WorldWideScience

Sample records for beta delayed particle

  1. News on $\\beta$-delayed particle emission from $^{14}$Be

    CERN Document Server

    Jeppesen, H; Borge, M J G; Cederkäll, J; Fynbo, H O U; Fedoseyev, V N; Hansper, V Y; Jonson, B; Markenroth, K; Mishin, V I; Nilsson, T; Nyman, G; Riisager, K; Tengblad, O; Wilhelmsen Rolander, K

    2002-01-01

    $\\beta$-delayed charged particles from $^{14}$Be have been measured and give an upper limit on $\\beta$-delayed $\\alpha$-particles of B($\\beta\\alpha$) < $\\,6.7\\times\\!10^{-5}$ and a tentative branching ratio on $\\beta$-delayed tritons of $7.5\\times\\!10^{-5}$ < B($\\beta$t) < $\\,3.9\\times\\!10^{-4}$. We combine the knowledge on $\\beta$-delayed particles from $^{14}$Be to deduce information on the $\\beta$-strength distribution.

  2. A Further Measurement of the beta-Delayed alpha-Particle Emission of 16N

    CERN Document Server

    III, R H F; McDonald, J E; Wilds, E L

    2007-01-01

    We measured the beta-delayed alpha-particle emission spectrum of 16N with a sensitivity for beta-decay branching ratios of the order of 10-10. The 16N nuclei were produced using the d(15N,16N)p reaction with 70 MeV 15N beams and a deuterium gas target 7.5 cm long at a pressure of 1250 torr. The 16N nuclei were collected (over 10 s) using a thin aluminum foil with an areal density of 180 mu g/cm2 tilted at 7 Deg with respect to the beam. The activity was transferred to the counting area by means of a stepping motor in less than 3 s with the counting carried out over 8 s. The beta-delayed alpha-particles were measured using a time of flight method to achieve a sufficiently low background. Standard calibration sources (148Gd, 241Am, 208,209Po, and 227Ac) as well as alpha-particles and 7Li from the 10B(n,alpha)7Li reaction were used for an accurate energy calibration. The energy resolution of the catcher foil (180-220 keV) was calculated and the time of flight resolution (3-10 nsec) was measured using the beta-de...

  3. Particle unstable excited states in 9Be: Influence of beta recoil and width on delayed particle spectra

    International Nuclear Information System (INIS)

    The light nucleus 9Be has been studied through the emission of beta-delayed neutrons and alpha particles from 9Li. The activity was produced at the ISOLDE facility in fragmentation reactions induced either by 600 MeV proton or 910 MeV 3He beams from the CERN Synchro-cyclotron. After mass separation, neutron spectra were recorded using 3He-filled proportional counters, while surface barriere detectors were used for the spectroscopy of alpha particles. Effects on the spectrum shape induced by recoil and polarization phenomena as well as large widths of the intermediate states are discussed. (orig.)

  4. $\\beta$-delayed $\\gamma$-proton decay in $^{56}$Zn: analysis of the charged-particle spectrum

    CERN Document Server

    Orrigo, S E A; Fujita, Y; Blank, B; Gelletly, W; Agramunt, J; Algora, A; Ascher, P; Bilgier, B; Cáceres, L; Cakirli, R B; Fujita, H; Ganioglu, E; Gerbaux, M; Giovinazzo, J; Grévy, S; Kamalou, O; Kozer, H C; Kucuk, L; Kurtukian-Nieto, T; Molina, F; Popescu, L; Rogers, A M; Susoy, G; Stodel, C; Suzuki, T; Tamii, A; Thomas, J C

    2015-01-01

    A study of the $\\beta$ decay of the proton-rich $T_{z}$ = -2 nucleus $^{56}$Zn has been reported in a recent publication. A rare and exotic decay mode, $\\beta$-delayed $\\gamma$-proton decay, has been observed there for the first time in the $fp$ shell. Here we expand on some of the details of the data analysis, focussing on the charged particle spectrum.

  5. Systematic trends in beta-delayed particle emitting nuclei: The case of βpα emission from 21Mg

    Directory of Open Access Journals (Sweden)

    M.V. Lund

    2015-11-01

    Full Text Available We have observed β+-delayed α and pα emission from the proton-rich nucleus 21Mg produced at the ISOLDE facility at CERN. The assignments were cross-checked with a time distribution analysis. This is the third identified case of βpα emission. We discuss the systematic of beta-delayed particle emission decays, show that our observed decays fit naturally into the existing pattern, and argue that the patterns are to a large extent caused by odd–even effects.

  6. Beta-delayed particle emission from neutron-deficient tellurium, iodine, xenon, cesium and barium isotopes

    International Nuclear Information System (INIS)

    Using 58Ni, 63Cu(58Ni, xp yn) reactions and on-line mass separation the β-delayed proton and α-particle emission from neutron-deficient isotopes with 52113Xe, (protons), 114Cs (protons and α-particles) and 117Ba (protons). Coincidences between positons and β-delayed protons were recorded for 113Xe and 114Cs, yielding Qsub(EC)-Ssub(p) values of 7.92(15) and 8.73(15) MeV, respectively. The results are discussed within the statistical model. (orig.)

  7. Study of the $\\beta$-delayed Particle Emission of $^{17}$Ne

    CERN Multimedia

    2002-01-01

    We intend to investigate the charged particle decay modes from the excited states of $^{17}$F populated in the $\\beta^+$- decay of $^{17}$Ne. In particular, we propose to study the proton decay branches to $^{16}$O states which are unstable to $\\alpha$- decay. We plan to use the recently developed ISOLDE Si-ball detector array in order to efficiently detect the charged particles in a wide solid angle. We ask for a total of 12 shifts, including 9 shifts for $^{17}$Ne and 3 shifts for stable beam and calibrations. We request the use of a Mg oxide target coupled to a plasma ion source with cooled transfer line or, if possible, to the new MINIMONOECRIS. We would like to make use of the ISOLDE VME DAQ and CERN data storage system.

  8. Beta-delayed proton emission from $^{21}$Mg

    CERN Document Server

    Lund, M V; Briz, J A; Cederkäll, J; Fynbo, H O U; Jensen, J H; Jonson, B; Laursen, K L; Nilsson, T; Perea, A; Pesudo, V; Riisager, K; Tengblad, O

    2015-01-01

    Beta-delayed proton emission from $^{21}$Mg has been measured at ISOLDE, CERN, with a detection setup including particle identification capabilities. $\\beta$-delayed protons with center of mass energies between 0.39$\\,$MeV and 7.2$\\,$MeV were measured and used to determine the half life of $^{21}$Mg as $118.6\\pm 0.5\\,$ms. From a line shape fit of the $\\beta p$ branches we extract spectroscopic information about the resonances of $^{21}$Na. Finally an improved interpretation of the decay scheme in accordance with the results obtained in reaction studies is presented.

  9. Improvements to the on-line mass separator, RAMA, and the beta-delayed charged-particle emission of proton-rich sd shell nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ognibene, T.J. [Lawrence Berkeley National Lab., CA (United States). Nuclear Science Div.

    1996-03-01

    To overcome the extreme difficulties encountered in the experimental decay studies of proton drip line nuclei, several techniques have been utilized, including a helium-jet transport system, particle identification detectors and mass separation. Improvements to the ion source/extraction region of the He-jet coupled on-line Recoil Atom Mass Analyzer (RAMA) and its target/ion source coupling resulted in significant increases in RAMA efficiencies and its mass resolution, as well as reductions in the overall transit time. At the 88-Inch Cyclotron at LBNL, the decays of {sup 31}Cl, {sup 27}P and {sup 28}P, with half-lives of 150 msec, 260 msec and 270.3 msec, respectively, were examined using a he-jet and low-energy gas {Delta}E-gas {Delta}E-silicon E detector telescopes. Total beta-delayed proton branches of 0.3% and 0.07% in {sup 31}Cl and {sub 27}P, respectively, were estimated. Several proton peaks that had been previously assigned to the decay of {sup 31}Cl were shown to be from the decay of {sup 25}Si. In {sup 27}P, two proton groups at 459 {+-} 14 keV and 610 {+-} 11 keV, with intensities of 7 {+-} 3% and 92 {+-} 4% relative to the main (100%) group were discovered. The Gamow-Teller component of the preceding beta-decay of each observed proton transition was compared to results from shell model calculations. Finally, a new proton transition was identified, following the {beta}-decay of {sup 28}P, at 1,444 {+-} 12 keV with a 1.7 {+-} 0.5% relative intensity to the 100% group. Using similar low-energy detector telescopes and the mass separator TISOL at TRIUMF, the 109 msec and 173 msec activities, {sup 17}Ne and {sup 33}Ar, were studied. A new proton group with energy 729 {+-} 15 keV was observed following the beta-decay of {sup 17}Ne. Several discrepancies between earlier works as to the energies, intensities and assignments of several proton transitions from {sup 17}Ne and {sup 33}Ar were resolved.

  10. Improvements to the on-line mass separator, RAMA, and the beta-delayed charged-particle emission of proton-rich sd shell nuclei

    International Nuclear Information System (INIS)

    To overcome the extreme difficulties encountered in the experimental decay studies of proton drip line nuclei, several techniques have been utilized, including a helium-jet transport system, particle identification detectors and mass separation. Improvements to the ion source/extraction region of the He-jet coupled on-line Recoil Atom Mass Analyzer (RAMA) and its target/ion source coupling resulted in significant increases in RAMA efficiencies and its mass resolution, as well as reductions in the overall transit time. At the 88-Inch Cyclotron at LBNL, the decays of 31Cl, 27P and 28P, with half-lives of 150 msec, 260 msec and 270.3 msec, respectively, were examined using a he-jet and low-energy gas ΔE-gas ΔE-silicon E detector telescopes. Total beta-delayed proton branches of 0.3% and 0.07% in 31Cl and 27P, respectively, were estimated. Several proton peaks that had been previously assigned to the decay of 31Cl were shown to be from the decay of 25Si. In 27P, two proton groups at 459 ± 14 keV and 610 ± 11 keV, with intensities of 7 ± 3% and 92 ± 4% relative to the main (100%) group were discovered. The Gamow-Teller component of the preceding beta-decay of each observed proton transition was compared to results from shell model calculations. Finally, a new proton transition was identified, following the β-decay of 28P, at 1,444 ± 12 keV with a 1.7 ± 0.5% relative intensity to the 100% group. Using similar low-energy detector telescopes and the mass separator TISOL at TRIUMF, the 109 msec and 173 msec activities, 17Ne and 33Ar, were studied. A new proton group with energy 729 ± 15 keV was observed following the beta-decay of 17Ne. Several discrepancies between earlier works as to the energies, intensities and assignments of several proton transitions from 17Ne and 33Ar were resolved

  11. Competition of $\\beta$-delayed protons and $\\beta$-delayed $\\gamma$ rays in $^{56}$Zn and the exotic $\\beta$-delayed $\\gamma$-proton decay

    CERN Document Server

    Orrigo, S E A; Fujita, Y; Blank, B; Gelletly, W; Agramunt, J; Algora, A; Ascher, P; Bilgier, B; Cáceres, L; Cakirli, R B; Fujita, H; Ganioglu, E; Gerbaux, M; Giovinazzo, J; Grévy, S; Kamalou, O; Kozer, H C; Kucuk, L; Kurtukian-Nieto, T; Molina, F; Popescu, L; Rogers, A M; Susoy, G; Stodel, C; Suzuki, T; Tamii, A; Thomas, J C

    2016-01-01

    Remarkable results have been published recently on the $\\beta$ decay of $^{56}$Zn. In particular, the rare and exotic $\\beta$-delayed $\\gamma$-proton emission has been detected for the first time in the $fp$ shell. Here we focus the discussion on this exotic decay mode and on the observed competition between $\\beta$-delayed protons and $\\beta$-delayed $\\gamma$ rays from the Isobaric Analogue State.

  12. Beta-delayed proton emission from 21Mg

    International Nuclear Information System (INIS)

    Beta-delayed proton emission from 21Mg has been measured at ISOLDE, CERN, with a detection setup consisting of two charged-particle telescopes surrounding the decay point. Altogether 27 βp branches were measured with center-of-mass energies between 0.4-7.2 MeV. Seven new βp branches were observed. Beta-delayed protons were used to determine the half-life of 21Mg as 118.6 ± 0.5 ms. From a line shape fit of the βp branches we extract the widths, spins, and parities of the resonances of 21Na. An improved interpretation of the decay scheme in accordance with the results obtained in reaction studies is presented. (orig.)

  13. Beta-delayed proton emission from {sup 21}Mg

    Energy Technology Data Exchange (ETDEWEB)

    Lund, M.V.; Fynbo, H.O.U.; Jensen, J.H.; Laursen, K.L.; Riisager, K. [Aarhus University, Department of Physics and Astronomy, Aarhus C (Denmark); Borge, M.J.G. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); CERN, ISOLDE, PH Department, Geneva 23 (Switzerland); Briz, J.A.; Perea, A.; Pesudo, V.; Tengblad, O. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); Cederkaell, J. [Lund University, Department of Nuclear Physics, Lund (Sweden); Jonson, B.; Nilsson, T. [Chalmers University of Technology, Department of Fundamental Physics, Goeteborg (Sweden)

    2015-09-15

    Beta-delayed proton emission from {sup 21}Mg has been measured at ISOLDE, CERN, with a detection setup consisting of two charged-particle telescopes surrounding the decay point. Altogether 27 βp branches were measured with center-of-mass energies between 0.4-7.2 MeV. Seven new βp branches were observed. Beta-delayed protons were used to determine the half-life of {sup 21}Mg as 118.6 ± 0.5 ms. From a line shape fit of the βp branches we extract the widths, spins, and parities of the resonances of {sup 21}Na. An improved interpretation of the decay scheme in accordance with the results obtained in reaction studies is presented. (orig.)

  14. Beta delayed alpha emission from the neutron deficient rare earth isotopes 152Tm and 150Ho

    International Nuclear Information System (INIS)

    The study of beta-delayed proton emission is a well known method to aid the determination of the beta strength distribution in nuclei far from the stability line. At the neutron deficient side of the nuclear chart the process of proton or alpha emission from excited states is energetically allowed when one goes far enough from stability. However, beta-delayed alphas have seldom been measured for nuclei heavier than A = 20. Here we present a study of the beta-delayed alpha-particle emission from 152Tm and 150Ho and their importance in the full B(GT) distribution.

  15. Neutron-gamma competition for $\\beta$-delayed neutron emission

    CERN Document Server

    Mumpower, Matthew; Moller, Peter

    2016-01-01

    We present a coupled Quasi-particle Random Phase Approximation and Hauser-Feshbach (QRPA+HF) model for calculating delayed particle emission. This approach uses microscopic nuclear structure information which starts with Gamow-Teller strength distributions in the daughter nucleus, and then follows the statistical decay until the initial available excitation energy is exhausted. Explicitly included at each particle emission stage is $\\gamma$-ray competition. We explore this model in the context of neutron emission of neutron-rich nuclei and find that neutron-gamma competition can lead to both increases and decreases in neutron emission probabilities, depending on the system considered. A second consequence of this formalism is a prediction of more neutrons on average being emitted after $\\beta$-decay for nuclei near the neutron dripline compared to models that do not consider the statistical decay.

  16. Beta-Delayed Neutron Spectroscopy Using VANDLE at CARIBU

    Science.gov (United States)

    Taylor, S.; Kolos, K.; Grzywacz, R.; Paulauskas, S. V.; Madurga, M.; Savard, G.; Brewer, N. T.; Vandle Collaboration

    2015-10-01

    Measurement of spectroscopic information on beta-delayed neutrons of neutron rich fission fragments is of interest to the areas of astrophysics, reactor design, nuclear structure and stockpile stewardship. Using the Time of Flight (TOF) method, the Versatile Array of Neutron Detectors at Low Energy(VANDLE)[1,2,3] measured fission fragments of 252Cf provided by CARIBU at Argonne National Lab. 135,136Sb and 85As isotopes were measured to explore the nuclear structure around doubly magic nuclei 132Sn and 78Ni. A new TOF start detector was developed for this experiment using new Silicon Photo-Multipliers from SensL to allow for a lower beta particle energy detection threshold and better timing resolution compared to previous VANDLE experiments. This work is funded by the U.S. Department of Energy NNSA under the Stewardship Science Academic Alliance program through DOE Cooperative Agreement No. DE-FG52-08NA28552.

  17. Study of the Beta-delayed multiple particle break-up of the 2.43 MeV state in Be-9

    Science.gov (United States)

    Madurga Flores, Miguel; Borge, M. J. G.; Fynbo, H. O. U.; Jonson, B.; Nyman, G.; Prezado, Y.; Riisager, K.

    The aim of this work is to study the β -delayed multiparticle break-up of the 5/2- state in 9 Be at 2.43 MeV excitation energy. This process is relevant as it has been proposed recently that this level plays a role in the α(αn,γ)9 Be reaction. This state breaks-up in 2α+n, and sequential as well as direct ("democratic") decay have previously been considered. In our work energy and direction of the two emitted α particles has been measured, while those of the neutron have been reconstructed. The sequential decay is considered using the R-matrix formalism. For the democratic decay the hyper-spherical harmonics functions are used. The different decay processes are compared with the data using the Monte-Carlo method. Our preliminary results indicate that the data is better described when democratic decay is assumed.

  18. Fabrication of beta particles detector for RMS

    International Nuclear Information System (INIS)

    The beta particles detector for RMS (radiation monitoring system) was fabricated to detect charged beta particles. The plastic scintillator was cutted, shaped, polished to make plastic disk for beta particles. The diameter of completed plastic scintillator disk is 40 mm and thickness is 1.5 mm. The mylar film and aluminium foil were used the front of plastic scintillator to intercept light and moisture. The completed plastic detector for RMS consist of the discriminator and counter were made by ULS (Co.). The absolute efficiency of plastic detector was 45.51% for beta particles (Sr/Y - 90)

  19. Lauch of CERN particle accelerator delayed

    CERN Multimedia

    2007-01-01

    "Scientists seeking to uncover the secrets of the universe will have to wait a little longer after the CERN laboratory inSwitzerland yesterday confirmed a delay in tests of its massive new particle accelerator." (1 page)

  20. Beta-delayed fission probabilities of transfermium nuclei, involved in the r-process

    Science.gov (United States)

    Panov, I.; Lutostansky, Yu; Thielemann, F.-K.

    2016-01-01

    For the nucleosynthesis of heavy and superheavy nuclei fission becomes very important when the r-process runs in a very high neutron density environment. In part, fission is responsible for the formation of heavy nuclei due to the inclusion of fission products as new seed nuclei (fission cycling). More than that, beta-delayed fission, along with spontaneous fission, is responsible in the late stages of the r-process for the suppression of superheavy element yields. For beta-delayed fission probability calculations a model description of the beta-strength- functions is required. Extended theoretical predictions for astro-physical applications were provided long ago, and new predictions also for superheavy nuclei with uptodate nuclear input are needed. For the further extension of data to heavier transactinides the models of strength- functions should be modified, taking into account more complicated level schemes. In our present calculations the strength-function model is based on the quasi-particle approximation of Finite Fermi Systems Theory. The probabilities of beta-delayed fission and beta-delayed neutron emission are calculated for some transfermium neutron-rich nuclei, and the influence of beta-delayed fission upon superheavy element formation is discussed.

  1. On the time delay between ultrarelativistic particles

    CERN Document Server

    Fleury, Pierre

    2016-01-01

    The time delay between the receptions of ultrarelativistic particles emitted simultaneously is an observable for both fundamental physics and cosmology. The expression of the delay when the particles travel through an arbitrary spacetime has been derived recently in arXiv:1512.08489, using a particular coordinate system and self-consistent assumptions. In this article I show that this formula enjoys a simple physical interpretation: the relative velocity between two ultrarelativistic particles is constant. This result reveals an interesting kinematical property of general relativity, namely that the tidal forces experienced by ultrarelativistic particles in the direction of their motion are much smaller than those experienced orthogonally to their motion.

  2. Beta-delayed neutron decay of $^{33}$Na

    CERN Document Server

    Radivojevic, Z; Caurier, E; Cederkäll, J; Courtin, S; Dessagne, P; Jokinen, A; Knipper, A; Le Scornet, G; Lyapin, V G; Miehé, C; Nowacki, F; Nummela, S; Oinonen, M; Poirier, E; Ramdhane, M; Trzaska, W H; Walter, G; Äystö, J

    2002-01-01

    Beta-delayed neutron decay of /sup 33/Na has been studied using the on-line mass separator ISOLDE. The delayed neutron spectra were measured by time-of-flight technique using fast scintillators. Two main neutron groups at 800(60) and 1020(80) keV were assigned to the /sup 33/Na decay, showing evidence for strong feeding of states at about 4 MeV in /sup 33/Mg. By simultaneous beta - gamma -n counting the delayed neutron emission probabilities P/sub 1n/ = 47(6)% and P /sub 2n/ = 13(3)% were determined. The half-life value for /sup 33 /Na, T/sub 1/2/ = 8.0(3) ms, was measured by three different techniques, one employing identifying gamma transitions and two employing beta and neutron counting. (21 refs).

  3. Delay Equation for Charged Brown Particle

    OpenAIRE

    Vlasov, Alexander A.

    2001-01-01

    In previous work (physics/0004026) was shown, with the help of numerical calculations, that the effective Brown temperature for charged particle is lower than that for particle without charge. Here we derive this result without numerical calculations, integrating the delay equation analytically, as for zero, so for nonzero viscosity.

  4. Beta particle monitor for surfaces

    International Nuclear Information System (INIS)

    A beta radiation detector which is capable of reliably detecting beta radiation emitted from a surface. An electrically conductive signal collector is adjustably mounted inside an electrically conductive enclosure which may define a single large opening for placing against a surface. The adjustable mounting of the electrically conductive signal collector can be based on the distance from the surface or on the expected beta energy range. A voltage source is connected to the signal collector through an electrometer or other display means for creating an electric field between the signal collector and the enclosure. Air ions created by the beta radiation are collected and the current produced is indicated on the electrometer or other display means. 2 figs

  5. Characterization of a neutron–beta counting system with beta-delayed neutron emitters

    OpenAIRE

    Agramunt, J.; Tain, J.L.; Gómez-Hornillos, M. B.; GARCIA A. R.; Albiol, F; Algora, A.; Caballero-Folch, R.; CALVIÑO F.; Cano-Ott, D.; Cortés, G.; Domingo-Pardo, C.; Eronen, Tommi; Gelletly, W.; Gorelov, Dmitry; Gorlychev, V.

    2016-01-01

    A new detection system for the measurement of beta-delayed neutron emission probabilities has been characterized using fission products with well known β-delayed neutron emission properties. The setup consists of BELEN-20, a 4π neutron counter with twenty 3He proportional tubes arranged inside a large polyethylene neutron moderator, a thin Si detector for β counting and a selftriggering digital data acquisition system. The use of delayed-neutron precursors with different neutron emis...

  6. Characterization of a neutron-beta counting system with beta-delayed neutron emitters

    OpenAIRE

    Agramunt Ros, Jorge; Taín, J. L.; Gómez Hornillos, María Belén; Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere; Pretel Sánchez, Carme; Riego Pérez, Albert; Tarifeño Saldivia, Ariel Esteban

    2016-01-01

    A new detection system for the measurement of beta-delayed neutron emission probabilities has been characterized using fission products with well known ß-delayed neutron emission properties. The setup consists of BELEN-20, a 4p neutron counter with twenty 3He proportional tubes arranged inside a large polyethylene neutron moderator, a thin Si detector for ß counting and a self-triggering digital data acquisition system. The use of delayed-neutron precursors with different neutron emission win...

  7. Delayed Particle Study of Neutron Rich Lithium Isotopes

    CERN Multimedia

    Marechal, F; Perrot, F

    2002-01-01

    We propose to make a systematic complete coincidence study of $\\beta$-delayed particles from the decay of neutron-rich lithium isotopes. The lithium isotopes with A=9,10,11 have proven to contain a vast information on nuclear structure and especially on the formation of halo nuclei. A mapping of the $\\beta$-strength at high energies in the daughter nucleus will make possible a detailed test of our understanding of their structure. An essential step is the comparison of $\\beta$-strength patterns in $^{11}$Li and the core nucleus $^{9}$Li, another is the full characterization of the break-up processes following the $\\beta$-decay. To enable such a measurement of the full decay process we will use a highly segmented detection system where energy and emission angles of both charged and neutral particles are detected in coincidence and with high efficiency and accuracy. We ask for a total of 30 shifts (21 shifts for $^{11}$Li, 9 shifts $^{9}$Li adding 5 shifts for setting up with stable beam) using a Ta-foil target...

  8. Beta-delayed neutron spectroscopy using trapped radioactive ions

    OpenAIRE

    Yee, Ryan Matthew

    2013-01-01

    A novel technique for beta-delayed neutron spectroscopy has been developed using trapped radioactive ions. The neutron energy spectrum was reconstructed by measuring the time of flight (TOF) of the nuclear recoil following neutron emission, thereby avoiding all the challenges associated with neutron detection such as backgrounds from scattered neutrons and gamma rays and complicated detector-response functions. A proof-of-principle measurement was conducted on 137I+ by delivering ions from a ...

  9. Search for $\\beta$-delayed protons from $^{11}$Be

    CERN Multimedia

    $\\beta$-delayed proton emission from $^{11}$Be will be a very rare process. It is believed to decay directly into continuum states. This would imply that it will be a sensitive probe of the halo structure of the one-neutron halo nucleus $^{11}$Be. We propose to improve existing (unpublished) limits on this decay mode by two orders of magnitude. Our earlier experience at ISOLDE indicates that the required intensity and purity of the source can be obtained. The branching ratio will be measured by counting the number of $^{10}$Be atoms produced via accelerator mass spectrometry.

  10. MONSTER: a TOF Spectrometer for beta-delayed Neutron Spetroscopy

    CERN Document Server

    Martinez, T; Castilla, J; Garcia, A R; Marin, J; Martinez, G; Mendoza, E; Santos, C; Tera, F; Jordan, M D; Rubio, B; Tain, J L; Bhattacharya, C; Banerjee, K; Bhattacharya, S; Roy, P; Meena, J K; Kundu, S; Mukherjee, G; Ghosh, T K; Rana, T K; Pandey, R; Saxena, A; Behera, B; Penttila, H; Jokinen, A; Rinta-Antila, S; Guerrero, C; Ovejero, M C; Villamarin, D; Agramunt, J; Algora, A

    2014-01-01

    Beta-delayed neutron (DN) data, including emission probabilities, P-n, and energy spectrum, play an important role in our understanding of nuclear structure, nuclear astrophysics and nuclear technologies. A MOdular Neutron time-of-flight SpectromeTER (MONSTER) is being built for the measurement of the neutron energy spectra and branching ratios. The TOF spectrometer will consist of one hundred liquid scintillator cells covering a significant solid angle. The MONSTER design has been optimized by using Monte Carlo (MC) techniques. The response function of the MONSTER cell has been characterized with mono-energetic neutron beams and compared to dedicated MC simulations.

  11. Beta-decay rate and beta-delayed neutron emission probability of improved gross theory

    Science.gov (United States)

    Koura, Hiroyuki

    2014-09-01

    A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for unmeasured nuclei are adopted from the KTUY nuclear mass formula, which is based on the spherical-basis method. Considering the properties of the integrated Fermi function, we can roughly categorized energy region of excited-state of a daughter nucleus into three regions: a highly-excited energy region, which fully affect a delayed neutron probability, a middle energy region, which is estimated to contribute the decay heat, and a region neighboring the ground-state, which determines the beta-decay rate. Some results will be given in the presentation. A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for

  12. The statistical properties of the angular distribution of beta delayed protons from oriented nuclei

    CERN Document Server

    Stone, N J; Wöhr, A

    2000-01-01

    Statistical model of beta -delayed proton emission is briefly reviewed. Theory of angular distribution of beta -delayed proton emission from nuclear states oriented at low temperatures is discussed and the design of the first trial experiment using /sup 118 /Cs oriented at low temperature at the ISOLDE/NICOLE facility at CERN is described. (14 refs).

  13. Problems at the Development of personal Beta-particle dosemeters-Beta Particle dosemeters-

    International Nuclear Information System (INIS)

    Workplaces at which beta radiation might significantly contribute to the doses to the extremities are increasingly found in radiation therapy, radiation source production and nuclear plants. for the measurement of the individual beta-particle dose, personal dosemeters for fingers, arms and legs are needed. Intercomparison measurements organised from 1996 by the PTB have shown that some dosemeter types based on TLD are suitable for this purpose and can be used as legal dosemeters for both photon and beta radiation. Also, some electronic personal photon dosemeters are investigated in beta radiation fields. it turned out that a few types are also sensitive to beta radiation and measure the personal dose equivalent rate to the skin with a low energy dependence. Only their wearing position is by far not optimal foe extremity dosimetry because they are worn on the chest. Advantages and disadvantages are discussed. The characterisation of workplaces is carried out by measuring dose profiles using area dosemeters. Investigations performed with several commercial types of these dosemeters furnish information about the selection of the suitable measuring device and its correct practical use. the development of improved dosemeters has to towards smaller detectors and higher sensitivity. Personal dosemeters have to be robust and acceptable to the user, which generally is not achieved for beta extremity dosemeters. It is an additional problem that even such dosemeters cannot always be worn in the appropriate place. (Author)

  14. Scientists confirm delay in testing new CERN particle accelerator

    CERN Multimedia

    2007-01-01

    "Scientists seeking to uncover the secrets of the universe will have to wait a little longer after the CERN laboratory inswitzerland on Monday confirmed a delay in tests of a massive new particle accelerator." (1 page)

  15. New particle searches by double beta decay

    International Nuclear Information System (INIS)

    So far, neutrinoless double beta decay has not been observed, but the lifetime limit (3-10/sup 23/ years) is such a stringent one that its non-observation can set the best upper limit for the mass of the electron neutrino (if it is a Majorana particle) and the best lower limit on the mass of a heavy Majorana neutrino for a given coupling to the electron neutrino, ν/sub e/. In addition it provides the best limit on the coupling of light bosons, such as Majorons, to ν/sub e/, and also the best limit on the existence of right-handed currents in the case in which all right-handed Majorana neutrinos are heavier than all left-handed leptons. The apparatus has to have such low backgrounds even in the keV energy region that it also can be used to set the best terrestrial limits on the mass of solar axions and of other dark matter candidates

  16. $\\beta$-delayed neutron spectroscopy of $^{130-132}$ Cd isotopes with the ISOLDE decay station and the VANDLE array

    CERN Multimedia

    We propose to use the new ISOLDE decay station and the neutron detector VANDLE to measure the $\\beta$-delayed neutron emission of N=82-84 $^{130-132}$Cd isotopes. The large delayed neutron emission probability observed in a previous ISOLDE measurement [M. Hannawald et al., Phys. Rev. C62, 054301 (2000)] is indicative of the Gamow-Teller transitions due to the decay of deep core neutrons. Core Gamow-Teller decay has been experimentally proven in the $^{78}$Ni region for the N>50 nuclei using the VANDLE array. The spectrocopic measurement of delayed neutron emission along the cadmium isotopic chain will allow us to track the evolution of the single particle states and the shell gap.

  17. Beta particle dose rates to micro-organisms in soil

    International Nuclear Information System (INIS)

    Studies were made to estimate the beta-particle dose rates to micro-organisms of various sizes in soil. The small insects and organisms living in soil are constantly exposed to beta-radiation arising from naturally occuring radionuclides in soil as in this case no overlying tissue shields them. The technique of measuring beta-particle dose rate consisted of using of a thin plastic scintillator to measure the pulse height distribution as the beta particle traverses the scintillator. The integrated response was determined by the number and size of the photomultiplier pulses. From the data of soil analyses it was estimated that typically about 29% of the beta particles emitted per gm. of soil were contributed by the U/Ra series, 21% by the Th series and about 50% by potassium. By combining the individual spectra of these three radionuclides in the proportion found in a typical soil, a resultant spectrum was computed representing the energy distribution of the beta particles. The dose rate received by micro-organisms of different shape and size in soil was derived from the equilibrium dose rates combined with a 'Geometrical Factor' of the organisms. For small organisms, the dose rates did not vary between the spherical and cylindrical types, but in the case of larger organisms, the dose rates were found to be greater for the spherical types of the same diameter. (auth.)

  18. The Mechanism of $\\beta$-Delayed Two-Proton Emission

    CERN Multimedia

    2002-01-01

    The nucleus $^{31}$Ar seems to be the most prolific ${\\beta}$-2p precursor known to date and is at the same time the one with the largest production yields at ISOLDE, where the most sensitive experiments can be done. Our purpose with this experiment is to study the ${\\beta}$-2p branches in detail, search for ${\\beta}$-3p events, place them in the decay scheme and obtain information on the decay mechanism for ${\\beta}$-2p via the energy distribution and the angular correlation between the two protons. As a by product we shall also resolve existing inconsistencies in the level scheme.\\\\ \\\\ The nucleus $^{31}$Ar, produced in a cold plasma ion source unit by the impact of a 1 GeV proton beam of 0.5 Hz frequency, had an average yield over one week of 1.5 $^{31}$Ar atoms/s. The beam passed through the central hole of an annular Si detector ($\\Omega$ = 4.3~\\%) and stopped in a thin carbon foil tilted 45$^o$ with respect to the beam direction. A 70~\\% coaxial HPGe-detector ($\\Omega$~=~7.4~\\%) was located opposite to ...

  19. Beta-delayed gamma decay of 26P: Possible evidence of a proton halo

    CERN Document Server

    Pérez-Loureiro, D; Bennett, M B; Liddick, S N; Bowe, A; Brown, B A; Chen, A A; Chipps, K A; Cooper, N; Irvine, D; McNeice, E; Montes, F; Naqvi, F; Ortez, R; Pain, S D; Pereira, J; Prokop, C J; Quaglia, J; Quinn, S J; Sakstrup, J; Santia, M; Schwartz, S B; Shanab, S; Simon, A; Spyrou, A; Thiagalingam, E

    2016-01-01

    Background: Measurements of $\\beta$ decay provide important nuclear structure information that can be used to probe isospin asymmetries and inform nuclear astrophysics studies. Purpose: To measure the $\\beta$-delayed $\\gamma$ decay of $^{26}$P and compare the results with previous experimental results and shell-model calculations. Method: A $^{26}$P fast beam produced using nuclear fragmentation was implanted into a planar germanium detector. Its $\\beta$-delayed $\\gamma$-ray emission was measured with an array of 16 high-purity germanium detectors. Positrons emitted in the decay were detected in coincidence to reduce the background. Results: The absolute intensities of $^{26}$P $\\beta$-delayed $\\gamma$-rays were determined. A total of six new $\\beta$-decay branches and 15 new $\\gamma$-ray lines have been observed for the first time in $^{26}$P $\\beta$-decay. A complete $\\beta$-decay scheme was built for the allowed transitions to bound excited states of $^{26}$Si. $ft$ values and Gamow-Teller strengths were a...

  20. Delayed-particle spectroscopy on very exotic nuclei at Ganil

    International Nuclear Information System (INIS)

    This paper describes recent developments concerning the spectroscopy of the preponderate decay mode of these nuclei far off stability: their high β decay energy 0β opens up the window for decay into particle-unstable states of the daughter nucleus leading to β delayed proton or neutron emission in the case of very neutron-deficient or neutron-rich nuclei, respectively

  1. Search for {beta}-delayed fission of the heavy neutron-rich isotope {sup 230}Ac

    Energy Technology Data Exchange (ETDEWEB)

    Shuanggui Yuan; Weifan Yang; Yanbing Xu; Qiangyan Pan; Bing Xiong; Jianjun He; Dong Wang; Yingjun Li; Taotao Ma; Zhenguo Yang [Academia Sinica, Lanzhou, GS (China). Inst. of Modern Physics

    2001-01-01

    The {sup 230}Ra has been produced via multinucleon transfer reaction and dissipative fragmentation by 60 MeV/u {sup 18}O ion irradiation of {sup 232}Th targets. The radium was radiochemically separated from the mixture of thorium and reaction products. Thin Ra sources were prepared and exposed to the mica fission track detectors, and measured by a HPGe gamma detector. It is likely that the {beta}-delayed fission of {sup 230}Ac was observed for the first time and the {beta}-delayed fission probability of {sup 230}Ac was tentatively found to be (1.19{+-}0.40) x 10{sup -8}. (orig.)

  2. Observation of Doppler broadening in $\\beta$-delayed proton-$\\gamma$ decay

    CERN Document Server

    Schwartz, S B; Bennett, M B; Liddick, S N; Perez-Loureiro, D; Bowe, A; Chen, A A; Chipps, K A; Cooper, N; Irvine, D; McNeice, E; Montes, F; Naqvi, F; Ortez, R; Pain, S D; Pereira, J; Prokop, C; Quaglia, J; Quinn, S J; Sakstrup, J; Santia, M; Shanab, S; Simon, A; Spyrou, A; Thiagalingam, E

    2015-01-01

    Background: The Doppler broadening of $\\gamma$-ray peaks due to nuclear recoil from $\\beta$-delayed nucleon emission can be used to measure the energies of the nucleons. This method has never been tested using $\\beta$-delayed proton emission or applied to a recoil heavier than $A=10$. Purpose: To test and apply this Doppler broadening method using $\\gamma$-ray peaks from the $^{26}$P($\\beta p\\gamma$)$^{25}$Al decay sequence. Methods: A fast beam of $^{26}$P was implanted into a planar Ge detector, which was used as a $^{26}$P $\\beta$-decay trigger. The SeGA array of high-purity Ge detectors was used to detect $\\gamma$ rays from the $^{26}$P($\\beta p\\gamma$)$^{25}$Al decay sequence. Results: Radiative Doppler broadening in $\\beta$-delayed proton-$\\gamma$ decay was observed for the first time. The Doppler broadening analysis method was verified using the 1613 keV $\\gamma$-ray line for which the proton energies were previously known. The 1776 keV $\\gamma$ ray de-exciting the 2720 keV $^{25}$Al level was observed...

  3. High-resolution studies of beta-delayed proton emitters at IGISOL facility

    NARCIS (Netherlands)

    Jokinen, A; Aysto, J; Dendooven, P; Hankonen, S; Honkanen, A; Huikari, J; Lhersonneau, G; Lipas, PO; Penttila, H; Perajarvi, K; Oinonen, M; Nieminen, A; Siiskonen, T; Wang, JC

    1998-01-01

    Beta-decays of Al-23 and Ti-41 have been studied by applying ion guide techniques, gamma detection and a gas-Si telescope for charged-particle detection. The experimental beta-decay strength of Ti-41 was found to be quenched by a factor of q(2) = 0.64 compared to our shell model calculations below 8

  4. First measurement of several $\\beta$-delayed neutron emitting isotopes beyond N=126

    CERN Document Server

    Caballero-Folch, R; Agramunt, J; Algora, A; Ameil, F; Arcones, A; Ayyad, Y; Benlliure, J; Borzov, I N; Bowry, M; Calvino, F; Cano-Ott, D; Cortés, G; Davinson, T; Dillmann, I; Estrade, A; Evdokimov, A; Faestermann, T; Farinon, F; Galaviz, D; García, A R; Geissel, H; Gelletly, W; Gernhäuser, R; Gómez-Hornillos, M B; Guerrero, C; Heil, M; Hinke, C; Knöbel, R; Kojouharov, I; Kurcewicz, J; Kurz, N; Litvinov, Y; Maier, L; Marganiec, J; Marketin, T; Marta, M; Martínez, T; Martínez-Pinedo, G; Montes, F; Mukha, I; Napoli, D R; Nociforo, C; Paradela, C; Pietri, S; Podolyák, Zs; Prochazka, A; Rice, S; Riego, A; Rubio, B; Schaffner, H; Scheidenberger, Ch; Smith, K; Sokol, E; Steiger, K; Sun, B; Taín, J L; Takechi, M; Testov, D; Weick, H; Wilson, E; Winfield, J S; Wood, R; Woods, P; Yeremin, A

    2015-01-01

    The $\\beta$-delayed neutron emission probabilities of neutron rich Hg and Tl nuclei have been measured together with $\\beta$-decay half-lives for 20 isotopes of Au, Hg, Tl, Pb and Bi in the mass region N$\\gtrsim$126. These are the heaviest species where neutron emission has been observed so far. These measurements provide key information to evaluate the performance of nuclear microscopic and phenomenological models in reproducing the high-energy part of the $\\beta$-decay strength distribution. In doing so, it provides important constraints to global theoretical models currently used in $r$-process nucleosynthesis.

  5. Development of an effective delayed neutron fraction calculation code, BETA-K

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taek Kyum; Song, Hoon; Kim, Young Il; Kim, Young In; Kim, Young Jin [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-08-01

    BETA-K, an effective delayed neutron fraction calculation code consistent with Nodal Expansion Method (NEM), has been developed. By using relevant output files of DIF3D code, it can calculate the effective delayed neutron fraction({beta}{sub eff}), neutron lifetime(l{sub eff}), fission spectrum ({chi}-bar) and fission yield data({nu}) for each fissionable isotope, composition of fuels and over the whole core. BETA-K code has been validated by comparing the calculated values to the measured ones of effective delayed neutron fraction in two critical experiments, BFS73-1 and BFS55-1. BFS73-1 is a metal uranium core and BFS55-1 is a metal plutonium core. The C/E values, 1.007 and 0.992 for BFS73-1 and BFS55-1 respectively, agreed well with the experimental values within the experiment errors. BETA-K code predicts 0.00709 and 0.356 {mu}sec as the effective delayed neutron fraction and neutron life time for the uranium metallic fueled equilibrium core of 150MWe KALIMER. (author). 9 refs., 6 figs., 12 tabs.

  6. Delay in solar energetic particle onsets at high heliographic latitudes

    Directory of Open Access Journals (Sweden)

    S. Dalla

    Full Text Available Ulysses observations have shown that solar energetic particles (SEPs can easily reach high heliographic latitudes. To obtain information on the release and propagation of SEPs prior to their arrival at Ulysses, we analyse the onsets of nine large high-latitude particle events. We measure the onset times in several energy channels, and plot them versus inverse particle speed. This allows us to derive an experimental path length and time of release from the solar atmosphere. We repeat the procedure for near-Earth observations by Wind and SOHO. We find that the derived path lengths at Ulysses are 1.06 to 2.45 times the length of a Parker spiral magnetic field line connecting the spacecraft to the Sun. The time of particle release from the Sun is between 100 and 350 min later than the release time derived from in-ecliptic measurements. We find no evidence of correlation between the delay in release and the inverse of the speed of the CME associated with the event, or the inverse of the speed of the corresponding interplanetary shock. The main parameter determining the magnitude of the delay appears to be the difference in latitude between the flare and the footpoint of the spacecraft.

    Key words. Interplanetary physics (energetic particles – Solar physics, astrophysics and astronomy (energetic particles, flares and mass ejections

  7. {beta}-delayed neutron emission measurements around the third r-process abundance peak

    Energy Technology Data Exchange (ETDEWEB)

    Caballero-Folch, R.; Cortes, G.; Calvino, F.; Gomez-Hornillos, M. B.; Riego, A. [INTE-DFEN, Universitat Politecnica de Catalunya, Barcelona (Spain); Domingo-Pardo, C.; Tain, J. L.; Agramunt, J.; Rubio, B. [IFIC, CSIC-University of Valencia, Valencia (Spain); Algora, A. [IFIC, CSIC-University of Valencia, Valencia (Spain) and Inst. Nucl. Research, Debrecen (Hungary); Ameil, F.; Farinon, F.; Heil, M.; Knoebel, R.; Kojouharov, I.; Kurcewicz, J.; Kurz, N.; Litvinov, Y.; Mukha, I.; Nociforo, C. [GSI, Darmstadt (Germany); and others

    2013-06-10

    This contribution summarizes an experiment performed at GSI (Germany) in the neutron-rich region beyond N=126. The aim of this measurement is to provide the nuclear physics input of relevance for r-process model calculations, aiming at a better understanding of the third r-process abundance peak. Many exotic nuclei were measured around {sup 211}Hg and {sup 215}Tl. Final ion identification diagrams are given in this contribution. For most of them, we expect to derive halflives and and {beta}-delayed neutron emission probabilities. The detectors used in this experiment were the Silicon IMplantation and Beta Absorber (SIMBA) detector, based on an array of highly segmented silicon detectors, and the BEta deLayEd Neutron (BELEN) detector, which consisted of 30 3He counters embedded in a polyethylene matrix.

  8. Search for beta-delayed protons from 11Be

    International Nuclear Information System (INIS)

    The one-neutron halo nucleus 11Be can emit a proton in a beta decay of the halo neutron. However, due to the Q-value of this decay channel (280.7±0.3 keV) the expected branching ratio will be very low - most estimates are a few times 10-8 - and the detection of the outgoing proton with a kinetic energy of a few hundred keV is challenging. Therefore our attempt was to detect the remaining nucleus 10Be with the help of accelerator mass spectrometry (AMS). AMS is a highly sensitive tool to detect radioisotopes at the ultra-trace level. A beam of 11Be ions was produced at the ISOLDE facility at CERN and implanted in a collection sample. The sample was transferred to the VERA AMS facility at the University of Vienna where the 10Be content was determined. In my talk I present details of the experiment and results of the successful detection of this rare decay channel.

  9. Measurement of the branching ratio for beta-delayed alpha decay of 16N

    CERN Document Server

    Refsgaard, J; Dijck, E A; Fynbo, H O U; Lund, M V; Portela, M N; Raabe, R; Randisi, G; Renzi, F; Sambi, S; Sytema, A; Willmann, L; Wilschut, H W

    2015-01-01

    While the 12C(a,g)16O reaction plays a central role in nuclear astrophysics, the cross section at energies relevant to hydrostatic helium burning is too small to be directly measured in the laboratory. The beta-delayed alpha spectrum of 16N can be used to constrain the extrapolation of the E1 component of the S-factor; however, with this approach the resulting S-factor becomes strongly correlated with the assumed beta-alpha branching ratio. We have remeasured the beta-alpha branching ratio by implanting 16N ions in a segmented Si detector and counting the number of beta-alpha decays relative to the number of implantations. Our result, 1.49(5)e-5, represents a 25% increase compared to the accepted value and implies an increase of 14% in the extrapolated S-factor.

  10. New Therapeutic Approaches to Prevent or Delay Beta-Cell Failure in Diabetes

    Directory of Open Access Journals (Sweden)

    Ionica Floriana Elvira

    2015-09-01

    Full Text Available Background and aims: The most recent estimates of International Diabetes Federation indicate that 382 million people have diabetes, and the incidence of this disease is increasing. While in type 1 diabetes mellitus (T1DM beta-cell death is autoimmunemediated, type 2 diabetes mellitus (T2DM results from an interaction between genetic and environmental factors that impair beta-cell function and insulin action. Many people with T2DM remain unaware of their illness for a long time because symptoms may take years to appear or be recognized, while the body is affected by excess blood glucose. These patients are often diagnosed only when diabetes complications have already developed. The aim of this article was to perform a review based on literature data on therapeutic modalities to prevent/delay beta cell function decline. Material and Methods: We searched MEDLINE from 2000 to the present to identify the therapeutic approaches to prevent or delay beta-cell failure in patients with T2DM. Results and conclusions: Several common polymorphisms in genes linked to monogenic forms of diabetes appear to influence the response to T2DM pharmacotherapy. Recent studies report the role of the G protein coupled receptor 40 (GPR40, also known as Free Fatty Acids Receptor 1 (FFAR1 in the regulation of beta-cell function- CNX-011-67 (a GPR40 agonist has the potential to provide good and durable glycemic control in T2DM patients.

  11. Lactose crystallization delay in model infant foods made with lactose, beta-lactoglobulin, and starch.

    Science.gov (United States)

    Nasirpour, A; Landillon, V; Cuq, B; Scher, J; Banon, S; Desobry, S

    2007-08-01

    Handling and storage alter infant food powders due to lactose crystallization and interactions among components. Model infant foods were prepared by colyophilization of lactose, beta-lactoglobulin (beta-LG), and gelatinized starch. A mixture design was used to define the percentage of each mixture component to simulate a wide range of infant food powders. The kinetics of crystallization was studied by a gravimetric method (dynamic vapor sorption) at 70% relative humidity (RH). After freeze-drying, lactose was amorphous and crystallized at 70% RH. The delay before crystallization depends on the contents of beta-LG and starch in the formulations. A mathematical model was proposed to predict crystallization time (delay) at 70% RH. For the formulation containing 50% lactose, 25% beta-LG, and 25% starch, lactose was still amorphous after 42 h at 70% RH, whereas pure amorphous lactose crystallized after approximately 70 min. Calculated and experimental results of adsorbed moisture from the formulations were compared. Adsorbed water of formulation containing lactose could not be calculated from moisture sorption properties of each component at a given RH because beta-LG and gelatinized starch prevented lactose crystal growth. PMID:17638972

  12. Phoswich Detector for Simultaneous Measuring Alpha/beta Particles

    International Nuclear Information System (INIS)

    The new type phoswich detector consisting of the ZnS(Ag) and plastic scintillator for alpha/beta-ray simultaneous counting was developed for monitoring radiological contamination inside pipes. The detection performance was estimated using the PSD (pulse shape discrimination) method as a function of distance between the scintillator and radioactive source. The attenuation of particles traveling through a thin film for preventing the detector from being contaminated was experimentally estimated. It is concluded from our investigation that the phoswich detector developed can provide a sufficient alpha/beta-ray discrimination. The application of a thin film for preventing the detector from being contaminated was proven to be feasible.

  13. Empirical description of beta-delayed fission partial half-lives

    OpenAIRE

    Ghys, Lars; Andreyev, A.N.; Antalic, S; Huyse, Mark; Van Duppen, Piet

    2015-01-01

    Background: The process of beta-delayed fission (bDF) provides a versatile tool to study low-energy fission in nuclei far away from the beta-stability line, especially for nuclei which do not fission spontaneously. Purpose: The aim of this paper is to investigate systematic trends in bDF partial half-lives. Method: A semi-phenomenological framework was developed to systematically account for the behavior of bDF partial half-lives. Results: The bDF partial half-life appears to exponentially de...

  14. First observation of $\\beta$-delayed $\\gamma$-proton decay in the $T_z$ = -2, $^{56}$Zn nucleus

    CERN Document Server

    Orrigo, S E A; Fujita, Y; Blank, B; Gelletly, W; Agramunt, J; Algora, A; Ascher, P; Bilgier, B; Cáceres, L; Cakirli, R B; Fujita, H; Ganioğlu, E; Gerbaux, M; Giovinazzo, J; Grévy, S; Kamalou, O; Kozer, H C; Kucuk, L; Kurtukian-Nieto, T; Molina, F; Popescu, L; Rogers, A M; Susoy, G; Stodel, C; Suzuki, T; Tamii, A; Thomas, J C

    2014-01-01

    We report on the first experimental observation of a very exotic decay mode at the proton drip-line, the $\\beta$-delayed $\\gamma$-proton decay, clearly seen in the $\\beta$ decay of the $T_z$ = -2, $^{56}$Zn nucleus. The $^{56}$Zn half-life and decay scheme have been determined. The decay proceeds by $\\beta$-delayed proton emission and $\\beta$-delayed $\\gamma$ de-excitation. The exotic $\\beta$-delayed $\\gamma$-proton emission was also detected in three cases. It affects the usual determination of the Gamow-Teller (GT) strength. Absolute Fermi and GT strengths have been deduced. Evidence for fragmentation of the Fermi strength due to isospin mixing is found.

  15. Bacteria Delay the Jamming of Particles at Microchannel Bottlenecks.

    Science.gov (United States)

    Sendekie, Zenamarkos Bantie; Gaveau, Arthur; Lammertink, Rob G H; Bacchin, Patrice

    2016-01-01

    Clogging of channels by complex systems such as mixtures of colloidal and biological particles is commonly encountered in different applications. In this work, we analyze and compare the clogging mechanisms and dynamics by pure and mixture suspensions of polystyrene latex particles and Escherichia coli by coupling fluorescent microscopic observation and dynamic permeability measurements in microfluidic filters. Pure particles filtration leads to arches and deposit formation in the upstream side of the microfilter while pure bacteria form streamers in the downstream zone. When mixing particle and bacteria, an unexpected phenomenon occurs: the clogging dynamics is significantly delayed. This phenomenon is related to apparent "slippery" interactions between the particles and the bacteria. These interactions limit the arches formation at the channels entrances and favour the formation of dendritic structures on the pillars between the channels. When these dendrites are eroded by the flow, fragments of the deposit are dragged towards the channels entrances. However, these bacteria/particles clusters being lubricated by the slippery interactions are deformed and stretched by the shear thus facilitating their passage through the microchannels. PMID:27510611

  16. Competition between $\\beta$-delayed proton and $\\beta$-delayed $\\gamma$ decay of the exotic $T_z$ = -2 nucleus $^{56}$Zn and fragmentation of the IAS

    CERN Document Server

    Rubio, B; Fujita, Y; Blank, B; Gelletly, W; Agramunt, J; Algora, A; Ascher, P; Bilgier, B; Cáceres, L; Cakirli, R B; Fujita, H; Ganioglu, E; Gerbaux, M; Giovinazzo, J; Grévy, S; Kamalou, O; Kozer, H C; Kucuk, L; Kurtukian-Nieto, T; Molina, F; Popescu, L; Rogers, A M; Susoy, G; Stodel, C; Suzuki, T; Tamii, A; Thomas, J C

    2015-01-01

    A very exotic decay mode at the proton drip-line, $\\beta$-delayed $\\gamma$-proton decay, has been observed in the $\\beta$ decay of the $T_z$ = -2 nucleus $^{56}$Zn. Three $\\gamma$-proton sequences have been observed following the $\\beta$ decay. The fragmentation of the IAS in $^{56}$Cu has also been observed for the first time. The results were reported in a recent publication. At the time of publication the authors were puzzled by the competition between proton and $\\gamma$ decays from the main component of the IAS. Here we outline a possible explanation based on the nuclear structure properties of the three nuclei involved, namely $^{56}$Zn, $^{56}$Cu and $^{55}$Ni, close to the doubly magic nucleus $^{56}$Ni. From the fragmentation of the Fermi strength and the excitation energy of the two populated 0$^{+}$ states we could deduce the off-diagonal matrix element of the charge-dependent part of the Hamiltonian responsible for the mixing. These results are compared with the decay of $^{55}$Cu with one proton ...

  17. Delayed Proton Emission in the A=70 Region, a Strobe for Level Density and Particle Width

    CERN Multimedia

    2002-01-01

    The delayed particle emission, which is a characteristic signature of the most exotic nuclei decay, provides a wide variety of spectroscopic information among which level density, and gives in some cases access to selected microscopic structures. In regard to these two aspects the $\\beta^+$-EC delayed proton emission in the A=70 neutron deficient mass region is of special interest to be investigated. Indeed, in this area located close to the proton drip line and along the N=Z line, the delayed proton emission constitutes an access to level density in the Q$_{EC}$-S$_p$ window of the emitting nucleus. Moreover, the unbound states populated by the EC process are expected to exhibit lifetimes in the vicinity of the K electronic shell filling time ($\\tau\\!\\sim\\!2\\times10^{-16}$s) and so the particle widths can be reached via proton X-ray coincidence measurements (PXCT). From theoretical approaches strongly deformed low-spin proton unbound levels which may be populated in the T$_Z$ = 1/2 precursors decay are predi...

  18. Beta-delayed proton emission in neutron-deficient lanthanide isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Wilmarth, P.A.

    1988-09-30

    Forty-two ..beta..-delayed proton precursors with 56less than or equal toZless than or equal to71 and 63less than or equal toNless than or equal to83 were produced in heavy-ion reactions at the Lawrence Berkeley Laboratory SuperHILAC and their radioactive decay properties studied at the on-line mass separation facility OASIS. Twenty-five isotopes and eight delayed proton branches were identified for the first time. Delayed proton energy spectra and proton coincident ..gamma..-ray and x-ray spectra were measured for all precursors. In a few cases, proton branching ratios were also determined. The precursor mass numbers were determined by the separator, while the proton coincident x-ray energies provided unambiguous Z identifications. The proton coincident ..gamma..-ray intensities were used to extract final state branching ratios. Proton emission from ground and isomeric states was observed in many cases. The majority of the delayed proton spectra exhibited the smooth bell-shaped distribution expected for heavy mass precursors. The experimental results were compared to statistical model calculations using standard parameter sets. Calculations using Nilsson model/RPA ..beta..-strength functions were found to reproduce the spectral shapes and branching ratios better than calculations using either constant or gross theory ..beta..-strength functions. Precursor half-life predictions from the Nilsson model/RPA ..beta..-strength functions were also in better agreement with the measured half-lives than were gross theory predictions. The ratios of positron coincident proton intensities to total proton intensities were used to determine Q/sub EC/-B/sub p/ values for several precursors near N=82. The statistical model calculations were not able to reproduce the experimental results for N=81 precursors. 154 refs., 82 figs., 19 tabs.

  19. New Beta-delayed Neutron Measurements in the Light-mass Fission Group

    International Nuclear Information System (INIS)

    A new accurate determination of beta-delayed neutron emission probabilities from nuclei in the low mass region of the light fission group has been performed. The measurements were carried out using the BELEN 4π neutron counter at the IGISOL-JYFL mass separator in combination with a Penning trap. The new results significantly improve the uncertainties of neutron emission probabilities for 91Br, 86As, 85As, and 85Ge nuclei

  20. Measurement quality assurance for beta particle calibrations at NIST

    Energy Technology Data Exchange (ETDEWEB)

    Soares, C.G.; Pruitt, J.S. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    1993-12-31

    Standardized beta-particle fields have been established in an international standard and have been adopted for use in several U.S. dosimeter and instrument testing standards. Calibration methods and measurement quality assurance procedures employed at the National Institute of Standards and Technology (NIST) for beta-particle calibrations in these reference fields are discussed. The calibration facility including the NIST-automated extrapolation ionization chamber is described, and some sample results of calibrations are shown. Methods for establishing and maintaining traceability to NIST of secondary laboratories are discussed. Currently, there are problems in finding a good method for routine testing of traceability to NIST. Some examples of past testing methods are given and solutions to this problem are proposed.

  1. Study of Beta-delayed Neutrons near 78Ni using VANDLE

    Science.gov (United States)

    Paulauskas, S.; Madurga, M.; Grzywacz, R.; Peters, W.; Vandle Collaboration

    2015-10-01

    As nuclei become more neutron rich, the nuclear structure changes their properties. For example, beta decays will access increasingly more neutron unbound states. The measurement of neutrons emitted from these states is critical, as beta-delayed neutron emission becomes a dominating decay mode. To this end, the Versatile Array of Neutron Detectors at Low Energy (VANDLE) measures the energy of neutrons emitted from excited states above the neutron separation energy populated through beta decay or transfer reactions. The time-of-flight technique determines the energy, which requires a time resolution on the order of 1 ns. In addition, the detector requires a low detection threshold to measure neutron energies of 100 keV or lower. A successful experimental campaign at the Holifield Radioactive Ion Beam Facility, using ions produced via proton induced fission on 238U, has yielded results on beta-delayed neutrons emitted from isotopes near 78Ni. Of particular interest, is the observation of low-energy neutrons emitted from states well above the neutron separation energy. Results from this experiment will be presented. This research was sponsored in part by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Cooperative Agreement No. DE-FG52-08NA28552 and the Office of Nuclear Physics.

  2. Studies of $\\beta$-delayed two-proton emission : The cases of $^{31}$Ar and $^{35}$Ca

    CERN Multimedia

    Riisager, K; Jokinen, A; Canchel, G; Heinz, A M; Jonson, B N G; Dominguez reyes, R R; Koldste, G T; Fraile prieto, L M; Nilsson, T; Audirac, L L

    2008-01-01

    We propose to perform detailed studies of the decays of the two dripline nuclei $^{31}$Ar and $^{35}$Ca. This will allow an in-depth study in the process of $\\beta$-delayed two-proton emission ($\\beta$2p); as well as provide important information on resonances in $^{30}$S and $^{34}$Ar relevant for the astrophysical rp-process.

  3. Study of nuclei far from the stability line. Mass measurements and emission analysis of delayed particles

    International Nuclear Information System (INIS)

    Experiments were made at Isolde (CERN) Strasbourg and Orsay tandem, and Ganil. Decay mode of delayed-neutron and delayed-proton emitter nuclei with mass around 30 and 70 (32Ar, 33Ar, 65Ge, 69Se, 29Na, 30Na). Energy and information on structure of bound states of daughter nuclei and on Gamow-Teller transition strength. Analysis by autocorrelation method of delayed-proton energy spectra of 65Ge and 69Se allows to set the level density above the separation energy of the particle in the emitter nucleus. Lifetime of unbound states (in 10-6 second field) in 69As can be estimated. Mass excess of 49K, 50K and 42Cl was determined experimentally; a new measurement was made for 40Cl. Mass excess of 147Gd was measured again with a two body reaction 144Sm (12C, 9Be)147Gd. Theoretical and experimental continuation of previous work was developed on heavy isotopes of iron and nickel. The half-life of the doubly-magic nucleus 68Ni first excited state was measured and compared to theoretical calculations. Beta decay of heavy isotopes of elements from chromium to zinc was also studied to measure their half-life

  4. $\\beta$-delayed neutrons from oriented $^{137,139}$I and $^{87,89}$Br nuclei

    CERN Document Server

    Grzywacz, Robert; Stone, Nicholas; Köster, Ulli; Singh, Barlaj; Bingham, Carrol; Gaulard, S; Kolos, Karolina; Madurga, Miguel; Nikolov, J; Otsubo, T; Roccia, S; Veskovic, Miroslav; Walker, Phil; Walters, William

    2013-01-01

    We propose a world-­‐first measurement of the angular distribution of $\\beta$-­‐delayed n and $\\gamma$- radiation from oriented $^{137, 139}$I and $^{87,89}$Br nuclei, polarised at low temperature at the NICOLE facility. $\\beta$-­‐delayed neutron emission is an increasingly important decay mechanism as the drip line is approached and its detailed understanding is essential to phenomena as fundamental as the r‐process and practical as the safe operation of nuclear power reactors. The experiments offer sensitive tests of theoretical input concerning the allowed and first-­‐forbidden $\\beta$‐decay strength, the spin-­‐density of neutron emitting states and the partial wave barrier penetration as a function of nuclear deformation. In $^{137}$I and $^{87}$Br the decay feeds predominantly the ground state of the daughters $^{136}$Xe and $^{86}$Kr whereas in $^{139}$I and $^{89}$Br we will explore the use of n-$\\gamma$- coincidence to study neutron transitions to the first and second excited state...

  5. $\\beta$-delayed neutrons from oriented $^{137,139}$I and $^{87,89}$Br nuclei

    CERN Multimedia

    We propose a world-first measurement of the angular distribution of $\\beta$‐delayed n and $\\gamma$-radiation from oriented $^{137, 139}$I and $^{87,89}$Br nuclei, polarised at low temperature at the NICOLE facility. $\\beta$­-delayed neutron emission is an increasingly important decay mechanism as the drip line is approached and its detailed understanding is essential to phenomena as fundamental as the r‐process and practical as the safe operation of nuclear power reactors. The experiments offer sensitive tests of theoretical input concerning the allowed and first­‐forbidden $\\beta$‐decay strength, the spin-density of neutron emitting states and the partial wave barrier penetration as a function of nuclear deformation. In $^{137}$I and $^{87}$Br the decay feeds predominantly the ground state of the daughters $^{136}$Xe and $^{86}$Kr whereas in $^{139}$I and $^{89}$Br we will explore the use of n-$\\gamma$- coincidence to study neutron transitions to the first and second excited states in the daughters...

  6. Empirical description of beta-delayed fission partial half-lives

    CERN Document Server

    Ghys, L; Antalic, S; Huyse, M; Van Duppen, P

    2015-01-01

    Background: The process of beta-delayed fission (bDF) provides a versatile tool to study low-energy fission in nuclei far away from the beta-stability line, especially for nuclei which do not fission spontaneously. Purpose: The aim of this paper is to investigate systematic trends in bDF partial half-lives. Method: A semi-phenomenological framework was developed to systematically account for the behavior of bDF partial half-lives. Results: The bDF partial half-life appears to exponentially depend on the difference between the Q value for beta decay of the parent nucleus and the fission-barrier energy of the daughter (after beta decay) product. Such dependence was found to arise naturally from some simple theoretical considerations. Conclusions: This systematic trend was confirmed for experimental bDF partial half-lives spanning over 7 orders of magnitudes when using fission barriers calculated from either the Thomas-Fermi or the liquid-drop fission model. The same dependence was also observed, although less p...

  7. $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with radioactive At beams

    CERN Multimedia

    We propose to study the $\\beta$-delayed fission, laser spectroscopy and radioactive decay of the newly available pure beams of neutron-deficient and neutron-rich astatine (Z=85) isotopes. The fission probability and the fission fragment distribution of the even-even isotopes $^{194,196}$Po following the $\\beta$-decay of the isotopes $^{194,196}$At will be studied with the Windmill setup. In-source laser spectroscopy will be performed on the entire astatine isotopic chain, using a combination of the Windmill setup, ISOLTRAP MR-ToF and ISOLDE Faraday. Radioactive decay data will be acquired at the Windmill setup throughout those studies and contribute to the global understanding of the phenomenon of shape coexistence in the neutron-deficient lead region.

  8. Fine structure in the beta-delayed proton decay of 33Ar

    International Nuclear Information System (INIS)

    Low-energy beta-delayed protons from 33Ar have been measured for the first time. The data reveal states, which, despite unfavourable barrier penetrability values, strongly decay to the first excited 2+ state in 32S. The observation is discussed in terms of the standard shell model. A natural explanation is provided by the large spectroscopic amplitudes, involving s1/2 and d3/2 orbitals, as well as the l=0 barrier penetrability, favouring the decay to the 2+ state. (orig.)

  9. On evaluated nuclear data for beta-delayed gamma rays following of special nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Mencarini, Leonardo de H.; Caldeira, Alexandre D., E-mail: mencarini@ieav.cta.b, E-mail: alexdc@ieav.cta.b [Instituto de Estudos Avancados (IEAv/CTA), Sao Jose dos Campos, SP (Brazil)

    2011-07-01

    In this paper, a new type of information available in ENDF is discussed. During a consistency check of the evaluated nuclear data library ENDF/B-VII.0 performed at the Nuclear Data Subdivision of the Institute for Advanced Studies, the size of the files for some materials drew the attention of one of the authors. Almost 94 % of all available information for these special nuclear materials is used to represent the beta-delayed gamma rays following fission. This is the first time this information is included in an ENDF version. (author)

  10. On evaluated nuclear data for beta-delayed gamma rays following of special nuclear materials

    International Nuclear Information System (INIS)

    In this paper, a new type of information available in ENDF is discussed. During a consistency check of the evaluated nuclear data library ENDF/B-VII.0 performed at the Nuclear Data Subdivision of the Institute for Advanced Studies, the size of the files for some materials drew the attention of one of the authors. Almost 94 % of all available information for these special nuclear materials is used to represent the beta-delayed gamma rays following fission. This is the first time this information is included in an ENDF version. (author)

  11. Summary Report of Consultants' Meeting on Beta-Delayed Neutron Emission Evaluation

    International Nuclear Information System (INIS)

    A summary is given of a Consultants' Meeting assembled to assess the viability of a new IAEA Co-ordinated Research Project (CRP) on Beta-delayed neutron emission evaluation. The current status of the field was reviewed, cases in which new measurements are needed were identified and the current theoretical models were examined. The best known cases were selected as standards and were assessed and preliminary best values of the emission probabilities were obtained. The need of such a CRP was strongly agreed. Both the technical discussions and the expected outcome of such a project are described, along with detailed recommendations for its implementation. (author)

  12. First Measurements with the BEta deLayEd Neutron Detector (BELEN-20) at JYFLTRAP

    International Nuclear Information System (INIS)

    A prototype version of the BEta deLayEd Neutron detector, which is being developed for the FAIR/DESPEC experiment, has been used for the first time in an experiment at JYFL (Finland). This detector is based on 3He counters and its first run was primarily intended to commission the detector and verify the working principles for future experiments. A new triggerless DAQ has been developed for these measurements. This DAQ time-stamps the events and allows complete flexibility to construct correlations offline. An isotopically pure beam was obtained using the JYFLTRAP Penning trap setup at the IGISOL facility and it was implanted on a movable tape placed in the centre of the BELEN-20 detector. The measurements were performed for known delayed neutron emitters of interest for nuclear power generation: 88Br, 94,95Rb, 138I. The characteristics of the BELEN-20 detector and the first experiment at JYFL are presented in this paper.

  13. First-forbidden $\\mathbf{\\beta}$-decay rates, energy rates of $\\beta$-delayed neutrons and probability of $\\beta$-delayed neutron emissions for neutron-rich nickel isotopes

    CERN Document Server

    Nabi, Jameel-Un; Iftikhar, Zafar

    2016-01-01

    First-forbidden (FF) transitions can play an important role in decreasing the calculated half-lives specially in environments where allowed Gamow-Teller (GT) transitions are unfavored. Of special mention is the case of neutron-rich nuclei where, due to phase-space amplification, FF transitions are much favored. We calculate the allowed GT transitions in various pn-QRPA models for even-even neutron-rich isotopes of nickel. Here we also study the effect of deformation on the calculated GT strengths. The FF transitions for even-even neutron-rich isotopes of nickel are calculated assuming the nuclei to be spherical. Later we take into account deformation of nuclei and calculate GT + unique FF transitions, stellar $\\beta$-decay rates, energy rate of $\\beta$-delayed neutrons and probability of $\\beta$-delayed neutron emissions. The calculated half-lives are in excellent agreement with measured ones and might contribute in speeding-up of the $r$-matter flow.

  14. beta-delayed fission from sup 2 sup 3 sup 0 Ac

    CERN Document Server

    Yang Wei Fan; Xu Yan Bing; Xong Bing; Pan Qiang Yan; He Jian Jun; Xiao Yong Hou; Li Yi

    2002-01-01

    ThO sub 2 is irradiated with 60 MeV/u sup 1 sup 8 O beams. sup 2 sup 3 sup 0 Ra is produced via the multi-nucleon transfer and dissipative fragmentation reactions of the target. sup 2 sup 3 sup 0 Ra is radio-chemical separated from ThO sub 2 and the other reaction products. The thin Ra sources are prepared. The mica fission track detectors are exposed to the Ra sources. gamma-rays of Ra decay in the sources are measured by a HPGe detector. The mica foil is etched in HF solution. The etched mica foil is scanned with an optical microscope. The fission tracks that should come from beta-delayed fission of sup 2 sup 3 sup 0 Ac are observed. The beta-delayed fission probability of sup 2 sup 3 sup 0 Ac is determined to be (1.19 +- 0.85) x 10 sup - sup 8

  15. Beta-decay half-lives and beta-delayed neutron emission probabilities of nuclei in the region below A=110, relevant for the r-process

    CERN Document Server

    Pereira, J; Aprahamian, A; Arndt, O; Becerril, A; Elliot, T; Estrade, A; Galaviz, D; Kessler, R; Kratz, K -L; Lorusso, G; Mantica, P F; Matos, M; Møller, P; Montes, F; Pfeiffer, B; Schatz, H; Schertz, F; Schnorrenberger, L; Smith, E; Stolz, A; Quinn, M; Walters, W B; Wöhr, A

    2009-01-01

    Measurements of the beta-decay properties of r-process nuclei below A=110 have been completed at the National Superconducting Cyclotron Laboratory, at Michigan State University. Beta-decay half-lives for Y-105, Zr-106,107 and Mo-111, along with beta-delayed neutron emission probabilities of Y-104, Mo-109,110 and upper limits for Y-105, Zr-103,104,105,106,107 and Mo-108,111 have been measured for the first time. Studies on the basis of the quasi-random phase approximation are used to analyze the ground-state deformation of these nuclei.

  16. $\\beta$-delayed fission in proton-rich nuclei in the lead region

    CERN Document Server

    AUTHOR|(CDS)2085005; Huyse, Mark; Popescu, Lucia

    Nuclear fission is the breakup of an atomic nucleus into two (sometimes three) fragments, thereby releasing a large amount of energy. Soon after its discovery in the late 1930’s, the gross properties of the fission phenomenon were explained by macroscopic nuclear models. Certain features however, such as asymmetric fission-fragment mass distributions in the actinide region, require the inclusion of microscopic effects. This interplay of the microscopic motion of individual nucleons on this macroscopic process is, until today, not yet fully understood. The phenomenon of fission has therefore been of recurring interest for both theoretical and experimental studies. This thesis work focuses on the $\\beta$-delayed fission ($\\beta$DF) process, an excellent tool to study low-energy fission of exotic nuclei, which was discovered in 1966 in the actinide region. In this two-step process, a precursor nucleus first undergoes $\\beta$-decay to an excited level in the daughter nucleus, which may subsequently fission. Rec...

  17. Beta particles sensitivity of an all-carbon detector

    International Nuclear Information System (INIS)

    The response of high quality polycrystalline diamond pixel detectors to 90Sr beta particles is reported. Laser induced surface graphitization was used to realize 36 conductive contacts with 1 mm×1 mm area each, pitch 1.2 mm, on one detector side whereas a 8 mm×8 mm large area graphite contact was realized on the other face for grounding or biasing. A proximity board was used to hold the matrix, the amplifiers and to bond nine pixels to test homogeneity of response among 36 detector pixels. Two configurations were used to test charge collection uniformity and signal dependence on voltage. Both configurations showed noise pedestal fitted with a Gaussian curve of 1150 equivalent electrons (1σ) and typical beta source particles spectrum. Reversing the bias polarity the pulse height distribution does not change and the saturation of most probable value of charge collection was observed around ±200 V (0.4 V/μm) with reasonable pixel response uniformity equal to a most probable value 1.28±0.05 fC. The charge collection efficiency (CCE) measurement was implemented using coincidence mode acquisition with an external trigger made by a commercial polycrystalline diamond slab. The detector shows a CCE=0.59 estimated using the 1 mm2 large graphite pixel. The information earned with this first prototype will be used to design the new board with amplifying electronics for reading all 36 pixels at a time and perform experiments with monochromatic high energy electrons

  18. A Novel Approach to β-delayed Neutron Spectroscopy Using the Beta-decay Paul Trap

    International Nuclear Information System (INIS)

    A new approach to β-delayed neutron spectroscopy has been demonstrated that circumvents the many limitations associated with neutron detection by instead inferring the decay branching ratios and energy spectra of the emitted neutrons by studying the nuclear recoil. Using the Beta-decay Paul Trap, fission-product ions were trapped and confined to within a 1-mm3 volume under vacuum using only electric fields. Results from recent measurements of 137I+ and plans for development of a dedicated ion trap for future experiments using the intense fission fragment beams from the Californium Rare Isotope Breeder Upgrade (CARIBU) facility at Argonne National Laboratory are summarized. The improved nuclear data that can be collected is needed in many fields of basic and applied science such as nuclear energy, nuclear astrophysics, and stockpile stewardship

  19. The Beta-Delayed Proton and Gamma Decay of 27P for Nuclear Astrophysics

    Science.gov (United States)

    Simmons, E.; Trache, L.; Banu, A.; McCleskey, M.; Roeder, B.; Spiridon, A.; Tribble, R. E.; Davinson, T.; Woods, P. J.; Lotay, G. J.; Wallace, J.; Doherty, D.; Saastamoinen, A.

    2013-03-01

    The creation site of 26Al is still under debate. It is thought to be produced in hydrogen burning and in explosive helium burning in novae and supernovae, and possibly also in the H-burning in outer shells of red giant stars. Also, the reactions for its creation or destruction are not completely known. When 26Al is created in novae, the reaction chain is: 24Mg(p,γ)25AI(β+v)25 Mg(p,γ)26Al, but this chain can be by-passed by another chain, 25Al(p, γ)26Si(p, γ)27P and it can also be destroyed directly. The reaction 26m Al (p, γ)27 Si* is another avenue to bypass the production of 26Al and it is dominated by resonant capture. We find and study these resonances by an indirect method, through the beta-decay of 27P. A clean and abundant source of 27P was produced for the first time and separated with MARS. A new implantation-decay station which allows increased efficiency for low energy protons and for high-energy gamma-rays was used. We measured gamma-rays and beta-delayed protons emitted from states above the proton threshold in the daughter nucleus 27Si to identify and characterize the resonances. The lifetime of 27P was also measured with accuracy under 2%.

  20. Low Cerebrospinal Fluid Amyloid-Beta Concentration Is Associated with Poorer Delayed Memory Recall in Women

    Directory of Open Access Journals (Sweden)

    Fanni Haapalinna

    2016-07-01

    Full Text Available Background: Data on the association of memory performance with cerebrospinal fluid (CSF biomarkers of Alzheimer's disease (AD are inconsistent. The Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery (CERAD-NB is a commonly used validated cognitive tool; however, only few studies have examined its relationship with CSF biomarkers for AD. We studied the correlation of pathological changes in CSF biomarkers with various CERAD-NB subtests and total scores. Methods: Out of 79 subjects (36 men, mean age 70.5 years, 63 had undergone an assessment of cognitive status with CERAD-NB and a CSF biomarker analysis due to a suspected memory disorder, and 16 were controls with no memory complaint.Results: In women we found a significant correlation between CSF amyloid-beta (Aβ1-42 and several subtests measuring delayed recall. Word List Recall correlated with all markers: Aβ1-42 (r = 0.323, p = 0.035, tau (r = -0.304, p = 0.050 and hyperphosphorylated tau (r = -0.331, p = 0.046. No such correlations were found in men. Conclusions: CSF biomarkers correlate with delayed memory scores in CERAD-NB in women, and women may have more actual AD pathology at the time of the investigations than men.

  1. Parameter estimation for time-delay chaotic system by particle swarm optimization

    International Nuclear Information System (INIS)

    The knowledge about time delays and parameters is very important for control and synchronization of time-delay chaotic system. In this paper, parameter estimation for time-delay chaotic system is given by treating the time delay as an additional parameter. The parameter estimation is converted to an optimization problem, which finds a best parameter combination such that an objective function is minimized. Particle swarm optimization (PSO) is used to optimize the objective function through particles' cooperation and evolution. Two illustrative examples are given to show the validity of the proposed method.

  2. Particle filter with one-step randomly delayed measurements and unknown latency probability

    Science.gov (United States)

    Zhang, Yonggang; Huang, Yulong; Li, Ning; Zhao, Lin

    2016-01-01

    In this paper, a new particle filter is proposed to solve the nonlinear and non-Gaussian filtering problem when measurements are randomly delayed by one sampling time and the latency probability of the delay is unknown. In the proposed method, particles and their weights are updated in Bayesian filtering framework by considering the randomly delayed measurement model, and the latency probability is identified by maximum likelihood criterion. The superior performance of the proposed particle filter as compared with existing methods and the effectiveness of the proposed identification method of latency probability are both illustrated in two numerical examples concerning univariate non-stationary growth model and bearing only tracking.

  3. The rp-process and new measurements of $\\beta$-delayed proton decay of light Ag and Cd isotopes

    CERN Document Server

    Raimann, G; Boyd, R N; Cano-Ott, D; Collatz, R; Guglielmetti, A; Hellström, M; Hencheck, M; Hu, Z; Janas, Z; Karny, M; Kirchner, R; Morford, L J; Morrissey, D J; Roeckl, E; Schmidt, K; Szerypo, J; Weber, A

    1996-01-01

    Recent network calculations suggest that a high temperature rp-process could explain the abundances of light Mo and Ru isotopes, which have long challenged models of p-process nuclide production. Important ingredients to network calculations involving unstable nuclei near and at the proton drip line are \\beta-halflives and decay modes, i.e., whether or not \\beta-delayed proton decay takes place. Of particular importance to these network calculation are the proton-rich isotopes ^{96}Ag, ^{98}Ag, ^{96}Cd and ^{98}Cd. We report on recent measurements of \\beta-delayed proton branching ratios for ^{96}Ag, ^{98}Ag, and ^{98}Cd at the on-line mass separator at GSI.

  4. Transverse Polarization of Beta Particles from Polarized Nuclei.

    Science.gov (United States)

    Markey, John Kevin

    In this thesis an experiment to measure the transverse polariza- tion of electrons from the decay of polarized ('60)Co is presented. The result P = (1.2 (+OR-) 0.2) (gamma)SQRT.(1 - v('2)/c('2)) /J is consistent with the predicted polarization based on the V - A theory of the weak inter- action and the Weinberg, Salam, Glashow model. The theoretical prediction is P = (gamma)SQRT.(1 - v('2)/c('2)) /J where (gamma) = SQRT.(1 - z('2) (alpha)('2)). This is the first measurement of the transverse polarization of beta particles from the decay of polarized nuclei. The polarization of the electrons was measured by scattering them from gold foil and detecting the scattering asymmetry predicted by Mott scattering theory. ('60)Co nuclei were polarized by embedding them in a ferromagnetic host where they feel a strong hyperfine field. The host foil was attached to a dilution refrigerator to lower the entropy of the nuclei and allow for nuclear polarization.

  5. Delay induced instabilities in self-propelling swarming particles

    Science.gov (United States)

    Forgoston, Eric; Schwartz, Ira

    2008-03-01

    We consider a general model of self-propelling biological or artificial individuals interacting through a pairwise attractive force in a two-dimensional system in the presence of noise and communication time delay. Previous work has shown that a large enough noise intensity will cause a translating swarm of individuals to transition to a rotating swarm with a stationary center of mass. In this work, we use numerical simulations to show that with the addition of a time delay, the model possesses a transition that depends on the size of the coupling parameter. This transition is independent of the swarm state (traveling or rotating) and is characterized by the alignment of all of the individuals along with a swarm oscillation. By considering the mean field equations without noise, we show that the time delay induced transition is associated with a Hopf bifurcation. The analytical result yields good agreement with numerical computations of the value of the coupling parameter at the Hopf point.

  6. Optimization of the measurement of urinary beta transmitters by scintillation liquid with delay before burst

    International Nuclear Information System (INIS)

    In a follow-up of radio-toxicological staff working with β-emitting sources through bioassays, liquid scintillation is the best method to achieve this type of analysis. As the elements are present in trace amounts in urine, it is important to optimize the methods to achieve the best sensitivity. In recent years, less polluting and less toxic scintillating liquids have become available and should eventually replace the current ones. Besides these new features, they take longer to dissipate the energy emitted by the fluorescence photon resulting from the interaction between the β-particle and the scintillators. This has a direct impact on the quality of the detection and requires setting optimal detection parameters; in particular, the Delay Before Burst must be carefully tuned. This study aims at showing the importance of tuning the Delay Before Burst parameter to optimize the detection limits in liquid scintillation. It covers the whole range of energies of β radiation measured (3H, 14C and 89Sr) and two types of scintillating liquid used in the laboratory: one current type, the Pico-Fluor 40, and a new one, the Ultima Gold LTT. (authors)

  7. About the problem of the delays between particles belonging to the cosmic radiation

    International Nuclear Information System (INIS)

    After having examined briefly the problem of the delays who can appear between particles of high energy, issued of a same mother particle, we studied in a more details the case of the loaded particles, loosing their energy by ionization. The delay that settles between two particles of mass M belonging to this last species is defined by the difference between the times that they take to do the same distance. In the vacuum, the delays can reach any values. But, when the particles diffuse themselves in a middle absorbing, the delays stretch toward a definite limit whatever the initial energies of the particles is. One demonstrates that the maximum delay is given by (Δt)max ≅ 0,6 E0 / cKmin, where E0 = Mc2 represents the energy to the rest of the particle and Kmin the minimum loss of energy by cm of course in the given middle. For example, in the case of the protons crossing different absorbing surroundings, the values of (Δt)max for air (Tpn), water, the Al and the Pb are respectively equal to 8,3.10-6, 9,7.10-9, 45.10-9 and 1,6 10-9 dry. The corresponding values of (Δt)max for the electrons, are the order of 10-9 dry for air and the order of 10-12 dry for the condensed surroundings. It results that, if the particles belonging has a sheaf demonstrated between them of the superior delays to those that are indicate, the fact would constitute a sufficient proof of the existence of heavy particles to the breast of the sheaf. Otherwise, the relation that joins (Δt)max to the mass M could act as basis to a method of mass spectrography of the big energy particles. (author)

  8. Summary Report of 1st Research Coordination Meeting on Development of Reference Database for Beta-delayed Neutron Emission

    International Nuclear Information System (INIS)

    A summary is given of the 1st Research Coordination Meeting of the new IAEA Coordinated Research Project (CRP) on Development of a Reference Database for Beta-delayed neutron emission data. Participants presented their work, reviewed the current status of the field with regards to individual precursors and aggregate data, and discussed the scope of the work to be undertaken. A list of priorities and task assignments was produced. (author)

  9. Statistical effects in beta-delayed neutron emission from fission product nuclides

    International Nuclear Information System (INIS)

    The delayed neutron spectra for the precursors Rb-93, 94, 95, 96, 97 and Cs-145 were measured by use of the on-line isotope separator facility TRISTAN and a time-of-flight (TOF) spectrometer. Flight paths were used that provided, for energies below 70 keV, a FWHM energy resolution between 2 and 4 percent. Each spectrum showed discrete neutron peaks below 156 keV, with as many as 26 in the Rb-95 spectra. Level densities near the neutron binding energy in the neutron-emitting nuclide were deduced using a missing-level indicator based on a Porter-Thomas distribution of neutron peak intensities. The resulting level density data were compared to the predictions of the Gilbert and Cameron formulism and to those of Dilg, Schantl, Vonach and Uhl. Comparisons were made between the empirically-based level parameter a and the values predicted by each model for Sr-93, 94, 95, 97 and Ba-145. The two models appear, within the uncertainties, to be equally capable of describing these neutron-rich nuclides and equally as capable for them as they are for nuclides in the valley of beta stability. Measurements of the neutron strength function are sometimes possible with the present TOF system for neutron decays with competing neutron branches to levels in the grandchild nucleus. A value for the d-wave strength function of Sr-96 is found to be (4.2 +- 1.1)/104. Improvements in the TOF system, allowing the measurement of the neutron strength function for the more general case, are discussed. 72 refs., 56 figs., 16 tabs

  10. Delayed fission

    International Nuclear Information System (INIS)

    Delayed fission is a nuclear process that couples beta decay and fission. In the delayed fission process, a parent nucleus undergoes beta decay or electron capture and thus populates excited states in the daughter nucleus. This review covers experimental methods for detecting and measuring delayed fission. Experimental results (ECDF activities and beta-DF activities) and theory are presented. The future prospects for study of delayed fission are discussed. 50 refs., 8 figs., 2 tabs

  11. Hot beta particles in the lung: Results from dogs exposed to fission product radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, F.F.; Griffith, W.C.; Hobbs, C.H. [and others

    1995-12-01

    The Chernobyl nuclear reactor accident resulted in the release of uranium dioxide fuel and fission product radionuclides into the environment with the fallout of respirable, highly radioactive particles that have been termed {open_quotes}hot beta particles.{close_quotes} There is concern that these hot beta particles (containing an average of 150-20,000 Bq/particle), when inhaled and deposited in the lung, may present an extraordinary hazard for the induction of lung cancer. We reviewed data from a group of studies in dogs exposed to different quantities of beta-emitting radionuclides with varied physical half-lives to determine if those that inhaled hot beta particles were at unusual risk for lung cancer. This analysis indicates that the average dose to the lung is adequate to predict biologic effects of lung cancer for inhaled beta-emitting radionuclides in the range of 5-50 Gy to the lung and with particle activities in the range of 0.10-50 Bq/particle.

  12. Total absorption γ-ray spectroscopy of beta delayed neutron emitters

    Science.gov (United States)

    Valencia, E.; Algora, A.; Tain, J. L.; Rice, S.; Agramunt, J.; Zakari-Issoufou, A.-A.; Porta, A.; Fallot, M.; Jordan, M. D.; Molina, F.; Estevez, E.; Bowry, M.; Bui, V. M.; Caballero-Folch, R.; Cano-Ott, D.; Eloma, V.; Eronen, T.; Garcia, A.; Gomez-Hornillos, M. B.; Gorlychev, V.; Hakala, J.; Jokinen, A.; Kondev, F. G.; Martinez, T.; Moore, I.; Rissanen, J.; Ńystö, J.; Penttilä, H.; Kankainen, A.; Rubio, B.; Gelletly, W.; Perez, A.; Podolyak, Zs.; Regan, P. H.; Farrelly, G. F.; Weber, C.; Mendoza, E.; Igisol People

    2013-06-01

    Preliminary results of the data analysis of the beta decay of 94Rb using a novel - segmented- total absorption spectrometer are shown in this contribution. This result is part of a systematic study of important contributors to the decay heat problem in nuclear reactors. In this particular case the goal is to determine the beta intensity distribution below the neutron separation energy and the gamma/beta competition above.

  13. Absorption of Beta Particles in Different Materials: An Undergraduate Experiment

    Science.gov (United States)

    La Rocca, Paola; Riggi, Francesco

    2009-01-01

    The absorption of beta rays from a radioactive source in different materials was investigated by the use of a simple setup based on a Geiger counter and a set of absorber sheets. The number of electrons traversing the material was measured as a function of its thickness. Detailed GEANT simulations were carried out to reproduce the obtained…

  14. Delayed release particles from vascular endothelial growth factor for repairing spinal cord ischemic injury of rats

    Institute of Scientific and Technical Information of China (English)

    CHEN Yang; LI Feng; XIAO Jian-de; LI Zhen-yu; YANG Lei; LUO Xin-le

    2007-01-01

    Objective:To study the effect of delayed release particles from vascular endothelial growth factor (VEGF)on the reparation of ischemic injury of spinal cord in rats. Methods:The spinal cord ischemia model of rats was established.The delayed release particles from VEGF were injected via the intubation of spinal subarachnoid space.The rehabilitation was observed by the assessment of unfold claw reflection,space between toes,spinal evoked potential (SEP) and motor evoked potential (MEP). Results:VEGF prompted SEP and MEP appearance,improved the motor function of hind limbs. Conclusions:VEGF can promote the rehabilitation of spinal cord ischemic injury of rats.

  15. Status of international benchmark experiment for effective delayed neutron fraction ({beta}eff)

    Energy Technology Data Exchange (ETDEWEB)

    Okajima, S.; Sakurai, T.; Mukaiyama, T. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    To improve the prediction accuracy of the {beta}eff, the program of the international benchmark experiment (Beta Effect Reactor Experiment for a New International Collaborative Evaluation: BERNICE) was planned. This program composed of two parts; BERNICE-MASURCA and BERNICE-FCA. The former one was carried out in the fast critical facility MASURCA of CEA, FRANCE between 1993 and 1994. The latter one started in the FCA, JAERI in 1995 and still is going. In these benchmark experiments, various experimental techniques have been applied for in-pile measurements of the {beta}eff. The accuracy of the measurements was better than 3%. (author)

  16. Delay-area trade-off for MPRM circuits based on hybrid discrete particle swarm optimization

    Institute of Scientific and Technical Information of China (English)

    Jiang Zhidi; Wang Zhenhai; Wang Pengjun

    2013-01-01

    Polarity optimization for mixed polarity Reed-Muller (MPRM) circuits is a combinatorial issue.Based on the study on discrete particle swarm optimization (DPSO) and mixed polarity,the corresponding relation between particle and mixed polarity is established,and the delay-area trade-off of large-scale MPRM circuits is proposed.Firstly,mutation operation and elitist strategy in genetic algorithm are incorporated into DPSO to further develop a hybrid DPSO (HDPSO).Then the best polarity for delay and area trade-off is searched for large-scale MPRM circuits by combining the HDPSO and a delay estimation model.Finally,the proposed algorithm is testified by MCNC Benchmarks.Experimental results show that HDPSO achieves a better convergence than DPSO in terms of search capability for large-scale MPRM circuits.

  17. Delay-area trade-off for MPRM circuits based on hybrid discrete particle swarm optimization

    International Nuclear Information System (INIS)

    Polarity optimization for mixed polarity Reed—Muller (MPRM) circuits is a combinatorial issue. Based on the study on discrete particle swarm optimization (DPSO) and mixed polarity, the corresponding relation between particle and mixed polarity is established, and the delay-area trade-off of large-scale MPRM circuits is proposed. Firstly, mutation operation and elitist strategy in genetic algorithm are incorporated into DPSO to further develop a hybrid DPSO (HDPSO). Then the best polarity for delay and area trade-off is searched for large-scale MPRM circuits by combining the HDPSO and a delay estimation model. Finally, the proposed algorithm is testified by MCNC Benchmarks. Experimental results show that HDPSO achieves a better convergence than DPSO in terms of search capability for large-scale MPRM circuits. (semiconductor integrated circuits)

  18. $\\beta$-decay and $\\beta$-delayed Neutron Emission Measurements at GSI-FRS Beyond N=126, for r-process Nucleosynthesis

    CERN Document Server

    Caballero-Folch, R; Cortès, G; Taín, J L; Agramunt, J; Algora, A; Ameil, F; Ayyad, Y; Benlliure, J; Bowry, M; Calviño, F; Cano-Ott, D; Davinson, T; Dillmann, I; Estrade, A; Evdokimov, A; Faestermann, T; Farinon, F; Galaviz, D; García-Ríos, A; Geissel, H; Gelletly, W; Gernhäuser, R; Gómez-Hornillos, M B; Guerrero, C; Heil, M; Hinke, C; Knöbel, R; Kojouharov, I; Kurcewicz, J; Kurz, N; Litvinov, Y; Maier, L; Marganiec, J; Marta, M; Martínez, T; Montes, F; Mukha, I; Napoli, D R; Nociforo, C; Paradela, C; Pietri, S; Podolyák, Zs; Prochazka, A; Rice, S; Riego, A; Rubio, B; Schaffner, H; Scheidenberger, C; Smith, K; Sokol, E; Steiger, K; Sun, B; Takechi, M; Testov, D; Weick, H; Wilson, E; Winfield, J S; Wood, R; Woods, P J; Yeremin, A

    2014-01-01

    New measurements of very exotic nuclei in the neutron-rich region beyond N=126 have been performed at the GSI facility with the fragment separator (FRS). The aim of the experiment is to determine half-lives and beta-delayed neutron emission branching ratios of isotopes of Hg, Tl and Pb in this region. This contribution summarizes final counting statistics for identification and for implantation, as well as the present status of the data analysis of the half-lives. In summary, isotopes of Pt, Au, Hg, Ti, Pb, Bi, Po, At, Rn and Fr were clearly identified and several of them (Hg208-211, Tl211-215, Pb214-218) were implanted with enough statistics to determine their half-lives. About half of them are expected to be neutron emitters, in such cases it will become possible to obtain the neutron emission probabilities, P-n.

  19. Alpha and beta particle induced scintillations in liquid and solid neon

    CERN Document Server

    Michniak, R A; McKinsey, D N; Doyle, J M

    2002-01-01

    Scintillations induced by alpha and beta particles in liquid and solid neon are studied and their light yield measured. Charged particle scintillation in neon is primarily in the extreme ultraviolet (EUV). We detect this EUV light by converting it to blue using a wavelength shifting fluor and detecting the blue light with a photomultiplier tube. It is observed that liquid neon is a somewhat less-efficient scintillator than liquid helium for both alpha and beta radiation while the light yield in solid neon is greater than in liquid helium. Based on our measurements of the relative light yields of liquid and solid neon to liquid helium whose absolute light yield has previously been determined, we find that an alpha source in liquid neon produces up to 5900 photons per MeV while a beta source produces up to 7400 photons per MeV. In solid neon, we find that an alpha particle produces up to 9300 photons per MeV while a beta particle produces up to 17,000 photons per MeV. We observe a significant dependence of the ...

  20. Beta delayed emission of a proton by a one-neutron halo nucleus

    OpenAIRE

    Baye, D.; TURSUNOV, E. M.

    2010-01-01

    Some one-neutron halo nuclei can emit a proton in a beta decay of the halo neutron. The branching ratio towards this rare decay mode is calculated within a two-body potential model of the initial core+neutron bound state and final core+proton scattering states. The decay probability per second is evaluated for the $^{11}$Be, $^{19}$C and $^{31}$Ne one-neutron halo nuclei. It is very sensitive to the neutron separation energy.

  1. Beta decay and delayed proton emission of a new nuclide 59Zn

    International Nuclear Information System (INIS)

    The β+-decay of a new nuclide 59Zn has been identified by β-delayed proton and γ-ray emission. Two γ-rays and 15 proton groups have been associated with the decay of 59Zn. The total proton branching ratio was measured to be (2.3 +- 0.8) x 10-4. A half-life of 210 +- 20 ms was measured for 59Zn. The superallowed β-branch to its mirror, the Jsup(π)=3/2- ground state of 59Cu, was shown to be (93 +- 3)%. Absolute log ft values for β-transitions associated with the observed delayed proton groups were calculated and an experimental β-transition strength function was obtained. (author)

  2. Beta-delayed proton emission in neutron-deficient lanthanide isotopes

    International Nuclear Information System (INIS)

    Forty-two β-delayed proton precursors with 56≤Z≤71 and 63≤N≤83 were produced in heavy-ion reactions at the Lawrence Berkeley Laboratory SuperHILAC and their radioactive decay properties studied at the on-line mass separation facility OASIS. Twenty-five isotopes and eight delayed proton branches were identified for the first time. Delayed proton energy spectra and proton coincident γ-ray and x-ray spectra were measured for all precursors. In a few cases, proton branching ratios were also determined. The precursor mass numbers were determined by the separator, while the proton coincident x-ray energies provided unambiguous Z identifications. The proton coincident γ-ray intensities were used to extract final state branching ratios. Proton emission from ground and isomeric states was observed in many cases. The majority of the delayed proton spectra exhibited the smooth bell-shaped distribution expected for heavy mass precursors. The experimental results were compared to statistical model calculations using standard parameter sets. Calculations using Nilsson model/RPA β-strength functions were found to reproduce the spectral shapes and branching ratios better than calculations using either constant or gross theory β-strength functions. Precursor half-life predictions from the Nilsson model/RPA β-strength functions were also in better agreement with the measured half-lives than were gross theory predictions. The ratios of positron coincident proton intensities to total proton intensities were used to determine Q/sub EC/-B/sub p/ values for several precursors near N=82. The statistical model calculations were not able to reproduce the experimental results for N=81 precursors. 154 refs., 82 figs., 19 tabs

  3. On particle transport in toroidal plasmas at low beta values

    International Nuclear Information System (INIS)

    The plasma-neutral gas balance is considered for the boundary layer of a magnetically confined plasma being near the density (Murakami) limit. It is found that, due to the high rate of charge separation by the guiding centre drifts in an inhomogeneous toroidal magnetic field, Pfirsch-Schlueter particle diffusion can prevail, even in presence of magnetic disturbances which perturb the magnetic surfaces and strongly enhance the electron heat conductivity. In the boundary layer the Nernst and Ware effects become negligible in a first approximation. The characteristic plasma pressure and density gradients in this layer are independent of the plasma diffusion rate, whereas the ratio between the average plasma density and the neutral density at a surrounding wall (limiter) depends on the same rate. The deduced plasma density and pressure gradients and the plasma-neutral density ratio are of the same order as those obtained from tokamak experients. Finally, the heat losses from plasma-neutral gas interaction can in some cases become comparable to the ohmic heating power, thereby affecting the energy containment time. (Author)

  4. A Nonlinear Framework of Delayed Particle Smoothing Method for Vehicle Localization under Non-Gaussian Environment

    Science.gov (United States)

    Xiao, Zhu; Havyarimana, Vincent; Li, Tong; Wang, Dong

    2016-01-01

    In this paper, a novel nonlinear framework of smoothing method, non-Gaussian delayed particle smoother (nGDPS), is proposed, which enables vehicle state estimation (VSE) with high accuracy taking into account the non-Gaussianity of the measurement and process noises. Within the proposed method, the multivariate Student’s t-distribution is adopted in order to compute the probability distribution function (PDF) related to the process and measurement noises, which are assumed to be non-Gaussian distributed. A computation approach based on Ensemble Kalman Filter (EnKF) is designed to cope with the mean and the covariance matrix of the proposal non-Gaussian distribution. A delayed Gibbs sampling algorithm, which incorporates smoothing of the sampled trajectories over a fixed-delay, is proposed to deal with the sample degeneracy of particles. The performance is investigated based on the real-world data, which is collected by low-cost on-board vehicle sensors. The comparison study based on the real-world experiments and the statistical analysis demonstrates that the proposed nGDPS has significant improvement on the vehicle state accuracy and outperforms the existing filtering and smoothing methods. PMID:27187405

  5. A Nonlinear Framework of Delayed Particle Smoothing Method for Vehicle Localization under Non-Gaussian Environment.

    Science.gov (United States)

    Xiao, Zhu; Havyarimana, Vincent; Li, Tong; Wang, Dong

    2016-01-01

    In this paper, a novel nonlinear framework of smoothing method, non-Gaussian delayed particle smoother (nGDPS), is proposed, which enables vehicle state estimation (VSE) with high accuracy taking into account the non-Gaussianity of the measurement and process noises. Within the proposed method, the multivariate Student's t-distribution is adopted in order to compute the probability distribution function (PDF) related to the process and measurement noises, which are assumed to be non-Gaussian distributed. A computation approach based on Ensemble Kalman Filter (EnKF) is designed to cope with the mean and the covariance matrix of the proposal non-Gaussian distribution. A delayed Gibbs sampling algorithm, which incorporates smoothing of the sampled trajectories over a fixed-delay, is proposed to deal with the sample degeneracy of particles. The performance is investigated based on the real-world data, which is collected by low-cost on-board vehicle sensors. The comparison study based on the real-world experiments and the statistical analysis demonstrates that the proposed nGDPS has significant improvement on the vehicle state accuracy and outperforms the existing filtering and smoothing methods. PMID:27187405

  6. A Nonlinear Framework of Delayed Particle Smoothing Method for Vehicle Localization under Non-Gaussian Environment

    Directory of Open Access Journals (Sweden)

    Zhu Xiao

    2016-05-01

    Full Text Available In this paper, a novel nonlinear framework of smoothing method, non-Gaussian delayed particle smoother (nGDPS, is proposed, which enables vehicle state estimation (VSE with high accuracy taking into account the non-Gaussianity of the measurement and process noises. Within the proposed method, the multivariate Student’s t-distribution is adopted in order to compute the probability distribution function (PDF related to the process and measurement noises, which are assumed to be non-Gaussian distributed. A computation approach based on Ensemble Kalman Filter (EnKF is designed to cope with the mean and the covariance matrix of the proposal non-Gaussian distribution. A delayed Gibbs sampling algorithm, which incorporates smoothing of the sampled trajectories over a fixed-delay, is proposed to deal with the sample degeneracy of particles. The performance is investigated based on the real-world data, which is collected by low-cost on-board vehicle sensors. The comparison study based on the real-world experiments and the statistical analysis demonstrates that the proposed nGDPS has significant improvement on the vehicle state accuracy and outperforms the existing filtering and smoothing methods.

  7. The relativistic solar particle event of 2005 January 20: origin of delayed particle acceleration

    OpenAIRE

    Klein, K.-L.; Masson, S.; Bouratzis, C.; Grechnev, V.; Hillaris, A.; Preka-Papadema, P.

    2014-01-01

    The highest energies of solar energetic nucleons detected in space or through gamma-ray emission in the solar atmosphere are in the GeV range. Where and how the particles are accelerated is still controversial. We search for observational information on the location and nature of the acceleration region(s) by comparing the timing of relativistic protons detected on Earth and radiative signatures in the solar atmosphere during the particularly well-observed 2005 Jan. 20 event. This investigati...

  8. Effects of dark energy and flat rotation curve on the gravitational time delay of particle with non-zero mass

    OpenAIRE

    Sarkar, Tamal; Ghosh, Shubhrangshu; Bhadra, Arunava

    2016-01-01

    The effects of several dark energy models on gravitational time delay of particles with non-zero mass are investigated and analytical expressions for the same are obtained at the first order accuracy. Also the expression for gravitational time delay under the influence of conformal gravity potential that well describes the flat rotation curve of spiral galaxies is derived. The findings suggest that i) the conformal gravity description of dark matter reduces the net time delay in contrast to t...

  9. Particle Acceleration during Magnetic Reconnection in a Low-beta Pair Plasma

    CERN Document Server

    Guo, Fan; Daughton, William; Li, Xiaocan; Liu, Yi-Hsin

    2016-01-01

    Plasma energization through magnetic reconnection in the magnetically-dominated regime featured by low plasma beta ($\\beta = 8 \\pi nkT_0/B^2 \\ll 1$) and/or high magnetization ($\\sigma = B^2/(4 \\pi nmc^2) \\gg 1$) is important in a series of astrophysical systems such as solar flares, pulsar wind nebula, and relativistic jets from black holes, etc. In this paper, we review the recent progress on kinetic simulations of this process and further discuss plasma dynamics and particle acceleration in a low-$\\beta$ reconnection layer that consists of electron-positron pairs. We also examine the effect of different initial thermal temperatures on the resulting particle energy spectra. While earlier papers have concluded that the spectral index is smaller for higher $\\sigma$, our simulations show that the spectral index approaches $p=1$ for sufficiently low plasma $\\beta$, even if $\\sigma \\sim 1$. Since this predicted spectral index in the idealized limit is harder than most observations, it is important to consider eff...

  10. Computational methods for analyzing the transmission characteristics of a beta particle magnetic analysis system

    Science.gov (United States)

    Singh, J. J.

    1979-01-01

    Computational methods were developed to study the trajectories of beta particles (positrons) through a magnetic analysis system as a function of the spatial distribution of the radionuclides in the beta source, size and shape of the source collimator, and the strength of the analyzer magnetic field. On the basis of these methods, the particle flux, their energy spectrum, and source-to-target transit times have been calculated for Na-22 positrons as a function of the analyzer magnetic field and the size and location of the target. These data are in studies requiring parallel beams of positrons of uniform energy such as measurement of the moisture distribution in composite materials. Computer programs for obtaining various trajectories are included.

  11. Nonlinear dynamics of beta induced Alfv\\'en eigenmode driven by energetic particles

    CERN Document Server

    Wang, X; Chen, L; Fogaccia, G; Di Troia, C; Vlad, G; Zonca, F

    2012-01-01

    Nonlinear saturation of beta induced Alfv\\'en eigenmode, driven by slowing down energetic particles via transit resonance, is investigated by the nonlinear hybrid magnetohyrodynamic gyro-kinetic code (XHMGC). Saturation is characterized by frequency chirping and symmetry breaking between co- and counter-passing particles, which can be understood as the the evidence of resonance-detuning. The scaling of the saturation amplitude with the growth rate is also demonstrated to be consistent with radial resonance detuning due to the radial non-uniformity and mode structure.

  12. Nonlinear dynamics of beta-induced Alfvén eigenmode driven by energetic particles.

    Science.gov (United States)

    Wang, X; Briguglio, S; Chen, L; Di Troia, C; Fogaccia, G; Vlad, G; Zonca, F

    2012-10-01

    Nonlinear saturation of a beta-induced Alfvén eigenmode, driven by slowing down energetic particles via transit resonance, is investigated by the nonlinear hybrid magnetohyrodynamic gyrokinetic code. Saturation is characterized by frequency chirping and symmetry breaking between co- and counter-passing particles, which can be understood as the evidence of resonance detuning. The scaling of the saturation amplitude with the growth rate is also demonstrated to be consistent with radial resonance detuning due to the radial nonuniformity and mode structure. PMID:23214643

  13. The relativistic solar particle event of 2005 January 20: prompt and delayed particle acceleration

    CERN Document Server

    Klein, K -L; Bouratzis, C; Grechnev, V; Hillaris, A; Preka-Papadema, P

    2014-01-01

    The highest energies of solar energetic nucleons detected in space or through gamma-ray emission in the solar atmosphere are in the GeV range. Where and how the particles are accelerated is still controversial. We search for observational evidence on the acceleration region(s) by comparing the timing of relativistic protons detected at Earth and radiative signatures in the solar atmosphere. To this end a detailed comparison is undertaken of the double-peaked time profile of relativistic protons, derived from the worldwide network of neutron monitors during the large particle event of 2005 January 20, with UV imaging and radio petrography over a broad frequency band from the low corona to interplanetary space. We show that both relativistic proton releases to interplanetary space were accompanied by distinct episodes of energy release and electron acceleration in the corona traced by the radio emission and by brightenings of UV kernels in the low solar atmosphere. The timing of electromagnetic emissions and re...

  14. AstroBox2 - Detector for low-energy β-delayed particle detection

    Science.gov (United States)

    Saastamoinen, A.; Pollacco, E.; Roeder, B. T.; Spiridon, A.; Daq, M.; Trache, L.; Pascovici, G.; De Oliveira, R.; Rodrigues, M. R. D.; Tribble, R. E.

    2016-06-01

    Efficient suppression of β-background is essential for studies of low-energy β-delayed charged particle decays of astrophysical interest. A promising method for such studies has been a micro pattern gas amplifier detector where the sample is implanted into the gas volume and the decays that follow are observed with high gain and signal to noise ratio. An upgraded version of the original AstroBox detector has been built and commissioned at Texas A&M University. Here a description of the new AstroBox2 detector is given, selected results from the commissioning tests are presented, and future perspectives discussed.

  15. An application of Brookhaven National Laboratory's hot particle methodology for determining the most effective beta particle energy in causing skin ulcers

    International Nuclear Information System (INIS)

    The purpose of this project was to compare the effectiveness of hot particles with different energy betas in producing ulcers on skin. The sources were man-made hot particles similar in size and activity to those found in the commercial nuclear power industry. Four different particle types were used. These were thulium (Tm-170) with a 0.97 MeV maximum energy beta, ytterbium (Yb-175) with a maximum beta energy of 0.47 MeV, scandium (Sc-46) with a 0.36 MeV beta, which was used as a surrogate for cobalt-60 (0.31 MeV beta) and uranium (in the carbide form) with an average maximum beta energy of about 2.5 MeV. Since higher energy beta particles penetrate further in skin, they will affect a higher number and different populations of target cells. The experiments were designed as threshold studies such that the dose needed to produce ulcers ten percent of the time (ED 10%) for each particle type could be compared against each other

  16. In vivo biotinylation of recombinant beta-glucosidase enables simultaneous purification and immobilization on streptavidin coated magnetic particles

    DEFF Research Database (Denmark)

    Alftrén, Johan; Ottow, Kim Ekelund; Hobley, Timothy John

    2013-01-01

    Beta-glucosidase from Bacillus licheniformis was in vivo biotinylated in Escherichia coli and subsequently immobilized directly from cell lysate on streptavidin coated magnetic particles. In vivo biotinylation was mediated by fusing the Biotin Acceptor Peptide to the C-terminal of beta-glucosidas...

  17. Effects of dark energy and flat rotation curve on the gravitational time delay of particle with non-zero mass

    CERN Document Server

    Sarkar, Tamal; Bhadra, Arunava

    2016-01-01

    The effects of several dark energy models on gravitational time delay of particles with non-zero mass are investigated and analytical expressions for the same are obtained at the first order accuracy. Also the expression for gravitational time delay under the influence of conformal gravity potential that well describes the flat rotation curve of spiral galaxies is derived. The findings suggest that i) the conformal gravity description of dark matter reduces the net time delay in contrast to the effect of normal dark matter and therefore in principle the models can be discriminated using gravitational time delay observations and ii)the effect of dark energy/flat rotation curve may be revealed from high precision measurements of gravitational time delay of particles involving megaparsec and beyond distance-scale.

  18. Beta decay of 31Ar

    International Nuclear Information System (INIS)

    A complete study of 31Ar beta decay has been made by high-resolution charged-particle and gamma-ray spectroscopy. Beta-delayed radiation was detected by an array of three charged-particle detectors and a large-volume germanium detector. Fifteen new energy levels were discovered in 31Cl. The beta-strength distribution, measured to 14.5 MeV, is compared with a shell-model calculation in the full sd space. The quenching of the Gamow-Teller strength and the isospin impurity of the IAS in 31Cl are discussed. (orig.)

  19. Is delayed genomic instability specifically induced by high-LET particles?

    Science.gov (United States)

    Testard, Isabelle; Sabatier, Laure

    1998-12-01

    Ionizing radiation can induce a large variety of damages in the DNA. The processing or repair of this damage occurs in the first minutes up to several hours after irradiation. Afterwhile the remaining lesions are fixed in an irreparable state. However, in recent years, data have accumulated to suggest that genomic instability can manifest in the progeny of irradiated cells leading to accumulation of damage through cell generations. Different biological endpoints were described: delayed cell death, delayed mutations, de novo chromosomal instability. The question regarding the ability of sparsely ionizing X-or γ-rays to induce such phenomenon is still unclear for normal cells. In most of the reports, high linear energy transfer (LET) particles are able to induce genomic instability but not low-LET particles. The mechanisms underlying this phenomenon are still unknown. In human fibroblasts irradiated by heavy ions in a large range of LETs, we showed that the chromosomal instability is characterized by telomeric associations (TAS) involving specific chromosomes. The same instability is observed during the senescence process and during the first passages after viral transfection. The specific chromosomal instability that we observed after irradiation would not be a direct consequence of irradiation but would be a natural phenomenon occurring after many cell divisions. The effect of the irradiation would lie on the bypass of the senescence process that would permit cells with end to end fusions to survive and be transmitted through cell generations, accumulating chromosome rearrangements and chromosome imbalances. Research on molecular mechanisms of chromosomal instability is focused on the role of telomeres in end to end fusions. Such observations could contribute to understand why chromosomal instability is not a dose dependant phenomenon. Why high-LET particles would be so potent in inducing delayed instability? The answer might lie in the study of primary effects of

  20. Particle-vibration coupling effect on the $\\beta$-decay of magic nuclei

    CERN Document Server

    Niu, Yifei; Colo, Gianluca; Vigezzi, Enrico

    2015-01-01

    Nuclear $\\beta$-decay in magic nuclei is investigated, taking into account the coupling between particle and collective vibrations,on top of self-consistent random phase approximation calculations based on Skyrme density functionals. The low-lying Gamow-Teller strength is shifted downwards and at times becomes fragmented; as a consequence, the $\\beta$-decay half-lives are reduced due to the increase of the phase space available for the decay. In some cases, this leads to a very good agreement between theoretical and experimental lifetimes: this happens, in particular, in the case of the Skyrme force SkM*, that can also reproduce the line shape of the high energy Gamow-Teller resonance as it was previously shown.

  1. Determination of uranium in urine samples of fuel element fabrication workers by beta-delayed neutron counting

    Science.gov (United States)

    Gabelmann, H.; Lerch, M.; Kratz, K.-L.; Rudolph, W.

    1984-06-01

    Within the health physics examination of fuel element fabrication workers, the control of uranium incorporation is of importance. This is commonly performed by the determination of the alpha activity concentration of uranium excreted in the urine. However, since the chemical separation procedure and the preparation of alpha-counting samples are complicated and time-consuming, this method may imply restrictions on the routine control of large numbers of persons. Therefore, we have investigated the applicability of measuring the beta-delayed neutrons from thermal neutron induced fission of the 235U in the urine samples. The uranium was separated by coprecipitation with Fe(OH) 3 from the urine samples and irradiated in a rabbit system of the Mainz TRIGA reactor. The neutrons were counted with a 3He long counter. The detection limit of 0.3 to 0.9 pCi 1 -1 is comparable to that of alpha spectrometry, but the time required for one sample, from preparation to data evaluation is less than 25 min.

  2. Monte Carlo Models for the Production of beta-delayed Gamma Rays Following Fission of Special Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    Pruet, J; Prussin, S; Descalle, M; Hall, J

    2004-02-03

    A Monte Carlo method for the estimation of {beta}-delayed {gamma}-ray spectra following fission is described that can accommodate an arbitrary time-dependent fission rate and photon collection history. The method invokes direct sampling of the independent fission yield distributions of the fissioning system, the branching ratios for decay of individual fission products and the spectral distributions for photon emission for each decay mode. Though computationally intensive, the method can provide a detailed estimate of the spectrum that would be recorded by an arbitrary spectrometer, and can prove useful in assessing the quality of evaluated data libraries, for identifying gaps in these libraries, etc. The method is illustrated by a first comparison of calculated and experimental spectra from decay of short-lived fission products following the reactions {sup 235}U(n{sub th}, f) and {sup 239}Pu(n{sub th}, f). For general purpose transport calculations, where detailed consideration of the large number of individual {gamma}-ray transitions in a spectrum may be unnecessary, it is shown that an accurate and simple parameterization of a {gamma}-ray source function can be obtained. These parametrizations should provide high-quality average spectral distributions that should prove useful in calculations describing photons escaping from thick attenuating media.

  3. Absorption and scattering of 90Sr/90Y beta particles transmitted through aluminium and plastic filters

    International Nuclear Information System (INIS)

    Absorption and scattering of 90Sr/90Y beta particles transmitted through aluminium and plastic filters have been studied. From measurements of the ionisation current by the extrapolation chamber, it was shown that a build-up in absorbed dose rate occurred over the first 0.1 mm of aluminium thickness before attenuation started to dominate. This build-up thickness corresponded to a δ particle energy of 150 keV. The attenuation at large thicknesses followed an exponential function which predicted a half-value thickness of ∼ 112mg.cm-2 and a range (99% attenuation) of ∼1000 mg.cm-2. Angular distributions of the absorbed dose rate for 90Sr/90Y beta particles transmitted through aluminium and plastic filters have also been measured. These distributions followed the multiple scattering Gaussian curves for small projected angles and the single scattering tails for large projected angles. The mean square angle of the Gaussian distribution was approximately a linear function of the filter thickness. The peak height, however, dropped rapidly with increasing filter thickness at small thicknesses but slowly at large thicknesses. Both the mean square angle and the peak height were slightly dependent on the filter material. (Author)

  4. Cerenkov radiation imaging as a method for quantitative measurements of beta particles in a microfluidic chip

    International Nuclear Information System (INIS)

    It has been observed that microfluidic chips used for synthesizing 18F-labeled compounds demonstrate visible light emission without nearby scintillators or fluorescent materials. The origin of the light was investigated and found to be consistent with the emission characteristics from Cerenkov radiation. Since 18F decays through the emission of high-energy positrons, the energy threshold for beta particles, i.e. electrons or positrons, to generate Cerenkov radiation was calculated for water and polydimethylsiloxane (PDMS), the most commonly used polymer-based material for microfluidic chips. Beta particles emitted from 18F have a continuous energy spectrum, with a maximum energy that exceeds this energy threshold for both water and PDMS. In addition, the spectral characteristics of the emitted light from 18F in distilled water were also measured, yielding a broad distribution from 300 nm to 700 nm, with higher intensity at shorter wavelengths. A photograph of the 18F solution showed a bluish-white light emitted from the solution, further suggesting Cerenkov radiation. In this study, the feasibility of using this Cerenkov light emission as a method for quantitative measurements of the radioactivity within the microfluidic chip in situ was evaluated. A detector previously developed for imaging microfluidic platforms was used. The detector consisted of a charge-coupled device (CCD) optically coupled to a lens. The system spatial resolution, minimum detectable activity and dynamic range were evaluated. In addition, the calibration of a Cerenkov signal versus activity concentration in the microfluidic chip was determined. This novel method of Cerenkov radiation measurements will provide researchers with a simple yet robust quantitative imaging tool for microfluidic applications utilizing beta particles.

  5. Thermoluminescent response of CaSO4: Dy + PTFE to beta particles

    International Nuclear Information System (INIS)

    In this work the results of studying the thermoluminescent properties of CaSO4: Dy + PTFE are presented when it is irradiated with beta particles. The conclusion was the obtention of the Tl response curve in function of dose is that to desexcite the dosemeters at temperature 300 C during 30 minutes and after that were irradiated at different times in groups and to do the reading of dosemeter, it can be observed that a greater irradiation time major is the Tl response and this depends of the material has been used. (Author)

  6. Calibration of beta-particle ophthalmic applicators at the National Bureau of Standards

    International Nuclear Information System (INIS)

    The method used at the National Bureau of Standards for the calibration of strontium-90 + yttrium-90 beta-particle ophthalmic applicators in terms of absorbed dose to water, is described. The method involves measurement of ionization density at the applicator surface with an extrapolation chamber, correction for the difference in backscatter between the collection electrode and water, and application of the Bragg-Gray equation. The calibration obtained is an average over the active surface of the applicator. The overall uncertainty of the surface calibration is about + or - 15 percent

  7. Magneto-HydroDynamic activity and Energetic Particles - Application to Beta Alfven Eigenmodes

    CERN Document Server

    Nguyen, Christine

    2009-01-01

    The goal of magnetic fusion research is to extract the power released by fusion reactions and carried by the product of these reactions, liberated at energies of the order of a few MeV. The feasibility of fusion energy production relies on our ability to confine these energetic particles, while keeping the thermonuclear plasma in safe operating conditions. For that purpose, it is necessary to understand and find ways to control the interaction between energetic particles and the thermonuclear plasma. Reaching these two goals is the general motivation for the work conducted during the PhD. More specifically, our focus is on one type of instability, the Beta Alfven Eigenmode (BAE), which can be driven by energetic particles and impact on the confinement of both energetic and thermal particles. In this work, we study the characteristics of BAEs analytically and derive its dispersion relation and structure. Next, we analyze the linear stability of the mode in the presence of energetic particles. First, a purely l...

  8. Heat shock protein-90-beta facilitates enterovirus 71 viral particles assembly

    International Nuclear Information System (INIS)

    Molecular chaperones are reported to be crucial for virus propagation, but are not yet addressed in Human Enterovirus 71 (EV71). Here we describe the specific association of heat shock protein-90-beta (Hsp90β), but not alpha form (Hsp90α), with EV71 viral particles by the co-purification with virions using sucrose density gradient ultracentrifugation, and by the colocalization with viral particles, as assessed by immunogold electron microscopy. The reduction of the Hsp90β protein using RNA interference decreased the correct assembly of viral particles, without affecting EV71 replication levels. Tracking ectopically expressed Hsp90β protein associated with EV71 virions revealed that Hsp90β protein was transmitted to new host cells through its direct association with infectious viral particles. Our findings suggest a new antiviral strategy in which extracellular Hsp90β protein is targeted to decrease the infectivity of EV71 and other enteroviruses, without affecting the broader functions of this constitutively expressed molecular chaperone. - Highlights: • Hsp90β is associated with EV71 virion and is secreted with the release virus. • Hsp90β effects on the correct assembly of viral particles. • Viral titer of cultured medium was reduced in the presence of geldanamycin. • Viral titer was also reduced when Hsp90β was suppressed by siRNA treatment. • The extracellular Hsp90β was also observed in other RNA viruses-infected cells

  9. Heat shock protein-90-beta facilitates enterovirus 71 viral particles assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Robert Y.L., E-mail: yuwang@mail.cgu.edu.tw [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Kuo, Rei-Lin [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Medical Biotechnology and Laboratory Science and Graduate Program of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Ma, Wei-Chieh [Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Huang, Hsing-I [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Medical Biotechnology and Laboratory Science and Graduate Program of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Yu, Jau-Song [Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Molecular Medicine Research Center, Chang Gung University, Tao-Yuan 333, Taiwan (China); Yen, Sih-Min [Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Huang, Chi-Ruei [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Shih, Shin-Ru [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Medical Biotechnology and Laboratory Science and Graduate Program of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China)

    2013-09-01

    Molecular chaperones are reported to be crucial for virus propagation, but are not yet addressed in Human Enterovirus 71 (EV71). Here we describe the specific association of heat shock protein-90-beta (Hsp90β), but not alpha form (Hsp90α), with EV71 viral particles by the co-purification with virions using sucrose density gradient ultracentrifugation, and by the colocalization with viral particles, as assessed by immunogold electron microscopy. The reduction of the Hsp90β protein using RNA interference decreased the correct assembly of viral particles, without affecting EV71 replication levels. Tracking ectopically expressed Hsp90β protein associated with EV71 virions revealed that Hsp90β protein was transmitted to new host cells through its direct association with infectious viral particles. Our findings suggest a new antiviral strategy in which extracellular Hsp90β protein is targeted to decrease the infectivity of EV71 and other enteroviruses, without affecting the broader functions of this constitutively expressed molecular chaperone. - Highlights: • Hsp90β is associated with EV71 virion and is secreted with the release virus. • Hsp90β effects on the correct assembly of viral particles. • Viral titer of cultured medium was reduced in the presence of geldanamycin. • Viral titer was also reduced when Hsp90β was suppressed by siRNA treatment. • The extracellular Hsp90β was also observed in other RNA viruses-infected cells.

  10. Nuclear Double Beta Decay, Fundamental Particle Physics, Hot Dark Matter, And Dark Energy

    CERN Document Server

    Klapdor-Kleingrothaus, Hans Volker

    2010-01-01

    Nuclear double beta decay, an extremely rare radioactive decay process, is - in one of its variants - one of the most exciting means of research into particle physics beyond the standard model. The large progress in sensitivity of experiments searching for neutrinoless double beta decay in the last two decades - based largely on the use of large amounts of enriched source material in "active source experiments" - has lead to the observation of the occurrence of this process in nature (on a 6.4 sigma level), with the largest half-life ever observed for a nuclear decay process (2.2 x 10^{25} y). This has fundamental consequences for particle physics - violation of lepton number, Majorana nature of the neutrino. These results are independent of any information on nuclear matrix elements (NME)*. It further leads to sharp restrictions for SUSY theories, sneutrino mass, right-handed W-boson mass, superheavy neutrino masses, compositeness, leptoquarks, violation of Lorentz invariance and equivalence principle in the...

  11. A system for intercomparing standard solutions of beta-particle emitting radionuclides

    International Nuclear Information System (INIS)

    A system for intercomparing standard solutions of pure beta-particle emitting radionuclides is described. The CIEMAT/NIST technique of beta-particle efficiency tracing is based on establishing a parameter in a simple calculational model, using a 3H standard with comparable quenching. To produce a 3H-in-scintillator standard which is reasonably stable over the period of the measurements, we first standardized 3H-hexadecane solution by comparison with 3H-water standardized by gas counting. In the second phase of the work, the 3H-hexadecane solution was used to standardize 14C-hexadecane and 99Tc-tricaprylamine (TCA). Measurements were made under similar geometrical and quenching conditions for each radionuclide with a commercial scintillator and a conventional liquid-scintillation counter with two phototubes operating in coincidence. The technique was then tested at different sites in the area using a set of flame-sealed vials and state-of-the-art liquid-scintillation counters. Initial results for the 90Tc-TCA and the 1981 99Tc, Standard Material (SRM) 4288 show an agreement to within 0.30%. (orig.)

  12. Physical consequences of the alpha/beta rule which accurately calculates particle masses

    International Nuclear Information System (INIS)

    Using the fine structure constant α (=1/137.036), the proton vs. electron mass ratio β (= 1836.2) and the integers m and n, the α/β rule: mparticle = α-n x β m x 27.2 eV/c2 allows almost exact calculation of particle masses. (K.O.Greulich, DPG Spring meeting 2014, Mainz, T99.4) With n=2, m=0 the electron mass becomes 510.79 keV/c2 (experimental 511 keV/c2) With n=2, m=1 the proton mass is 937.9 MeV/c2 (literature 938.3 MeV/c2). For n=3 and m=1 a particle with 128.6 GeV/c2 close to the reported Higgs mass, is expected. For n=14 and m=-1 the Planck mass results. The calculated masses for gauge bosons and for quarks have similar accuracy. All masses fit into the same scheme (the alpha/beta rule), indicating that non of these particle masses play an extraordinary role. Particularly, the Higgs Boson, often termed the *God particle* plays in this sense no extraordinary role. In addition, particle masses are intimately correlated with the fine structure constant α. If particle masses have been constant over all times, α must have been constant over these times. In addition, the ionization energy of the hydrogen atom (13.6 eV) needs to have been constant if particle masses have been unchanged or vice versa. In conclusion, the α/β rule needs to be taken into account when cosmological models are developed.

  13. Trend of Gross Beta Radioactivity in Air Particles and Rainwater of around the Domestic Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Jungmin; Shin, Daeyewn; Kim, Soongpyung; Ju, Sundong [Chosun Univ., Gwangju (Korea, Republic of); OH, Youngsoo; Kim, Byunggyu; Kim, Sunsik [Hanbit Nuclear Power Site, Seoul (Korea, Republic of)

    2014-05-15

    Investigating items can be distinguished into two parts, regional radiation and concentrations of environmental radioactivity, and in environmental radioactivity, to access the internal exposure dose, gross beta-radioactivity of particles in air and rainwater specimen are being tested. Gross beta-radioactivity quickly shows whether radiation is unusual or no since most of nuclide released in radioactive emergency while operating an atomic energy facility emits beta rays, and the method used to test it is simple. Looking at the years of analyzed results of particles in air and rainwater around the facility for gross beta-radioactivity, they have a constant trend. The cause of the trend was investigated with a doubt that something else rather than operation of a nuclear power plant might have caused this trend. Due to high gross beta radioactivity concentration in winter, sometimes, radioactivity concentration five times higher than reported last five years average gross beta radioactivity concentration is detected. Looking at the contents investigated above, we can see nuclear power plants have correlation with surrounding gross beta radioactivity concentration. Precipitation has negative correlation, and the weight of air particles and concentration of component element have positive correlation. Our country is influenced by northwest wind in winter. China which is located northwest, has heavy air pollution and smog due to industrialization and there was a report saying it is affecting Korea. Therefore, not because of management of power plants but because of change in season, it can be misunderstood that operating power plants is causing the increased gross beta radioactivity concentration. Based on this investigation, more research to find various causes of gross beta radioactivity concentration in winter is necessary.

  14. Magneto-Hydrodynamic Activity and Energetic Particles - Application to Beta Alfven Eigenmodes

    International Nuclear Information System (INIS)

    The goal of magnetic fusion research is to extract the power released by fusion reactions and carried by the product of these reactions, liberated at energies of the order of a few MeV. The feasibility of fusion energy production relies on our ability to confine these energetic particles, while keeping the thermonuclear plasma in safe operating conditions. For that purpose, it is necessary to understand and find ways to control the interaction between energetic particles and the thermonuclear plasma. Reaching these two goals is the general motivation for this work. More specifically, our focus is on one type of instability, the Beta Alfven Eigenmode (BAE), which can be driven by energetic particles and impact on the confinement of both energetic and thermal particles. In this work, we study the characteristics of BAEs analytically and derive its dispersion relation and structure. Next, we analyze the linear stability of the mode in the presence of energetic particles. First, a purely linear description is used, which makes possible to get an analytical linear criterion for BAE destabilization in the presence of energetic particles. This criterion is compared with experiments conducted in the Tore-Supra tokamak. Secondly, because the linear analysis reveals some features of the BAE stability which are subject to a strong nonlinear modification, the question is raised of the possibility of a sub-critical activity of the mode. We propose a simple scenario which makes possible the existence of meta-stable modes, verified analytically and numerically. Such a scenario is found to be relevant to the physics and scales characterizing BAEs. (author)

  15. Part I: $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with astatine beams; Part II: Delineating the island of deformation in the light gold isotopes by means of laser spectroscopy

    CERN Document Server

    Andreyev, Andrei

    2013-01-01

    Part I: $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with astatine beams; Part II: Delineating the island of deformation in the light gold isotopes by means of laser spectroscopy

  16. Characterization of Delayed-Particle Emission Signatures for Pyroprocessing. Part 1: ABTR Fuel Assembly.

    Energy Technology Data Exchange (ETDEWEB)

    Durkee, Jr., Joe W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-19

    A three-part study is conducted using the MCNP6 Monte Carlo radiation-transport code to calculate delayed-neutron (DN) and delayed-gamma (DG) emission signatures for nondestructive assay (NDA) metal-fuel pyroprocessing. In Part 1, MCNP6 is used to produce irradiation-induced used nuclear fuel (UNF) isotopic inventories for an Argonne National Laboratory (ANL) Advanced Burner Test Reactor (ABTR) preconceptual design fuel assembly (FA) model. The initial fuel inventory consists of uranium mixed with light-water-reactor transuranic (TRU) waste and 10 wt% zirconium (U-LWR-SFTRU-10%Zr). To facilitate understanding, parametric evaluation is done using models for 3% and 5% initial 235U a% enrichments, burnups of 5, 10, 15, 20, 30, …, 120 GWd/MTIHM, and 3-, 5-, 10-, 20-, and 30- year cooling times. Detailed delayed-particle radioisotope source terms for the irradiate FA are created using BAMF-DRT and SOURCES3A. Using simulation tallies, DG activity ratios (DGARs) are developed for 134Cs/137Cs 134Cs/154Eu, and 154Eu/137Cs markers as a function of (1) burnup and (2) actinide mass, including elemental uranium, neptunium, plutonium, americium, and curium. Spectral-integrated DN emission is also tallied. The study reveals a rich assortment of DGAR behavior as a function of DGAR type, enrichment, burnup, and cooling time. Similarly, DN emission plots show variation as a function of burnup and of actinide mass. Sensitivity of DGAR and DN signatures to initial 235U enrichment, burnup, and cooling time is evident. Comparisons of the ABTR radiation signatures and radiation signatures previously reported for a generic Westinghouse oxide-fuel assembly indicate that there are pronounced differences in the ABTR and Westinghouse oxide-fuel DN and DG signatures. These differences are largely attributable to the initial TRU inventory in the ABTR fuel. The actinide and nonactinide inventories for the

  17. Thermoluminescence of europium-doped zinc oxide exposed to beta particle irradiation

    International Nuclear Information System (INIS)

    Full text: Zn O is a promising material for a range of optoelectronics applications, due to its direct wide band gap (Eg ∼3.3 eV at 300 K) and large exciton binding energy (60 MeV). Its applications include UV light emitters, varistors, surface acoustic wave devices, piezoelectric transducers, and chemical and gas sensing. Rare-earth activation of phosphors has long been seen as an effective process since coupling energy into the rare-earth-ion site, either by ionization, charge exchange or a resonance energy process, results in light production. It is reported that Europium modifies the response thermoluminescence (Tl) for pure zinc oxide, when is irradiated with X-ray, created a peak at 365 degrees C. In this work, Zn O:Eu phosphors were synthesized by a chemical method. Some samples were exposed to beta particle irradiation for doses ranging from 1 up to 100 Gy. Tl response as a function of dose is linear throughout the studied dose range. The glow curve exhibits three maxima, centered at 176, 279 and 340 degrees C. The reusability studies obtained after ten repeated cycles of annealing irradiation readout for the Zn O:Eu shows that the variation in the Tl response is ten percent and tends to stabilization. The results indicate that these new Zn O:Eu phosphors are promising detectors and dosimeters for beta radiation. The structural and morphological characterization was carried out by X-ray diffraction and scanning electron microscopy, respectively. (Author)

  18. Assessment of gamma, beta and alpha-particle-emitting nuclides in marine samples

    International Nuclear Information System (INIS)

    Depending on the physical properties of radionuclides different systems must be used for their measurement. Most convenient is if gamma spectrometry can be used by germanium, Silicon or Scintillation detectors (eg. NaI). If, however, the main emission consists of beta or alpha particles or low-energy photons as is the case for radionuclides decaying by electron capture, radiochemical separation and specific source preparations must be undertaken. In such cases also the radiochemical yield must be determined. The radiochemical part mainly follows the lines presented by prof. T. Jaakkola, Department of Radiochemistry, Helsinki, Finland, at a course in radioecology in Lurid, 1991. For very long-lived radionuclides other methods such as mass spectrometry are superior although often associated with sophisticated expensive instrumentation. (author)

  19. Nuclear energy - Reference beta-particle radiation - Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field

    International Nuclear Information System (INIS)

    ISO 6980 consists of the following parts, under the general title Nuclear energy - Reference beta-particle radiation: Part 1: Method of production; Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field; Part 3: Calibration of area and personal dosimeters and determination of their response as a function of energy and angle of incidence. This part 2 of ISO 6980 specifies methods for the measurement of the directional absorbed-dose rate in a tissue-equivalent slab phantom in the ISO 6980 reference beta-particle radiation fields. The energy range of the beta-particle-emitting isotopes covered by these reference radiations is 0.066 to 3.54 MeV (maximum energy). Radiation energies outside this range are beyond the scope of this standard. While measurements in a reference geometry (depth of 0.07 mm at perpendicular incidence in a tissue-equivalent slab phantom) with a reference class extrapolation chamber are dealt with in detail, the use of other measurement systems and measurements in other geometries are also described, although in less detail. The ambient dose equivalent, H*(10) as used for area monitoring of strongly penetrating radiation, is not an appropriate quantity for any beta radiation, even for that penetrating a 10 mm thick layer of ICRU tissue (i.e. Emax > 2 MeV). If adequate protection is provided at 0.07 mm, only rarely will one be concerned with other depths, for example 3 mm. This document is geared towards organizations wishing to establish reference-class dosimetry capabilities for beta particles, and serves as a guide to the performance of dosimetry with the reference class extrapolation chamber for beta-particle dosimetry in other fields. Guidance is also provided on the statement of measurement uncertainties

  20. Measurement of the rate of wear of dental composite resins by a 90Sr beta particle transmission gauge

    International Nuclear Information System (INIS)

    The wear rate of restorative dental composite resins is an important parameter in the assessment of their in vivo performance. The two more widely used methods of quantifying wear are measuring the dimensional change and measuring the change in the mass of the specimen. The former method is complicated by uneven wear of specimens and presents difficulties with samples of irregular shape, and the latter method involves measurements of changes in mass as small as tens of micrograms with specimens of sizes similar to those encountered clinically. A 90Sr beta particle transmission gauge has been designed and constructed to enable the wear rate of small specimens of dental composite resins to be measured. The 90Sr beta particle transmission gauge enables indirect measurements of changes in mass to be made and overcomes some of the difficulties inherent in the direct measurement of mass and length. Applications of the 90Sr beta particle transmission gauge to the measurement of wear rates are given for restorative dental resins having a range of inorganic filler contents and types. The results show that the 90Sr beta particle transmission gauge is capable of measuring the rate of wear to a degree of precision similar to that of micrometer-derived measurements

  1. Localization and quantitation of tritiated compounds in tissue sections with a gaseous detector of beta particles: Comparison with film autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Tribollet, E.; Dreifuss, J.J.; Charpak, G.; Dominik, W.; Zaganidis, N. (Univ. Medical Centre, Geneva (Switzerland))

    1991-02-15

    Quantitative analysis of tritium polymer standards and of brain sections labeled with tritiated vasopressin was carried out by using a gaseous detector of beta particles designed for this purpose. The gaseous detector showed major advantages compared with film autoradiography: the linearity and the large dynamic range of intensity measurements as well as the short time needed for data acquisition.

  2. Thermoluminescence of europium-doped zinc oxide exposed to beta particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Iriqui R, J. L.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R. [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83000 Hermosillo, Sonora (Mexico); Castano, V. M., E-mail: jorgeiriqui@gimmunison.com [UNAM, Instituto de Fisica, Centro de Fisica Aplicada y Tecnologia Avanzada, Apdo. Postal 1-1010, 76000 Queretaro, Qro. (Mexico)

    2015-10-15

    Full text: Zn O is a promising material for a range of optoelectronics applications, due to its direct wide band gap (E{sub g} ∼3.3 eV at 300 K) and large exciton binding energy (60 MeV). Its applications include UV light emitters, varistors, surface acoustic wave devices, piezoelectric transducers, and chemical and gas sensing. Rare-earth activation of phosphors has long been seen as an effective process since coupling energy into the rare-earth-ion site, either by ionization, charge exchange or a resonance energy process, results in light production. It is reported that Europium modifies the response thermoluminescence (Tl) for pure zinc oxide, when is irradiated with X-ray, created a peak at 365 degrees C. In this work, Zn O:Eu phosphors were synthesized by a chemical method. Some samples were exposed to beta particle irradiation for doses ranging from 1 up to 100 Gy. Tl response as a function of dose is linear throughout the studied dose range. The glow curve exhibits three maxima, centered at 176, 279 and 340 degrees C. The reusability studies obtained after ten repeated cycles of annealing irradiation readout for the Zn O:Eu shows that the variation in the Tl response is ten percent and tends to stabilization. The results indicate that these new Zn O:Eu phosphors are promising detectors and dosimeters for beta radiation. The structural and morphological characterization was carried out by X-ray diffraction and scanning electron microscopy, respectively. (Author)

  3. Evaluation of Beta-Delayed Neutron Emission Probabilities and Half-Lives for Z = 2–28

    Energy Technology Data Exchange (ETDEWEB)

    Birch, M. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Singh, B., E-mail: ndgroup@mcmaster.ca [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Dillmann, I. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Abriola, D. [Department of Physics, TANDAR Laboratory, C.N.E.A., Buenos Aires (Argentina); Johnson, T.D.; McCutchan, E.A.; Sonzogni, A.A. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)

    2015-09-15

    We present an evaluation and compilation of β-delayed neutron probabilities and half-lives for nuclei in the region Z = 2–28 ({sup 8}He–{sup 80}Ni). This article includes the recommended values of these quantities as well as a compiled list of experimental measurements for each nucleus in the region for which β-delayed neutron emission is possible. The literature cut-off for this work is August 15{sup th}, 2015. Some notable cases as well as new standards for β-delayed neutron measurements in this mass region are also discussed.

  4. Evaluation of Beta-Delayed Neutron Emission Probabilities and Half-Lives for Z = 2–28

    International Nuclear Information System (INIS)

    We present an evaluation and compilation of β-delayed neutron probabilities and half-lives for nuclei in the region Z = 2–28 (8He–80Ni). This article includes the recommended values of these quantities as well as a compiled list of experimental measurements for each nucleus in the region for which β-delayed neutron emission is possible. The literature cut-off for this work is August 15th, 2015. Some notable cases as well as new standards for β-delayed neutron measurements in this mass region are also discussed

  5. Modeling early physical and chemical events for DNA damage induced by photons and tritium beta particles

    International Nuclear Information System (INIS)

    A method has been developed to model production of single-strand breaks (SSB) and double-strand breaks (DSB) in Deoxyribo Nucleic Acid (DNA) by ionizing radiations. Modeling is carried out by Monte Carlo means and includes consideration of direct energy depositions in DNA molecules, production of chemical species following water radiolysis, diffusion of chemical species, and their interactions with each other and DNA. Computer-generated electron tracks in liquid water are used to model energy deposition and to derive the initial localization of chemical species. Atomistic representation of the DNA with a first hydration shell is used to derive direct energy depositions in DNA molecules and the resulting consequences, and to derive coordinates of reactive sites for modeling of the chemical stage of radiation damage. Diffusion of chemical species is followed in time, and the reactions of species with each other and DNA are considered to occur in an encounter-controlled manner. Time of diffusion follow-up is restricted to 10-12- 10-9 s, which yields a diffusion length of hydroxyl radicals comparable to that in the cellular environment. DNA SSB are assumed to result from any direct energy depositions in the sugar/phosphate moiety, ionizations in water molecules bound to sugar/phosphate and hydroxyl attacks on deoxyribose. DSB are assumed to result from two SSB on opposite strands separated by 10 or fewer base pairs. Photon radiations in the energy range 70 keV-1 MeV and tritium beta particles are considered. It is shown that for naked DNA in B-form (the configuration thought to be most biologically relevant) the effectiveness of tritium for SSB and DSB production is, within statistical uncertainties, comparable to photon radiation with energies in the range 70 keV-1 MeV, although a tendency for increased DSB production has been observed for 70 keV photons that represent orthovoltage X-rays and for tritium beta particles. It is predicted that hydroxyl radicals react

  6. Modeling early physical and chemical events for DNA damage induced by photons and tritium beta particles

    Energy Technology Data Exchange (ETDEWEB)

    Moiseenko, V. [McMaster Univ., Dept. of Physics and Astronomy, Hamilton, Ontario (Canada); Waker, A.J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Prestwich, W.V. [McMaster Univ., Dept. of Physics and Astronomy, Hamilton, Ontario (Canada)

    1998-02-01

    A method has been developed to model production of single-strand breaks (SSB) and double-strand breaks (DSB) in Deoxyribo Nucleic Acid (DNA) by ionizing radiations. Modeling is carried out by Monte Carlo means and includes consideration of direct energy depositions in DNA molecules, production of chemical species following water radiolysis, diffusion of chemical species, and their interactions with each other and DNA. Computer-generated electron tracks in liquid water are used to model energy deposition and to derive the initial localization of chemical species. Atomistic representation of the DNA with a first hydration shell is used to derive direct energy depositions in DNA molecules and the resulting consequences, and to derive coordinates of reactive sites for modeling of the chemical stage of radiation damage. Diffusion of chemical species is followed in time, and the reactions of species with each other and DNA are considered to occur in an encounter-controlled manner. Time of diffusion follow-up is restricted to 10{sup -12}- 10{sup -9} s, which yields a diffusion length of hydroxyl radicals comparable to that in the cellular environment. DNA SSB are assumed to result from any direct energy depositions in the sugar/phosphate moiety, ionizations in water molecules bound to sugar/phosphate and hydroxyl attacks on deoxyribose. DSB are assumed to result from two SSB on opposite strands separated by 10 or fewer base pairs. Photon radiations in the energy range 70 keV-1 MeV and tritium beta particles are considered. It is shown that for naked DNA in B-form (the configuration thought to be most biologically relevant) the effectiveness of tritium for SSB and DSB production is, within statistical uncertainties, comparable to photon radiation with energies in the range 70 keV-1 MeV, although a tendency for increased DSB production has been observed for 70 keV photons that represent orthovoltage X-rays and for tritium beta particles. It is predicted that hydroxyl

  7. β-delayed γ-proton decay in 56Zn: Analysis of the charged-particle spectrum

    International Nuclear Information System (INIS)

    A study of the β decay of the proton-rich Tz = –2 nucleus 56Zn has been reported in a recent publication. A rare and exotic decay mode, β-delayed γ-proton decay, has been observed there for the first time in the fp shell. Here, we expand on some of the details of the data analysis, focusing on the charged particle spectrum

  8. Half-lives and branchings for {\\beta}-delayed neutron emission for neutron-rich Co-Cu isotopes in the r-process

    CERN Document Server

    Hosmer, P; Aprahamian, A; Arndt, O; Clement, R R C; Estrade, A; Farouqi, K; Kratz, K -L; Liddick, S N; Lisetskiy, A F; Mantica, P F; Möller, P; Mueller, W F; Montes, F; Morton, A C; Ouellette, M; Pellegrini, E; Pereira, J; Pfeiffer, B; Reeder, P; Santi, P; Steiner, M; Stolz, A; Tomlin, B E; Walters, W B; Wöhr, A; 10.1103/PhysRevC.82.025806

    2010-01-01

    The {\\beta} decays of very neutron-rich nuclides in the Co-Zn region were studied experimentally at the National Superconducting Cyclotron Laboratory using the NSCL {\\beta}-counting station in conjunction with the neutron detector NERO. We measured the branchings for {\\beta}-delayed neutron emission (Pn values) for 74Co (18 +/- 15%) and 75-77Ni (10 +/- 2.8%, 14 +/- 3.6%, and 30 +/- 24%, respectively) for the first time, and remeasured the Pn values of 77-79Cu, 79,81Zn, and 82Ga. For 77-79Cu and for 81Zn we obtain significantly larger Pn values compared to previous work. While the new half-lives for the Ni isotopes from this experiment had been reported before, we present here in addition the first half-life measurements of 75Co (30 +/- 11 ms) and 80Cu (170+110 -50 ms). Our results are compared with theoretical predictions, and their impact on various types of models for the astrophysical rapid neutron-capture process (r-process) is explored. We find that with our new data, the classical r-process model is bet...

  9. Thermoluminescence characteristics of LiF:Mg,Cu,P + PTFE irradiated with beta particles

    International Nuclear Information System (INIS)

    Among the various thermoluminescent (TL) phosphors developed in our laboratories, the tissue equivalent, high sensitive and very stable LiF:Mg,Cu,P TL material has turned out to be of special interest to be used in environmental monitoring and medical dosimetry. Dosimetric characteristics of this material, in powder form, have been reported in previous works. In order to have this material in solid form we developed a method to prepare pellets of this phosphor embedded in polytetrafluoroethylene (LiF:Mg,Cu,P + PTFE). This paper presents the results of studying the thermoluminescent response and the kinetics of these LiF:Mg,Cu,P + PTFE pellets when irradiating them with 90Sr/90Y beta particles. The results showed that LiF:Mg,Cu,P + PTFE exhibits a typical glow curve with three peaks at 120, 210 and 285 deg C, respectively, which were separated by the deconvolution method. Applying this method, we obtained that all of them obey a first order kinetics and have an activation energy of 1.35, 1.58 and 2.51 eV respectively. The TL response as a function of dose was linear in the range from 4.35 mGy to 2.17 Gy, which became supralinear up to 21.75 Gy. This response saturates from 43.5 Gy. All the results were compared with those obtained for TLD-100 chips submitted to the same irradiation conditions. (author)

  10. Work in Greece on Delayed Neutrons

    International Nuclear Information System (INIS)

    At present, two programmes on delayed neutron research are in progress in Greece. Delayed Neutron Energy Spectrum Measurements. In an experiment at the 1 MW Democritus reactor, the energy of the delayed neutrons from 235U fission is measured by the time-of-flight technique and β-n-coincidence using a special fast system for irradiation of the sample. The beta particle preceding the emission of the delayed neutron is used as a start pulse while the delayed neutron provides a stop signal. A maximum flight time of approximately 100 nsec is allowed over a flight distance of approximately 30 cm (longer flight paths could be used for better energy resolution, but this would decrease the efficiency of detecting the delayed neutron). To avoid false measurements due to other beta particles which do not correspond to delayed neutrons, an anti-coincidence system is used to cancel the measurement whenever two beta particles come in a time interval shorter than 100 nsec. Coincidences due to delayed neutrons are relatively rare in comparison with chance coincidences or β-γ-coincidences. The spectrum obtained in a first run of measurements is discussed. An attempt will be made to measure the spectrum of each individual group by varying the irradiation time and the measuring time. Various irradiation, transfer and measuring times can be obtained with the existing experimental set-up. A minimum transfer time of 300 msec can be achieved. Very thin foils (a few mg/cm2) are used to minimize the beta-particle absorption in the sample. Delayed Neutron Group Relative Abundances And Periods. In a second experiment, measurements to determine the relative abundances and periods of the delayed neutrons for various fissile materials are now under way. The arrangement for delayed neutron group measurement allows the sample to be transferred in a minimum time of approximately 800 msec. Accordingly, delayed neutrons of quite short half-lives can be detected. The experimental facility permits

  11. Work in Greece on delayed neutrons

    International Nuclear Information System (INIS)

    At present, two programmes on delayed neutron research are in progress in Greece. DELAYED NEUTRON ENERGY SPECTRUM MEASUREMENTS. In an experiment at the 1 MW Democritus reactor, the energy of the delayed neutrons from 235U fission is measured by the time-of-flight technique and β-n-coincidence using a special fast system for irradiation of the sample. The beta particle preceding the emission of the delayed neutron is used as a start pulse while the delayed neutron provides a stop signal. A maximum flight time of approximately 100 nsec is allowed over a flight distance of approximately 30 cm (longer flight paths could be used for better energy resolution, but this would decrease the efficiency of detecting the delayed neutron). To avoid false measurements due to other beta particles which do not correspond to delayed neutrons, an anti-coincidence system is used to cancel the measurement whenever two beta particles come in a time interval shorter than 100 nsec. Coincidences due to delayed neutrons are relatively rare in comparison with chance coincidences or β-γ-coincidences. The spectrum obtained in a first run of measurements is discussed. An attempt will be made to measure the spectrum of each individual group by varying the irradiation time and the measuring time. Various irradiation, transfer and measuring times can be obtained with the existing experimental set-up. A minimum transfer time of 300 msec can be achieved. Very thin foils (a few mg/cm2) are used to minimize the beta-particle absorption in the sample. DELAYED NEUTRON GROUP RELATIVE ABUNDANCES AND PERIODS. In a second experiment, measurements to determine the relative abundances and periods of the delayed neutrons for various fissile materials are now under way. The arrangement for delayed neutron group measurement allows the sample to be transferred in a minimum time of approximately 800 msec. Accordingly, delayed neutrons of quite short half-lives can be detected. The experimental facility permits

  12. Applications of Beta Particle Detection for Synthesis and Usage of Radiotracers Developed for Positron Emission Tomography

    Science.gov (United States)

    Dooraghi, Alex Abreu

    Positron Emission Tomography (PET) is a noninvasive molecular imaging tool that requires the use of a radioactive compound or radiotracer which targets a molecular pathway of interest. We have developed and employed three beta particle radiation detection systems to advance PET. Specifically, the goals of these systems are to: 1. Automate dispensing of solutions containing a positron emitting isotope. 2. Monitor radioactivity on-chip during synthesis of a positron emitting radiotracer. 3. Assay cellular uptake on-chip of a positron emitting radiotracer. Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing an optimum environment for radiation workers, but also to ensure a quantitatively accurate workflow. For the first project, we describe the development and performance of a system for automated radioactivity distribution of beta particle emitting radioisotopes such as fluorine-18 (F-18). Key to the system is a radiation detector in-line with a peristaltic pump. The system demonstrates volume accuracy within 5 % for volumes of 20 muL or greater. When considering volumes of 20 muL or greater, delivered radioactivity is in agreement with the requested radioactivity as measured with the dose calibrator. The integration of the detector and pump leads to a flexible system that can accurately dispense solutions containing F-18 in radioactivity concentrations directly produced from a cyclotron (~ 0.1-1 mCi/muL), to low activity concentrations intended for preclinical mouse scans (~ 1-10 muCi/muL), and anywhere in between. Electrowetting on dielectric (EWOD) is an attractive microfluidic platform for batch synthesis of PET radiotracers. Visualization of radioisotopes on-chip is critical for synthesis optimization and technological development. For the second project, we describe the development and performance of a Cerenkov/real-time imaging system for PET radiotracer synthesis on EWOD. We also investigate

  13. Scintillation response of CsI: Tl crystal under neutron, gamma, alpha particles and beta excitations

    International Nuclear Information System (INIS)

    Among the converters of X and gamma radiation in light photons, known as scintillators, the one which is the most efficient emits photons with a wavelength near 400 nm. Particularly, among them, the cesium iodine doped with thallium (CsI:Tl) crystal is that which matches better between the light emission spectrum (peak at 540 nm) and the quantum sensitivity curve of the photodiodes and CCD (Charge Coupled Device). This explains the renewed interest in using this crystal as scintillator. Although the CsI:Tl crystal is commercially available, its local development would give the possibility to obtain it in different geometric configurations and coupling. Moreover, there is a special interest in studying new conditions that will alter the properties of this crystal in order to achieve a optimal level of its functional characteristics. Having an efficient national scintillator with low cost is a strategic opportunity to study the response of a detector applied to different types of radiation. The crystal of cesium iodide activated with thallium (CsI:Tl) has a high gamma detection efficiency per unit volume. In this paper, the CsI:Tl crystal, grown by the vertical Bridgman technique in evacuated silica ampoules and with the purpose of use as radiation detectors, is described. To evaluate the scintillator, measures of the thallium distribution in the crystal volume were taken, with overall efficiency score. The scintillator response was studied through gamma radiation from sources of 137Cs, 60Co, 22Na, 54Mn, 131I and 99mTc; the beta radiation from source of 90Sr/90Y, alpha particles from 241Am source and the scintillator response to neutrons from Am/Be source. The energetic resolution for 137Cs gamma rays (662 keV) was 10%. The results showed the validity of using the CsI:Tl crystal developed in our laboratory, in many applications in the area of radiation detectors. (author)

  14. UCTM: A User friendly Configurable Trigger, scaler and delay Module for nuclear and particle physics

    CERN Document Server

    Bourrion, O; Derome, L

    2011-01-01

    A configurable trigger scaler and delay NIM module has been designed to equip nuclear physics experiments and lab teaching classes. It is configurable through a Graphical User Interface (GUI) and provides a large number of possible trigger conditions without any Hardware Description Language (HDL) required knowledge. The design, performances and typical applications are presented.

  15. Optimization of the particle discriminator based on the ballistic deficit method using delay-switched gated integrator

    International Nuclear Information System (INIS)

    The particle discriminator we developed for CsI(Tl) elements of an ancillary detector array planned to be used together with large γ-ray detector systems utilizes the ballistic deficit effect for particle discrimination. This technique applies a low-ballistic-deficit long-time-constant unipolar semi-Gaussian shaper and a large-ballistic-deficit short-time-constant bipolar shaper. To match the signal processing time of our discriminator with that of the standard electronics for Ge detectors the long-time-constant semi-Gaussian shaper was substituted with the so-called delay-switched gated integrator. The experimental tests of the new arrangement show that the pulse processing time can be significantly shortened. The figure of merit of the particle discrimination improves with increasing the total integration time of the delay-switched gated integrator up to 12 μs, above which the improvement is negligible. Therefore, this 12 μs integration time is considered as a good compromise as for the figure of merit and the dead time of the new arrangement. (orig.)

  16. UCTM2: An updated User friendly Configurable Trigger, scaler and delay Module for nuclear and particle physics

    Science.gov (United States)

    Bourrion, O.; Boyer, B.; Derome, L.; Pignol, G.

    2016-06-01

    We developed a highly integrated and versatile electronic module to equip small nuclear physics experiments and lab teaching classes: the User friendly Configurable Trigger, scaler and delay Module for nuclear and particle physics (UCTM). It is configurable through a Graphical User Interface (GUI) and provides a large number of possible trigger conditions without any Hardware Description Language (HDL) required knowledge. This new version significantly enhances the previous capabilities by providing two additional features: signal digitization and time measurements. The design, performances and a typical application are presented.

  17. UCTM2: An updated User friendly Configurable Trigger, scaler and delay Module for nuclear and particle physics

    CERN Document Server

    Bourrion, O; Derome, L; Pignol, G

    2016-01-01

    We developed a highly integrated and versatile electronic module to equip small nuclear physics experiments and lab teaching classes: the User friendly Configurable Trigger, scaler and delay Module for nuclear and particle physics (UCTM). It is configurable through a Graphical User Interface (GUI) and provides a large number of possible trigger conditions without any Hardware Description Language (HDL) required knowledge. This new version significantly enhances the previous capabilities by providing two additional features: signal digitization and time measurements. The design, performances and a typical application are presented.

  18. Mice lacking thyroid hormone receptor Beta show enhanced apoptosis and delayed liver commitment for proliferation after partial hepatectomy.

    Directory of Open Access Journals (Sweden)

    Raquel López-Fontal

    Full Text Available BACKGROUND: The role of thyroid hormones and their receptors (TR during liver regeneration after partial hepatectomy (PH was studied using genetic and pharmacologic approaches. Roles in liver regeneration have been suggested for T3, but there is no clear evidence distinguishing the contribution of increased amounts of T3 from the modulation by unoccupied TRs. METHODOLOGY/PRINCIPAL FINDINGS: Mice lacking TRalpha1/TRbeta or TRbeta alone fully regenerated liver mass after PH, but showed delayed commitment to the initial round of hepatocyte proliferation and transient but intense apoptosis at 48h post-PH, affecting approximately 30% of the remaining hepatocytes. Pharmacologically induced hypothyroidism yielded similar results. Loss of TR activity was associated with enhanced nitrosative stress in the liver remnant, due to an increase in the activity of the nitric oxide synthase (NOS 2 and 3, caused by a transient decrease in the concentration of asymmetric dimethylarginine (ADMA, a potent NOS inhibitor. This decrease in the ADMA levels was due to the presence of a higher activity of dimethylarginineaminohydrolase-1 (DDAH-1 in the regenerating liver of animals lacking TRalpha1/TRbeta or TRbeta. DDAH-1 expression and activity was paralleled by the activity of FXR, a transcription factor involved in liver regeneration and up-regulated in the absence of TR. CONCLUSIONS/SIGNIFICANCE: We report that TRs are not required for liver regeneration; however, hypothyroid mice and TRbeta- or TRalpha1/TRbeta-deficient mice exhibit a delay in the restoration of liver mass, suggesting a specific role for TRbeta in liver regeneration. Altered regenerative responses are related with a delay in the expression of cyclins D1 and E, and the occurrence of liver apoptosis in the absence of activated TRbeta that can be prevented by administration of NOS inhibitors. Taken together, these results indicate that TRbeta contributes significantly to the rapid initial round of

  19. Effects of the dark energy and flat rotation curve on the gravitational time delay of particle with non-zero mass

    Science.gov (United States)

    Sarkar, Tamal; Ghosh, Shubhrangshu; Bhadra, Arunava

    2016-07-01

    The effects of several dark energy models on gravitational time delay of particles with non-zero mass are investigated and analytical expressions for the same are obtained at the first order accuracy. Also the expression for gravitational time delay under the influence of conformal gravity potential that well describes the flat rotation curve of spiral galaxies is derived. The findings suggest that (i) the conformal gravity description of dark matter reduces the net time delay in contrast to the effect of normal dark matter, and therefore in principle the models can be discriminated using gravitational time delay observations, and (ii) the effect of dark energy/flat rotation curve may be revealed from high-precision measurements of gravitational time delay of particles involving the megaparsec and beyond distance scale.

  20. Advanced Time-Delayed Coincidence Studies of $^{31,32}$Mg from the $\\beta$-decays of $^{31,32}$Na

    CERN Multimedia

    Marechal, F; Plociennik, W A

    2002-01-01

    It is proposed to study the lifetime of the 2$_{1}^{+}$ 885.4 keV state in $^{32}$Mg by means of Advanced Time-Delayed $\\beta \\gamma \\gamma$(t) method with the precision in the half-life value of about $\\pm$ 1.5 ps. This would be an independent verification of the B(E2; 0$_{1}^{+} \\rightarrow$ 2$_{1}^{+}$) values obtained so far in a few studies using Coulomb excitations at intermediate beam energies. The advantage of time-delayed coincidence measurements is that they are free of corrections used in the Coulex studies, which strongly affect the deduced B(E2) results. In addition, we propose to study the lifetimes or lifetime limits of other states in nuclei populated in the decays of $^{31}$Na and $^{32}$Na, specifically focusing on the intruder negative parity band in $^{31}$Mg. As a side benefit to this investigation we expect high-quality $\\gamma \\gamma$ coincidences to reveal new excited states in both $^{31}$Mg and $^{32}$Mg. Our results from a brief test-measurement yield a lifetime of T$_{1/2}$ = 10.5(...

  1. Detection of special nuclear material from delayed neutron emission induced by a dual-particle monoenergetic source

    Science.gov (United States)

    Mayer, M.; Nattress, J.; Jovanovic, I.

    2016-06-01

    Detection of unique signatures of special nuclear materials is critical for their interdiction in a variety of nuclear security and nonproliferation scenarios. We report on the observation of delayed neutrons from fission of uranium induced in dual-particle active interrogation based on the 11B(d,n γ)12C nuclear reaction. Majority of the fissions are attributed to fast fission induced by the incident quasi-monoenergetic neutrons. A Li-doped glass-polymer composite scintillation neutron detector, which displays excellent neutron/γ discrimination at low energies, was used in the measurements, along with a recoil-based liquid scintillation detector. Time-dependent buildup and decay of delayed neutron emission from 238U were measured between the interrogating beam pulses and after the interrogating beam was turned off, respectively. Characteristic buildup and decay time profiles were compared to the common parametrization into six delayed neutron groups, finding a good agreement between the measurement and nuclear data. This method is promising for detecting fissile and fissionable materials in cargo scanning applications and can be readily integrated with transmission radiography using low-energy nuclear reaction sources.

  2. Detection of Special Nuclear Material from Delayed Neutron Emission Induced by a Dual-Particle Monoenergetic Source

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Michael F.; Nattress, J.; Jovanovic , I

    2016-06-30

    Detection of unique signatures of special nuclear materials is critical for their interdiction in a variety of nuclear security and nonproliferation scenarios. We report on the observation of delayed neutrons from fission of uranium induced in dual-particle active interrogation based on the 11B(d,n gamma)12C nuclear reaction. Majority of the fissions are attributed to fast fission induced by the incident quasi-monoenergetic neutrons. A Li-doped glass–polymer composite scintillation neutron detector, which displays excellent neutron/γ discrimination at low energies, was used in the measurements, along with a recoil-based liquid scintillation detector. Time- dependent buildup and decay of delayed neutron emission from 238U were measured between the interrogating beam pulses and after the interrogating beam was turned off, respectively. Characteristic buildup and decay time profiles were compared to the common parametrization into six delayed neutron groups, finding a good agreement between the measurement and nuclear data. This method is promising for detecting fissile and fissionable materials in cargo scanning applications and can be readily integrated with transmission radiography using low-energy nuclear reaction sources.

  3. Beta-delayed proton emission: a new series of precursors and the measurement of 10-16 s nuclear lifetimes

    International Nuclear Information System (INIS)

    We have now obtained results on a new series of even-Z precursors with Tsub(z) = +1/2. Like all known heavy precursors, the nuclei so far identified - 65Ge, 69Se, 73Kr, 77Sr, 81Zr and provisionally 85Mo - exhibit broad proton continua. However, the availability of such a series of nuclei makes it possible to extract a systematic picture of the beta-decay strength function as well as level densities, widths and decay energies from the observed spectra. By the addition of a new experimental technique we have also been able to determine the absolute values of the widths through direct measurement of the average lifetime of states populated in the emitter. These data all provide stringent tests of model calculations and mass formulae in a region of nuclei with N approximately Z, far removed from the valley of stability. (author)

  4. Beta-decay properties of Zr and Mo neutron-rich isotopes

    OpenAIRE

    Sarriguren, P.; Pereira, J

    2010-01-01

    Gamow-Teller strength distributions, beta-decay half-lives, and beta-delayed neutron emission are investigated in neutron-rich Zr and Mo isotopes within a deformed quasiparticle random-phase approximation. The approach is based on a self-consistent Skyrme Hartree-Fock mean field with pairing correlations and residual separable particle-hole and particle-particle forces. Comparison with recent measurements of half-lives stresses the important role that nuclear deformation plays in the descript...

  5. The implications of particle energy and acidic media on gross alpha and gross beta determination using liquid scintillation

    Energy Technology Data Exchange (ETDEWEB)

    Zapata-Garcia, D. [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain); Llaurado, M., E-mail: montse.llaurado@ub.edu [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain); Rauret, G. [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain)

    2012-04-15

    The interaction of humans with radioactivity present in the environment from natural and artificial sources necessitates an evaluation of its risk on human health. Gross alpha and gross beta activities can provide a rapid evaluation of the radioactive content of a sample and can be simultaneously determined by using liquid scintillation counters. However, calibration of the liquid scintillation counter is required and is affected by many factors, such as particle energy and the acidity of the media. This study investigates what effect the particle energy used for calibration has on misclassification and how to account for this misclassification in routine measurements. The variability in measurement produced by the final pH, as well as any acids used in sample treatment, was also studied. These results showed that the most commonly used acid for these types of analyses, HNO{sub 3}, produced a high amount of misclassifications at very low pH. The results improved when HCl was used to adjust the sample to low pH. - Highlights: Black-Right-Pointing-Pointer We study the effect of alpha and beta energies on PSA optimisation. Black-Right-Pointing-Pointer The optimum PSA shifts to higher values as the alpha energy increases. Beta energies do not affect it. Black-Right-Pointing-Pointer We study the effect of pH on the simultaneous determination of gross alpha/beta activities. Black-Right-Pointing-Pointer HNO{sub 3} produces a high amount of misclassification at very low pH. Black-Right-Pointing-Pointer The results improve when HCl is used to adjust the sample to low pH.

  6. NBS (National Bureau of Standards) measurement services: calibration of beta-particle-emitting ophthalmic applicators. Final report

    International Nuclear Information System (INIS)

    The service provides calibrations for (90)Sr + (90)Y beta-particle ophthalmic applicators. The calibration determines the average surface absorbed-dose rate to water over the active area of the applicator. The technique used is to measure current per unit mass of air at the active surface with an extrapolation ionization chamber, and to convert this into absorbed-dose rate with Bragg-Gray cavity ionization theory. The extrapolation chamber measurements are made in three parts. Data-book measurements and a calibration report are given for one particular applicator

  7. Calculation of Beta Decay Half-Lives and Delayed Neutron Branching Ratio of Fission Fragments with Skyrme-QRPA

    Directory of Open Access Journals (Sweden)

    Minato Futoshi

    2016-01-01

    Full Text Available Nuclear β-decay and delayed neutron (DN emission is important for the r-process nucleosynthesis after the freeze-out, and stable and safe operation of nuclear reactors. Even though radioactive beam facilities have enabled us to measure β-decay and branching ratio of neutron-rich nuclei apart from the stability line in the nuclear chart, there are still a lot of nuclei which one cannot investigate experimentally. In particular, information on DN is rather scarce than that of T1/2. To predict T1/2 and the branching ratios of DN for next JENDL decay data, we have developed a method which comprises the quasiparticle-random-phase-approximation (QRPA and the Hauser-Feshbach statistical model (HFSM. In this work, we calculate fission fragments with T1/2 ≤ 50 sec. We obtain the rms deviation from experimental half-life of 3:71. Although the result is still worse than GT2 which has been adopted in JENDL decay data, DN spectra are newly calculated. We also discuss further subjects to be done in future for improving the present approach and making next generation of JENDL decay data.

  8. Calculation of Beta Decay Half-Lives and Delayed Neutron Branching Ratio of Fission Fragments with Skyrme-QRPA

    Science.gov (United States)

    Minato, Futoshi

    2016-06-01

    Nuclear β-decay and delayed neutron (DN) emission is important for the r-process nucleosynthesis after the freeze-out, and stable and safe operation of nuclear reactors. Even though radioactive beam facilities have enabled us to measure β-decay and branching ratio of neutron-rich nuclei apart from the stability line in the nuclear chart, there are still a lot of nuclei which one cannot investigate experimentally. In particular, information on DN is rather scarce than that of T1/2. To predict T1/2 and the branching ratios of DN for next JENDL decay data, we have developed a method which comprises the quasiparticle-random-phase-approximation (QRPA) and the Hauser-Feshbach statistical model (HFSM). In this work, we calculate fission fragments with T1/2 ≤ 50 sec. We obtain the rms deviation from experimental half-life of 3:71. Although the result is still worse than GT2 which has been adopted in JENDL decay data, DN spectra are newly calculated. We also discuss further subjects to be done in future for improving the present approach and making next generation of JENDL decay data.

  9. Quality assurance of personal beta particle dosemeters used for individual monitoring of occupationally exposed persons

    International Nuclear Information System (INIS)

    As a result of investigations and intercomparison measurements organised from 1996 to 1999 by PTB, several types of personal dosemeters, all based on TLD, were selected by the dosimetry services for the measurement of the personal dose equivalent Hp(0.07) in beta and/or photon radiation fields. These dosemeters have now the status of legal personal beta partial-body dosemeters. Workplaces at which beta radiation might significantly contribute to the doses to the extremities are to be found today with increasing frequency in radiation therapy, radiation source production and nuclear power plants. Quality assurance for beta personal dosemeters is stipulated by guidelines for the official dosimetry service and is carried out by way of the intercomparison measurements organised periodically by the PTB. The results are evaluated based on the recommendations of the German Commission on Radiological Protection (SSK). The procedure of these intercomparison measurements will be explained in detail. The experience gained from three series of comparisons with seven types of fingering dosemeters will be described and the results will be presented. The anonymity of the dosemeter types and of the participants in the intercomparison will be preserved. (authors)

  10. Quality assurance of personal beta-particle dosimeters used for individual monitoring of occupationally exposed persons

    International Nuclear Information System (INIS)

    Full text: As a result of investigations and intercomparison measurements organized from 1996 to 1999 by PTB several types of personal dosemeters, all based on TLD, were selected by the dosimetry services for the measurement of the personal dose equivalent Hp(0.07) in beta and/or photon radiation fields. These dosemeters have now the status of legal personal beta partial-body dosemeters. Workplaces, at which beta radiation might significantly contribute to the doses to the extremities, appear with increasing frequency in radiation therapy, at radiation source production and in nuclear power plants. Quality assurance for beta personal dosemeters is stipulated by guidelines for the official dosimetry service and is carried out by way of the intercomparison measurements organized periodically by the PTB. The results are evaluated on the basis of recommendations of the German Commission on Radiological Protection (SSK). The procedure of these intercomparison measurements will be explained in detail. The experience gained from three series of comparisons with seven types of fingerring dosemeters will be described and the results will be presented. The anonymity of the dosemeter types and of the participants in the intercomparison will be preserved. (author)

  11. Influence of hydrophobic Teflon particles on the structure of amyloid beta-peptide

    NARCIS (Netherlands)

    Giacomelli, CE; Norde, W

    2003-01-01

    The amyloid beta-protein (Abeta) constitutes the major peptide component of the amyloid plaque deposits of Alzheimer's disease in humans. The Abeta changes from a nonpathogenic to a pathogenic conformation resulting in self-aggregation and deposition of the peptide. It has been established that dena

  12. Parameters identification of unknown delayed genetic regulatory networks by a switching particle swarm optimization algorithm

    OpenAIRE

    Tang, Y.; Wang, Z; J. Fang

    2011-01-01

    The official published version can be found at the link below. This paper presents a novel particle swarm optimization (PSO) algorithm based on Markov chains and competitive penalized method. Such an algorithm is developed to solve global optimization problems with applications in identifying unknown parameters of a class of genetic regulatory networks (GRNs). By using an evolutionary factor, a new switching PSO (SPSO) algorithm is first proposed and analyzed, where the velocity updating e...

  13. Epoetin beta pegol alleviates oxidative stress and exacerbation of renal damage from iron deposition, thereby delaying CKD progression in progressive glomerulonephritis rats.

    Science.gov (United States)

    Hirata, Michinori; Tashiro, Yoshihito; Aizawa, Ken; Kawasaki, Ryohei; Shimonaka, Yasushi; Endo, Koichi

    2015-12-01

    The increased deposition of iron in the kidneys that occurs with glomerulopathy hinders the functional and structural recovery of the tubules and promotes progression of chronic kidney disease (CKD). Here, we evaluated whether epoetin beta pegol (continuous erythropoietin receptor activator: CERA), which has a long half-life in blood and strongly suppresses hepcidin-25, exerts renoprotection in a rat model of chronic progressive glomerulonephritis (cGN). cGN rats showed elevated urinary total protein excretion (uTP) and plasma urea nitrogen (UN) from day 14 after the induction of kidney disease (day 0) and finally declined into end-stage kidney disease (ESKD), showing reduced creatinine clearance with glomerulosclerosis, tubular dilation, and tubulointerstitial fibrosis. A single dose of CERA given on day 1, but not on day 16, alleviated increasing uTP and UN, thereby delaying ESKD. In the initial disease phase, CERA significantly suppressed urinary 8-OHdG and liver-type fatty acid-binding protein (L-FABP), a tubular damage marker. CERA also inhibited elevated plasma hepcidin-25 levels and alleviated subsequent iron accumulation in kidneys in association with elevated urinary iron excretion and resulted in alleviation of growth of Ki67-positive tubular and glomerular cells. In addition, at day 28 when the exacerbation of uTP occurs, a significant correlation was observed between iron deposition in the kidney and urinary L-FABP. In our study, CERA mitigated increasing kidney damage, thereby delaying CKD progression in this glomerulonephritis rat model. Alleviation by CERA of the exacerbation of kidney damage could be attributable to mitigation of tubular damage that might occur with lowered iron deposition in tubules. PMID:26634903

  14. The influence of chemical and color quenching on the shape of energy spectrum for Beta particles of 90Sr- 90Y by using liquid scintillation cocktail

    International Nuclear Information System (INIS)

    The effect of chemical quenching on the pulse height spectrum and Emax of Strontium 90Sr were studied using the organic scintillation cocktail and observing change in florescent yield and spectral shape (energy spectrum) of beta particles of 90Sr isotope in determining a relationship between the magnitude of material that causes quenching and the position of energy spectrum and Emax, adding 3 M nitric acid (HNO3) as chemical quencher to the scintillation, and added aqueous soluble yellow food dye with different concentration as color quencher. The beta detection efficiency depends on energy, spectral shape and cocktail. Typically, beta particles with maximum energies (Emax > 0.250 MeV) are detected with > 90% counting efficiency in organic liquid scintillation, where 90Sr has maximum beta energy, Emax, of 0.546 MeV and half-life of 28.17 years. The results were compared with reference and literature values. (author)

  15. Particle-tracking calculation of classical transport in high-beta field-reversed configuration plasma

    International Nuclear Information System (INIS)

    In this paper, classical particle transport processes in field-reversed configuration plasma is investigated by particle-tracking calculations. The end-loss rate is found to increase with ion temperature, and the temperature dependence is much stronger than that of the Bohm scaling and the empirical scaling. (author)

  16. Magneto-Hydrodynamic Activity and Energetic Particles - Application to Beta Alfvén Eigenmodes.

    OpenAIRE

    Nguyen, Christine

    2009-01-01

    The goal of magnetic fusion research is to extract the power released by fusion reactions and carried by the product of these reactions, liberated at energies of the order of a few MeV. The feasibility of fusion energy production relies on our ability to confine these energetic particles, while keeping the thermonuclear plasma in safe operating conditions. For that purpose, it is necessary to understand and find ways to control the interaction between energetic particles and the thermonuclear...

  17. Magneto-HydroDynamic activity and Energetic Particles - Application to Beta Alfven Eigenmodes

    OpenAIRE

    Nguyen, Christine

    2009-01-01

    The goal of magnetic fusion research is to extract the power released by fusion reactions and carried by the product of these reactions, liberated at energies of the order of a few MeV. The feasibility of fusion energy production relies on our ability to confine these energetic particles, while keeping the thermonuclear plasma in safe operating conditions. For that purpose, it is necessary to understand and find ways to control the interaction between energetic particles and the thermonuclear...

  18. Beta Androstenediol Mitigates the Damage of 1 GeV/n Fe Ion Particle Radiation to the Hematopoietic System

    Energy Technology Data Exchange (ETDEWEB)

    Loria R.; Guida P.; Loria, R.; Beckman, M.; Contaifer, D.; Tamariz, F.; Gibb, D.; Thompson, L.; Guida, P.

    2010-09-07

    Space exploration is associated with exposure to 1-3 Gy solar particle radiation and galactic cosmic radiation that could increase cancer rates. Effective nontoxic countermeasures to high linear energy transfer (LET) radiation exposure are highly desirable but currently not available. The aim was to determine whether a single subcutaneous injection of androstenediol ({Delta}(5) androsten-3{beta}, 17{beta}-diol [AED]) could mitigate and restore the mouse hematopoetic system from the radiation-mediated injury of 3 Gy whole-body high LET (56)Fe(26+) exposure. The findings show that postradiation AED treatment has an overall positive and significant beneficial effect to restore the levels of hematopoeitic elements (p < 0.001). Androstenediol treatment significantly increased monocyte levels at days 4, 7, and 14 and, similarly, increased red blood cell, hemoglobin, and platelet counts. Flow cytometry analysis 14 days after radiation and AED treatment demonstrated an increase (p < 0.05) in bone marrow cells counts. Ex vivo osteoclastogenesis studies show that AED treatment is necessary and advantageous for the development and restoration of osteoclastogenesis after radiation exposure. These findings clearly show that androstenediol functions as a countermeasure to remedy hematopoeitic injury mediated by high LET iron ion radiation. Presently, no other agent has been shown to have such properties.

  19. Synthesis and thermoluminescent characterization of new matches of LiF:Eu exposed to beta particles

    International Nuclear Information System (INIS)

    Full text: LiF has been and currently is a base material in the preparation of commercial dosimeters due to its characteristics and dosimetric properties. Obtain a material that has stable and sensitive characteristics is what is sought in the field of dosimetry. Pellets were manufactured with different concentrations of dopant (EuCl3) ranging between 0.5, 1.0, 1.5% mol, using the coprecipitation method, these pellets were synthesized at 750 degrees C for 5 hours. The concentration of dopant with the best characteristics is 1.5% mol of EuCl3. During the thermoluminescent characterization, the pellets were subjected to various doses of beta radiation ranging from 0.5 to 2.5 Gy, yielding glow curves that increase the intensity of the Tl signal with increasing radiation dose. The results also show good reproducibility, with a main peak around 250 degrees C and a low fading of thermoluminescent signal. (Author)

  20. Dosimetry of beta particles using Li:Mg, Cu, P + Ptfe

    International Nuclear Information System (INIS)

    This paper presents the experimental results of determining the thermoluminescence (Tl) response of LiF: Mg, Cu, P + Ptfe pellets excited with 90Sr/90Y beta radiation. The glow curve exhibited three peaks which appear at 121 C, 178 C and 217 C . Its relative sensitivity is 49 with respect to that of the TLD-100 dosemeter taken as a reference. The minimal dose that could be measured was 750 mGy. The Tl response as a function of dose was linear in the range of 0.7 mGy to 22.5 mGy. The study of the repeatability of the information contained in the pellets showed a standard deviation of 2 %. (Author)

  1. Automatic instrument for aerosol samples using the beta-particle attenuation

    International Nuclear Information System (INIS)

    This work describes an instrument developed for the routine measurement of aerosol mass using the β-particle attenuation method. The design of the present instrument is particularly well suited for the automatic mass measurement of membrane filters used for the collection of airborne particles. The instrument uses electromechanical devices for the automatic positioning of filters in the sampling and measuring holders and the return to their stand by locations, where the filters are stored for off-line testing purposes and documentation. The instrument is designed with very low system 'dead time' and high sensitivity. (author)

  2. Beta-decay properties of Zr and Mo neutron-rich isotopes

    CERN Document Server

    Sarriguren, P

    2010-01-01

    Gamow-Teller strength distributions, beta-decay half-lives, and beta-delayed neutron emission are investigated in neutron-rich Zr and Mo isotopes within a deformed quasiparticle random-phase approximation. The approach is based on a self-consistent Skyrme Hartree-Fock mean field with pairing correlations and residual separable particle-hole and particle-particle forces. Comparison with recent measurements of half-lives stresses the important role that nuclear deformation plays in the description of beta-decay properties in this mass region.

  3. Evaluation of a low background proportional counter for detection of high energy beta particles with application to {sup 90}Sr surface contamination

    Energy Technology Data Exchange (ETDEWEB)

    Islam, K.T.S.; Johnson, L.; Brey, R.R.; Gesell, T.F. [Idaho State Univ., Pocatello, ID (United States); McIsaac, C. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)

    1996-06-01

    Conventional radiochemical methods used to quantify {sup 90}Sr are complicated and time-consuming. A relatively simple, inexpensive instrument has been developed for analysis of high energy beta surface contamination in the presence of lower energy beta emitters. The instrument detects beta particles from {sup 90}Y, which is in secular equilibrium with {sup 90}Sr. The device consists of three stacked gas-flow proportional detectors. The bottom two are operated in coincidence mode and the top detector is operated in anti-coincidence to the others for reducing cosmic-ray background. Shielding is used to reduce the background from terrestrial sources. The thickness of the bottom two counters eliminates beta particles with energies below 660 keV from the second detector. The end-point energy of the {sup 90}Sr beta is 546 KeV, while that for {sup 90}Y is 2.28 MeV. Greater than 69% of the particles emitted during the decay of {sup 90}Y have energies above the endpoint energy of {sup 90}Sr. Because of these conditions, this instrument, which has an efficiency of about 10%, is practical for measurements near environmental magnitudes. The instrument is expected to have application in decontamination and decommissioning, decisions concerning release of materials, and waste management.

  4. Evaluation of a low background proportional counter for detection of high energy beta particles with application to 90Sr surface contamination

    International Nuclear Information System (INIS)

    Conventional radiochemical methods used to quantify 90Sr are complicated and time-consuming. A relatively simple, inexpensive instrument has been developed for analysis of high energy beta surface contamination in the presence of lower energy beta emitters. The instrument detects beta particles from 90Y, which is in secular equilibrium with 90Sr. The device consists of three stacked gas-flow proportional detectors. The bottom two are operated in coincidence mode and the top detector is operated in anti-coincidence to the others for reducing cosmic-ray background. Shielding is used to reduce the background from terrestrial sources. The thickness of the bottom two counters eliminates beta particles with energies below 660 keV from the second detector. The end-point energy of the 90Sr beta is 546 KeV, while that for 90Y is 2.28 MeV. Greater than 69% of the particles emitted during the decay of 90Y have energies above the endpoint energy of 90Sr. Because of these conditions, this instrument, which has an efficiency of about 10%, is practical for measurements near environmental magnitudes. The instrument is expected to have application in decontamination and decommissioning, decisions concerning release of materials, and waste management

  5. Radiation-induced ionization and excitation in liquid p-dioxane. [Beta particles

    Energy Technology Data Exchange (ETDEWEB)

    Ausloos, P.; Lutz, C.; Schwarz, F.; Lias, S.G. (National Bureau of Standards, Washington, DC (USA). Center for Chemical Physics)

    1984-01-01

    The fluorescence of neat liquid p-dioxane and p-dioxane-water mixtures has been studied as a function of wavelength in the range 200 to 110 nm, and in the system under beta irradiation. It is seen that the quantum yield of fluorescence declines from the absorption threshold to the ionization onset (approx. 160 to 170 nm), because of the increasing importance of the competing decomposition processes. Above the ionization onset, there is a slight increase in the quantum yield of fluorescence as a result of the occurrence of 'recombination fluorescence'. However, it is estimated that in this region, neutralization does not always lead to a vibrationally equilibrated excited state. This explains in part why the G-value of thermally equilibrated S/sub 1/ states is considerably lower than G(ion)(approx. 5), under conditions that fluorescence originates mainly from charge recombination. Auxiliary experiments carried out in the gas phase, in an ion cyclotron resonance spectrometer, elucidated the reaction of p-C/sub 4/H/sub 8/O/sub 2//sup +/ ions with p-dioxane molecules. The results indicate that in the gas phase, proton transfer between these reactants is thermoneutral, and occurs with a lowered efficiency in contrast with m-dioxane for which the corresponding proton transfer reaction is highly exothermic and ksub(Rn) = ksub(Collision).

  6. Study of the Z-dependence of external bremsstrahlung produced by beta particles of sup 1 sup 4 sup 7 Pm and sup 3 sup 2 P

    CERN Document Server

    Dhaliwal, A S

    2003-01-01

    The Z-dependence of external bremsstrahlung (EB) produced by beta particles of sup 1 sup 4 sup 7 Pm and sup 3 sup 2 P beta emitters in Al, Cu, Sn, and Pb targets has been studied, as a function of photon energy, on the basis of the theoretical and experimental EB spectral distributions. The present results show that the values of the Z-dependence index, obtained both from Elwert-corrected Bethe-Heitler and Tseng and Pratt theories and from experiments, are not constant. It is found that the index n increases with increasing photon energy.

  7. The dynamics of low-beta plasma clouds as simulated by a three-dimensional, electromagnetic particle code

    Science.gov (United States)

    Neubert, T.; Miller, R. H.; Buneman, O.; Nishikawa, K.-I.

    1992-01-01

    A 3D electromagnetic and relativistic particle simulation code is used to investigate the dynamics of low-beta plasma clouds moving perpendicular to an ambient magnetic field in vacuum and in a background plasma. The simulations show the formation of the space charge sheaths at the sides of the cloud with the associated polarization electric field which facilitate the cross-field propagation, as well as the sheaths at the front and rear end of the cloud caused by the larger ion Larmor radius, which allows ions to move ahead and lag behind the electrons as they gyrate. It is found that, in a background plasma, electron and ion sheaths expand along the magnetic field at the same rate, whereas in vacuum the electron sheath expands much faster than the ion sheath. Sheath clouds are accelerated up to relativistic energies, which indicates that artificial plasma clouds released in the ionosphere or magnetosphere may generate optical emissions as energetic sheath electrons scatter in the upper atmosphere.

  8. PARTICLE-IN-CELL SIMULATIONS OF CONTINUOUSLY DRIVEN MIRROR AND ION CYCLOTRON INSTABILITIES IN HIGH BETA ASTROPHYSICAL AND HELIOSPHERIC PLASMAS

    Energy Technology Data Exchange (ETDEWEB)

    Riquelme, Mario A. [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago (Chile); Quataert, Eliot [Astronomy Department and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States); Verscharen, Daniel, E-mail: mario.riquelme@dfi.uchile.cl, E-mail: eliot@berkeley.edu, E-mail: Daniel.Verscharen@unh.edu [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States)

    2015-02-10

    We use particle-in-cell simulations to study the nonlinear evolution of ion velocity space instabilities in an idealized problem in which a background velocity shear continuously amplifies the magnetic field. We simulate the astrophysically relevant regime where the shear timescale is long compared to the ion cyclotron period, and the plasma beta is β ∼ 1-100. The background field amplification in our calculation is meant to mimic processes such as turbulent fluctuations or MHD-scale instabilities. The field amplification continuously drives a pressure anisotropy with p > p {sub ∥} and the plasma becomes unstable to the mirror and ion cyclotron instabilities. In all cases, the nonlinear state is dominated by the mirror instability, not the ion cyclotron instability, and the plasma pressure anisotropy saturates near the threshold for the linear mirror instability. The magnetic field fluctuations initially undergo exponential growth but saturate in a secular phase in which the fluctuations grow on the same timescale as the background magnetic field (with δB ∼ 0.3 (B) in the secular phase). At early times, the ion magnetic moment is well-conserved but once the fluctuation amplitudes exceed δB ∼ 0.1 (B), the magnetic moment is no longer conserved but instead changes on a timescale comparable to that of the mean magnetic field. We discuss the implications of our results for low-collisionality astrophysical plasmas, including the near-Earth solar wind and low-luminosity accretion disks around black holes.

  9. PARTICLE-IN-CELL SIMULATIONS OF CONTINUOUSLY DRIVEN MIRROR AND ION CYCLOTRON INSTABILITIES IN HIGH BETA ASTROPHYSICAL AND HELIOSPHERIC PLASMAS

    International Nuclear Information System (INIS)

    We use particle-in-cell simulations to study the nonlinear evolution of ion velocity space instabilities in an idealized problem in which a background velocity shear continuously amplifies the magnetic field. We simulate the astrophysically relevant regime where the shear timescale is long compared to the ion cyclotron period, and the plasma beta is β ∼ 1-100. The background field amplification in our calculation is meant to mimic processes such as turbulent fluctuations or MHD-scale instabilities. The field amplification continuously drives a pressure anisotropy with p > p ∥ and the plasma becomes unstable to the mirror and ion cyclotron instabilities. In all cases, the nonlinear state is dominated by the mirror instability, not the ion cyclotron instability, and the plasma pressure anisotropy saturates near the threshold for the linear mirror instability. The magnetic field fluctuations initially undergo exponential growth but saturate in a secular phase in which the fluctuations grow on the same timescale as the background magnetic field (with δB ∼ 0.3 (B) in the secular phase). At early times, the ion magnetic moment is well-conserved but once the fluctuation amplitudes exceed δB ∼ 0.1 (B), the magnetic moment is no longer conserved but instead changes on a timescale comparable to that of the mean magnetic field. We discuss the implications of our results for low-collisionality astrophysical plasmas, including the near-Earth solar wind and low-luminosity accretion disks around black holes

  10. Analysis of Deep Level Defects in GaN p-i-n Diodes after Beta Particle Irradiation

    Directory of Open Access Journals (Sweden)

    Sofiane Belahsene

    2015-12-01

    Full Text Available The effect of beta particle irradiation (electron energy 0.54 MeV on the electrical characteristics of GaN p-i-n diodes is investigated by current-voltage (I-V, capacitance-voltage (C-V and deep-level transient spectroscopy (DLTS measurements. The experimental studies show that, for the as-grown samples, three electron traps are found with activation energies ranging from 0.06 to 0.81 eV and concentrations ranging from 1.2 × 1014 to 3.6 × 1015 cm−3, together with one hole trap with energy depth of 0.83 eV and concentration of 8 × 1014 cm−3. It has been found that the irradiation has no effect on these intrinsic defects. The irradiation affected only a shallow donor level close to Ec [0.06 eV-0.18 eV] on the p-side of the p-i-n junction.

  11. Utilization of wavelength-shifting fibers coupled to ZnS(Ag) and plastic scintillator for simultaneous detection of alpha/beta particles

    International Nuclear Information System (INIS)

    Low level radioactive surface contamination measurements require lightweight, large area and high efficiency detector. In most existing scintillation detectors there is a tradeoff between effective area and scintillation light collection. By using wavelength shifting (WLS) fibers the scintillation light may be collected efficiently also in a large area detector. In this study, WLS fibers were coupled to a beta sensitive plastic scintillator layer and to a alpha sensitive silver-activated zinc sulfide ZnS(Ag) layer for detecting both alpha and beta particles. The WLS fibers collect the scintillation light from the whole detector and transfer it to a single PMT. This first prototype unique configuration enables monitoring radioactive contaminated surfaces by both sides of the detector and provides high gamma rejection. In this paper, the detector structure, as well as the detector’s measured linear response, will be described. The measured detection efficiency of 238Pu alpha particles (5.5 MeV) is ~63%. The measured detection efficiency for beta particles is ~89% for 90Sr–90Y (average energy of 195.8 keV, 934.8 keV), ~50% for 36Cl (average energy of 251.3 keV), and 35% for 137Cs (average energy of 156.8 keV)

  12. Utilization of wavelength-shifting fibers coupled to ZnS(Ag) and plastic scintillator for simultaneous detection of alpha/beta particles

    Science.gov (United States)

    Ifergan, Y.; Dadon, S.; Israelashvili, I.; Osovizky, A.; Gonen, E.; Yehuda-Zada, Y.; Smadja, D.; Knafo, Y.; Ginzburg, D.; Kadmon, Y.; Cohen, Y.; Mazor, T.

    2015-06-01

    Low level radioactive surface contamination measurements require lightweight, large area and high efficiency detector. In most existing scintillation detectors there is a tradeoff between effective area and scintillation light collection. By using wavelength shifting (WLS) fibers the scintillation light may be collected efficiently also in a large area detector. In this study, WLS fibers were coupled to a beta sensitive plastic scintillator layer and to a alpha sensitive silver-activated zinc sulfide ZnS(Ag) layer for detecting both alpha and beta particles. The WLS fibers collect the scintillation light from the whole detector and transfer it to a single PMT. This first prototype unique configuration enables monitoring radioactive contaminated surfaces by both sides of the detector and provides high gamma rejection. In this paper, the detector structure, as well as the detector's measured linear response, will be described. The measured detection efficiency of 238Pu alpha particles (5.5 MeV) is ~63%. The measured detection efficiency for beta particles is ~89% for 90Sr-90Y (average energy of 195.8 keV, 934.8 keV), ~50% for 36Cl (average energy of 251.3 keV), and 35% for 137Cs (average energy of 156.8 keV).

  13. Utilization of wavelength-shifting fibers coupled to ZnS(Ag) and plastic scintillator for simultaneous detection of alpha/beta particles

    Energy Technology Data Exchange (ETDEWEB)

    Ifergan, Y., E-mail: Yairifergan@gmail.com [Electronics & Control Laboratories, Nuclear Research Center Negev, PO Box 9001, Beer Sheva (Israel); Dadon, S. [Electronics & Control Laboratories, Nuclear Research Center Negev, PO Box 9001, Beer Sheva (Israel); Israelashvili, I. [Physics Department, Nuclear Research Center of the Negev, PO Box 9001, Beer Sheva (Israel); Osovizky, A. [Radiation Detection Department, Rotem Industries Ltd, Beer Sheva (Israel); Gonen, E.; Yehuda-Zada, Y.; Smadja, D. [Electronics & Control Laboratories, Nuclear Research Center Negev, PO Box 9001, Beer Sheva (Israel); Knafo, Y.; Ginzburg, D. [Radiation Detection Department, Rotem Industries Ltd, Beer Sheva (Israel); Kadmon, Y.; Cohen, Y.; Mazor, T. [Electronics & Control Laboratories, Nuclear Research Center Negev, PO Box 9001, Beer Sheva (Israel)

    2015-06-01

    Low level radioactive surface contamination measurements require lightweight, large area and high efficiency detector. In most existing scintillation detectors there is a tradeoff between effective area and scintillation light collection. By using wavelength shifting (WLS) fibers the scintillation light may be collected efficiently also in a large area detector. In this study, WLS fibers were coupled to a beta sensitive plastic scintillator layer and to a alpha sensitive silver-activated zinc sulfide ZnS(Ag) layer for detecting both alpha and beta particles. The WLS fibers collect the scintillation light from the whole detector and transfer it to a single PMT. This first prototype unique configuration enables monitoring radioactive contaminated surfaces by both sides of the detector and provides high gamma rejection. In this paper, the detector structure, as well as the detector’s measured linear response, will be described. The measured detection efficiency of {sup 238}Pu alpha particles (5.5 MeV) is ~63%. The measured detection efficiency for beta particles is ~89% for {sup 90}Sr–{sup 90}Y (average energy of 195.8 keV, 934.8 keV), ~50% for {sup 36}Cl (average energy of 251.3 keV), and 35% for {sup 137}Cs (average energy of 156.8 keV)

  14. Transport of carbon ion test particles and hydrogen recycling in the plasma of the Columbia tokamak ''HBT'' [High Beta Tokamak

    International Nuclear Information System (INIS)

    Carbon impurity ion transport is studied in the Columbia High Beta Tokamak (HBT), using a carbon tipped probe which is inserted into the plasma (ne ∼ 1 - 5 x 1014 (cm-3), Te ∼ 4 - 10 (eV), Bt ∼ 0.2 - 0.4(T)). Carbon impurity light, mainly the strong lines of CII(4267A, emitted by the C+ ions) and CIII (4647A, emitted by the C++ ions), is formed by the ablation or sputtering of plasma ions and by the discharge of the carbon probe itself. The diffusion transport of the carbon ions is modeled by measuring the space-and-time dependent spectral light emission of the carbon ions with a collimated optical beam and photomultiplier. The point of emission can be observed in such a way as to sample regions along and transverse to the toroidal magnetic field. The carbon ion diffusion coefficients are obtained by fitting the data to a diffusion transport model. It is found that the diffusion of the carbon ions is ''classical'' and is controlled by the high collisionality of the HBT plasma; the diffusion is a two-dimensional problem and the expected dependence on the charge of the impurity ion is observed. The measurement of the spatial distribution of the Hα emissivity was obtained by inverting the light signals from a 4-channel polychromator, the data were used to calculate the minor-radial influx, the density, and the recycling time of neutral hydrogen atoms or molecules. The calculation shows that the particle recycling time τp is comparable with the plasma energy confinement time τE; therefore, the recycling of the hot plasma ions with the cold neutrals from the walls is one of the main mechanisms for loss of plasma energy

  15. The ATM kinase signaling induced by the low-energy {beta}-particles emitted by {sup 33}P is essential for the suppression of chromosome aberrations and is greater than that induced by the energetic {beta}-particles emitted by {sup 32}P

    Energy Technology Data Exchange (ETDEWEB)

    White, Jason S.; Yue Ning [Department of Radiation Oncology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States); Hu Jing [Department of Pharmacology and Chemical Biology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States); Bakkenist, Christopher J., E-mail: bakkenistcj@upmc.edu [Department of Radiation Oncology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States); Department of Pharmacology and Chemical Biology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States)

    2011-03-15

    Ataxia-telangiectasia mutated (ATM) encodes a nuclear serine/threonine protein kinase whose activity is increased in cells exposed to low doses of ionizing radiation (IR). Here we examine ATM kinase activation in cells exposed to either {sup 32}P- or {sup 33}P-orthophosphate under conditions typically employed in metabolic labelling experiments. We calculate that the absorbed dose of IR delivered to a 5 cm x 5 cm monolayer of cells incubated in 2 ml media containing 1 mCi of the high-energy (1.70 MeV) {beta}-particle emitter {sup 32}P-orthophosphate for 30 min is {approx}1 Gy IR. The absorbed dose of IR following an otherwise identical exposure to the low-energy (0.24 MeV) {beta}-particle emitter {sup 33}P-orthophosphate is {approx}0.18 Gy IR. We show that low-energy {beta}-particles emitted by {sup 33}P induce a greater number of ionizing radiation-induced foci (IRIF) and greater ATM kinase signaling than energetic {beta}-particles emitted by {sup 32}P. Hence, we demonstrate that it is inappropriate to use {sup 33}P-orthophosphate as a negative control for {sup 32}P-orthophosphate in experiments investigating DNA damage responses to DNA double-strand breaks (DSBs). Significantly, we show that ATM accumulates in the chromatin fraction when ATM kinase activity is inhibited during exposure to either radionuclide. Finally, we also show that chromosome aberrations accumulate in cells when ATM kinase activity is inhibited during exposure to {approx}0.36 Gy {beta}-particles emitted by {sup 33}P. We therefore propose that direct cellular exposure to {sup 33}P-orthophosphate is an excellent means to induce and label the IR-induced, ATM kinase-dependent phosphoproteome.

  16. 17-Beta estradiol and 4-nonylphenol delay smolt development and downstream migration in Atlantic salmon, Salmo salar

    DEFF Research Database (Denmark)

    Madsen, Steffen S; Skovbølling, Søren; Nielsen, Christian;

    2004-01-01

    The effect of 17-beta estradiol (E2) and 4-nonylphenol (4-NP) on smoltification and downstream migration of Atlantic salmon was studied in an integrated laboratory and field study. In a stock of hatchery-raised 1-year-old salmon, smoltification progressed from February until late May as judged by...

  17. Characteristics of a 85Kr beta-particle source applied in Series 1 reference irradiations of TMDIS-1 direct ion storage dosemeters

    International Nuclear Information System (INIS)

    Characteristics necessary to specify an ISO 6980 Series 1 reference radiation field were determined for a commercially available 85Kr beta-particle source, using a BEAM EGS4 Monte Carlo code. The characteristics include residual maximum beta energy, Eres, and the uniformity of the dose rate over the calibration area. The Eres and the uniformity were also determined experimentally, using an extrapolation ionization chamber (EC) and a 0.2 cm3 parallel plate ionization chamber, respectively. The depth-dose curve measured with the EC gave a value 0.62 MeV for the Eres. Series 2 90Sr + 90Y and Series 1 85Kr beta-particle sources calibrated for Hp(0.07) at the secondary standard dosimetry laboratory (SSDL) of STUK were used to determine the energy and angular responses of TMDIS-1 direct ion storage dosemeters. The averaged zero angle Hp(0.07) responses to the 90Sr + 90Y and 85Kr reference radiations were 135 and 80%, respectively. The responses were normalized to 100%, Hp (0.07) response to 137Cs photon radiation. (authors)

  18. Dosimetry of beta particles using Li:Mg, Cu, P + Ptfe; Dosimetria de particulas beta usando Li: Mg, Cu, P + Ptfe

    Energy Technology Data Exchange (ETDEWEB)

    Olvera, L.; Azorin, J.; Rivera, T. [Depto. de Fisica, UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    This paper presents the experimental results of determining the thermoluminescence (Tl) response of LiF: Mg, Cu, P + Ptfe pellets excited with {sup 90}Sr/{sup 90}Y beta radiation. The glow curve exhibited three peaks which appear at 121 C, 178 C and 217 C . Its relative sensitivity is 49 with respect to that of the TLD-100 dosemeter taken as a reference. The minimal dose that could be measured was 750 mGy. The Tl response as a function of dose was linear in the range of 0.7 mGy to 22.5 mGy. The study of the repeatability of the information contained in the pellets showed a standard deviation of 2 %. (Author)

  19. Epoetin beta pegol alleviates oxidative stress and exacerbation of renal damage from iron deposition, thereby delaying CKD progression in progressive glomerulonephritis rats

    OpenAIRE

    Hirata, Michinori; Tashiro, Yoshihito; Aizawa, Ken; Kawasaki, Ryohei; Shimonaka, Yasushi; Endo, Koichi

    2015-01-01

    Abstract The increased deposition of iron in the kidneys that occurs with glomerulopathy hinders the functional and structural recovery of the tubules and promotes progression of chronic kidney disease (CKD). Here, we evaluated whether epoetin beta pegol (continuous erythropoietin receptor activator: CERA), which has a long half‐life in blood and strongly suppresses hepcidin‐25, exerts renoprotection in a rat model of chronic progressive glomerulonephritis (cGN). cGN rats showed elevated urin...

  20. Experimental observation of $\\beta$-delayed neutrons from $^{9}$Li as a way to study short-pulse laser-driven deuteron production

    CERN Document Server

    Favalli, Andrea; Henzlova, Daniela; Falk, Katerina; Croft, Stephen; Gautier, Donald C; Ianakiev, Kiril D; Iliev, Metodi; Palaniyappan, Sasikumar; Roth, Markus; Fernandez, Juan C; Swinhoe, Martyn T

    2016-01-01

    A short-pulse laser-driven deuteron beam is generated in the relativistic transparency regime and aimed at a beryllium converter to generate neutrons at the TRIDENT laser facility. These prompt neutrons have been used for active interrogation to detect nuclear materials, the first such demonstration of a laser-driven neutron source. During the experiments, delayed neutrons from $^9$Li decay was observed. It was identified by its characteristic half-life of 178.3 ms. Production is attributed to the nuclear reactions $^9$Be(d,2p)$^9$Li and $^9$Be(n,p)$^9$Li inside the beryllium converter itself. These reactions have energy thresholds of 18.42 and 14.26 MeV respectively, and we estimate the (d,2p) reaction to be the dominant source of $^9$Li production. Therefore, only the higher-energy portion of the deuteron spectrum contributes to the production of the delayed neutrons. It was observed that the delayed-neutron yield decreases with increasing distance between the converter and the deuteron source. This behavio...

  1. MMAPDNG: A new, fast code backed by a memory-mapped database for simulating delayed γ-ray emission with MCNPX package

    Science.gov (United States)

    Lou, Tak Pui; Ludewigt, Bernhard

    2015-09-01

    The simulation of the emission of beta-delayed gamma rays following nuclear fission and the calculation of time-dependent energy spectra is a computational challenge. The widely used radiation transport code MCNPX includes a delayed gamma-ray routine that is inefficient and not suitable for simulating complex problems. This paper describes the code "MMAPDNG" (Memory-Mapped Delayed Neutron and Gamma), an optimized delayed gamma module written in C, discusses usage and merits of the code, and presents results. The approach is based on storing required Fission Product Yield (FPY) data, decay data, and delayed particle data in a memory-mapped file. When compared to the original delayed gamma-ray code in MCNPX, memory utilization is reduced by two orders of magnitude and the ray sampling is sped up by three orders of magnitude. Other delayed particles such as neutrons and electrons can be implemented in future versions of MMAPDNG code using its existing framework.

  2. Proton and $\\gamma$- partial widths of astrophysically important states of $^{30}$S studied by the $\\beta$-delayed decay of $^{31}$Ar

    CERN Document Server

    Koldste, G T; Borge, M J G; Briz, J A; Carmona-Gallardo, M; Fraile, L M; Fynbo, H O U; Giovinazzo, J; Johansen, J G; Jokinen, A; Jonson, B; Kurturkian-Nieto, T; Kusk, J H; Nilsson, T; Perea, A; Pesudo, V; Picado, E; Riisager, K; Saastamoinen, A; Tengblad, O; Thomas, J -C; Van de Walle, J

    2013-01-01

    Resonances just above the proton threshold in $^{30}$S affect the $^{29}$P(p,$\\gamma$)$^{30}$S reaction under astrophysical conditions. The (p,$\\gamma$)-reaction rate is currently determined indirectly and depends on the properties of the relevant resonances. We present here a method for finding the ratio between the proton and $\\gamma$- partial widths of resonances in $^{30}$S. The widths are determined from the $\\beta$-2p and $\\beta$-p-$\\gamma$- decay of $^{31}$Ar, which is produced at ISOLDE, CERN. Experimental limits on the ratio between the proton and $\\gamma$- partial widths for astrophysical relevant levels in $^{30}$S have been found for the first time. A level at 4689.2(24)keV is identified in the $\\gamma$-spectrum, and an upper limit on the $\\Gamma_{p}/\\Gamma_{\\gamma}$ ratio of 0.26 (95% C.L.) is found. In the two-proton spectrum two levels at 5227(3)keV and 5847(4)keV are identified. These levels were previously seen to $\\gamma$-decay and upper limits on the $\\Gamma_{\\gamma}/\\Gamma_{p}$ ratio of 0....

  3. Forecasting of DST index from auroral electrojet indices using time-delay neural network + particle swarm optimization

    Science.gov (United States)

    Lazzús, J. A.; López-Caraballo, C. H.; Rojas, P.; Salfate, I.; Rivera, M.; Palma-Chilla, L.

    2016-05-01

    In this study, an artificial neural network was optimized with particle swarm algorithm and trained to predict the geomagmetic DST index one hour ahead using the past values of DST and auroral electrojet indices. The results show that the proposed neural network model can be properly trained for predicting of DST(t + 1) with acceptable accuracy, and that the geomagnetic indices used have influential effects on the good training and predicting capabilities of the chosen network.

  4. Attenuation studies of beta particles in glass, PVC, stainless steel for accurate activity estimation of 32P coated to coronary stents

    International Nuclear Information System (INIS)

    Restenosis or closure of the artery due to wound healing is one of the problems in post-coronary intervention, such as angioplasty. Intravascular irradiation with beta particles has shown to prevent restenosis to a good extent. In particular, beta particles emitting radioisotopes such as 32P and 90Sr are ideal for local irradiation as 95% dose in tissues is delivered within 4 mm of the source position. 32P coated stents are in use for intravascular brachytherapy source due to its high dose rate delivery to the exposed tissues. The high radiation dose rate delivered by such intravascular radioactive stent in a short span of implantation is an appealing approach to prevent restenosis by non-selectively killing dividing cells. Radiation dose of the order of 15 to 20 Gy is needed to be delivered to the tissues by the implanted 32P stent of about 150-222 KBq activity for prevention of restenosis. However, the accuracy of the dose delivered to the implanted tissues depends on how accurately the activity of 32P in the stent is measured. The quantification of activity is done by using a teletector prior to dispatch of the stents to hospital. In the present paper, the dose measured with different materials which are used for estimating the 32P leached from radioactive stents and correlated it with the direct measurement done by using teletector is given

  5. Determination of end-of-life-failure fractions of HTGR-fuel particles by postirradiation annealing and beta autoradiography

    International Nuclear Information System (INIS)

    Fission-product contamination of the helium coolant of High-Temperature Gas-Cooled Reactors (HTGR) is strongly influenced by the end-of-life (EOL) failed-particle fraction. Knowledge of the EOL-failure fraction is the basis for model calculations to predict the total fission product release from the reactor core. After disintegration of irradiation fuel rods, fuel particles are placed in individual holes of a graphite tray. During a 5-h heat treatment at 10000C in a helium atmosphere failed particles leak fission products, especially the volatile cesium, into the graphite. After unloading a β-autoradiograph of the tray is made. Holes that housed defective particles are identified from black spots on the β-sensitive film. The EOL-failure fraction is the ratio of defective particles to the total number of particles tested. The technique is called PIAA, PostIrradiation Annealing and Autoradiography. The PIAA technique was applied to particles of a Trisocoated highly-enriched UO2 fissile batch irradiated to a burnup of 35% FIMA at an irradiation temperature of 12500C. Visual examination showed all particles to be intact. From 11 to 47% of the particles had failed, as determined by PIAA. Further, postirradiation examination showed that localized corrosion of the silicon carbide coating by fission-product rare-earth chlorides had occurred

  6. Study of neutron-rich $^{51−53}$ Ca isotopes via $\\beta$-decay

    CERN Multimedia

    The high Q-$\\beta$ values in certain neutron-rich regions of the chart of nuclides opens up the possibility to study states in the daughter nuclei which lie at high excitation energy, above the neutron separation threshold. We propose to perform spectroscopy of the $\\beta$-delayed neutron emission of the $^{51-53}$K isotopes to study the population of single-particle or particle-hole states both below and above the neutron separation threshold. The VANDLE neutron detector will be used in combination with the IDS tape station setup and Ge detectors.

  7. Development of new techniques for three dimensional tracking of charged particles for possible applications in the search for neutrinoless double beta decay

    International Nuclear Information System (INIS)

    Since its prediction in 1937, several generations of experimental physicists have tried to confirm the neutrinoless double beta decay. An observation would have fundamental consequences for the understanding of particle physics. However, the experimental requirements are very demanding wherefore the race is still ongoing between many collaborations. The main challenge in this field is the reduction of background. Any decay in the natural decay chain is orders of magnitude more likely than the neutrinoless double beta decay. The half-life of this decay is known to be longer than 1025 years. Therefore, any detector will see a vast majority of events which are not signal events. Such events have to be identified and rejected. Primarily, this is done by measuring the kinetic energy of the decay products but also the trajectory of the particles resulting from the decay can be used for identification. Within the scope of this thesis different techniques were developed and tested which can be used to record such trajectories. It was shown that trajectories can be used indeed to identify and distinguish different types of events. The hybrid semiconductor detector named Timepix was used to record two-dimensional tracks of Compton-scattered electrons and electron-positron pairs in a 1mm thick cadmium-telluride sensor layer. Artificial neural networks could successfully be employed to distinguish both event types. Furthermore, a ''proof-of-principle'' experiment was successfully performed where three dimensional trajectories of high energetic electrons could be reconstructed from data recorded with a similar Timepix detector. Also, a new concept, where three dimensional trajectories of ionizing particles are imaged by scintillation light, was developed and successfully tested. In a ''proof-of-principle'' experiment three dimensional trajectories of high energetic electrons through a scintillator were reconstructed from data taken with a

  8. Beta particle detection efficiency of the radiation sensor made from a mixture of polyaniline and titanium oxide

    Science.gov (United States)

    Tamura, M.; Miyata, H.; Katsumata, M.; Matsuda, K.; Ueno, T.; Ito, D.; Suzuki, T.

    2016-08-01

    We developed a new real-time radiation sensor using an organic semiconductor and measured its β-particle detection sensitivity. This sensor is fabricated by simply combining a p-type semiconductor, polyaniline (Pani), with an n-type semiconductor, TiO2, and processing the compound. Since Pani and TiO2 are both inexpensive materials, the sensor can be fabricated at a lower cost than inorganic semiconductor sensors. The signal of each fabricated sensor was measured by a charge sensitive ADC for the irradiation of β-particles. The response signal data of the ADC for each irradiation was measured to calculate the detection efficiency of the detector. The maximum detection efficiency measured as β-particle sensitivity of the sensor was 1%. This β-particle sensitivity is higher than that reported of Pani sensors in the past.

  9. Effects of anisotropic fluences and angular depended spectra of beta-particles in the use of large area reference sources

    International Nuclear Information System (INIS)

    Calibrations of instrument efficiency of surface contamination meters are usually made with extended reference sources which are standardized in terms of 2π surface β-particle emission rates from the source surface including backscattered particles. Extended sources supplied from various metrology institutes or calibration laboratories, but the source-types such as structure, preparation method, backing and covering materials vary between manufacturers. In this work first we show how the calibration results are dependent on the source type. Second, in order to clarify the possible reason of such discrepancy, we examined the isotropy of β-particle fluences by the use of a proportional counter and also observed the angular dependence of β-particle spectra by the use of small plastic scintillation spectrometer, where the source mount can rotate relative to the detector window at various obliquities. The discrepancy in the instrument-calibration of surface contamination meters, which are mainly used under the conditions of large source-to-detector geometry, can be explained. - Highlights: ► We show how the calibration results are dependent on the source type. ► We examined the isotropy of β-particle fluences and observed the angular dependence. ► Discrepancy of instrument efficiencies using different type of sources is explained.

  10. Thermoluminescent response of LiF : Mg,Cu,P+PTFE prepared in Mexico to 90Sr/90Y beta particles

    International Nuclear Information System (INIS)

    Results of study of the thermoluminescent response of LiF : Mg,Cu,P+PTFE irradiated with beta particles are presented and compared with results for LiF TLD-100. Both materials exhibited a linear dose response in the range from 4.35 mGy to 2.17519 Gy. The glow curve of LiF : Mg,Cu,P+PTFE exhibited four peaks while TLD-100 showed six. All the peaks studied for the two materials exhibited first order kinetics. The average values of activation energy were: 1.35, 1.58 and 2.51 eV for LiF : Mg,Cu,P+PTFE; and, 2.04, 2.24, 2.51 and 2.89 eV for LiF TLD-100. (author)

  11. OSL and TL in LiF:Mg,Ti following alpha particle and beta ray irradiation: Application to mixed-field radiation dosimetry

    International Nuclear Information System (INIS)

    The optically stimulated luminescence (OSL) of LiF:Mg,Ti (TLD-100) following irradiation by beta and alpha particles was investigated by the measurement of the excitation and emission spectra of OSL and comparison with thermoluminescence (TL) characteristics. Measurements were also carried out on nominally pure LiF monocrystals. The preferential excitation of OSL compared to TL following high-ionisation density (HID) alpha irradiation is naturally explained via the identification of OSL with the 'two-hit' F2 or F3+ centre, whereas the major component of composite TL glow peak 5 is believed to arise from a 'one-hit' complex defect. This discovery allows near-total discrimination between HID radiation and low-ionisation density radiation and may have significant potential in mixed-field radiation dosimetry. (authors)

  12. Effects of anisotropic fluences and angular depended spectra of beta-particles in the use of large area reference sources.

    Science.gov (United States)

    Yamada, Takahiro; Kawada, Yasushi; Ishizu, Hidetake; Yamamoto, Shinich; Yunoki, Akira; Sato, Yasushi; Unno, Yasuhiro; Hino, Yoshio

    2012-09-01

    Calibrations of instrument efficiency of surface contamination meters are usually made with extended reference sources which are standardized in terms of 2π surface β-particle emission rates from the source surface including backscattered particles. Extended sources supplied from various metrology institutes or calibration laboratories, but the source-types such as structure, preparation method, backing and covering materials vary between manufacturers. In this work first we show how the calibration results are dependent on the source type. Second, in order to clarify the possible reason of such discrepancy, we examined the isotropy of β-particle fluences by the use of a proportional counter and also observed the angular dependence of β-particle spectra by the use of small plastic scintillation spectrometer, where the source mount can rotate relative to the detector window at various obliquities. The discrepancy in the instrument-calibration of surface contamination meters, which are mainly used under the conditions of large source-to-detector geometry, can be explained. PMID:22424745

  13. Beta Thalassemia

    Science.gov (United States)

    ... South Asian (Indian, Pakistani, etc.), Southeast Asian and Chinese descent. 1 Beta Thalassemia ßß Normal beta globin ... then there is a 25% chance with each pregnancy that their child will inherit two abnormal beta ...

  14. Double beta and dark matter search-window to new physics beyond the Standard Model of particle physics

    International Nuclear Information System (INIS)

    Nuclear double beta decay provides an extraordinarily broad potential to search beyond Standard Model physics, probing already now the TeV scale, on which new physics should manifest itself. These possibilities are reviewed here. First, the results of present generation experiments are presented. The most sensitive one of them - the Heidelberg-Moscow experiment in the Gran Sasso - probes the electron mass now in the sub eV region and will reach a limit of ∼ 0.1 eV in a few years. Basing to a large extend on the theoretical work of the Heidelberg Double Beta Group in the last two years, results are obtained also for SUSY models (R-parity breaking, sneutrino mass), leptoquarks (leptoquark-Higgs coupling), compositeness, right-handed W boson mass, test of special relativity and equivalence principle in the neutrino sector and others. These results are comfortably competitive to corresponding results from high-energy accelerators like TEVATRON, HERA, etc. One of the enriched 76 Ge detectors also yields the most stringent limits for cold dark matter (WIMPs) to date by using raw data. Second, future perspectives of ββ research are discussed. A new Heidelberg experimental proposal (GENIUS) is described which would allow to increase the sensitivity for Majorana neutrino masses from the present level at best 0.1 eV down to 0.01 eV or even 0.001 eV. Its physical potential would be a breakthrough into the multi-TeV range for many beyond standard models. Its sensitivity for neutrino oscillation parameters would be larger than of all present terrestrial neutrino oscillation experiments and of those planned for the future. It could probe directly the atmospheric neutrino problem and the large angle, and for almost degenerate neutrino mass scenarios even the small angle solution of the solar neutrino problem. It would further, already in a first step using only 100 kg of natural Ge detectors, cover almost the full MSSM parameter space for prediction of neutralinos as cold

  15. Beta Androstenediol Mitigates the Damage of 1 GeV/n Fe Ion Particle Radiation to the Hematopoietic System

    OpenAIRE

    Loria, Roger; Beckman, Mathew; Contaifer, Daniel; Tamariz, Francisco; Gibb, David; Thompson, Laura; Guida, Peter

    2011-01-01

    Space exploration is associated with exposure to 1–3 Gy solar particle radiation and galactic cosmic radiation that could increase cancer rates. Effective nontoxic countermeasures to high linear energy transfer (LET) radiation exposure are highly desirable but currently not available. The aim was to determine whether a single subcutaneous injection of androstenediol (Δ5 androsten-3β, 17β-diol [AED]) could mitigate and restore the mouse hematopoetic system from the radiation-mediated injury of...

  16. Low-beta structures

    OpenAIRE

    M. Vretenar(CERN, Geneva, Switzerland)

    2012-01-01

    'Low-beta' radio-frequency accelerating structures are used in the sections of a linear accelerator where the velocity of the particle beam increases with energy. The requirement for space periodicity to match the increasing particle velocity led to the development of a large variety of structures, both normal and superconducting, which are described in this lecture.

  17. Search for Long-Lived Neutral Particles in Final states with Delayed Photon and Missing Transverse Energy from Proton-Proton Collisions using the CMS detector

    CERN Document Server

    AUTHOR|(CDS)2080019; Kubota, Yuichi; Kao, Shih-Chuan; Kubota, Yuichi

    2016-12-01

    We perform a search for long-lived neutral particles in final state with delayed photons and large missing transverse energy produced in LHC proton-proton collisions at center-of-mass energy, $\\sqrt{s} = 8\\TeV$. Capitalizing on the excellent timing resolution of the CMS Electromagnetic Calorimeter the search uses photon time measurements made by the Electromagnetic Calorimeter as the main search quantity. We found a single event consistent with our background expectations from the Standard Model and set a model-independent upper limit of 4.37 on number of signal events. We also interpret our results in the context of the SPS8 benchmark GMSB model and show that neutralinos with mean lifetime, $\\tau \\leq 45$ns, and mass, $m \\leq 300\\GeV/c^{2}$, or effective Supersymmetry breaking energy scale, $\\Lambda \\leq 220\\TeV$, are ruled out of existence at 95% $CL_{S}$ confidence level. The exclusion limit on the product of the production cross-section and branching ratio of the neutralino to photon and gravitino decay ...

  18. A primary standard for the measurement of alpha and beta particle surface emission rate from large area reference sources.

    Science.gov (United States)

    Ravindra, Anuradha; Kulkarni, D B; Joseph, Leena; Kulkarni, M S; Babu, D A R

    2016-01-01

    A large area windowless gas flow multi wire proportional counting system for the calibration of large area reference sources has been developed as a primary standard at Bhabha Atomic Research Centre (BARC). The counting system consists of a multi wire proportional counter (MWPC), vacuum system, gas flow system and pulse processing units. The MWPC detector assembly consists of a vacuum tight aluminum enclosure, multi wire grid and sliding source tray. Various detector characteristics like operating characteristics curve, Fe-55 spectrum for beta discriminator threshold setting and dead time of the measurement system were studied and determined in order to achieve an optimized detection capability. The surface emission rates of different source strengths were measured and their relative combined standard uncertainties were determined. Large Area Sources Comparison Exercise (LASCE) was organized by International Committee on Radionuclide Metrology (ICRM) working group and coordinated by National Institute for Ionising Radiation Metrology (ENEA), Italy, to demonstrate equivalence of surface emission rate measurements at the international platform. BARC participated in the programme and the results of LASCE are also discussed in this paper. PMID:26457924

  19. Majorana neutrino. Is double neutrinoless beta decay possible in the framework of the weak interactions? How to prove that neutrino is a Majorana particle?

    International Nuclear Information System (INIS)

    Usually it is supposed that Majorana neutrino is produced in the superposition state χL=νL+(νL)c and then follows the neutrinoless double beta decay. But since weak interactions are chiral-invariant, the neutrino at production has definite helicity (i.e., νL and (νL)c neutrinos are separately produced and then neutrino is not in the superposition state). This helicity cannot change after production without any external interactions. Thus, we see that for unsuitable helicity the neutrinoless double β decay is not possible even if neutrino is a Majorana particle. Also transition of Majorana neutrino into antineutrino at their oscillations is forbidden since helicity in vacuum holds. Then the only possibility to prove that neutrino is a Dirac but not Majorana particle is detection of transition of νL neutrino into (sterile) antineutrino νR bar (i.e., νL→νR bar) at neutrino oscillations. Transition of Majorana neutrino νL into (νR)c (i.e., νL→(νR)c) at oscillations is unobserved since it is supposed that the mass of (νR)c is very big

  20. Determination of Li, B, and F by rapid instrumental neutron activation analysis using beta-particle counting

    International Nuclear Information System (INIS)

    For the simultaneous determination of Li, B, and F, the application of rapid instrument neutron activation analysis was studied using 1.5s of irradiation and β-particle counting of 8Li, 12B, and 20F. The fast transfer facility, Mach-1, the counting equipment, a 4-channel multiplexer, and a time-base controller are discussed. Further, the technique of simultaneous decay curve analysis of three successive decays is presented and quality control by residual analysis is demonstrated. Finally, analytical results are presented of the NBS-environmental standards Coal-1632a and Coal-1635, and of three BCR-coals intended as references materials

  1. Nanoscale size dependence in the conjugation of amyloid beta and ovalbumin proteins on the surface of gold colloidal particles

    International Nuclear Information System (INIS)

    Absorption spectroscopy was utilized to investigate the conjugation of amyloid β protein solution (Aβ1-40) and chicken egg albumin (ovalbumin) with various sizes of gold colloidal nanoparticles for various pHs, ranging from pH 2 to pH 10. The pH value that indicates the colour change, pHo, exhibited colloidal size dependence for both Aβ1-40 and ovalbumin coated particles. In particular, Aβ1-40 coated gold colloidal particles exhibited non-continuous size dependence peaking at 40 and 80 nm, implying that their corresponding cage-like structures provide efficient net charge cancellation at these core sizes. Remarkably, only the pHo value for ovalbumin coated 80 nm gold colloid was pH>7, and a specific cage-like structure is speculated to have a positive net charge facing outward when ovalbumin self-assembles over this particular gold colloid. The previously reported reversible colour change between pH 4 and 10 took place only with Aβ1-40 coated 20 nm gold colloids; this was also explored with ovalbumin coated gold colloids. Interestingly, gold colloidal nanoparticles showed a quasi-reversible colour change when they were coated with ovalbumin for all test sizes. The ovalbumin coated gold colloid was found to maintain reversible properties longer than Aβ1-40 coated gold colloid

  2. Double beta decay to the first 2+ state within a boson expansion formalism with a projected spherical single particle basis

    International Nuclear Information System (INIS)

    The Gamow-Teller transition operator is written as a polynomial in the dipole proton-neutron and quadrupole charge conserving QRPA boson operators, using the prescription of the boson expansion technique of Belyaev-Zelevinski type. Then, the 2νββ process ending on the first 2+ state in the daughter nucleus is allowed via one, two and three boson states describing the odd-odd intermediate nucleus. The approach uses a single particle basis which is obtained by projecting out the good angular momentum from an orthogonal set of deformed functions. The bases for mother and daughter nuclei have different deformations. The GT transition amplitude as well as the half lives was calculated for eleven transitions. Results are compared with the available data as well as with some predictions obtained with other methods

  3. Beta androstenediol mitigates the damage of 1 GeV/n Fe ion particle radiation to the hematopoietic system.

    Science.gov (United States)

    Loria, Roger; Beckman, Mathew; Contaifer, Daniel; Tamariz, Francisco; Gibb, David; Thompson, Laura; Guida, Peter

    2011-08-01

    Space exploration is associated with exposure to 1-3 Gy solar particle radiation and galactic cosmic radiation that could increase cancer rates. Effective nontoxic countermeasures to high linear energy transfer (LET) radiation exposure are highly desirable but currently not available. The aim was to determine whether a single subcutaneous injection of androstenediol (Δ(5) androsten-3β, 17β-diol [AED]) could mitigate and restore the mouse hematopoetic system from the radiation-mediated injury of 3 Gy whole-body high LET (56)Fe(26+) exposure. The findings show that postradiation AED treatment has an overall positive and significant beneficial effect to restore the levels of hematopoeitic elements (pcell, hemoglobin, and platelet counts. Flow cytometry analysis 14 days after radiation and AED treatment demonstrated an increase (pcells counts. Ex vivo osteoclastogenesis studies show that AED treatment is necessary and advantageous for the development and restoration of osteoclastogenesis after radiation exposure. These findings clearly show that androstenediol functions as a countermeasure to remedy hematopoeitic injury mediated by high LET iron ion radiation. Presently, no other agent has been shown to have such properties. PMID:21790310

  4. Photochemical reactions in dehydrated photosynthetic organisms, leaves, chloroplasts and photosystem II particles: reversible reduction of pheophytin and chlorophyll and oxidation of {beta}-carotene

    Energy Technology Data Exchange (ETDEWEB)

    Shuvalov, Vladimir A.; Heber, Ulrich

    2003-11-01

    Photoreactions of dehydrated leaves, isolated broken chloroplasts and PSII membrane fragments of spinach (Spinacia oleracea) were studied at different air humidities and compared with photoreactions of dry fronds of a fern, Polypodium vulgare, and a dry lichen, Parmelia sulcata, which in contrast to spinach are insensitive to photoinactivation in the dry state. Even in very dry air, P700 in the reaction center of photosystem I of dry leaves was oxidized, and the primary quinone acceptor Q{sub A} in the reaction center of photosystem II was photoreduced by low light. These reactions were only very slowly reversed in the dark and saturated under low light intensity. Light-minus-dark difference absorption spectra of the dry leaves, isolated chloroplasts and PSII membrane fragments measured at higher light intensities revealed absorbance changes of {beta}-carotene at 500 nm (light-dependent bleaching) and 980 nm (light-dependent band formation) and bleaching of chlorophyll at 436 and 680 nm with appearance of bands at 450 and 800 nm. Decrease of chlorophyll fluorescence upon strong illumination indicated photoaccumulation of a quencher. All these changes were kinetically related and readily reversible. They are interpreted to show light-induced oxidation of {beta}-carotene (Car) and reduction of chlorophyll-680 (Chl-680) in the reaction center of photosystem II of the dried leaves, chloroplasts and photosystem II particles. The fluorescence quencher was suggested to be Chl-680{sup -} or Car{sup +} in close proximity to P680, the primary electron donor. Appreciable photoaccumulation of reduced pheophytin was only observed in dry leaves after Q{sub A} reduction had been lost during heat treatment of hydrated leaves prior to dehydration. The observations are interpreted to show light-dependent cyclic electron flow within the reaction center of photosystem II in which Chl-680 (or Pheo) is reduced by P680* and Car is oxidized by P680{sup +} with consequent recombination of

  5. Delayed discharge.

    Science.gov (United States)

    Allen, Daniel

    2016-07-01

    Essential facts Delays in discharging older peo ple from hospital cost the NHS £820 million a year, according to a report from the National Audit Office (NAO). Last year in acute hospitals, 1.15 million bed days were lost to delayed transfers of care, an increase of 31% since 2013. The NAO says rising demand for NHS services is compounded by reduced local authority spending on adult social care - down by 10% since 2009-10. PMID:27380673

  6. Developments for a measurement of the beta -- nu correlation and determination of the recoil charge-state distribution in 6He beta decay

    Science.gov (United States)

    Hong, Ran

    The beta-nu of a pure Gamow-Teller beta decay such as the 6He decay is sensitive to tensor-type weak currents predicted by theories beyond the Standard Model. An experiment is developed at University of Washington aiming at measuring the coefficient a_{beta-nu} of 6He decays to the 0.1% level and looking for its deviation from the Standard-Model prediction -1/3 using laser-trapped 6He atoms. The beta particle is detected by a scintillator and a multi-wire proportional chamber, and the recoil ion is detected by a microchannel plate with delay-line anodes for position readouts. a_{beta-nu} is extracted by fitting the measured time-of-flight spectrum of the recoil ions to templates generated by Monte Carlo simulations. This dissertation describes the developments of this experiment for the intermediate goal of a 1% level a_{beta-nu} measurement, such as the detector design, Monte Carlo simulation software, and data analysis frame work. Particularly, detector calibrations are described in detail. The analysis of a 2% level proof-of-principle run in October 2015 is presented as well. Shake-off probabilities for decays of trapped 6He atoms matter for the high-precision a_{beta-nu} measurement. The charge state distribution of recoil ions is obtained by analyzing their time-of-flight distribution using the same experimental setups for the a_{beta-nu} measurement. An analysis approach that is independent of the beta-nu correlation is developed. The measured upper limit of the double shake-off probability is 2x10. {-4} at 90% confidence level. This result is 100 times lower than the most recent calculation by Schulhoff and Drake. This disagreement is significant for the a_{beta-nu} measurement and needs to be addressed by improved atomic theory calculations.

  7. Neutrinoless Double Beta Decay

    CERN Document Server

    Päs, Heinrich

    2015-01-01

    We review the potential to probe new physics with neutrinoless double beta decay $(A,Z) \\to (A,Z+2) + 2 e^-$. Both the standard long-range light neutrino mechanism as well as short-range mechanisms mediated by heavy particles are discussed. We also stress aspects of the connection to lepton number violation at colliders and the implications for baryogenesis.

  8. A quantum delayed choice experiment

    OpenAIRE

    Peruzzo A.; Shadbolt P.; Brunner N.; Popescu S.; O'Brien J.L.

    2012-01-01

    Quantum systems exhibit particle-like or wave-like behaviour depending on the experimental apparatus they are confronted by. This wave-particle duality is at the heart of quantum mechanics, and is fully captured in Wheeler's famous delayed choice gedanken experiment. In this variant of the double slit experiment, the observer chooses to test either the particle or wave nature of a photon after it has passed through the slits. Here we report on a quantum delayed choice experiment, based on a q...

  9. How well do we know the beta-decay of 16N and oxygen formation in helium burning?

    International Nuclear Information System (INIS)

    We review the status of the 12C(α, γ)16O reaction rate, of importance for stellar processes in a progenitor star prior to a supernova collapse. Several attempts to constrain the p-wave S-factor of the 12C(α, γ)16O reaction at Helium burning temperatures (200 MK) using the beta-delayed alpha-particle emission of 16N have been made, and it is claimed that this S-factor is known, as quoted by the TRIUMF collaboration. In contrast, reanalyses (by GM Hale) of all thus far available data (including the 16N data) does not rule out a small S-factor solution. Furthermore, we improved our previous Yale-UConn study of the beta-delayed alpha-particle emission of 16N by improving our statistical sample (by more than a factor of 5), improving the energy resolution of the experiment (by 20%), and in understanding our line shape, deduced from measured quantities. Our newly measured spectrum of the beta-delayed alpha-particle emission of 16N is not consistent with the TRIUMF (1994) data, but is consistent with the Seattle (1995) data, as well as the earlier (unaltered) data of Mainz (1971). The implication of these discrepancies for the extracted astrophysical p-wave S-factor is briefly discussed. (author)

  10. Delayed privatization

    OpenAIRE

    Bernardo Bortolotti; Paolo Pinotti

    2008-01-01

    This paper studies the timing of privatization in 21 major developed economies in the 1977-2002 period. Duration analysis shows that political fragmentation plays a significant role in explaining government's decision to privatize: privatization is delayed longer in democracies characterized by a larger number of parties and operating under proportional electoral rules, as predicted by war of attrition models of economic reform. Results are robust to various assumptions on the underlying stat...

  11. A semiconductor beta ray spectrometer

    International Nuclear Information System (INIS)

    Measurement of energy spectra of beta particles emitted from nuclei in beta-decay processes provides information concerning the mass difference of these nuclei between initial and final state. Moreover, experimental beta spectra yield information on the feeding of the levels in the daughter nucleus. Such data are valuable in the construction and checking of the level schemes. This thesis describes the design, construction, testing and usage of a detector for the accurate measurement of the mentioned spectra. In ch. 2 the design and construction of the beta spectrometer, which uses a hyper-pure germanium crystal for energy determination, is described. A simple wire chamber is used to discriminate beta particles from gamma radiation. Disadvantages arise from the large amounts of scattered beta particles deforming the continua. A method is described to minimize the scattering. In ch. 3 some theoretical aspects of data analysis are described and the results of Monte-Carlo simulations of the summation of annihilation radiation are compared with experiments. Ch. 4 comprises the results of the measurements of the beta decay energies of 103-108In. 87 refs.; 34 figs.; 7 tabs

  12. Thermoluminescent characteristics (TL) of K2F5: Y0.99 Tb0.01 irradiated with beta particles of 90Sr/90 Y

    International Nuclear Information System (INIS)

    In this work the results of studying the thermoluminescent characteristics of the K2F5: Y0.99 Tb0.01 are presented. The material was characterized irradiating samples of K2F5: Y0.99Tb0.01 in powder with beta radiation of 90Sr/90Y. The studied characteristics were TL curve, response reproducibility, TL response in function of the dose and fading of the information. The samples exhibited a thermoluminescent curve (TL) with two very defined peaks centered respectively in 167 and 307 C. The TL response of the samples under the action of the beta radiation after 10 cycles (thermal erased, irradiation and reading of the samples) presented a standard deviation of 3.09%. The TL response of K2F5: Y0.99 Tb0.01 in function of the absorbed dose of beta radiation resulted lineal in the interval of 3 mGy to 1.29 Gy. The fading of the information contained in the samples of K2F5: Y0.99 Tb0.01 was of 40% in the first 10 minutes, which is due to the first peak. The obtained results suggest that the TL material resulted as promissory for its possible use as thermoluminescent dosemeter of beta radiation using the second peak of its TL curve like dosimetric peak. (Author)

  13. Single-Particle States in $^{133}$Sn

    CERN Document Server

    Huck, A

    2002-01-01

    % IS338 \\\\ \\\\ It is suggested to investigate the $\\beta^- $-decay of $^{133}$In and $^{134}$In in order to determine the single-particle states in $^{133}$Sn, which are so far unknown and needed for the shell-model description of the region close to $^{132}$Sn. Large hyper-pure Ge-detectors will be used for the $\\gamma$-ray spectroscopy. In the experiments with $^{134}$In, delayed neutrons in coincidence with $\\gamma$-rays from excited states in $^{133}$Sn provide the opportunity for a very selective detection of the states in question.

  14. Design flaw could delay collider

    CERN Multimedia

    Cho, Adrian

    2007-01-01

    "A magnet for the Large Hadron Collider (LHC) failed during a key test at the European particle physics laboratory CERN last week. Physicists and engineers will have to repair the damaged magnet and retrofit others to correct the underlynig design flaw, which could delay the start-up of the mammouth subterranean machine." (1,5 page)

  15. Synthesis and thermoluminescent characterization of new matches of LiF:Eu exposed to beta particles; Sintesis y caracterizacion termoluminiscente de nuevos fosforos de LiF:Eu expuestos a particulas beta

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval G, L. M.; Garcia H, A. R. [Universidad de Sonora, Departamento de Ciencias Quimico Biologicas, 83000 Hermosillo, Sonora (Mexico); Bernal, R. [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico); Cruz V, C.; Burruel I, S. E. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Castano, V. M., E-mail: a211200753@alumnos.uson.mx [UNAM, Instituto de Fisica, Departamento de Fisica Aplicada y Tecnologia Avanzada, Apdo. Postal 1-1010, 76000 Queretaro, Qro. (Mexico)

    2015-10-15

    Full text: LiF has been and currently is a base material in the preparation of commercial dosimeters due to its characteristics and dosimetric properties. Obtain a material that has stable and sensitive characteristics is what is sought in the field of dosimetry. Pellets were manufactured with different concentrations of dopant (EuCl{sub 3}) ranging between 0.5, 1.0, 1.5% mol, using the coprecipitation method, these pellets were synthesized at 750 degrees C for 5 hours. The concentration of dopant with the best characteristics is 1.5% mol of EuCl{sub 3}. During the thermoluminescent characterization, the pellets were subjected to various doses of beta radiation ranging from 0.5 to 2.5 Gy, yielding glow curves that increase the intensity of the Tl signal with increasing radiation dose. The results also show good reproducibility, with a main peak around 250 degrees C and a low fading of thermoluminescent signal. (Author)

  16. A comparison of intravascular source designs based on the beta particle emitter 114mIn/114In Line source versus stepping source

    International Nuclear Information System (INIS)

    Background: Catheter-based intravascular brachytherapy (IVB) sources of the next generation will have to meet high demands in terms of miniaturization, flexibility, safety, reliability, costs and versatility. The radionuclide pair 114mIn/114In (half-life 49.51 days, maximum beta energy 2.0 MeV, average beta energy 0.78 MeV) is an attractive beta emitter for application in such a source. Methods: Since metallic indium is unfit for the manufacture of a brachytherapy source, the feasibility, safety and dosimetric properties of a design concept comprising a linear array of ceramic In2O3 spheres within a thin-walled, superelastic Ni/Ti capsule are investigated. Results: Neutron activation of enriched In2O3 spheres yields a specific activity sufficiently high for the manufacture of a stepping source, keeping treatment times limited to a few minutes. Although 114mIn/114In also emits some gamma radiation, the effective doses received by members of the medical staff are an order of magnitude lower than those received from fluoroscopy. The dose distributions about a 40-mm line source and a 5-mm stepping source (outer diameter 0.36 mm) are calculated using MCNP4C. Dose-volume histograms (DVHs) are calculated for the line source (centered and noncentered) and the stepping source (centered) using the geometry of a human coronary artery. Conclusion: The results show that a centered stepping source with optimized dwell times delivers the most homogenous dose within the target volume

  17. Observation of the delayed proton decay by means of a recoil mass separator

    International Nuclear Information System (INIS)

    The report addresses the observation of the beta-delayed proton decay of Tz=-2 nuclei by using a recoil mass separator. Development of a measuring technique and results obtained so far are described. Various improvements are made in the recoil mass separator to solve major problems arising from the fact that the cross section of the (3He, 3N) reaction is small. The improvements are mostly intended for increased yield and S/N ratio. To increase the yield, a special optical system is developed for the recoil mass separator and analysis is made of the cycle of beam switching and the inclination of the target. The optical system developed has a detecting solid angle of 3msr and an energy receiving width of ±10 percent. To increase the S/N ratio, an ion-passing detector is developed and analysis is made of the times and positions of ion events and decay particle events by means of the combination of the ion-passing detector and a position-sensitive detector. A beta counter is used in combination to decrease the background. The report also presents some data on the energy spectrum of beta-delayed protons from 25Si, 24Si and 17Ne. (N.K.)

  18. A quantum delayed choice experiment

    CERN Document Server

    Peruzzo, Alberto; Brunner, Nicolas; Popescu, Sandu; O'Brien, Jeremy L

    2012-01-01

    Quantum systems exhibit particle-like or wave-like behaviour depending on the experimental apparatus they are confronted by. This wave-particle duality is at the heart of quantum mechanics, and is fully captured in Wheeler's famous delayed choice gedanken experiment. In this variant of the double slit experiment, the observer chooses to test either the particle or wave nature of a photon after it has passed through the slits. Here we report on a quantum delayed choice experiment, based on a quantum controlled beam-splitter, in which both particle and wave behaviours can be investigated simultaneously. The genuinely quantum nature of the photon's behaviour is tested via a Bell inequality, which here replaces the delayed choice of the observer. We observe strong Bell inequality violations, thus showing that no model in which the photon knows in advance what type of experiment it will be confronted by, hence behaving either as a particle or as wave, can account for the experimental data.

  19. Beta and muon decays

    International Nuclear Information System (INIS)

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  20. $^{11}$Be($\\beta$p), a quasi-free neutron decay?

    CERN Document Server

    Riisager, K.; Borge, M.J.G.; Briz, J.A.; Carmona-Gallardo, M.; Fraile, L.M.; Fynbo, H.O.U.; Giles, T.; Gottberg, A.; Heinz, A.; Johansen, J.G.; Jonson, B.; Kurcewicz, J.; Lund, M.V.; Nilsson, T.; Nyman, G.; Rapisarda, E.; Steier, P.; Tengblad, O.; Thies, R.; Winkler, S.R.

    2014-01-01

    We have observed $\\beta$-delayed proton emission from the neutron-rich nucleus $^{11}$Be by analysing a sample collected at the ISOLDE facility at CERN with accelerator mass spectrometry (AMS). With a branching ratio of (8.4 $\\pm$ 0.6)$\\times$ 10$^{-6}$ the strength of this decay mode, as measured by the B$_\\mathrm{GT}$-value, is unexpectedly high. The result is discussed within a simple single-particle model and could be interpreted as a quasi-free decay of the $^{11}$Be halo neutron into a single-proton state.

  1. Targeted Cancer Therapy with a Novel Anti-CD37 Beta-Particle Emitting Radioimmunoconjugate for Treatment of Non-Hodgkin Lymphoma

    OpenAIRE

    Repetto-Llamazares, Ada H V; Larsen, Roy H.; Sebastian Patzke; Fleten, Karianne G; David Didierlaurent; Alexandre Pichard; Jean Pierre Pouget; Jostein Dahle

    2015-01-01

    177Lu-DOTA-HH1 (177Lu-HH1) is a novel anti-CD37 radioimmunoconjugate developed to treat non-Hodgkin lymphoma. Mice with subcutaneous Ramos xenografts were treated with different activities of 177Lu-HH1, 177Lu-DOTA-rituximab (177Lu-rituximab) and non-specific 177Lu-DOTA-IgG1 (177Lu-IgG1) and therapeutic effect and toxicity of the treatment were monitored. Significant tumor growth delay and increased survival of mice were observed in mice treated with 530 MBq/kg 177Lu-HH1 as compared with mice ...

  2. Time delay in quantum scattering

    International Nuclear Information System (INIS)

    As is well known, the knowledge of the scattering cross section and its angular dependence, as a function of energy, is insufficient to determine the phase shifts uniquely. This led Eisenbud and Wigner to propose the measurement of the scattering lifetime or time delay as an additional independent datum. A rigorous time-dependent study of time delay within the framework of Hilbert space formalism is presented. Specifically, Martin's theory of time delay and the validity of the Eisenbud-Wigner time delay formula are extended to spherically symmetric potentials satisfying the asymptotic fall-off rate V(r) → O(r/sup -2-epsilon/). This extension is obtained by use of a maximal estimate of the rate of convergence of the asymptotic condition and the elimination of Martin's requirement that the scattering operator S be three times differentiable with respect to the free-particle Hamiltonian H0. Also presented are related results on the total time a quantum particle spends inside some bounded regions in position space. It is then proved that any two free particles having identical distributions of energy and angular momentum take exactly identical expectation values for the transit time across an arbitrary spherical region centered at the origin in position space. Ways to extend this result to nonfree Hamiltonians are indicated. Finally, the relationship between the position operator and the Eisenbud-Wigner time delay operator is examined. It is shown that the usual method of calculating time delay based on the classical analysis of the position operator is not exact

  3. $\\beta$-decay study of neutron-rich Tl and Pb isotopes

    CERN Multimedia

    It is proposed to study the structure of neutron-rich nuclei beyond $^{208}$Pb. The one-proton hole $^{211-215}$Tl and the semi magic $^{213}$Pb will be produced and studied via nuclear and atomic spectroscopy searching for long-lived isomers and investigating the $\\beta$-delayed $\\gamma$- emission to build level schemes. Information on the single particle structure in $^{211-215}$Pb, especially the position of the g$_{9/2}$ and i$_{11/2}$ neutron orbitals, will be extracted along with lifetimes. The $\\beta$-decay will be complemented with the higher spin selectivity that can be obtained by resonant laser ionization to single-out the decay properties of long-living isomers in $^{211,213}$Tl and $^{213}$Pb.

  4. Dynamic radioactive particle source

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E.; Gauss, Adam Benjamin; Justus, Alan Lawrence

    2012-06-26

    A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

  5. Bremsstrahlung in Mo and Pt targets produced by 90Sr beta particles in the photon energy region of 1-100 keV

    International Nuclear Information System (INIS)

    Bremsstrahlung spectra in thick targets of Mo and Pt, produced by beta emitter 90Sr (end point energy = 546 keV) have been studied in the photon energy range of 1-100 keV. The experimentally measured bremsstrahlung spectra measured with Si(Li) detector were compared with the theoretical spectral distributions calculated from Elwert corrected (non relativistic) Bethe-Heitler [EBH] theory, modified Elwert factor (relativistic) Bethe-Heitler (FmodBH) theory for ordinary bremsstrahlung (OB) and the modified Elwert factor (relativistic) Bethe-Heitler (FmodBH+PB) theory, which includes the polarization bremsstrahlung (PB) into total bremsstrahlung (BS). The present results indicate the correctness of FmodBH+PB theory in the low energy region, where the contributions of PB into BS are dominant, which is described in terms of stripped atom (SA) approximation. But at the middle and higher energy region of the bremsstrahlung spectrum, where the contribution of PB is negligible, the FmodBH theory is more close to the experimental results. Hence, it is clear that the production of PB in the low energy region, due to the dynamic response of the target atom suppresses the production of bremsstrahlung at higher energy ends

  6. Bremsstrahlung in Mo and Pt targets produced by {sup 90}Sr beta particles in the photon energy region of 1-100 keV

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Amrit; Dhaliwal, A. S., E-mail: dhaliwalas@hotmail.com [Department of Physics, Sant Longowal Institute of Engineering and Technology, Longowal(Sangrur) -148106, Punjab (India)

    2015-08-28

    Bremsstrahlung spectra in thick targets of Mo and Pt, produced by beta emitter {sup 90}Sr (end point energy = 546 keV) have been studied in the photon energy range of 1-100 keV. The experimentally measured bremsstrahlung spectra measured with Si(Li) detector were compared with the theoretical spectral distributions calculated from Elwert corrected (non relativistic) Bethe-Heitler [EBH] theory, modified Elwert factor (relativistic) Bethe-Heitler (F{sub mod}BH) theory for ordinary bremsstrahlung (OB) and the modified Elwert factor (relativistic) Bethe-Heitler (F{sub mod}BH+PB) theory, which includes the polarization bremsstrahlung (PB) into total bremsstrahlung (BS). The present results indicate the correctness of F{sub mod}BH+PB theory in the low energy region, where the contributions of PB into BS are dominant, which is described in terms of stripped atom (SA) approximation. But at the middle and higher energy region of the bremsstrahlung spectrum, where the contribution of PB is negligible, the F{sub mod}BH theory is more close to the experimental results. Hence, it is clear that the production of PB in the low energy region, due to the dynamic response of the target atom suppresses the production of bremsstrahlung at higher energy ends.

  7. Bremsstrahlung in Mo and Pt targets produced by 90Sr beta particles in the photon energy region of 1-100 keV

    Science.gov (United States)

    Singh, Amrit; Dhaliwal, A. S.

    2015-08-01

    Bremsstrahlung spectra in thick targets of Mo and Pt, produced by beta emitter 90Sr (end point energy = 546 keV) have been studied in the photon energy range of 1-100 keV. The experimentally measured bremsstrahlung spectra measured with Si(Li) detector were compared with the theoretical spectral distributions calculated from Elwert corrected (non relativistic) Bethe-Heitler [EBH] theory, modified Elwert factor (relativistic) Bethe-Heitler (FmodBH) theory for ordinary bremsstrahlung (OB) and the modified Elwert factor (relativistic) Bethe-Heitler (FmodBH+PB) theory, which includes the polarization bremsstrahlung (PB) into total bremsstrahlung (BS). The present results indicate the correctness of FmodBH+PB theory in the low energy region, where the contributions of PB into BS are dominant, which is described in terms of stripped atom (SA) approximation. But at the middle and higher energy region of the bremsstrahlung spectrum, where the contribution of PB is negligible, the FmodBH theory is more close to the experimental results. Hence, it is clear that the production of PB in the low energy region, due to the dynamic response of the target atom suppresses the production of bremsstrahlung at higher energy ends.

  8. Implications on obtained data, electronics and DAQ-system by the use of dense detector setups in beta-decay studies

    International Nuclear Information System (INIS)

    Beta-decay investigations of light nuclei close to the drip lines have revealed new and intriguing features of nuclear structure. However, to fully investigate the decay pattern of these nuclei, new detector systems with an increased granularity have to be implemented. The use of segmented detectors as, for example, the Double-Sided Silicon Strip Detectors has thus proven to give fantastic improvements on the quality of the obtained data. The extra granularity allows for discrimination between sequentially or directly emitted charged particles and thus to follow decay patterns of delayed particle emission

  9. Targeted Cancer Therapy with a Novel Anti-CD37 Beta-Particle Emitting Radioimmunoconjugate for Treatment of Non-Hodgkin Lymphoma.

    Directory of Open Access Journals (Sweden)

    Ada H V Repetto-Llamazares

    Full Text Available 177Lu-DOTA-HH1 (177Lu-HH1 is a novel anti-CD37 radioimmunoconjugate developed to treat non-Hodgkin lymphoma. Mice with subcutaneous Ramos xenografts were treated with different activities of 177Lu-HH1, 177Lu-DOTA-rituximab (177Lu-rituximab and non-specific 177Lu-DOTA-IgG1 (177Lu-IgG1 and therapeutic effect and toxicity of the treatment were monitored. Significant tumor growth delay and increased survival of mice were observed in mice treated with 530 MBq/kg 177Lu-HH1 as compared with mice treated with similar activities of 177Lu-rituximab or non-specific 177Lu-IgG1, 0.9% NaCl or unlabeled HH1. All mice injected with 530 MBq/kg of 177Lu-HH1 tolerated the treatment well. In contrast, 6 out of 10 mice treated with 530 MBq/kg 177Lu-rituximab experienced severe radiation toxicity. The retention of 177Lu-rituximab in organs of the mononuclear phagocyte system was longer than for 177Lu-HH1, which explains the higher toxicity observed in mice treated with 177Lu-rituximab. In vitro internalization studies showed that 177Lu-HH1 internalizes faster and to a higher extent than 177Lu-rituximab which might be the reason for the better therapeutic effect of 177Lu-HH1.

  10. Calculation of particle and quark masses solely using the fine structure constant alpha, the nucleon/electron mass ratio beta and the electron mass

    International Nuclear Information System (INIS)

    A surprisingly simple relationship for particle and quark masses is given as m = x*y*me. Thereby y = 1 and x = 1/α, β and β/α for a hypothetic mass m0, the nucleon and the Higgs boson. With y = 4/3 instead y = 1 one obtains the masses of the strange-, charm-, and top quark, with x = β/α and y = 2/π the Z boson and with the π-2 fold thereof the W boson. The aforementioned m0 is the building block for calculating, as integer multiples, all other meson- and baryon masses with better than 2 % accuracy.

  11. Chemical Imaging of Catalyst Deactivation during the Conversion of Renewables at the Single Particle Level: The Etherification of Biomass-based Polyols with Alkenes over H-Beta Zeolites

    Energy Technology Data Exchange (ETDEWEB)

    A Parvulescu; D Mores; E Stavitski; C Teodorescu; P Bruijnicx; R Klein Gebbing; B Weckhuysen

    2011-12-31

    The etherification of biomass-based alcohols with various linear {alpha}-olefins under solvent-free conditions was followed in a space- and time-resolved manner on 9 {micro}m large H-Beta zeolite crystals by confocal fluorescence microscopy. This allowed us to visualize the interaction with the substrate and distribution of the coke products into the catalyst at the level of an individual zeolite crystal during the etherification process. The spectroscopic information obtained on the micrometer-scale zeolite was in line with the results obtained with bulk characterization techniques and further confirmed by the catalytic results obtained both for micrometer-scale and nanoscale zeolites. This allowed us to explain the influence of the substrate type (glycerol, glycols, and alkenes) and zeolite properties (Si/Al ratio and particle size) on the etherification activity. The etherification of the biomass-based alcohols takes place mainly on the external surface of the zeolite particles. The gradual blockage of the external surface of the zeolite results in a partial or total loss of etherification activity. The deactivation could be attributed to olefin oligomerization. The high conversions obtained in the etherification of 1,2-propylene glycol with long linear alkenes (up to 80%) and the pronounced deactivation of the zeolite observed in the etherification of glycerol with long linear alkenes (max. 20% conversion) were explained by the spectroscopic measurements and is due to differences in the adsorption, i.e., in the center of the zeolite particle for glycerol and on the external surface in the case of glycols.

  12. A Delayed Choice Quantum Eraser

    OpenAIRE

    Kim, Yoon-Ho; R. Yu; Kulik, S. P.; Shih, Y. H.; Scully, Marlan O.

    1999-01-01

    This paper reports a "delayed choice quantum eraser" experiment proposed by Scully and Dr\\"{u}hl in 1982. The experimental results demonstrated the possibility of simultaneously observing both particle-like and wave-like behavior of a quantum via quantum entanglement. The which-path or both-path information of a quantum can be erased or marked by its entangled twin even after the registration of the quantum.

  13. Ingesting a pre-workout supplement containing caffeine, B-vitamins, amino acids, creatine, and beta-alanine before exercise delays fatigue while improving reaction time and muscular endurance

    Directory of Open Access Journals (Sweden)

    Spradley Brandon D

    2012-03-01

    Full Text Available Abstract Background The purpose of this study was to determine the effects of the pre-workout supplement Assault™ (MusclePharm, Denver, CO, USA on upper and lower body muscular endurance, aerobic and anaerobic capacity, and choice reaction time in recreationally-trained males. Subjective feelings of energy, fatigue, alertness, and focus were measured to examine associations between psychological factors and human performance. Methods Twelve recreationally-trained males participated in a 3-week investigation (mean +/- SD, age: 28 +/- 5 y, height: 178 +/- 9 cm, weight: 79.2 +/- 15.7 kg, VO2max: 45.7 +/- 7.6 ml/kg/min. Subjects reported to the human performance laboratory on three separate occasions. All participants completed a baseline/familiarization day of testing that included a maximal graded exercise test for the determination of aerobic capacity (VO2max, one-rep maximum (1-RM for bench and leg press to determine 75% of 1-RM, choice reaction tests, and intermittent critical velocity familiarization. Choice reaction tests included the following: single-step audio and visual, one-tower stationary protocol, two-tower lateral protocol, three-tower multi-directional protocol, and three-tower multi-directional protocol with martial arts sticks. Subjects were randomly assigned to ingest either the supplement (SUP or the placebo (PL during Visit 2. Subjects were provided with the cross-over treatment on the last testing visit. Testing occurred 20 min following ingestion of both treatments. Results Significant (p Conclusions Ingesting the SUP before exercise significantly improved agility choice reaction performance and lower body muscular endurance, while increasing perceived energy and reducing subjective fatigue. These findings suggest that the SUP may delay fatigue during strenuous exercise.

  14. A quantum delayed-choice experiment.

    Science.gov (United States)

    Peruzzo, Alberto; Shadbolt, Peter; Brunner, Nicolas; Popescu, Sandu; O'Brien, Jeremy L

    2012-11-01

    Quantum systems exhibit particle- or wavelike behavior depending on the experimental apparatus they are confronted by. This wave-particle duality is at the heart of quantum mechanics. Its paradoxical nature is best captured in the delayed-choice thought experiment, in which a photon is forced to choose a behavior before the observer decides what to measure. Here, we report on a quantum delayed-choice experiment in which both particle and wave behaviors are investigated simultaneously. The genuinely quantum nature of the photon's behavior is certified via nonlocality, which here replaces the delayed choice of the observer in the original experiment. We observed strong nonlocal correlations, which show that the photon must simultaneously behave both as a particle and as a wave. PMID:23118183

  15. BETA. A code for {beta}{sub eff} measurement and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Yuichi; Okajima, Shigeaki; Sakurai, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-03-01

    The code BETA has been developed to calculate the following reactor physics parameters which are used for the {beta}{sub eff} measurement and analysis; Diven factor, Spatial correction factor (g-factor) for neutron correlation experiment, Adjoint weighted g-factor, Fission rate integrated in whole reactor and Adjoint weighted fission rate integrated in whole reactor: The code also calculates the effective delayed neutron fraction with different evaluated delayed neutron data. These parameters are calculated with using the forward and adjoint fluxes given by SLAROM, POPLARS or TWOTRAN-II. This report describes the input data and job control statements instructions, file requirements and sample input output data. (author)

  16. Multiwire proportional counter (lecture by an electromagnetic delay line)

    International Nuclear Information System (INIS)

    For track localisation of ionizing particles with multiwire proportional chamber, an electronic chain including amplifying, shaping and memorizing circuits is required for each wire. In order to lower the cost of this type of detector, an electromagnetic delay line is proposed among various possibilities. In this paper, different coupling modes between chamber and delay line are studied with their respective advantages. The realization of one meter long delay line with a unit delay time of 15 ns per cm is also presented

  17. Double beta decay: A theoretical overview

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, S.P.

    1988-01-01

    This paper reviews the theoretical possibility of double beta decay. The titles of the main sections of this paper are: Nuclear physics setting; Particle physics requirements; Kinematical features of the decay modes; Nuclear matrix elements; the Shell model and two-neutrino decay; Quasi-particle random phase approximation; and Future considerations. 18 refs., 7 tabs. (LSP)

  18. BETA-S, Multi-Group Beta-Ray Spectra

    International Nuclear Information System (INIS)

    1 - Description of program or function: BETA-S calculates beta-decay source terms and energy spectra in multigroup format for time-dependent radionuclide inventories of actinides, fission products, and activation products. Multigroup spectra may be calculated in any arbitrary energy-group structure. The code also calculates the total beta energy release rate from the sum of the average beta-ray energies as determined from the spectral distributions. BETA-S also provides users with an option to determine principal beta-decaying radionuclides contributing to each energy group. The CCC-545/SCALE 4.3 (or SCALE4.2) code system must be installed on the computer before installing BETA-S, which requires the SCALE subroutine library and nuclide-inventory generation from the ORIGEN-S code. 2 - Methods:Well-established models for beta-energy distributions are used to explicitly represent allowed, and 1., 2. - and 3. -forbidden transition types. Forbidden non-unique transitions are assumed to have a spectral shape of allowed transitions. The multigroup energy spectra are calculated by numerically integrating the energy distribution functions using an adaptive Simpson's Rule algorithm. Nuclide inventories are obtained from a binary interface produced by the ORIGEN-S code. BETA-S calculates the spectra for all isotopes on the binary interface that have associated beta-decay transition data in the ENSDF-95 library, developed for the BETA-S code. This library was generated from ENSDF data and contains 715 materials, representing approximately 8500 individual beta transition branches. 3 - Restrictions on the complexity of the problem: The algorithms do not treat positron decay transitions or internal conversion electrons. The neglect of positron transitions in inconsequential for most applications involving aggregate fission products, since most of the decay modes are via electrons. The neglect of internal conversion electrons may impact on the accuracy of the spectrum in the low

  19. Teaching Elementary Particle Physics, Part II

    Science.gov (United States)

    Hobson, Art

    2011-01-01

    In order to explain certain features of radioactive beta decay, Wolfgang Pauli suggested in 1930 that the nucleus emitted, in addition to a beta particle, another particle of an entirely new type. The hypothesized particle, dubbed the neutrino, would not be discovered experimentally for another 25 years. It's not easy to detect neutrinos, because…

  20. Review of double beta experiments

    OpenAIRE

    Sarazin, X.

    2012-01-01

    C13-10-22.1 International audience This paper gives a review of the double beta experimental techniques and projects, in the search for the Majorana neutrino. The purpose of this review is to detail, for each technique, the different origins of background, how they can be identified, and how they can be reduced. Advantages and limitations of the different techniques are discussed. 1. Introduction The neutrino is one of the most puzzling elementary particle with very unique properties. I...

  1. Neutrinoless Double Beta Decay Experiments

    OpenAIRE

    Zuber, K.

    2014-01-01

    Neutrinoless double beta decay is the only process known so far able to test the neutrino intrinsic nature: its experimental observation would imply that the lepton number is violated by two units and prove that neutrinos have a Majorana mass components, being their own anti-particle. While several experiments searching for such a rare decay have been performed in the past, a new generation of experiments using different isotopes and techniques have recently released their results or are taki...

  2. The search for neutrinoless double beta decay

    CERN Document Server

    Gomez-Cadenas, J J; Mezzetto, M; Monrabal, F; Sorel, M

    2011-01-01

    In the last few years the search for neutrinoless double beta decay has evolved from being almost a marginal activity in neutrino physics to one of the highest priorities for understanding neutrinos and the origin of mass. There are two main reasons for this paradigm shift: the discovery of neutrino oscillations, which clearly established the existence of massive neutrinos; and the existence of an unconfirmed, but not refuted, claim of evidence for neutrinoless double decay in 76Ge. As a consequence, a new generation of experiments, employing different detection techniques and {\\beta}{\\beta} isotopes, is being actively promoted by experimental groups across the world. In addition, nuclear theorists are making remarkable progress in the calculation of the neutrinoless double beta decay nuclear matrix elements, thus eliminating a substantial part of the theoretical uncertainties affecting the particle physics interpretation of this process. In this report, we review the main aspects of the double beta decay pro...

  3. Simultaneous beta/gamma digital spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.

    A state-of-the-art radiation detection system for simultaneous spectroscopy of beta-particles and gamma-rays has been developed. The system utilizes a triple-layer phoswich detector and a customized Digital Pulse Processor (DPP) built in our laboratory. The DPP board was designed to digitally capture the analog signal pulses and, following several digital preprocessing steps, transfer valid pulses to the host computer for further digital processing. A MATLAB algorithm was developed to digitally discriminate beta and gamma events and reconstruct separate beta and gamma-ray energy spectra with minimum crosstalk. The spectrometer proved to be an effective tool for recording separate beta and gamma-ray spectra from mixed radiation fields. The system as a beta-gamma spectrometer will have broad-ranging applications in nuclear non-proliferation, radioactive waste management, worker safety, systems reliability, dose assessment, and risk analysis.

  4. An Analytical Delay Model

    Institute of Scientific and Technical Information of China (English)

    MIN Yinghua; LI Zhongcheng

    1999-01-01

    Delay consideration has been a majorissue in design and test of high performance digital circuits. Theassumption of input signal change occurring only when all internal nodesare stable restricts the increase of clock frequency. It is no longertrue for wave pipelining circuits. However, previous logical delaymodels are based on the assumption. In addition, the stable time of arobust delay test generally depends on the longest sensitizable pathdelay. Thus, a new delay model is desirable. This paper explores thenecessity first. Then, Boolean process to analytically describe thelogical and timing behavior of a digital circuit is reviewed. Theconcept of sensitization is redefined precisely in this paper. Based onthe new concept of sensitization, an analytical delay model isintroduced. As a result, many untestable delay faults under thelogical delay model can be tested if the output waveforms can be sampledat more time points. The longest sensitizable path length is computedfor circuit design and delay test.

  5. Searches for neutrinoless double beta decay

    Science.gov (United States)

    Schwingenheuer, Bernhard

    2012-07-01

    Neutrinoless double beta decay is a lepton number violating process whose observation would also establish that neutrinos are their own anti-particles. There are many experimental efforts with a variety of techniques. Some (EXO, Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has reported the first measurement of the half life for the double beta decay with two neutrinos of 136Xe. The sensitivities of the different proposals are reviewed.

  6. Searches for neutrinoless double beta decay

    CERN Document Server

    Schwingenheuer, B

    2012-01-01

    Neutrinoless double beta decay is a lepton number violating process whose observation would also establish that neutrinos are their own anti-particles. There are many experimental efforts with a variety of techniques. Some (EXO, Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has reported the first measurement of the half life for the double beta decay with two neutrinos of $^{136}$Xe. The sensitivities of the different proposals are reviewed.

  7. Composite delayed-neutron spectra from U-235

    International Nuclear Information System (INIS)

    Delayed-neutron spectra from thermal neutron-induced fission of U-235 have been measured over the neutron energy range, .01 - 2.0 MeV, for delay times following fission ranging from 0.17 - 85.5 s. A helium jet system was used for the rapid transport of fission products to a low-background area, where the spectra were determined from beta-neutron correlations using the neutron time-of-flight method

  8. The shark bile salt 5 beta-scymnol abates acetaminophen toxicity, but not covalent binding.

    Science.gov (United States)

    Slitt, Angela Lucas; Naylor, Lee; Hoivik, J; Manautou, Jose E; Macrides, Theo; Cohen, Steven D

    2004-10-15

    Acetaminophen (APAP) toxicity involves both arylative and oxidative mechanisms. The shark bile salt, 5 beta-scymnol (5beta-S), has been demonstrated to act as an antioxidant and free radical scavenger in vitro. To determine if 5beta-S protects against either APAP-induced hepatic or renal toxicity, 3-4-month-old male Swiss Laca mice were given APAP (500 mg/kg), and 5beta-S (100 mg/kg) was given at 0 and 2 h after APAP. Plasma SDH at 12 h after APAP alone was 1630 U/l and BUN was 19 mg/dl versus 20 U/l and 10 mg/dl, respectively, in controls. Either simultaneous or 2 h delayed treatment with 5beta-S significantly decreased the APAP-induced SDH increase while only the simultaneous pretreatment prevented the BUN elevation. 5beta-S alone did not increase liver glutathione content. Western analysis of APAP covalent binding using anti-APAP antibodies indicated the 5beta-S did not alter protein arylation either qualitatively or quantitatively. These results suggest that 5beta-S treatment did not impair APAP activation and are consistent with 5beta-S protection that likely results from its antioxidant activity. PMID:15363587

  9. Beta and gamma decay heat measurements between 0.1s--50,000s for neutron fission of 235U, 238U and 239Pu

    International Nuclear Information System (INIS)

    A helium-jet/tape-transport system is employed in the study of beta-particle and gamma-ray energy spectra of aggregate fission products as a function of time after fission. During the initial nine months of this project we have investigated the following areas: Design, assembly and characterization of a beta-particle spectrometer; Measurement of 235U(nthff) beta spectra for delay times 0.2 s to 12,000 s; Assembly and characterization of a 5 x 5 Nal(Tl) gamma-ray spectrometer; Measurement of 235U(nthff) gamma-ray spectra for delay times 0.2s to 1 5,500s; Assembly and characterization of HPGe gamma-ray spectrometer with a Nal(Tl) Compton-and-background-suppression annulus; Measurement of 235U(n th,ff) high-resolution gamma-ray spectra for delay times 0.6 s to over 100,000 s; Comparison of individual gamma-line intensities with ENDF/B-VI; Adaptation to our computer of unfolding program FERDO for beta and gamma aggregate fission-product energy spectra and development of a spectrum-stripping program for analysis of HPGe gamma-ray spectra; Study of the helium-jet fission-fragment elemental transfer efficiency. This work has resulted in the publication of twelve BAPS abstracts of presentations at scientific meetings. There are currently four Ph.D. and two M.S. candidates working on dissertations associated with the project

  10. Beta decay of the exotic $T_z$ = -2 nuclei $^{48}$Fe, $^{52}$Ni and $^{56}$Zn

    OpenAIRE

    Orrigo, S. E. A.; Rubio, B.; Fujita, Y; Gelletly, W.; Agramunt, J.; Algora, A.; Ascher, P; Bilgier, B.; Blank, B.; Cáceres, L.; Cakirli, R. B.; Ganioğlu, E.; Gerbaux, M.; Giovinazzo, J.; Grévy, S.

    2016-01-01

    The results of a study of the beta decays of three proton-rich nuclei with $T_z=\\text{-}2$, namely $^{48}$Fe, $^{52}$Ni and $^{56}$Zn, produced in an experiment carried out at GANIL, are reported. In all three cases we have extracted the half-lives and the total $\\beta$-delayed proton emission branching ratios. We have measured the individual $\\beta$-delayed protons and $\\beta$-delayed $\\gamma$ rays and the branching ratios of the corresponding levels. Decay schemes have been determined for t...

  11. Delayed Gambler's Ruin

    CERN Document Server

    Imai, Tomohisa

    2016-01-01

    We present here a new extended model of the gambler's ruin problem by incorporating delays in receiving of rewards and paying of penalties. When there is a difference between two delays, an exact analysis of the ruin probability is difficult. We derive an approximate scheme to find an effective shift in the initial assets of the gambler. Through comparison against computer simulations, this approximation is shown to work for small differences between the two delays.

  12. Consistent Histories and Quantum Delayed Choice

    OpenAIRE

    Griffiths, Robert B.

    1998-01-01

    John Wheeler devised a gedanken experiment in which a piece of apparatus can be altered just before the arrival of particle, and this ``delayed choice'' can, seemingly, alter the quantum state of the particle at a much earlier time, long before the choice is made. A slightly different gedanken experiment, which exhibits the same conceptual difficulty, is analyzed using the techniques of consistent history quantum theory. The idea that the future influences the past disappears when proper acco...

  13. VARIABLE TIME DELAY MEANS

    Science.gov (United States)

    Clemensen, R.E.

    1959-11-01

    An electrically variable time delay line is described which may be readily controlled simuitaneously with variable impedance matching means coupied thereto such that reflections are prevented. Broadly, the delay line includes a signal winding about a magnetic core whose permeability is electrically variable. Inasmuch as the inductance of the line varies directly with the permeability, the time delay and characteristic impedance of the line both vary as the square root of the permeability. Consequently, impedance matching means may be varied similariy and simultaneously w:th the electrically variable permeability to match the line impedance over the entire range of time delay whereby reflections are prevented.

  14. A Characteristic Particle Length

    CERN Document Server

    Roberts, Mark D

    2015-01-01

    It is argued that there are characteristic intervals associated with any particle that can be derived without reference to the speed of light $c$. Such intervals are inferred from zeros of wavefunctions which are solutions to the Schr\\"odinger equation. The characteristic length is $\\ell=\\beta^2\\hbar^2/(8Gm^3)$, where $\\beta=3.8\\dots$; this length might lead to observational effects on objects the size of a virus.

  15. Three-dimensional drift chambers of the DCBA experiment for neutrinoless double beta decay search

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, T., E-mail: ishikawat@hakone.phys.metro-u.ac.j [Tokyo Metropolitan University, Hachioji, Tokyo 192-0398 (Japan); Igarashi, H.; Sumiyoshi, T. [Tokyo Metropolitan University, Hachioji, Tokyo 192-0398 (Japan); Ishihara, N.; Iwai, G.; Iwase, H.; Kato, Y.; Kawai, M.; Kondou, Y.; Haruyama, T.; Inagaki, T.; Makida, Y.; Ohama, T.; Takahashi, K.; Yamada, Y. [High Energy Accel, Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Tashiro, E.; Ishizuka, T. [Shizuoka University, Naka, Hamamatsu, Shizuoka 432-8011 (Japan); Kitamura, S. [Nihon Institute of Medical Science, Iruma-gun, Saitama 350-0435 (Japan); Teramoto, Y. [Osaka City University, Sumiyoshi, Osaka 558-8585 (Japan); Nakano, I. [Okayama University, Okayama 700-8530 (Japan)

    2011-02-01

    The aim of the DCBA (Drift Chamber Beta-ray Analyzer) experiment is to search for neutrinoless double beta decay (0{nu}{beta}{beta}). The half-life of 0{nu}{beta}{beta} is expected to give us the information of Majorana nature and the absolute mass scale of neutrinos. A prototype test apparatus DCBA-T2 has the energy resolution of about 150 keV (FWHM) around 1 MeV. In order to check the detector performance, engineering runs detecting double beta decay of {sup 100}Mo started in May 2009 using natural Mo, which contains 9.6% of {sup 100}Mo. Ten candidates of the double beta decay ({beta}{beta}) have been detected so far. It has been found that the background events due to {sup 214}Bi decay are distinguishable from the double beta decays by detecting {alpha}-particles from {sup 214}Po.

  16. On Tuning PI Controllers for Integrating Plus Time Delay Systems

    Directory of Open Access Journals (Sweden)

    David Di Ruscio

    2010-10-01

    Full Text Available Some analytical results concerning PI controller tuning based on integrator plus time delay models are worked out and presented. A method for obtaining PI controller parameters, Kp=alpha/(k*tau, and, Ti=beta*tau, which ensures a given prescribed maximum time delay error, dtau_max, to time delay, tau, ratio parameter delta=dau_max/tau, is presented. The corner stone in this method, is a method product parameter, c=alpha*beta. Analytical relations between the PI controller parameters, Ti, and, Kp, and the time delay error parameter, delta, is presented, and we propose the setting, beta=c/a*(delta+1, and, alpha=a/(delta+1, which gives, Ti=c/a*(delta+1*tau, and Kp=a/((delta+1*k*tau, where the parameter, a, is constant in the method product parameter, c=alpha*beta. It also turns out that the integral time, Ti, is linear in, delta, and the proportional gain, Kp, inversely proportional to, delta+1. For the original Ziegler Nichols (ZN method this parameter is approximately, c=2.38, and the presented method may e.g., be used to obtain new modified ZN parameters with increased robustness margins, also documented in the paper.

  17. Levered and unlevered Beta

    OpenAIRE

    Fernandez, Pablo

    2003-01-01

    We prove that in a world without leverage cost the relationship between the levered beta ( L) and the unlevered beta ( u) is the No-costs-of-leverage formula: L = u + ( u - d) D (1 - T) / E. We also analyze 6 alternative valuation theories proposed in the literature to estimate the relationship between the levered beta and the unlevered beta (Harris and Pringle (1985), Modigliani and Miller (1963), Damodaran (1994), Myers (1974), Miles and Ezzell (1980), and practitioners) and prove that all ...

  18. Testing the Delayed Gamma Capability in MCNP6

    Energy Technology Data Exchange (ETDEWEB)

    Weldon, Robert A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fensin, Michael L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); McKinney, Gregg W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-28

    The mission of the Domestic Nuclear Detection Office is to quickly and reliably detect unauthorized attempts to import or transport special nuclear material for use against the United States. Developing detection equipment to meet this objective requires accurate simulation of both the detectable signature and detection mechanism. A delayed particle capability was initially added to MCNPX 2.6.A in 2005 to sample the radioactive fission product parents and emit decay particles resulting from the decay chain. To meet the objectives of detection scenario modeling, the capability was designed to sample a particular time for emitting particular multiplicity of a particular energy. Because the sampling process of selecting both time and energy is interdependent, to linearize the time and emission sampling, atom densities are computed at several discrete time steps, and the time-integrated production is computed by multiplying the atom density by the decay constant and time step size to produce a cumulative distribution function for sampling the emission time, energy, and multiplicity. The delayed particle capability was initially given a time-bin structure to help reasonably reproduce, from a qualitative sense, a fission benchmark by Beddingfield, which examined the delayed gamma emission. This original benchmark was only qualitative and did not contain the magnitudes of the actual measured data but did contain relative graphical representation of the spectra. A better benchmark with measured data was later provided by Hunt, Mozin, Reedy, Selpel, and Tobin at the Idaho Accelerator Center; however, because of the complexity of the benchmark setup, sizable systematic errors were expected in the modeling, and initial results compared to MCNPX 2.7.0 showed errors outside of statistical fluctuation. Presented in this paper is a more simplified approach to benchmarking, utilizing closed form analytic solutions to the granddaughter equations for particular sets of decay systems

  19. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    .S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return of the...

  20. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward-...

  1. Dynamic Network Delay Cartography

    CERN Document Server

    Rajawat, Ketan; Giannakis, Georgios B

    2012-01-01

    Path delays in IP networks are important metrics, required by network operators for assessment, planning, and fault diagnosis. Monitoring delays of all source-destination pairs in a large network is however challenging and wasteful of resources. The present paper advocates a spatio-temporal Kalman filtering approach to construct network-wide delay maps using measurements on only a few paths. The proposed network cartography framework allows efficient tracking and prediction of delays by relying on both topological as well as historical data. Optimal paths for delay measurement are selected in an online fashion by leveraging the notion of submodularity. The resulting predictor is optimal in the class of linear predictors, and outperforms competing alternatives on real-world datasets.

  2. Deterministically delayed pseudofractal networks

    International Nuclear Information System (INIS)

    On the basis of pseudofractal networks (PFNs), we propose a family of delayed pseudofractal networks (DPFNs) with a special feature that newly added edges delay producing new nodes, differing from the evolution algorithms of PFNs where all existing edges simultaneously generate new nodes. We obtain analytical formulae for degree distribution, clustering coefficient (C) and average path length (APL). We compare DPFNs and PFNs, and show that the exponent of the degree distribution of DPFNs is smaller than that of PFNs, meaning that the heterogeneity of this kind of delayed network is higher. Compared to PFNs, small-world features of DPFNs are more prominent (larger C and smaller APL). We also find that the delay strengthens the scale-free and small-world characteristics of DPFNs. In addition, we calculate and compare the mean first passage time (MFPT) numerically, revealing that the MFPT of DPFNs is shorter. Our study may help with a deeper understanding of various deterministically growing delayed networks

  3. Studies of the $\\beta$-decay of Kr and Sr nuclei on and near the N=Z line with a Total Absorption $\\gamma$-ray Spectrometer

    CERN Multimedia

    2002-01-01

    It is proposed to measure the Gamow-Teller strength distribution in the decays of $^{71-75}$Kr and $^{75,76}$Sr using a Total Absorption Gamma-ray Spectrometer (TAGS) based on a large NaI(TI) detector. The $\\gamma$-rays emitted in these decays will be detected in the TAGS in coincidence with positrons and X-rays from electron capture. Measurements of $\\beta$-delayed particles will also be performed in coincidence with the TAGS. Comparison with theoretical calculations based on the mean field approach, Tamm-Dancoff and QRPA method should allow a determination of the shapes of the ground states of these nuclei.

  4. The spectrum of particles accelerated in relativistic, collisionless shocks

    OpenAIRE

    Keshet, Uri; Waxman, Eli

    2004-01-01

    We analytically study diffusive particle acceleration in relativistic, collisionless shocks. We find a simple relation between the spectral index s and the anisotropy of the momentum distribution along the shock front. Based on this relation, we obtain s = (3beta_u - 2beta_u*beta_d^2 + beta_d^3) / (beta_u - beta_d) for isotropic diffusion, where beta_u (beta_d) is the upstream (downstream) fluid velocity normalized to the speed of light. This result is in agreement with previous numerical det...

  5. Beta Beams for Precision Measurements of Neutrino Oscillation Parameters

    CERN Document Server

    Wildner, E; Hansen, C; De Melo Mendonca, T; Stora, T; Damjanovic, S; Payet, J; Chancé, A; Zorin, V; Izotov, I; Rasin, S; Sidorov, A; Skalyga, V; De Angelis, G; Prete, G; Cinausero, M; Kravchuk, V; Gramegna, F; Marchi, T; Collazuol, G; Mezzetto, M; Delbar, T; Loiselet, M; Keutgen, T; Mitrofanov, S; Burt, G; Dexter, A; Lamy, T; Latrasse, L; Marie-Jeanne, M; Sortais, P; Thuillier, T; Debray, F; Trophime, C; Hass, M; Hirsh, T; Berkovits, D; Stahl, A; Vardaci, E; Di Nitto, A; Brondi, A; La Rana, G; Moro, R; De Rosa, G; Palladino, V

    2012-01-01

    Neutrino oscillations have implications for the Standard Model of particle physics. The CERN Beta Beam has outstanding capabilities to contribute to precision measurements of the parameters governing neutrino oscillations. The FP7 collaboration EUROnu (2008-2012) is a design study that will review three facilities (Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance, will give means to the European research authorities to make decisions on future European neutrino oscillation facilities. ”Beta Beams” produce collimated pure electron (anti)neutrinos by accelerating beta active ions to high energies and having them decay in a storage ring. Using existing machines and infrastructure is an advantage for the cost evaluation; however, this choice is also constraining the Beta Beams. Recent work to make the Beta Beam facility a solid option will be described: production of Beta Beam isotopes, the 60 GHz pulsed ECR source development, integratio...

  6. Sizeable beta-strength in 31Ar (beta 3p) decay

    DEFF Research Database (Denmark)

    T. Koldste, G.; Blank, B.; J. G. Borge, M.;

    2014-01-01

    We present for the first time precise spectroscopic information on the recently discovered decay mode beta-delayed 3p-emission. The detection of the 3p events gives an increased sensitivity to the high energy part of the Gamow-Teller strength distribution from the decay of 31Ar revealing that as...... much as 30% of the strength resides in the beta-3p decay mode. A simplified description of how the main decay modes evolve as the excitation energy increases in 31Cl is provided....

  7. Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge

    CERN Document Server

    Brown, B A; Horoi, M

    2015-01-01

    The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...

  8. Power output and efficiency of beta-emitting microspheres

    International Nuclear Information System (INIS)

    Current standard methods to calculate the dose of radiation emitted during medical applications by beta-minus emitting microspheres rely on an over-simplistic formalism. This formalism is a function of the average activity of the radioisotope used and the physiological dimensions of the patient only. It neglects the variation in energy of the emitted beta particle due to self-attenuation, or self-absorption, effects related to the finite size of the sphere. Here it is assumed the sphere is comprised of a pure radioisotope with beta particles being emitted isotropically throughout the material. The full initial possible kinetic energy distribution of a beta particle is taken into account as well as the energy losses due to scattering by other atoms in the microsphere and bremsstrahlung radiation. By combining Longmire’s theory of the mean forward range of charged particles and the Rayleigh distribution to take into account the statistical nature of scattering and energy straggling, the linear attenuation, or self-absorption, coefficient for beta-emitting radioisotopes has been deduced. By analogy with gamma radiation transport in spheres, this result was used to calculate the rate of energy emitted by a beta-emitting microsphere and its efficiency. Comparisons to standard point dose kernel formulations generated using Monte Carlo data show the efficacy of the proposed method. Yttrium-90 is used as a specific example throughout, as a medically significant radioisotope, frequently used in radiation therapy for treating cancer. - Highlights: • Range-energy relationship for the beta particles in yttrium-90 is calculated. • Formalism for the semi-analytical calculation of self-absorption coefficients. • Energy-dependent self-absorption coefficient calculated for yttrium-90. • Flux rate of beta particles from a self-attenuating radioactive sphere is shown. • The efficiency of beta particle emitting radioactive microspheres is calculated

  9. Delay in Contests

    OpenAIRE

    Bester, Helmut; Konrad, Kai A.

    2003-01-01

    "Why is there delay in contests? In this paper we follow and extend the line of reasoning of Carl von Clausewitz to explain delay. For a given contest technology, delay may occur if there is an asymmetry between defense and attack, if the expected change in relative strengths is moderate, and if the additional cost of investment in future strength is low." (author's abstract) "In Konfliktsituationen findet der 'showdown' häufig mit einer Verzögerung statt. Das ist überraschend, weil sich m...

  10. Sensitive behavior of 2{nu}{beta}{beta}-decay amplitude within QRPA and broken SU(4) symmetry in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Rodin, Vadim A. [Institut fuer Theoretische Physik der Universitaet Tuebingen, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)]. E-mail: vadim.rodin@uni-tuebingen.de; Urin, Michael H. [Department of Theoretical Nuclear Physics, Moscow State Engineering and Physics Institute, 115409 Moscow (Russian Federation); Kernfysisch Versneller Institute, NL-9747AA Groningen (Netherlands); Faessler, Amand [Institut fuer Theoretische Physik der Universitaet Tuebingen, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)

    2005-01-24

    Making use of an identity transformation independent of a nuclear model, we represent the 2{nu}{beta}{beta}-amplitude as a sum of two terms. One term accounts for most of the sensitivity of the original 2{nu}{beta}{beta}-amplitude to gpp' for realistic gpp'{approx}1 (with gpp' being the ratio of the triplet and singlet p-p interaction strengths) and is determined by a specific energy-weighted sum rule. The sum rule depends only on the particle-particle residual interaction (being linear function of gpp' in the QRPA) and passes through zero at the point gpp'=1 where the Wigner SU(4) symmetry is restored in the p-p sector of the Hamiltonian. The second term in the decomposition of the 2{nu}{beta}{beta}-amplitude is demonstrated within the QRPA to be a much smoother function for the realistic values of gpp' than the original 2{nu}{beta}{beta}-amplitude. This term is mainly determined by the intensity of the spin-orbit interaction of the nuclear mean field. Thus, the analysis of the present work reveals the reasons for the sensitivity of the 2{nu}{beta}{beta}-amplitude to different components of the nuclear Hamiltonian and thereby can help in constraining nuclear model uncertainties in calculations of the amplitude.

  11. Association behavior of native beta-lactoglobulin

    DEFF Research Database (Denmark)

    Verheul, M.; Pedersen, J.S.; Roefs, S.P.F.M.; Kruif, K.G. de

    1999-01-01

    samples were obtained. These functions provided information on the maximum size, the weight-averaged molecular mass, and the z-averaged radius of gyration oo the the beta-lactoglobulin particles. Al room temperature and pH values below 4 and above IZ the protein consists predominantly of monomers and...

  12. commensurate point delays

    Directory of Open Access Journals (Sweden)

    M. de la Sen

    2005-01-01

    nominal controller is maintained. In the current approach, the finite spectrum assignment is only considered as a particular case of the designer's choice of a (delay-dependent arbitrary spectrum assignment objective.

  13. Vernier Delay Unit

    International Nuclear Information System (INIS)

    This module will accept differential ECL pulses from the auxiliary rear panel or NIM level pulses from the front panel. The pulses are produced at the output with a fixed delay that is software programmable in steps of 0.1 ns over the range of 0.1 to 10.5 ns. Multiple outputs are available at the front panel. Minimum delay through the module is 9 ns

  14. Delayed Product Introduction

    OpenAIRE

    Kai-Lung Hui; Qiu-Hong Wang

    2005-01-01

    We investigate the incentives of a monopolistic seller to delay the introduction of a new and improved version of his product. By analyzing a three-period model, we show that the seller may prefer to delay introducing a new product, even though the enabling technologies for the product are already available. The underlying motivation is analogous to that found in the durable goods monopolist literature – the seller suffers from a time inconsistency problem that causes his old and new products...

  15. Quad precision delay generator

    International Nuclear Information System (INIS)

    A Quad Precision Delay Generator delays a digital edge by a programmed amount of time, varying from nanoseconds to microseconds. The output of this generator has an amplitude of the order of tens of volts and rise time of the order of nanoseconds. This was specifically designed and developed to meet the stringent requirements of the plasma focus experiments. Plasma focus is a laboratory device for producing and studying nuclear fusion reactions in hot deuterium plasma. 3 figs

  16. α/β粒子在不同类型探测器上的能量响应及其等效因子的一致性%Energy Response of Detectors to Alpha/beta Particles and Compatibility of the Equivalent Factors

    Institute of Scientific and Technical Information of China (English)

    林炳兴; 李光宪; 林立雄

    2011-01-01

    通过测量不同类型探测器或同一类型探测器不同台(路)对不同能量α/β放射性粒子的计数效率和等效因子,比较它们之间等效因子的一致性,探讨各类型探测装置在总放射性测量中的适应性。结果显示,常用的3种探测器即复合有机闪烁体、流气式正比计数器、金硅面垒半导体探测器对总α和总β粒子的计数效率-粒子能量关系总体上一致,总α计数效率与能量呈指数关系,总β计数效率与能量呈对数关系,低能β出现偏转。3种探测器能量响应比对的实验结果显示,复合有机闪烁体和流气式正比计数器两者的α和β等效因子具有良好的一致性,而金硅面垒半导体探测器对α测量的等效因子与前两种探测器相似,但是对β粒子的能量响应有显著差异,低能β等效因子明显偏低,因此金硅面垒半导体探测器不宜于总放射性测量和食品卫生检验。%By measuring detect efficiency and equivalent factors of alpha/beta radiation with different energies on three types of detectors, this paper compares compatibility of their equivalent factors and discusses applicability of detectors to measuring total alpha/beta radiation. The result shows the relationship between efficiency of alpha/beta radiation and their energies on 3 types of detectors, such as scintillation and proportional and semiconductor counters, are overall identical. Alpha count efficiency display exponential relation with alpha-particle energy. While beta counf efficiency display logarithm relation with beta-particle energy, but the curves appears deflection at low energy. Comparison test of energy response also shows that alpha and beta equivalent factors of scintillation and proportional counters have a good compatibility, and alpha equivalent factors of the semiconductor counters are in good agreement with those of the above two types of counters, but beta equivalent factors have obvious difference, or

  17. $\\beta$3p- spectroscopy and P-$\\gamma$ width determination in the decay of $^{31}$Ar

    CERN Multimedia

    We propose to perform a detailed study of the $\\beta$-decay of the dripline nucleus $^{31}$Ar. This will allow a detailed study of the $\\beta$-delayed 3p-decay as well as provide important information on the resonances of $^{30}$S and $^{29}$P, in particular the ratio between the P- and $\\gamma$- partial widths relevant for astrophysics.

  18. Search for long-lived neutral particles in the final state of delayed photons and missing energy in proton-proton collisions at $\\sqrt s$ = 8 TeV

    CERN Document Server

    CMS Collaboration

    2015-01-01

    A search for long-lived neutral particles decaying into a photon and an un-detectable particle, such as gravitino, is performed using 19.1 fb$^{-1}$ of proton-proton collision data at $\\sqrt s$ = 8 TeV. We present a method which exploits the identification of long-lived particles by using the time measurement from the CMS Electromagnetic calorimeter. The method is most sensitive to a range of lifetimes ($\\tau$) from 1.6 ns to 34 ns and is nearly free from standard model background. No significant excess is observed above background expectation and an exclusion region is set with $95\\%$ confidence level in the context of Gauge Mediated Supersymmetry Breaking models. Taking the product of neutralino's production cross section and decay branching ratio, the upper limits on the cross section of a neutral particle are set with $95\\%$ confidence level for a range of mass and lifetime.

  19. Nonionic emulsion-mediated synthesis of zeolite beta

    Indian Academy of Sciences (India)

    Yuguo Shen; Ying Zhang; Chao Jin; Ying Cao; Wei Gao; Lishan Cui

    2011-07-01

    Zeolite beta synthesis was first carried out in a newly developed emulsion system containing nonionic polyoxyethylated alkylphenol surfactant, which showed interesting non-conventional features. Compared to the conventional hydrothermal synthesis of zeolite beta, the reported nonionic emulsion system showed a faster nucleation rate. Furthermore, the emulsion system could stabilize the beta product and retarded its further transformation to ZSM-5 even under the high crystallization temperature at 453 K. Additionally, the beta particle size could be tuned by the adoption of different lengths of alkyl chain in the surfactant and cosurfactant. Control experiments showed each emulsion component played a crucial role in the zeolite beta growth. The approach proposed in this paper might be extended to apply for the syntheses of other types of zeolites with particle size under control.

  20. Koedam {beta} factors revisited

    Energy Technology Data Exchange (ETDEWEB)

    Lawler, J.E. [Physics Department, University of Wisconsin, Madison, WI (United States); Doughty, D.A. [Perkin-Elmer Optoelectronics, Santa Clara, CA (United States); Lister, G.G. [OSRAM SYLVANIA Inc., Beverly, MA (United States)

    2002-07-21

    A Koedam {beta} factor makes it possible to compute the total output power in line radiation from a positive column discharge using a single radiance measurement normal to an aperture in the wall. The results of analytic derivations of {beta} factors are presented for columns with uniform ({beta}=1.0) and parabolic ({beta}=0.75) excitation rates per unit volume and with negligible opacity. A Monte Carlo code for simulating radiation trapping with a spatially uniform density of absorbing atoms is then used to determine {beta} factors as a function of opacity. The code includes partial frequency redistribution and a Voigt line shape with radiative broadening, resonance collisional broadening, and Doppler broadening. The resulting {beta} factors are found to be nearly independent of opacity over a wide range of column radii for spectral line shapes dominated by Doppler broadening or by resonance collisional broadening. Additional Monte Carlo simulations are used to study {beta} factors as a function of a non-uniform density of absorbing atoms from radial cataphoresis with line shapes dominated by Doppler broadening, foreign gas broadening, and resonance collisional broadening. Radial cataphoresis is found to increase {beta} factors in all cases. Geometrical effects, refraction, and imperfect transmission at the glass wall are studied and found to decrease {beta} factors. (author)

  1. Beta-energy averaging and beta spectra

    International Nuclear Information System (INIS)

    A simple yet highly accurate method for approximately calculating spectrum-averaged beta energies and beta spectra for radioactive nuclei is presented. This method should prove useful for users who wish to obtain accurate answers without complicated calculations of Fermi functions, complex gamma functions, and time-consuming numerical integrations as required by the more exact theoretical expressions. Therefore, this method should be a good time-saving alternative for investigators who need to make calculations involving large numbers of nuclei (e.g., fission products) as well as for occasional users interested in restricted number of nuclides. The average beta-energy values calculated by this method differ from those calculated by ''exact'' methods by no more than 1 percent for nuclides with atomic numbers in the 20 to 100 range and which emit betas of energies up to approximately 8 MeV. These include all fission products and the actinides. The beta-energy spectra calculated by the present method are also of the same quality

  2. Time-delayed autosynchronous swarm control

    Science.gov (United States)

    Biggs, James D.; Bennet, Derek J.; Dadzie, S. Kokou

    2012-01-01

    In this paper a general Morse potential model of self-propelling particles is considered in the presence of a time-delayed term and a spring potential. It is shown that the emergent swarm behavior is dependent on the delay term and weights of the time-delayed function, which can be set to induce a stationary swarm, a rotating swarm with uniform translation, and a rotating swarm with a stationary center of mass. An analysis of the mean field equations shows that without a spring potential the motion of the center of mass is determined explicitly by a multivalued function. For a nonzero spring potential the swarm converges to a vortex formation about a stationary center of mass, except at discrete bifurcation points where the center of mass will periodically trace an ellipse. The analytical results defining the behavior of the center of mass are shown to correspond with the numerical swarm simulations.

  3. Importance of neutrinoless double beta decay

    CERN Document Server

    Sarkar, Utpal

    2007-01-01

    A natural explanation for the smallness of the neutrino mass requires them to be Majorana particles violating lepton number by two units. Since lepton number violation can have several interesting consequences in particle physics and cosmology, it is of utmost importance to find out if there is lepton number violation in nature and what is its magnitude. The neutrinoless double beta decay experiment can answer these questions: if there is lepton number violation and if neutrinos are Majorana particles. In addition, the magnitude of neutrinoless double beta decay will constrain any other lepton number violating processes. This lepton number violation may also be relatd to the matter-antimatter asymmetry of the universe, dark matter and cosmological constant.

  4. Source preparations for alpha and beta measurements

    Energy Technology Data Exchange (ETDEWEB)

    Holm, E. [Risoe National Lab., Roskilde (Denmark)

    2001-01-01

    Regarding alpha particle emitters subject for environmental studies, electrodeposition or co-precipitation as fluorides are the most common methods. For electro deposition stainless steel is generally used as cathode material but also other metals such as Ni, Ag, and Cu showed promising results. The use of other anode material than platinum, such as graphite should be investigated. For other purposes such as optimal resolution other more sophisticated methods are used but often resulting in poorer recovery. For beta particle emitters the type of detection system will decide the source preparation. Similar methods as for alpha particle emitters, electrodeposition or precipitation techniques can be used. Due to the continuous energy distribution of the beta pulse height distribution a high resolution is not required. Thicker sources from the precipitates or a stable isotopic carrier can be accepted but correction for absorption in the source must be done. (au)

  5. Source preparations for alpha and beta measurements

    International Nuclear Information System (INIS)

    Regarding alpha particle emitters subject for environmental studies, electrodeposition or co-precipitation as fluorides are the most common methods. For electro deposition stainless steel is generally used as cathode material but also other metals such as Ni, Ag, and Cu showed promising results. The use of other anode material than platinum, such as graphite should be investigated. For other purposes such as optimal resolution other more sophisticated methods are used but often resulting in poorer recovery. For beta particle emitters the type of detection system will decide the source preparation. Similar methods as for alpha particle emitters, electrodeposition or precipitation techniques can be used. Due to the continuous energy distribution of the beta pulse height distribution a high resolution is not required. Thicker sources from the precipitates or a stable isotopic carrier can be accepted but correction for absorption in the source must be done. (au)

  6. Experimental demonstration of delayed-choice decoherence suppression.

    Science.gov (United States)

    Lee, Jong-Chan; Lim, Hyang-Tag; Hong, Kang-Hee; Jeong, Youn-Chang; Kim, M S; Kim, Yoon-Ho

    2014-01-01

    Wheeler's delayed-choice experiment illustrates vividly that the observer plays a central role in quantum physics by demonstrating that complementarity or wave-particle duality can be enforced even after the photon has already entered the interferometer. The delayed-choice quantum eraser experiment further demonstrates that complementarity can be enforced even after detection of a quantum system, elucidating the foundational nature of complementarity in quantum physics. However, the applicability of the delayed-choice method for practical quantum information protocols continues to be an open question. Here, we introduce and experimentally demonstrate the delayed-choice decoherence suppression protocol, in which the decision to suppress decoherence on an entangled two-qubit state is delayed until after the decoherence and even after the detection of a qubit. Our result suggests a new way to tackle Markovian decoherence in a delayed manner, applicable for practical entanglement distribution over a dissipative channel. PMID:25072967

  7. Helicity and nuclear $\\beta$ decay correlations

    CERN Document Server

    Hong, Ran; García, Alejandro

    2016-01-01

    We present simple derivations of nuclear $\\beta$-decay correlations with an emphasis on the special role of helicity. This provides a good opportunity to teach students about helicity and chirality in particle physics through exercises using simple aspects of quantum mechanics. In addition, this paper serves as an introduction to nuclear $\\beta$-decay correlations from both a theoretical and experimental vantage. This article can be used to introduce students to ongoing experiments searching for hints of new physics in the low-energy precision frontier.

  8. Card controlled beta backscatter thickness measuring instrument

    International Nuclear Information System (INIS)

    An improved beta backscatter instrument for the nondestructive measurement of the thickness of thin coatings on a substrate is described. Included therein is the utilization of a bank of memory stored data representative of isotope, substrate, coating material and thickness range characteristics in association with a control card having predetermined indicia thereon selectively representative of a particular isotope, substrate material, coating material and thickness range for conditioning electronic circuit means by memory stored data selected in accord with the predetermined indicia on a control card for converting backscattered beta particle counts into indicia of coating thickness

  9. Time Delay Cosmography

    CERN Document Server

    Treu, Tommaso

    2016-01-01

    Gravitational time delays, observed in strong lens systems where the variable background source is multiply-imaged by a massive galaxy in the foreground, provide direct measurements of cosmological distance that are very complementary to other cosmographic probes. The success of the technique depends on the availability and size of a suitable sample of lensed quasars or supernovae, precise measurements of the time delays, accurate modeling of the gravitational potential of the main deflector, and our ability to characterize the distribution of mass along the line of sight to the source. We review the progress made during the last 15 years, during which the first competitive cosmological inferences with time delays were made, and look ahead to the potential of significantly larger lens samples in the near future.

  10. History, biological effects, and dosimetry of beta radiation

    International Nuclear Information System (INIS)

    There has been a renewed interest in the dosimetry of beta radiation, particularly in the nuclear power industry. This interest is fueled by the current regulatory concern over exposure to hot particles. Hot particles are small, usually microscopic particles of fuel material or activated products produced as a result of neutron activation in a nuclear reactor. In addition, these particles are characterized as having very high specific activity and being composed primarily of beta-emitting radionuclides. Of primary interest in the dosimetry of hot particles is the absorbed dose and/or dose equivalent to the basal layer of the skin. Current federal regulations, as well as international and national radiation protection standards, do not address adequately the exposure of small areas of the skin from a single point source. In this paper, the history of beta dosimetry is reviewed with an emphasis on early beta-radiation exposures, such as those associated with fallout from nuclear weapons. Beta burns due to the black rain associated with the Japanese bombings and fallout studies at the Nevada test site and in the Pacific testing area provided much of the earliest data. Many survivors of the Japanese bombings were exposed to high-intensity beta radiation when they were caught in a rainout of material that had been sucked up into the fireball of the weapon

  11. Approximation of distributed delays

    CERN Document Server

    Lu, Hao; Eberard, Damien; Simon, Jean-Pierre

    2010-01-01

    We address in this paper the approximation problem of distributed delays. Such elements are convolution operators with kernel having bounded support, and appear in the control of time-delay systems. From the rich literature on this topic, we propose a general methodology to achieve such an approximation. For this, we enclose the approximation problem in the graph topology, and work with the norm defined over the convolution Banach algebra. The class of rational approximates is described, and a constructive approximation is proposed. Analysis in time and frequency domains is provided. This methodology is illustrated on the stabilization control problem, for which simulations results show the effectiveness of the proposed methodology.

  12. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne;

    2011-01-01

    -stage procedures. From the Danish Registry for Plastic Surgery of the Breast, which has prospectively registered data for women undergoing breast implantations since 1999, we identified 559 women without a history of radiation therapy undergoing 592 delayed breast reconstructions following breast cancer during the......Studies of complications following reconstructive surgery with implants among women with breast cancer are needed. As the, to our knowledge, first prospective long-term study we evaluated the occurrence of complications following delayed breast reconstruction separately for one- and two...

  13. Double beta decay experiments

    OpenAIRE

    Barabash, A. S.

    2011-01-01

    The present status of double beta decay experiments is reviewed. The results of the most sensitive experiments are discussed. Proposals for future double beta decay experiments with a sensitivity to the $$ at the level of (0.01--0.1) eV are considered.

  14. Negative Beta Encoder

    CERN Document Server

    Kohda, Tohru; Aihara, Kazuyuki

    2008-01-01

    A new class of analog-digital (A/D), digital-analog (D/A) converters as an alternative to conventional ones, called $\\beta$-encoder, has been shown to have exponential accuracy in the bit rates while possessing self-correction property for fluctuations of amplifier factor $\\beta$ and quantizer threshold $\

  15. Betting against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    2014-01-01

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model's five central predictions: (1) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for...

  16. Asynchronous Bounded Expected Delay Networks

    OpenAIRE

    Bakhshi, Rena; Endrullis, Jörg; Fokkink, Wan; Pang, Jun

    2010-01-01

    The commonly used asynchronous bounded delay (ABD) network models assume a fixed bound on message delay. We propose a probabilistic network model, called asynchronous bounded expected delay (ABE) model. Instead of a strict bound, the ABE model requires only a bound on the expected message delay. While the conditions of ABD networks restrict the set of possible executions, in ABE networks all asynchronous executions are possible, but executions with extremely long delays are less probable. In ...

  17. Development of a three-layer phoswich alpha-beta-gamma imaging detector

    Science.gov (United States)

    Yamamoto, Seiichi; Ishibashi, Hiroyuki

    2015-06-01

    For radiation monitoring at the sites of such nuclear power plant accidents as Fukushima Daiichi, radiation detectors are needed not only for gamma photons but also for alpha and beta particles because some nuclear fission products emit beta particles and gamma photons and some nuclear fuels contain plutonium that emits alpha particles. In some applications, imaging detectors are required to detect the distribution of plutonium particles that emit alpha particles and radiocesium in foods that emits beta particles and gamma photons. To solve these requirements, we developed an imaging detector that can measure the distribution of alpha and beta particles as well as gamma photons. The imaging detector consists of three-layer scintillators optically coupled to each other and to a position sensitive photomultiplier tube (PSPMT). The first layer, which is made of a thin plastic scintillator (decay time: ~5 ns), detects alpha particles. The second layer, which is made of a thin Gd2SiO5 (GSO) scintillator with 1.5 mol% Ce (decay time: 35 ns), detects beta particles. The third layer made of a thin GSO scintillator with 0.4 mol% Ce (decay time: 70 ns) detects gamma photons. Using pulse shape discrimination, the images of these layers can be separated. The position information is calculated by the Anger principle from 8×8 anode signals from the PSPMT. The images for the alpha and beta particles and the gamma photons are individually formed by the pulse shape discriminations for each layer. We detected alpha particle images in the first layer and beta particle images in the second layer. Gamma photon images were detected in the second and third layers. The spatial resolution for the alpha and beta particles was ~1.25 mm FWHM and less than 2 mm FWHM for the gamma photons. We conclude that our developed alpha-beta-gamma imaging detector is promising for imaging applications not only for the environmental monitoring of radionuclides but also for medical and molecular imaging.

  18. Delayed traumatic diaphragmatic hernia

    Science.gov (United States)

    Lu, Jing; Wang, Bo; Che, Xiangming; Li, Xuqi; Qiu, Guanglin; He, Shicai; Fan, Lin

    2016-01-01

    Abstract Background: Traumatic diaphragmatic hernias (TDHs) are sometimes difficult to identify at an early stage and can consequently result in diagnostic delays with life-threatening outcomes. It is the aim of this case study to highlight the difficulties encountered with the earlier detection of traumatic diaphragmatic hernias. Methods: Clinical data of patients who received treatment for delayed traumatic diaphragmatic hernias in registers of the First Affiliated Hospital of Xi’an Jiaotong University from 1998 to 2014 were analyzed retrospectively. Results: Six patients were included in this study. Left hemidiaphragm was affected in all of them. Most of the patients had a history of traffic accident and 1 a stab-penetrating injury. The interval from injury to developing symptoms ranged from 2 to 11 years (median 5 years). The hernial contents included the stomach, omentum, small intestine, and colon. Diaphragmatic injury was missed in all of them during the initial managements. All patients received operations once the diagnosis of delayed TDH was confirmed, and no postoperative mortality was detected. Conclusions: Delayed TDHs are not common, but can lead to serious consequences once occurred. Early detection of diaphragmatic injuries is crucial. Surgeons should maintain a high suspicion for injuries of the diaphragm in cases with abdominal or lower chest traumas, especially in the initial surgical explorations. We emphasize the need for radiographical follow-up to detect diaphragmatic injuries at an earlier stage. PMID:27512848

  19. Speech and Language Delay

    Science.gov (United States)

    ... child depends on the cause of the speech delay. Your doctor will tell you the cause of your child's problem and explain any treatments that might fix the problem or make it better. A speech and language pathologist might be helpful in making treatment plans. This ...

  20. Rapid synthesis of beta zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

    2015-08-18

    The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

  1. Interferometric Propagation Delay

    Science.gov (United States)

    Goldstein, Richard

    1999-01-01

    Radar interferometry based on (near) exact repeat passes has lately been used by many groups of scientists, worldwide, to achieve state of the art measurements of topography, glacier and ice stream motion, earthquake displacements, oil field subsidence, lava flows, crop-induced surface decorrelation, and other effects. Variations of tropospheric and ionospheric propagation delays limit the accuracy of all such measurements. We are investigating the extent of this limitation, using data from the Shuttle radar flight, SIR-C, which is sensitive to the troposphere, and the Earth Resources Satellites, ERS-1/2, which are sensitive to both the troposphere and the ionosphere. We are presently gathering statistics of the delay variations over selected, diverse areas to determine the best accuracy possible for repeat track interferometry. The phases of an interferogram depend on both the topography of the scene and variations in propagation delay. The delay variations can be caused by movement of elements in the scene, by changes in tropospheric water vapor and by changes of the charge concentrations in the ionosphere. We plan to separate these causes by using the data from a third satellite visit (three-pass interferometry). The figure gives the geometry of the three-pass observations. The page of the figure is taken to be perpendicular to the spacecraft orbits. The three observational locations are marked on the figure, giving baselines B-12 and B-13, separated by the angle alpha. These parameters are almost constant over the whole scene. However, each pixel has an individual look angle, theta, which is related to the topography, rho is the slant range. A possible spurious time delay is shown. Additional information is contained in the original.

  2. Calibration of beta dosimeter and personal dosimeter

    International Nuclear Information System (INIS)

    This paper introduces ISO standard ISO 6980 which prepared especially for the calibration of beta dosimeter and personal dosimeter. The standard has three aspects including method of production of reference beta particle radiations, calibration fundamentals related to basic quantities characterizing the radiation field, and calibration of area and personal dosemters and the determination of their response as a function of beta radiation energy and angle of incidence. Here particular emphasis is placed on the determination of basic quantity of tissue absorbed dose at a depth of 0.07 mm in the tissue slab phantom and calibration procedure by mean of the calibration quantity of directional dose equivalent H'(0.07, Ω) and personal dose equivalent Hp (0.07, Ω). Finally, combined standard uncertainty for the determination of absorbed dose rate and component uncertainties of calibration is given as examples. (authors)

  3. Power output and efficiency of beta-emitting microspheres

    Science.gov (United States)

    Cheneler, David; Ward, Michael

    2015-01-01

    Current standard methods to calculate the dose of radiation emitted during medical applications by beta-minus emitting microspheres rely on an over-simplistic formalism. This formalism is a function of the average activity of the radioisotope used and the physiological dimensions of the patient only. It neglects the variation in energy of the emitted beta particle due to self-attenuation, or self-absorption, effects related to the finite size of the sphere. Here it is assumed the sphere is comprised of a pure radioisotope with beta particles being emitted isotropically throughout the material. The full initial possible kinetic energy distribution of a beta particle is taken into account as well as the energy losses due to scattering by other atoms in the microsphere and bremsstrahlung radiation. By combining Longmire's theory of the mean forward range of charged particles and the Rayleigh distribution to take into account the statistical nature of scattering and energy straggling, the linear attenuation, or self-absorption, coefficient for beta-emitting radioisotopes has been deduced. By analogy with gamma radiation transport in spheres, this result was used to calculate the rate of energy emitted by a beta-emitting microsphere and its efficiency. Comparisons to standard point dose kernel formulations generated using Monte Carlo data show the efficacy of the proposed method. Yttrium-90 is used as a specific example throughout, as a medically significant radioisotope, frequently used in radiation therapy for treating cancer.

  4. Expression and functional importance of collagen-binding integrins, alpha 1 beta 1 and alpha 2 beta 1, on virus-activated T cells

    DEFF Research Database (Denmark)

    Andreasen, Susanne Ø; Thomsen, Allan R; Koteliansky, Victor E; Novobrantseva, Tatiana I; Sprague, Andrew G; de Fougerolles, Antonin R; Christensen, Jan P

    2003-01-01

    Adhesive interactions are crucial to cell migration into inflammatory sites. Using murine lymphocytic choriomeningitis virus as an Ag model system, we have investigated expression and function of collagen-binding integrins, alpha(1)beta(1) and alpha(2)beta(1), on activated and memory T cells. Using...... this system and MHC tetramers to define Ag-specific T cells, we demonstrate that contrary to being VLAs, expression of alpha(1)beta(1) and alpha(2)beta(1) can be rapidly induced on acutely activated T cells, that expression of alpha(1)beta(1) remains elevated on memory T cells, and that expression of...... alpha(1)beta(1) parallels that of viral-specific effector CD8(+) T cells (defined by tetramer and IFN-gamma staining). In an adoptive transfer model, mAb-mediated blockade of these integrins on activated effector and memory T cells inhibited Ag-specific delayed-type hypersensitivity responses; similar...

  5. Optimum Delayed Retirement Credit

    OpenAIRE

    Sheshinski, Eytan

    2002-01-01

    A central question for pension design is how benefits should vary with the age of retirement beyond early eligibility age. It is often argued that in order to be neutral with respect to individual retirement decisions benefits should be actuarially fair, that is, the present value of additional contributions and benefits (’Delayed Retirement Credit’ - DRC) due to postponed retirement should be equal. We show that in a self-selection, asymmetric information model, because individual decisions ...

  6. Delay reduction: current status.

    OpenAIRE

    Fantino, E; Preston, R. A.; Dunn, R

    1993-01-01

    Delay-reduction theory states that the effectiveness of a stimulus as a conditioned reinforcer may be predicted most accurately by the reduction in time to primary reinforcement correlated with its onset. We review support for the theory and then discuss two new types of experiments that assess it. One compares models of choice in situations wherein the less preferred outcome is made more accessible; the other investigates whether frequency of conditioned reinforcement affects choice beyond t...

  7. Beta-decay of the N=Z nucleus 72Kr

    International Nuclear Information System (INIS)

    The beta-decay of the N = Z, even-even nucleus 72Kr has been studied at the ISOLDE PSB facility at CERN. Measurements of βγ and βγγ coincidences have enriched the decay scheme of the daughter nucleus 72Br with 27 new low spin levels. A more precise half-life of T1/2 = 17.1(2) s has been determined. Strong feeding to the 72Br ground state is established yielding an unambiguous Jπ = 1+ assignment for this state. Candidates for the 72Br g.s. wave function are discussed in the framework of a self-consistent deformed mean-field calculation with SG2 Skyrme force and pairing correlations. A search for beta-delayed particle emission was made and an upper limit of 10-6 for this decay branch obtained. The cumulated experimental level density of 1+ states has been fitted with the constant temperature formula. The comparison indicates that most likely all 1+ levels up to 1.2 MeV have been observed in this investigation. The corresponding nearest-neighbour level spacing does not follow a Poisson distribution. The Gamow-Teller strength distribution is compared, in terms of nuclear deformation, with different calculations made in the framework of the quasiparticle random phase approximation. (orig.)

  8. Measurement of beta decay periods for Fe-Ni neutrons rich isotopes

    International Nuclear Information System (INIS)

    Thermal fission of 239 Pu was used to produce 68,69 Co and 68 Fe isotopes, the lightest ones ever observed in thermal fission, at the ILL high-flux reactor, in Grenoble. Separated with the Lohengrin recoil spectrometer, then identified by means of a Δ E-E ionization chamber, fragments were implanted in a set of Si-detectors, where β-particles were detected too. The fission yields were determined, and the beta-decay half-lives were extracted from delayed coincidence analysis between ion implantation and the subsequent beta detection: They were found to be 0.27±0.05s, 0.18±0.10s, and 0.10±0.06s respectively for 69 Co, 68 Co, and 68 Fe. This method was adapted to a new experimental configuration: 65 Fe isotopes were produced from 86 Kr projectile fragmentation at 500 MeV/u on a Be target. Selected ions were separated with the fragment separator FRS at GSI (Darmstadt), tuned in the monoenergetic mode. Fragments were identified by ΔE-ToF, slowed down, and then implanted in two rows of PIN-diodes that provided an additional range selection. The half-life were determined from the analysis of the decay chain Fe-Co-Ni: it was found 0.4±0.2s. Production rates obtained with the two methods are compared at the end of this work

  9. Beta-carotene

    Science.gov (United States)

    ... and deterioration of the lining of the mouth (oral mucositis). Taking beta-carotene by mouth doesn’t appear to prevent the development of oral mucositis during radiation therapy or chemotherapy. Pancreatic cancer. Taking ...

  10. Neutrinoless double beta decay

    International Nuclear Information System (INIS)

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given. (author)

  11. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  12. Time-Delay Interferometry

    Directory of Open Access Journals (Sweden)

    Massimo Tinto

    2014-08-01

    Full Text Available Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI. This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

  13. Time-Delay Interferometry

    Science.gov (United States)

    Dhurandhar, Sanjeev V.; Tinto, Massimo

    2005-07-01

    Equal-arm interferometric detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers), the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called Time-Delay Interferometry (TDI). This article provides an overview of the theory and mathematical foundations of TDI as it will be implemented by the forthcoming space-based interferometers such as the Laser Interferometer Space Antenna (LISA) mission. We have purposely left out from this first version of our "Living Review" article on TDI all the results of more practical and experimental nature, as well as all the aspects of TDI that the data analysts will need to account for when analyzing the LISA TDI data combinations. Our forthcoming "second edition" of this review paper will include these topics.

  14. Neutrinoless beta-beta matrix element of 76Ge from spectroscopic data

    CERN Document Server

    Suhonen, J

    2008-01-01

    In this work we use the recently measured neutron pairing correlations in the 76Ge and 76Se nuclei as a guideline to adjust the single-particle energies in the 1p0f0g shell. The resulting BCS occupations reproduce the measured pairing data. The proton energies were inspected by using the odd-mass nuclei adjacent to 76Ge and 76Se as spectroscopic tools. The nuclear matrix element of the neutrinoless double beta (0-nu-beta-beta) decay of 76Ge is calculated in this fitted single-particle basis by using the proton-neutron quasiparticle random-phase approximation (pnQRPA) in a realistic model space and by adopting effective microscopic two-nucleon interactions. We include the nucleon-nucleon short-range correlations and other relevant corrections at the nucleon level. It is found that the resulting 0-nu-beta-beta matrix element is smaller than in the previous pnQRPA calculations, and closer to the recently reported shell-model results.

  15. [High beta tokamak research

    International Nuclear Information System (INIS)

    Our activities on High Beta Tokamak Research during the past 20 months of the present grant period can be divided into six areas: reconstruction and modeling of high beta equilibria in HBT; measurement and analysis of MHD instabilities observed in HBT; measurements of impurity transport; diagnostic development on HBT; numerical parameterization of the second stability regime; and conceptual design and assembly of HBT-EP. Each of these is described in some detail in the sections of this progress report

  16. High beta multipoles

    International Nuclear Information System (INIS)

    Multipoles are being employed as devices to study fusion issues and plasma phenomena at high values of beta (plasma pressure/magnetic pressure) in a controlled manner. Due to their large volume, low magnetic field (low synchrotron radiation) region, they are also under consideration as potential steady state advanced fuel (low neutron yield) reactors. Present experiments are investigating neoclassical (bootstrap and Pfirsch-Schlueter) currents and plasma stability at extremely high beta

  17. Autoregressive conditional beta

    OpenAIRE

    Yunmi Kim

    2012-01-01

    The capital asset pricing model provides various predictions about equilibrium expected returns on risky assets. One key prediction is that the risk premium on a risky asset is proportional to the nondiversifiable market risk measured by the asset's beta coefficient. This paper proposes a new method for estimating and drawing inferences from a time-varying capital asset pricing model. The proposed method, which can be considered a vector autoregressive model for multiple beta coefficients, is...

  18. A proposed resolution of the delayed-choice paradox

    OpenAIRE

    Heaney, Michael B.

    2014-01-01

    This paper proposes a resolution of the delayed-choice paradox of the Conventional Theory of quantum mechanics, where a particle seems to know what will happen in the future, and changes its present behavior accordingly. A comparison of the Conventional Theory with an Advanced Theory and a Symmetrical Theory of the same delayed-choice experiment suggests that the apparent paradox is caused by an incorrect assumption about the interaction of a wavefunction with a beam-splitter. Once this assum...

  19. Current Vaccine Shortages and Delays

    Science.gov (United States)

    ... CDC.gov . Vaccines and Immunizations Share Compartir Current Vaccine Shortages & Delays Last Updated December 7, 2015 On ... schedule are included in this update. Chart of Vaccines* in Delay or Shortage Vaccines are listed in ...

  20. NEUTRINOLESS DOUBLE BETA DECAY: AN EXTREME CHALLENGE

    OpenAIRE

    Fernando Ferroni

    2013-01-01

    Neutrino-less Double Beta Decay is the only known way to possibly resolve the nature of neutrino mass. The chances to cover the mass region predicted by the inverted hierarchy require a step forward in detector capability. A possibility is to make use of scintillating bolometers. These devices shall have a great power in distinguishing signals from alfa particles from those induced by electrons. This feature might lead to an almost background-free experiment. Here the Lucifer concept will be ...

  1. Beta attenuation transmission system (BATS)

    International Nuclear Information System (INIS)

    The beta attenuation transmission system (BATS) is an automated radiation gauge designed for quantitative measurement of component thickness in explosive detonators. The BATS was designed and built by Group M-1, the Nondestructive Testing Group, of the Los Alamos Scientific Laboratory to measure the areal thickness, in mg/cm2, of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A 90Sr source is collimated by a 0.25 x 1.59-mm slit, and the transmitted beta-particle flux is detected by a plastic scintillator, coupled to a photomultiplier tube. The detonator is transported through the radiation beam by a leadscrew, ballnut, stepping-motor combination. Continuous analog position data are available, derived from the output from a linear-actuated potentiometer attached to the scanner. A linear electrometer amplifies the detected signal, which is then integrated for a preselected time, to obtain the desired statistical accuracy. A microprocessor (μP) is used to control the scanner position and to make the data readings at the assigned positions. The data are stored, and, at the completion of the scan, are processed into the desired format. The final answer is displayed to the operator or output to a peripheral device for permanent record. The characteristics of the radiation source, the collimator, the signal detection and conditioning, and the final results are described in detail. The scanner and the microprocessor control system are briefly outlined

  2. Beta attenuation transmission system (BATS)

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, R.C.; Fullbright, H.J.

    1977-01-01

    The beta attenuation transmission system (BATS) is an automated radiation gauge designed for quantitative measurement of component thickness in explosive detonators. The BATS was designed and built by Group M-1, the Nondestructive Testing Group, of the Los Alamos Scientific Laboratory to measure the areal thickness, in mg/cm/sup 2/, of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A /sup 90/Sr source is collimated by a 0.25 x 1.59-mm slit, and the transmitted beta-particle flux is detected by a plastic scintillator, coupled to a photomultiplier tube. The detonator is transported through the radiation beam by a leadscrew, ballnut, stepping-motor combination. Continuous analog position data are available, derived from the output from a linear-actuated potentiometer attached to the scanner. A linear electrometer amplifies the detected signal, which is then integrated for a preselected time, to obtain the desired statistical accuracy. A microprocessor (..mu..P) is used to control the scanner position and to make the data readings at the assigned positions. The data are stored, and, at the completion of the scan, are processed into the desired format. The final answer is displayed to the operator or output to a peripheral device for permanent record. The characteristics of the radiation source, the collimator, the signal detection and conditioning, and the final results are described in detail. The scanner and the microprocessor control system are briefly outlined.

  3. A system for simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, A. T.; Hamby, D. M.

    2007-08-01

    A state-of-the-art radiation detection system for real-time and simultaneous spectroscopy of beta-particles and gamma-rays has been developed. The system utilizes a triple-layer phoswich detector and a customized Digital Pulse Processor (DPP) designed and built in our laboratory. The DPP board digitally captures the analog signal pulses and, following several digital preprocessing steps, transfers valid pulses to the host computer for further digital processing. A resolving algorithm also was developed to digitally discriminate beta and gamma events, and reconstruct separate beta and gamma-ray energy spectra with minimal crosstalk. The spectrometer has proven to be an effective tool for recording separate beta and gamma-ray spectra from mixed radiation fields. The system as a beta-gamma spectrometer will have broad-ranging applications in nuclear non-proliferation, radioactive waste management, worker safety, systems reliability, dose assessment, and risk analysis.

  4. Statistical multimoment bifurcations in random-delay coupled swarms

    Science.gov (United States)

    Mier-y-Teran-Romero, Luis; Lindley, Brandon; Schwartz, Ira B.

    2012-11-01

    We study the effects of discrete, randomly distributed time delays on the dynamics of a coupled system of self-propelling particles. Bifurcation analysis on a mean field approximation of the system reveals that the system possesses patterns with certain universal characteristics that depend on distinguished moments of the time delay distribution. Specifically, we show both theoretically and numerically that although bifurcations of simple patterns, such as translations, change stability only as a function of the first moment of the time delay distribution, more complex patterns arising from Hopf bifurcations depend on all of the moments.

  5. Imaging alpha particle detector

    Science.gov (United States)

    Anderson, D.F.

    1980-10-29

    A method and apparatus for detecting and imaging alpha particles sources is described. A dielectric coated high voltage electrode and a tungsten wire grid constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source to be quantitatively or qualitatively analyzed. A thin polyester film window allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

  6. Precision beta gauge using a plastic scintillator and photomultiplier detector

    Energy Technology Data Exchange (ETDEWEB)

    Jaklevic, J.M.; Madden, N.W.; Wiegand, C.E. (Lawrence Berkely Lab., CA (USA))

    1983-09-01

    We describe the use of a plastic scintillator photomultiplier detector combination in applications involving the precision beta-gauge measurements of small mass deposits of thin substrates. The requisite precision (+- 2 ..mu..g/cm/sup 2/) places stringent requirements on the beta-particle counter and associated electronics. The scintillator based system is shown to be equivalent if not superior to previously employed semiconductor detectors with respect to long-term counting stability.

  7. Neutron resonance study of a delayed neutron emitter, /sup 87/Kr

    CERN Document Server

    Fogelberg, B; Macklin, R L; Raman, S; Stelson, P H

    1981-01-01

    The unbound levels in /sup 87/Kr have been studied as neutron resonances up to 400 keV neutron energy at the ORELA linear electron accelerator. The observed p-wave resonances, with I/sup pi /=1/2/sup - / and 3/2/sup -/ can also be populated in the beta -decay of the 3/2 /sup -/ ground state of /sup 87/Br. When comparing the present results with previous studies of beta -delayed neutron spectra, the authors find that almost all observed p-wave resonances can be identified with peaks in the delayed neutron spectra. (0 refs).

  8. Time-Delay Interferometry

    Directory of Open Access Journals (Sweden)

    Dhurandhar Sanjeev V.

    2005-07-01

    Full Text Available Equal-arm interferometric detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called Time-Delay Interferometry (TDI. This article provides an overview of the theory and mathematical foundations of TDI as it will be implemented by the forthcoming space-based interferometers such as the Laser Interferometer Space Antenna (LISA mission. We have purposely left out from this first version of our "Living Review" article on TDI all the results of more practical and experimental nature, as well as all the aspects of TDI that the data analysts will need to account for when analyzing the LISA TDI data combinations. Our forthcoming "second edition" of this review paper will include these topics.

  9. Scalar-mediated double beta decay and LHC

    CERN Document Server

    Gonzales, L; Hirsch, M; Kovalenko, S G

    2016-01-01

    The decay rate of neutrinoless double beta decay could be dominated by short-range diagrams involving heavy scalar particles ("topology-II" diagrams). Examples are diagrams with diquarks, leptoquarks or charged scalars. Here, we compare the discovery potential for lepton number violating signals at the LHC with constraints from dijet and leptoquark searches and the sensitivity of double beta decay experiments, using three example models. We note that already with 20/fb the LHC will test interesting parts of the parameter space of these models, not excluded by current limits on double beta decay.

  10. Vehicle barrier with access delay

    Science.gov (United States)

    Swahlan, David J; Wilke, Jason

    2013-09-03

    An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

  11. Concurrent Delay in Construction Disputes

    DEFF Research Database (Denmark)

    Cavaleri, Sylvie Cécile

    Delay is one of the issues most frequently encountered in today’s construction industry; it causes significant economic damage to all parties involved. Construction contracts, standard and bespoke, almost invariably consider delay from a perspective of single liability. If the event causing the...... period of delay can potentially be attributed to several events falling within both parties' spheres of responsibility, commonly termed concurrent delay, is rarely regulated in construction contracts in spite of its common occurrence. This book analyses both the theoretical foundations and the practical...... solutions to the issue of concurrent delay in a comparative perspective between common and civil law systems, with an emphasis on Danish and English law....

  12. Contribution of beta 1- and beta 2-adrenoceptors of human atrium and ventricle to the effects of noradrenaline and adrenaline as assessed with (-)-atenolol.

    OpenAIRE

    Lemoine, H.; Schönell, H.; Kaumann, A. J.

    1988-01-01

    1. (-)-Atenolol was used as a tool to assess the function of beta 1- and beta 2-adrenoceptors in human heart. Right atrial and left ventricular preparations from patients undergoing open heart surgery were set up to contract isometrically. Membrane particles were prepared for beta-adrenoceptor labelling with [3H]-(-)-bupranolol and adenylate cyclase assays. 2. The positive inotropic effects of (-)-noradrenaline were antagonized to a similar extent by (-)-atenolol in atrial and ventricular pre...

  13. Delayed appearance of high altitude retinal hemorrhages.

    Directory of Open Access Journals (Sweden)

    Daniel Barthelmes

    Full Text Available BACKGROUND: Retinal hemorrhages have been described as a component of high altitude retinopathy (HAR in association with altitude illness. In this prospective high altitude study, we aimed to gain new insights into the pathophysiology of HAR and explored whether HAR could be a valid early indicator of altitude illness. METHODOLOGY/PRINCIPAL FINDINGS: 28 mountaineers were randomly assigned to two ascent profiles during a research expedition to Mt. Muztagh Ata (7546 m/24,751 ft. Digital fundus photographs were taken prior to expedition at 490 m (1,607 ft, during expedition at 4497 m (14,750 ft = base camp, 5533 m (18,148 ft, 6265 m (20,549 ft, 6865 m (22,517 ft and 4.5 months thereafter at 490 m. Number, size and time of occurrence of hemorrhages were recorded. Oxygen saturation (SpO₂ and hematocrit were also assessed. 79% of all climbers exhibited retinal hemorrhages during the expedition. Number and area of retinal bleeding increased moderately to medium altitudes (6265 m. Most retinal hemorrhages were detected after return to base camp from a high altitude. No post-expeditional ophthalmic sequelae were detected. Significant negative (SpO₂ Beta: -0.4, p<0.001 and positive (hematocrit Beta: 0.2, p = 0.002, time at altitude Beta: 0.33, p = 0.003 correlations with hemorrhages were found. CONCLUSIONS/SIGNIFICANCE: When closely examined, a very large amount of climbers exhibit retinal hemorrhages during exposure to high altitudes. The incidence of retinal hemorrhages may be greater than previously appreciated as a definite time lag was observed between highest altitude reached and development of retinal bleeding. Retinal hemorrhages should not be considered warning signs of impending severe altitude illness due to their delayed appearance.

  14. Covalent and heterosupramolecular interaction of ceramic particles

    OpenAIRE

    Stieger, Gregor

    2002-01-01

    New concepts of particle interaction for the processing of ceramic powders are developed. They are based on chemical reactions either by heterosupramolecular or covalent interaction of proper reactants. For this the particles are functionalized so that they are able to undergo defined reactions with each other. A commercially available beta-cyclodextrin derivative, 3-chlor-5-sodium-hydroxyl-trianzinyl-beta-cyclodextrin, is covalently bound to the Si3N4 surface in an one step reaction. An effo...

  15. Delayed-choice gedanken experiments and their realizations

    Science.gov (United States)

    Ma, Xiao-song; Kofler, Johannes; Zeilinger, Anton

    2016-01-01

    The wave-particle duality dates back to Einstein's explanation of the photoelectric effect through quanta of light and de Broglie's hypothesis of matter waves. Quantum mechanics uses an abstract description for the behavior of physical systems such as photons, electrons, or atoms. Whether quantum predictions for single systems in an interferometric experiment allow an intuitive understanding in terms of the particle or wave picture depends on the specific configuration which is being used. In principle, this leaves open the possibility that quantum systems always behave either definitely as a particle or definitely as a wave in every experimental run by a priori adapting to the specific experimental situation. This is precisely what is tried to be excluded by delayed-choice experiments, in which the observer chooses to reveal the particle or wave character of a quantum system—or even a continuous transformation between the two—at a late stage of the experiment. The history of delayed-choice gedanken experiments, which can be traced back to the early days of quantum mechanics, is reviewed. Their experimental realizations, in particular, Wheeler's delayed choice in interferometric setups as well as delayed-choice quantum erasure and entanglement swapping are discussed. The latter is particularly interesting, because it elevates the wave-particle duality of a single quantum system to an entanglement-separability duality of multiple systems.

  16. The Fas pathway is involved in pancreatic beta cell secretory function

    DEFF Research Database (Denmark)

    Schumann, Desiree M; Maedler, Kathrin; Franklin, Isobel;

    2007-01-01

    Pancreatic beta cell mass and function increase in conditions of enhanced insulin demand such as obesity. Failure to adapt leads to diabetes. The molecular mechanisms controlling this adaptive process are unclear. Fas is a death receptor involved in beta cell apoptosis or proliferation, depending...... on the activity of the caspase-8 inhibitor FLIP. Here we show that the Fas pathway also regulates beta cell secretory function. We observed impaired glucose tolerance in Fas-deficient mice due to a delayed and decreased insulin secretory pattern. Expression of PDX-1, a beta cell......-specific transcription factor regulating insulin gene expression and mitochondrial metabolism, was decreased in Fas-deficient beta cells. As a consequence, insulin and ATP production were severely reduced and only partly compensated for by increased beta cell mass. Up-regulation of FLIP enhanced NF-kappaB activity via...

  17. Beta decay properties from a statistical model

    International Nuclear Information System (INIS)

    The present work assumes that any intrinsic structure in the nuclei involved is not important. Only spin, parity, and energy are considered. Quantities such as half-life, average beta energy, or average gamma energy can be obtained by integrals over the beta strength function weighted by kinematic and other factors. The beta strength function is proportional to the level density multiplied by a reduced transition probability. Delayed neutron emission is calculated by assuming that the daughter is a compound nucleus which then statistically decays as in the Hauser-Feshbach approach. Using the ENDF/B-V fission product file which contains 877 nuclei, energy-dependent reduced transition probabilities were found for allowed 0+ → 1+ transitions (50 cases) and for other allowed transitions (over 600 cases), corresponding to log ft values of 4.3 and 5.6 respectively. No dependence on either transition energy or on mass was found. A reduced transition probability corresponding to log ft of 7.1 was used for first forbidden transitions. Some results are presented and discussed

  18. Thermoluminescent dosimeter-direct reading dosimeter dose discrepancy: studies on the role of beta radiation fields

    International Nuclear Information System (INIS)

    Dosimetry studies pertaining to thermoluminescent dosimeter (TLD) and direct reading dosimeter (DRD) have been performed for photons, beta fields and mixed field of photons and beta particles. In lab conditions, for pure photon radiation fields, the doses estimated using DRD and TLD match within the acceptable limits whereas in the mixed fields of photons and high energy beta particles, it has been found that the DRD doses are always higher than the corresponding whole body doses estimated by the TLD. This is due to the fact that DRD responds to high energy beta particles and the typical response of the DRD to high energy beta particles is observed to be in the range of 15-30%. This may lead to TLD-DRD dose discrepancy at workplaces where the skin doses received by the radiation workers from high energy beta sources in a given monitoring period are significant. The paper also provides a comparison of three different TLD-DRD discrepancy identification criteria available in literature for exposure conditions with a significant dose due to beta radiations. In addition, estimate of threshold beta dose which may lead to discrepancy as per the criteria have been studied. The results reported in this paper would be helpful in understanding the discrepancy arising out of variable response of DRD to beta radiations and will be useful in resolving the discrepancy in such cases. (author)

  19. Double beta decay experiments

    International Nuclear Information System (INIS)

    The great sensitivity of double beta decay to neutrino mass and right handed currents has motivated many new and exciting attempts to observe this elusive nuclear phenomenon directly. Experiments in operation and other coming on line in the next one or two years are expected to result in order-of-magnitude improvements in detectable half lives for both the two-neutrino and no-neutrino modes. A brief history of double beta decay experiments is presented together with a discussion of current experimental efforts, including a gas filled time projection chamber being used to study selenium-82. (author)

  20. Plasma beta HCG determination

    International Nuclear Information System (INIS)

    There are three important indications for the early diagnosis of pregnancy through the determination of the beta sub-unit of chorionic gonadotrophin using radioimmunoassay: 1) some patient's or doctor's anxiety to discover the problem; 2) when it will be necessary to employ diagnostic or treatment procedures susceptible to affect the ovum; and 3) in the differential diagnosis of amenorrhoea, uterine hemorrhage and abdominal tumors. Other user's are the diagnosis of missed absortion, and the diagnosis and follow-up of chrorioncarcinoma. The AA. studied 200 determinations of plasma beta-HCG, considering the main difficulties occuring in the clinical use of this relevant laboratory tool in actual Obstetrics. (author)

  1. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.;

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions of...... differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears that the...

  2. Particle Pollution

    Science.gov (United States)

    ... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...

  3. Synchronizing time delay systems using variable delay in coupling

    International Nuclear Information System (INIS)

    Highlights: → Delay and anticipation in coupling function varies with system dynamics. → Delay or anticipation of the synchronized state is independent of system delay. → Stability analysis developed is quite general. → We demonstrate enhanced security in communication. → Generalized synchronization possible over a wide range of parameter mismatch. - Abstract: We present a mechanism for synchronizing time delay systems using one way coupling with a variable delay in coupling that is reset at finite intervals. We present the analysis of the error dynamics that helps to isolate regions of stability of the synchronized state in the parameter space of interest for single and multiple delays. We supplement this by numerical simulations in a standard time delay system like Mackey Glass system. This method has the advantage that it can be adjusted to be delay or anticipatory in synchronization with a time which is independent of the system delay. We demonstrate the use of this method in communication using the bi channel scheme. We show that since the synchronizing channel carries information from transmitter only at intervals of reset time, it is not susceptible to an easy reconstruction.

  4. Re-expression of IGF-II is important for beta cell regeneration in adult mice.

    Directory of Open Access Journals (Sweden)

    Luxian Zhou

    Full Text Available BACKGROUND: The key factors which support re-expansion of beta cell numbers after injury are largely unknown. Insulin-like growth factor II (IGF-II plays a critical role in supporting cell division and differentiation during ontogeny but its role in the adult is not known. In this study we investigated the effect of IGF-II on beta cell regeneration. METHODOLOGY/PRINCIPAL FINDINGS: We employed an in vivo model of 'switchable' c-Myc-induced beta cell ablation, pIns-c-MycER(TAM, in which 90% of beta cells are lost following 11 days of c-Myc (Myc activation in vivo. Importantly, such ablation is normally followed by beta cell regeneration once Myc is deactivated, enabling functional studies of beta cell regeneration in vivo. IGF-II was shown to be re-expressed in the adult pancreas of pIns-c-MycER(TAM/IGF-II(+/+ (MIG mice, following beta cell injury. As expected in the presence of IGF-II beta cell mass and numbers recover rapidly after ablation. In contrast, in pIns-c-MycER(TAM/IGF-II(+/- (MIGKO mice, which express no IGF-II, recovery of beta cell mass and numbers were delayed and impaired. Despite failure of beta cell number increase, MIGKO mice recovered from hyperglycaemia, although this was delayed. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that beta cell regeneration in adult mice depends on re-expression of IGF-II, and supports the utility of using such ablation-recovery models for identifying other potential factors critical for underpinning successful beta cell regeneration in vivo. The potential therapeutic benefits of manipulating the IGF-II signaling systems merit further exploration.

  5. Radiation synthesis of gelatin/CM-chitosan/{beta}-tricalcium phosphate composite scaffold for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Ying [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Xu Ling, E-mail: lingxu@pku.edu.cn [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang Xiangmei; Zhao Yinghui [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wei Shicheng, E-mail: sc-wei@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Zhai Maolin [Beijing National Laboratory for Molecular Sciences, Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2012-05-01

    A series of biodegradable composite scaffolds was fabricated from an aqueous solution of gelatin, carboxymethyl chitosan (CM-chitosan) and {beta}-tricalcium phosphate ({beta}-TCP) by radiation-induced crosslinking at ambient temperature. Ultrasonic treatment on the polymer solutions significantly influenced the distribution of {beta}-TCP particles. An ultrasonic time of 20 min, followed by 30 kGy irradiation induced a crosslinked scaffold with homogeneous distribution of {beta}-TCP particles, interconnected porous structure, sound swelling capacity and mechanical strength. Fourier Transform Infrared Spectroscopy and X-ray Diffraction analysis indicated that {beta}-TCP successfully incorporated with the network of gelatin and CM-chitosan. In vivo implantation of the scaffold into the mandible of beagle dog revealed that the scaffolds had excellent biocompatibility and the presence of {beta}-TCP can accelerate bone regeneration. The comprehensive results of this study paved way for the application of gelatin/CM-chitosan/{beta}-TCP composite scaffolds as candidate of bone tissue engineering material. - Highlights: Black-Right-Pointing-Pointer Radiation induced a crosslinked scaffold with interconnected porous structure. Black-Right-Pointing-Pointer Ultrasonic time of 20 min led to homogenerously distribution of {beta}-TCP. Black-Right-Pointing-Pointer Increasing amount of {beta}-TCP would restrict the swelling properties. Black-Right-Pointing-Pointer Proper fraction of {beta}-TCP will promote the mechanical properties of the scaffolds. Black-Right-Pointing-Pointer Hybrid of {beta}-TCP promoted the bone regeneration of the mandibles of beagle dogs.

  6. Long delayed radio echoes

    International Nuclear Information System (INIS)

    This thesis describes an experimental program carried out at Stanford over a five-year period. The experiment involved transmitting a radio signal, and tape-recording the output of a receiver gang-tuned with the transmitter for the following 30 s interval. The tapes were later audited for possible LDE. Although none of the possible LDE received reproduces exactly the transmitted signal, many exhibit features that seem unlikely to have been generated except by an LDE mechanism. A mechanism for producing LDE has been studied which involves signal propagation in an electron plasma wave mode at very low group velocity. Modifications to the simplified theory leading to prediction of longer delays are discussed

  7. Evaluation of neutrino masses from $m_{\\beta\\beta}$ values

    CERN Document Server

    Khrushchov, V V

    2008-01-01

    A neutrino mass matrix is considered under conditions of the CP invariance and the negligible reactor mixing $\\theta_{13}$ angle. Absolute mass values for three neutrinos are evaluated in normal and inverted hierarchy spectra on the ground of data for oscillation mixing neutrino parameters and effective neutrino mass entering into a probability of neutrinoless two beta decay $m_{\\beta\\beta}$ values.

  8. Location Estimation using Delayed Measurements

    DEFF Research Database (Denmark)

    Bak, Martin; Larsen, Thomas Dall; Nørgård, Peter Magnus;

    1998-01-01

    When combining data from various sensors it is vital to acknowledge possible measurement delays. Furthermore, the sensor fusion algorithm, often a Kalman filter, should be modified in order to handle the delay. The paper examines different possibilities for handling delays and applies a new techn...... technique to a sensor fusion system for estimating the location of an autonomous guided vehicle. The system fuses encoder and vision measurements in an extended Kalman filter. Results from experiments in a real environment are reported...

  9. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Bennett, Matthew R. [Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77204, USA and Institute of Biosciences and Bioengineering, Rice University, Houston, Texas 77005 (United States); Josić, Krešimir [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204 (United States)

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  10. Time delayed processes in physics, biophysics and archaeology

    CERN Document Server

    Pelc, Magdalena Anna

    2007-01-01

    The motion of particles, where the particles: electrons, ions in microtubules or migrated peoples can be described as the superposition of diffusion and ordered waves. In this paper it is shown that the master equation for transport processes can be formulated as the time delayed hyperbolic partial equation. The equation describes the processes with memory. For characteristic times shorter than the relaxation time the master equation is the generalized Klein - Gordon equation. Key words: hyperbolic transport, microtubules, heat waves, Neolithic migration

  11. Applied Beta Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Rich, B.L.

    1986-01-01

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements.

  12. Roughing up Beta

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Li, Sophia Zhengzi; Todorov, Viktor

    Motivated by the implications from a stylized equilibrium pricing framework, we investigate empirically how individual equity prices respond to continuous, or \\smooth," and jumpy, or \\rough," market price moves, and how these different market price risks, or betas, are priced in the cross-section...

  13. Applied Beta Dosimetry

    International Nuclear Information System (INIS)

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements

  14. Charged-particle activation analysis

    International Nuclear Information System (INIS)

    The paper discusses the methodology and application of nuclear activation with ion beams (19 via 16O(3He,p)18F, 12C(3He,α)11C and 14N(p,α)11C respectively. Recently, triton activation has been shown to be inherently still superior to 3He activation for the determination of oxygen [16O(3H,n)18F]. Lithium, boron, carbon and sulphur can be detected rapidly, nondestructively and with high sensitivity (approximately 0.25ppm for Li and B) via ''quasi-prompt'' activation based on the detection of short-lived, high-energy beta emitters (10ms1H(7Li,n)7Be for example. Nondestructive multielement analysis: Proton activation has the inherent potential for meeting requirements of broad elemental coverage, sensitivity (ppm and sub-ppm range) and selectivity. Up to 30 elements have been determined in Al, Co, Ag, Nb, Rh, Ta and biological samples, using 12-MeV proton activation followed by gamma-ray spectrometry. These capabilities are further enhanced with the counting of X-ray emitters, 28 elements (269) and accuracy using proton activation. 204Pb/206Pb ratios can also be determined with a relative precision of a few per cent. Although charged-particle activation analysis is a well-established trace analysis technique, broad potential capabilities remain to be explored, e.g. those arising from ultrashort-lived nuclides, heavy ion interactions and the combination of delayed and prompt methods. (author)

  15. Interferon Beta-1b Injection

    Science.gov (United States)

    Interferon beta-1b injection is used to reduce episodes of symptoms in patients with relapsing-remitting (course ... and problems with vision, speech, and bladder control). Interferon beta-1b is in a class of medications ...

  16. Genetics Home Reference: beta thalassemia

    Science.gov (United States)

    ... for Disease Control and Prevention Centre for Genetics Education (Australia) Cold Spring Harbor Laboratory: Your Genes Your Health Disease InfoSearch: Beta Thalassemia Genomics Education Programme (UK) MalaCards: dominant beta-thalassemia Merck Manual ...

  17. Final Report for DUSEL R&D: BetaCage: A Screener of Ultra-Low-Level Radioactive Surface Contamination

    Energy Technology Data Exchange (ETDEWEB)

    Golwala, Sunil R. [California Institute of Technology

    2013-12-20

    The eventual full-size, radiopure BetaCage will be a low-background, atmospheric-pressure neon drift chamber with unprecedented sensitivity to emitters of low-energy electrons and alpha particles. We expect that the prototype BetaCage already developed will be an excellent screener of alpha particles. Both the prototype and final BetaCage will provide new infrastructure for rare-event science.

  18. Post-CTS Delay Insertion

    OpenAIRE

    Jianchao Lu; Baris Taskin

    2010-01-01

    A post-clock-tree-synthesis (post-CTS) optimization method is proposed that suggests delay insertion at the leaves of the clock tree in order to implement a limited version of clock skew scheduling. Delay insertion is limited on each clock tree branch simultaneous with a global monitoring of the total amount of delay insertion. The delay insertion for nonzero clock skew operation is performed only at the clock sinks in order to preserve the structure and the optimizations implemented in the c...

  19. Studies of total bremsstrahlung in thick targets of Al, Ti, Sn and Pb for 90Sr beta particles in the photon energy region of 1-100 keV

    Science.gov (United States)

    Singh, Amrit; Dhaliwal, A. S.

    2016-02-01

    Total bremsstrahlung (BS) spectra in thick targets of Al, Ti, Sn and Pb produced by beta emitter 90Sr (End point energy=546 keV) are studied in the photon energy range of 1-100 keV. The experimentally measured BS spectra are compared with the theoretical spectral distributions calculated from Elwert corrected (non relativistic) Bethe-Heitler [EBH] theory, modified Elwert factor (relativistic) Bethe-Heitler [Fmod BH] theory for ordinary bremsstrahlung (OB) and the Avdonina and Pratt [Fmod BH+PB] theory, which include the contribution of polarization bremsstrahlung (PB) into OB. The present results are indicating the correctness of Fmod BH+PB theory in the low energy region, where PB dominates into the BS, but at the middle and higher photon energy region of the bremsstrahlung spectrum, the Fmod BH theory is more close to the experimental results. The description of the bremsstrahlung process in stripped atom (SA) approximation, which indicates the suppression of the bremsstrahlung at higher energy ends due to the production of PB in the low energy region, needs further considerations. Hence, the present measurements for BS for different target materials indicates that the considerations of the screening effects along with other secondary effects during the interaction of incident electrons with the target nuclei are important while describing the production of bremsstrahlung, particularly for the higher energy regions.

  20. Beta decay of the exotic $T_z$ = -2 nuclei $^{48}$Fe, $^{52}$Ni and $^{56}$Zn

    CERN Document Server

    Orrigo, S E A; Fujita, Y; Gelletly, W; Agramunt, J; Algora, A; Ascher, P; Bilgier, B; Blank, B; Cáceres, L; Cakirli, R B; Ganioğlu, E; Gerbaux, M; Giovinazzo, J; Grévy, S; Kamalou, O; Kozer, H C; Kucuk, L; Kurtukian-Nieto, T; Molina, F; Popescu, L; Rogers, A M; Susoy, G; Stodel, C; Suzuki, T; Tamii, A; Thomas, J C

    2016-01-01

    The results of a study of the beta decays of three proton-rich nuclei having $T_z$ = -2, namely $^{48}$Fe, $^{52}$Ni and $^{56}$Zn, produced in an experiment carried out at GANIL, are reported. In all the cases we have extracted the half-lives and the total $\\beta$-delayed proton emission branching ratios. We have measured the individual $\\beta$-delayed protons and $\\beta$-delayed $\\gamma$ rays with their branching ratios. Decay schemes have been determined for the three nuclei, and new energy levels are identified in the corresponding daughter nuclei. Competition between $\\beta$-delayed protons and gammas is observed in the de-excitation of the $T$ = 2 Isobaric Analogue States in all three cases. Absolute Fermi and Gamow-Teller transition strengths have been determined. The mass excesses of the nuclei under study have been deduced. In addition, we discuss in detail the data analysis taking as a test case $^{56}$Zn, where the exotic $\\beta$-delayed $\\gamma$-proton decay has been observed.

  1. Beta gets better with age

    OpenAIRE

    Tomunen, Tuomas

    2015-01-01

    The objective of my thesis is to study the cause for the low beta anomaly, which is an observation that the high beta stocks perform poorly relative to the low beta stocks. Based on earlier findings, I hypothesize that if a stock has high investor attention, its price overreacts to market-wide shocks, which results in a positive measurement error in its beta. Simultaneously, high attention causes overpricing, because the stock overreacts more often to positive shocks than to negat...

  2. Misleading Betas: An Educational Example

    Science.gov (United States)

    Chong, James; Halcoussis, Dennis; Phillips, G. Michael

    2012-01-01

    The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical "Anscombe quartet" results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the…

  3. Progress report on hot particle studies

    International Nuclear Information System (INIS)

    NCRP Report 106 on the effects of hot particles on the skin of pigs, monkeys, and humans was critically reviewed and reassessed. The analysis of the data of Forbes and Mikhail on the effects from activated UC2 particles, ranging in diameter from 144 μm to 328 μm, led to the formulation of a new model to predict both the threshold for acute ulceration and for ulcer diameter. In this model, a point dose of 27 Gy at a depth of 1.33 mm in tissue will cause an ulcer with a diameter determined by the radius to which this dose extends. Application of the model to the Forbes and Mikhail data obtained with mixed fission product beta particles yielded a ''threshold'' (5% probability) of 6 x 109 beta particles from a point source of high energy (2.25 MeV maximum) beta particles on skin. The above model was used to predict that approximately 1.2 x 1010 beta particles from Sr-Y-90 would produce similar effects, since few Sr-90 beta particles reach 1.33 mm depth. These emissions correspond to doses at 70-μm depth in tissue of approximately 5.3 to 5.5 Gy averaged over 1 cm2, respectively

  4. Systematic study of double beta decay to excited final states

    International Nuclear Information System (INIS)

    A systematic study of two-neutrino double beta (2νββ) decay to the final ground state and excited states is performed within a microscopic quasiparticle random phase approximation (QRPA) model. The excited states are assumed to have the structure of one or two QRPA phonons. This study of the 2νββ decay rates is complemented with the study of single-beta-decay feeding of the relevant nuclei taking part in the double beta process. The Woods-Saxon single-particle energies have been corrected near the Fermi surface by comparing the BCS quasi-particle energies with spectroscopic data of the relevant odd-mass nuclei. Pairing gaps, energy systematics of the Gamow-Teller-States and the available beta-decay data have been used to obtain effective, model-space adapted, two-body matrix elements starting from the G-matrix elements of the Bonn one-boson-exchange potential. This enables a parameter-free calculation of the double Gamow-Teller matrix elements and theoretical prediction of double-beta half lives. The harmonic two-phonon approximation has been used in the beta-decay analysis and the subsequent 2νββ calculations. (authors)

  5. Controlling Beam Halo-Chaos via Time-Delayed Feedback

    Institute of Scientific and Technical Information of China (English)

    FANG Jin-Qing; WENG Jia-Qiang; ZHU Lun-Wu; LUO Xiao-Shu

    2004-01-01

    The study of controlling high-current proton beam halo-chaos has become a key concerned issue for many important applications. In this paper, time-delayed feedback control method is proposed for beam halo-chaos. Particle in cell simulation results show that the method is very effective and has some advantages for high-current beam experiments and engineering.

  6. A Cold Flare with Delayed Heating

    Science.gov (United States)

    Fleishman, Gregory D.; Pal'shin, Valentin D.; Meshalkina, Natalia; Lysenko, Alexandra L.; Kashapova, Larisa K.; Altyntsev, Alexander T.

    2016-05-01

    Recently, a number of peculiar flares have been reported that demonstrate significant nonthermal particle signatures with low, if any, thermal emission, which implies a close association of the observed emission with the primary energy release/electron acceleration region. This paper presents a flare that appears “cold” at the impulsive phase, while displaying delayed heating later on. Using hard X-ray data from Konus-Wind, microwave observations by SSRT, RSTN, NoRH, and NoRP, context observations, and three-dimensional modeling, we study the energy release, particle acceleration, and transport, and the relationships between the nonthermal and thermal signatures. The flaring process is found to involve the interaction between a small loop and a big loop with the accelerated particles divided roughly equally between them. Precipitation of the electrons from the small loop produced only a weak thermal response because the loop volume was small, while the electrons trapped in the big loop lost most of their energy in the coronal part of the loop, which resulted in coronal plasma heating but no or only weak chromospheric evaporation, and thus unusually weak soft X-ray emission. The energy losses of the fast electrons in the big tenuous loop were slow, which resulted in the observed delay of the plasma heating. We determined that the impulsively accelerated electron population had a beamed angular distribution in the direction of the electric force along the magnetic field of the small loop. The accelerated particle transport in the big loop was primarily mediated by turbulent waves, which is similar to other reported cold flares.

  7. Reverse osmosis pilot plant experience in reprocessing plant for treatment of delay tank solutions

    International Nuclear Information System (INIS)

    Reverse osmosis (RO) technology will help in achieving ALARA concept, which will be beneficial for the environment. In present study, the removal of alpha activity, beta activity, nitrate and total dissolve salt (TDS) are investigated from delay tank solution utilizing RO pilot plant

  8. Synthesis of plastic scintillation microspheres: Alpha/beta discrimination

    International Nuclear Information System (INIS)

    Plastic scintillation microspheres (PSm) have been developed as an alternative for liquid scintillation cocktails due to their ability to avoid the mixed waste, besides other strengths in which the possibility for alpha/beta discrimination is included. The aim of this work was to evaluate the capability of PSm containing two combinations of fluorescence solutes (PPO/POPOP and pT/Bis-MSB) and variable amounts of a second organic solvent (naphthalene) to enhance the alpha/beta discrimination. Two commercial detectors with different Pulse Shape Discrimination performances (Quantulus and Triathler) were used to evaluate the alpha/beta discrimination. An optimal discrimination of alpha/beta particles was reached, with very low misclassification values (2% for beta particles and 0.5% for alpha particles), when PSm containing PPO/POPOP and between 0.6 and 2.0 g of naphthalene were evaluated using Triathler and the appropriate programme for data processing. - Highlights: • Plastic scintillation microspheres for α/β discrimination have been synthesised. • The energy transfer process in PSm with different compositions has been investigated. • The α/β discrimination capabilities of two commercial detectors have been evaluated. • 2% and 0.5% of misclassifications for β and α radionuclides have been achieved respectively

  9. Delayed unlatching mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Bzorgi, Fariborz M.

    2015-05-19

    In various embodiments an apparatus is presented for securing a structure such as a door, window, hatch, or gate that moves between an open and a closed position relative to a fixed structure to provide or deny access to a compartment, a room, an outdoor area, or a facility. Various embodiments provide a delay in opening the closure of sufficient duration to frustrate a rapid activation that might be desired by a person who is attempting to pass through the closure for some illicit purpose. Typically, hydraulics are used to activate the apparatus and no electrical energy or electronic signals are employed. In one embodiment, a plurality of actuations of a hand lever operates a hydraulic pump that moves a locking bolt from a first position in which a locking bolt is engaged with a recess in the fixed structure (preventing opening of a gate) to a second position in which the locking bolt is disengaged from the recess to permit opening of the gate.

  10. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne;

    2012-01-01

    We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... the period between 1999 and 2006. A history of radiation therapy was associated with increased risk of severe capsular contracture for 1- and 2-stage procedures, with adjusted hazard ratios (HR) of 3.3 (95% confidence interval [CI]: 0.9-12.4) and 7.2 (95% CI: 2.4-21.4), respectively. Similarly, a...... history of radiation therapy was associated with a non-significantly increased risk of reoperation after both 1-stage (HR = 1.4; 95% CI: 0.7-2.5) and 2-stage (HR = 1.6; 95% CI: 0.9-3.1) procedures. Reconstruction failure was highest (13.2%) in the 2-stage procedures with a history of radiation therapy...

  11. Delay Adjusted Incidence Infographic

    Science.gov (United States)

    This Infographic shows the National Cancer Institute SEER Incidence Trends. The graphs show the Average Annual Percent Change (AAPC) 2002-2011. For Men, Thyroid: 5.3*,Liver & IBD: 3.6*, Melanoma: 2.3*, Kidney: 2.0*, Myeloma: 1.9*, Pancreas: 1.2*, Leukemia: 0.9*, Oral Cavity: 0.5, Non-Hodgkin Lymphoma: 0.3*, Esophagus: -0.1, Brain & ONS: -0.2*, Bladder: -0.6*, All Sites: -1.1*, Stomach: -1.7*, Larynx: -1.9*, Prostate: -2.1*, Lung & Bronchus: -2.4*, and Colon & Rectum: -3/0*. For Women, Thyroid: 5.8*, Liver & IBD: 2.9*, Myeloma: 1.8*, Kidney: 1.6*, Melanoma: 1.5, Corpus & Uterus: 1.3*, Pancreas: 1.1*, Leukemia: 0.6*, Brain & ONS: 0, Non-Hodgkin Lymphoma: -0.1, All Sites: -0.1, Breast: -0.3, Stomach: -0.7*, Oral Cavity: -0.7*, Bladder: -0.9*, Ovary: -0.9*, Lung & Bronchus: -1.0*, Cervix: -2.4*, and Colon & Rectum: -2.7*. * AAPC is significantly different from zero (p<.05). Rates were adjusted for reporting delay in the registry. www.cancer.gov Source: Special section of the Annual Report to the Nation on the Status of Cancer, 1975-2011.

  12. Geometric time delay interferometry

    International Nuclear Information System (INIS)

    The space-based gravitational-wave observatory LISA, a NASA-ESA mission to be launched after 2012, will achieve its optimal sensitivity using time delay interferometry (TDI), a LISA-specific technique needed to cancel the otherwise overwhelming laser noise in the interspacecraft phase measurements. The TDI observables of the Michelson and Sagnac types have been interpreted physically as the virtual measurements of a synthesized interferometer. In this paper, I present Geometric TDI, a new and intuitive approach to extend this interpretation to all TDI observables. Unlike the standard algebraic formalism, Geometric TDI provides a combinatorial algorithm to explore exhaustively the space of second-generation TDI observables (i.e., those that cancel laser noise in LISA-like interferometers with time-dependent arm lengths). Using this algorithm, I survey the space of second-generation TDI observables of length (i.e., number of component phase measurements) up to 24, and I identify alternative, improved forms of the standard second-generation TDI observables. The alternative forms have improved high-frequency gravitational-wave sensitivity in realistic noise conditions (because they have fewer nulls in the gravitational-wave and noise response functions), and are less susceptible to instrumental gaps and glitches (because their component phase measurements span shorter time periods)

  13. Geometric Time Delay Interferometry

    CERN Document Server

    Vallisneri, M

    2005-01-01

    The space-based gravitational-wave observatory LISA, a NASA--ESA mission to be launched after 2012, will achieve its optimal sensitivity using Time Delay Interferometry (TDI), a LISA-specific technique needed to cancel the otherwise overwhelming laser noise in the inter-spacecraft phase measurements. In this paper I present_Geometric TDI_, a new, intuitive approach to derive the TDI observables and to understand them as the virtual measurements of a synthesized multi-beam interferometer. Unlike the standard algebraic formalism, Geometric TDI provides a combinatorial algorithm to explore exhaustively the space of _second-generation_ TDI observables (i.e., those that cancel laser noise in LISA-like interferometers with time-dependent armlengths). Using this algorithm, I survey the space of second-generation TDI observables of length (i.e., number of component phase measurements) up to 24, and I identify alternative, improved forms of the standard second-generation TDI observables. The alternative forms have imp...

  14. Magnetic bearing optical delay line

    NARCIS (Netherlands)

    Dool, T.C. van den; Kamphues, F.G.; Fouss, B.; Henrioulle, K.; Hogenhuis, H.

    2004-01-01

    TNO TPD, in close cooperation with Micromega-Dynamics and Dutch Space, has developed an advanced Optical Delay Line (ODL) for use in PRIMA, GENIE and other ground based interferometers. The delay line design is modular and flexible, which makes scaling for other applications a relatively easy task.

  15. Consumer Procrastination and Purchase Delay

    OpenAIRE

    Darpy, Denis

    2000-01-01

    Recent research on purchase delay have developed numerous situational and individual causes. This paper proposes Consumer Procrastination to conceptualize the individual factor which influence people to chronically delay their purchases. Consumer Procrastination is measured with a new scale. An experiment is designed to show the importance of its impact on the decision to not choose along with context effects.

  16. #FakeNobelDelayReasons

    CERN Multimedia

    2013-01-01

    Tuesday’s hour-long delay of the Nobel Prize in Physics announcement was (and still is) quite the cause for speculation. But on the Twittersphere, it was simply the catalyst for some fantastic puns, so-bad-they're-good physics jokes and other shenanigans. Here are some of our favourite #FakeNobelDelayReasons.    

  17. Delayed Reinforcement of Operant Behavior

    Science.gov (United States)

    Lattal, Kennon A.

    2010-01-01

    The experimental analysis of delay of reinforcement is considered from the perspective of three questions that seem basic not only to understanding delay of reinforcement but also, by implication, the contributions of temporal relations between events to operant behavior. The first question is whether effects of the temporal relation between…

  18. Complementarity of Neutrinoless Double Beta Decay and Cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Dodelson, Scott; Lykken, Joseph

    2014-03-20

    Neutrinoless double beta decay experiments constrain one combination of neutrino parameters, while cosmic surveys constrain another. This complementarity opens up an exciting range of possibilities. If neutrinos are Majorana particles, and the neutrino masses follow an inverted hierarchy, then the upcoming sets of both experiments will detect signals. The combined constraints will pin down not only the neutrino masses but also constrain one of the Majorana phases. If the hierarchy is normal, then a beta decay detection with the upcoming generation of experiments is unlikely, but cosmic surveys could constrain the sum of the masses to be relatively heavy, thereby producing a lower bound for the neutrinoless double beta decay rate, and therefore an argument for a next generation beta decay experiment. In this case as well, a combination of the phases will be constrained.

  19. Time-delay damping theory

    Institute of Scientific and Technical Information of China (English)

    洪峰

    2002-01-01

    In this paper, existing damping theories are briefly reviewed. On the basis of the existing damping theories, a new kind of damping theory, i.e., the time-delay damping theory, is developed. In the time-delay damping theory, the damping force is considered to be directly proportional to the increment of displacement. The response analysis of an SDOF time-delay damping system is carried out, and the methods for obtaining the solution for a time-delay damping system in the time domain as well as the frequency domain are given. The comparison between results from different damping theories shows that the time-delay damping theory is both reasonable and convenient.

  20. Timeline for Particle Collider in doubt

    CERN Multimedia

    Klapper, Bradley S

    2007-01-01

    "Officials at CERN said the possible delays in getting the particle collider back online are the result of the magnet failure and cooling processes that have been slower than expected for the 17-mile tunnel." (1,5 page)

  1. Beta-thalassemia

    Directory of Open Access Journals (Sweden)

    Origa Raffaella

    2010-05-01

    Full Text Available Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands, dilated myocardiopathy, liver fibrosis and cirrhosis. Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes, gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely

  2. Integration of BETA with Eclipse

    DEFF Research Database (Denmark)

    Andersen, Peter; Madsen, Ole Lehrmann; Enevoldsen, Mads Brøgger

    2004-01-01

    This paper presents language interoperability issues appearing in order to implement support for the BETA language in the Java-based Eclipse integrated development environment. One of the challenges is to implement plug-ins in BETA and be able to load them in Eclipse. In order to do this, some form...... of language interoperability between Java and BETA is required. The first approach is to use the Java Native Interface and use C to bridge between Java and BETA. This results in a workable, but complicated solution. The second approach is to let the BETA compiler generate Java class files. With this...... approach it is possible to implement plug-ins in BETA and even inherit from Java classes. In the paper the two approaches are described together with part of the mapping from BETA to Java class files. http://www.sciencedirect.com/science/journal/15710661...

  3. COM Support in BETA

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    1999-01-01

    Component technologies based on binary units of independent production are some of the most important contributions to software architecture and reuse during recent years. Especially the COM technologies and the CORBA standard from the Object Management Group have contributed new and interesting ...... principles for software architecture, and proven to be useful in parctice. In this paper ongoing work with component support in the BETA language is described....

  4. Beta decay for pedestrians

    CERN Document Server

    Lipkin, Harry Jeannot

    1962-01-01

    The ""pedestrian approach"" was developed to describe some essentially simple experimental results and their theoretical implications in plain language. In this graduate-level text, Harry J. Lipkin presents simply, but without oversimplification, the aspects of beta decay that can be understood without reference to the formal theory; that is, the reactions that follow directly from conservation laws and elementary quantum mechanics.The pedestrian treatment is neither a substitute for a complete treatment nor a watered-down version.

  5. Gauge Coupling Beta Functions in the Standard Model to Three Loops

    CERN Document Server

    Mihaila, Luminita N; Steinhauser, Matthias

    2012-01-01

    In this paper we compute the three-loop corrections to the beta functions of the three gauge couplings in the Standard Model of particle physics using the minimal subtraction scheme and taking into account Yukawa and Higgs self couplings.

  6. Delayed radiation neuropathy

    International Nuclear Information System (INIS)

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author)

  7. LHCb: $2\\beta_s$ measurement at LHCb

    CERN Multimedia

    Conti, G

    2009-01-01

    A measurement of $2\\beta_s$, the phase of the $B_s-\\bar{B_s}$ oscillation amplitude with respect to that of the ${\\rm b} \\rightarrow {\\rm c^{+}}{\\rm W^{-}}$ tree decay amplitude, is one of the key goals of the LHCb experiment with first data. In the Standard Model (SM), $2\\beta_s$ is predicted to be $0.0360^{+0.0020}_{-0.0016} \\rm rad$. The current constraints from the Tevatron are: $2\\beta_{s}\\in[0.32 ; 2.82]$ at 68$\\%$CL from the CDF experiment and $2\\beta_{s}=0.57^{+0.24}_{-0.30}$ from the D$\\oslash$ experiment. Although the statistical uncertainties are large, these results hint at the possible contribution of New Physics in the $B_s-\\bar{B_s}$ box diagram. After one year of data taking at LHCb at an average luminosity of $\\mathcal{L}\\sim2\\cdot10^{32}\\rm cm^{-2} \\rm s^{-1}$ (integrated luminosity $\\mathcal{L}_{\\rm int}\\sim 2 \\rm fb^{-1}$), the expected statistical uncertainty on the measurement is $\\sigma(2\\beta_s)\\simeq 0.03$. This uncertainty is similar to the $2\\beta_s$ value predicted by the SM.

  8. Measurement of the Syrian MNSR delayed neutron fraction and neutron generation time by noise analysis

    Energy Technology Data Exchange (ETDEWEB)

    Khamis, I. E-mail: ikhamis@aec.org.sy; Hainoun, A.; Suleiman, W

    2003-02-01

    Delayed neutron fraction {beta} and prompt neutron generation time {lambda} were determined for the Miniature Neutron Source Reactor of Syria using noise analysis technique. Small reactivity perturbations, step-wise and impulse in time, were introduced into the reactor at low power level i.e. zero-power. Power and reactivity versus time were obtained. Using the generalized least square algorithm and transfer function analysis, measurement of both the delayed neutron fraction and the neutron generation time were made. The MNSR values obtained for the prompt neutron generation time and delayed neutron fraction are 78.3{+-}1.3 {mu}s and 7.94{+-}0.11x10{sup -3} respectively. Both measured values of {beta} and {lambda} were found to be very consistent with previously measured and calculated ones reported in the Safety Analysis Report.

  9. Measurement of the Syrian MNSR delayed neutron fraction and neutron generation time by noise analysis

    International Nuclear Information System (INIS)

    Delayed neutron fraction beta and prompt neutron generation time LAMBDA were determined for the Miniature Neutron Source Reactor of Syria using noise analysis technique. Small reactivity perturbations, step-wise and impulse in time, were introduced into the reactor at low power level i.e. zero-power. Power and reactivity versus time were obtained. Using the generalized least square algorithm and transfer function analysis, measurement of both the delayed neutron fraction and the neutron generation time were made. The MNSR values obtained for the prompt neutron generation time and delayed neutron fraction are 78.3+-1.3 mu s and 7.94+-0.11x10 sup - sup 3 respectively. Both measured values of beta and LAMBDA were found to be very consistent with previously measured and calculated once reported in the Safety Analysis Report. (author)

  10. Split and delay photon correlation spectroscopy with a visible light

    Energy Technology Data Exchange (ETDEWEB)

    Rasch, Marten

    2016-04-15

    The development and performance of a setup constructed with the aim for the split pulse photon correlation spectroscopy is presented in this thesis. The double pulse time structure is accomplished with help of an Acusto-Optic Modulator (AOM) crystal, which mimics the splitting and delaying of photon pulses. The setup provides double pulses and allows to control the pulse width and delay and to synchronize them into one camera exposure window. The performance of the setup was successfully verified in a proof of principle experiment with a model system of polystyrene particles following Brownian motion. The measured radius of particles obtained with from the split pulse experiment (R{sub h}=(2.567±0.097) μm) is in agreement with the particle size provided by the manufacturer (R=(2.26±0.08) μm). The achieved results show higher statistics compared to a standard Dynamic Light Scattering (DLS) measurement.

  11. Split and delay photon correlation spectroscopy with a visible light

    International Nuclear Information System (INIS)

    The development and performance of a setup constructed with the aim for the split pulse photon correlation spectroscopy is presented in this thesis. The double pulse time structure is accomplished with help of an Acusto-Optic Modulator (AOM) crystal, which mimics the splitting and delaying of photon pulses. The setup provides double pulses and allows to control the pulse width and delay and to synchronize them into one camera exposure window. The performance of the setup was successfully verified in a proof of principle experiment with a model system of polystyrene particles following Brownian motion. The measured radius of particles obtained with from the split pulse experiment (Rh=(2.567±0.097) μm) is in agreement with the particle size provided by the manufacturer (R=(2.26±0.08) μm). The achieved results show higher statistics compared to a standard Dynamic Light Scattering (DLS) measurement.

  12. Development of multicomponent dosemeter for dosimetry of hot particles

    International Nuclear Information System (INIS)

    The multicomponent thermoluminescent beta dosimeter developed is described. Calibration was realised using beta and gamma emitters. Measurements of directional equivalent dose rate of beta radiation and effective beta energy were carried out in the working environment of a Nuclear Power Plant (Vandellos II) by means of thermoluminescent detectors. The effective beta energy ranges most frequently between 150 and 500 keV. The last version of the VARSKIN MOD 2 code has been used to calculate the directional dose equivalent rate H (0.07,0) and the personal dose equivalent rate Hp (10) corresponding to the hot particles found. A comparison between the calculated and the experimental values is presented. (Author)

  13. NEUTRINOLESS DOUBLE BETA DECAY: AN EXTREME CHALLENGE

    Directory of Open Access Journals (Sweden)

    Fernando Ferroni

    2013-12-01

    Full Text Available Neutrino-less Double Beta Decay is the only known way to possibly resolve the nature of neutrino mass. The chances to cover the mass region predicted by the inverted hierarchy require a step forward in detector capability. A possibility is to make use of scintillating bolometers. These devices shall have a great power in distinguishing signals from alfa particles from those induced by electrons. This feature might lead to an almost background-free experiment. Here the Lucifer concept will be introduced and the prospects related to this project will be discussed.

  14. Attosecond delays in molecular photoionization

    CERN Document Server

    Huppert, Martin; Baykusheva, Denitsa; von Conta, Aaron; Wörner, Hans Jakob

    2016-01-01

    We report measurements of energy-dependent attosecond photoionization delays between the two outer-most valence shells of N$_2$O and H$_2$O. The combination of single-shot signal referencing with the use of different metal foils to filter the attosecond pulse train enables us to extract delays from congested spectra. Remarkably large delays up to 160 as are observed in N$_2$O, whereas the delays in H$_2$O are all smaller than 50 as in the photon-energy range of 20-40 eV. These results are interpreted by developing a theory of molecular photoionization delays. The long delays measured in N$_2$O are shown to reflect the population of molecular shape resonances that trap the photoelectron for a duration of up to $\\sim$110 as. The unstructured continua of H$_2$O result in much smaller delays at the same photon energies. Our experimental and theoretical methods make the study of molecular attosecond photoionization dynamics accessible.

  15. Review of experimental methods for evaluating effective delayed neutron fraction

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, Yoshihiro [Nagoya Univ. (Japan). School of Engineering

    1997-03-01

    The International Effective Delayed Neutron Fraction ({beta}{sub eff}) Benchmark Experiments have been carried out at the Fast Critical Assembly of Japan Atomic Energy Research Institute since 1995. Researchers from six countries, namely France, Italy, Russia, U.S.A., Korea, and Japan, participate in this FCA project. Each team makes use of each experimental method, such as Frequency Method, Rossi-{alpha} Method, Nelson Number Method, Cf Neutron Source Method, and Covariance Method. In this report these experimental methods are reviewed. (author)

  16. Bound beta-decay: BOB

    International Nuclear Information System (INIS)

    For many years exotic decay modes of the neutron have been investigated as possible doorways to the exploration of new physics. The bound beta-decay (BOB) of the neutron into a hydrogen atom and an anti-neutrino offers a very elegant method to study neutrino helicities. However, this rare decay has not yet been observed for the free neutron, owing to the challenge of measuring a decay involving only electrically neutral particles and with an estimated branching ratio of only a few 106 of the three-body decay mode. During the past few years scientists from the TUM E18 Group have developed a novel experimental scheme which addresses all necessary problems associated with the observation of this two-body neutron decay in a very coherent way. The BOB experiment shall be installed at a tangential beam tube of a powerful research reactor such as the SR6 at the FRMII in Garching or H6-H7 beam tube at ILL. This talk will provide insights and ideas on how such an experiment is to be performed.

  17. Spectroscopy of β--delayed nγ-coincidences

    International Nuclear Information System (INIS)

    As has originally been demonstrated by γ-ray measurements, beta-delayed neutron emission from precursors with large energy windows (Qsub(β)-Bsub(n)) can not only lead to the ground state but also to excited states of the final nucleus. In these cases the construction of β-strength functions (Ssub(β)-) requires unfolding of the neutron singles spectra. The optimum spectroscopic method therefore is the measurement of delayed neutrons in coincidence with γ-rays depopulating those excited final states. With a new set-up high-resolution n%GA-coincidence spectra were measured for 94-96Rb (β-nγ) decay. (orig./AH)

  18. Time Delay in Molecular Photoionization

    CERN Document Server

    Hockett, P; Villeneuve, D M; Corkum, P B

    2015-01-01

    Time-delays in the photoionization of molecules are investigated. As compared to atomic ionization, the time-delays expected from molecular ionization present a much richer phenomenon, with a strong spatial dependence due to the anisotropic nature of the molecular scattering potential. We investigate this from a scattering theory perspective, and make use of molecular photoionization calculations to examine this effect in representative homonuclear and hetronuclear diatomic molecules, nitrogen and carbon monoxide. We present energy and angle-resolved maps of the Wigner delay time for single-photon valence ionization, and discuss the possibilities for experimental measurements.

  19. A low-noise beta-radiometer

    International Nuclear Information System (INIS)

    The two-channel detector for a low-noise (down to 0.06 sec-1) beta-radiometer for measuring the mass concentration of 90Sr in the environment after the chemical extraction of strontium by the oxalate-nitrate method was certified at the D.I. Mendeleev Institute of Metrology (certificate No. 137/93). A detector unit using two end-window self-quenching counters with thin input windows (8 μm thick and 60 mm in diameter) operating as a Geiger-Mueller counter and filled with a mixture of 90% helium (atomic gas) and 10% ethanol (organic molecules) can measure the beta-activity of two substrates concurrently. It is often used to detect the beta-radiation of 90Sr. This isotope produces particles with energies ranging from 180 to 1000 keV, and the detection efficiency is 50% at a level of 0.1 Bq after measuring for 20 min with an uncertainty of 25%

  20. A background free double beta decay experiment

    CERN Document Server

    Giomataris, Ioannis

    2010-01-01

    We present a new detection scheme for rejecting backgrounds in neutrino less double beta decay experiments. It relies on the detection of Cherenkov light emitted by electrons in the MeV region. The momentum threshold is tuned to reach a good discrimination between background and good events. We consider many detector concepts and a range of target materials. The most promising is a high-pressure 136Xe emitter for which the required energy threshold is easily adjusted. Combination of this concept and a high pressure Time Projection Chamber could provide an optimal solution. A simple and low cost effective solution is to use the Spherical Proportional Counter that provides two delayed signals from ionization and Cherenkov light. In solid-state double beta decay emitters, because of their higher density, the considered process is out of energy range. An alternative solution could be the development of double decay emitters with lower density by using for instance the aerogel technique. It is surprising that a te...

  1. Delay-induced instabilities in self-propelling swarms

    OpenAIRE

    Forgoston, Eric; Schwartz, Ira B.

    2008-01-01

    We consider a general model of self-propelling particles interacting through a pairwise attractive force in the presence of noise and communication time delay. Previous work by Erdmann, et al. [Phys. Rev. E {\\bf 71}, 051904 (2205)] has shown that a large enough noise intensity will cause a translating swarm of individuals to transition to a rotating swarm with a stationary center of mass. We show that with the addition of a time delay, the model possesses a transition that depends on the size...

  2. Delays and networked control systems

    CERN Document Server

    Hetel, Laurentiu; Daafouz, Jamal; Johansson, Karl

    2016-01-01

    This edited monograph includes state-of-the-art contributions on continuous time dynamical networks with delays. The book is divided into four parts. The first part presents tools and methods for the analysis of time-delay systems with a particular attention on control problems of large scale or infinite-dimensional systems with delays. The second part of the book is dedicated to the use of time-delay models for the analysis and design of Networked Control Systems. The third part of the book focuses on the analysis and design of systems with asynchronous sampling intervals which occur in Networked Control Systems. The last part of the book exposes several contributions dealing with the design of cooperative control and observation laws for networked control systems. The target audience primarily comprises researchers and experts in the field of control theory, but the book may also be beneficial for graduate students. .

  3. Language Delays in Toddlers: Information for Parents

    Science.gov (United States)

    ... Stages Listen Español Text Size Email Print Share Language Delays in Toddlers: Information for Parents Page Content ... situation or repeats scripts from TV Delays in language Delays in language are the most common types ...

  4. Nano-coating of beta-galactosidase onto the surface of lactose by using an ultrasound-assisted technique

    DEFF Research Database (Denmark)

    Genina, Natalja; Räikkönen, Heikki; Heinämäki, Jyrki;

    2010-01-01

    We nano-coated powdered lactose particles with the enzyme beta-galactosidase using an ultrasound-assisted technique. Atomization of the enzyme solution did not change its activity. The amount of surface-attached beta-galactosidase was measured through its enzymatic reaction product D-galactose us......We nano-coated powdered lactose particles with the enzyme beta-galactosidase using an ultrasound-assisted technique. Atomization of the enzyme solution did not change its activity. The amount of surface-attached beta-galactosidase was measured through its enzymatic reaction product D...

  5. Xeroradiography in. beta. -thalassaemia

    Energy Technology Data Exchange (ETDEWEB)

    Scutellari, P.N.; Orzincolo, C.; Tamarozzi, R.

    1985-01-01

    Xeroradiographic investigations of the skull, hand, and elbow were performed on 27 patients with homozygous ..beta..-thalassaemia. The results were compared with plain radiographic examinations. Xeroradiography, because of its technical properties (i.e. edge contrast enhancement and wide latitude), was shown to demonstrate cortical thinning of long bones, swelling of the diploic space in the skull, and reticulated patterns in the elbow better than standard radiography. Moreover, the use of 'positive' mode imaging was shown to have advantages in the study of the skull and extremities.

  6. Realized Beta GARCH

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Voev, Valeri Radkov

    2014-01-01

    particularly useful for modeling financial returns during periods of rapid changes in the underlying covariance structure. When applied to market returns in conjunction with returns on an individual asset, the model yields a dynamic model specification of the conditional regression coefficient that is known as...... conditional beta series during the financial crises.......We introduce a multivariate generalized autoregressive conditional heteroskedasticity (GARCH) model that incorporates realized measures of variances and covariances. Realized measures extract information about the current levels of volatilities and correlations from high-frequency data, which is...

  7. Tunable silicon CROW delay lines

    Science.gov (United States)

    Morichetti, Francesco; Canciamilla, Antonio; Torregiani, Matteo; Ferrari, Carlo; Melloni, Andrea; Martinelli, Mario

    2010-05-01

    Tunable coupled resonator optical waveguides (CROWs) are powerful and versatile devices that can be used to dynamically control the delay of optical data streams on chip. In this contribution we show that CROW delay lines fabricated on a silicon on insulator (SOI) platform are suitable for applications in the emerging scenario of optical systems at 100 Gbit/s. Issues concerning technology, design, limits and applications of SOI CROWs are discussed. The performances of silicon CROW delay lines activated by thermal tuning are compared to those of glass CROW in terms of power consumption, thermal crosstalk and reconfiguration speed. The continuous delay of 10-ps long optical pulses by 8 bit length is demonstrated by using a silicon CROW with a bandwidth of 87 GHz and made of 12 RRs. At 100 Gbit/s this structure provides comparable figures of merit (fractional delay of 0.75 bit/RR and fractional loss of 0.7 dB per bit-delay) of state-of-the art glass CROW operating at 10 Gbit/s, yet the area of the latter being three order of magnitude larger. The compatibility of silicon CROW with the emerging 100 Gbit/s systems is demonstrated by showing error-free phase-preserving propagation of a 100 Gbit/s return-to-zero (RZ) polarization-division-multiplexing (PolDM) differential quaternary phase shit keying (DQPSK) signal dynamically delayed by the CROW. It is also demonstrated that a silicon CROW can be used in a PolDM system to introduce a polarization selective delay in order to optimize the time interleaving of the two orthogonally polarized data streams.

  8. Deconstructing delayed posttraumatic stress disorder

    OpenAIRE

    Smid, G.E.

    2011-01-01

    According to the Diagnostic and Statistical Manual of Mental Disorders, delayed posttraumatic stress disorder (PTSD) must be diagnosed in individuals fulfilling criteria for PTSD if the onset of symptoms is at least six months after the trauma. The purpose of this thesis was to establish the prevalence of delayed PTSD and to examine factors that may explain its occurrence. We conducted a meta-analysis and examined prospective data from disaster survivors, unaccompanied refugee minors, and arm...

  9. Systematics in delayed neutron yields

    Energy Technology Data Exchange (ETDEWEB)

    Ohsawa, Takaaki [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.

    1998-03-01

    An attempt was made to reproduce the systematic trend observed in the delayed neutron yields for actinides on the basis of the five-Gaussian representation of the fission yield together with available data sets for delayed neutron emission probability. It was found that systematic decrease in DNY for heavier actinides is mainly due to decrease of fission yields of precursors in the lighter side of the light fragment region. (author)

  10. Basin stability in delayed dynamics

    Science.gov (United States)

    Leng, Siyang; Lin, Wei; Kurths, Jürgen

    2016-02-01

    Basin stability (BS) is a universal concept for complex systems studies, which focuses on the volume of the basin of attraction instead of the traditional linearization-based approach. It has a lot of applications in real-world systems especially in dynamical systems with a phenomenon of multi-stability, which is even more ubiquitous in delayed dynamics such as the firing neurons, the climatological processes, and the power grids. Due to the infinite dimensional property of the space for the initial values, how to properly define the basin’s volume for delayed dynamics remains a fundamental problem. We propose here a technique which projects the infinite dimensional initial state space to a finite-dimensional Euclidean space by expanding the initial function along with different orthogonal or nonorthogonal basis. A generalized concept of basin’s volume in delayed dynamics and a highly practicable calculating algorithm with a cross-validation procedure are provided to numerically estimate the basin of attraction in delayed dynamics. We show potential applicabilities of this approach by applying it to study several representative systems of biological or/and physical significance, including the delayed Hopfield neuronal model with multistability and delayed complex networks with synchronization dynamics.

  11. Design and operation of dust measuring instrumentation based on the beta-radiation method

    International Nuclear Information System (INIS)

    The theory, instrument design aspects and applications of beta-radiation attenuation for the measurement of mass concentration of airborne particulates are reviewed. Applicable methods of particle collection, beta sensing configurations, source and detector design criteria, and electronic signal processing are treated. Advantages, limitations, and error sources of beta-attenuation instrumentation are analysed. Applications to industrial dust measurements, source testing, ambient monitoring, and particle size analysis are the major areas of practical utilization of this technique, and its inherent capability for automated and unattended operation provides compatibility with process control surveillance and alarm, telemetry, and incorporation into pollution monitoring network sensing stations. (orig.)

  12. The relevance of dose for low-energy beta emitters

    International Nuclear Information System (INIS)

    Specific issues in risk assessment for low-energy beta emitters include specification of the radiation weighting factor, values of relative biological effectiveness for specific or accurate risk estimates, non-uniformities of dose within tissues and cells, and use of standard tissue weighting factors for non-uniform situations. Unusual features of low-energy beta emitters include: increased average ionisation density on subcellular (and cellular) scales; short ranges of the beta electrons; non-uniformity of the absorbed dose over subcellular, cellular, and tissue dimensions; reduced hit frequencies; nuclear transmutations; different chemical forms, influencing biokinetics and dose distributions; and large isotopic mass differences, particularly in the case of tritium and hydrogen. Many of these features are not included explicitly in conventional radiation protection dosimetry, although they may be partly included in experimental determinations of relative biological effectiveness. Theoretical and experimental studies have shown low-energy electrons to be particularly efficient in producing double-strand breaks in DNA, including complex double-strand breaks. Hence, on fundamental grounds, tritium beta particles should be expected to have greater biological effectiveness per unit absorbed dose than 60Co gamma-rays or orthovoltage x-rays. For practical purposes, and in view of the paucity of epidemiological estimates of risk from low-energy electrons, consideration should be given to applying a raised relative biological effectiveness, say of value 2, to all low-energy internal emitters, including beta particles and soft x-ray emissions.

  13. Microscopic study of muon-capture transitions in nuclei involved in double-beta-decay processes

    CERN Document Server

    Kortelainen, M

    2003-01-01

    Total and partial ordinary muon-capture (OMC) rates to 1 sup + and 2 sup - states are calculated in the framework of the proton-neutron quasiparticle random-phase approximation (pnQRPA) for several nuclei involved in double-beta-decay processes. The aim is to obtain information on intermediate states involved in double-beta-decay transitions having these nuclei as either daughter or parent nuclei. It is found that the OMC observables, just like the 2 nu beta beta-decay amplitudes, strongly depend on the particle-particle part of the proton-neutron interaction. First experiments measuring the partial OMC rates for nuclei involved in double beta decays have recently been performed.

  14. Double beta decay: present status

    OpenAIRE

    Barabash, A. S.

    2008-01-01

    The present status of double beta decay experiments (including the search for $2\\beta^{+}$, EC$\\beta^{+}$ and ECEC processes) are reviewed. The results of the most sensitive experiments are discussed. Average and recommended half-life values for two-neutrino double beta decay are presented. Conservative upper limits on effective Majorana neutrino mass and the coupling constant of the Majoron to the neutrino are established as $ < 0.75$ eV and $ < 1.9 \\cdot 10^{-4}$, respectively. Proposals fo...

  15. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  16. A Cold Flare With Delayed Heating

    CERN Document Server

    Fleishman, Gregory D; Meshalkina, Natalia; Lysenko, Alexandra L; Kashapova, Larisa K; Altyntsev, Alexander T

    2016-01-01

    Recently, a number of peculiar flares have been reported, which demonstrate significant non-thermal particle signatures with a low, if any, thermal emission, that implies close association of the observed emission with the primary energy release/electron acceleration region. This paper presents a flare that appears a "cold" one at the impulsive phase, while displaying a delayed heating later on. Using HXR data from \\kw, microwave observations by SSRT, RSTN, NoRH and NoRP, context observations, and 3D modeling, we study the energy release, particle acceleration and transport, and the relationships between the nonthermal and thermal signatures. The flaring process is found to involve interaction between a small and a big loop and the accelerated particles divided in roughly equal numbers between them. Precipitation of the electrons from the small loop produced only weak thermal response because the loop volume was small, while the electrons trapped in the big loop lost most of their energy in the coronal part o...

  17. Radiolytical oxidation of gaseous iodine by beta radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kaerkelae, Teemu; Auvinen, Ari; Kekki, Tommi; Kotiluoto, Petri; Lyyraenen, Jussi [VTT Technical Research Centre of Finland, Espoo (Finland); Jokiniemi, Jorma [VTT Technical Research Centre of Finland, Espoo (Finland); Eastern Finland Univ., Kuopio (Finland)

    2015-07-01

    Iodine is one of the most radiotoxic fission product released from fuel during a severe nuclear power plant accident. Within the containment building, iodine compounds can react e.g. on the painted surfaces and form gaseous organic iodides. In this study, it was found out that gaseous methyl iodide (CH{sub 3}I) is oxidised when exposed to beta radiation in an oxygen containing atmosphere. As a result, nucleation of aerosol particles takes place and the formation of iodine oxide particles is suggested. These particles are highly hygroscopic. They take up water from the air humidity and iodine oxides dissolve within the droplets. In order to mitigate the possible source term, it is of interest to understand the effect of beta radiation on the speciation of iodine.

  18. Expert (exotic Particle Emission and Radioactivity by Tracking) Studies at the Super-Frs Spectrometer

    Science.gov (United States)

    Geissel, H.; Kiselev, O.; Mukha, I.; Simon, H.; Scheidenberger, C.; Weick, H.; Winkler, M.; Fomichev, A.; Belogurov, S.; Bezbakh, A.; Chudoba, V.; Golovkov, M.; Gorshkov, A.; Itkis, Y.; Kaminski, G.; Knyazev, A.; Knyazheva, G.; Kozulin, E.; Krupko, S.; Mianowski, S.; Rymzhanova, S.; Sidorchuk, S.; Sharov, P.; Slepnev, R.; Ter-Akopian, G.; Zagrebaev, V.; Pfützner, M.; Dominik, W.; Janas, Z.; Mazzocchi, Ch.; Mianowski, S.; Korsheninnikov, A. A.; Kuzmin, E. A.; Nikolskii, E. Yu.; Eremin, I.; Eremin, V.; Fadeeva, N.; Terukov, E.; Tuboltsev, Yu.; Verbitskaya, E.; Ershov, S. N.; Egorova, I. A.; Nasirov, A. K.; Dunin, V. B.; Alkhazov, G. D.; Dobrovolsky, A. V.; Khanzadeev, A. V.; Parfenova, Yu. L.; Xu, X.; Kaminski, G.; Kopatch, Y.

    2015-06-01

    The proposal EXPERT is suggested for the Super-FRS Collaboration physics program [1] in the NUSTAR Collaboration of the project FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. It is aimed at studies of the nuclear landscape beyond the proton and neutron drip-lines and intends to push researches up to limits of nuclear existence. By combining the EXPERT instrumentation (two tracking techniques applied for radioactivity and nuclear decays in-flight), the phenomena of multi-nucleon radioactivity, resonance decays in continuum, beta-delayed exotic decays and exotic excitation modes can be studied via observations of particle emissions, including the 2p, 4p, 6p, n, 2n, 4n, 6n channels.

  19. Scintillator based beta batteries

    Science.gov (United States)

    Rensing, Noa M.; Tiernan, Timothy C.; Shirwadkar, Urmila; O'Dougherty, Patrick; Freed, Sara; Hawrami, Rastgo; Squillante, Michael R.

    2013-05-01

    Some long-term, remote applications do not have access to conventional harvestable energy in the form of solar radiation (or other ambient light), wind, environmental vibration, or wave motion. Radiation Monitoring Devices, Inc. (RMD) is carrying out research to address the most challenging applications that need power for many months or years and which have undependable or no access to environmental energy. Radioisotopes are an attractive candidate for this energy source, as they can offer a very high energy density combined with a long lifetime. Both large scale nuclear power plants and radiothermal generators are based on converting nuclear energy to heat, but do not scale well to small sizes. Furthermore, thermo-mechanical power plants depend on moving parts, and RTG's suffer from low efficiency. To address the need for compact nuclear power devices, RMD is developing a novel beta battery, in which the beta emissions from a radioisotope are converted to visible light in a scintillator and then the visible light is converted to electrical power in a photodiode. By incorporating 90Sr into the scintillator SrI2 and coupling the material to a wavelength-matched solar cell, we will create a scalable, compact power source capable of supplying milliwatts to several watts of power over a period of up to 30 years. We will present the latest results of radiation damage studies and materials processing development efforts, and discuss how these factors interact to set the operating life and energy density of the device.

  20. Flavour of fundamental particles and prime numbers

    International Nuclear Information System (INIS)

    The discreteness and continuity as described by the ratio of the discreteness of the n's and the continuous spread of n/2n, which is directly connected with the width and lifetimes of fundamental particles, the flavours of fundamental particles can be directly obtained. The behaviour of beta decay and the energy levels of light nuclei can also be predicted. The appearance of primes also seems to suggest that further application of reductionism to fundamental particles is not possible

  1. Testing the importance of collective correlations in neutrinoless $\\beta\\beta$ decay

    CERN Document Server

    Menéndez, J; Engel, J; Martínez-Pinedo, G; Rodríguez, T R

    2016-01-01

    We investigate the extent to which theories of collective motion can capture the physics that determines the nuclear matrix elements governing neutrinoless double-beta decay. To that end we calculate the matrix elements for a series of isotopes in the full $pf$ shell, omitting no spin-orbit partners. With the inclusion of isoscalar pairing, a separable collective Hamiltonian that is derived from the shell model effective interaction reproduces the full shell-model matrix elements with good accuracy. A version of the generator coordinate method that includes the isoscalar pairing amplitude as a coordinate also reproduces the shell model results well, an encouraging result for theories of collective motion, which can include more single-particle orbitals than the shell model. We briefly examine heavier nuclei relevant for experimental double-beta decay searches, in which shell-model calculations with all spin-orbit partners are not feasible; our estimates suggest that isoscalar pairing also plays a significant ...

  2. Lepton number violating new physics and neutrinoless double beta decay

    International Nuclear Information System (INIS)

    Neutrinoless double beta decay is a very sensitive experimental probe for lepton number violating (ΔL=2) physics beyond the Standard Model. Whatever the new physics mechanism is that triggers the decay, according to the well known Schechter-Valle (or Black Box) theorem, it will induce a Majorana mass term for neutrinos. Neutrinoless double beta decay is therefore the only known possibility to ascertain in the foreseeable future whether the neutrino is a Dirac or a Majorana particle. We discuss the relation between various lepton number violating operators, Majorana neutrino masses, and future experiments.

  3. Power output and efficiency of beta-emitting microspheres

    OpenAIRE

    Cheneler, David; Ward, Michael C L

    2015-01-01

    Current standard methods to calculate the dose of radiation emitted during medical applications by beta-minus emitting microspheres rely on an over-simplistic formalism. This formalism is a function of the average activity of the radioisotope used and the physiological dimensions of the patient only. It neglects the variation in energy of the emitted beta particle due to self-attenuation, or self-absorption, effects related to the finite size of the sphere. Here it is assumed the sphere is co...

  4. Status and prospects of searches for neutrinoless double beta decay

    CERN Document Server

    Schwingenheuer, Bernhard

    2012-01-01

    The simultaneous beta decay of two neutrons in a nucleus without the emission of neutrinos (called neutrinoless double beta decay) is a lepton number violating process which is not allowed in the Standard Model of particle physics. More than a dozen experiments using different candidate isotopes and a variety of detection techniques are searching for this decay. Some (EXO-200, Kamland-Zen, GERDA) started to take data recently. EXO and Kamland-Zen have reported first limits of the half life $T_{1/2}^{0\

  5. Using natural beta emission for detecting concealed tobacco in parcels

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Jeremy [Laboratory for Threat Material Detection, Department of Mechanical Engineering, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3 (Canada); Hussein, Esam M.A. [Laboratory for Threat Material Detection, Department of Mechanical Engineering, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3 (Canada)], E-mail: hussein@unb.ca

    2007-10-15

    It is suspected that postal systems are used for the illegal shipment of tobacco products to circumvent taxation and excise payments. This paper demonstrates that beta-particle emission from the potassium-40 contained in tobacco can be used to passively detect its presence in paperboard postal parcels. The same concept can be utilized for the detection of marijuana, whose leaves are also rich in {sup 40}K. The combination of high beta activity and a low weight is a good indicator of the presence of these two contraband materials.

  6. Using natural beta emission for detecting concealed tobacco in parcels

    International Nuclear Information System (INIS)

    It is suspected that postal systems are used for the illegal shipment of tobacco products to circumvent taxation and excise payments. This paper demonstrates that beta-particle emission from the potassium-40 contained in tobacco can be used to passively detect its presence in paperboard postal parcels. The same concept can be utilized for the detection of marijuana, whose leaves are also rich in 40K. The combination of high beta activity and a low weight is a good indicator of the presence of these two contraband materials

  7. Delay Independent Criterion for Multiple Time-delay Systems

    Science.gov (United States)

    Chang, C. J.; Liu, K. F. R.; Yeh, K.; Chen, C. W.; Chung, P. Y.

    Based on the fuzzy Lyapunov method, this work addresses the stability conditions for nonlinear systems with multiple time delays to ensure the stability of building structure control systems. The delay independent conditions are derived via the traditional Lyapunov and fuzzy Lyapunov methods for multiple time-delay systems as approximated by the Tagagi-Sugeno (T-S) fuzzy model. The fuzzy Lyapunov function is defined as a fuzzy blending of quadratic Lyapunov functions. A parallel distributed compensation (PDC) scheme is utilized to construct a global fuzzy logic control (FLC) by blending all linear local state feedback controllers in the controller design procedure. Furthermore, the H infinity performance and robustness of the design for modeling errors also need to be considered in the stability conditions.

  8. Beet necrotic yellow vein virus accumulates inside resting spores and zoosporangia of its vector Polymyxa betae BNYVV infects P. betae

    Directory of Open Access Journals (Sweden)

    Payton Mark

    2007-04-01

    Full Text Available Abstract Background Plasmodiophorids and chytrids are zoosporic parasites of algae and land plant and are distributed worldwide. There are 35 species belonging to the order Plasmodiophorales and three species, Polymyxa betae, P. graminis, and Spongospora subterranea, are plant viral vectors. Plasmodiophorid transmitted viruses are positive strand RNA viruses belonging to five genera. Beet necrotic yellow vein virus (BNYVV and its vector, P. betae, are the causal agents for rhizomania. Results Evidence of BNYVV replication and movement proteins associating with P. betae resting spores was initially obtained using immunofluorescence labeling and well characterized antisera to each of the BNYVV proteins. Root cross sections were further examined using immunogold labeling and electron microscopy. BNYVV proteins translated from each of the four genomic and subgenomic RNAs accumulate inside P. betae resting spores and zoospores. Statistical analysis was used to determine if immunolabelling detected viral proteins in specific subcellular domains and at a level greater than in control samples. Conclusion Virus-like particles were detected in zoosporangia. Association of BNYVV replication and movement proteins with sporangial and sporogenic stages of P. betae suggest that BNYVV resides inside its vector during more than one life cycle stage. These data suggest that P. betae might be a host as well as a vector for BNYVV

  9. Development of an effective delayed neutron fraction calculation code for hexagonal core

    International Nuclear Information System (INIS)

    BETA-K, an effective delayed neutron fraction calculation code consistent with Nodal Expansion Method(NEM) of hexagonal geometric core, has been developed. By using relevant output files of DIF3D code, it can calculate the effective delayed neutron fraction(betaeff) and neutron lifetime(leff) for each fissionable isotope, composition of fuels and over the whole core. BETA-K code has been validated by comparing the calculated values to the measured ones of effective delayed neutron fraction in two critical experiments, BFS73-1 and BFS55-1. BFS73-1 is a metal uranium core and BFS55-1 is a metal plutonium core. The C/E values, 1.007 and 0.992 for BFS73-1 and BFS55-1 respectively, agreed well with the experimental values within the experiment errors. BETA-K code predicts 0.00709 and 0.356μ sec as the effective delayed neutron fraction and neutron life time for the uranium metallic fueled equilibrium core of 150MWe KALIMER

  10. The Technology and Applications of Large Fission Product Beta Sources

    International Nuclear Information System (INIS)

    Beta emitters have not received consideration as large sources of radiation power because in the past, the radiation processes of interest have been based on particles with high penetration power; hence the great emphasis on gammas and artificially accelerated electrons. About four years ago, it became apparent that a broad field of potential applications involving surface radiation treatment was developing, e. g. surface modification of formed plastics by graft copolymerization and surface pasteurization of food. For these applications, penetration in depth is wasteful and potentially harmful. Also there are two other areas for which machine electrons were not well suited: radiation-induced chemical syntheses in pressure vessels, and certain types of free radical chain reactions for which the production rate per kilowatt decreases with the square root of the dose rate. Broad area beta sources showed obvious potential advantages in all these categories and, since they are available in good yield from the fission process, merited a careful re-appraisal. On the basics of these considerations an AEC sponsored study of the applications and technology of fission product beta sources was performed. The results indicate the following: 1. There are promising areas for commercial application of fission product beta emitters in the radiation processing field, particularly in the graft copolymerization modification of formed plastic surfaces and textiles. 2. Massive, rugged, inert, safe, inexpensive beta sources may be fabricated by suitable extensions of existing techniques. Source-bearing glass formulations show particular promise. 3. Beta absorption calculations indicate that extended sources can be designed with power utilization efficiencies as high as 20 per cent. Equations and curves describing dosage and beta utilization efficiency as a function of the geometry and composition of various source-target systems were developed. An experimental program is in progress to

  11. Delay-induced instabilities in self-propelling swarms

    Science.gov (United States)

    Forgoston, Eric; Schwartz, Ira B.

    2008-03-01

    We consider a general model of self-propelling particles interacting through a pairwise attractive force in the presence of noise and communication time delay. Previous work by Erdmann [Phys. Rev. E 71, 051904 (2005)] has shown that a large enough noise intensity will cause a translating swarm of individuals to transition to a rotating swarm with a stationary center of mass. We show that with the addition of a time delay, the model possesses a transition that depends on the size of the coupling amplitude. This transition is independent of the initial swarm state (traveling or rotating) and is characterized by the alignment of all of the individuals along with a swarm oscillation. By considering the mean field equations without noise, we show that the time-delay-induced transition is associated with a Hopf bifurcation. The analytical result yields good agreement with numerical computations of the value of the coupling parameter at the Hopf point.

  12. BETA SPECTRA. I. Negatrons spectra

    International Nuclear Information System (INIS)

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  13. The best-beta CAPM

    NARCIS (Netherlands)

    L. Zou

    2006-01-01

    The issue of 'best-beta' arises as soon as potential errors in the Sharpe-Lintner-Black capital asset pricing model (CAPM) are acknowledged. By incorporating a target variable into the investor preferences, this study derives a best-beta CAPM (BCAPM) that maintains the CAPM's theoretical appeal and

  14. RAVEN Beta Release

    Energy Technology Data Exchange (ETDEWEB)

    Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, Andrea [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cogliati, Joshua Joseph [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kinoshita, Robert Arthur [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Congjian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Maljovec, Daniel Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Talbot, Paul William [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  15. RAVEN Beta Release

    International Nuclear Information System (INIS)

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  16. Beta Beams Implementation at CERN

    CERN Document Server

    Hansen, Christian

    2011-01-01

    Beta Beam,the concept of generating a pure and intense (anti) neutrino beam by letting accelerated radioactive ions beta decay in a storage ring, called Decay Ring (DR), is the base of one of the proposed next generation neutrino oscillation facilities, necessary for a complete study of the neutrino oscillation parameter space. Sensitivities of the unknown neutrino oscillation parameters depend on the Decay Ring's ion intensity and of it's duty factor (the filled ratio of the ring). Therefore efficient ion production, stripping, bunching, acceleration and storing are crucial sub-projects under study and development within the Beta Beam collaboration. Specifically the feasibility of these tasks as parts of a Beta Beam implementation at CERN will be discussed in this report. The positive impact of the large {\\theta}13 indications from T2K on the Beta Beam performance will also be discussed.

  17. 49 CFR 236.563 - Delay time.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time....

  18. On Stability of Linear Time-Delay Systems with Multiple Time-Varying Delays

    Science.gov (United States)

    Park, Gwang-Seok; Choi, Ho-Lim

    In this letter, delay-dependent stability criterion for linear time-delay systems with multiple time varying delays is proposed by employing the Lyapunov-Krasovskii functional approach and integral inequality. By the N-segmentation of delay length, we obtain less conservative results on the delay bounds which guarantee the asymptotic stability of the linear time-delay systems with multiple time varying delays. Simulation results show that the proposed stability criteria are less conservative than several other existing criteria.

  19. Numerical simulation of time delays in light induced ionization

    CERN Document Server

    Su, Jing; Becker, Andreas; Jaroń-Becker, Agnieszka

    2012-01-01

    We apply a fundamental definition of time delay, as the difference between the time a particle spends within a finite region of a potential and the time a free particle spends in the same region, to determine results for photoionization of an electron by an extreme ultraviolet (XUV) laser field using numerical simulations on a grid. Our numerical results are in good agreement with those of the Wigner-Smith time delay, obtained as the derivative of the phase shift of the scattering wave packet with respect to its energy, for the short-range Yukawa potential. In case of the Coulomb potential we obtain time delays for any finite region, while - as expected - the results do not converge as the size of the region increases towards infinity. The impact of an ultrashort near-infrared probe pulse on the time delay is analyzed for both the Yukawa as well as the Coulomb potential and is found to be small for intensities below $10^{13}$ W/cm$^2$.

  20. Chaos in the delay logistic equation with discontinuous delays

    International Nuclear Information System (INIS)

    This paper analyzes a delay logistic equation which models a feedback control problem. Interval map associated to the system is derived. By calculating Lyapunov exponent, we indicate stable orbit and chaotic phenomenon respectively. The results are verified through computer simulation. We identify the parameter which controls the dynamics.

  1. Intuitionistic Fuzzy Generalized Beta Closed Mappings

    OpenAIRE

    D. Jayanthi

    2014-01-01

    In this paper we introduce intuitionistic fuzzy generalized beta closed mappings and intuitionistic fuzzy generalized beta open mappings. We investigate some of their properties. We also introduce intuitionistic fuzzy M-generalized beta closed mappings as well as intuitionistic fuzzy M-generalized beta open mappings. We provide the relation between intuitionistic fuzzy M-generalized beta closed mappings and intuitionistic fuzzy generalized beta closed mappings.

  2. Derivatives of the Incomplete Beta Function

    Directory of Open Access Journals (Sweden)

    Robert J. Boik

    1998-03-01

    Full Text Available The incomplete beta function is defined as where Beta(p, q is the beta function. Dutka (1981 gave a history of the development and numerical evaluation of this function. In this article, an algorithm for computing first and second derivatives of Ix,p,q with respect to p and q is described. The algorithm is useful, for example, when fitting parameters to a censored beta, truncated beta, or a truncated beta-binomial model.

  3. Derivatives of the Incomplete Beta Function

    OpenAIRE

    Robison-Cox, James F.; Robert J. Boik

    1998-01-01

    The incomplete beta function is defined as where Beta(p, q) is the beta function. Dutka (1981) gave a history of the development and numerical evaluation of this function. In this article, an algorithm for computing first and second derivatives of Ix,p,q with respect to p and q is described. The algorithm is useful, for example, when fitting parameters to a censored beta, truncated beta, or a truncated beta-binomial model.

  4. Importance of delayed neutrons in nuclear research

    International Nuclear Information System (INIS)

    The report presents a comprehensive review of the uses ofβ-, n delayed neutrons in nuclear research with special emphasis on energy spectra and reactor applications. The review covers the following aspects : (1) delayed neutron in reactor analysis, (2) absolute delayed neutron yield, (3) delayed neutron decay constants, (4) delayed neutron energy spectra and their importance in high accuracy criticality calculations and precise evaluation of reactor kinetics characteristics, particularly fast breeders, (5) a chronological account of the developments in the measurement of delayed neutron energy spectra, both aggregate (composite) and from individual fission product isotopes during the last fifty years or so, (6) major spectrometry techniques for measuring delayed neutron energy spectra, (7) spectral analysis, (8) calculations of delayed neutron energy spectra from precursor data, and (9) sensitivity analysis of fast reactor dynamic behaviour to delayed neutron energy spectra. Finally the report recommends a number of areas for future research work on delayed neutrons. (author). refs., 49 figs., 10 tabs

  5. Preparation and evaluation of delayed release aceclofenac microspheres

    OpenAIRE

    Radhika Parasuram; Luqman Moidutty; Borkhataria Chetan

    2008-01-01

    Delayed release microspheres of aceclofenac were formulated using an enteric polymer, cellulose acetate phthalate (CAP) prepared by solvent evaporation technique. The effects of various other modern enteric polymers such as hydroxyl propyl methyl cellulose phthalate (HPMCP), Eudragit L 100, and Eudragit S -100 on the release of aceclofenac from the CAP microspheres have been evaluated. The microspheres were characterized for particle size, scanning electron microscopy (SEM), percentage yield,...

  6. Coherent Pattern Prediction in Swarms of Delay-Coupled Agents

    Science.gov (United States)

    Mier-Y-Teran-Romero, Luis; Forgoston, Eric; Scwartz, Ira

    2013-03-01

    We consider a general swarm model of self-propelling particles interacting through a pairwise potential in the presence of a fixed communication time delay. Previous work has shown that swarms with communication time delays and noise may display pattern transitions that depend on the size of the coupling amplitude. We extend these results by completely unfolding the bifurcation structure of the mean field approximation. Our analysis reveals a direct correspondence between the different dynamical behaviors found in different regions of the coupling-time delay plane with the different classes of simulated coherent swarm patterns. We derive the spatio-temporal scales of the swarm structures, and also demonstrate how the complicated interplay of coupling strength, time delay, noise intensity, and choice of initial conditions can affect the swarm. In addition, when adding noise to the system, we find that for sufficiently large values of the coupling strength and/or the time delay, there is a noise intensity threshold that forces a transition of the swarm from a misaligned state into an aligned state. We show that this alignment transition exhibits hysteresis when the noise intensity is taken to be time dependent. Office of Naval Research, NIH (LMR and IBS) and NRL (EF)

  7. Noise Induced Pattern Switching in Randomly Distributed Delayed Swarms.

    Science.gov (United States)

    Lindley, Brandon; Mier-Y-Teran-Romero, Luis; Schwartz, Ira B

    2013-01-01

    We study the effects of noise on the dynamics of a system of coupled self-propelling particles in the case where the coupling is time-delayed, and the delays are discrete and randomly generated. Previous work has demonstrated that the stability of a class of emerging patterns depends upon all moments of the time delay distribution, and predicts their bifurcation parameter ranges. Near the bifurcations of these patterns, noise may induce a transition from one type of pattern to another. We study the onset of these noise-induced swarm re-organizations by numerically simulating the system over a range of noise intensities and for various distributions of the delays. Interestingly, there is a critical noise threshold above which the system is forced to transition from a less organized state to a more organized one. We explore this phenomenon by quantifying this critical noise threshold, and note that transition time between states varies as a function of both the noise intensity and delay distribution. PMID:25382931

  8. Time delay due to spin inside a rotating shell

    International Nuclear Information System (INIS)

    In a previous paper, we have shown that when different images of the same source are observed at a far point by gravitational lensing, there may be an appreciable time delay between these images due to the spin of the central body. In this paper, we derive the time delay in the travel time of massless particles, e.g., photons, propagating inside a massive rotating shell. We analyse this time delay, due to the spin of a shell, in the case when two or more images of the same source, whose photons travel inside a rotating massive shell, are observed at a far point by gravitational lensing. We show that there may be an appreciable time delay due to the spin of the shell. In particular, we consider some astrophysical configurations: a typical rotating galaxy and a typical rotating cluster, or super-cluster of galaxies; this effect might be large enough to be detected at Earth. Thus, this phenomenon should be taken into account in the modelling of the time delay of different images from gravitational lensing and might be detectable in some gravitational-lensing images

  9. Status and perspectives of double beta decay searches

    International Nuclear Information System (INIS)

    Double beta decay is a very rare nuclear decay characterised by a change of 2 units the ordering number Z while leaving the mass number A constant. It can basically occur in two modes, with the emission of two electrons and two anti-neutrinos or the emission of two electrons only. The neutrinoless double beta decay of nuclei is not allowed in the Standard Model and is of outstanding importance for neutrino physics. It can only occur if a neutrino is its own antiparticle and if it has a non-vanishing rest mass. After a general introduction into double beta decay, the talk focusses on the current experimental searches and results and their implications for particle physics. An outlook towards future projects and the involved challenges is given. This includes a discussion on nuclear matrix elements and possible supporting experimental activities.

  10. Effects of beta/gamma radiation on nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Weber, W.J. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-07-01

    A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted {beta}-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of {beta}/{gamma} radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author)

  11. Beta-decay properties of $^{25}$Si and $^{26}$P

    CERN Document Server

    Thomas, J C; Äystö, J; Béraud, R; Blank, B; Canchel, G; Czajkowski, S; Dendooven, P; Ensallem, A; Giovinazzo, J; Guillet, N; Honkanen, J; Jokinen, A; Laird, A M; Lewitowicz, M; Longour, C; De Santos, F O; Peräjärvi, K; democrite-00023307, ccsd

    2004-01-01

    The $\\beta$-decay properties of the neutron-deficient nuclei $^{25}$Si and $^{26}$P have been investigated at the GANIL/LISE3 facility by means of charged-particle and $\\gamma$-ray spectroscopy. The decay schemes obtained and the Gamow-Teller strength distributions are compared to shell-model calculations based on the USD interaction. B(GT) values derived from the absolute measurement of the $\\beta$-decay branching ratios give rise to a quenching factor of the Gamow-Teller strength of 0.6. A precise half-life of 43.7 (6) ms was determined for $^{26}$P, the $\\beta$- (2)p decay mode of which is described.

  12. Nuclear matrix elements for double-{\\beta} decay

    CERN Document Server

    Barea, J; Iachello, F; 10.1103/PhysRevC.87.014315

    2013-01-01

    Background: Direct determination of the neutrino mass through double-$\\beta$ decay is at the present time one of the most important areas of experimental and theoretical research in nuclear and particle physics. Purpose: We calculate nuclear matrix elements for the extraction of the average neutrino mass in neutrinoless double-$\\beta$ decay. Methods: The microscopic interacting boson model (IBM-2) is used. Results: Nuclear matrix elements in the closure approximation are calculated for $^{48}$Ca, $^{76}$Ge, $^{82}$Se, $^{96}$Zr, $^{100}$Mo, $^{110}$Pd, $^{116}$Cd, $^{124}$Sn, $^{128}$Te, $^{130}$Te, $^{148}$Nd, $^{150}$Nd, $^{154}$Sm, $^{160}$Gd, and $^{198}$Pt decay. Conclusions: Realistic predictions for the expected half-lives in neutrinoless double-$\\beta$ decay with light and heavy neutrino exchange in terms of neutrino masses are made and limits are set from current experiments.

  13. Status and perspectives of double beta decay searches

    Energy Technology Data Exchange (ETDEWEB)

    Zuber, Kai [Inst. fuer Kern- und Teilchenphysik, TU Dresden (Germany)

    2011-07-01

    Double beta decay is a very rare nuclear decay characterised by a change of 2 units the ordering number Z while leaving the mass number A constant. It can basically occur in two modes, with the emission of two electrons and two anti-neutrinos or the emission of two electrons only. The neutrinoless double beta decay of nuclei is not allowed in the Standard Model and is of outstanding importance for neutrino physics. It can only occur if a neutrino is its own antiparticle and if it has a non-vanishing rest mass. After a general introduction into double beta decay, the talk focusses on the current experimental searches and results and their implications for particle physics. An outlook towards future projects and the involved challenges is given. This includes a discussion on nuclear matrix elements and possible supporting experimental activities.

  14. Dynamic Hysteresis Probes High-{\\beta} Nanolaser Emission Regimes

    CERN Document Server

    Pan, Si Hui; Amili, Abdelkrim El; Vallini, Felipe; Fainman, Yeshaiahu

    2016-01-01

    The quest for an integrated light source that promises high energy efficiency and fast modulation for high-performance photonic circuits has led to the development of room-temperature telecom-wavelength nanoscale laser with high spontaneous emission factors, \\beta. The coherence characterization of this type of lasers is inherently difficult with the conventional measurement of output light intensity versus input pump intensity due to the diminishing kink in the measurement curve. We demonstrate the transition from chaotic to coherent emission of a high-{\\beta} pulse-pump metallo-dielectric nanolaser can be determined by examining the width of a second order intensity correlation peak, which shrinks below and broadens above threshold. Photon fluctuation study, first one ever reported for this type of nanolaser, confirms the validity of this measurement technique. Additionally, we show that the width variation above threshold results from the delayed threshold phenomenon, providing the first indirect observati...

  15. High Temperature Stability of Potassium Beta Alumina

    Science.gov (United States)

    Williams, R. M.; Kisor, A.; Ryan, M. A.

    1996-01-01

    None. From Objectives section: Evaluate the stability of potassium beta alumina under potassium AMTEC operating conditions. Evaluate the stability regime in which potassium beta alumina can be fabricated.

  16. Vibration Superposition in Tunnel Blasting with Millisecond Delay

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jun-jie; LOU Xiao-ming; LUO De-pi

    2009-01-01

    According to explosion dynamics and elastic wave theory,the models of particle vibration velocity for simultaneous blasting and millisecond blasting are built.In the models,influential factors such as delay interval and charge quantity,are considered.The calculated vibration velocity is compared with the field test results,which shows that the theoretical values are close to the experimental ones.Meanwhile,the particle vibration velocity decreases quickly with time due to the damping of rock mass and has a harmonic motion,and the particle vibration velocity of millisecond blasting has short interval.The superposition of particle vibration velocities may reduce vibration because of wave interference,or magnify the surrounding rock response to the blasting-induced vibration.

  17. Study of pulse shape discrimination for beta events on the n{sup +} contact with BEGe detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lazzaro, Andrea [Physik-Department E15, Technische Universitaet Muenchen (Germany); UNIMIB, Milano (Italy); Budjas, Dusan; Agostini, Matteo; Schoenert, Stefan [Physik-Department E15, Technische Universitaet Muenchen (Germany)

    2012-07-01

    For the second phase of the GERDA experiment, bare BEGe detectors will be deployed in liquid argon. In the GERDA commissioning runs it was observed that the {sup 42}Ar progeny ({sup 42}K) can create background at Q{sub {beta}{beta}}, if the ions are attracted on the detector surface. Beta particles from {sup 42}K decays (Q{sub {beta}}{approx}3.5 MeV) can penetrate the thick Li layer of the detectors n{sup +} contact surface and generate signals also at Q{sub {beta}{beta}}. With BEGe detectors these events can be identified and discriminated via pulse shape analysis. In this talk we present a study of surface beta events discrimination, using measurements of Sr and Ru sources with detectors in vacuum cryostats and the derived expected background suppression factor for {sup 42}K in LAr.

  18. Is the non observation of neutrinoless double beta decay a question of sensitivity?

    International Nuclear Information System (INIS)

    The hypothetical neutrinoless double beta decay is possible only if the neutrino is a truly neutral particle and if it is massive. A truly neutral particle (e.g. a particle identical with its antiparticle) should have all its algebraic intrinsic properties equal to zero, in particular, its lepton number should be 0. Now, since the neutrino is a lepton, its lepton number should be 1. This contradiction would lead to conclude that neutrinoless double beta decay could not take place in nature. This conclusion is, up to now, in agreement with persistent failures to put this long sought hypothetical key decay into evidence despite huge efforts dedicated to this aim

  19. Is the non-observation of neutrinoless double beta decay a question of sensitivity?

    International Nuclear Information System (INIS)

    Hypothetical neutrinoless double beta decay is possible only if the neutrino is a truly neutral particle and if it is massive. A truly neutral particle (e.g. a particle identical with its antiparticle) should have all its algebraic intrinsic properties equal to zero, in particular, its lepton number should be 0. Now, since the neutrino is a lepton, its lepton number should be 1. This contradiction would lead one to conclude that neutrinoless double beta decay cannot take place in nature. This conclusion is, up to now, in agreement with persistent failures to find evidence for this long sought key hypothetical decay despite huge efforts dedicated to this aim. (author)

  20. Providing Delay Guarantees in Bluetooth

    NARCIS (Netherlands)

    Ait Yaiz, Rachid; Heijenk, Geert; Titsworth, F.

    2003-01-01

    Bluetooth polling, also referred to as Bluetooth MAC scheduling or intra-piconet scheduling, is the mechanism that schedules the traffic between the participants in a Bluetooth network. Hence, this mechanism is highly determining with respect to the delay packets experience in a Bluetooth network. I

  1. Diagnostic Delay in Rheumatoid Arthritis

    DEFF Research Database (Denmark)

    Mølbaek, Karen; Hørslev-Petersen, Kim; Primdahl, Jette

    2016-01-01

    BACKGROUND: To prevent joint damage among patients with rheumatoid arthritis (RA), there is a need to minimize delays from the onset of symptoms until the initiation of appropriate therapy. The present study explored the factors that have an impact on the time it takes for Danish patients with RA...

  2. Deconstructing delayed posttraumatic stress disorder

    NARCIS (Netherlands)

    Smid, G.E.

    2011-01-01

    According to the Diagnostic and Statistical Manual of Mental Disorders, delayed posttraumatic stress disorder (PTSD) must be diagnosed in individuals fulfilling criteria for PTSD if the onset of symptoms is at least six months after the trauma. The purpose of this thesis was to establish the prevale

  3. Local Effects of Delayed Food

    Science.gov (United States)

    Davison, Michael; Baum, William M.

    2007-01-01

    Five pigeons were trained on a procedure in which seven concurrent variable-interval schedules arranged seven different food-rate ratios in random sequence in each session. Each of these components lasted for 10 response-produced food deliveries, and components were separated by 10-s blackouts. We varied delays to food (signaled by blackout)…

  4. Livermore blasted for project delay

    CERN Multimedia

    1999-01-01

    In a 12 page report issued last week, a review committee set up by the University of California has concluded that mismanagement and poor planning are to blame for significant cost overruns and delays in the construction of NIF, the worlds largest laser (1 page).

  5. Early-delayed radiation rhombencephalopathy

    International Nuclear Information System (INIS)

    A 37-year-old woman developed an early-delayed rhombencephalopathy 7 weeks after completing a course of radiotherapy to a glomus jugulare tumour. The clinical features, comprising nystagmus, skew strabismus, unilateral facial weakness, dysarthria and ataxia, are compared with four previously reported patients with this syndrome. (author)

  6. Delayed School Entry in Uganda

    Science.gov (United States)

    Moyi, Peter

    2011-01-01

    Since 1997 Uganda has seen a large increase in school enrolment. Despite this increased enrolment, universal education has remained elusive. Many children enrol in school, but not at the recommended age, and they drop out before completing school. This article focuses on one of these problems--delayed school entry. What household factors are…

  7. Effect of beta blockade and beta stimulation on stage fright.

    Science.gov (United States)

    Brantigan, C O; Brantigan, T A; Joseph, N

    1982-01-01

    Stage fright, physiologically the "fight or flight" reaction, is a disabling condition to the professional musician. Because it is mediated by the sympathetic nervous system, we have investigated the effects of beta blockade on musical performance with propranolol in a double blind fashion and the effects of beta stimulation using terbutaline. Stage fright symptoms were evaluated in two trials, which included a total of 29 subjects, by questionnaire and by the State Trai Anxiety Inventory. Quality of musical performance was evaluated by experienced music critics. Beta blockade eliminates the physical impediments to performance caused by stage fright and even eliminates the dry mouth so frequently encountered. The quality of musical performance as judged by experienced music critics is significantly improved. This effect is achieved without tranquilization. Beta stimulating drugs increase stage fright problems, and should be used in performing musicians only after consideration of the detrimental effects which they may have on musical performance. PMID:6120650

  8. Particle-Particle-String Vertex

    OpenAIRE

    Ishibashi, Nobuyuki

    1996-01-01

    We study a theory of particles interacting with strings. Considering such a theory for Type IIA superstring will give some clue about M-theory. As a first step toward such a theory, we construct the particle-particle-string interaction vertex generalizing the D-particle boundary state.

  9. The Age of Beta Pic

    OpenAIRE

    Navascues, D. Barrado y; Stauffer, J. R.; Song, I.; Caillault, J-P.

    1999-01-01

    We have reanalyzed data for the proposed moving group associated with beta Pic in order to determine if the group (or part of it) is real, and, if so, to derive an improved age estimate for beta Pic. By using new, more accurate proper motions from PPM and Hipparcos and a few new radial velocities, we conclude that on kinematic grounds, two M dwarfs have space motions that coincide with that of beta Pic to within 1 km/s with small error bars. Based on a CM diagram derived from accurate photome...

  10. Smart Beta or Smart Alpha

    DEFF Research Database (Denmark)

    Winther, Kenneth Lillelund; Steenstrup, Søren Resen

    2016-01-01

    that smart beta investing probably will do better than passive market capitalization investing over time, we believe many are coming to a conclusion too quickly regarding active managers. Institutional investors are able to guide managers through benchmarks and risk frameworks toward the same well...... only superior to the common capitalization weighted index but also to their smart beta benchmark, even after cost for value, size, and low volatility funds. We encourage investors to increase the use of smart beta as benchmarks while still obtaining extra performance through active management—a concept...

  11. Experiments on double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Busto, J. [Neuchatel Univ. (Switzerland). Inst. de Physique

    1996-11-01

    The Double Beta Decay, and especially ({beta}{beta}){sub 0{nu}} mode, is an excellent test of Standard Model as well as of neutrino physics. From experimental point of view, a very large number of different techniques are or have been used increasing the sensitivity of this experiments quite a lot (the factor of 10{sup 4} in the last 20 years). In future, in spite of several difficulties, the sensitivity would be increased further, keeping the interest of this very important process. (author) 4 figs., 5 tabs., 21 refs.

  12. Dosimetry of {beta} extensive sources; Dosimetria de fuentes {beta} extensas

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E.L.; Lallena R, A.M. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain)

    2002-07-01

    In this work, we have been studied, making use of the Penelope Monte Carlo simulation code, the dosimetry of {beta} extensive sources in situations of spherical geometry including interfaces. These configurations are of interest in the treatment of the called cranealfaringyomes of some synovia leisure of knee and other problems of interest in medical physics. Therefore, its application can be extended toward problems of another areas with similar geometric situation and beta sources. (Author)

  13. Resistance training & beta-hydroxy-beta-methylbutyrate supplementation on hormones

    OpenAIRE

    Hamid Arazi; Hadi Rohani; Ahmad Ghiasi; Nasrin Abdi Keikanloo

    2015-01-01

    RESUMOIntroduction:In recent years, there was an increased interest on the effects of beta-hydroxy-beta-methylbutyrate (HMB) supplementation on skeletal muscle due to its anti-catabolic effects.Objectives:To investigate the effect of HMB supplementation on body composition, muscular strength and anabolic-catabolic hormones after resistance training.Methods:Twenty amateur male athletes were randomly assigned to supplement and control groups in a double-blind crossover design and participated i...

  14. Development of CaMoO4 crystal scintillators for double beta decay experiment with 100-Mo

    OpenAIRE

    Annenkov, A.N.; Buzanov, O. A.; Danevich, F. A.; Georgadze, A. Sh.; Kim, S K; Kim, H. J.; Kim, Y.D.(Center for Underground Physics, Institute for Basic Science (IBS), Daejon, 305-811, Korea); Kobychev, V. V.; Kornoukhov, V.N.; Korzhik, M.; Lee, J. I.; Missevitch, O; Mokina, V. M.; S. S. Nagorny(INR Kiev); Nikolaiko, A. S.

    2007-01-01

    Energy resolution, alpha/beta ratio, pulse-shape discrimination for gamma rays and alpha particles, temperature dependence of scintillation properties, and radioactive contamination were studied with CaMoO4 crystal scintillators. A high sensitivity experiment to search for neutrinoless double beta decay of 100-Mo by using CaMoO4 scintillators is discussed.

  15. Fast-timing studies of nuclei below $^{68}$Ni populated in the $\\beta$-decay of Mn isotopes

    CERN Multimedia

    Jokinen, A; Simpson, G S; Garcia borge, M J; Turrion nieves, M; Koester, U H; Georgiev, G P; Fraile prieto, L M; Aprahamian, A

    2008-01-01

    We intend to investigate structure of nuclei populated in the $\\beta$-decay of Mn isotopes via the ATD $\\beta\\gamma\\gamma$(t) technique. With this method we will measure dynamic moments in Fe isotopes and their daughters in order to characterize the role of particle-hole excitation across the ${N}$=40 sub-shell closure and the development of collectivity.

  16. Systematic study of the single-state dominance in 2 nu beta beta decay transitions

    CERN Document Server

    Civitarese, O

    1999-01-01

    The single-state-dominance hypothesis (SSDH) states that the decay rates of the two-neutrino double-beta decay are governed by a virtual two-step transition connecting the initial and final ground states through the first 1 sup + state, 1 sup + sub 1 , of the intermediate odd-odd nucleus, for those odd-odd nuclei where the 1 sup + sub 1 state is the ground state. To investigate the validity of the SSDH we have performed a systematical theoretical analysis of all known double-beta-decay transitions where the SSDH conditions are fulfilled. The calculations are based on the quasiparticle randon-phase approximation (QRPA) and the results have been obtained by using realistic single-particle bases and realistic interactions. We have studied the double beta sup - decays of sup 1 sup 0 sup 0 Mo, sup 1 sup 1 sup 0 Pd, sup 1 sup 1 sup 4 Cd, sup 1 sup 1 sup 6 Cd and sup 1 sup 2 sup 8 Te and the double electron-capture transitions in sup 1 sup 0 sup 6 Cd and sup 1 sup 3 sup 6 Ce. The analysis shows that the SSDH is real...

  17. Observation of finite-. beta. MHD phenomena in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, K.M.

    1984-09-01

    Stable high-beta plasmas are required for the tokamak to attain an economical fusion reactor. Recently, intense neutral beam heating experiments in tokamaks have shown new effects on plasma stability and confinement associated with high beta plasmas. The observed spectrum of MHD fluctuations at high beta is clearly dominated by the n = 1 mode when the q = 1 surface is in the plasma. The m/n = 1/1 mode drives other n = 1 modes through toroidal coupling and n > 1 modes through nonlinear coupling. On PDX, with near perpendicular injection, a resonant interaction between the n = 1 internal kink and the trapped fast ions results in loss of beam particles and heating power. Key parameters in the theory are the value of q/sub 0/ and the injection angle. High frequency broadband magnetic fluctuations have been observed on ISX-B and D-III and a correlation with the deterioration of plasma confinement was reported. During enhanced confinement (H-mode) discharges in divertor plasmas, two new edge instabilities were observed, both localized radially near the separatrix. By assembling results from the different tokamak experiments, it is found that the simple theoretical ideal MHD beta limit has not been exceeded. Whether this represents an ultimate tokamak limit or if beta optimized configurations (Dee- or bean-shaped plasmas) can exceed this limit and perhaps enter a second regime of stability remains to be clarified.

  18. Neutrino masses from double-beta decay calculations

    CERN Document Server

    Stoica, S

    2002-01-01

    The neutrinoless double-beta decay (0 nu beta beta) matrix elements (ME) for the nuclei with A = 76, 82, 96, 100, 116, 128, 130 and 136 are compared with four different quasi random phase approximation (QRPA) - based method, i.e. the proton-neutron QRPA (pnQRPA), the renormalized proton-neutron QRPA (pnRQRPA), the full RQRPA and the second-QRPA (SQRPA) and using two single-particle basis. From a comparative analysis of the results we show that the uncertainties in the calculation of the ME can be limited to 50% from their values. Further, taking the most recent available limits for the neutrinoless half-lives, we deduce new upper limits for the neutrino mass parameter. Also, there are estimated for each nucleus scales for the (0 nu beta beta) decay half-lives that the experiments should reach for measuring neutrino masses around 0.39 eV. This value was derived from the first experimental evidence of this mode reported very recently by the Heidelberg-Moscow experiment. These estimation give us an indication on...

  19. Target plasma achievements for unity beta operation in ET

    Science.gov (United States)

    Gourdain, P.-A.; Carter, T. A.; Gauvreau, J.-L.; Grossman, A.; Lafonteese, D. J.; Pace, D. C.; Schmitz, L. W.; Taylor, R. J.

    2003-10-01

    The Electric Tokamak (ET) at UCLA (t_pulse0.3V, B=0.25T) is now in a critical stage of research to exceed the conventional beta limit. The latest program is aiming for 10s long plasma discharges at unity peak beta by means of 2^d harmonic ICRF heating and current profile control. A stable computational MHD high beta path has been found for ET high aspect ratio configuration leading from the Troyon limit to unity beta using an in-house equilibrium code and the DCON stability code. This critical path involves high power ICRF injection (5MW) for targeted plasma heating and ballooning/kink modes stabilization by poloidal rotation. Another major component is high plasma density using core and edge fueling relying on kinetic neutral beam and inboard/outboard gas puff. At this regime current profile control using fast wave current drive, with bootstrap current optimization, will be possible. A magnetic well should develop, leading to high beta plasmas with omnigenous properties. To achieve these goals, a tight feedback system between power and particle injections and plasma diagnostics is mandatory.

  20. Distributed delays stabilize neural feedback systems

    CERN Document Server

    Meyer, Ulrike; Chakrabarty, Saurish; Brandt, Sebastian F; Luksch, Harald; Wessel, Ralf

    2007-01-01

    We consider the effect of distributed delays in neural feedback systems. The avian optic tectum is reciprocally connected with the nucleus isthmi. Extracellular stimulation combined with intracellular recordings reveal a range of signal delays from 4 to 9 ms between isthmotectal elements. This observation together with prior mathematical analysis concerning the influence of a delay distribution on system dynamics raises the question whether a broad delay distribution can impact the dynamics of neural feedback loops. For a system of reciprocally connected model neurons, we found that distributed delays enhance system stability in the following sense. With increased distribution of delays, the system converges faster to a fixed point and converges slower toward a limit cycle. Further, the introduction of distributed delays leads to an increased range of the average delay value for which the system's equilibrium point is stable. The enhancement of stability with increasing delay distribution is caused by the int...