizes the sampling, the samples preparation and the dispatching. STEME is also accredited according to Standard 17025 for radioactivity measurements in environmental samples and determines homogeneity, stability and reference values. After the reception of participating laboratories results, STEME executes statistical treatments in order to verify the normal distribution, to eliminate outliers and to evaluate laboratories performance. Laboratories participate with several objectives, to obtain French agreement, to prove the quality of their analytical performance in regards to standard 17025 or to validate new methods or latest developments. For 2 years, in addition to usual PT exercises, new PT about alpha or beta measurement in air filters, radioactive iodine in carbon cartridges or measurement of environmental dosimeters are organized. These PT exercises help laboratories to improve radioactive measurements and to rectify old mistakes. The PT exercises organized by STEME are becoming essential for French and some European laboratories working in radioactive measurements. The STEME organization, in respect of accreditation references, is presented.

  19. Some problems of absolute measurement of pure ?-nuclides by method of label

    International Nuclear Information System (INIS)

    Dependance od efficiency of nuclide to be measured on efficiency of label has been calculated on the base of theoretical modeling of the process of self-absorption, i.e., it is dependance on extrapolation of the label. These calculations have appeared to be useful for estimation of value of change of label efficiency and on the method of it's measurements. It has been shown that linear coefficient of extrapolation curve does not depend on the cource of selfabsorption but at the same time square-law coefficient has close connection to the self-absorption dispersion and hence to the method of sample preparation

  20. Absolute polarization measurements and natural lifetime in the 7 S 1/2 state of Cs

    OpenAIRE

    Bouchiat, M. A.; Guena, J.; Pottier, L.

    1984-01-01

    We report Hanle effect measurements of the relaxation in the 7 S1/2 state of cesium by collisions with cesium or buffer gas (helium) atoms in an electric field. The results show the relaxation of the spin polarization to remain isotropic in the adopted configuration, and justify the calibration procedure used in our recent measurements of parity violation in the 6 S-7 S transition of cesium. We also obtain the lifetime of the 7 S1/2 state : ?7 S = 48.5 ± 0.5 ns (and the depolarization cross...

  1. A standard method for the absolute calibration of in vivo measurement systems

    International Nuclear Information System (INIS)

    Recent technical advances and unique approaches to calibration now allow for improved calibration of in vivo measurement systems. The new approach utilizes Monte Carlo calculational techniques along with a library of Magnetic Resonance images consisting of 32 human or human-like phantoms. The library of whole body images is the largest of its kind currently available and a prime resource for expanded DOE efforts in worker health and safety. This technique will save user facilities time and funds in the calibration of in vivo measurement systems while at the same time allowing greater flexibility in the selection of calibrations appropriate for a subject's physical stature

  2. Procoagulant and platelet-derived microvesicle absolute counts determined by flow cytometry correlates with a measurement of their functional capacity

    Directory of Open Access Journals (Sweden)

    Lisa Ayers

    2014-09-01

    Full Text Available Background: Flow cytometry is the most commonly used technology to measure microvesicles (MVs. Despite reported limitations of this technique, MV levels obtained using conventional flow cytometry have yielded many clinically relevant findings, such as associations with disease severity and ability to predict clinical outcomes. This study aims to determine if MV enumeration by flow cytometry correlates with a measurement of their functional capacity, as this may explain how flow cytometry generates clinically relevant results. Methods: One hundred samples from healthy individuals and patients with obstructive sleep apnoea were analysed by conventional flow cytometry (FACSCalibur and by three functional MV assays: Zymuphen MP-activity in which data were given as phosphatidylserine equivalent, STA® Phospholipid Procoag Assay expressed as clotting time and Endogenous Thrombin Potential (ETP reflecting in vitro thrombin generation. Correlations were determined by Spearman correlation. Results: Absolute counts of lactadherin+ procoagulant MVs generated by flow cytometry weakly correlated with the results obtained from the Zymuphen MP-activity (r=0.5370, p<0.0001; correlated with ETP (r=0.7444, p<0.0001; negatively correlated with STA® Phospholipid Procoag Assay clotting time (?0.7872, p<0.0001, reflecting a positive correlation between clotting activity and flow cytometry. Levels of Annexin V+ procoagulant and platelet-derived MVs were also associated with functional assays. Absolute counts of MVs derived from other cell types were not correlated with the functional results. Conclusions: Quantitative results of procoagulant and platelet-derived MVs from conventional flow cytometry are associated with the functional capability of the MVs, as defined by three functional MV assays. Flow cytometry is a valuable technique for the quantification of MVs from different cellular origins; however, a combination of several analytical techniques may give the most comprehensive information on the role of MVs in health and disease.

  3. Absolute measurements of the /sup 115/In(n,?)/sup 116m1/In cross section for fast neutrons

    International Nuclear Information System (INIS)

    The neutron capture cross section in /sup 115/In leading to the 54.12 min isomeric state (m/sub 1/) in /sup 116/In has been absolutely determined at neutron energies of 23,265, and 964 keV. These energies are the median neutron energies of the three photoneutron sources, Sb-Be, Na-D, and Na-Be, applied in this work. The measurements are independent of other cross-section data except for corrections amounting to <10%. Reaction rates were determined by beta counting of the /sup 116mI/In decay activity using a 4? gas flow proportional counter. Detector efficiency was measured using 4? beta-gamma coincidence counting techniques, incorporating the foil absorber method of efficiency extrapolation for correction of complex decay scheme effects. Photoneutron source emission rates were determined by indirect comparison with the U.S. National Bureau of Standards NBS-II standard source in the University of Michigan Manganese Bath. The normalized scalar flux was calculated from the neutron emission angular distribution results of a Monte Carlo computer program used to model neutron and gamma transport in the source. Correction factors were applied related to competing reactions, neutron scattering from experiment components, background from room-return neutrons, and differences in the energy spectra of the neutron sources. The absolute cross-section values obtained for the /sup 115/In(n,?)/sup 116mI/In reaction were 588 +. 11, 196 +. 4, and 203 +. 4 mb at 23, 265, and 964 keV, respectively

  4. Effect of background radiation shielding on natural radioactivity distribution measurement with imaging plate

    International Nuclear Information System (INIS)

    Distribution images of natural radioactivity contained in various natural materials such as vegetable, animal meat and pottery work can be obtained with an imaging plate which has high sensitivity for nuclear radiations. For such very low levels of radioactivity, natural background radiations must be reduced using a shielding box. The lining, on the inside of the box, with low atomic number material such as acrylic resin is very effective in reducing electrons, ?-rays and low energy X- and ?-rays emitted from the inner surface of the shielding material. Some images of natural radioactivity distribution were obtained and the radioactivity, mainly 40K, contained in natural materials was measured by using an HPGe detector and also the imaging plate itself. (orig.)

  5. The Japan Power Demonstration Reactor decommissioning program. Decontamination and radioactivity measurement on building surfaces

    International Nuclear Information System (INIS)

    After dismantling the components in the facilities of Japan Power Demonstration Reactor (JPDR), decontamination on concrete surfaces and final survey of radioactivity have been started as the last step in the JPDR dismantling activities. At the first step for the decontamination on concrete surfaces and the final survey of radioactivity is as follows; The contamination on the concrete surfaces in the JPDR facility was characterized on the basis of radioactivity measurements of samples taken from the buildings. The contamination in the JPDR facility was categorized into two groups: fixed or removable; deep penetrative contamination was not found in the JPDR facility. The distribution map of the contamination was made based on the characterization. Decontamination activities were planned according to the distribution map of the contamination. The all buildings will be demolished and the site will be landscaped after finishing the final survey of radioactivity by March 1996. (author)

  6. Calibration of a gamma spectrometer for natural radioactivity measurement. Experimental measurements and Monte Carlo modelling

    International Nuclear Information System (INIS)

    The thesis proceeded in the context of dating by thermoluminescence. This method requires laboratory measurements of the natural radioactivity. For that purpose, we have been using a germanium spectrometer. To refine the calibration of this one, we modelled it by using a Monte-Carlo computer code: Geant4. We developed a geometrical model which takes into account the presence of inactive zones and zones of poor charge-collection within the germanium crystal. The parameters of the model were adjusted by comparison with experimental results obtained with a source of 137Cs. It appeared that the form of the inactive zones is less simple than is presented in the specialized literature. This model was widened to the case of a more complex source, with cascade effect and angular correlations between photons: the 60Co. Lastly, applied to extended sources, it gave correct results and allowed us to validate the simulation of matrix effect. (author)

  7. Absolute activity measurement and gamma-ray emission probability for decay of I-126

    International Nuclear Information System (INIS)

    The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of 126 I, its importance lies mainly in fast neutron dosimetry as well as in the production of 125 I where 126 I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of 126 I have been measured. This radionuclide was obtained by means of the 127 I(n, 2n)126 I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of 126 I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The ?branch measurement was carried out in a 4 ?(PC)?-? coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch was measured in a X-? coincidence system using two NaI(Tl) crystals. The gamma-ray measurements were performed in a HPGe system, previously calibrated by means of standard sources supplied by the International Atomic Energy Agency. All the uncertainties evolved were treated rigorously, by means of covariance analysis. (author)

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

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

    Ro?. 22, ?. 18 (2014), s. 21214-21226. ISSN 1094-4087 R&D Projects: GA MŠk(CZ) LG13029 Institutional support: RVO:68378271 Keywords : soft x-ray * free electron laser * LCLS * instrumentation * measurement * metrology Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.525, year: 2013

  9. LOWRAD 96. Methods and applications of low-level radioactivity measurements. Proceedings

    International Nuclear Information System (INIS)

    The newest developments in the field of low-level radioactivity measurements and new applications for existing and low-level measuring facilities are presented. The contributions mostly were devoted to basic physical aspects and applications of low-level counting. Papers on chemical separation and preparation techniques and on low-level radiation dose determinations were also presented. (DG)

  10. LOWRAD 96. Methods and applications of low-level radioactivity measurements. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Fietz, J. [ed.] [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany)

    1997-03-01

    The newest developments in the field of low-level radioactivity measurements and new applications for existing and low-level measuring facilities are presented. The contributions mostly were devoted to basic physical aspects and applications of low-level counting. Papers on chemical separation and preparation techniques and on low-level radiation dose determinations were also presented. (DG)

  11. Glossary concerning the measuring instructions for the envrionmental control of radioactive materials and external radiation

    International Nuclear Information System (INIS)

    The glossary is covering the technical terms used in the measuring instructions for radioactivity control published by the Federal Ministry for Environment, Nature Protection and Reactor Safety. The glossary includes definitions for the technical terms; the measuring units are explained and commented. The glossary is aimed to be used by journalists and scientific personnel.

  12. Calibration of HPGe gamma-ray detectors for measurement of radioactive noble gas sources

    International Nuclear Information System (INIS)

    Measurements of radioactive noble gases are routinely made with gamma-ray spectrometers. This work describes the calibration of high purity germanium detectors provided by the full-energy-peak efficiency as a function of the gamma-ray energy. A comparison of measured efficiency values with a new, simplified method based on a direct mathematical method is given here

  13. Study on residual radioactivity measurement method for site release of nuclear facilities. In-situ radioactivity measurement test with the use of portable Ge semiconductor detector (Contract research)

    International Nuclear Information System (INIS)

    Nuclear facility sites after decommissioning are allowed to be released from nuclear safety regulations after confirming that sites have been decontaminated to acceptable levels. In-situ measurement with the use of a portable pure-germanium semiconductor detector (Ge detector) is a suitable technology for confirmatory survey. A method to conservatively evaluate residual radioactivity on the sites was proposed in this study. In the evaluation method concept, the radionuclide (Cs-137, etc.), which are in reality distributed across the area of interest, is assumed to be the single point source located at the furthest position on the ground surface of the area from the Ge detector. Based on this assumption, the detectable minimum time of the interest radionuclide was predicted by the calculation. If radiation from the point source is not detected for longer than the predicted detectable time, it can be proven that the radioactivity remaining in the interest area is lower than the radioactivity corresponding to the assumed point source. Results of the field test in JAEA site indicated that the proposed evaluation method was reasonable for the conservative evaluation of residual radioactivity. (author)

  14. New Measurements of the Absolute Spectral Energy Distribution of Solar Radiation in the Range Double Lambda 650-1070 NM

    Science.gov (United States)

    Burlov-Vasilev, K. A.; Vasileva, I. E.; Matveev, Yu. B.

    1996-01-01

    Spectral measurements of the solar disk centre intensity for the near-IR region have been made at he Terskol High-Altitude Station in 1992. These measurements are the continuation of the program for the solar absolute spectral energy distribution investigation. Data published earlier are extended to the longwave spectral region up to 1070 nm. The special-purpose solar telescope SEF-1 was used. We compared the disk centre brightness with brightness of the calibrated region of the standard ribbon tungsten lamp. The atmospheric extinction was taken into account by the Bouguer method with simultaneous control of the atmosphere stability. The 1-nm integrals of the disk centre intensity in the range double lamda 650-1070 nm based on 5-day measurements in March-October 1992 are given. The uncertainty of these values is 2%. In regions with strong telluric absorption by oxygen and water-vapour bands, the reductions are made, using synthetic atmospheric absorption spectra computed on the basis of molecular parameter atlas HITRAN and the standard model atmosphere. By the use of the solar limb darkening coefficients the values of the solar flux at 1 A.U. were derived. Our measurements show the best agreement with the data of Makarova, Kharitonov, and Kazachevskaya as well as with the common data from Shaw and Frohlich. For lambda greater than 850 nm our data are systematically lower than the data by Neckel and Labs.

  15. Systematic Uncertainties in the Spectroscopic Measurements of Neutron-Star Masses and Radii from Thermonuclear X-ray Bursts. III. Absolute Flux Calibration

    OpenAIRE

    Guver, Tolga; Ozel, Feryal; Marshall, Herman; Psaltis, Dimitrios; Guainazzi, Matteo; Diaz-trigo, Maria

    2015-01-01

    Many techniques for measuring neutron star radii rely on absolute flux measurements in the X-rays. As a result, one of the fundamental uncertainties in these spectroscopic measurements arises from the absolute flux calibrations of the detectors being used. Using the stable X-ray burster, GS 1826-238, and its simultaneous observations by Chandra HETG/ACIS-S and RXTE/PCA as well as by XMM-Newton EPIC-pn and RXTE/PCA, we quantify the degree of uncertainty in the flux calibratio...

  16. Measurement of the Absolute Branching Fraction of D_s^+ --> tau^+ nu_tau Decay

    CERN Document Server

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

    2007-01-01

    Using a sample of tagged D_s decays collected near the D^*_s D_s peak production energy with the CLEO-c detector, we study the leptonic decay D^+_s to tau^+ nu_tau via the decay channel tau^+ to e^+ nu_e bar{nu}_tau. We measure B(D^+_s to tau^+ nu_tau) = (6.17 +- 0.71 +- 0.34) %. Combining with our measurements of D^+_s to mu^+ nu_mu and D^+_s to tau^+ nu_tau (via tau^+ to pi^+ bar{nu}_tau), we determine f_{D_s} = 274 +- 10 +- 5 MeV.

  17. Absolute measurement of thermal noise in a resonant short-range force experiment

    International Nuclear Information System (INIS)

    Planar, double-torsional oscillators are especially suitable for short-range macroscopic force search experiments, since they can be operated at the limit of instrumental thermal noise. As a study of this limit, we report a measurement of the noise kinetic energy of a polycrystalline tungsten oscillator in thermal equilibrium at room temperature. The fluctuations of the oscillator in a high-Q torsional mode with a resonance frequency near 1 kHz are detected with capacitive transducers coupled to a sensitive differential amplifier. The electronic processing is calibrated by means of a known electrostatic force and input from a finite-element model. The measured average kinetic energy, Eexp = (2.0 ± 0.3) × 10?21 J, is in agreement with the expected value of 1/2kBT. (paper)

  18. Flux depression and the absolute measurement of the thermal neutron flux density

    International Nuclear Information System (INIS)

    The thermal neutron flux depression in a diffusing medium by an absorbing foil has been treated in numerous papers. The results are re-examined in an attempt to find a uniform and physically meaningful representation of the 'activation correction'. This quantity can be split up into a combination of probabilities. Thus, it is possible to determine the activation correction for any moderator and foil material. Measurements confirm the utility of the concepts introduced

  19. Measurement of absolute auditory thresholds in the common marmoset (Callithrix jacchus)

    OpenAIRE

    Osmanski, Michael S.; Wang, Xiaoqin

    2011-01-01

    The common marmoset is a small, arboreal, New World primate that has emerged as a promising non-human model system in auditory neuroscience. A complete understanding of the neuroethology of auditory processing in marmosets will include behavioral work examining how sounds are perceived by these animals. However, there have been few studies of the marmoset’s hearing and perceptual abilities and the audiogram of this species has not been measured using modern psychophysical methods. The prese...

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

    OpenAIRE

    Vieland, V. J.; Das, J.; Hodge, S. E.; Seok, S. -c

    2013-01-01

    Statistical analysis is used throughout biomedical research and elsewhere to assess strength of evidence. We have previously argued that typical outcome statistics (including p-values and maximum likelihood ratios) have poor measure-theoretic properties: they can erroneously indicate decreasing evidence as data supporting an hypothesis accumulate; and they are not amenable to calibration, necessary for meaningful comparison of evidence across different study designs, data ty...

  1. A new method for measuring absolute total electron-impact cross sections with forward scattering corrections

    International Nuclear Information System (INIS)

    In this article we describe an experimental technique to measure the total electron-impact cross section by measurement of the attenuation of an electron beam passing through a gas at constant pressure with the unwanted forward scattering contribution removed. The technique is based on the different spatial propagation properties of scattered and unscattered electrons. The correction is accomplished by measuring the electron beam attenuation dependence on both the target gas pressure (number density) and transmission length. Two extended forms of the Beer--Lambert law which approximately include the contributions for forward scattering and for forward scattering plus multiple scattering from the gas outside the electron beam were developed. It is argued that the dependence of the forward scattering on the path length through the gas is approximately independent of the model used to describe it. The proposed methods were used to determine the total cross section and forward scattering contribution from argon (Ar) with 300-eV electrons. Our results are compared with those in the literature and the predictions of theory and experiment for the forward scattering and multiple scattering contributions. In addition, Monte Carlo simulations were performed as a further test of the method

  2. Absolute measurement of photon-flux using a multi-electrode ion chamber

    International Nuclear Information System (INIS)

    We measured photon flux using a multi-electrode ion chamber. These results were compared with photoemission measurements of photo-diode and Au. The experiment was carried out for photon energy of 487, 571, 688, 868 and 1078 eV at the soft-X ray beamline, BL23SU in the SPring-8. The ion chamber was supplied with Ar gas. A fitting calculation with consideration of secondary ionization by ejected electrons has reproduced plotting curves of experimental ion currents against gas density in the pressure region of 10-2 to 102 Pa. These results were from 2.07x1010 to 3.13x10ll photons/s as increasing with photon energy under the storage ring current of 100 mA. Although analytical results under 571 eV were consistent with those from measurement using a photo-diode within statistical error, the discrepancies between both results were larger as increasing the photon energy over 571 eV. The photon flux obtained at 1078 eV by using the photo-diode showed 33% smaller value comparing to that obtained from the ion chamber. (author)

  3. Measuring apparatus for monitoring radioactive noble gas discharge in nuclear power plants

    International Nuclear Information System (INIS)

    An equipment to measure radioactive noble gases emitted through the ventialtion stacks of nuclear power plants is described. It uses a semiconductor detector accommodated in a low-background measuring chamber. The data measured are processed with a CAMAC type multichannel analyzer and a microprocessor. Both sampling and measuring processes are fully automated. The results are shown on a colour display and recorded on punched tape. (author)

  4. Absolute time-of-arrival measurements of optical pulses from the Crab pulsar.

    Science.gov (United States)

    Papaliolios, C; Carleton, N P; Horowitz, P

    1970-10-31

    An attempt is made to understand the characteristics of pulsar slowdown in terms of various possible emission mechanisms. Though magnetic-dipole radiation seems to be dominant, the deviations from a pure dipolar decay are large compared with errors in measurement and indicate the presence of more complicated braking mechanisms, small fluctuations, and major "jumps", or period discontinuities. Some rapid-relaxation effect is evident following the discontinuous jump in period in September 1969, but there is no evidence of the quasi-sinusoidal behaviour reported before the jump by Arecibo. An alternative interpretation of the Arecibo data is given. PMID:16058540

  5. Absolute activity measurement and gamma-ray emission probability for decay of I-126

    CERN Document Server

    Fonseca, K A

    1997-01-01

    The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of sup 1 sup 2 sup 6 I, its importance lies mainly in fast neutron dosimetry as well as in the production of sup 1 sup 2 sup 5 I where sup 1 sup 2 sup 6 I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of sup 1 sup 2 sup 6 I have been measured. This radionuclide was obtained by means of the sup 1 sup 2 sup 7 I(n, 2n) sup 1 sup 2 sup 6 I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of sup 1 sup 2 sup 6 I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The beta branch measurement was carried out in a 4 pi(PC)beta-gamma coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch ...

  6. Results of radioactivity measurements along the french coasts during 1986

    International Nuclear Information System (INIS)

    A number of sampling networks for the environmental monitoring of levels from radioactive waste releases from french nuclear plants have been set up by the DPS/SEAPS since 1983. Various marine and freshwater biological indicators are being collected regularly on the Channel and Mediterranean shores and at the level of the lower Rhone river. Data gathered in 1986 show the prevailing effects of the releases from La Hague reprocessing plant and Rhone waters on the Channel and the Mediterranean sea respectively. However, clear labelling due to the CHERNOBYL accident on April 26 appeared in May and afterwards; this was shown by the appearance or level increase of different radionuclides such as: 137Cs, 134Cs, 131I, 110mAg, 106Ru, 103Ru. The sampling stations on the Mediterranean eastern shore were the most affected and the impact of CHERNOBYL was still present in December. At the most contaminated station, Nice, the health consequence, taking into account the annual maximum levels, led to a fraction of 8.10-5 of the dose limit (5 mSv.y-1) recommended by the International Commission on Radiological Protection

  7. Measurement of mean transit time with radioactive tracers

    International Nuclear Information System (INIS)

    The purpose of this work was to validate the use of moment to computer transit time in radioactive tracer studies. In tracer dilution studies, input and output functions usually can be described by means of exponential and gamma-variate functions. The authors demonstrated mathematically that computation of transit time with use of the first moments of these modeling functions is equivalent to the use of impulse response functions. They used a test object that would emulate the transit time of pulmonary blood flow in a medium-size dog to validate the computation of transit time with the first moment. A bolus of 185 MBq (5 mCi) of Tc-99m pertechnetate was injected. The quality of the bolus injection was modified by changing the size of the bolus. The transit time obtained from the first moments of the tracer-dilution curves was in agreement with the first moments of the modeling mathematical functions. Transit time is radionuclide studies can be computed from either the first moment of the tracer-dilution curve or of the modeling mathematical functions. Derivation of the impulse response function is not necessary

  8. Measurement of radioactivity in bottled drinking water in Spain

    International Nuclear Information System (INIS)

    The radioactive parameters in the Spanish regulations on water intended for human consumption (law decree 140/2003) have been determined in 30 different brands of some of the most common bottled mineral waters produced and consumed in Spain. These waters are not included in this legislation but if their consumption increases, the dose of radiation in the population may also increase. After gross alpha activity, gross beta activity, gross beta without potassium contribution and tritium activity had been determined, only a few samples (16% of the samples analysed) were over the normative limit for gross alpha activity (0.1 Bq/l), whereas all the samples were below the normative limits for the other parameters. For samples with high gross alpha activity values, 226Ra and 224Ra were determined. The values were between 0.01 and 1.52 Bq/l, and between 0.01 and 0.38 Bq/l, respectively, so alpha activity should be considered to be of natural origin

  9. Measurement of radioactivity in the environment - Soil - Part 3: Measurement of gamma-emitting radionuclides

    International Nuclear Information System (INIS)

    This part of ISO 18589 specifies the identification and the measurement of the activity in soils of a large number of gamma-emitting radionuclides using gamma spectrometry. This non-destructive method, applicable to large-volume samples (up to about 3 000 cm3), covers the determination in a single measurement of all the ?-emitters present for which the photon energy is between 5 keV and 3 MeV. This part of ISO 18589 can be applied by test laboratories performing routine radioactivity measurements as a majority of radionuclides is characterized by gamma-ray emission between 40 keV and 2 MeV. This part of ISO 18589 is suitable for the surveillance of the environment and the inspection of a site and allows, in case of accidents, a quick evaluation of gamma activity. Information is provided on scope, normative references, terms, definitions and symbols, principle, gamma-spectrometry equipment, sample container, procedure, expression of results and test report. Annex A reports on calculation of the activity per unit mass form a gamma spectrum using a linear background subtraction. Annex B reports on the Analysis of natural radionuclides in soil samples using gamma spectrometry. A bibliography is provided

  10. Measurement of the absolute total cross section for the reaction 7Li(d,p)8Li at low energies

    International Nuclear Information System (INIS)

    The total section for the reaction 7Li(d,p)8Li has been measured from 0.7 MeV to 3.4 MeV by the delayed counting of the beta-decay of the 8Li(T(1/2)=842 ms). The absolute cross section was determined by normalizing these data to the integrated angular distributions measured previously at six energies between 2.0 and 3.25 MeV for the reaction 7Li(d,p0)8Li (g.s.), taking into account the cross section for the reaction 7Li(d,p1)8Li*(0.98) above the threshold energy of 1.50 MeV. Comparison of these data with the previous six measurements of this cross section, which are in conflict, is discussed. A new value for the half-life of 8Li of 837 plus minus 3 ms is proposed

  11. Monitoring and measurements of radioactivity around the valley of Madjerdah river in Tunisia

    International Nuclear Information System (INIS)

    This paper discusses the efforts being made by the National Center for Nuclear Sciences and Technologies of Tunisia in cooperation with the Faculti des Sciences de Tunis to monitor the environmental radioactivity in soil and water around the valley of Madjerda. Preliminary results of the radioactivity measured in soil, water and grass samples from the northern region of Tunisia are given. Measurements are being taken on a continuous basis in order to accumulate a useful database on natural and possible man-made radionuclides found in the area. This information is necessary in order to monitor future nuclear activities and to have a baseline for comparison purposes

  12. Measurement of radioactive cesium fell on tsunami sludge in the east coast of Miyagi prefecture

    International Nuclear Information System (INIS)

    Tohoku coastal region facing Pacific Ocean covered with tsunami sludges when the Great East Japan Earthquake hit Japan, then soon radioactive materials caused by the Fukushima Daiichi nuclear power plant accident fell on there. During October and November 2011, the samples of tsunami sludge (0.005 - 0.17 m thickness) and paddy or upland soil covered by the tsunami sludge, were collected from 15 sites, and radioactivities were measured using automatic gamma counter. The maximum value of both 134Cs and 137Cs in tsunami sludges reached as much as 3500 Bq/kg, while the radioactive cesium in most soils ranged from about 1 to 31 Bq/kg. These results mean that most of radioactive cesium fell on Miyagi area stayed in the top layer (0 - 0.05 m depth). Moreover, extraction tests with a tsunami sludge having 2200 Bq/kg for both 134Cs and 137Cs showed that as much as 9% of radioactive cesium was released in ammonium oxalate (pH 3.0), while it was negligible in pure water (pH 7.0) or ammonium sulfate (pH 4.8). Thus, radioactive cesium strongly sorped in clay minerals, though six months have passed since the disaster, is not released just by rain (pH 5.6 - 7.0). (author)

  13. Direct Measurements of Absolute Branching Fractions for D0 and D+ Inclusive Semimuonic Decays

    CERN Document Server

    Ablikim, M; Bai, Y; Ban, Y; Cai, X; Chen, H F; Chen, H S; Chen, H X; Chen, J C; Jin Chen; Chen, X D; Chen, Y B; Chu, Y P; Dai, Y S; Deng, Z Y; Du, S X; Fang, J; Fu, C D; Gao, C S; Gao, Y N; Gu, S D; Gu, Y T; Guo, Y N; He, K L; He, M; Heng, Y K; Hou, J; Hu, H M; Hu, T; Huanga, G S; Huang, X T; Huang, Y P; Ji, X B; Jiang, X S; Jiao, J B; Jin, D P; Jin, S; Lai, Y F; Li, H B; Li, J; Li, R Y; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Liang, Y F; Liaob, H B; Liu, B J; Liu, C X; Fang, Liu; Feng, Liu; Liuc, H H; Liu, H M; Liud, J B; Liu, J P; Liu, H B; Liu, J; Liu, R G; Liu, S; Liu, Z A; Lu, F; Lu, G R; Lu, J G; Luo, C L; Ma, F C; Ma, H L; Mae, L L; Ma, Q M; Malik, M Q A; Mao, Z P; Mo, X H; Nie, J; Ping, R G; Qi, N D; Qin, H; Qiu, J F; Rong, G; Ruan, X D; Shan, L Y; Shang, L; Shen, D L; Shen, X Y; Sheng, H Y; Sun, H S; Sun, S S; Sun, Y Z; Sun, Z J; Tang, X; Tian, J P; Tong, G L; Wan, X; Wang, L; Wang, L L; Wang, L S; Wang, P; Wang, P L; Wangf, W F; Wang, Y F; Wang, Z; Wang, Z Y; Wei, C L; Wei, D H; Weng, Y; Wu, N; Xia, X M; Xie, X X; Xu, G F; Xu, X P; Xu, Y; Yan, M L; Yang, H X; Yang, M; Yang, Y X; Ye, M H; Ye, Y X; Yu, C X; Yu, G W; Yuan, C Z; Yuan, Y; Zangg, S L; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C C; Zhang, D H; Zhang, H Q; Zhang, H Y; Zhang, J W; Zhang, J Y; Zhang, X Y; Zhang, Y Y; Zhang, Z X; Zhang, Z P; Zhao, D X; Zhao, J W; Zhao, M G; Zhao, P P; Zheng, H Q; Zheng, J P; Zheng, Z P; Zhou, B; Zhong, L; Zhu, K J; Zhu, Q M; Zhu, X W; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhu, Z L; Zhuang, B A; Zou, B S

    2008-01-01

    By analyzing about 33 $\\rm pb^{-1}$ data sample collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we directly measure the branching fractions for the neutral and charged $D$ inclusive semimuonic decays to be $BF(D^0 \\to \\mu^+ X) =(6.8\\pm 1.5\\pm 0.7)%$ and $BF(D^+ \\to \\mu^+ X) =(17.6 \\pm 2.7 \\pm 1.8)%$, and determine the ratio of the two branching fractions to be $\\frac{BF(D^+ \\to \\mu^+ X)}{BF(D^0 \\to \\mu^+ X)}=2.59\\pm 0.70 \\pm 0.25$.

  14. The role of camera and illumination choices in absolute blood velocity measurements

    Science.gov (United States)

    Ramella-Roman, Jessica C.; Winhoven, S.

    2015-03-01

    Non-invasive measurements of blood velocity at the capillary level are of great interest in many clinical applications. Recently we presented a new method for the quantitative estimation of blood flow velocity, based on the use of the Radon transform. The technique was based on narrow band illumination at 525 nm and tracking of non-uniform distribution of red blood cells within the vessel, rather than the individual blood cells themselves. Here we present a complete error analysis of this useful technique, highlighting the role of camera and illumination choices. Finally we propose in vivo examples on retinal flow imaging and compare the results obtained with this technique to the one proposed by a commercial system.

  15. Direct measurement of the absolute absorption spectrum of individual semiconducting single-wall carbon nanotubes

    Science.gov (United States)

    Blancon, Jean-Christophe; Paillet, Matthieu; Tran, Huy Nam; Than, Xuan Tinh; Guebrou, Samuel Aberra; Ayari, Anthony; Miguel, Alfonso San; Phan, Ngoc-Minh; Zahab, Ahmed-Azmi; Sauvajol, Jean-Louis; Fatti, Natalia Del; Vallée, Fabrice

    2013-09-01

    The optical properties of single-wall carbon nanotubes are very promising for developing novel opto-electronic components and sensors with applications in many fields. Despite numerous studies performed using photoluminescence or Raman and Rayleigh scattering, knowledge of their optical response is still partial. Here we determine using spatial modulation spectroscopy, over a broad optical spectral range, the spectrum and amplitude of the absorption cross-section of individual semiconducting single-wall carbon nanotubes. These quantitative measurements permit determination of the oscillator strength of the different excitonic resonances and their dependencies on the excitonic transition and type of semiconducting nanotube. A non-resonant background is also identified and its cross-section comparable to the ideal graphene optical absorbance. Furthermore, investigation of the same single-wall nanotube either free standing or lying on a substrate shows large broadening of the excitonic resonances with increase of oscillator strength, as well as stark weakening of polarization-dependent antenna effects, due to nanotube-substrate interaction.

  16. Absolute beginners

    OpenAIRE

    Costa, Carlos Casimiro Da; Costa, Jacinta Casimiro Da

    2012-01-01

    Tomorrow, I m recovering my Thursday child as an absolute beginner , Transporting you to the essential touch of surface skin and space, Only for you, i do not regret, looking for education in a materia set. My love is your love , my materiality is you making things, The legacy of our ethnography, craftsmen s old and disappear, make me strong hard feelings, Recovering experiences and knowledge sprinkled in powder of stone, wood and metal ( ) reflecting in your dirty face the ...

  17. Daily measurements of natural and artificial radioactivity in 1960

    International Nuclear Information System (INIS)

    Daily numerical results of measures concerning ? activity of the air, either from natural, owing to thoron, or from artificial, owing to active aerosols origin, will be found in this statement. The all results are expressed in ??curie / m3 of air. Proceedings of measure and technic of standardization, which were the matter of anterior papers, have not been discussed once more here. (author)

  18. Internal Liquid Scintillation Counting Applied to the Absolute Disintegration-Rate Measurement of Electron Capture Nuclides

    International Nuclear Information System (INIS)

    The nuclides chronium-51, manganese-54, cobalt-57 and zinc-65 have been standardized by counting coincident radiation with a sodium iodide gamma scintillation counter, and an internal liquid scintillation counter containing the source in solution. Coincidence measurements were made at different values of X-ray plus Auger-electron counting efficiency. This variation of counting efficiency was obtained electronically by varying the amplification and/or the discrimination level. It is shown how a graph of X- plus Auger counting rate against the ratio C/G, where C and G are the coincidence and gamma counting rates, respectively, is a straight line which can be extrapolated accurately to give the disintegration rate of the source. This extrapolation corrects for complications caused by the gamma-ray contribution in the liquid scintillation detector. The standardization results were compared with coincidence counting of deposited sources in a conventional 4? proportional counter-gamma counter coincidence arrangement. The nuclides chronium-51, manganese-54 and zinc-65 were further used to establish a graph of counting efficiency against K X-ray energy. This could then be used to find the counting efficiency of the liquid scintillation counter for the pure electron capturing nuclide iron-55, and thus the disintegration rates of sources of this nuclide. The method demands that sources of the above mentioned nuclides be counted at least once under identical experimental condit once under identical experimental conditions. After the calibration curve has been obtained, however, it is only necessary to count samples of any one of the above gamma emitting nuclides together with the iron-55, either as internal or external standard, to obtain the disintegration rate of the iron-55 samples. Results are presented, illustrating the degree of precision and reproducibility obtained. (author)

  19. Report of results of environmental radioactivity measurement around nuclear power stations in fiscal year 1980

    International Nuclear Information System (INIS)

    In Fukushima Prefecture, the measurement of environmental radioactivity around the nuclear power stations installed or expected to be installed has been carried out since August, 1973. Also, Tokyo Electric Power Co., Inc., has carried out the measurement of environmental radioactivity in and around the Fukushima No. 1 Nuclear Power Station since February, 1968, and in and around the Fukushima No. 2 Nuclear Power Station since April, 1978. These results of measurement have been published every two months after having been evaluated and examined by the Fukushima Nuclear Power Station Security Technology Liaison Conference, and also in annual reports. In this fiscal year, surf clams were added to the fundamental plan of environmental radioactivity measurement as a new sample, based on the basic investigation of surf clams performed in the last year. In this report, the results of above mentioned measurement in fiscal year 1980 are summarized as the annual report. The radiation dose, total alpha and total beta (gamma) radioactivity concentrations were within the range of natural fluctuation. The nuclides originated from nuclear test fallout and nuclear power stations were detected in very small quantity. (Kako, I.)

  20. Risk analysis and protective measures for occupationally workers with technologically enhanced naturally occurring radioactive materials

    International Nuclear Information System (INIS)

    Naturally occurring radionuclides are present in many natural resources. Elevated concentrations of these radionuclides are often found in certain geological materials, namely igneous rocks and ores. Human activities that exploit these resources may lead to enhanced concentrations of radionuclides (often referred to as technologically enhanced naturally occurring radioactive material (TE-NORM). Enhanced levels of natural background radiation are encountered in many occupational industrial activities involving a large number of workers. Uncontrolled activities associated with TE-NORM can contaminate the environment and pose a risk to human health. This risk can be alleviated by the adoption of controls to identify where NORM is present; and cleaning the NORM-contaminated equipment and waste management while protecting workers. The main objective of this study is to investigate the natural radioactivity and the hazard parameters in the TE-NORM samples from different industrial activities. Also to describe the models and develop the computer codes that allow one to estimate the risk of cancer resulting from any specified dose of ionizing radiation for occupationally workers in different industrial activities. The present study deals with 50 different samples. This waste generated from petroleum fields, phosphate fertilizers samples, consumer product samples from China, ceramic and zircon samples. The radon exhalation rates calculated using solid state nuclear track detector (CR-39). The value of radon exhalation rate 58.82±5.3 x103, 4.28±0.49 x103 and 0.306±0.025 x103 Bq/m2 h for scale, sludge and sand, respectively. The value of radon exhalation rate 82.67±7.98, 62.58 ±5.7, 46.16 ±3.91 and 198.51±18.68 Bq/m2 h for phosphate fertilizers samples, consumer product samples from China, ceramic and zircon samples, respectively. The 226Ra activity concentrations were 301.4±771.5, 52.1±438 and 2.56±55.37 kBq/kg for scale, sludge and sand, respectively. The 226Ra activity concentrations were 758.77±23.3, 744.47±57.4, 417.1±25.4 and 18317.4±26.9 Bq/kg for phosphate fertilizers samples, consumer product samples from China, ceramic and zircon samples, respectively.The average activity concentrations of 238U, 232Th and 40K for TE-NORM samples are higher than the world wide average value. The worldwide average values (32, 35, 45 and 420) for 226R, 238U series, 232Th series and 40K, respectively. The estimated hazard parameters in all TE-NORM samples are higher than the recommended values. The estimated average annual effective dose for both scale and sludge petroleum samples is higher than the recommended limits for occupationally worker while for the rest TE-NORM samples under investigation it is lower than the recommended values for workers. The excess relative risk and excess absolute risk of cancer are computed by special computer codes which developed for this study and tested. The obtained results proved that the workers with TENORM, in particular of oil activities, are under inevitable threat of cancer. They should be classified as occupationally radiation workers. In this study the general principles of radiation protection are primarily implemented by means of good protective measures at the workplaces. Hence, exposure control and adequate dosimetry assessment are the most critical components of a health and safety program.

  1. Precision mass measurements at TITAN with radioactive ions

    International Nuclear Information System (INIS)

    Highlights: • The TITAN facility is the sole online Penning trap mass spectrometer with charge breeding capabilities. • Use of highly charged exotic ions reduces the beam time requirements. • Threshold charge breeding was developed as a novel technique to separate isobaric species. • Recent mass measurements have been performed to investigate nuclear structure, tests of electroweak theory, and neutrino physics. -- Abstract: Measurements of the atomic mass further our understanding in many disciplines from metrology to physics beyond the standard model. The accuracy and precision of Penning trap mass spectrometry have been well demonstrated at TITAN, including measurements of neutron-rich calcium and potassium isotopes to investigate three-body forces in nuclear structure and within the island of inversion to study the mechanism of shell quenching and deformation. By charge breeding ions, TITAN has enhanced the precision of the measurement technique. The precision achieved in the measurement of the superallowed ?-emitter 74Rb in the 8+ charge state rivaled earlier measurements with singly charged ions in a fraction of the time. By breeding 78Rb to the same charge state, the ground state could be easily distinguished from the isomer. Further developments led to threshold charge breeding, which permitted capturing and measuring isobarically and elementally pure ion samples in the Penning trap. This was demonstrated via the Q-value determination of 71Ge. An overview of the TITAN facility and recent results are presented herein

  2. Absolute measurement of 235U fission cross section induced by 14.2 MeV neutrons

    International Nuclear Information System (INIS)

    Absolute measurement of the fission cross section of 235U induced by 14.2 MeV neutrons is performed by the time correlated associated particle method. The reaction T(d,n)He is used as neutron source. The deuteron beam of 220 keV is produced from the Cockcroft-walton generator. The associated alpha particles are detected by a thin plastic scintillator positioned at angle 90 deg with respect to the incident deuteron beam. The fission detector is an ionization chamber of fast current type. The timing distribution between the alpha particles and fission events is measured with the pulses from the fission chamber and the alpha particle detector as start and stop signals respectively for a TAC. Corrections are made for the effects such as efficiency of fission detector, neutron attenuation in samples and fission events due to other isotopes in the samples. The result obtained is (2.078±0.040)x10-28m2. Comparisons with the data of the other autors are also given

  3. A needle gas counter for measurements of low beta radioactivity of solid emitters

    International Nuclear Information System (INIS)

    An arrangement comprising a needle gas counter for measuring the low beta activity of solid emitters is described. Characteristics and experimental as well as theoretical results of the gas amplification are given with the counter working in conditions of deep reduced proportionality. A detection efficiency of 100 and 85 per cent in samples of 10 and 16 mm, respectively, is reached with a background of 0.04 cpm. Radioactivity measurements of lead and half-live measurements of 87Rb are reported

  4. Characteristic limits in radioactivity measurement. From Currie's definition to the international standard ISO-11929 publication

    International Nuclear Information System (INIS)

    Different approaches are found in the literature to compute the characteristics limits used to decide whether an activity measurement result for a radionuclide is significantly above the background level for the analyte in the sample. Comparing the different working expressions of the characteristic limits (critical level and detection limit) that can be used by any measurement laboratory; this paper shows that they are similar under the routine conditions of a majority of radioactivity measurement laboratories. (author)

  5. Comparison of filter papers and an electrostatic precipitator for measurements on radioactive aerosols

    International Nuclear Information System (INIS)

    Measurements in which electrostatic precipitators have been compared with filter papers for collection of air-borne radioactivity as to the accuracy in alpha and beta measurements have been made. The results show that the filter paper method is as good as the electrostatic method in determining beta-activity disregarding clogging and moisture sensitivity of the filter paper but it is inferior for alpha measurements. Experimental values of the alpha absorption factor for different types of filter papers are given

  6. Efficiency and production yield measurements of radioactive O, N and F for the spiral facility

    International Nuclear Information System (INIS)

    Production efficiencies of radioactive oxygen and nitrogen beams for the SPIRAL target-source system, measured at GANIL on the SIRa test bench, are presented. From the overall efficiency of oxygen, the product between the efficiency of transformation of O into CO and the effusion of CO from the target to the ion source, was deduced. The production yield measurements of oxygen and nitrogen isotopes performed on the SIRa test bench and those of fluorine directly measured on the SPIRAL facility are presented

  7. Multidetector-array adapter for residual radioactivity measurements

    International Nuclear Information System (INIS)

    A multidetector gamma-ray residual radioactivity system demands the development of a specific adapter to count coincidence events efficiently. The parameters to be acquired are gamma-ray energies and detection time intervals between pairs of detectors obtained through Analogue to Digital Converters (ADC) and Time Interval to Digital Converter (TDC), respectively. The data acquisition trigger must be generated internally because no external trigger, like that provided by the beam or the reaction in on-line multidetector systems, is available. The adapter that we developed intercepts the fast NIM time analogue and logical (busy and inhibit) signals from the spectroscopy amplifier and, after appropriate processing, controls the ADCs gates and generates start/stop signals for the TDC (8 input). The module implements a multilevel trigger system, each deeper level corresponding to a refined coincidence test, driven by a simple finite-state machine. The first level trigger corresponds to the detection of gamma-rays by at least two detectors in a 200 ns time window. This trigger signal, however, is not suitable to start the TDC since it is simultaneous to the last time signal. The TDC is started by the first of the time signals delayed by 200 ns in coincidence with the first level trigger. The second-level trigger consists of a majority coincidence, n > 1, of the linear amplifier busy signals with pile-up rejection, where only the detectors that triggered the adapter are takeectors that triggered the adapter are taken into account. The end of conversion of all digitizers pulls the third-level trigger, causing the data acquisition to start. The logic circuits are implemented by GALs (Generic Array Logic), and delays and time coincidence windows by fast transistors. All the circuits are placed in a single printed board, although the module occupies 4 CAMAC slots due to the large number of connectors in the front panel. The ADCs controlled by this system allow to obtain energy spectra like the usual gamma coincidence ones and, in spite of the time spectra obtained by the TDC being complex, the time difference spectra of a pair of detectors is similar to that obtained by time to pulse height converters. When tested with three large volume HPGe detectors, the energy gated time resolution was 5 ns. (author)

  8. Daily measurements of natural and artificial radioactivity in 1961 (1962)

    International Nuclear Information System (INIS)

    Daily numerical results of measures concerning ? activity of the air, either from natural, owing to thorium, or from artificial, owing to active aerosols origin, will be found in this statement. The all results are expressed in pico curie/m3 of air. Proceedings of measure and techniques of standardization, which were the matter of anterior papers, have not been discussed once more here. (author)

  9. Precision mass measurements at TITAN with radioactive ions

    Science.gov (United States)

    Kwiatkowski, A. A.; Macdonald, T. D.; Andreoiu, C.; Bale, J. C.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Ettenauer, S.; Gallant, A. T.; Grossheim, A.; Lennarz, A.; Mané, E.; Pearson, M. R.; Schultz, B. E.; Simon, M. C.; Simon, V. V.; Dilling, J.

    2013-12-01

    Measurements of the atomic mass further our understanding in many disciplines from metrology to physics beyond the standard model. The accuracy and precision of Penning trap mass spectrometry have been well demonstrated at TITAN, including measurements of neutron-rich calcium and potassium isotopes to investigate three-body forces in nuclear structure and within the island of inversion to study the mechanism of shell quenching and deformation. By charge breeding ions, TITAN has enhanced the precision of the measurement technique. The precision achieved in the measurement of the superallowed ?-emitter 74Rb in the 8+ charge state rivaled earlier measurements with singly charged ions in a fraction of the time. By breeding 78Rb to the same charge state, the ground state could be easily distinguished from the isomer. Further developments led to threshold charge breeding, which permitted capturing and measuring isobarically and elementally pure ion samples in the Penning trap. This was demonstrated via the Q-value determination of 71Ge. An overview of the TITAN facility and recent results are presented herein.

  10. PC based system for absolute neutron flux-spectrum measurements. Final report for the period 1 April 1994 - 15 December 1997

    International Nuclear Information System (INIS)

    When measuring absolute neutron flux-spectra, thin detector foils are irradiated in a neutron field. The absolute activity of isotopes generated by activation or fission reactions (fission products) is then measured, using an efficiency calibrated high resolution gamma-ray spectroscopy system, and the absolute reaction rates for their production is determined. Finally the flux-spectrum is determined based upon the reaction rate values. A general method to obtain flux-spectra from the reaction rate is the unfolding method. The above process involves computations of photopeak area, reaction rate, flux perturbation corrections and flux-spectrum. The PC's are well suited for the data processing system outlined above. Using available interfaces, the PC's can be involved even in the data acquisition. Graphical facilities allow decision upon the data processing flow

  11. Quality audit programme for 99mTc and 131I radioactivity measurements with radionuclide calibrators

    International Nuclear Information System (INIS)

    The use of radiopharmaceuticals in nuclear medicine for diagnosis and therapy has increased over the years with 99mTc and 131I being most widely used. Quality audit programmes for radioactivity measurements of 131I have been ongoing and the 12th audit was recently conducted among seventy nuclear medicine centres (NMC) in India. An audit for the activity measurements of 99mTc was conducted for the first time among ten NMCs in Mumbai, India. These programmes for radioactivity measurements have become very important to establish traceability of measurements to national and international standards and ensure accurate calibration of radionuclide calibrators. The results of both the audits are very encouraging. Ninety-four percent of the NMCs for 131I activity measurements were within a window of ±10% and for 99mTc one NMC was deviating more than ±10%. The methodology adopted for the audit and results are discussed in detail in this paper

  12. Surveillance of radioactivity in the atmosphere by measurements and dispersion prognosis of the German meteorological service

    International Nuclear Information System (INIS)

    Based on the Strahlenschutzvorsorgegesetz (StrVG) [Precautionary Radiological Protection Act] the Deutscher Wetterdienst (DWD) [German Meteorological Service] is responsible for the measurement of radioactivity in the atmosphere as well as for dispersion prognoses. By means of the communication-network used by the Deutscher Wetterdienst and the computer-network at the Central Office at Offenbach the measured data of 40 locations are summarized and transferred to the computer-network of the 'Integriertes Mess- und Informationssystem zur Ueberwachung der Umweltradioaktivitaet' (IMIS) [Integrated Measurement and Information System for the Surveillance of Environmental Radioactivity]. The dispersion prognosis as well as the measurement data are used as first input to calculate the radiological situation. The measurement programs and the resulting products of DWD are scheduled as well as the integration of DWD in the environmental emergency response program of the World Organisation of Meteorology (WMO). (orig.)

  13. The BiPo detector for ultralow radioactivity measurements

    CERN Document Server

    ,

    2011-01-01

    The development of BiPo detectors is dedicated to the measurement of extremely high radiopurity in 208Tl and 214Bi for the SuperNEMO double beta decay source foils. A modular prototype, called BiPo-1, with 0.8 m2 of sensitive surface area, has been running in the Modane Underground Laboratory since February, 2008. The goal of BiPo-1 is to measure the different components of the background and in particular the surface radiopurity of the plastic scintillators that make up the detector. The first phase of data collection has been dedicated to the measurement of the radiopurity in 208Tl. After more than one year of background measurement, a surface activity of the scintillators of A(208Tl) = 1.5 \\muBq/m2 is reported here. Given this level of background, a larger BiPo3 detector having 3.25 m2 of active surface area, will able to qualify the radiopurity of the SuperNEMO selenium double beta decay foils with the required sensitivity of A(208Tl) < 3-4 \\mu Bq/kg (90% C.L.) with a six month measurement. This detect...

  14. Measurement of the dry deposition rates on trees by using the natural radioactivity as a tracer

    International Nuclear Information System (INIS)

    Measurement of the dry deposition rates on trees by using the natural radioactivity as a tracer. The direct measurement of dry deposition fluxes into a canopy or onto single branches or leaves is difficult. The natural particle bound radioactivity in the ground-level air can be used as a tracer to gain information on this process in small scales of time and space. ?- and ?-spectroscopy of radioactive daughters of Rn and Tn deposited on filters and on leaves, needles and surrogate acceptors have been developed as highly mobile field-methods. Applying Radon daughters as tracers leads to information on deposition velocities during short time intervals. The evaluation of meteorological effects in the field thus becomes possible. The main factors influencing the deposition velocity are the particle size and the wind speed. Therefore size fractionating sampling devices and anemometer arrangements are needed, both small, light-weight and cheap. We prefered filter and impactor combinations to gain 4 size fractions suitable for radioactivity and composition measurements. The concentration values of compounds and elements have been evaluated by X-ray fluorescence and ionchromatography. Numerous results of measurements on natural leaves and surrogates are presented, showing the state of developement now attained and proving the applicability of this method. (orig.). 41 figs., 108 refs., 28 tabs

  15. Measures against illicit trafficking of nuclear materials and other radioactive sources in Nigeria

    International Nuclear Information System (INIS)

    The paper provides background information on the appropriate measures taken against illicit trafficking of nuclear materials and other radioactive sources in Nigeria. Organizational structure, manpower training and development, and the provision of adequate and necessary facilities and infrastructure for nationwide radiation monitoring programme are discussed in the paper. In conclusion, problem areas and areas where assistance are sort from the Agency were highlighted. (author)

  16. Absolute radiation detector

    Science.gov (United States)

    Martin, John E.

    1996-11-01

    An absolute radiation detector (a cryogenic radiometer) is being developed to replace the existing UK primary national standard cryogenic radiometer with an improved uncertainty. The cryogenic radiometer will be capable of measuring black body radiation and laser radiation with an uncertainty approaching 10 ppm. From these measurements it will be possible to determine the fundamental constant, the Stefan Boltzmann constant, confirming the radiometer as an absolute detector, and link this determination to the SI unit of luminous intensity, the candela. Thus detector and source based scales/standards will be tied to an invariant physical quantity ensuring their long-term stability.

  17. Requirements on radioactive wastes to be disposed and measures for product control of radioactive wastes - Morsleben repository for radioactive wastes (ERAM) - as of November 1992

    International Nuclear Information System (INIS)

    The waste categories 'solid wastes' and 'sealed sources' can be emplaced in the Morsleben repository (ERAM). The requirements on the wastes to be disposed of must be fulfilled by the waste producer upon delivery of the wastes. Concerning solid wastes, requirements on the waste forms and activity limitations for radionuclides and radionuclide groups must be fulfilled. Furthermore, requirements on packagings must be kept. Concerning sealed sources, basic requirements must be fulfilled and activity limitations depending on their packaging must be kept. Some radionuclides contained in the wastes must be indicated. The fulfilment of the requirements on radioactive wastes to be disposed of is proved within the framework of the waste package quality control. Organizational and administrative regulations and the check and control measures performed within the framework of the waste package quality control are described. The fulfilment of the requirements is proved by the qualification of conditioning procedures and following independent control measures performed during conditioning or by a random sampling inspection of waste packages. Furthermore, independent control measures at waste containers are performed. (orig.)

  18. Borehole-to-tunnel seismic measurements for monitoring radioactive waste

    Science.gov (United States)

    Manukyan, Edgar; Maurer, Hansruedi; Marelli, Stefano; Greenhalgh, Stewart A.; Green, Alan A.

    2010-05-01

    Countries worldwide are seeking solutions for the permanent removal of high-level radioactive waste (HLRW) from the environment. A critical aspect of the disposal process is the need to be confident that the deposited waste is safely isolated from the biosphere. Seismic monitoring represents a potentially powerful option for non-intrusive monitoring. We conducted a series of seismic experiments in the Mont Terri underground rock laboratory, where a 1-m-diameter microtunnel simulates a HLRW repository downsized by a factor of ~2.5. The host rock at the laboratory is Opalinus clay. We had access to two water-filled boreholes, each approximately 25 m long (diameter 85 mm), with one inclined upwards and the other downwards. Both were oriented perpendicular to the microtunnel axis. Seismic signals were generated in the down-dipping borehole with a high frequency P-wave sparker source every 25 cm and received every 25 cm in the upward-dipping borehole on a multi-channel hydrophone chain. Additionally, the seismic waves were recorded on eight (100 Hz natural frequency) vertical-component geophones, mounted and distributed around the circumference of the microtunnel wall within the plane of the boreholes. The experiment was repeated with different material filling the microtunnel and under different physical conditions. So far, six experiments have been performed when the microtunnel was: a. air-filled with a dry excavation damage zone (EDZ), b. dry sand-filled with a dry EDZ, c. 50 % water-saturated sand-filled with partially water-saturated EDZ (experiments were conducted immediately after half water-saturation), d. water-saturated sand-filled with partially water-saturated EDZ (immediately after full water-saturation), e. water-saturated sand-filled with water-saturated EDZ (water was in the microtunnel for about 9.5 months), and f. water-saturated sand-filled and pressurized to 6 bars with water-saturated EDZ. The results of our seismic experiments yield several important conclusions. 1) Travel time inversion of cross-hole data is not able to detect the microtunnel. This is due to the small size and central location of the microtunnel. Consequently, waveform inversions need to be performed. 2) The geophone recordings around the periphery of the tunnel are strongly affected by changes within the microtunnel. For example, between the individual experiments there are changes in the polarity of the first arriving waves for some of the geophones. This is because the recorded wavefield is a superposition of two waves. One wave passes directly through the microtunnel and is, therefore, influenced by the fill material. The other wave is diffracted around the microtunnel and is thus influenced primarily by the EDZ. The first wave to arrive depends on the geophone location (top, bottom, side of tunnel) as well as the state of the microtunnel and its EDZ. 3) Water infiltration changes the elastic properties of the microtunnel very rapidly. Repeated shots within 30-40 minutes intervals show significant waveform changes for some of the geophones during experiments (c) and (d). 4) Water infiltration changes the coupling conditions of the geophones significantly. For experiment (d), the frequency content on some geophone traces decreases significantly, and there is a remarkable increase of higher frequencies for experiments (e) and (f). This is due to the clay-water interaction, which first weakens the clay and thus loosens the geophone anchorage. Later, the water penetrating into the EDZ leads to swelling of the clay, which firmly fixes the geophones. 5) Analyses of the geophones installed within the microtunnel allow elastic properties of the EDZ to be delineated. A simple analysis of the first-arrival traveltimes allows us to determine a relationship between some properties of the EDZ (elasticity, radius).

  19. Radioactive Contamination Estimation from Micro-Copters or Helicopter Airborne Survey: Simulation and Real Measurements

    International Nuclear Information System (INIS)

    One of the main advantages of acquiring aero-radiometric measurements lies in the high collection rate of data over large areas and rough terrain. Typical aero-radiometric system records and saves gamma ray spectrum, correlated with the GPS derived location information in regular time intervals of one to two seconds. Such data can be used to locate radiation anomalies on the ground, map ground contamination or track a radioactive airborne plume. Acquiring spectral data of this type allows separation of natural radioactivity from that of man-made sources and identification of specific isotopes, natural or man-made

  20. Ordinance on the body responsible for taking measures in case of increased radioactivity (OROIR)

    International Nuclear Information System (INIS)

    This Ordinance, based on atomic energy legislation, public safety, military organisation and the defense council, replaced a previous ordinance of 1966 on alert in case of increased radioactivity. It sets up the body responsible for this work and describes the tasks to be performed in case of an occurrence which could create hazards for the population due to increased radioactivity. If a Swiss nuclear installation creates such a hazard, the 1982 Ordinance on emergency measures in the neighbourhood of nuclear installations also applies. The Ordinance entered into force on 1 May 1987 (NEA)