Radiocarbon Dating of an Olive Tree Cross-Section: New Insights on Growth Patterns and Implications for Age Estimation of Olive Trees

Directory of Open Access Journals (Sweden)

Yael Ehrlich

2017-11-01

Full Text Available The age of living massive olive trees is often assumed to be between hundreds and even thousands of years. These estimations are usually based on the girth of the trunk and an extrapolation based on a theoretical annual growth rate. It is difficult to objectively verify these claims, as a monumental tree may not be cut down for analysis of its cross-section. In addition, the inner and oldest part of the trunk in olive trees usually rots, precluding the possibility of carting out radiocarbon analysis of material from the first years of life of the tree. In this work we present a cross-section of an olive tree, previously estimated to be hundreds of years old, which was cut down post-mortem in 2013. The cross-section was radiocarbon dated at numerous points following the natural growth pattern, which was made possible to observe by viewing the entire cross-section. Annual growth rate values were calculated and compared between different radii. The cross-section also revealed a nearly independent segment of growth, which would clearly offset any estimations based solely on girth calculations. Multiple piths were identified, indicating the beginning of branching within the trunk. Different radii were found to have comparable growth rates, resulting in similar estimates dating the piths to the 19th century. The estimated age of the piths represent a terminus ante quem for the age of the tree, as these are piths of separate branches. However, the tree is likely not many years older than the dated piths, and certainly not centuries older. The oldest radiocarbon-datable material in this cross-section was less than 200 years old, which is in agreement with most other radiocarbon dates of internal wood from living olive trees, rarely older than 300 years.

Lower limb muscle volume estimation from maximum cross-sectional area and muscle length in cerebral palsy and typically developing individuals.

Science.gov (United States)

Vanmechelen, Inti M; Shortland, Adam P; Noble, Jonathan J

2018-01-01

Deficits in muscle volume may be a significant contributor to physical disability in young people with cerebral palsy. However, 3D measurements of muscle volume using MRI or 3D ultrasound may be difficult to make routinely in the clinic. We wished to establish whether accurate estimates of muscle volume could be made from a combination of anatomical cross-sectional area and length measurements in samples of typically developing young people and young people with bilateral cerebral palsy. Lower limb MRI scans were obtained from the lower limbs of 21 individuals with cerebral palsy (14.7±3years, 17 male) and 23 typically developing individuals (16.8±3.3years, 16 male). The volume, length and anatomical cross-sectional area were estimated from six muscles of the left lower limb. Analysis of Covariance demonstrated that the relationship between the length*cross-sectional area and volume was not significantly different depending on the subject group. Linear regression analysis demonstrated that the product of anatomical cross-sectional area and length bore a strong and significant relationship to the measured muscle volume (R 2 values between 0.955 and 0.988) with low standard error of the estimates of 4.8 to 8.9%. This study demonstrates that muscle volume may be estimated accurately in typically developing individuals and individuals with cerebral palsy by a combination of anatomical cross-sectional area and muscle length. 2D ultrasound may be a convenient method of making these measurements routinely in the clinic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stroke Volume estimation using aortic pressure measurements and aortic cross sectional area: Proof of concept.

Science.gov (United States)

Kamoi, S; Pretty, C G; Chiew, Y S; Pironet, A; Davidson, S; Desaive, T; Shaw, G M; Chase, J G

2015-08-01

Accurate Stroke Volume (SV) monitoring is essential for patient with cardiovascular dysfunction patients. However, direct SV measurements are not clinically feasible due to the highly invasive nature of measurement devices. Current devices for indirect monitoring of SV are shown to be inaccurate during sudden hemodynamic changes. This paper presents a novel SV estimation using readily available aortic pressure measurements and aortic cross sectional area, using data from a porcine experiment where medical interventions such as fluid replacement, dobutamine infusions, and recruitment maneuvers induced SV changes in a pig with circulatory shock. Measurement of left ventricular volume, proximal aortic pressure, and descending aortic pressure waveforms were made simultaneously during the experiment. From measured data, proximal aortic pressure was separated into reservoir and excess pressures. Beat-to-beat aortic characteristic impedance values were calculated using both aortic pressure measurements and an estimate of the aortic cross sectional area. SV was estimated using the calculated aortic characteristic impedance and excess component of the proximal aorta. The median difference between directly measured SV and estimated SV was -1.4ml with 95% limit of agreement +/- 6.6ml. This method demonstrates that SV can be accurately captured beat-to-beat during sudden changes in hemodynamic state. This novel SV estimation could enable improved cardiac and circulatory treatment in the critical care environment by titrating treatment to the effect on SV.

Methodology series module 3: Cross-sectional studies

Directory of Open Access Journals (Sweden)

Maninder Singh Setia

2016-01-01

Full Text Available Cross-sectional study design is a type of observational study design. In a cross-sectional study, the investigator measures the outcome and the exposures in the study participants at the same time. Unlike in case–control studies (participants selected based on the outcome status or cohort studies (participants selected based on the exposure status, the participants in a cross-sectional study are just selected based on the inclusion and exclusion criteria set for the study. Once the participants have been selected for the study, the investigator follows the study to assess the exposure and the outcomes. Cross-sectional designs are used for population-based surveys and to assess the prevalence of diseases in clinic-based samples. These studies can usually be conducted relatively faster and are inexpensive. They may be conducted either before planning a cohort study or a baseline in a cohort study. These types of designs will give us information about the prevalence of outcomes or exposures; this information will be useful for designing the cohort study. However, since this is a 1-time measurement of exposure and outcome, it is difficult to derive causal relationships from cross-sectional analysis. We can estimate the prevalence of disease in cross-sectional studies. Furthermore, we will also be able to estimate the odds ratios to study the association between exposure and the outcomes in this design.

Methodology Series Module 3: Cross-sectional Studies.

Science.gov (United States)

Setia, Maninder Singh

2016-01-01

Cross-sectional study design is a type of observational study design. In a cross-sectional study, the investigator measures the outcome and the exposures in the study participants at the same time. Unlike in case-control studies (participants selected based on the outcome status) or cohort studies (participants selected based on the exposure status), the participants in a cross-sectional study are just selected based on the inclusion and exclusion criteria set for the study. Once the participants have been selected for the study, the investigator follows the study to assess the exposure and the outcomes. Cross-sectional designs are used for population-based surveys and to assess the prevalence of diseases in clinic-based samples. These studies can usually be conducted relatively faster and are inexpensive. They may be conducted either before planning a cohort study or a baseline in a cohort study. These types of designs will give us information about the prevalence of outcomes or exposures; this information will be useful for designing the cohort study. However, since this is a 1-time measurement of exposure and outcome, it is difficult to derive causal relationships from cross-sectional analysis. We can estimate the prevalence of disease in cross-sectional studies. Furthermore, we will also be able to estimate the odds ratios to study the association between exposure and the outcomes in this design.

Consumers’ estimation of calorie content at fast food restaurants: cross sectional observational study

OpenAIRE

Block, Jason Perry; Condon, Suzanne K; Kleinman, Ken Paul; Mullen, Jewel; Linakis, Stephanie; Rifas-Shiman, Sheryl Lynn; Gillman, Matthew William

2013-01-01

Objective: To investigate estimation of calorie (energy) content of meals from fast food restaurants in adults, adolescents, and school age children. Design: Cross sectional study of repeated visits to fast food restaurant chains. Setting: 89 fast food restaurants in four cities in New England, United States: McDonald’s, Burger King, Subway, Wendy’s, KFC, Dunkin’ Donuts. Participants: 1877 adults and 330 school age children visiting restaurants at dinnertime (evening meal) in 2010 and 2011; 1...

Defining and Estimating Healthy Aging in Spain: A Cross-sectional Study.

Science.gov (United States)

Rodriguez-Laso, Angel; McLaughlin, Sara J; Urdaneta, Elena; Yanguas, Javier

2018-03-19

Using an operational continuum of healthy aging developed by U.S. researchers, we sought to estimate the prevalence of healthy aging among older Spaniards, inform the development of a definition of healthy aging in Spain, and foster cross-national research on healthy aging. The ELES pilot study is a nationwide, cross-sectional survey of community-dwelling Spaniards 50 years and older. The prevalence of healthy aging was calculated for the 65 and over population using varying definitions. To evaluate their validity, we examined the association of healthy aging with the 8 foot up & go test, quality of life scores and self-perceived health using multiple linear and logistic regression. The estimated prevalence of healthy aging varied across the operational continuum, from 4.5% to 49.2%. Prevalence figures were greater for men and those aged 65 to 79 years and were higher than in the United States. Predicted mean physical performance scores were similar for 3 of the 4 definitions, suggesting that stringent definitions of healthy aging offer little advantage over a more moderate one. Similar to U.S. researchers, we recommend a definition of healthy aging that incorporates measures of functional health and limiting disease as opposed to definitions requiring the absence of all disease in studies designed to assess the effect of policy initiatives on healthy aging.

Theoretical estimates of supernova-neutrino cross sections for the stable even-even lead isotopes: Charged-current reactions

Science.gov (United States)

Almosly, W.; Carlsson, B. G.; Suhonen, J.; Toivanen, J.; Ydrefors, E.

2016-10-01

A detailed study of the charged-current supernova electron neutrino and electron antineutrino scattering off the stable even-mass lead isotopes A =204 , 206, and 208 is reported in this work. The proton-neutron quasiparticle random-phase approximation (pnQRPA) is adopted to construct the nuclear final and initial states. Three different Skyrme interactions are tested for their isospin and spin-isospin properties and then applied to produce (anti)neutrino-nucleus scattering cross sections for (anti)neutrino energies below 80 MeV. Realistic estimates of the nuclear responses to supernova (anti)neutrinos are computed by folding the computed cross sections with a two-parameter Fermi-Dirac distribution of the electron (anti)neutrino energies. The computed cross sections are compared with earlier calculations and the analyses are extended to take into account the effects coming from the neutrino oscillations.

Measurements of fission cross-sections. Chapter 4

International Nuclear Information System (INIS)

James, G.D.

1981-01-01

The steps involved in the measurement of fission cross sections are summarized and the range of techniques available are considered. Methods of fission detection are described with particular emphasis on the neutron energy dependent properties of the fission process and the details of fragment energy loss which can lead to energy-dependent changes in detector efficiency. Selected examples of fission cross-section measurements are presented and methods of data reduction, storage, analysis and evaluation, are examined. Finally requested accuracies for fission cross section data are compared to estimated available accuracies. (U.K.)

Fragmentation cross sections outside the limiting-fragmentation regime

CERN Document Server

Sümmerer, K

2003-01-01

The empirical parametrization of fragmentation cross sections, EPAX, has been successfully applied to estimate fragment production cross sections in reactions of heavy ions at high incident energies. It is checked whether a similar parametrization can be found for proton-induced spallation around 1 GeV, the range of interest for ISOL-type RIB facilities. The validity of EPAX for medium-energy heavy-ion induced reactions is also checked. Only a few datasets are available, but in general EPAX predicts the cross sections rather well, except for fragments close to the projectile, where the experimental cross sections are found to be larger.

Estimated 55Mn and 90Zr cross section covariances in the fast neutron energy region

International Nuclear Information System (INIS)

Pigni, M.T.; Herman, M.; Oblozinsky, P.

2008-01-01

We completed estimates of neutron cross section covariances for 55 Mn and 90 Zr, from keV range to 25 MeV, considering the most important reaction channels, total, elastic, inelastic, capture, and (n,2n). The nuclear reaction model code EMPIRE was used to calculate sensitivity to model parameters by perturbation of parameters that define the optical model potential, nuclear level densities and strength of the pre-equilibrium emission. The sensitivity analysis was performed with the set of parameters which reproduces the ENDF/B-VII.0 cross sections. The experimental data were analyzed and both statistical and systematic uncertainties were extracted from almost 30 selected experiments. Then, the Bayesian code KALMAN was used to combine the sensitivity analysis and the experiments to obtain the evaluated covariance matrices

Estimated 55Mn and 90Zr cross section covariances in the fast neutron energy region

Energy Technology Data Exchange (ETDEWEB)

Pigni,M.T.; Herman, M.; Oblozinsky, P.

2008-06-24

We completed estimates of neutron cross section covariances for {sup 55}Mn and {sup 90}Zr, from keV range to 25 MeV, considering the most important reaction channels, total, elastic, inelastic, capture, and (n,2n). The nuclear reaction model code EMPIRE was used to calculate sensitivity to model parameters by perturbation of parameters that define the optical model potential, nuclear level densities and strength of the pre-equilibrium emission. The sensitivity analysis was performed with the set of parameters which reproduces the ENDF/B-VII.0 cross sections. The experimental data were analyzed and both statistical and systematic uncertainties were extracted from almost 30 selected experiments. Then, the Bayesian code KALMAN was used to combine the sensitivity analysis and the experiments to obtain the evaluated covariance matrices.

Calculation of the intermediate energy activation cross section

Energy Technology Data Exchange (ETDEWEB)

Furihata, Shiori; Yoshizawa, Nobuaki [Mitsubishi Research Inst., Inc., Tokyo (Japan)

1997-03-01

We discussed the activation cross section in order to predict accurately the activation of soil around an accelerator with high energy and strong intensity beam. For the assessment of the accuracy of activation cross sections estimated by a numerical model, we compared the calculated cross section with various experimental data, for Si(p,x){sup 22}Na, Al(p,x){sup 22}Na, Fe(p,x){sup 22}Na, Si(p,x){sup 7}Be, O(p,x){sup 3}H, Al(p,x){sup 3}H and Si(p,x){sup 3}H reactions. We used three computational codes, i.e., quantum molecular dynamics (QMD) plus statistical decay model (SDM), HETC-3STEP and the semiempirical method developed by Silberberg et.al. It is observed that the codes are accurate above 1GeV, except for {sup 7}Be production. We also discussed the difference between the activation cross sections of proton- and neutron-induced reaction. For the incident energy at 40MeV, it is found that {sup 3}H production cross sections of neutron-induced reaction are ten times as large as those of proton-induced reaction. It is also observed that the choice of the activation cross sections seriously affects to the estimate of saturated radioactivity, if the maximum energy of neutron flux is below 100MeV. (author)

Using multiplicity as a fractional cross-section estimation for centrality in PHOBOS

Science.gov (United States)

Hollis, Richard S.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holylnski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Wozniak, K.; Wyslouch, B.; PHOBOS Collaboration

2005-01-01

Collision centrality is a valuable parameter used in relativistic nuclear physics which relates to geometrical quantities such as the number of participating nucleons. PHOBOS utilizes a multiplicity measurement as a means to estimate fractional cross-section of a collision event-by-event. From this, the centrality of this collision can be deduced. The details of the centrality determination depend both on the collision system and collision energy. Presented here are the techniques developed over the course of the RHIC program that are used by PHOBOS to extract the centrality. Possible biases that have to be overcome before a final measurement can be interpreted are discussed.

Estimating infection attack rates and severity in real time during an influenza pandemic: analysis of serial cross-sectional serologic surveillance data.

Directory of Open Access Journals (Sweden)

Joseph T Wu

2011-10-01

Full Text Available In an emerging influenza pandemic, estimating severity (the probability of a severe outcome, such as hospitalization, if infected is a public health priority. As many influenza infections are subclinical, sero-surveillance is needed to allow reliable real-time estimates of infection attack rate (IAR and severity.We tested 14,766 sera collected during the first wave of the 2009 pandemic in Hong Kong using viral microneutralization. We estimated IAR and infection-hospitalization probability (IHP from the serial cross-sectional serologic data and hospitalization data. Had our serologic data been available weekly in real time, we would have obtained reliable IHP estimates 1 wk after, 1-2 wk before, and 3 wk after epidemic peak for individuals aged 5-14 y, 15-29 y, and 30-59 y. The ratio of IAR to pre-existing seroprevalence, which decreased with age, was a major determinant for the timeliness of reliable estimates. If we began sero-surveillance 3 wk after community transmission was confirmed, with 150, 350, and 500 specimens per week for individuals aged 5-14 y, 15-19 y, and 20-29 y, respectively, we would have obtained reliable IHP estimates for these age groups 4 wk before the peak. For 30-59 y olds, even 800 specimens per week would not have generated reliable estimates until the peak because the ratio of IAR to pre-existing seroprevalence for this age group was low. The performance of serial cross-sectional sero-surveillance substantially deteriorates if test specificity is not near 100% or pre-existing seroprevalence is not near zero. These potential limitations could be mitigated by choosing a higher titer cutoff for seropositivity. If the epidemic doubling time is longer than 6 d, then serial cross-sectional sero-surveillance with 300 specimens per week would yield reliable estimates when IAR reaches around 6%-10%.Serial cross-sectional serologic data together with clinical surveillance data can allow reliable real-time estimates of IAR and

Estimating health expectancies from two cross-sectional surveys: The intercensal method

Directory of Open Access Journals (Sweden)

Michel Guillot

2009-10-01

Full Text Available Health expectancies are key indicators for monitoring the health of populations, as well as for informing debates about compression or expansion of morbidity. However, current methodologies for estimating them are not entirely satisfactory. They are either of limited applicability because of high data requirements (the multistate method or based on questionable assumptions (the Sullivan method. This paper proposes a new method, called the "intercensal" method, which relies on the multistate framework but uses widely available data. The method uses age-specific proportions "healthy" at two successive, independent cross-sectional health surveys, and, together with information on general mortality, solves for the set of transition probabilities that produces the observed sequence of proportions healthy. The system is solved by making realistic parametric assumptions about the age patterns of transition probabilities. Using data from the Health and Retirement Survey (HRS and from the National Health Interview Survey (NHIS, the method is tested against both the multistate method and the Sullivan method. We conclude that the intercensal approach is a promising framework for the indirect estimation of health expectancies.

Evaluation of covariance for 238U cross sections

International Nuclear Information System (INIS)

Kawano, Toshihiko; Nakamura, Masahiro; Matsuda, Nobuyuki; Kanda, Yukinori

1995-01-01

Covariances of 238 U are generated using analytic functions for representation of the cross sections. The covariances of the (n,2n) and (n,3n) reactions are derived with a spline function, while the covariances of the total and the inelastic scattering cross section are estimated with a linearized nuclear model calculation. (author)

Total and ionization cross sections of electron scattering by fluorocarbons

International Nuclear Information System (INIS)

Antony, B K; Joshipura, K N; Mason, N J

2005-01-01

Electron impact total cross sections (50-2000 eV) and total ionization cross sections (threshold to 2000 eV) are calculated for typical plasma etching molecules CF 4 , C 2 F 4 , C 2 F 6 , C 3 F 8 and CF 3 I and the CF x (x 1-3) radicals. The total elastic and inelastic cross sections are determined in the spherical complex potential formalism. The sum of the two gives the total cross section and the total inelastic cross section is used to calculate the total ionization cross sections. The present total and ionization cross sections are found to be consistent with other theories and experimental measurements, where they exist. Our total cross section results for CF x (x = 1-3) radicals presented here are first estimates on these species

Covariance Evaluation Methodology for Neutron Cross Sections

Energy Technology Data Exchange (ETDEWEB)

Herman,M.; Arcilla, R.; Mattoon, C.M.; Mughabghab, S.F.; Oblozinsky, P.; Pigni, M.; Pritychenko, b.; Songzoni, A.A.

2008-09-01

We present the NNDC-BNL methodology for estimating neutron cross section covariances in thermal, resolved resonance, unresolved resonance and fast neutron regions. The three key elements of the methodology are Atlas of Neutron Resonances, nuclear reaction code EMPIRE, and the Bayesian code implementing Kalman filter concept. The covariance data processing, visualization and distribution capabilities are integral components of the NNDC methodology. We illustrate its application on examples including relatively detailed evaluation of covariances for two individual nuclei and massive production of simple covariance estimates for 307 materials. Certain peculiarities regarding evaluation of covariances for resolved resonances and the consistency between resonance parameter uncertainties and thermal cross section uncertainties are also discussed.

Heavy flavour hadro-production cross-sections

CERN Document Server

Wöhri, H K

2003-01-01

Hadro-production data on charm and beauty absolute cross-sections, collected by experiments at CERN, DESY and Fermilab, are reviewed. The measurements, corrected for the 'time evolution' of the branching ratios, are compared to calculations done with Pythia, as a function of the collision energy, using the latest parametrizations of the parton densities. We then estimate some charm and beauty production cross-sections relevant for future measurements, including nuclear effectes in the PDFs. We finish by briefly addressing the relevance, in heavy-ion collisions, of beauty production as feed-down for J/psi production.

The 10B(n,α)7Li cross section

International Nuclear Information System (INIS)

1997-01-01

The data base relevant to an evaluation of the 10 B(n,α) standard cross sections have been improved through interlaboratory collaboration. Changes in the evaluated 10 B(n,α) cross sections resulted form the measurements made since the ENDF/B-VI evaluation have been estimated. 12 refs, 4 figs

Monostatic Radar Cross Section Estimation of Missile Shaped Object Using Physical Optics Method

Science.gov (United States)

Sasi Bhushana Rao, G.; Nambari, Swathi; Kota, Srikanth; Ranga Rao, K. S.

2017-08-01

Stealth Technology manages many signatures for a target in which most radar systems use radar cross section (RCS) for discriminating targets and classifying them with regard to Stealth. During a war target’s RCS has to be very small to make target invisible to enemy radar. In this study, Radar Cross Section of perfectly conducting objects like cylinder, truncated cone (frustum) and circular flat plate is estimated with respect to parameters like size, frequency and aspect angle. Due to the difficulties in exactly predicting the RCS, approximate methods become the alternative. Majority of approximate methods are valid in optical region and where optical region has its own strengths and weaknesses. Therefore, the analysis given in this study is purely based on far field monostatic RCS measurements in the optical region. Computation is done using Physical Optics (PO) method for determining RCS of simple models. In this study not only the RCS of simple models but also missile shaped and rocket shaped models obtained from the cascaded objects with backscatter has been computed using Matlab simulation. Rectangular plots are obtained for RCS in dbsm versus aspect angle for simple and missile shaped objects using Matlab simulation. Treatment of RCS, in this study is based on Narrow Band.

Tachyonic ionization cross sections of hydrogenic systems

Energy Technology Data Exchange (ETDEWEB)

Tomaschitz, Roman [Department of Physics, Hiroshima University, 1-3-1 Kagami-yama, Higashi-Hiroshima 739-8526 (Japan)

2005-03-11

Transition rates for induced and spontaneous tachyon radiation in hydrogenic systems as well as the transversal and longitudinal ionization cross sections are derived. We investigate the interaction of the superluminal radiation field with matter in atomic bound-bound and bound-free transitions. Estimates are given for Ly-{alpha} transitions effected by superluminal quanta in hydrogen-like ions. The tachyonic photoelectric effect is scrutinized, in the Born approximation and at the ionization threshold. The angular maxima occur at different scattering angles in the transversal and longitudinal cross sections, which can be used to sift out longitudinal tachyonic quanta in a photon flux. We calculate the tachyonic ionization and recombination cross sections for Rydberg states and study their asymptotic scaling with respect to the principal quantum number. At the ionization threshold of highly excited states of order n {approx} 10{sup 4}, the longitudinal cross section starts to compete with photoionization, in recombination even at lower levels.

Estimating Total Fusion Cross Sections by Using a Coupled-Channel Method

Energy Technology Data Exchange (ETDEWEB)

Choi, Ki-Seok; Cheoun, Myung-Ki [Soongsil University, Seoul (Korea, Republic of); Kim, K. S. [Korea Aerospace University, Koyang (Korea, Republic of); Kim, T. H.; So, W. Y. [Kangwon National University at Dogye, Samcheok (Korea, Republic of)

2017-01-15

We calculate the total fusion cross sections for the {sup 6}He + {sup 209}Bi, {sup 6}Li + {sup 209}Bi,{sup 9}Be + {sup 208}Pb, {sup 10}Be + {sup 209}Bi, and {sup 11}Li + {sup 208}Pb systems by using a coupled-channel (CC) method and compare the results with the experimental data. In the CC approach for the total fusion cross sections, we exploit a globally determined Wood-Saxon potential with Aky¨uz-Winther parameters and couplings of the ground state to the low-lying excited states in the projectile and the target nuclei. The total fusion cross sections obtained with the CC are compared with those obtained without the CC couplings. The latter approach is tantamount to a one-dimensional barrier penetration model. Finally, our approach is applied to understand new data for the {sup 11}Li+{sup 208}Pb system. Possible ambiguities inherent in those approaches are discussed in detail for further applications to the fusion system of halo and/or neutron-rich nuclei.

Use of nuclear reaction models in cross section calculations

International Nuclear Information System (INIS)

Grimes, S.M.

1975-03-01

The design of fusion reactors will require information about a large number of neutron cross sections in the MeV region. Because of the obvious experimental difficulties, it is probable that not all of the cross sections of interest will be measured. Current direct and pre-equilibrium models can be used to calculate non-statistical contributions to neutron cross sections from information available from charged particle reaction studies; these are added to the calculated statistical contribution. Estimates of the reliability of such calculations can be derived from comparisons with the available data. (3 tables, 12 figures) (U.S.)

Displacement cross sections and PKA spectra: tables and applications

International Nuclear Information System (INIS)

Doran, D.G.; Graves, N.J.

1976-12-01

Damage energy cross sections to 20 MeV are given for aluminum, vanadium, chromium, iron, nickel, copper, zirconium, niobium, molybdenum, tantalum, tungsten, lead, and 18Cr10Ni stainless steel. They are based on ENDF/B-IV nuclear data and the Lindhard energy partition model. Primary knockon atom (PKA) spectra are given for aluminum, iron, niobium, tantalum, and lead for neutron energies up to 15 MeV at approximately one-quarter lethargy intervals. The contributions of various reactions to both the displacement cross sections (taken to be proportional to the damage energy cross sections) and the PKA spectra are presented graphically. Spectral-averaged values of the displacement cross sections are given for several spectra, including approximate maps for the Experimental Breeder Reactor-II (EBR-II) and several positions in the Fast Test Reactor (FTR). Flux values are included to permit estimation of displacement rates. Graphs show integral PKA spectra for the five metals listed above for neutron spectra corresponding to locations in the EBR-II, the High Flux Isotope Reactor (HFIR), and a conceptual fusion reactor (UWMAK-I). Detailed calculations are given only for cases not previously documented. Uncertainty estimates are included

Cross section sensitivity study for fusion blankets incorporating lead neutron multiplier

International Nuclear Information System (INIS)

Pelloni, S.; Cheng, E.T.

1983-01-01

In the recent European INTOR design, lead has been considered for incorporation in the blanket as either an explicit or implicit neutron multiplier. The blanket employs either Li 2 SiO 3 or Li 17 Pb 83 as tritium breeding material. Nucleonic analysis was performed for this blanket using the DLC37 and DLC41 cross section libraries. The reaction rates were estimated using the reaction cross sections provided with both libraries. In addition to that, they were estimated using the MACKLIB-IV response library. The calculated tritium breeding ratio was found to be 5% less and 15% more in the calculations with DLC41 and DLC41 plus MACKLIB-IV libraries, respectively, than in the calculation with the DLC37 library. The Fe, Pb, and Li cross sections given by the ENDF/B-IV and V were reviewed. A sensitivity study of these cross section uncertainties shows that the tritium breeding ratio is relatively insensitive to the above mentioned partial cross sections. The calculated tritium breeding ratio can be known within +-2%. (Auth.)

Measurement of 76Se and 78Se (γ, n) cross sections

International Nuclear Information System (INIS)

Kitatani, Fumito; Harada, Hideo; Goko, Shinji; Utsunomiya, Hiroaki; Akimune, Hidetoshi; Toyokawa, Hiroyuki; Yamada, Kawakatsu

2011-01-01

The (γ, n) cross sections of Se isotopes ( 76 Se, 78 Se) were measured to supply fundamental data for estimating the inverse reaction cross section, i.e., the 79 Se(n, γ) 80 Se cross section. The enriched samples and a reference 197 Au sample were irradiated with laser-Compton scattering (LCS) γ-rays. The excitation function of each (γ, n) cross section was determined for the energy range from each near neutron separation energy to the threshold energy of (γ, 2n) reaction. The energy point corresponding to each cross section was deduced using the accurately determined energy distribution of LCS γ-rays. Systematic (γ, n) cross sections for Se isotopes including 80 Se were compared with those calculated by using a statistical model calculation code TALYS. (author)

Electron-impact ionization cross section of rubidium

International Nuclear Information System (INIS)

Kim, Y.; Migdalek, J.; Siegel, W.; Bieron, J.

1998-01-01

A theoretical model for electron-impact ionization cross section has been applied to Rb and the theoretical cross section (from the threshold to 1 keV in incident energy) is in good agreement with the recent experimental data obtained using Rb atoms trapped in a magneto-optical trap. The theoretical model, called the binary-encounter endash dipole (BED) model, combines a modified Mott cross section with the high-energy behavior of Born cross sections. To obtain the continuum dipole oscillator strength df/dE of the 5s electron required in the BED model, we used Dirac-Fock continuum wave functions with a core polarization potential that reproduced the known position of the Cooper minimum in the photoionization cross section. For inner-shell ionization, we used a simpler version of df/dE, which retained the hydrogenic shape. The contributions of the 4p→4d, 5s, and 5p autoionizing excitations were estimated using the plane-wave Born approximation. As a by-product, we also present the dipole oscillator strengths for the 5s→np 1/2 and 5s→np 3/2 transitions for high principal quantum numbers n near the ionization threshold obtained from the Dirac-Fock wave functions with the same core polarization potential as that used for the continuum wave functions. copyright 1998 The American Physical Society

Estimating the incidence of influenza-virus infections in Dutch weaned piglets using blood samples from a cross-sectional study.

NARCIS (Netherlands)

Loeffen, W.L.A.; Nodelijk, G.; Heinen, P.P.; Leengoed, van L.A.M.G.; Hunneman, W.A.; Verheijden, J.H.M.

2003-01-01

A cross-sectional study was carried out on 32 Dutch breeding herds to estimate the incidence of influenza-virus infections in piglets before the start of the finishing period, at the age of approximately 10 weeks. Longitudinal studies on two herds (8 and 10 litters, respectively) were done to obtain

Evaluation of the neutron and gamma-ray production cross-sections for 55Mn

International Nuclear Information System (INIS)

Takahashi, H.

1974-11-01

The evaluation of neutron and gamma production cross sections for manganese-55 from 1.0 (10) -5 eV to 20.0 MeV for ENDF/ B-IV is summarized. Included are resonance parameters, neutron cross sections, angular and energy distribution of secondary neutrons, gamma multiplicities and transition probability array, gamma angular and energy distributions, nuclear model calculations, uncertainty estimates of cross sections, and evaluated cross sections. (U.S.)

Fission neutron spectrum averaged cross sections for threshold reactions on arsenic

International Nuclear Information System (INIS)

Dorval, E.L.; Arribere, M.A.; Kestelman, A.J.; Comision Nacional de Energia Atomica, Cuyo Nacional Univ., Bariloche; Ribeiro Guevara, S.; Cohen, I.M.; Ohaco, R.A.; Segovia, M.S.; Yunes, A.N.; Arrondo, M.; Comision Nacional de Energia Atomica, Buenos Aires

2006-01-01

We have measured the cross sections, averaged over a 235 U fission neutron spectrum, for the two high threshold reactions: 75 As(n,p) 75 mGe and 75 As(n,2n) 74 As. The measured averaged cross sections are 0.292±0.022 mb, referred to the 3.95±0.20 mb standard for the 27 Al(n,p) 27 Mg averaged cross section, and 0.371±0.032 mb referred to the 111±3 mb standard for the 58 Ni(n,p) 58m+g Co averaged cross section, respectively. The measured averaged cross sections were also evaluated semi-empirically by numerically integrating experimental differential cross section data extracted for both reactions from the current literature. The calculations were performed for four different representations of the thermal-neutron-induced 235 U fission neutron spectrum. The calculated cross sections, though depending on analytical representation of the flux, agree with the measured values within the estimated uncertainties. (author)

Models for Pooled Time-Series Cross-Section Data

Directory of Open Access Journals (Sweden)

Lawrence E Raffalovich

2015-07-01

Full Text Available Several models are available for the analysis of pooled time-series cross-section (TSCS data, defined as “repeated observations on fixed units” (Beck and Katz 1995. In this paper, we run the following models: (1 a completely pooled model, (2 fixed effects models, and (3 multi-level/hierarchical linear models. To illustrate these models, we use a Generalized Least Squares (GLS estimator with cross-section weights and panel-corrected standard errors (with EViews 8 on the cross-national homicide trends data of forty countries from 1950 to 2005, which we source from published research (Messner et al. 2011. We describe and discuss the similarities and differences between the models, and what information each can contribute to help answer substantive research questions. We conclude with a discussion of how the models we present may help to mitigate validity threats inherent in pooled time-series cross-section data analysis.

Correction of sampling bias in a cross-sectional study of post-surgical complications.

Science.gov (United States)

Fluss, Ronen; Mandel, Micha; Freedman, Laurence S; Weiss, Inbal Salz; Zohar, Anat Ekka; Haklai, Ziona; Gordon, Ethel-Sherry; Simchen, Elisheva

2013-06-30

Cross-sectional designs are often used to monitor the proportion of infections and other post-surgical complications acquired in hospitals. However, conventional methods for estimating incidence proportions when applied to cross-sectional data may provide estimators that are highly biased, as cross-sectional designs tend to include a high proportion of patients with prolonged hospitalization. One common solution is to use sampling weights in the analysis, which adjust for the sampling bias inherent in a cross-sectional design. The current paper describes in detail a method to build weights for a national survey of post-surgical complications conducted in Israel. We use the weights to estimate the probability of surgical site infections following colon resection, and validate the results of the weighted analysis by comparing them with those obtained from a parallel study with a historically prospective design. Copyright © 2012 John Wiley & Sons, Ltd.

Standard cross-section data

International Nuclear Information System (INIS)

Carlson, A.D.

1984-01-01

The accuracy of neutron cross-section measurement is limited by the uncertainty in the standard cross-section and the errors associated with using it. Any improvement in the standard immediately improves all cross-section measurements which have been made relative to that standard. Light element, capture and fission standards are discussed. (U.K.)

Ecological Panel Inference from Repeated Cross Sections

NARCIS (Netherlands)

Pelzer, Ben; Eisinga, Rob; Franses, Philip Hans

2004-01-01

This chapter presents a Markov chain model for the estimation of individual-level binary transitions from a time series of independent repeated cross-sectional (RCS) samples. Although RCS samples lack direct information on individual turnover, it is demonstrated here that it is possible with these

Relationship between body mass, lean mass, fat mass, and limb bone cross-sectional geometry: Implications for estimating body mass and physique from the skeleton.

Science.gov (United States)

Pomeroy, Emma; Macintosh, Alison; Wells, Jonathan C K; Cole, Tim J; Stock, Jay T

2018-05-01

Estimating body mass from skeletal dimensions is widely practiced, but methods for estimating its components (lean and fat mass) are poorly developed. The ability to estimate these characteristics would offer new insights into the evolution of body composition and its variation relative to past and present health. This study investigates the potential of long bone cross-sectional properties as predictors of body, lean, and fat mass. Humerus, femur and tibia midshaft cross-sectional properties were measured by peripheral quantitative computed tomography in sample of young adult women (n = 105) characterized by a range of activity levels. Body composition was estimated from bioimpedance analysis. Lean mass correlated most strongly with both upper and lower limb bone properties (r values up to 0.74), while fat mass showed weak correlations (r ≤ 0.29). Estimation equations generated from tibial midshaft properties indicated that lean mass could be estimated relatively reliably, with some improvement using logged data and including bone length in the models (minimum standard error of estimate = 8.9%). Body mass prediction was less reliable and fat mass only poorly predicted (standard errors of estimate ≥11.9% and >33%, respectively). Lean mass can be predicted more reliably than body mass from limb bone cross-sectional properties. The results highlight the potential for studying evolutionary trends in lean mass from skeletal remains, and have implications for understanding the relationship between bone morphology and body mass or composition. © 2018 The Authors. American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

Cross-sectional dependence in panel data analysis

NARCIS (Netherlands)

Sarafidis, V.; Wansbeek, T.J.

2012-01-01

This article provides an overview of the existing literature on panel data models with error cross-sectional dependence (CSD). We distinguish between weak and strong CSD and link these concepts to the spatial and factor structure approaches. We consider estimation under strong and weak exogeneity of

SENSIT: a cross-section and design sensitivity and uncertainty analysis code

International Nuclear Information System (INIS)

Gerstl, S.A.W.

1980-01-01

SENSIT computes the sensitivity and uncertainty of a calculated integral response (such as a dose rate) due to input cross sections and their uncertainties. Sensitivity profiles are computed for neutron and gamma-ray reaction cross sections of standard multigroup cross section sets and for secondary energy distributions (SEDs) of multigroup scattering matrices. In the design sensitivity mode, SENSIT computes changes in an integral response due to design changes and gives the appropriate sensitivity coefficients. Cross section uncertainty analyses are performed for three types of input data uncertainties: cross-section covariance matrices for pairs of multigroup reaction cross sections, spectral shape uncertainty parameters for secondary energy distributions (integral SED uncertainties), and covariance matrices for energy-dependent response functions. For all three types of data uncertainties SENSIT computes the resulting variance and estimated standard deviation in an integral response of interest, on the basis of generalized perturbation theory. SENSIT attempts to be more comprehensive than earlier sensitivity analysis codes, such as SWANLAKE

Older adults' beliefs about physician-estimated life expectancy: a cross-sectional survey

Directory of Open Access Journals (Sweden)

Bynum Debra L

2006-02-01

Full Text Available Abstract Background Estimates of life expectancy assist physicians and patients in medical decision-making. The time-delayed benefits for many medical treatments make an older adult's life expectancy estimate particularly important for physicians. The purpose of this study is to assess older adults' beliefs about physician-estimated life expectancy. Methods We performed a mixed qualitative-quantitative cross-sectional study in which 116 healthy adults aged 70+ were recruited from two local retirement communities. We interviewed them regarding their beliefs about physician-estimated life expectancy in the context of a larger study on cancer screening beliefs. Semi-structured interviews of 80 minutes average duration were performed in private locations convenient to participants. Demographic characteristics as well as cancer screening beliefs and beliefs about life expectancy were measured. Two independent researchers reviewed the open-ended responses and recorded the most common themes. The research team resolved disagreements by consensus. Results This article reports the life-expectancy results portion of the larger study. The study group (n = 116 was comprised of healthy, well-educated older adults, with almost a third over 85 years old, and none meeting criteria for dementia. Sixty-four percent (n = 73 felt that their physicians could not correctly estimate their life expectancy. Sixty-six percent (n = 75 wanted their physicians to talk with them about their life expectancy. The themes that emerged from our study indicate that discussions of life expectancy could help older adults plan for the future, maintain open communication with their physicians, and provide them knowledge about their medical conditions. Conclusion The majority of the healthy older adults in this study were open to discussions about life expectancy in the context of discussing cancer screening tests, despite awareness that their physicians' estimates could be inaccurate

Cross sections for atmospheric corrections

International Nuclear Information System (INIS)

Meyer, J.P.; Casse, M.; Westergaard, N.

1975-01-01

A set of cross sections for spallation of relativistic nuclei is proposed based on (i) the best available proton cross sections, (ii) an extrapolation to heavier nuclei of the dependence on the number of nucleons lost of the 'target factor' observed for C 12 and O 16 by Lindstrom et al. (1975), in analogy with Rudstam's formalism, and (iii) on a normalization of all cross sections to the total cross sections for production of fragments with Asub(f) >= 6. The obtained cross sections for peripheral interactions are not inconsistent with simple geometrical considerations. (orig.) [de

Scattering chamber facility for double-differential cross-section

Indian Academy of Sciences (India)

inducedcharged-particle productions is very important for estimating the nuclear heating and radiation damage of a fusion reactor. Only a few experimental data are available even though the nuclear reaction cross-section data of structural materials are ...

Photoneutron and Photonuclear Cross Sections According to Packed cluster Model

International Nuclear Information System (INIS)

El-Mekkawi, L.S.; El-Bakty, O.M.

1998-01-01

Photonuclear gross sections have been estimated for 232 Th, 237 Np, 239 Pu, 233 U, 234 U, 235 U, 238 U in the energy range from threshold up to 20 MeV, by perturbation balance in Packed Cluster. The Packed Cluster (gamma, f) and (gamma, n) cross sections require complete absence of any (gamma,2n) or (gamma,nf) cross sections for 233 U and 234 U as in experiment. It also explains the early (gamma,n) and gamma,nf) reactions in 235 U

Radar cross sections for mesospheric echoes at Jicamarca

Directory of Open Access Journals (Sweden)

G. A. Lehmacher

2009-07-01

Full Text Available Radar cross sections (RCS of mesospheric layers at 50 MHz observed at Jicamarca, Peru, range from 10−18 to 10−16 m−1, three orders of magnitudes smaller than cross sections reported for polar mesospheric winter echoes during solar proton events and six orders of magnitude smaller than polar mesospheric summer echoes. Large RCS are found in thick layers around 70 km that also show wide radar spectra, which is interpreted as turbulent broadening. For typical atmospheric and ionospheric conditions, volume scattering RCS for stationary, homogeneous, isotropic turbulence at 3 m are also in the range 10−18 to 10−16 m−1, in reasonable agreement with measurements. Moreover, theory predicts maximum cross sections around 70 km, also in agreement with observations. Theoretical values are still a matter of order-of-magnitude estimation, since the Bragg scale of 3 m is near or inside the viscous subrange, where the form of the turbulence spectrum is not well known. In addition, steep electron density gradients can increase cross-sections significantly. For thin layers with large RCS and narrow spectra, isotropic turbulence theory fails and scattering or reflection from anisotropic irregularities may gain relevance.

Cross section for inelastic neutron acceleration by 178Hfm2

International Nuclear Information System (INIS)

Karamyan, S.A.; Carroll, J.J.

2009-01-01

The scattering of thermal neutrons from isomeric nuclei may include events in which the outgoing neutrons have increased kinetic energy. This process has been called Inelastic Neutron Acceleration (INNA) and occurs when the final nucleus after emission of the neutron is left in a state with lower energy than that of the isomer. The result, therefore, is an induced depletion of the isomeric population to the ground state. A cascade of several gammas must accompany the neutron emission to release the high angular momentum of the initial isomeric state. INNA was previously observed in a few cases and the associated cross sections were only in modest agreement with theoretical estimates. The most recent measurement of an INNA cross section was σ INNA = (258 ± 58) b for neutron scattering by 177 Lu m . In the present work, an INNA cross section of σ INNA = 152 -36 +51 b was deduced from measurements of the total burn-up of the high-spin, four-quasiparticle isomer 178 Hf m2 during irradiation by thermal neutrons. Statistical estimates for the probability of different reaction channels past neutron absorption were used in the analysis, and the deduced σ INNA is compared to the theoretically predicted cross section

Multitrajectory eikonal cross sections

International Nuclear Information System (INIS)

Turner, R.E.

1983-01-01

With the use of reference and distorted transition operators, a time-correlation-function representation of the inelastic differential cross section has recently been used to obtain distorted eikonal cross sections. These cross sections involve straight-line and reference classical translational trajectories that are unaffected by any internal-state changes which have occurred during the collision. This distorted eikonal theory is now extended to include effects of internal-state changes on the translational motion. In particular, a different classical trajectory is associated with each pair of internal states. Expressions for these inelastic cross sections are obtained in terms of time-ordered cosine and sine memory functions using the Zwanzig-Feshbach projection-operator method. Explicit formulas are obtained in the time-disordered perturbation approximation

FEMA DFIRM Cross Sections

Data.gov (United States)

Minnesota Department of Natural Resources — FEMA Cross Sections are required for any Digital Flood Insurance Rate Map database where cross sections are shown on the Flood Insurance Rate Map (FIRM). Normally...

Use of gamma ray strength functions for predicting the neutron capture cross section of 88Y

International Nuclear Information System (INIS)

Gardner, D.G.; Gardner, M.A.

1977-01-01

The present study indicates that the estimation of the gamma-ray strength function is the approach least subject to error when unmeasured capture cross sections are to be computed. An estimate is given for the 88 γ(n,γ) cross section

Single-meson inclusive cross sections and sequential decay of Reggeons, 2

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Toshihiro

1984-09-01

The single-particle inclusive cross sections of pions and kaons produced from the incident particles in pp and anti pp scattering is investigated under the assumption of the sequential decay mechanism of Reggeons. The many-particle production effect and the initial-decay effect are estimated from experimental data on pion production cross section with small momentum transfer at 100 and 175 GeV/c. Their Feynman-x dependence is in good agreement with the power-law behaviours C(1-X sub(F))/sup 5/ and C(1-X sub(F))/sup 3/. Predictions are given on kaon production cross section.

Fully hadronic ttbar cross section measurement with ATLAS detector

CERN Document Server

Bertella, C; The ATLAS collaboration

2011-01-01

The top quark pair production cross section in the fully hadronic final state is characterized by a six jet topology, two of which could be identified as originating from a b-quark using ATLAS b-tagging algorithms. Compared to other decay channels, this final state presents an advantageous larger branching ratio; on the other hand it suffers from a very large QCD multi-jet background, generally difficult to estimate from Monte Carlo simulation and therefore evaluated using data-driven techniques. It is essential, to efficiently trigger on these fully hadronic ttbar events, to use dedicated triggers. An overview of the analysis for ttbar production cross section measurement in the fully hadronic final state and the state-of-the-art of the b-jet trigger performance estimation are presented in this contribution.

Numerical estimates of multiple reaction corrections in neutron cross-section measurements

International Nuclear Information System (INIS)

Magnusson, G.

1979-04-01

A method to evaluate the effect of secondary neutrons in 14-15 MeV neutron cross-section measurements is presented. The emission spectra of secondary neutrons are calculated by means of the preequilibrium and statistical models. An expression for the collision probability in a homogenous body has been utilized in the calculations. (author)

Consumers' estimation of calorie content at fast food restaurants: cross sectional observational study.

Science.gov (United States)

Block, Jason P; Condon, Suzanne K; Kleinman, Ken; Mullen, Jewel; Linakis, Stephanie; Rifas-Shiman, Sheryl; Gillman, Matthew W

2013-05-23

To investigate estimation of calorie (energy) content of meals from fast food restaurants in adults, adolescents, and school age children. Cross sectional study of repeated visits to fast food restaurant chains. 89 fast food restaurants in four cities in New England, United States: McDonald's, Burger King, Subway, Wendy's, KFC, Dunkin' Donuts. 1877 adults and 330 school age children visiting restaurants at dinnertime (evening meal) in 2010 and 2011; 1178 adolescents visiting restaurants after school or at lunchtime in 2010 and 2011. Estimated calorie content of purchased meals. Among adults, adolescents, and school age children, the mean actual calorie content of meals was 836 calories (SD 465), 756 calories (SD 455), and 733 calories (SD 359), respectively. A calorie is equivalent to 4.18 kJ. Compared with the actual figures, participants underestimated calorie content by means of 175 calories (95% confidence interval 145 to 205), 259 calories (227 to 291), and 175 calories (108 to 242), respectively. In multivariable linear regression models, underestimation of calorie content increased substantially as the actual meal calorie content increased. Adults and adolescents eating at Subway estimated 20% and 25% lower calorie content than McDonald's diners (relative change 0.80, 95% confidence interval 0.66 to 0.96; 0.75, 0.57 to 0.99). People eating at fast food restaurants underestimate the calorie content of meals, especially large meals. Education of consumers through calorie menu labeling and other outreach efforts might reduce the large degree of underestimation.

Calculation of total and ionization cross sections for electron scattering by primary benzene compounds

Science.gov (United States)

Singh, Suvam; Naghma, Rahla; Kaur, Jaspreet; Antony, Bobby

2016-07-01

The total and ionization cross sections for electron scattering by benzene, halobenzenes, toluene, aniline, and phenol are reported over a wide energy domain. The multi-scattering centre spherical complex optical potential method has been employed to find the total elastic and inelastic cross sections. The total ionization cross section is estimated from total inelastic cross section using the complex scattering potential-ionization contribution method. In the present article, the first theoretical calculations for electron impact total and ionization cross section have been performed for most of the targets having numerous practical applications. A reasonable agreement is obtained compared to existing experimental observations for all the targets reported here, especially for the total cross section.

Calculation of total and ionization cross sections for electron scattering by primary benzene compounds

Energy Technology Data Exchange (ETDEWEB)

Singh, Suvam; Naghma, Rahla; Kaur, Jaspreet; Antony, Bobby, E-mail: bka.ism@gmail.com [Atomic and Molecular Physics Lab, Department of Applied Physics, Indian School of Mines, Dhanbad (India)

2016-07-21

The total and ionization cross sections for electron scattering by benzene, halobenzenes, toluene, aniline, and phenol are reported over a wide energy domain. The multi-scattering centre spherical complex optical potential method has been employed to find the total elastic and inelastic cross sections. The total ionization cross section is estimated from total inelastic cross section using the complex scattering potential-ionization contribution method. In the present article, the first theoretical calculations for electron impact total and ionization cross section have been performed for most of the targets having numerous practical applications. A reasonable agreement is obtained compared to existing experimental observations for all the targets reported here, especially for the total cross section.

Estimation of cross sections of hypotetical 8n0, 10He2, 13Li3 nuclei production in the framework of fast fragmentation model

International Nuclear Information System (INIS)

Lozhkin, O.V.; Oplavin, V.S.; Yakovlev, Yu.P.

1983-01-01

The possibilities of search for 8 n 0 , 10 He 2 , 13 Li 3 nuclides in the products of nuclear fragmentation under the action of high energy particles are analysed. Conclusions have been drawn that: available experimental data on determination of the upper boundary of a cross section of 8 n 0 fragments production exclude an existence of this nuclide in the form ''usual'' nuclear system; available experimental estimations of cross sections of 10 He and 13 Li production among fragmentation products are, for the present, insufficient to solve a problem of 13 Li nucleus existence in a bound state but testify on 10 He nucleus nuclear instability; serious model estimations of have functions and nuclide binding energy are necessary

Comparison of integral cross section values of several cross section libraries in the SAND-II format

International Nuclear Information System (INIS)

Zijp, W.L.; Nolthenius, H.J.

1976-09-01

A comparison of some integral cross-section values for several cross-section libraries in the SAND-II format is presented. The integral cross-section values are calculated with the aid of the spectrum functions for a Watt fission spectrum, a 1/E spectrum and a Maxwellian spectrum. The libraries which are considered here are CCC-112B, ENDF/B-IV, DETAN74, LAPENAS and CESNEF. These 5 cross-section libraries used have all the SAND-II format. Discrepancies between cross-sections in the different libraries are indicated but not discussed

Advantages and disadvantages : longitudinal vs. repeated cross-section surveys

Science.gov (United States)

1996-06-20

The benefits of a longitudinal analysis over a repeated cross-sectional study include increased statistical power and the capability to estimate a greater range of conditional probabilities. With the Puget Sound Transportation Panel (PSTP), and any s...

Neutrino-carbon cross section in QRPA models

International Nuclear Information System (INIS)

Samana, Arturo R.; Krmpotic, Francisco; Bertulani, Carlos A.; Paar, Nils

2009-01-01

Full text follows. The ν/ν-bar - 12 C cross sections are calculated in the projected quasiparticle random phase approximation (PQRPA) [1,2] and the relativistic quasiparticle random phase approximation (RQRPA) [3,4]. We compare these cross section as a function of the incident neutrino energy and the number of shells used in the nuclear structure calculation. Additional comparison with other RPA models are performed. A guide to find an upper limit of the incident neutrino energy as a function of the number of shell is implemented. Important consequences on the extrapolation of the cross section to higher neutrino energies is discussed. The formalism obtained in Ref. [1] for the neutrino interaction is extended for antineutrino scattering. This formalism includes the effect of the violation of the Conserved Vector Current by the Coulomb field. It is furthermore simplified by classifying the nuclear matrix elements in natural and unnatural parities. The distribution of cross sections averaged with the Michel spectrum as well as with other estimated fluxes for future experiments are compared for ν e and ν-bar e . Some astrophysical implications are addressed. References [1] F. Krmpotic, A. Mariano and A. Samana, Phys.Lett. B541, 298 (2002). [2] F. Krmpotic, A. Mariano and A. Samana, Phys. Rev. C 71, 044319 (2005). [3] N. Paar, T. Niksic, D. Vretenar, and P. Ring, Phys. Rev. C 69, 054303 (2004). [4] N. Paar, D. Vretenar, T. Marketin and P. Ring, Phys. Rev. C 77, 024608 (2008)

Relativistic photon-Maxwellian electron cross sections

International Nuclear Information System (INIS)

Wienke, B.R.; Lathrop, B.L.; Devaney, J.J.

1986-01-01

Temperature corrected cross sections, complementing the Klein-Nishina set, are developed for astrophysical, plasma, and transport applications. The set is obtained from a nonlinear least squares fit to the exact photon-Maxwellian electron cross sections, using the static formula as the asymptotic basis. Two parameters are sufficient (two decimal places) to fit the exact cross sections over a range of 0-100 keV in electron temperature, and 0-1 MeV in incident photon energy. The fit is made to the total cross sections, yet the parameters predict both total and differential scattering cross sections well. Corresponding differential energy cross sections are less accurate. An extended fit to (just) the total cross sections, over the temperature and energy range 0-5 MeV, is also described. (author)

Estimation of 242Cm neutron cross sections for total file creation

International Nuclear Information System (INIS)

Bakhanovich, L.A.; Klepatskij, A.B.; Maslov, V.M.; Porodzinskij, Yu.V.; Sukhovitskij, E.Sh.

1989-01-01

Description of evaluation of 242 Cm neutron cross sections in 10 -5 eV-20 MeV energy range is given. Due to the lack of experimental data the evaluation is largely based on the application of theoretical models and systematics. The data obtained are compared to evaluations by other authors. 10 refs.; 2 figs.; 2 tabs

Estimation of thermal neutron cross sections from K, U, Th concentrations for rock samples using neural network algorithms

International Nuclear Information System (INIS)

Loskiewicz, J.; Swakon, J.

1992-01-01

In the paper present the results of the use of the neural network algorithms to find a function Σ a =f(K, U, Th,...). The easily measurable parameters (K, U, Th concentrations, lithology) were used to estimate the thermal neutron absorption cross-section Σ a , which is difficult to measure in the borehole conditions. This paper is suggesting a possible solution to the problem. This method may have an important application in the well-logging data treatment. (author). 6 refs, 9 tabs

Integral nucleus-nucleus cross sections

International Nuclear Information System (INIS)

Barashenkov, V.S.; Kumawat, H.

2003-01-01

Expressions approximating the experimental integral cross sections for elastic and inelastic interactions of light and heavy nuclei at the energies up to several GeV/nucleon are presented. The calculated cross sections are inside the corridor of experimental errors or very close to it. Described in detail FORTRAN code and a numerical example of the cross section approximation are also presented

Photon-splitting cross sections

International Nuclear Information System (INIS)

Johannessen, A.M.; Mork, K.J.; Overbo, I.

1980-01-01

The differential cross section for photon splitting (scattering of one photon into two photons) in a Coulomb field, obtained earlier by Shima, has been integrated numerically to yield various differential cross sections. Energy spectra differential with respect to the energy of one of the outgoing photons are presented for several values of the primary photon energy. Selected examples of recoil momentum distributions and some interesting doubly or multiply differential cross sections are also given. Values for the total cross section are obtained essentially for all energies. The screening effect caused by atomic electrons is also taken into account, and is found to be important for high energies, as in e + e - pair production. Comparisons with various approximate results obtained by previous authors mostly show fair agreement. We also discuss the possibilities for experimental detection and find the most promising candidate to be a measurement of both photons, and their energies, at a moderately high energy

Evaluation of the 235U fission cross-section from 100 eV to 20 MeV

International Nuclear Information System (INIS)

Bhat, M.R.

1976-01-01

The evaluation of the 235 U fission cross section from 100 eV to 20 MeV for ENDF/B-V is described. The evaluated average cross sections from 100 eV to 200 keV are given, and it is proposed to include structure in the cross section in this energy region. Above 200 keV, the cross section is given as a smooth curve, and is recommended as a standard. Preliminary error estimates in the cross section are also given

Consumers’ estimation of calorie content at fast food restaurants: cross sectional observational study

Science.gov (United States)

Condon, Suzanne K; Kleinman, Ken; Mullen, Jewel; Linakis, Stephanie; Rifas-Shiman, Sheryl; Gillman, Matthew W

2013-01-01

Objective To investigate estimation of calorie (energy) content of meals from fast food restaurants in adults, adolescents, and school age children. Design Cross sectional study of repeated visits to fast food restaurant chains. Setting 89 fast food restaurants in four cities in New England, United States: McDonald’s, Burger King, Subway, Wendy’s, KFC, Dunkin’ Donuts. Participants 1877 adults and 330 school age children visiting restaurants at dinnertime (evening meal) in 2010 and 2011; 1178 adolescents visiting restaurants after school or at lunchtime in 2010 and 2011. Main outcome measure Estimated calorie content of purchased meals. Results Among adults, adolescents, and school age children, the mean actual calorie content of meals was 836 calories (SD 465), 756 calories (SD 455), and 733 calories (SD 359), respectively. A calorie is equivalent to 4.18 kJ. Compared with the actual figures, participants underestimated calorie content by means of 175 calories (95% confidence interval 145 to 205), 259 calories (227 to 291), and 175 calories (108 to 242), respectively. In multivariable linear regression models, underestimation of calorie content increased substantially as the actual meal calorie content increased. Adults and adolescents eating at Subway estimated 20% and 25% lower calorie content than McDonald’s diners (relative change 0.80, 95% confidence interval 0.66 to 0.96; 0.75, 0.57 to 0.99). Conclusions People eating at fast food restaurants underestimate the calorie content of meals, especially large meals. Education of consumers through calorie menu labeling and other outreach efforts might reduce the large degree of underestimation. PMID:23704170

Gamma-ray production cross sections for MeV neutrons

International Nuclear Information System (INIS)

Kitazawa, Hideo; Harima, Yoshiko; Yamakoshi, Hisao; Sano, Yuji; Kobayashi, Tsuguyuki.

1979-01-01

Gamma-ray production cross section and spectra for 1- to 20-MeV neutrons were theoretically obtained, which were requested for heating calculations, for shielding design calculations, and for material damage estimates. Calculations were carried out for Al, Si, Ca, Fe, Ni, Cu, Nb, Ta, Au, and Pb, using a spin-dependent evaporation model without the parity conservation and including the dipole and quardupole gamma-ray transitions. The results were compared with the experimental data measured in ORNL to confirm the availability of this model in applications. In addition, the effects on the gamma-ray production cross section of the optical potential, level density, yrast level, and radiation width were investigated in detail. The conclusions are: 1) the use of the optical potential which gives the correct total reaction cross section is essential to gamma-ray production calculations, 2) the gamma-ray production cross section is not so sensitive to the choice of level density parameters, 3) the inclusion of yrast levels is necessary in dealing with the competition of the neutron and gamma-ray emissions from highly excited states, and 4) the Brink-Axel type's radiation width is unsuitable to be applied to radiative capture processes. (author)

Cross-sections for semihard interactions in hadronic collisions beyond the leading order of perturbative QCD

International Nuclear Information System (INIS)

Kwiecinski, J.

1986-09-01

Estimate of cross-sections which correspond to semihard interactions such as gluon (mini) jet production is presented. It takes into account recent results concerning gluon distributions in the small x region beyond the leading logQ 2 approximation and rescattering corrections in the hadron-hadron channel. The estimated cross-sections are at very high energies significantly smaller in their magnitude than simple minded integration of the two-jet inclusive cross-section might imply yet they are still expected to constitute a substantial part of σ tot in the TeV energy regime. 18 refs., 2 figs. (author)

Comparison of integral cross section values of several cross section libraries in the SAND-II format

International Nuclear Information System (INIS)

Zijp, W.L.; Nolthenius, H.J.

1978-01-01

A comparison of some integral cross section values for several cross section libraries in the SAND-II format is presented. The integral cross section values are calculated with aid of the spectrum functions for a Watt fission spectrum, a 1/E spectrum and a Maxwellian spectrum. The libraries which are considered here are CCC-112B, ENDF/B-IV, DETAN74, LAPENAS and CESNEF. These 5 cross section libraries used have all the SAND-II format. (author)

Estimation of Fractionally Integrated Panels with Fixed Effects and Cross-Section Dependence

DEFF Research Database (Denmark)

Ergemen, Yunus Emre; Velasco, Carlos

We consider large N, T panel data models with fixed effects, common factors allowing cross-section dependence, and persistent data and shocks, which are assumed fractionally integrated. In a basic setup, the main interest is on the fractional parameter of the idiosyncratic component, which...

Jet inclusive cross sections

International Nuclear Information System (INIS)

Del Duca, V.

1992-11-01

Minijet production in jet inclusive cross sections at hadron colliders, with large rapidity intervals between the tagged jets, is evaluated by using the BFKL pomeron. We describe the jet inclusive cross section for an arbitrary number of tagged jets, and show that it behaves like a system of coupled pomerons

Electron collision cross sections of mercury

International Nuclear Information System (INIS)

Suzuki, Susumu; Kuzuma, Kiyotaka; Itoh, Haruo

2006-01-01

In this paper, we propose a new collision cross section set for mercury which revises the original set summarized by Hayashi in 1989. Hanne reported three excitation collision cross sections (6 3 P 0 , 6 3 P 1 , 6 3 P 2 ) determined from an electron beam experiment in 1988. As a matter for regret, no attentive consideration was given to combining these three excitation cross sections with the cross section set of Hayashi. Therefore we propose a new set where these three excitation cross sections are included. In this study, other two excitation cross sections (6 1 P 1 , 6 3 D 3 ) except for the three excitation collision cross sections (6 3 P 0 , 6 3 P 1 , 6 3 P 2 ) are taken from the original set of Hayashi. The momentum transfer cross section and the ionization collision cross section are also taken from Hayashi. A Monte Carlo Simulation (MCS) technique is applied for evaluating our new cross section set. The present results of the electron drift velocity and the ionization coefficient are compared to experimental values. Agreement is secured in relation to the electron drift velocity for 1.5 Td 2 ) is the reduced electric field, E (V/cm) is the electric field, N (1/cm 3 ) is the number density of mercury atoms at 0degC, 1 Torr, E/N is also equal to 2.828 x 10 -17 E/p 0 from the relation of the ideal gas equation, p 0 (Torr) is gas pressure at 0degC, 1 Torr=1.33322 x 10 -2 N/cm -2 and 10 -17 V/cm 2 is called 1 Td. Thus it is ensured that our new cross section set is reasonable enough to be used up to 100 eV when considering with the electron drift velocity and the ionization coefficient. (author)

Cross-section and panel estimates of peer effects in early adolescent cannabis use: With a little help from my 'friends once removed'.

Science.gov (United States)

Moriarty, John; McVicar, Duncan; Higgins, Kathryn

2016-08-01

Peer effects in adolescent cannabis are difficult to estimate, due in part to the lack of appropriate data on behaviour and social ties. This paper exploits survey data that have many desirable properties and have not previously been used for this purpose. The data set, collected from teenagers in three annual waves from 2002 to 2004 contains longitudinal information about friendship networks within schools (N = 5020). We exploit these data on network structure to estimate peer effects on adolescents from their nominated friends within school using two alternative approaches to identification. First, we present a cross-sectional instrumental variable (IV) estimate of peer effects that exploits network structure at the second degree, i.e. using information on friends of friends who are not themselves ego's friends to instrument for the cannabis use of friends. Second, we present an individual fixed effects estimate of peer effects using the full longitudinal structure of the data. Both innovations allow a greater degree of control for correlated effects than is commonly the case in the substance-use peer effects literature, improving our chances of obtaining estimates of peer effects than can be plausibly interpreted as causal. Both estimates suggest positive peer effects of non-trivial magnitude, although the IV estimate is imprecise. Furthermore, when we specify identical models with behaviour and characteristics of randomly selected school peers in place of friends', we find effectively zero effect from these 'placebo' peers, lending credence to our main estimates. We conclude that cross-sectional data can be used to estimate plausible positive peer effects on cannabis use where network structure information is available and appropriately exploited. Copyright © 2016 Elsevier Ltd. All rights reserved.

Classical pooling of cross-section and time series data

International Nuclear Information System (INIS)

Nuamah, N.N.N.N.

2000-04-01

This paper discusses the classical pooling of cross-section and time series data. The re-expressions of the normal equations of this model are given to indicate the source of the paradox that arises in the estimation of the regression coefficient. (author)

Background-cross-section-dependent subgroup parameters

International Nuclear Information System (INIS)

Yamamoto, Toshihisa

2003-01-01

A new set of subgroup parameters was derived that can reproduce the self-shielded cross section against a wide range of background cross sections. The subgroup parameters are expressed with a rational equation which numerator and denominator are expressed as the expansion series of background cross section, so that the background cross section dependence is exactly taken into account in the parameters. The advantage of the new subgroup parameters is that they can reproduce the self-shielded effect not only by group basis but also by subgroup basis. Then an adaptive method is also proposed which uses fitting procedure to evaluate the background-cross-section-dependence of the parameters. One of the simple fitting formula was able to reproduce the self-shielded subgroup cross section by less than 1% error from the precise evaluation. (author)

Cross-section methodology in SIMMER

International Nuclear Information System (INIS)

Soran, P.D.

1975-11-01

The cross-section methodology incorporated in the SIMMER code is described. Data base for all cross sections is the ENDF/B system with various progressing computer codes to group collapse and modify the group constants which are used in SIMMER. Either infinitely dilute cross sections or the Bondarenko formalism can be used in SIMMER. Presently only a microscopic treatment is considered, but preliminary macroscopic algorithms have been investigated

Cross-section methodology in SIMMER

International Nuclear Information System (INIS)

Soran, P.D.

1976-05-01

The cross-section methodology incorporated in the SIMMER code is described. Data base for all cross sections is the ENDF/B system with various progressing computer codes to group collapse and modify the group constants which are used in SIMMER. Either infinitely dilute cross sections or the Bondarenko formalism can be used in SIMMER. Presently only a microscopic treatment is considered, but preliminary macroscopic algorithms have been investigated

Joint Direction-of-Departure and Direction-of-Arrival Estimation in a UWB MIMO Radar Detecting Targets with Fluctuating Radar Cross Sections

Directory of Open Access Journals (Sweden)

Idnin Pasya

2014-01-01

Full Text Available This paper presents a joint direction-of-departure (DOD and direction-of-arrival (DOA estimation in a multiple-input multiple-output (MIMO radar utilizing ultra wideband (UWB signals in detecting targets with fluctuating radar cross sections (RCS. The UWB MIMO radar utilized a combination of two-way MUSIC and majority decision based on angle histograms of estimated DODs and DOAs at each frequency of the UWB signal. The proposed angle estimation scheme was demonstrated to be effective in detecting targets with fluctuating RCS, compared to conventional spectra averaging method used in subband angle estimations. It was found that a wider bandwidth resulted in improved estimation performance. Numerical simulations along with experimental evaluations in a radio anechoic chamber are presented.

Measurement of aluminum activation cross section and gas production cross section for 0.4 and 3-GeV protons

Directory of Open Access Journals (Sweden)

Meigo Shin-ichiro

2017-01-01

Full Text Available To estimate the lifetime and the radiation dose of the proton beam window used in the spallation neutron source at J-PARC, it is necessary to understand the accuracy of the production cross section of 3-GeV protons. To obtain data on aluminum, the reaction cross section of aluminum was measured at the entrance of the beam dump placed in the 3-GeV proton synchrotron. Owing to the use of well-calibrated current transformers and a well-collimated beam, the present data has good accuracy. After irradiation, the cross sections of Al(p,x7Be, Al(p,x22Na-22 and Al(p,x24Na were obtained by gamma-ray spectroscopy using a Ge detector. It was found that the evaluated data of JENDL/HE-2007 agree well with the current experimental data, whereas intra-nuclear cascade models (Bertini, INCL-4.6, and JAM with the GEM statistical decay model underestimate by about 30% in general. Moreover, gas production, such as T and He, and the cross sections were measured for carbon, which was utilized as the muon production target in J-PARC. The experiment was performed with 3-GeV proton having beam power of 0.5 MW, and the gasses emitted in the process were observed using a quadrupole mass spectrometer in the vacuum line for beam transport to the mercury target. It was found that the JENDL/HE-2007 data agree well with the present experimental data.

Improved activation cross sections for vanadium and titanium

International Nuclear Information System (INIS)

Muir, D.W.; Arthur, E.D.

1983-01-01

Vanadium alloys such as V-20Ti and V-Cr-Ti are attractive candidates for use as structural materials in fusion-reactor blankets. The virtual absence of long-lived activation products in these alloys suggest the possibility of reprocessing on an intermediate time scale. We have employed the modern Hauser-Feshbach nuclear-model code GNASH to calculate cross sections for neutron-activation reactions in 50 V and 51 V, to allow a more accurate assessment of induced radioactivity in vanadium alloys. In addition, cross sections are calculated for the reactions 46 Ti(n,2n) and 45 Ti(n,2n) in order to estimate the production of 44 Ti, a 1.2-MeV gamma-ray source with a half-life of 47 years

Evaluation of Cm-247 neutron cross sections in the resonance region

International Nuclear Information System (INIS)

Martinelli, T.; Menapace, E.; Motta, M.; Vaccari, M.

1980-01-01

The neutron cross sections of Cm-247 are evaluated in the resonance (resolved and unresolved) region up to 10 keV. Average resonance parameters (i.e. spacing D, fission and radiative widths, neutron strength functions) are determined for unresolved region calculations. Moreover for a better comparison with the experimental data, fission cross section is calculated up to 10 MeV. In addition, the average number of neutrons emitted per fission as a function of energy is estimated

Electron-impact cross sections of Ne

International Nuclear Information System (INIS)

Tsurubuchi, S.; Arakawa, K.; Kinokuni, S.; Motohashi, K.

2000-01-01

Electron-impact absolute emission cross sections were measured for the 3p→3s transitions of Ne. Excitation functions of the 3s→2p first resonance lines were measured in the energy range from the threshold to 1000 eV by a polarization-free optical method and relative cross sections were normalized to the absolute values, (41.0±5.4)x10 -19 cm 2 for the 73.6 nm line and (7.1±1.0)x10 -19 cm 2 for the 74.4 nm line, which were determined at 500 eV. The integrated level-excitation cross sections of Suzuki et al for the 1s 2 and 1s 4 levels were combined with the corresponding 3p→3s cascade cross sections obtained in this paper to give absolute emission cross sections for the resonance lines. The level-excitation cross sections of the 1s 2 and 1s 4 states in Paschen notation were determined from the threshold to 1000 eV by subtracting 3p→3s cascade cross sections from the corresponding 3s→2p emission cross sections of the resonance lines. A large cascade contribution is found in the emission cross section of the resonance lines. It is 28.5% for the 73.6 nm line and 49.6% for the 74.4 nm line at 40 eV, and 17.0 and 61.8%, respectively, at 300 eV. (author)

Wind Turbine Radar Cross Section

Directory of Open Access Journals (Sweden)

David Jenn

2012-01-01

Full Text Available The radar cross section (RCS of a wind turbine is a figure of merit for assessing its effect on the performance of electronic systems. In this paper, the fundamental equations for estimating the wind turbine clutter signal in radar and communication systems are presented. Methods of RCS prediction are summarized, citing their advantages and disadvantages. Bistatic and monostatic RCS patterns for two wind turbine configurations, a horizontal axis three-blade design and a vertical axis helical design, are shown. The unique electromagnetic scattering features, the effect of materials, and methods of mitigating wind turbine clutter are also discussed.

Neutron cross sections: Book of curves

International Nuclear Information System (INIS)

McLane, V.; Dunford, C.L.; Rose, P.F.

1988-01-01

Neuton Cross Sections: Book of Curves represents the fourth edition of what was previously known as BNL-325, Neutron Cross Sections, Volume 2, CURVES. Data is presented only for (i.e., intergrated) reaction cross sections (and related fission parameters) as a function of incident-neutron energy for the energy range 0.01 eV to 200 MeV. For the first time, isometric state production cross sections have been included. 11 refs., 4 figs

Evaluated cross section libraries

International Nuclear Information System (INIS)

Maqurno, B.A.

1976-01-01

The dosimetry tape (ENDF/B-IV tape 412) was issued in a general CSEWG distribution, August 1974. The pointwise cross section data file was tested with specified reference spectra. A group averaged cross section data file (620 groups based on tape 412) was tested with the above spectra and the results are presented in this report

Scalar properties of transversely isotropic tuff from images of orthogonal cross sections

International Nuclear Information System (INIS)

Berge, P.A.; Berryman, J.G.; Blair, S.C.; Pena, C.

1997-01-01

Image processing methods have been used very effectively to estimate physical properties of isotropic porous earth materials such as sandstones. Anisotropic materials can also be analyzed in order to estimate their physical properties, but additional care and a larger number of well-chosen images of cross sections are required to obtain correct results. Although low-symmetry anisotropic media present difficulties for two-dimensional image processing methods, geologic materials are often transversely isotropic. Scalar properties of porous materials such as porosity and specific surface area can be determined with only minor changes in the analysis when the medium is transversely isotropic rather than isotropic. For example, in a rock that is transitively isotropic due to thin layers or beds, the overall porosity may be obtained by analyzing images of cross sections taken orthogonal to the bedding planes, whereas cross sections lying within the bedding planes will determine only the local porosity of the bed itself. It is known for translationally invariant anisotropic media that the overall specific surface area can be obtained from radial averages of the two-point correlation function in the full three-dimensional volume. Layered materials are not translationally invariant in the direction of the layering, but we show nevertheless how averages of cross sections may be used to obtain the specific surface area for a transversely isotropic rock. We report values of specific surface area obtained for thin sections of Topopah Spring Tuff from Yucca Mountain, Nevada. This formation is being evaluated as a potential host rock for geologic disposal of nuclear waste. Although the present work has made use of thin sections of tuff for the images, the same methods of analysis could also be used to simplify quantitative analysis of three-dimensional volumes of pore structure data obtained by means of x-ray microtomography or other methods, using only a few representative cross

The Measurement of Neutrino Induced Quasi-Elastic Cross Section In NOMAD

CERN Document Server

Kim, Jae Jun

2010-01-01

NOMAD (Neutrino Oscillation MAgnetic Detector) was a short baseline neutrino experiment conducted at CERN (the European Laboratory for Particle physics) West Area Neutrino Facility (WANF) with a neutrino beam provided by the super proton synchrotron (SPS) accelerator. In this dissertation, we present a measurement of muon-neutrino induced quasi-elastic cross section and its axial-mass off an isoscalar target in the NOMAD detector. The incident neutrino energy in NOMAD experiment spans from 2.5 to 300 GeV. The measurement of cross-section is conducted in two seperate kinematic-based topology, two-track and one-track topologies, where a proton is not properly reconstructed. The QEL cross-section as a function of the incoming neutrino energy is consistent for the two different topologies, and within errors , constant as a function of the neutrino energy. We determine the energy-averaged cross-section. From the shape-comparisons of kinematics of QEL-like events, the parameter of QEL axial mass is estimated. It i...

Nuclear Forensics and Radiochemistry: Cross Sections

Energy Technology Data Exchange (ETDEWEB)

Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-11-08

The neutron activation of components in a nuclear device can provide useful signatures of weapon design or sophistication. This lecture will cover some of the basics of neutron reaction cross sections. Nuclear reactor cross sections will also be presented to illustrate the complexity of convolving neutron energy spectra with nuclear excitation functions to calculate useful effective reactor cross sections. Deficiencies in the nuclear database will be discussed along with tools available at Los Alamos to provide new neutron cross section data.

Total cross section of furfural by electron impact: Experiment and theory

Science.gov (United States)

Traoré Dubuis, A.; Verkhovtsev, A.; Ellis-Gibbings, L.; Krupa, K.; Blanco, F.; Jones, D. B.; Brunger, M. J.; García, G.

2017-08-01

We present experimental total cross sections for electron scattering from furfural in the energy range from 10 to 1000 eV, as measured using a double electrostatic analyzer gas cell electron transmission experiment. These results are compared to theoretical data for furfural, as well as to experimental and theoretical values for the structurally similar molecules furan and tetrahydrofuran. The measured total cross section is in agreement with the theoretical results obtained by means of the independent-atom model with screening corrected additivity rule including interference method. In the region of higher electron energies, from 500 eV to 10 keV, the total electron scattering cross section is also estimated using a semi-empirical model based on the number of electrons and dipole polarizabilities of the molecular targets. Together with the recently measured differential and integral cross sections, and the furfural energy-loss spectra, the present total cross section data nearly complete the data set that is required for numerical simulation of low-energy electron processes in furfural, covering the range of projectile energies from a few electron volts up to 10 keV.

Measurement of fast neutron induced fission cross section of minor-actinide

International Nuclear Information System (INIS)

Hirakawa, Naohiro

2000-06-01

In fuel cycles with recycled actinide, core characteristics are largely influenced by minor actinide (MA: Np, Am, Cm). Accurate nuclear data of MA such as fission cross section are required to estimate the effect of MA with high accuracy. In this study, fast neutron induced fission cross section of MA is measured using Dynamitron accelerator in Tohoku University. The followings were performed in this fiscal year; (1) Research of nuclear data of MA, (2) Sample preparation and sample mass assay, (3) Investigation of neutron sources with the energy of several 10 keV, (4) Preliminary measurement of fission cross section using Dynamitron accelerator. As the result, four 237 Np samples were prepared and the sample mass were measured using alpha-spectrometry with the accuracy of 1.2%. Then, it was confirmed that a neutron source via 7 Li(p,n) 7 Be reaction using a Li-thick target is suitable for measuring fission cross section of MA in the energy region of several 10 keV. Furthermore, it was verified by the preliminary measurement that the measurement of fission cross section of MA is available using a fission chamber and electronics developed in this study. (author)

Total cross section of furfural by electron impact: Experiment and theory.

Science.gov (United States)

Traoré Dubuis, A; Verkhovtsev, A; Ellis-Gibbings, L; Krupa, K; Blanco, F; Jones, D B; Brunger, M J; García, G

2017-08-07

We present experimental total cross sections for electron scattering from furfural in the energy range from 10 to 1000 eV, as measured using a double electrostatic analyzer gas cell electron transmission experiment. These results are compared to theoretical data for furfural, as well as to experimental and theoretical values for the structurally similar molecules furan and tetrahydrofuran. The measured total cross section is in agreement with the theoretical results obtained by means of the independent-atom model with screening corrected additivity rule including interference method. In the region of higher electron energies, from 500 eV to 10 keV, the total electron scattering cross section is also estimated using a semi-empirical model based on the number of electrons and dipole polarizabilities of the molecular targets. Together with the recently measured differential and integral cross sections, and the furfural energy-loss spectra, the present total cross section data nearly complete the data set that is required for numerical simulation of low-energy electron processes in furfural, covering the range of projectile energies from a few electron volts up to 10 keV.

Differential Top Cross-section Measurements

CERN Document Server

Fenton, Michael James; The ATLAS collaboration

2017-01-01

The top quark is the heaviest known fundamental particle. The measurement of the differential top-quark pair production cross-section provides a stringent test of advanced perturbative QCD calculations. The ATLAS collaboration has performed detailed measurements of those differential cross sections at a centre-of-mass energy of 13 TeV. This talk focuses on differential cross-section measurements in the lepton+jets final state, including using boosted top quarks to probe our understanding of top quark production in the TeV regime.

Validation of cross sections for Monte Carlo simulation of the photoelectric effect

CERN Document Server

Han, Min Cheol; Pia, Maria Grazia; Basaglia, Tullio; Batic, Matej; Hoff, Gabriela; Kim, Chan Hyeong; Saracco, Paolo

2016-01-01

Several total and partial photoionization cross section calculations, based on both theoretical and empirical approaches, are quantitatively evaluated with statistical analyses using a large collection of experimental data retrieved from the literature to identify the state of the art for modeling the photoelectric effect in Monte Carlo particle transport. Some of the examined cross section models are available in general purpose Monte Carlo systems, while others have been implemented and subjected to validation tests for the first time to estimate whether they could improve the accuracy of particle transport codes. The validation process identifies Scofield's 1973 non-relativistic calculations, tabulated in the Evaluated Photon Data Library(EPDL), as the one best reproducing experimental measurements of total cross sections. Specialized total cross section models, some of which derive from more recent calculations, do not provide significant improvements. Scofield's non-relativistic calculations are not surp...

Application of sensitivity analysis to a quantitative assessment of neutron cross-section requirements for the TFTR: an interim report

International Nuclear Information System (INIS)

Gerstl, S.A.W.; Dudziak, D.J.; Muir, D.W.

1975-09-01

A computational method to determine cross-section requirements quantitatively is described and applied to the Tokamak Fusion Test Reactor (TFTR). In order to provide a rational basis for the priorities assigned to new cross-section measurements or evaluations, this method includes quantitative estimates of the uncertainty of currently available data, the sensitivity of important nuclear design parameters to selected cross sections, and the accuracy desired in predicting nuclear design parameters. Perturbation theory is used to combine estimated cross-section uncertainties with calculated sensitivities to determine the variance of any nuclear design parameter of interest

Formalism for neutron cross section covariances in the resonance region using kernel approximation

Energy Technology Data Exchange (ETDEWEB)

Oblozinsky, P.; Cho,Y-S.; Matoon,C.M.; Mughabghab,S.F.

2010-04-09

We describe analytical formalism for estimating neutron radiative capture and elastic scattering cross section covariances in the resolved resonance region. We use capture and scattering kernels as the starting point and show how to get average cross sections in broader energy bins, derive analytical expressions for cross section sensitivities, and deduce cross section covariances from the resonance parameter uncertainties in the recently published Atlas of Neutron Resonances. The formalism elucidates the role of resonance parameter correlations which become important if several strong resonances are located in one energy group. Importance of potential scattering uncertainty as well as correlation between potential scattering and resonance scattering is also examined. Practical application of the formalism is illustrated on {sup 55}Mn(n,{gamma}) and {sup 55}Mn(n,el).

Activation cross section data file, (1)

International Nuclear Information System (INIS)

Yamamuro, Nobuhiro; Iijima, Shungo.

1989-09-01

To evaluate the radioisotope productions due to the neutron irradiation in fission of fusion reactors, the data for the activation cross sections ought to be provided. It is planning to file more than 2000 activation cross sections at final. In the current year, the neutron cross sections for 14 elements from Ni to W have been calculated and evaluated in the energy range 10 -5 to 20 MeV. The calculations with a simplified-input nuclear cross section calculation system SINCROS were described, and another method of evaluation which is consistent with the JENDL-3 were also mentioned. The results of cross section calculation are in good agreement with experimental data and they were stored in the file 8, 9 and 10 of ENDF/B format. (author)

The empirical connection between (p,n) cross sections and beta decay transition strengths

International Nuclear Information System (INIS)

Taddeucci, T.N.

1988-01-01

A proportionality is assumed to exist between 0/degree/ (p,n) cross sections and the corresponding beta decay transition strengths. The validity of this assumption is tested by comparison of measured (p,n) cross sections and analogous beta decay strengths. Distorted waves impulse approximation calculations also provide useful estimates of the accuracy of the proportionality relationship. 14 refs., 10 figs

CFRMF spectrum update and application to dosimeter cross-section data testing

International Nuclear Information System (INIS)

Anderl, R.A.; Harker, Y.D.; Millsap, D.A.; Rogers, J.W.; Ryskamp, J.M.

1982-01-01

The Coupled Fast Reactivity Measurements Facility (CFRMF) at the Idaho National Engineering Laboratory (INEL) is a Cross Section Evaluation Working Group (CSEWG) benchmark for data testing of dosimetry, fission-product and actinide cross sections important to fast-reactor technology. In this paper we present the results of our work in updating the CFRMF spectrum characterization and in applying CFRMF integral data to testing ENDF/B-V dosimeter cross sections. Updated characterization of the central neutron spectrum includes the results of neutronics calculations with ENDF/B-V nuclear data, the generation of a fine-group spectrum representation for integral data-testing applications, and a sensitivity and uncertainty analysis which provides a flux-spectrum covariance matrix related to uncertainties and correlations in the nuclear data used in a neutronics calculation. Our application of CFRMF integral data to cross section testing has included both conventional integral testing analyses and least-squares-adjustment analyses with the FERRET code. The conventional integral data-testing analysis, based on C/E ratios, indicates discrepancies outside the estimated integral test uncertainty for the 6 Li(n,He), 10 B(n,He), 47 Ti(n,p), 58 Fe(n,γ), 197 Au(n,γ) and 232 Th(n,γ) cross sections. The integral test uncertainty included contributions from the measured integral data and from the spectrum and cross sections used to obtain the calculated integral data. Within the uncertainty and correlation specifications for the input spectrum and dosimeter cross sections, the least-squares-adjustment analysis indicated a high degree of consistency between the measured integral data and the ENDF/B-V dosimeter cross sections for all reactions except 10 B

Development of improved procedures for evaluation of neutron cross sections for reactor neutron dosimetry

International Nuclear Information System (INIS)

Vonach, H.

1980-06-01

The cross-sections for the four important neutron dosimetry reactions 19 F(n,2n) 18 F, 31 P(n,p) 31 Si, 93 Nb(n,n')sup(93m)Nb and 103 Rh(n,n')sup(103m)Rh were evaluated in the neutron energy range from threshold to 20 MeV. For the 19 F(n,2n) reaction the evaluation could be based entirely on experimental data; for the reactions 31 P(n,p) 31 Si and 103 Rh(n,n')sup(103m)Rh large gaps in the experimental excitation functions and large discrepancies between the existing data made it necessary to supplement the experimental data by cross-section calculations and to give about equal weight to the experimental and calculated cross-sections. For the 93 Nb(n,n')sup(93m)Nb reaction the evaluation had to be based entirely on the theoretically calculated cross-sections. The cross-section calculations were performed using the statistical model of nuclear reactions allowing for precompound processes in the first reaction step and errors of the calculated cross-sections were estimated from their sensitivity to the various input parameters. Cross-section values were evaluated for energy groups between 0.1 MeV and 1 MeV wide, the width depending on both the slope of the excitation functions and the density of the available data. For each evaluated cross-section also an uncertainty (on a 1 sigma confidence level) was derived taking into account the errors given by the experimentalists, the general consistency of the experimental data and the estimated errors of the theoretically calculated cross-sections. In addition relative correlation matrices were derived for each evaluated excitation function describing the correlations between the uncertainties of the cross-sections at different energies. The correlations between the cross-section uncertainties for different reactions were found to be negligible. The results of this evaluation as well as those of Ref. 1 will be combined with the ENDF/B-V dosimetry file into an international neutron dosimetry file by the nuclear data section of

Utilization of cross-section covariance data in FBR core nuclear design and cross-section adjustment

International Nuclear Information System (INIS)

Ishikawa, Makoto

1994-01-01

In the core design of large fast breeder reactors (FBRs), it is essentially important to improve the prediction accuracy of nuclear characteristics from the viewpoint of both reducing cost and insuring reliability of the plant. The cross-section errors, that is, covariance data are one of the most dominant sources for the prediction uncertainty of the core parameters, therefore, quantitative evaluation of covariance data is indispensable for FBR core design. The first objective of the present paper is to introduce how the cross-section covariance data are utilized in the FBR core nuclear design works. The second is to delineate the cross-section adjustment study and its application to an FBR design, because this improved design method markedly enhances the needs and importance of the cross-section covariance data. (author)

HIV incidence in rural South Africa: comparison of estimates from longitudinal surveillance and cross-sectional cBED assay testing.

Directory of Open Access Journals (Sweden)

Till Bärnighausen

Full Text Available The BED IgG-Capture Enzyme Immunoassay (cBED assay, a test of recent HIV infection, has been used to estimate HIV incidence in cross-sectional HIV surveys. However, there has been concern that the assay overestimates HIV incidence to an unknown extent because it falsely classifies some individuals with non-recent HIV infections as recently infected. We used data from a longitudinal HIV surveillance in rural South Africa to measure the fraction of people with non-recent HIV infection who are falsely classified as recently HIV-infected by the cBED assay (the long-term false-positive ratio (FPR and compared cBED assay-based HIV incidence estimates to longitudinally measured HIV incidence.We measured the long-term FPR in individuals with two positive HIV tests (in the HIV surveillance, 2003-2006 more than 306 days apart (sample size n = 1,065. We implemented four different formulae to calculate HIV incidence using cBED assay testing (n = 11,755 and obtained confidence intervals (CIs by directly calculating the central 95(th percentile of incidence values. We observed 4,869 individuals over 7,685 person-years for longitudinal HIV incidence estimation. The long-term FPR was 0.0169 (95% CI 0.0100-0.0266. Using this FPR, the cross-sectional cBED-based HIV incidence estimates (per 100 people per year varied between 3.03 (95% CI 2.44-3.63 and 3.19 (95% CI 2.57-3.82, depending on the incidence formula. Using a long-term FPR of 0.0560 based on previous studies, HIV incidence estimates varied between 0.65 (95% CI 0.00-1.32 and 0.71 (95% CI 0.00-1.43. The longitudinally measured HIV incidence was 3.09 per 100 people per year (95% CI 2.69-3.52, after adjustment to the sex-age distribution of the sample used in cBED assay-based estimation.In a rural community in South Africa with high HIV prevalence, the long-term FPR of the cBED assay is substantially lower than previous estimates. The cBED assay performs well in HIV incidence estimation if the locally

Cross-section calculations for neutron-induced reactions up to 50 MeV

International Nuclear Information System (INIS)

Yamamuro, Nobuhiro.

1996-01-01

In the field of accelerator development, medium-energy reaction cross-section data for structural materials of accelerator and shielding components are required, especially for radiation protection purposes. For a d + Li stripping reaction neutron source used in materials research, neutron reaction cross sections up to 50 MeV are necessary for the design study of neutron irradiation facilities. The current version of SINCROS-II is able to calculate neutron and proton-induced reaction cross sections up to ∼ 50 MeV with some modifications and extensions of the cross-section calculation code. The production of isotopes when structural materials and other materials are bombarded with neutrons or protons is calculated using a revised code in the SINCROS-II system. The parameters used in the cross-section calculations are mainly examined with proton-induced reactions because the experimental data for neutrons above 20 MeV are rare. The status of medium mass nuclide evaluations for aluminum, silicon, chromium, manganese, and copper is presented. These data are useful to estimate the radiation and transmutation of nuclei in the materials

Is the quasielastic pion cross section really bigger than the pion-nucleus reaction cross section

International Nuclear Information System (INIS)

Silbar, R.R.

1979-01-01

It is shown that soft pion charge exchanges may increase the inclusive (π + ,π 0 ') cross section, relative to the total quasielastic (π + ,π + ') cross section, by as much as a factor of two. 4 references

The impact of intermediate structure on the average fission cross sections

International Nuclear Information System (INIS)

Bouland, O.; Lynn, J.E.; Talou, P.

2014-01-01

This paper discusses two common approximations used to calculate average fission cross sections over the compound energy range: the disregard of the W II factor and the Porter-Thomas hypothesis made on the double barrier fission width distribution. By reference to a Monte Carlo-type calculation of formal R-matrix fission widths, this work estimates an overall error ranging from 12% to 20% on the fission cross section in the case of the 239 Pu fissile isotope in the energy domain from 1 to 100 keV with very significant impact on the competing capture cross section. This work is part of a recent and very comprehensive formal R-matrix study over the Pu isotope series and is able to give some hints for significant accuracy improvements in the treatment of the fission channel. (authors)

JENDL gas-production cross section file

International Nuclear Information System (INIS)

Nakagawa, Tsuneo; Narita, Tsutomu

1992-05-01

The JENDL gas-production cross section file was compiled by taking cross-section data from JENDL-3 and by using the ENDF-5 format. The data were given to 23 nuclei or elements in light nuclei and structural materials. Graphs of the cross sections and brief description on their evaluation methods are given in this report. (author)

Doppler broadening of cross sections

International Nuclear Information System (INIS)

Buckler, P.A.C.; Pull, I.C.

1962-12-01

Expressions for temperature dependent cross-sections in terms of resonance parameters are obtained, involving generalisations of the conventional Doppler functions, ψ and φ. Descriptions of Fortran sub-routines, which calculate broadened cross-sections in accordance with the derived formulae, are included. (author)

Fully hadronic ttbar cross section measurement with ATLAS detector

CERN Document Server

Bertella, Claudia

2011-01-01

The top quark pair production cross section in the fully hadronic final state is characterized by a six jet topology, two of which could be identified as originating from a b-quark using ATLAS b-tagging algorithms. Compared to other decay channels, this final state presents an advantageous larger branching ratio; on the other hand it suffers from a very large QCD multi-jet background, generally difficult to estimate from Monte Carlo simulation and therefore evaluated using data-driven techniques. The analysis is performed using 36pb-1 of pp collisions produced at the LHC with a center-of-mass energy of 7 TeV. The observed upper limit is set at 261 pb at 95% confidence level, where the expected Standard Model cross-section for the ttbar process is 165+11-16 pb. In the future, when the LHC luminosity increases, it is essential, to efficiently trigger on these fully hadronic ttbar events, to use dedicated triggers. An overview of the analysis for ttbar production cross section measurement in the fully hadronic f...

The evaluated neutron cross sections and resonance integrals of fission products with Z = 57-62

International Nuclear Information System (INIS)

Fedorova, A.F.; Pisanko, Zh.I.; Novoselov, G.M.

1976-01-01

Neutron cross sections at a neutron velocity of V=2200 m/s, and resonance integrals for fission products with Z=57-71 are estimated. In obtaining the recommended values the results of the neutron cross sections and resonance integrals for elements used as references were normalized in accordance with the latest adjusted values. In the course of estimation, preference was given to the more accurate methods for obtaining the measured values and to the more recent investigations

Cross-sectional anatomy for computed tomography

International Nuclear Information System (INIS)

Farkas, M.L.

1988-01-01

This self-study guide recognizes that evaluation and interpretation of CT-images demands a firm understanding of both cross-sectional anatomy and the principles of computed tomography. The objectives of this book are: to discuss the basic principles of CT, to stress the importance of cross-sectional anatomy to CT through study of selected cardinal transverse sections of head, neck, and trunk, to explain orientation and interpretation of CT-images with the aid of corresponding cross-sectional preparations

Measurement of fast neutron induced fission cross section of minor-actinide

International Nuclear Information System (INIS)

Hirakawa, Naohiro

1997-03-01

In fuel cycles with recycled actinide, core characteristics are largely influenced by minor actinide (MA: Np, Am, Cm). Accurate nuclear data of MA such as fission cross section are required to estimate the effect of MA with high accuracy. In this study, fast neutron induced fission cross section of MA is measured using Dynamitron Accelerator in Tohoku University. The experimental method and the samples, which were developed or introduced during the last year, were improved in this fiscal year: (1) Development of a sealed fission chamber, (2) Intensification of Li neutron target, (3) Improvement of time-resolution of Time-of-Flight (TOF) electronic circuit, (4) Introduction of Np237 samples with large sample mass and (5) Introduction of a U235 sample with high purity. Using these improved tools and samples, the fission cross section ratio of Np237 relative to U235 was measured between 5 to 100 keV, and the fission cross section of Np237 was deduced. On the other hand, samples of Am241 and Am243 were obtained from Japan Atomic Energy Research Institute (JAERI) after investigating fission cross section of two americium isotopes (Am241 and Am 243) which are important for core physics calculation of fast reactors. (author)

Density-dependent expressions for photoionization cross-sections

International Nuclear Information System (INIS)

Sun Weiguo; Ma Xiaoguang; Cheng Yansong

2004-01-01

Alternative expressions for photoionization cross-sections and dielectric influence functions are suggested to study the photoionization cross-sections of atoms in solid system. The basic picture is that the photoionization cross-section of atoms in a real system can be described as the coupling between quantum quantity (QQ) and classical quantity (CQ) parts. The QQ part represents the photoionization cross-sections of an isolated particle, while the CQ part may represent most of the important influence of the macroscopic effects (e.g., the interactions of all surrounding polarized particles, and the dielectric property, etc.) on the photoionization cross-sections. The applications to the barium system show that the number-density-dependent new photoionization formula not only obtains the same cross-sections as those from the first order approximation for ideal gas, but also can generate the cross-sections for solid barium by transforming those of ideal gas of the same species using the dielectric influence function

Density-dependent expressions for photoionization cross-sections

Energy Technology Data Exchange (ETDEWEB)

Sun Weiguo; Ma Xiaoguang; Cheng Yansong

2004-06-07

Alternative expressions for photoionization cross-sections and dielectric influence functions are suggested to study the photoionization cross-sections of atoms in solid system. The basic picture is that the photoionization cross-section of atoms in a real system can be described as the coupling between quantum quantity (QQ) and classical quantity (CQ) parts. The QQ part represents the photoionization cross-sections of an isolated particle, while the CQ part may represent most of the important influence of the macroscopic effects (e.g., the interactions of all surrounding polarized particles, and the dielectric property, etc.) on the photoionization cross-sections. The applications to the barium system show that the number-density-dependent new photoionization formula not only obtains the same cross-sections as those from the first order approximation for ideal gas, but also can generate the cross-sections for solid barium by transforming those of ideal gas of the same species using the dielectric influence function.

Length bias correction in one-day cross-sectional assessments - The nutritionDay study.

Science.gov (United States)

Frantal, Sophie; Pernicka, Elisabeth; Hiesmayr, Michael; Schindler, Karin; Bauer, Peter

2016-04-01

A major problem occurring in cross-sectional studies is sampling bias. Length of hospital stay (LOS) differs strongly between patients and causes a length bias as patients with longer LOS are more likely to be included and are therefore overrepresented in this type of study. To adjust for the length bias higher weights are allocated to patients with shorter LOS. We determined the effect of length-bias adjustment in two independent populations. Length-bias correction is applied to the data of the nutritionDay project, a one-day multinational cross-sectional audit capturing data on disease and nutrition of patients admitted to hospital wards with right-censoring after 30 days follow-up. We applied the weighting method for estimating the distribution function of patient baseline variables based on the method of non-parametric maximum likelihood. Results are validated using data from all patients admitted to the General Hospital of Vienna between 2005 and 2009, where the distribution of LOS can be assumed to be known. Additionally, a simplified calculation scheme for estimating the adjusted distribution function of LOS is demonstrated on a small patient example. The crude median (lower quartile; upper quartile) LOS in the cross-sectional sample was 14 (8; 24) and decreased to 7 (4; 12) when adjusted. Hence, adjustment for length bias in cross-sectional studies is essential to get appropriate estimates. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Total neutron cross section of lead

International Nuclear Information System (INIS)

Kanda, K.; Aizawa, O.

1976-01-01

The total thermal-neutron cross section of natural lead under various physical conditions was measured by the transmission method. It became clear that the total cross section at room temperature previously reported is lower than the present data. The total cross section at 400, 500, and 600 0 C, above the melting point of lead, 327 0 C, was also measured, and the changes in the cross section as a function of temperature were examined, especially near and below the melting point. The data obtained for the randomly oriented polycrystalline state at room temperature were in reasonable agreement with the theoretical values calculated by the THRUSH and UNCLE-TOM codes

Neutron-induced Fission Cross Sections of Am and Cm isotopes (Final Report of Research Contract 14485). Resonance and Fast Neutron Induced Fission Cross Sections of Americium and Curium Nuclides (Third-year Progress Report of Research Contract 14485)

International Nuclear Information System (INIS)

Alekseev, A.A.; Bergman, A.A.; Berlev, A.I.; Koptelov, E.A.; Egorov, A.S.; Samylin, B.F.; Trufanov, A.M.; Fursov, B.I.; Shorin, V.S.

2012-01-01

The neutron induced fission cross sections of Am and Cm isotopes were measured relative to 239 Pu in the neutron energy range from 1 eV to 20 keV at the INR RAS lead slowing down spectrometer LSDS-100. The fission resonance integrals were also estimated using the measured cross section data. The results have been compared with the available experimental and evaluated data. This analysis has shown the present status of the measured fission cross sections and the necessity to revise the evaluated cross sections libraries for the minor actinides. (author)

Market skewness risk and the cross section of stock returns

NARCIS (Netherlands)

Chang, B.; Christoffersen, P.; Jacobs, K.

2013-01-01

The cross section of stock returns has substantial exposure to risk captured by higher moments of market returns. We estimate these moments from daily Standard & Poor's 500 index option data. The resulting time series of factors are genuinely conditional and forward-looking. Stocks with high

Simple, empirical approach to predict neutron capture cross sections from nuclear masses

Science.gov (United States)

Couture, A.; Casten, R. F.; Cakirli, R. B.

2017-12-01

Background: Neutron capture cross sections are essential to understanding the astrophysical s and r processes, the modeling of nuclear reactor design and performance, and for a wide variety of nuclear forensics applications. Often, cross sections are needed for nuclei where experimental measurements are difficult. Enormous effort, over many decades, has gone into attempting to develop sophisticated statistical reaction models to predict these cross sections. Such work has met with some success but is often unable to reproduce measured cross sections to better than 40 % , and has limited predictive power, with predictions from different models rapidly differing by an order of magnitude a few nucleons from the last measurement. Purpose: To develop a new approach to predicting neutron capture cross sections over broad ranges of nuclei that accounts for their values where known and which has reliable predictive power with small uncertainties for many nuclei where they are unknown. Methods: Experimental neutron capture cross sections were compared to empirical mass observables in regions of similar structure. Results: We present an extremely simple method, based solely on empirical mass observables, that correlates neutron capture cross sections in the critical energy range from a few keV to a couple hundred keV. We show that regional cross sections are compactly correlated in medium and heavy mass nuclei with the two-neutron separation energy. These correlations are easily amenable to predict unknown cross sections, often converting the usual extrapolations to more reliable interpolations. It almost always reproduces existing data to within 25 % and estimated uncertainties are below about 40 % up to 10 nucleons beyond known data. Conclusions: Neutron capture cross sections display a surprisingly strong connection to the two-neutron separation energy, a nuclear structure property. The simple, empirical correlations uncovered provide model-independent predictions of

Hadronic cross-sections in two photon processes at a future linear collider

International Nuclear Information System (INIS)

Godbole, Rohini M.; Roeck, Albert de; Grau, Agnes; Pancheri, Giulia

2003-01-01

In this note we address the issue of measurability of the hadronic cross-sections at a future photon collider as well as for the two-photon processes at a future high energy linear e + e - collider. We extend, to higher energy, our previous estimates of the accuracy with which the γ γ cross-section needs to be measured, in order to distinguish between different theoretical models of energy dependence of the total cross-sections. We show that the necessary precision to discriminate among these models is indeed possible at future linear colliders in the Photon Collider option. Further we note that even in the e + e - option a measurement of the hadron production cross-section via γ γ processes, with an accuracy necessary to allow discrimination between different theoretical models, should be possible. We also comment briefly on the implications of these predictions for hadronic backgrounds at the future TeV energy e + e - collider CLIC. (author)

The evaluated neutron cross sections and resonance integrals of fission products with Z=63-71

International Nuclear Information System (INIS)

Fedorova, A.F.; Pisanko, Zh.I.; Novoselov, G.M.

1976-01-01

Neutron cross sections at a neutron velocity of V=2200 m/s, and the resonance integrals for fission products with Z=63-71 are estimated. In obtaining the recommended values the results were normalized of the neutron cross sections and resonance integrals for elements used as references in accordance with the latest adjusted values. In the course of estimation, preference was given to the more accurate measuring methods and the more recent investigations. Scientific publications up to 1975 have been used

Kilo-electron-volt neutron capture cross sections of the krypton isotopes

International Nuclear Information System (INIS)

Walter, G.; Leugers, B.; Kappeler; Bao, Z.Y.; Reffo, G.; Fabbri, F.

1986-01-01

The neutron capture cross sections of the stable krypton isotopes were determined in the energy interval from 4 to 250 keV using a C/sub 6/D/sub 6/-detector system in conjunction with the time-of-flight technique. The energy resolution of the measurement was 4% at 20 keV and 6% at 100 keV, and the experimental uncertainties were typically 6 to 10%. The measurements were complemented by statistical model calculations of all krypton isotopes in the mass range 78 < A < 86 to also obtain reliable cross sections for the unstable nuclei /sup 79,81,85/Kr. These calculations were based on local systematics for all relevant parameters, and the results were estimated to show uncertainties of 20 to 25%. Maxwellian average cross sections were calculated for kT=30 keV

Top quark production cross-section measurements

CERN Document Server

Chen, Ye; The ATLAS collaboration

2017-01-01

Measurements of the inclusive and differential cross-sections for top-quark pair and single top production cross sections in proton-proton collisions with the ATLAS detector at the Large Hadron Collider are presented at center-of-mass energies of 8 TeV and 13 TeV. The inclusive measurements reach high precision and are compared to the best available theoretical calculations. These measurements, including results using boosted tops, probe our understanding of top-pair production in the TeV regime. The results are compared to Monte Carlo generators implementing LO and NLO matrix elements matched with parton showers and NLO QCD calculations. For the t-channel single top measurement, the single top-quark and anti-top-quark total production cross-sections, their ratio, as well as differential cross sections are also presented. A measurement of the production cross-section of a single top quark in association with a W boson, the second largest single-top production mode, is also presented. Finally, measurements of ...

New remarks on KERMA factors and DPA cross section data in ACE files

International Nuclear Information System (INIS)

Konno, Chikara; Sato, Satoshi; Ohta, Masayuki; Kwon, Saerom; Ochiai, Kentaro

2016-01-01

KERMA factors and DPA cross section data are essential for nuclear heating and material damage estimation in fusion reactor designs. Recently we compared KERMA factors and DPA cross section data in the latest official ACE files of JENDL-4.0, ENDF/B-VII.1, JEFF-3.2 and FENDL-3.0 and it was found out that the KERMA factors and DPA cross section data of a lot of nuclei did not always agree among the nuclear data libraries. We investigated the nuclear data libraries and the nuclear data processing code NJOY and specified new reasons for the discrepancies; (1) incorrect nuclear data and NJOY bugs, (2) huge helium production cross section data, (3) gamma production data format in the nuclear data, (4) no detailed secondary particle data (energy–angular distribution data). These problems should be resolved based on this study.

On the infrared sensitivity of the longitudinal cross section in e+e- annihilation

International Nuclear Information System (INIS)

Beneke, M.

1996-09-01

The authors have calculated the contributions proportional to β 0 n α s n+1 to the longitudinal fragmentation function in e + e - annihilation to all orders of perturbation theory. They use this result to estimate higher-order perturbative corrections and nonperturbative corrections to the longitudinal cross section σ L and discuss the prospects of determining α s from σ L . The structure of infrared renormalons in the perturbative expansion suggests that the longitudinal cross section for hadron production with fixed momentum fraction x receives nonperturbative contributions of order 1/(x 2 Q 2 ), whereas the total cross section has a larger, 1/Q correction. This correction arises from very large longitudinal distances and is related to the behavior of the Borel integral for the cross section with fixed x at large values of the Borel parameter

New remarks on KERMA factors and DPA cross section data in ACE files

Energy Technology Data Exchange (ETDEWEB)

Konno, Chikara, E-mail: konno.chikara@jaea.go.jp; Sato, Satoshi; Ohta, Masayuki; Kwon, Saerom; Ochiai, Kentaro

2016-11-01

KERMA factors and DPA cross section data are essential for nuclear heating and material damage estimation in fusion reactor designs. Recently we compared KERMA factors and DPA cross section data in the latest official ACE files of JENDL-4.0, ENDF/B-VII.1, JEFF-3.2 and FENDL-3.0 and it was found out that the KERMA factors and DPA cross section data of a lot of nuclei did not always agree among the nuclear data libraries. We investigated the nuclear data libraries and the nuclear data processing code NJOY and specified new reasons for the discrepancies; (1) incorrect nuclear data and NJOY bugs, (2) huge helium production cross section data, (3) gamma production data format in the nuclear data, (4) no detailed secondary particle data (energy–angular distribution data). These problems should be resolved based on this study.

Creation of problem-dependent Doppler-broadened cross sections in the KENO Monte Carlo code

International Nuclear Information System (INIS)

Hart, Shane W.D.; Celik, Cihangir; Maldonado, G. Ivan; Leal, Luiz

2016-01-01

Highlights: • A quick method of Doppler broadening one- and two-dimensional cross sections has been added to KENO. • The method uses a finite difference method to broaden data to user defined temperatures. • Various problems and benchmarks were run to showcase results. • Results with the Doppler broadened cross sections are closer to benchmark results. - Abstract: This paper introduces a quick method for improving the accuracy of Monte Carlo simulations by generating one- and two-dimensional cross sections at a user-defined temperature before performing transport calculations. A finite difference method is used to Doppler-broaden cross sections to the desired temperature, and unit-base interpolation is done to generate the probability distributions for double differential two-dimensional thermal moderator cross sections at any arbitrarily user-defined temperature. The accuracy of these methods is tested using a variety of contrived problems. In addition, various benchmarks at elevated temperatures are modeled, and results are compared with benchmark results. The problem-dependent cross sections are observed to produce eigenvalue estimates that are closer to the benchmark results than those without the problem-dependent cross sections.

Nuclear Data for Reactor Physics: Cross sections and level densities in the actinide region

Directory of Open Access Journals (Sweden)

Bernstein L.

2010-03-01

Full Text Available Nuclear data in the actinide region are particularly important because they are basis behind all simulations of nuclear reactor core behaviour over both long time scales (fuel depletion and waste production and short time scales (accident scenarios. Nuclear reaction cross sections must be known as precisely as possible so that core reaction rates can be accurately calculated. Although cross section measurements in this region have been widely performed, for certain nuclei, particularly those with short half lives, direct measurements are either very difficult or impossible and thus reactor simulations must rely on theoretical calculations or extrapolations from neighbouring nuclei. The greatest uncertainty in theoretical cross section calculations comes from the lack of knowledge of level densities, for which predicted values can often be incorrect by a factor of two or more. Therefore there is a strong case for a systematic experimental study of level densities in the actinide region for the purpose of a providing a stringent test of theoretical cross section calculations for nuclei where experimental cross section data are available and b for providing better estimations of cross sections for nuclei in which no cross section data are available.

Optimal cross-sectional sampling for river modelling with bridges: An information theory-based method

Energy Technology Data Exchange (ETDEWEB)

Ridolfi, E.; Napolitano, F., E-mail: francesco.napolitano@uniroma1.it [Sapienza Università di Roma, Dipartimento di Ingegneria Civile, Edile e Ambientale (Italy); Alfonso, L. [Hydroinformatics Chair Group, UNESCO-IHE, Delft (Netherlands); Di Baldassarre, G. [Department of Earth Sciences, Program for Air, Water and Landscape Sciences, Uppsala University (Sweden)

2016-06-08

The description of river topography has a crucial role in accurate one-dimensional (1D) hydraulic modelling. Specifically, cross-sectional data define the riverbed elevation, the flood-prone area, and thus, the hydraulic behavior of the river. Here, the problem of the optimal cross-sectional spacing is solved through an information theory-based concept. The optimal subset of locations is the one with the maximum information content and the minimum amount of redundancy. The original contribution is the introduction of a methodology to sample river cross sections in the presence of bridges. The approach is tested on the Grosseto River (IT) and is compared to existing guidelines. The results show that the information theory-based approach can support traditional methods to estimate rivers’ cross-sectional spacing.

Optimal cross-sectional sampling for river modelling with bridges: An information theory-based method

International Nuclear Information System (INIS)

Ridolfi, E.; Napolitano, F.; Alfonso, L.; Di Baldassarre, G.

2016-01-01

The description of river topography has a crucial role in accurate one-dimensional (1D) hydraulic modelling. Specifically, cross-sectional data define the riverbed elevation, the flood-prone area, and thus, the hydraulic behavior of the river. Here, the problem of the optimal cross-sectional spacing is solved through an information theory-based concept. The optimal subset of locations is the one with the maximum information content and the minimum amount of redundancy. The original contribution is the introduction of a methodology to sample river cross sections in the presence of bridges. The approach is tested on the Grosseto River (IT) and is compared to existing guidelines. The results show that the information theory-based approach can support traditional methods to estimate rivers’ cross-sectional spacing.

Statistical Model Analysis of (n, α Cross Sections for 4.0-6.5 MeV Neutrons

Directory of Open Access Journals (Sweden)

Khuukhenkhuu G.

2016-01-01

Full Text Available The statistical model based on the Weisskopf-Ewing theory and constant nuclear temperature approximation is used for systematical analysis of the 4.0-6.5 MeV neutron induced (n, α reaction cross sections. The α-clusterization effect was considered in the (n, α cross sections. A certain dependence of the (n, α cross sections on the relative neutron excess parameter of the target nuclei was observed. The systematic regularity of the (n, α cross sections behaviour is useful to estimate the same reaction cross sections for unstable isotopes. The results of our analysis can be used for nuclear astrophysical calculations such as helium burning and possible branching in the s-process.

Improved calculation of displacements per atom cross section in solids by gamma and electron irradiation

Energy Technology Data Exchange (ETDEWEB)

Piñera, Ibrahin, E-mail: ipinera@ceaden.edu.cu [Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear, CEADEN, 30 St. 502, Playa 11300, Havana (Cuba); Cruz, Carlos M.; Leyva, Antonio; Abreu, Yamiel; Cabal, Ana E. [Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear, CEADEN, 30 St. 502, Playa 11300, Havana (Cuba); Espen, Piet Van; Remortel, Nick Van [University of Antwerp, CGB, Groenenborgerlaan 171, 2020 Antwerpen (Belgium)

2014-11-15

Highlights: • We present a calculation procedure for dpa cross section in solids under irradiation. • Improvement about 10–90% for the gamma irradiation induced dpa cross section. • Improvement about 5–50% for the electron irradiation induced dpa cross section. • More precise results (20–70%) for thin samples irradiated with electrons. - Abstract: Several authors had estimated the displacements per atom cross sections under different approximations and models, including most of the main gamma- and electron-material interaction processes. These previous works used numerical approximation formulas which are applicable for limited energy ranges. We proposed the Monte Carlo assisted Classical Method (MCCM), which relates the established theories about atom displacements to the electron and positron secondary fluence distributions calculated from the Monte Carlo simulation. In this study the MCCM procedure is adapted in order to estimate the displacements per atom cross sections for gamma and electron irradiation. The results obtained through this procedure are compared with previous theoretical calculations. An improvement in about 10–90% for the gamma irradiation induced dpa cross section is observed in our results on regard to the previous evaluations for the studied incident energies. On the other hand, the dpa cross section values produced by irradiation with electrons are improved by our calculations in about 5–50% when compared with the theoretical approximations. When thin samples are irradiated with electrons, more precise results are obtained through the MCCM (in about 20–70%) with respect to the previous studies.

Differences between LASL- and ANL-processed cross sections

International Nuclear Information System (INIS)

Kidman, R.B.; MacFarlane, R.E.; Becker, M.

1978-03-01

As part of the Los Alamos Scientific Laboratory (LASL) cross-section processing development, LASL cross sections and results from MINX/1DX system are compared to the Argonne National Laboratory cross sections and results from the ETOE-2/MC 2 -2 system for a simple reactor problem. Exact perturbation theory is used to establish the eigenvalue effect of every isotope group cross-section difference. Cross sections, cross-section differences, and their eigenvalue effects are clearly and conveniently displayed and compared on a group-by-group basis

Prospectively measured 10-year changes in health-related quality of life and comparison with cross-sectional estimates in a population-based cohort of adult women and men.

Science.gov (United States)

Hopman, Wilma M; Berger, Claudie; Joseph, Lawrence; Zhou, Wei; Prior, Jerilynn C; Towheed, Tanveer; Anastassiades, Tassos; Adachi, Jonathan D; Hanley, David A; Papadimitropoulos, Emmanuel A; Kirkland, Susan; Kaiser, Stephanie M; Josse, Robert G; Goltzman, David

2014-12-01

To prospectively assess changes in health-related quality of life (HRQOL) over 10 years, by age and sex, and to compare measured within-person change to estimates of change based on cross-sectional data. Participants in the Canadian Multicentre Osteoporosis Study completed the 36-item short form (SF-36) in 1995/1997 and 2005/2007. Mean within-person changes for domain and summary components were calculated for men and women separately, stratified by 10-year age groups. Projected changes based on published age- and sex-stratified cross-sectional data were also calculated. Mean differences between the two methods were then estimated, along with the 95 % credible intervals of the differences. Data were available for 5,569/9,423 (59.1 %) of the original cohort. Prospectively collected 10-year changes suggested that the four physically oriented domains declined in all but the youngest group of men and women, with declines in the elderly men exceeding 25 points. The four mentally oriented domains tended to improve over time, only showing substantial declines in vitality and role emotional in older women, and all four domains in older men. Cross-sectional estimates identified a similar pattern of change but with a smaller magnitude, particularly in men. Correspondence between the two methods was generally high. Changes in HRQOL may be minimal over much of the life span, but physically oriented HRQOL can decline substantially after middle age. Although clinically relevant declines were more evident in prospectively collected data, differences in 10-year age increments of cross-sectional data may be a reasonable proxy for longitudinal changes, at least in those under 65 years of age. Results provide additional insight into the natural progression of HRQOL in the general population.

Upsilon production cross section in pp collisions at $\\sqrt{s}$ = 7 TeV

CERN Document Server

Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hammer, Josef; Haensel, Stephan; Hartl, Christian; Hoch, Michael; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kasieczka, Gregor; Kiesenhofer, Wolfgang; Krammer, Manfred; Liko, Dietrich; Mikulec, Ivan; Pernicka, Manfred; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Teischinger, Florian; Waltenberger, Wolfgang; Walzel, Gerhard; Widl, Edmund; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Benucci, Leonardo; Ceard, Ludivine; Cerny, Karel; De Wolf, Eddi A.; Janssen, Xavier; Maes, Thomas; Mucibello, Luca; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Selvaggi, Michele; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Adler, Volker; Beauceron, Stephanie; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Devroede, Olivier; Gonzalez Suarez, Rebeca; Kalogeropoulos, Alexis; Maes, Joris; Maes, Michael; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Charaf, Otman; Clerbaux, Barbara; De Lentdecker, Gilles; Dero, Vincent; Gay, Arnaud; Hammad, Gregory Habib; Hreus, Tomas; Marage, Pierre Edouard; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wickens, John; Costantini, Silvia; Grunewald, Martin; Klein, Benjamin; Marinov, Andrey; Mccartin, Joseph; Ryckbosch, Dirk; Thyssen, Filip; Tytgat, Michael; Vanelderen, Lukas; Verwilligen, Piet; Walsh, Sinead; Zaganidis, Nicolas; Basegmez, Suzan; Bruno, Giacomo; Caudron, Julien; De Favereau De Jeneret, Jerome; Delaere, Christophe; Demin, Pavel; Favart, Denis; Giammanco, Andrea; Grégoire, Ghislain; Hollar, Jonathan; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Ovyn, Severine; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Quertenmont, Loic; Schul, Nicolas; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Alves, Gilvan; De Jesus Damiao, Dilson; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Carvalho, Wagner; Melo Da Costa, Eliza; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Mundim, Luiz; Nogima, Helio; Oguri, Vitor; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Silva Do Amaral, Sheila Mara; Sznajder, Andre; De Almeida Dias, Flavia; Ferreira Dias, Marco Andre; Tomei, Thiago; De Moraes Gregores, Eduardo; Da Cunha Marinho, Franciole; Novaes, Sergio F.; Padula, Sandra; Darmenov, Nikolay; Dimitrov, Lubomir; Genchev, Vladimir; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Tcholakov, Vanio; Trayanov, Rumen; Vankov, Ivan; Dyulendarova, Milena; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Marinova, Evelina; Mateev, Matey; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Wang, Jian; Wang, Jian; Wang, Xianyou; Wang, Zheng; Xu, Ming; Yang, Min; Zang, Jingjing; Zhang, Zhen; Ban, Yong; Guo, Shuang; Li, Wenbo; Mao, Yajun; Qian, Si-Jin; Teng, Haiyun; Zhang, Linlin; Zhu, Bo; Cabrera, Andrés; Gomez Moreno, Bernardo; Ocampo Rios, Alberto Andres; Osorio Oliveros, Andres Felipe; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Lelas, Karlo; Plestina, Roko; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Dzelalija, Mile; Brigljevic, Vuko; Duric, Senka; Kadija, Kreso; Morovic, Srecko; Attikis, Alexandros; Galanti, Mario; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A.; Rykaczewski, Hans; Assran, Yasser; Mahmoud, Mohammed; Hektor, Andi; Kadastik, Mario; Kannike, Kristjan; Müntel, Mait; Raidal, Martti; Rebane, Liis; Azzolini, Virginia; Eerola, Paula; Czellar, Sandor; Härkönen, Jaakko; Heikkinen, Mika Aatos; Karimäki, Veikko; Kinnunen, Ritva; Klem, Jukka; Kortelainen, Matti J.; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Ungaro, Donatella; Wendland, Lauri; Banzuzi, Kukka; Korpela, Arja; Tuuva, Tuure; Sillou, Daniel; Besancon, Marc; Choudhury, Somnath; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Ferri, Federico; Ganjour, Serguei; Gentit, François-Xavier; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Marionneau, Matthieu; Millischer, Laurent; Rander, John; Rosowsky, André; Shreyber, Irina; Titov, Maksym; Verrecchia, Patrice; Baffioni, Stephanie; Beaudette, Florian; Bianchini, Lorenzo; Bluj, Michal; Broutin, Clementine; Busson, Philippe; Charlot, Claude; Dahms, Torsten; Dobrzynski, Ludwik; Granier de Cassagnac, Raphael; Haguenauer, Maurice; Miné, Philippe; Mironov, Camelia; Ochando, Christophe; Paganini, Pascal; Sabes, David; Salerno, Roberto; Sirois, Yves; Thiebaux, Christophe; Wyslouch, Bolek; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Besson, Auguste; Bloch, Daniel; Bodin, David; Brom, Jean-Marie; Cardaci, Marco; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Drouhin, Frédéric; Ferro, Cristina; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Greder, Sebastien; Juillot, Pierre; Karim, Mehdi; Le Bihan, Anne-Catherine; Mikami, Yoshinari; Van Hove, Pierre; Fassi, Farida; Mercier, Damien; Baty, Clement; Beaupere, Nicolas; Bedjidian, Marc; Bondu, Olivier; Boudoul, Gaelle; Boumediene, Djamel; Brun, Hugues; Chanon, Nicolas; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Falkiewicz, Anna; Fay, Jean; Gascon, Susan; Ille, Bernard; Kurca, Tibor; Le Grand, Thomas; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Sordini, Viola; Tosi, Silvano; Tschudi, Yohann; Verdier, Patrice; Xiao, Hong; Roinishvili, Vladimir; Anagnostou, Georgios; Edelhoff, Matthias; Feld, Lutz; Heracleous, Natalie; Hindrichs, Otto; Jussen, Ruediger; Klein, Katja; Merz, Jennifer; Mohr, Niklas; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Sprenger, Daniel; Weber, Hendrik; Weber, Martin; Wittmer, Bruno; Ata, Metin; Bender, Walter; Erdmann, Martin; Frangenheim, Jens; Hebbeker, Thomas; Hinzmann, Andreas; Hoepfner, Kerstin; Hof, Carsten; Klimkovich, Tatsiana; Klingebiel, Dennis; Kreuzer, Peter; Lanske, Dankfried; Magass, Carsten; Masetti, Gianni; Merschmeyer, Markus; Meyer, Arnd; Papacz, Paul; Pieta, Holger; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Steggemann, Jan; Teyssier, Daniel; Bontenackels, Michael; Davids, Martina; Duda, Markus; Flügge, Günter; Geenen, Heiko; Giffels, Manuel; Haj Ahmad, Wael; Heydhausen, Dirk; Kress, Thomas; Kuessel, Yvonne; Linn, Alexander; Nowack, Andreas; Perchalla, Lars; Pooth, Oliver; Rennefeld, Jörg; Sauerland, Philip; Stahl, Achim; Thomas, Maarten; Tornier, Daiske; Zoeller, Marc Henning; Aldaya Martin, Maria; Behrenhoff, Wolf; Behrens, Ulf; Bergholz, Matthias; Borras, Kerstin; Cakir, Altan; Campbell, Alan; Castro, Elena; Dammann, Dirk; Eckerlin, Guenter; Eckstein, Doris; Flossdorf, Alexander; Flucke, Gero; Geiser, Achim; Glushkov, Ivan; Hauk, Johannes; Jung, Hannes; Kasemann, Matthias; Katkov, Igor; Katsas, Panagiotis; Kleinwort, Claus; Kluge, Hannelies; Knutsson, Albert; Krücker, Dirk; Kuznetsova, Ekaterina; Lange, Wolfgang; Lohmann, Wolfgang; Mankel, Rainer; Marienfeld, Markus; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mnich, Joachim; Mussgiller, Andreas; Olzem, Jan; Parenti, Andrea; Raspereza, Alexei; Raval, Amita; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Sen, Niladri; Stein, Matthias; Tomaszewska, Justyna; Volyanskyy, Dmytro; Walsh, Roberval; Wissing, Christoph; Autermann, Christian; Bobrovskyi, Sergei; Draeger, Jula; Enderle, Holger; Gebbert, Ulla; Kaschube, Kolja; Kaussen, Gordon; Klanner, Robert; Lange, Jörn; Mura, Benedikt; Naumann-Emme, Sebastian; Nowak, Friederike; Pietsch, Niklas; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schröder, Matthias; Schum, Torben; Schwandt, Joern; Srivastava, Ajay Kumar; Stadie, Hartmut; Steinbrück, Georg; Thomsen, Jan; Wolf, Roger; Barth, Christian; Bauer, Julia; Buege, Volker; Chwalek, Thorsten; De Boer, Wim; Dierlamm, Alexander; Dirkes, Guido; Feindt, Michael; Gruschke, Jasmin; Hackstein, Christoph; Hartmann, Frank; Heindl, Stefan Michael; Heinrich, Michael; Held, Hauke; Hoffmann, Karl-Heinz; Honc, Simon; Kuhr, Thomas; Martschei, Daniel; Mueller, Steffen; Müller, Thomas; Niegel, Martin; Oberst, Oliver; Oehler, Andreas; Ott, Jochen; Peiffer, Thomas; Piparo, Danilo; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Renz, Manuel; Saout, Christophe; Scheurer, Armin; Schieferdecker, Philipp; Schilling, Frank-Peter; Schott, Gregory; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Troendle, Daniel; Wagner-Kuhr, Jeannine; Zeise, Manuel; Zhukov, Valery; Ziebarth, Eva Barbara; Daskalakis, Georgios; Geralis, Theodoros; Kesisoglou, Stilianos; Kyriakis, Aristotelis; Loukas, Demetrios; Manolakos, Ioannis; Markou, Athanasios; Markou, Christos; Mavrommatis, Charalampos; Petrakou, Eleni; Gouskos, Loukas; Mertzimekis, Theodoros; Panagiotou, Apostolos; Evangelou, Ioannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Patras, Vaios; Triantis, Frixos A.; Aranyi, Attila; Bencze, Gyorgy; Boldizsar, Laszlo; Debreczeni, Gergely; Hajdu, Csaba; Horvath, Dezso; Kapusi, Anita; Krajczar, Krisztian; Laszlo, Andras; Sikler, Ferenc; Vesztergombi, Gyorgy; Beni, Noemi; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Veszpremi, Viktor; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Dhingra, Nitish; Jindal, Monika; Kaur, Manjit; Kohli, Jatinder Mohan; Mehta, Manuk Zubin; Nishu, Nishu; Saini, Lovedeep Kaur; Sharma, Archana; Singh, Anil; Singh, Jas Bir; Singh, Supreet Pal; Ahuja, Sudha; Bhattacharya, Satyaki; Choudhary, Brajesh C.; Gupta, Pooja; Jain, Sandhya; Jain, Shilpi; Kumar, Ashok; Shivpuri, Ram Krishen; Choudhury, Rajani Kant; Dutta, Dipanwita; Kailas, Swaminathan; Kataria, Sushil Kumar; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Suggisetti, Praveenkumar; Aziz, Tariq; Guchait, Monoranjan; Gurtu, Atul; Maity, Manas; Majumder, Devdatta; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Saha, Anirban; Sudhakar, Katta; Wickramage, Nadeesha; Banerjee, Sudeshna; Dugad, Shashikant; Mondal, Naba Kumar; Arfaei, Hessamaddin; Bakhshiansohi, Hamed; Etesami, Seyed Mohsen; Fahim, Ali; Hashemi, Majid; Jafari, Abideh; Khakzad, Mohsen; Mohammadi, Abdollah; Mohammadi Najafabadi, Mojtaba; Paktinat Mehdiabadi, Saeid; Safarzadeh, Batool; Zeinali, Maryam; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Dimitrov, Anton; Fiore, Luigi; Iaselli, Giuseppe; Lusito, Letizia; Maggi, Giorgio; Maggi, Marcello; Manna, Norman; Marangelli, Bartolomeo; My, Salvatore; Nuzzo, Salvatore; Pacifico, Nicola; Pierro, Giuseppe Antonio; Pompili, Alexis; Pugliese, Gabriella; Romano, Francesco; Roselli, Giuseppe; Selvaggi, Giovanna; Silvestris, Lucia; Trentadue, Raffaello; Tupputi, Salvatore; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Giunta, Marina; Grandi, Claudio; Marcellini, Stefano; Meneghelli, Marco; Montanari, Alessandro; Navarria, Francesco; Odorici, Fabrizio; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gianni; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Frosali, Simone; Gallo, Elisabetta; Genta, Chiara; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Colafranceschi, Stefano; Fabbri, Franco; Piccolo, Davide; Fabbricatore, Pasquale; Musenich, Riccardo; Benaglia, Andrea; De Guio, Federico; Di Matteo, Leonardo; Ghezzi, Alessio; Malberti, Martina; Malvezzi, Sandra; Martelli, Arabella; Massironi, Andrea; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Sala, Silvano; Tabarelli de Fatis, Tommaso; Tancini, Valentina; Buontempo, Salvatore; Carrillo Montoya, Camilo Andres; Cimmino, Anna; De Cosa, Annapaola; De Gruttola, Michele; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Merola, Mario; Noli, Pasquale; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bellan, Paolo; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; De Mattia, Marco; Dorigo, Tommaso; Dosselli, Umberto; Fanzago, Federica; Gasparini, Fabrizio; Gasparini, Ugo; Giubilato, Piero; Gresele, Ambra; Lacaprara, Stefano; Lazzizzera, Ignazio; Margoni, Martino; Mazzucato, Mirco; Meneguzzo, Anna Teresa; Nespolo, Massimo; Perrozzi, Luca; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Vanini, Sara; Zotto, Pierluigi; Zumerle, Gianni; Baesso, Paolo; Berzano, Umberto; Riccardi, Cristina; Torre, Paola; Vitulo, Paolo; Viviani, Claudio; Biasini, Maurizio; Bilei, Gian Mario; Caponeri, Benedetta; Fanò, Livio; Lariccia, Paolo; Lucaroni, Andrea; Mantovani, Giancarlo; Menichelli, Mauro; Nappi, Aniello; Santocchia, Attilio; Servoli, Leonello; Taroni, Silvia; Valdata, Marisa; Volpe, Roberta; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; D'Agnolo, Raffaele Tito; Dell'Orso, Roberto; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Kraan, Aafke; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Palmonari, Francesco; Sarkar, Subir; Serban, Alin Titus; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Del Re, Daniele; Di Marco, Emanuele; Diemoz, Marcella; Franci, Daniele; Grassi, Marco; Longo, Egidio; Organtini, Giovanni; Palma, Alessandro; Pandolfi, Francesco; Paramatti, Riccardo; Rahatlou, Shahram; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Biino, Cristina; Botta, Cristina; Cartiglia, Nicolo; Castello, Roberto; Costa, Marco; Demaria, Natale; Graziano, Alberto; Mariotti, Chiara; Marone, Matteo; Maselli, Silvia; Migliore, Ernesto; Mila, Giorgia; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Pastrone, Nadia; Pelliccioni, Mario; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Sola, Valentina; Solano, Ada; Staiano, Amedeo; Trocino, Daniele; Vilela Pereira, Antonio; Ambroglini, Filippo; Belforte, Stefano; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; Montanino, Damiana; Penzo, Aldo; Heo, Seong Gu; Chang, Sunghyun; Chung, Jin Hyuk; Kim, Dong Hee; Kim, Gui Nyun; Kim, Ji Eun; Kong, Dae Jung; Park, Hyangkyu; Son, Dohhee; Son, Dong-Chul; Kim, Jaeho; Kim, Jae Yool; Song, Sanghyeon; Choi, Suyong; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Ji Hyun; Kim, Tae Jeong; Lee, Kyong Sei; Moon, Dong Ho; Park, Sung Keun; Rhee, Han-Bum; Seo, Eunsung; Shin, Seungsu; Sim, Kwang Souk; Choi, Minkyoo; Kang, Seokon; Kim, Hyunyong; Park, Chawon; Park, Inkyu; Park, Sangnam; Ryu, Geonmo; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Lee, Jongseok; Lee, Sungeun; Seo, Hyunkwan; Yu, Intae; Bilinskas, Mykolas Jurgis; Grigelionis, Ignas; Janulis, Mindaugas; Martisiute, Dalia; Petrov, Pavel; Sabonis, Tomas; Castilla Valdez, Heriberto; De La Cruz Burelo, Eduard; Lopez-Fernandez, Ricardo; Sánchez Hernández, Alberto; Villasenor-Cendejas, Luis Manuel; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Reyes-Santos, Marco A.; Allfrey, Philip; Krofcheck, David; Butler, Philip H.; Doesburg, Robert; Silverwood, Hamish; Ahmad, Muhammad; Ahmed, Ijaz; Asghar, Muhammad Irfan; Hoorani, Hafeez R.; Khan, Wajid Ali; Khurshid, Taimoor; Qazi, Shamona; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Frueboes, Tomasz; Gokieli, Ryszard; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Wrochna, Grzegorz; Zalewski, Piotr; Almeida, Nuno; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Sá Martins, Pedro; Musella, Pasquale; Nayak, Aruna; Ribeiro, Pedro Quinaz; Seixas, Joao; Silva, Pedro; Varela, Joao; Wöhri, Hermine Katharina; Belotelov, Ivan; Bunin, Pavel; Finger, Miroslav; Finger Jr., Michael; Golutvin, Igor; Kamenev, Alexey; Karjavin, Vladimir; Kozlov, Guennady; Lanev, Alexander; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Smirnov, Vitaly; Volodko, Anton; Zarubin, Anatoli; Bondar, Nikolai; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Andreev, Yuri; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Matveev, Viktor; Pashenkov, Anatoli; Toropin, Alexander; Troitsky, Sergey; Epshteyn, Vladimir; Gavrilov, Vladimir; Kaftanov, Vitali; Kossov, Mikhail; Krokhotin, Andrey; Lychkovskaya, Natalia; Safronov, Grigory; Semenov, Sergey; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Kodolova, Olga; Lokhtin, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Sarycheva, Ludmila; Savrin, Viktor; Snigirev, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Rusakov, Sergey V.; Vinogradov, Alexey; Azhgirey, Igor; Bitioukov, Sergei; Grishin, Viatcheslav; Kachanov, Vassili; Konstantinov, Dmitri; Korablev, Andrey; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Slabospitsky, Sergey; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Djordjevic, Milos; Krpic, Dragomir; Milosevic, Jovan; Aguilar-Benitez, Manuel; Alcaraz Maestre, Juan; Arce, Pedro; Battilana, Carlo; Calvo, Enrique; Cepeda, Maria; Cerrada, Marcos; Colino, Nicanor; De La Cruz, Begona; Diez Pardos, Carmen; Domínguez Vázquez, Daniel; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Ferrando, Antonio; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M.; Josa, Maria Isabel; Merino, Gonzalo; Puerta Pelayo, Jesus; Redondo, Ignacio; Romero, Luciano; Santaolalla, Javier; Willmott, Carlos; Albajar, Carmen; Codispoti, Giuseppe; de Trocóniz, Jorge F; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Lloret Iglesias, Lara; Vizan Garcia, Jesus Manuel; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Chamizo Llatas, Maria; Chuang, Shan-Huei; Duarte Campderros, Jordi; Felcini, Marta; Fernandez, Marcos; Gomez, Gervasio; Gonzalez Sanchez, Javier; Jorda, Clara; Lobelle Pardo, Patricia; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Ruiz Jimeno, Alberto; Scodellaro, Luca; Sobron Sanudo, Mar; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Baillon, Paul; Ball, Austin; Barney, David; Bell, Alan James; Benedetti, Daniele; Bernet, Colin; Bialas, Wojciech; Bloch, Philippe; Bocci, Andrea; Bolognesi, Sara; Breuker, Horst; Brona, Grzegorz; Bunkowski, Karol; Camporesi, Tiziano; Cano, Eric; Cerminara, Gianluca; Christiansen, Tim; Coarasa Perez, Jose Antonio; Curé, Benoît; D'Enterria, David; De Roeck, Albert; Duarte Ramos, Fernando; Elliott-Peisert, Anna; Frisch, Benjamin; Funk, Wolfgang; Gaddi, Andrea; Gennai, Simone; Georgiou, Georgios; Gerwig, Hubert; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Glege, Frank; Gomez-Reino Garrido, Robert; Gouzevitch, Maxime; Govoni, Pietro; Gowdy, Stephen; Guiducci, Luigi; Hansen, Magnus; Harvey, John; Hegeman, Jeroen; Hegner, Benedikt; Henderson, Conor; Hesketh, Gavin; Hoffmann, Hans Falk; Honma, Alan; Innocente, Vincenzo; Janot, Patrick; Karavakis, Edward; Lecoq, Paul; Leonidopoulos, Christos; Lourenco, Carlos; Macpherson, Alick; Maki, Tuula; Malgeri, Luca; Mannelli, Marcello; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moser, Roland; Mozer, Matthias Ulrich; Mulders, Martijn; Nesvold, Erik; Nguyen, Matthew; Orimoto, Toyoko; Orsini, Luciano; Perez, Emmanuelle; Petrilli, Achille; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Polese, Giovanni; Racz, Attila; Rolandi, Gigi; Rommerskirchen, Tanja; Rovelli, Chiara; Rovere, Marco; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Segoni, Ilaria; Sharma, Archana; Siegrist, Patrice; Simon, Michal; Sphicas, Paraskevas; Spiga, Daniele; Spiropulu, Maria; Stöckli, Fabian; Stoye, Markus; Tropea, Paola; Tsirou, Andromachi; Tsyganov, Andrey; Veres, Gabor Istvan; Vichoudis, Paschalis; Voutilainen, Mikko; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Gabathuler, Kurt; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; König, Stefan; Kotlinski, Danek; Langenegger, Urs; Meier, Frank; Renker, Dieter; Rohe, Tilman; Sibille, Jennifer; Starodumov, Andrei; Bortignon, Pierluigi; Caminada, Lea; Chen, Zhiling; Cittolin, Sergio; Dissertori, Günther; Dittmar, Michael; Eugster, Jürg; Freudenreich, Klaus; Grab, Christoph; Hervé, Alain; Hintz, Wieland; Lecomte, Pierre; Lustermann, Werner; Marchica, Carmelo; Martinez Ruiz del Arbol, Pablo; Meridiani, Paolo; Milenovic, Predrag; Moortgat, Filip; Nef, Pascal; Nessi-Tedaldi, Francesca; Pape, Luc; Pauss, Felicitas; Punz, Thomas; Rizzi, Andrea; Ronga, Frederic Jean; Rossini, Marco; Sala, Leonardo; Sanchez, Ann - Karin; Sawley, Marie-Christine; Stieger, Benjamin; Tauscher, Ludwig; Thea, Alessandro; Theofilatos, Konstantinos; Treille, Daniel; Urscheler, Christina; Wallny, Rainer; Weber, Matthias; Wehrli, Lukas; Weng, Joanna; Aguiló, Ernest; Amsler, Claude; Chiochia, Vincenzo; De Visscher, Simon; Favaro, Carlotta; Ivova Rikova, Mirena; Millan Mejias, Barbara; Regenfus, Christian; Robmann, Peter; Schmidt, Alexander; Snoek, Hella; Wilke, Lotte; Chang, Yuan-Hann; Chen, Kuan-Hsin; Chen, Wan-Ting; Dutta, Suchandra; Go, Apollo; Kuo, Chia-Ming; Li, Syue-Wei; Lin, Willis; Liu, Ming-Hsiung; Liu, Zong-Kai; Lu, Yun-Ju; Wu, Jing-Han; Yu, Shin-Shan; Bartalini, Paolo; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Hou, George Wei-Shu; Hsiung, Yee; Kao, Kai-Yi; Lei, Yeong-Jyi; Lu, Rong-Shyang; Shiu, Jing-Ge; Tzeng, Yeng-Ming; Wang, Minzu; Adiguzel, Aytul; Bakirci, Mustafa Numan; Cerci, Salim; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Guler, Yalcin; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Karaman, Turker; Kayis Topaksu, Aysel; Nart, Alisah; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sogut, Kenan; Tali, Bayram; Topakli, Huseyin; Uzun, Dilber; Vergili, Latife Nukhet; Vergili, Mehmet; Zorbilmez, Caglar; Akin, Ilina Vasileva; Aliev, Takhmasib; Bilmis, Selcuk; Deniz, Muhammed; Gamsizkan, Halil; Guler, Ali Murat; Ocalan, Kadir; Ozpineci, Altug; Serin, Meltem; Sever, Ramazan; Surat, Ugur Emrah; Yildirim, Eda; Zeyrek, Mehmet; Deliomeroglu, Mehmet; Demir, Durmus; Gülmez, Erhan; Halu, Arda; Isildak, Bora; Kaya, Mithat; Kaya, Ozlem; Ozkorucuklu, Suat; Sonmez, Nasuf; Levchuk, Leonid; Bell, Peter; Bostock, Francis; Brooke, James John; Cheng, Teh Lee; Clement, Emyr; Cussans, David; Frazier, Robert; Goldstein, Joel; Grimes, Mark; Hansen, Maria; Hartley, Dominic; Heath, Greg P.; Heath, Helen F.; Huckvale, Benedickt; Jackson, James; Kreczko, Lukasz; Metson, Simon; Newbold, Dave M.; Nirunpong, Kachanon; Poll, Anthony; Senkin, Sergey; Smith, Vincent J.; Ward, Simon; Basso, Lorenzo; Bell, Ken W.; Belyaev, Alexander; Brew, Christopher; Brown, Robert M.; Camanzi, Barbara; Cockerill, David J.A.; Coughlan, John A.; Harder, Kristian; Harper, Sam; Kennedy, Bruce W.; Olaiya, Emmanuel; Petyt, David; Radburn-Smith, Benjamin Charles; Shepherd-Themistocleous, Claire; Tomalin, Ian R.; Womersley, William John; Worm, Steven; Bainbridge, Robert; Ball, Gordon; Ballin, Jamie; Beuselinck, Raymond; Buchmuller, Oliver; Colling, David; Cripps, Nicholas; Cutajar, Michael; Davies, Gavin; Della Negra, Michel; Fulcher, Jonathan; Futyan, David; Guneratne Bryer, Arlo; Hall, Geoffrey; Hatherell, Zoe; Hays, Jonathan; Iles, Gregory; Karapostoli, Georgia; Lyons, Louis; Magnan, Anne-Marie; Marrouche, Jad; Nandi, Robin; Nash, Jordan; Nikitenko, Alexander; Papageorgiou, Anastasios; Pesaresi, Mark; Petridis, Konstantinos; Pioppi, Michele; Raymond, David Mark; Rompotis, Nikolaos; Rose, Andrew; Ryan, Matthew John; Seez, Christopher; Sharp, Peter; Sparrow, Alex; Tapper, Alexander; Tourneur, Stephane; Vazquez Acosta, Monica; Virdee, Tejinder; Wakefield, Stuart; Wardrope, David; Whyntie, Tom; Barrett, Matthew; Chadwick, Matthew; Cole, Joanne; Hobson, Peter R.; Khan, Akram; Kyberd, Paul; Leslie, Dawn; Martin, William; Reid, Ivan; Teodorescu, Liliana; Hatakeyama, Kenichi; Bose, Tulika; Carrera Jarrin, Edgar; Clough, Andrew; Fantasia, Cory; Heister, Arno; St. John, Jason; Lawson, Philip; Lazic, Dragoslav; Rohlf, James; Sperka, David; Sulak, Lawrence; Avetisyan, Aram; Bhattacharya, Saptaparna; Chou, John Paul; Cutts, David; Ferapontov, Alexey; Heintz, Ulrich; Jabeen, Shabnam; Kukartsev, Gennadiy; Landsberg, Greg; Narain, Meenakshi; Nguyen, Duong; Segala, Michael; Speer, Thomas; Tsang, Ka Vang; Borgia, Maria Assunta; Breedon, Richard; Calderon De La Barca Sanchez, Manuel; Cebra, Daniel; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Cox, Peter Timothy; Dolen, James; Erbacher, Robin; Friis, Evan; Ko, Winston; Kopecky, Alexandra; Lander, Richard; Liu, Haidong; Maruyama, Sho; Miceli, Tia; Nikolic, Milan; Pellett, Dave; Robles, Jorge; Salur, Sevil; Schwarz, Thomas; Searle, Matthew; Smith, John; Squires, Michael; Tripathi, Mani; Vasquez Sierra, Ricardo; Veelken, Christian; Andreev, Valeri; Arisaka, Katsushi; Cline, David; Cousins, Robert; Deisher, Amanda; Duris, Joseph; Erhan, Samim; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Jarvis, Chad; Plager, Charles; Rakness, Gregory; Schlein, Peter; Tucker, Jordan; Valuev, Vyacheslav; Babb, John; Clare, Robert; Ellison, John Anthony; Gary, J William; Giordano, Ferdinando; Hanson, Gail; Jeng, Geng-Yuan; Kao, Shih-Chuan; Liu, Feng; Liu, Hongliang; Luthra, Arun; Nguyen, Harold; Pasztor, Gabriella; Satpathy, Asish; Shen, Benjamin C.; Stringer, Robert; Sturdy, Jared; Sumowidagdo, Suharyo; Wilken, Rachel; Wimpenny, Stephen; Andrews, Warren; Branson, James G.; Cerati, Giuseppe Benedetto; Dusinberre, Elizabeth; Evans, David; Golf, Frank; Holzner, André; Kelley, Ryan; Lebourgeois, Matthew; Letts, James; Mangano, Boris; Muelmenstaedt, Johannes; Padhi, Sanjay; Palmer, Christopher; Petrucciani, Giovanni; Pi, Haifeng; Pieri, Marco; Ranieri, Riccardo; Sani, Matteo; Sharma, Vivek; Simon, Sean; Tu, Yanjun; Vartak, Adish; Würthwein, Frank; Yagil, Avraham; Barge, Derek; Bellan, Riccardo; Campagnari, Claudio; D'Alfonso, Mariarosaria; Danielson, Thomas; Flowers, Kristen; Geffert, Paul; Incandela, Joe; Justus, Christopher; Kalavase, Puneeth; Koay, Sue Ann; Kovalskyi, Dmytro; Krutelyov, Vyacheslav; Lowette, Steven; Mccoll, Nickolas; Pavlunin, Viktor; Rebassoo, Finn; Ribnik, Jacob; Richman, Jeffrey; Rossin, Roberto; Stuart, David; To, Wing; Vlimant, Jean-Roch; Bornheim, Adolf; Bunn, Julian; Chen, Yi; Gataullin, Marat; Kcira, Dorian; Litvine, Vladimir; Ma, Yousi; Mott, Alexander; Newman, Harvey B.; Rogan, Christopher; Timciuc, Vladlen; Traczyk, Piotr; Veverka, Jan; Wilkinson, Richard; Yang, Yong; Zhu, Ren-Yuan; Akgun, Bora; Carroll, Ryan; Ferguson, Thomas; Iiyama, Yutaro; Jang, Dong Wook; Jun, Soon Yung; Liu, Yueh-Feng; Paulini, Manfred; Russ, James; Terentyev, Nikolay; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Dinardo, Mauro Emanuele; Drell, Brian Robert; Edelmaier, Christopher; Ford, William T.; Heyburn, Bernadette; Luiggi Lopez, Eduardo; Nauenberg, Uriel; Smith, James; Stenson, Kevin; Ulmer, Keith; Wagner, Stephen Robert; Zang, Shi-Lei; Agostino, Lorenzo; Alexander, James; Chatterjee, Avishek; Das, Souvik; Eggert, Nicholas; Fields, Laura Johanna; Gibbons, Lawrence Kent; Heltsley, Brian; Hopkins, Walter; Khukhunaishvili, Aleko; Kreis, Benjamin; Kuznetsov, Valentin; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Puigh, Darren; Riley, Daniel; Ryd, Anders; Shi, Xin; Sun, Werner; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Vaughan, Jennifer; Weng, Yao; Winstrom, Lucas; Wittich, Peter; Biselli, Angela; Cirino, Guy; Winn, Dave; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Apollinari, Giorgio; Atac, Muzaffer; Bakken, Jon Alan; Banerjee, Sunanda; Bauerdick, Lothar A.T.; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C.; Bloch, Ingo; Borcherding, Frederick; Burkett, Kevin; Butler, Joel Nathan; Chetluru, Vasundhara; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Demarteau, Marcel; Eartly, David P.; Elvira, Victor Daniel; Esen, Selda; Fisk, Ian; Freeman, Jim; Gao, Yanyan; Gottschalk, Erik; Green, Dan; Gunthoti, Kranti; Gutsche, Oliver; Hahn, Alan; Hanlon, Jim; Harris, Robert M.; Hirschauer, James; Hooberman, Benjamin; James, Eric; Jensen, Hans; Johnson, Marvin; Joshi, Umesh; Khatiwada, Rakshya; Kilminster, Benjamin; Klima, Boaz; Kousouris, Konstantinos; Kunori, Shuichi; Kwan, Simon; Limon, Peter; Lipton, Ron; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Mason, David; McBride, Patricia; McCauley, Thomas; Miao, Ting; Mishra, Kalanand; Mrenna, Stephen; Musienko, Yuri; Newman-Holmes, Catherine; O'Dell, Vivian; Popescu, Sorina; Pordes, Ruth; Prokofyev, Oleg; Saoulidou, Niki; Sexton-Kennedy, Elizabeth; Sharma, Seema; Soha, Aron; Spalding, William J.; Spiegel, Leonard; Tan, Ping; Taylor, Lucas; Tkaczyk, Slawek; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vidal, Richard; Whitmore, Juliana; Wu, Weimin; Yang, Fan; Yumiceva, Francisco; Yun, Jae Chul; Acosta, Darin; Avery, Paul; Bourilkov, Dimitri; Chen, Mingshui; Di Giovanni, Gian Piero; Dobur, Didar; Drozdetskiy, Alexey; Field, Richard D.; Fisher, Matthew; Fu, Yu; Furic, Ivan-Kresimir; Gartner, Joseph; Goldberg, Sean; Kim, Bockjoo; Klimenko, Sergey; Konigsberg, Jacobo; Korytov, Andrey; Kropivnitskaya, Anna; Kypreos, Theodore; Matchev, Konstantin; Mitselmakher, Guenakh; Muniz, Lana; Pakhotin, Yuriy; Prescott, Craig; Remington, Ronald; Schmitt, Michael Houston; Scurlock, Bobby; Sellers, Paul; Skhirtladze, Nikoloz; Wang, Dayong; Yelton, John; Zakaria, Mohammed; Ceron, Cristobal; Gaultney, Vanessa; Kramer, Laird; Lebolo, Luis Miguel; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bandurin, Dmitry; Bochenek, Joseph; Chen, Jie; Diamond, Brendan; Gleyzer, Sergei V; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Jenkins, Merrill; Johnson, Kurtis F.; Prosper, Harrison; Sekmen, Sezen; Veeraraghavan, Venkatesh; Baarmand, Marc M.; Dorney, Brian; Guragain, Samir; Hohlmann, Marcus; Kalakhety, Himali; Ralich, Robert; Vodopiyanov, Igor; Adams, Mark Raymond; Anghel, Ioana Maria; Apanasevich, Leonard; Bai, Yuting; Bazterra, Victor Eduardo; Betts, Russell Richard; Callner, Jeremy; Cavanaugh, Richard; Dragoiu, Cosmin; Garcia-Solis, Edmundo Javier; Gerber, Cecilia Elena; Hofman, David Jonathan; Khalatyan, Samvel; Lacroix, Florent; O'Brien, Christine; Silvestre, Catherine; Smoron, Agata; Strom, Derek; Varelas, Nikos; Akgun, Ugur; Albayrak, Elif Asli; Bilki, Burak; Cankocak, Kerem; Clarida, Warren; Duru, Firdevs; Lae, Chung Khim; McCliment, Edward; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Newsom, Charles Ray; Norbeck, Edwin; Olson, Jonathan; Onel, Yasar; Ozok, Ferhat; Sen, Sercan; Wetzel, James; Yetkin, Taylan; Yi, Kai; Barnett, Bruce Arnold; Blumenfeld, Barry; Bonato, Alessio; Eskew, Christopher; Fehling, David; Giurgiu, Gavril; Gritsan, Andrei; Guo, Zijin; Hu, Guofan; Maksimovic, Petar; Rappoccio, Salvatore; Swartz, Morris; Tran, Nhan Viet; Whitbeck, Andrew; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Grachov, Oleg; Murray, Michael; Noonan, Daniel; Radicci, Valeria; Sanders, Stephen; Wood, Jeffrey Scott; Zhukova, Victoria; Bolton, Tim; Chakaberia, Irakli; Ivanov, Andrew; Makouski, Mikhail; Maravin, Yurii; Shrestha, Shruti; Svintradze, Irakli; Wan, Zongru; Gronberg, Jeffrey; Lange, David; Wright, Douglas; Baden, Drew; Boutemeur, Madjid; Eno, Sarah Catherine; Ferencek, Dinko; Gomez, Jaime; Hadley, Nicholas John; Kellogg, Richard G.; Kirn, Malina; Lu, Ying; Mignerey, Alice; Rossato, Kenneth; Rumerio, Paolo; Santanastasio, Francesco; Skuja, Andris; Temple, Jeffrey; Tonjes, Marguerite; Tonwar, Suresh C.; Twedt, Elizabeth; Alver, Burak; Bauer, Gerry; Bendavid, Joshua; Busza, Wit; Butz, Erik; Cali, Ivan Amos; Chan, Matthew; Dutta, Valentina; Everaerts, Pieter; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Hahn, Kristan Allan; Harris, Philip; Kim, Yongsun; Klute, Markus; Lee, Yen-Jie; Li, Wei; Loizides, Constantinos; Luckey, Paul David; Ma, Teng; Nahn, Steve; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Rudolph, Matthew; Stephans, George; Sumorok, Konstanty; Sung, Kevin; Wenger, Edward Allen; Xie, Si; Yang, Mingming; Yilmaz, Yetkin; Yoon, Sungho; Zanetti, Marco; Cole, Perrie; Cooper, Seth; Cushman, Priscilla; Dahmes, Bryan; De Benedetti, Abraham; Dudero, Phillip Russell; Franzoni, Giovanni; Haupt, Jason; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Rekovic, Vladimir; Rusack, Roger; Sasseville, Michael; Singovsky, Alexander; Cremaldi, Lucien Marcus; Godang, Romulus; Kroeger, Rob; Perera, Lalith; Rahmat, Rahmat; Sanders, David A; Summers, Don; Bloom, Kenneth; Bose, Suvadeep; Butt, Jamila; Claes, Daniel R.; Dominguez, Aaron; Eads, Michael; Keller, Jason; Kelly, Tony; Kravchenko, Ilya; Lazo-Flores, Jose; Lundstedt, Carl; Malbouisson, Helena; Malik, Sudhir; Snow, Gregory R.; Baur, Ulrich; Godshalk, Andrew; Iashvili, Ia; Kharchilava, Avto; Kumar, Ashish; Shipkowski, Simon Peter; Smith, Kenneth; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Boeriu, Oana; Chasco, Matthew; Kaadze, Ketino; Reucroft, Steve; Swain, John; Wood, Darien; Zhang, Jinzhong; Anastassov, Anton; Kubik, Andrew; Odell, Nathaniel; Ofierzynski, Radoslaw Adrian; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael Henry; Stoynev, Stoyan; Velasco, Mayda; Won, Steven; Antonelli, Louis; Berry, Douglas; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kolb, Jeff; Kolberg, Ted; Lannon, Kevin; Luo, Wuming; Lynch, Sean; Marinelli, Nancy; Morse, David Michael; Pearson, Tessa; Ruchti, Randy; Slaunwhite, Jason; Valls, Nil; Warchol, Jadwiga; Wayne, Mitchell; Ziegler, Jill; Bylsma, Ben; Durkin, Lloyd Stanley; Gu, Jianhui; Hill, Christopher; Killewald, Phillip; Kotov, Khristian; Ling, Ta-Yung; Rodenburg, Marissa; Williams, Grayson; Adam, Nadia; Berry, Edmund; Elmer, Peter; Gerbaudo, Davide; Halyo, Valerie; Hebda, Philip; Hunt, Adam; Jones, John; Laird, Edward; Lopes Pegna, David; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Piroué, Pierre; Quan, Xiaohang; Saka, Halil; Stickland, David; Tully, Christopher; Werner, Jeremy Scott; Zuranski, Andrzej; Acosta, Jhon Gabriel; Huang, Xing Tao; Lopez, Angel; Mendez, Hector; Oliveros, Sandra; Ramirez Vargas, Juan Eduardo; Zatserklyaniy, Andriy; Alagoz, Enver; Barnes, Virgil E.; Bolla, Gino; Borrello, Laura; Bortoletto, Daniela; Everett, Adam; Garfinkel, Arthur F.; Gecse, Zoltan; Gutay, Laszlo; Hu, Zhen; Jones, Matthew; Koybasi, Ozhan; Laasanen, Alvin T.; Leonardo, Nuno; Liu, Chang; Maroussov, Vassili; Merkel, Petra; Miller, David Harry; Neumeister, Norbert; Potamianos, Karolos; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Jindal, Pratima; Parashar, Neeti; Boulahouache, Chaouki; Cuplov, Vesna; Ecklund, Karl Matthew; Geurts, Frank J.M.; Liu, Jinghua H.; Morales, Jafet; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Chung, Yeon Sei; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Flacher, Henning; Garcia-Bellido, Aran; Goldenzweig, Pablo; Gotra, Yury; Han, Jiyeon; Harel, Amnon; Miner, Daniel Carl; Orbaker, Douglas; Petrillo, Gianluca; Vishnevskiy, Dmitry; Zielinski, Marek; Bhatti, Anwar; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Mesropian, Christina; Yan, Ming; Atramentov, Oleksiy; Barker, Anthony; Duggan, Daniel; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Hits, Dmitry; Lath, Amitabh; Panwalkar, Shruti; Patel, Rishi; Richards, Alan; Rose, Keith; Schnetzer, Steve; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Cerizza, Giordano; Hollingsworth, Matthew; Spanier, Stefan; Yang, Zong-Chang; York, Andrew; Asaadi, Jonathan; Eusebi, Ricardo; Gilmore, Jason; Gurrola, Alfredo; Kamon, Teruki; Khotilovich, Vadim; Montalvo, Roy; Nguyen, Chi Nhan; Osipenkov, Ilya; Pivarski, James; Safonov, Alexei; Sengupta, Sinjini; Tatarinov, Aysen; Toback, David; Weinberger, Michael; Akchurin, Nural; Bardak, Cemile; Damgov, Jordan; Jeong, Chiyoung; Kovitanggoon, Kittikul; Lee, Sung Won; Mane, Poonam; Roh, Youn; Sill, Alan; Volobouev, Igor; Wigmans, Richard; Yazgan, Efe; Appelt, Eric; Brownson, Eric; Engh, Daniel; Florez, Carlos; Gabella, William; Johns, Willard; Kurt, Pelin; Maguire, Charles; Melo, Andrew; Sheldon, Paul; Velkovska, Julia; Arenton, Michael Wayne; Balazs, Michael; Boutle, Sarah; Buehler, Marc; Conetti, Sergio; Cox, Bradley; Francis, Brian; Hirosky, Robert; Ledovskoy, Alexander; Lin, Chuanzhe; Neu, Christopher; Yohay, Rachel; Gollapinni, Sowjanya; Harr, Robert; Karchin, Paul Edmund; Lamichhane, Pramod; Mattson, Mark; Milstène, Caroline; Sakharov, Alexandre; Anderson, Michael; Bachtis, Michail; Bellinger, James Nugent; Carlsmith, Duncan; Dasu, Sridhara; Efron, Jonathan; Gray, Lindsey; Grogg, Kira Suzanne; Grothe, Monika; Hall-Wilton, Richard; Herndon, Matthew; Klabbers, Pamela; Klukas, Jeffrey; Lanaro, Armando; Lazaridis, Christos; Leonard, Jessica; Lomidze, David; Loveless, Richard; Mohapatra, Ajit; Reeder, Don; Ross, Ian; Savin, Alexander; Smith, Wesley H.; Swanson, Joshua; Weinberg, Marc

2011-01-01

The Upsilon production cross section in proton-proton collisions at $\\sqrt{s}$ = 7 TeV is measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3.1 +/- 0.3 inverse picobarns. Integrated over the rapidity range |y|<2, we find the product of the Upsilon(1S) production cross section and branching fraction to dimuons to be sigma(pp to Upsilon(1S) X ) B(Upsilon(1S) to mu+ mu-) = 7.37 +/- 0.13^{+0.61}_{-0.42}pm 0.81 nb, where the first uncertainty is statistical, the second is systematic, and the third is associated with the estimation of the integrated luminosity of the data sample. This cross section is obtained assuming unpolarized Upsilon(1S) production. If the Upsilon(1S) production polarization is fully transverse or fully longitudinal the cross section changes by about 20%. We also report the measurement of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential cross sections as a function of transverse momentum and rapidity.

Renormalisation scale uncertainty in the DIS 2+1 jet cross-section

International Nuclear Information System (INIS)

Ingelman, G.

1994-05-01

The Deep Inelastic Scattering 2+1 jet cross-section is a useful observable for precision tests of QCD, e.g. measuring the strong coupling constant α s . A consistent analysis requires a good understanding of the theoretical uncertainties and one of the fundamental ones in QCD is due to the renormalisation scheme and scale ambiguity. Different methods, which have been proposed to resolve the scale ambiguity, are applied to the 2+1 jet cross-section and the uncertainty is estimated. It is shown that the uncertainty can be made smaller by choosing the jet definition in a suitable way. (orig.)

Measurements of absolute M-subshell X-ray production cross sections of Th by electron impact

Energy Technology Data Exchange (ETDEWEB)

Moy, A., E-mail: aurelien.moy@cea.fr [GM, CNRS, Université de Montpellier II, Place E. Bataillon, F-34095 Montpellier (France); CEA, DEN, DTEC, SGCS, LMAC, F-30207 Bagnols-sur-Cèze (France); Merlet, C. [GM, CNRS, Université de Montpellier II, Place E. Bataillon, F-34095 Montpellier (France); Dugne, O. [CEA, DEN, DTEC, SGCS, LMAC, F-30207 Bagnols-sur-Cèze (France)

2014-08-31

Highlights: • The M X-ray production cross sections of Th were measured by electron impact. • The M-subshell ionization cross sections of Th were determined from 3 to 38 keV. • Theoretical ionization cross-sections are in agreement with our experimental results. - Abstract: Measurements of absolute M-subshell X-ray production cross sections for element Th were made by electron impact for energies ranging from the ionization threshold up to 38 keV. Experimental data were obtained by measuring the X-ray intensity emitted from ultrathin Th films deposited onto self-supporting C backing films. The measurements were conducted with an electron microprobe using high-resolution wavelength dispersive spectrometers. Recorded intensities were converted into absolute X-ray production cross sections by means of atomic data and estimation of the number of primary electrons, target thickness, and detector efficiency. Our experimental X-ray production cross sections, the first to be reported for the M subshells of Th, are compared with X-ray production cross sections calculated with the mean of ionization cross sections obtained from the distorted-wave Born approximation. The Mα X-ray production cross section calculated is in excellent agreement with the measurements, allowing future use for standardless quantification in electron probe microanalysis.

Production Cross-Section Estimates for Strongly-Interacting Electroweak-Symmetry Breaking Sector Resonances at Particle Colliders

Science.gov (United States)

Dobado, Antonio; Guo, Feng-Kun; Llanes-Estrada, Felipe J.

2015-12-01

We are exploring a generic strongly-interacting Electroweak Symmetry Breaking Sector (EWSBS) with the low-energy effective field theory for the four experimentally known particles (W±L, ZL, h) and its dispersion-relation based unitary extension. In this contribution we provide simple estimates for the production cross-section of pairs of the EWSBS bosons and their resonances at proton-proton colliders as well as in a future e-e+ (or potentially a μ-μ+) collider with a typical few-TeV energy. We examine the simplest production mechanisms, tree-level production through a W (dominant when quantum numbers allow) and the simple effective boson approximation (in which the electroweak bosons are considered as collinear partons of the colliding fermions). We exemplify with custodial isovector and isotensor resonances at 2 TeV, the energy currently being discussed because of a slight excess in the ATLAS 2-jet data. We find it hard, though not unthinkable, to ascribe this excess to one of these WLWL rescattering resonances. An isovector resonance could be produced at a rate smaller than, but close to earlier CMS exclusion bounds, depending on the parameters of the effective theory. The ZZ excess is then problematic and requires additional physics (such as an additional scalar resonance). The isotensor one (that would describe all charge combinations) has smaller cross-section. Supported by the Spanish Excellence Network on Hadronic Physics FIS2014-57026-REDT, by Spanish Grants Universidad Complutense UCM:910309 and Ministerio de Economia y Competitividad MINECO:FPA2011-27853-C02-01, MINECO:FPA2014-53375-C2-1-P, by the Deutsche Forschungsgemeinschaft and National Natural Science Foundation of China through Funds Provided to the Sino-German CRC 110 “Symmetries and the Emergence of Structure in QCD” (NSFC Grant No. 11261130311) and by NSFC (Grant No. 11165005)

Neutron cross-sections database for amino acids and proteins analysis

Energy Technology Data Exchange (ETDEWEB)

Voi, Dante L.; Ferreira, Francisco de O.; Nunes, Rogerio Chaffin, E-mail: dante@ien.gov.br, E-mail: fferreira@ien.gov.br, E-mail: Chaffin@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Rocha, Helio F. da, E-mail: hrocha@gbl.com.br [Universidade Federal do Rio de Janeiro (IPPMG/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Pediatria

2015-07-01

Biological materials may be studied using neutrons as an unconventional tool of analysis. Dynamics and structures data can be obtained for amino acids, protein and others cellular components by neutron cross sections determinations especially for applications in nuclear purity and conformation analysis. The instrument used for this is the crystal spectrometer of the Instituto de Engenharia Nuclear (IEN-CNEN-RJ), the only one in Latin America that uses neutrons for this type of analyzes and it is installed in one of the reactor Argonauta irradiation channels. The experimentally values obtained are compared with calculated values using literature data with a rigorous analysis of the chemical composition, conformation and molecular structure analysis of the materials. A neutron cross-section database was constructed to assist in determining molecular dynamic, structure and formulae of biological materials. The database contains neutron cross-sections values of all amino acids, chemical elements, molecular groups, auxiliary radicals, as well as values of constants and parameters necessary for the analysis. An unprecedented analytical procedure was developed using the neutron cross section parceling and grouping method for data manipulation. This database is a result of measurements obtained from twenty amino acids that were provided by different manufactories and are used in oral administration in hospital individuals for nutritional applications. It was also constructed a small data file of compounds with different molecular groups including carbon, nitrogen, sulfur and oxygen, all linked to hydrogen atoms. A review of global and national scene in the acquisition of neutron cross sections data, the formation of libraries and the application of neutrons for analyzing biological materials is presented. This database has further application in protein analysis and the neutron cross-section from the insulin was estimated. (author)

Neutron cross-sections database for amino acids and proteins analysis

International Nuclear Information System (INIS)

Voi, Dante L.; Ferreira, Francisco de O.; Nunes, Rogerio Chaffin; Rocha, Helio F. da

2015-01-01

Biological materials may be studied using neutrons as an unconventional tool of analysis. Dynamics and structures data can be obtained for amino acids, protein and others cellular components by neutron cross sections determinations especially for applications in nuclear purity and conformation analysis. The instrument used for this is the crystal spectrometer of the Instituto de Engenharia Nuclear (IEN-CNEN-RJ), the only one in Latin America that uses neutrons for this type of analyzes and it is installed in one of the reactor Argonauta irradiation channels. The experimentally values obtained are compared with calculated values using literature data with a rigorous analysis of the chemical composition, conformation and molecular structure analysis of the materials. A neutron cross-section database was constructed to assist in determining molecular dynamic, structure and formulae of biological materials. The database contains neutron cross-sections values of all amino acids, chemical elements, molecular groups, auxiliary radicals, as well as values of constants and parameters necessary for the analysis. An unprecedented analytical procedure was developed using the neutron cross section parceling and grouping method for data manipulation. This database is a result of measurements obtained from twenty amino acids that were provided by different manufactories and are used in oral administration in hospital individuals for nutritional applications. It was also constructed a small data file of compounds with different molecular groups including carbon, nitrogen, sulfur and oxygen, all linked to hydrogen atoms. A review of global and national scene in the acquisition of neutron cross sections data, the formation of libraries and the application of neutrons for analyzing biological materials is presented. This database has further application in protein analysis and the neutron cross-section from the insulin was estimated. (author)

Calculations of (n,2n) reaction cross sections for Barium isotopes from 5 to 20 MeV

Science.gov (United States)

Sahan, Halide; Sahan, Muhittin; Tel, Eyyup

2017-09-01

In this study, the excitation functions of (n,2n) reactions for 30,32,34,35,37,38Ba isotopes are calculated using TALYS 1.6, EMPIRE-3.2.2, and ALICE-GDH codes based on statistical model up to 20 MeV. Moreover, the cross section for each isotope have also been estimated at 14.2 MeV using semi empirical formula developed by four different authors. The calculated and estimated cross-sections are compared with experimental cross-sections from EXFOR and compared with the evaluation data in ENDF/B-VII.1 library. Results are close agreement with the experimental data from literature.

Walkability and cardiometabolic risk factors: Cross-sectional and longitudinal associations from the Multi-Ethnic Study of Atherosclerosis.

Science.gov (United States)

Braun, Lindsay M; Rodríguez, Daniel A; Evenson, Kelly R; Hirsch, Jana A; Moore, Kari A; Diez Roux, Ana V

2016-05-01

We used data from 3227 older adults in the Multi-Ethnic Study of Atherosclerosis (2004-2012) to explore cross-sectional and longitudinal associations between walkability and cardiometabolic risk factors. In cross-sectional analyses, linear regression was used to estimate associations of Street Smart Walk Score® with glucose, triglycerides, HDL and LDL cholesterol, systolic and diastolic blood pressure, and waist circumference, while logistic regression was used to estimate associations with odds of metabolic syndrome. Econometric fixed effects models were used to estimate longitudinal associations of changes in walkability with changes in each risk factor among participants who moved residential locations between 2004 and 2012 (n=583). Most cross-sectional and longitudinal associations were small and statistically non-significant. We found limited evidence that higher walkability was cross-sectionally associated with lower blood pressure but that increases in walkability were associated with increases in triglycerides and blood pressure over time. Further research over longer time periods is needed to understand the potential for built environment interventions to improve cardiometabolic health. Copyright © 2016 Elsevier Ltd. All rights reserved.

Photoionization cross section of atomic and molecular oxygen

International Nuclear Information System (INIS)

Pareek, P.N.

1983-01-01

Photoionization cross sections of atomic oxygen and dissociative photoionization cross sections of molecular oxygen were measured from their respective thresholds to 120 angstrom by use of a photoionization mass spectrometer in conjunction with a spark light source. The photoionization cross sections O 2 + parent ion and O + fragment ion from neutral O 2 were obtained by a technique that eliminated the serious problem of identifying the true abundances of O + ions. These ions are generally formed with considerable kinetic energy and, because most mass spectrometers discriminate against energetic ions, true O + abundances are difficult to obtain. In the present work the relative cross sections for producing O + ions are obtained and normalized against the total cross sections in a spectral region where dissociative ionization is not possible. The fragmentation cross sections for O + were then obtained by subtraction of O 2 + cross sections from the known total photoionization cross sections. The results are compared with the previously published measurements. The absolute photoionization cross section of atomic oxygen sigma 8 /sub +/ was measured at 304 A. The actual number density of oxygen atoms within the ionization region was obtained by measuring the fraction of 0 2 molecules dissociated. This sigma/sub +/ at 304 angstrom was used to convert the relative photoinization cross sections, measured as a function of wavelength using a calibrated photodiode, to absolute cross sections. The results are compared with previous measurements and calculated cross sections. angstrom Rydberg series converging to the OII 4 P state was observed

Measurements of neutron capture cross sections

International Nuclear Information System (INIS)

Nakajima, Yutaka

1984-01-01

A review of measurement techniques for the neutron capture cross sections is presented. Sell transmission method, activation method, and prompt gamma-ray detection method are described using examples of capture cross section measurements. The capture cross section of 238 U measured by three different prompt gamma-ray detection methods (large liquid scintillator, Moxon-Rae detector, and pulse height weighting method) are compared and their discrepancies are resolved. A method how to derive the covariance is described. (author)

XCOM: Photon Cross Sections Database

Science.gov (United States)

SRD 8 XCOM: Photon Cross Sections Database (Web, free access)   A web database is provided which can be used to calculate photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, for any element, compound or mixture (Z <= 100) at energies from 1 keV to 100 GeV.

Graphs of the cross sections in the recommended Monte Carlo cross-section library at the Los Alamos Scientific Laboratory

International Nuclear Information System (INIS)

Soran, P.D.; Seamon, R.E.

1980-05-01

Graphs of all neutron cross sections and photon production cross sections on the Recommended Monte Carlo Cross Section (RMCCS) library have been plotted along with local neutron heating numbers. Values for anti ν, the average number of neutrons per fission, are also given

Scattering cross section for various potential systems

Directory of Open Access Journals (Sweden)

Myagmarjav Odsuren

2017-08-01

Full Text Available We discuss the problems of scattering in this framework, and show that the applied method is very useful in the investigation of the effect of the resonance in the observed scattering cross sections. In this study, not only the scattering cross sections but also the decomposition of the scattering cross sections was computed for the α–α system. To obtain the decomposition of scattering cross sections into resonance and residual continuum terms, the complex scaled orthogonality condition model and the extended completeness relation are used. Applying the present method to the α–α and α–n systems, we obtained good reproduction of the observed phase shifts and cross sections. The decomposition into resonance and continuum terms makes clear that resonance contributions are dominant but continuum terms and their interference are not negligible. To understand the behavior of observed phase shifts and the shape of the cross sections, both resonance and continuum terms are calculated.

Scattering cross section for various potential systems

Energy Technology Data Exchange (ETDEWEB)

Odsuren, Myagmarjav; Khuukhenkhuu, Gonchigdorj; Davaa, Suren [Nuclear Research Center, School of Engineering and Applied Sciences, National University of Mongolia, Ulaanbaatar (Mongolia); Kato, Kiyoshi [Nuclear Reaction Data Centre, Faculty of Science, Hokkaido University, Sapporo (Japan)

2017-08-15

We discuss the problems of scattering in this framework, and show that the applied method is very useful in the investigation of the effect of the resonance in the observed scattering cross sections. In this study, not only the scattering cross sections but also the decomposition of the scattering cross sections was computed for the α–α system. To obtain the decomposition of scattering cross sections into resonance and residual continuum terms, the complex scaled orthogonality condition model and the extended completeness relation are used. Applying the present method to the α–α and α–n systems, we obtained good reproduction of the observed phase shifts and cross sections. The decomposition into resonance and continuum terms makes clear that resonance contributions are dominant but continuum terms and their interference are not negligible. To understand the behavior of observed phase shifts and the shape of the cross sections, both resonance and continuum terms are calculated.

Resistivity of epitaxial copper nanolines with trapezoidal cross-section

International Nuclear Information System (INIS)

Lu, Zonghuan; Frey, David M.; Merkh, Thomas; Lord, Robert; Washington, Morris A.; Lu, Toh-Ming

2016-01-01

The resistivity of epitaxial Cu nanolines with line width ranging from 20 to 180 nm and line height from 40 to 50 nm was measured using a four-point probe technique. The Cu nanolines were fabricated using ebeam lithography with a polymethyl methacrylate bilayer resist system for improved line edge smoothness. The cross-section profile of the lines was examined using the focused ion beam milling technique. The results indicate that the cross-section should be more accurately described as trapezoidal rather than as rectangular. Using the trapezoidal profile, the electrical resistivity was calculated from the measured resistance data. Modeling based on the Fuchs–Sondheimer (FS) theory using the trapezoidal profile was also carried out. The results were compared with the experimentally calculated resistivity data. For Cu lines with line width less than 30 nm, the measured resistivity was shown to be up to 20% higher than the value predicted by the FS theory. Further examination of Cu lines using atomic force microscopy and scanning electron microscopy was conducted to extract the surface roughness and line edge roughness information. Their contribution to the resistivity increase was estimated to be only up to 3% for the Cu nanolines fabricated, which did not significantly contribute to the overall resistivity for Cu lines with line width less than 30 nm. Other possible factors affecting the resistivity of the Cu nanolines were also discussed, including the oxide formation on the surface of the Cu lines. - Highlights: • Epitaxial copper nanolines were fabricated using ebeam lithography. • The effect of line cross-section profiles on electrical resistivity was studied. • Trapezoidal cross−section gives better resistivity estimation for lines down to 20 nm. • Impact of surface roughness and line edge roughness to resistivity is small. • Oxidization layer has an effect on the resistivity increase.

Photon - axion conversion cross sections in an electromagnetic field

International Nuclear Information System (INIS)

Dang Van Soa; Ha Huy Bang

1999-12-01

Photon - axion conversions in static magnetic fields and in a periodic field with frequency equal to the axion mass are reconsidered in detail by Feynman methods. The differential cross sections are presented and numerical evaluations are given. It is shown that there is a resonant conversion for the considered process. Some estimates for experiments are given from our results. (author)

NNLO jet cross sections by subtraction

International Nuclear Information System (INIS)

Somogyi, G.; Bolzoni, P.; Trocsanyi, Z.

2010-06-01

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of an earlier NNLO subtraction scheme over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state. (orig.)

NNLO jet cross sections by subtraction

Energy Technology Data Exchange (ETDEWEB)

Somogyi, G.; Bolzoni, P. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Trocsanyi, Z. [CERN, Geneva (Switzerland)

2010-06-15

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of an earlier NNLO subtraction scheme over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state. (orig.)

NNLO jet cross sections by subtraction

CERN Document Server

Somogyi, Gabor; Trocsanyi, Zoltan

2010-01-01

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of the NNLO subtraction scheme of [1-4], over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state.

Differential cross sections and cross-section ratios for the electron-impact excitation of the neon 2p53s configuration

International Nuclear Information System (INIS)

Khakoo, M. A.; Wrkich, J.; Larsen, M.; Kleiban, G.; Kanik, I.; Trajmar, S.; Brunger, M.J.; Teubner, P.J.O.; Crowe, A.; Fontes, C.J.; Clark, R.E.H.; Zeman, V.; Bartschat, K.; Madison, D.H.; Srivastava, R.; Stauffer, A.D.

2002-01-01

Electron-impact differential cross-section measurements for the excitation of the 2p 5 3s configuration of Ne are reported. The Ne cross sections are obtained using experimental differential cross sections for the electron-impact excitation of the n=2 levels of atomic hydrogen [Khakoo et al., Phys. Rev. A 61, 012701-1 (1999)], and existing experimental helium differential cross-section measurements, as calibration standards. These calibration measurements were made using the method of gas mixtures (Ne and H followed by Ne and He), in which the gas beam profiles of the mixed gases are found to be the same within our experimental errors. We also present results from calculations of these differential cross sections using the R-matrix and unitarized first-order many-body theory, the distorted-wave Born approximation, and relativistic distorted-wave methods. Comparison with available experimental differential cross sections and differential cross-section ratios is also presented

Capture cross sections on unstable nuclei

Science.gov (United States)

Tonchev, A. P.; Escher, J. E.; Scielzo, N.; Bedrossian, P.; Ilieva, R. S.; Humby, P.; Cooper, N.; Goddard, P. M.; Werner, V.; Tornow, W.; Rusev, G.; Kelley, J. H.; Pietralla, N.; Scheck, M.; Savran, D.; Löher, B.; Yates, S. W.; Crider, B. P.; Peters, E. E.; Tsoneva, N.; Goriely, S.

2017-09-01

Accurate neutron-capture cross sections on unstable nuclei near the line of beta stability are crucial for understanding the s-process nucleosynthesis. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining the most relevant observables that can constrain Hauser-Feshbach statistical-model calculations of capture cross sections. Specifically, we will consider photon scattering using monoenergetic and 100% linearly polarized photon beams. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes near and far from stability will be discussed.

Status of neutron dosimetry cross sections

International Nuclear Information System (INIS)

Griffin, P.J.; Kelly, J.G.

1992-01-01

Several new cross section libraries, such as ENDF/B-VI(release 2), IRDF-90,JEF-2.2, and JENDL-3 Dosimetry, have recently been made available to the dosimetry community. the Sandia National Laboratories (SNL) Radiation Metrology Laboratory (RML) has worked with these libraries since pre-release versions were available. this paper summarizes the results of the intercomparison and testing of dosimetry cross sections. As a result of this analysis, a compendium of the best dosimetry cross sections was assembled from the available libraries for use within the SNL RML. this library, referred to as the SNLRML Library, contains 66 general dosimetry sensors and 3 special dosimeters unique to the RML sensor inventory. The SNLRML cross sections have been put into a format compatible with commonly used spectrum determination codes

Capture cross sections on unstable nuclei

Directory of Open Access Journals (Sweden)

Tonchev A.P.

2017-01-01

Full Text Available Accurate neutron-capture cross sections on unstable nuclei near the line of beta stability are crucial for understanding the s-process nucleosynthesis. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining the most relevant observables that can constrain Hauser-Feshbach statistical-model calculations of capture cross sections. Specifically, we will consider photon scattering using monoenergetic and 100% linearly polarized photon beams. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes near and far from stability will be discussed.

Graphs of the cross sections in the Alternate Monte Carlo Cross Section library at the Los Alamos Scientific Laboratory

International Nuclear Information System (INIS)

Seamon, R.E.; Soran, P.D.

1980-06-01

Graphs of all neutron cross sections and photon production cross sections on the Alternate Monte Carlo Cross Section (AMCCS) library have been plotted along with local neutron heating numbers. The values of ν-bar, the average number of neutrons per fission, are also plotted for appropriate isotopes

Bed shear stress distribution in straight channels with arbitrary cross section

DEFF Research Database (Denmark)

Christensen, Henrik Bo; Fredsøe, Jørgen

1998-01-01

The bed shear stress distribution in straight open channels is affected by mechanisms as bed curvature of the cross section profile, shear diffusion, and secondary currents. This paper compares some analytical and numerical methods to estimate the bed shear stress distribution. The methods...

Estimation of ultrasound reference values for the lower limb peripheral nerves in adults: A cross-sectional study.

Science.gov (United States)

Bedewi, Mohamed Abdelmohsen; Abodonya, Ahmed; Kotb, Mamdouh; Kamal, Sanaa; Mahmoud, Gehan; Aldossari, Khaled; Alqabbani, Abdullah; Swify, Sherine

2018-03-01

The objective of this study is to estimate the reference values for the lower limb peripheral nerves in adults.The demographics and physical characteristics of 69 adult healthy volunteers were evaluated and recorded. The estimated reference values and their correlations with the age, weight, height, body mass index (BMI) were evaluated.The cross sectional area reference values were obtained at 5 predetermined sites for 3 important lower limb peripheral nerves. Our CSA values correlated significantly with age, weight, and BMI. The normal reference values for each nerve were as follows: Tibial nerve at the popliteal fossa 19 mm ± 6.9, tibial nerve at the level of the medial malleolus 12.7 mm ± 4.5, common peroneal nerve at the popliteal fossa 9.5 mm ± 4, common peroneal nerve fibular head 8.9 mm ± 3.2, sural nerve 3.5 mm ± 1.4.The reference values for the lower limb peripheral nerves were identified. These values could be used for future management of peripheral nerve disorders.

Neutron-capture Cross Sections from Indirect Measurements

Energy Technology Data Exchange (ETDEWEB)

Escher, J E; Burke, J T; Dietrich, F S; Ressler, J J; Scielzo, N D; Thompson, I J

2011-10-18

Cross sections for compound-nuclear reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

Atlas of photoneutron cross sections obtained with monoenergetic photons

International Nuclear Information System (INIS)

Dietrich, S.S.; Berman, B.L.

1988-01-01

Photoneutron cross-section and integrated cross-section data obtained with monoenergetic photons are presented in a uniform format. All of the measured partial photoneutron cross sections, the total photoneutron cross section, and the photoneutron yield cross section are plotted as functions of the incident photon energy, as are the integrated photoneutron cross sections and their first and second moments. The values of the integrated cross sections and the moments of the integrated total cross section up to the highest photon energy for which they were measured are tabulated, as are the parameters of Lorentz curves fitted to the total photoneutron cross-section data for medium and heavy nuclei (A>50). This compilation is current as of June 1987. copyright 1988 Academic Press, Inc

Cross-Sectional Analysis of Longitudinal Mediation Processes.

Science.gov (United States)

O'Laughlin, Kristine D; Martin, Monica J; Ferrer, Emilio

2018-01-01

Statistical mediation analysis can help to identify and explain the mechanisms behind psychological processes. Examining a set of variables for mediation effects is a ubiquitous process in the social sciences literature; however, despite evidence suggesting that cross-sectional data can misrepresent the mediation of longitudinal processes, cross-sectional analyses continue to be used in this manner. Alternative longitudinal mediation models, including those rooted in a structural equation modeling framework (cross-lagged panel, latent growth curve, and latent difference score models) are currently available and may provide a better representation of mediation processes for longitudinal data. The purpose of this paper is twofold: first, we provide a comparison of cross-sectional and longitudinal mediation models; second, we advocate using models to evaluate mediation effects that capture the temporal sequence of the process under study. Two separate empirical examples are presented to illustrate differences in the conclusions drawn from cross-sectional and longitudinal mediation analyses. Findings from these examples yielded substantial differences in interpretations between the cross-sectional and longitudinal mediation models considered here. Based on these observations, researchers should use caution when attempting to use cross-sectional data in place of longitudinal data for mediation analyses.

Parametric equations for calculation of macroscopic cross sections

International Nuclear Information System (INIS)

Botelho, Mario Hugo; Carvalho, Fernando

2015-01-01

Neutronic calculations of the core of a nuclear reactor is one thing necessary and important for the design and management of a nuclear reactor in order to prevent accidents and control the reactor efficiently as possible. To perform these calculations a library of nuclear data, including cross sections is required. Currently, to obtain a cross section computer codes are used, which require a large amount of processing time and computer memory. This paper proposes the calculation of macroscopic cross section through the development of parametric equations. The paper illustrates the proposal for the case of macroscopic cross sections of absorption (Σa), which was chosen due to its greater complexity among other cross sections. Parametric equations created enable, quick and dynamic way, the determination of absorption cross sections, enabling the use of them in calculations of reactors. The results show efficient when compared with the absorption cross sections obtained by the ALPHA 8.8.1 code. The differences between the cross sections are less than 2% for group 2 and less than 0.60% for group 1. (author)

Spectral history correction of microscopic cross sections for the PBR using the slowing down balance

International Nuclear Information System (INIS)

Hudson, N.; Rahnema, F.; Ougouag, A. M.; Gougar, H. D.

2006-01-01

A method has been formulated to account for depletion effects on microscopic cross sections within a Pebble Bed Reactor (PBR) spectral zone without resorting to calls to the spectrum (cross section generation) code or relying upon table interpolation between data at different values of burnup. In this method, infinite medium microscopic cross sections, fine group fission spectra, and modulation factors are pre-computed at selected isotopic states. This fine group information is used with the local spectral zone nuclide densities to generate new cross sections for each spectral zone. The local spectrum used to generate these microscopic cross sections is estimated through the solution to the cell-homogenized, infinite medium slowing down balance equation during the flux calculation. This technique is known as Spectral History Correction (SHC), and it is formulated to specifically account for burnup within a spectral zone. It was found that the SHC technique accurately calculates local broad group microscopic cross sections with local burnup information. Good agreement is obtained with cross sections generated directly by the cross section generator. Encouraging results include improvement in the converged fuel cycle eigenvalue, the power peaking factor, and the flux. It was also found that the method compared favorably to the benchmark problem in terms of the computational speed. (authors)

Low Energy Neutrino Cross Sections

International Nuclear Information System (INIS)

Zeller, G.P.

2004-01-01

Present atmospheric and accelerator based neutrino oscillation experiments operate at low neutrino energies (Ev ∼ 1 GeV) to access the relevant regions of oscillation parameter space. As such, they require precise knowledge of the cross sections for neutrino-nucleon interactions in the sub-to-few GeV range. At these energies, neutrinos predominantly interact via quasi-elastic (QE) or single pion production processes, which historically have not been as well studied as the deep inelastic scattering reactions that dominate at higher energies.Data on low energy neutrino cross sections come mainly from bubble chamber, spark chamber, and emulsion experiments that collected their data decades ago. Despite relatively poor statistics and large neutrino flux uncertainties, these measurements provide an important and necessary constraint on Monte Carlo models in present use. The following sections discuss the current status of QE, resonant single pion, coherent pion, and single kaon production cross section measurements at low energy

Group cross-section processing method and common nuclear group cross-section library based on JENDL-3 nuclear data file

International Nuclear Information System (INIS)

Hasegawa, Akira

1991-01-01

A common group cross-section library has been developed in JAERI. This system is called 'JSSTDL-295n-104γ (neutron:295 gamma:104) group constants library system', which is composed of a common 295n-104γ group cross-section library based on JENDL-3 nuclear data file and its utility codes. This system is applicable to fast and fusion reactors. In this paper, firstly outline of group cross-section processing adopted in Prof. GROUCH-G/B system is described in detail which is a common step for all group cross-section library generation. Next available group cross-section libraries developed in Japan based on JENDL-3 are briefly reviewed. Lastly newly developed JSSTDL library system is presented with some special attention to the JENDL-3 data. (author)

Neutron-capture cross sections from indirect measurements

Directory of Open Access Journals (Sweden)

Scielzo N.D.

2012-02-01

Full Text Available Cross sections for compound-nuclear reactions reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f reactions, but need to be improved upon for applications to capture reactions.

Curves and tables of neutron cross sections

International Nuclear Information System (INIS)

Nakagawa, Tsuneo; Asami, Tetsuo; Yoshida, Tadashi

1990-07-01

Neutron cross-section curves from the Japanese Evaluated Nuclear Data Library version 3, JENDL-3, are presented in both graphical and tabular form for users in a wide range of application areas in the nuclear energy field. The contents cover cross sections for all the main reactions induced by neutrons with an energy below 20 MeV including; total, elastic scattering, capture, and fission, (n,n'), (n,2n), (n,3n), (n,α), (n,p) reactions. The 2200 m/s cross-section values, resonance integrals, and Maxwellian- and fission-spectrum averaged cross sections are also tabulated. (author)

Quantifying and predicting interpretational uncertainty in cross-sections

Science.gov (United States)

Randle, Charles; Bond, Clare; Monaghan, Alison; Lark, Murray

2015-04-01

or over estimate the elevation of the bedrock. More complex analysis was completed in the form of linear mixed effects modelling. The modelling was used to determine if there were any correlations between the error and any other parameter recorded in the questionnaire, section or the initial dataset. This has resulted in the determination of both data based and interpreter based controls on uncertainty, adding insight into how uncertainty can be predicted, as well as how interpretation workflows can be improved. Our results will inform further experiments across a wide variety of geological situations to build understanding and best practice workflows for cross-section interpretation to reduce uncertainty.

Accurate e/sup -/-He cross sections below 19 eV

Energy Technology Data Exchange (ETDEWEB)

Nesbet, R K [International Business Machines Corp., San Jose, CA (USA). Research Lab.

1979-04-14

Variational calculations of e/sup -/-He s- and p-wave phaseshifts, together with the Born formula for higher partial waves, are used to give the scattering amplitude to within one per cent estimated accuracy for energies less than 19 eV. Coefficients are given of cubic spline fits to auxiliary functions that provide smooth interpolation of the estimated accurate phaseshifts. Data given here make it possible to obtain the differential scattering cross section over the energy range considered from simple formulae.

High ET jet cross sections at CDF

International Nuclear Information System (INIS)

Flaugher, B.

1996-08-01

The inclusive jet cross section for p anti p collisions at √s = 1.8 TeV as measured by the CDF collaboration will be presented. Preliminary CDF measurements of the Σ E T cross section at √s = 1.8 TeV and the central inclusive jet cross section at √s = 0.630 TeV will also be shown

Unified description of neutron-, proton- and photon-induced fission cross sections in intermediate energy region

International Nuclear Information System (INIS)

Fukahori, Tokio; Iwamoto, Osamu; Chiba, Satoshi

2003-01-01

For an accelerator-driven nuclear waste transmutation system, it is very important to estimate sub-criticality of core system for feasibility and design study of the system. The fission cross section in the intermediate energy range has an important role. A program FISCAL has been developed to calculate neutron-, proton- and photon-induced fission cross sections in the energy region from several tens of MeV to 3 GeV. FISCAL adopts the systematics considering experimental data for Ag- 243 Am. It is found that unified description of neutron-, proton- and photon-induced fission cross sections is available. (author)

Effects of space-dependent cross sections on core physics parameters for compact fast spectrum space power reactors

International Nuclear Information System (INIS)

Lell, R.M.; Hanan, N.A.

1987-01-01

Effects of multigroup neutron cross section generation procedures on core physics parameters for compact fast spectrum reactors have been examined. Homogeneous and space-dependent multigroup cross section sets were generated in 11 and 27 groups for a representative fast reactor core. These cross sections were used to compute various reactor physics parameters for the reference core. Coarse group structure and neglect of space-dependence in the generation procedure resulted in inaccurate computations of reactor flux and power distributions and in significant errors regarding estimates of core reactivity and control system worth. Delayed neutron fraction was insensitive to cross section treatment, and computed reactivity coefficients were only slightly sensitive. However, neutron lifetime was found to be very sensitive to cross section treatment. Deficiencies in multigroup cross sections are reflected in core nuclear design and, consequently, in system mechanical design

Cross-section sensitivity and uncertainty analysis of the FNG copper benchmark experiment

Energy Technology Data Exchange (ETDEWEB)

Kodeli, I., E-mail: ivan.kodeli@ijs.si [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Kondo, K. [Karlsruhe Institute of Technology, Postfach 3640, D-76021 Karlsruhe (Germany); Japan Atomic Energy Agency, Rokkasho-mura (Japan); Perel, R.L. [Racah Institute of Physics, Hebrew University of Jerusalem, IL-91904 Jerusalem (Israel); Fischer, U. [Karlsruhe Institute of Technology, Postfach 3640, D-76021 Karlsruhe (Germany)

2016-11-01

A neutronics benchmark experiment on copper assembly was performed end 2014–beginning 2015 at the 14-MeV Frascati neutron generator (FNG) of ENEA Frascati with the objective to provide the experimental database required for the validation of the copper nuclear data relevant for ITER design calculations, including the related uncertainties. The paper presents the pre- and post-analysis of the experiment performed using cross-section sensitivity and uncertainty codes, both deterministic (SUSD3D) and Monte Carlo (MCSEN5). Cumulative reaction rates and neutron flux spectra, their sensitivity to the cross sections, as well as the corresponding uncertainties were estimated for different selected detector positions up to ∼58 cm in the copper assembly. This permitted in the pre-analysis phase to optimize the geometry, the detector positions and the choice of activation reactions, and in the post-analysis phase to interpret the results of the measurements and the calculations, to conclude on the quality of the relevant nuclear cross-section data, and to estimate the uncertainties in the calculated nuclear responses and fluxes. Large uncertainties in the calculated reaction rates and neutron spectra of up to 50%, rarely observed at this level in the benchmark analysis using today's nuclear data, were predicted, particularly high for fast reactions. Observed C/E (dis)agreements with values as low as 0.5 partly confirm these predictions. Benchmark results are therefore expected to contribute to the improvement of both cross section as well as covariance data evaluations.

Recommended evaluation procedure for photonuclear cross section

Energy Technology Data Exchange (ETDEWEB)

Lee, Young-Ouk; Chang, Jonghwa; Fukahori, Tokio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

In order to generate photonuclear cross section library for the necessary applications, data evaluation is combined with theoretical evaluation, since photonuclear cross sections measured cannot provide all necessary data. This report recommends a procedure consisting of four steps: (1) analysis of experimental data, (2) data evaluation, (3) theoretical evaluation and, if necessary, (4) modification of results. In the stage of analysis, data obtained by different measurements are reprocessed through the analysis of their discrepancies to a representative data set. In the data evaluation, photonuclear absorption cross sections are evaluated via giant dipole resonance and quasi-deutron mechanism. With photoabsorption cross sections from the data evaluation, theoretical evaluation is applied to determine various decay channel cross sections and emission spectra using equilibrium and preequilibrium mechanism. After this, the calculated results are compared with measured data, and in some cases the results are modified to better describe measurements. (author)

Recommended activation detector cross sections (RNDL-82)

International Nuclear Information System (INIS)

Bondars, Kh.Ya.; Lapenas, A.A.

1984-01-01

The results of the comparison between measured and calculated average cross sections in 5 benchmark experiments are presented. Calculations have been based on the data from 10 libraries of evaluated cross sections. The recommended library (RNDL-82) of the activation detector cross sections has been created on the basis of the comparison. RNDL-82, including 26 reactions, and the basic characteristics of the detectors are presented. (author)

Activation cross section and isomeric cross section ratios for the (n ,2 n ) reaction on 153Eu

Science.gov (United States)

Luo, Junhua; Jiang, Li; Li, Suyuan

2017-10-01

The 153Eu(n ,2 n ) m1,m2,g152Eu cross section was measured by means of the activation technique at three neutron energies in the range 13-15 MeV. The quasimonoenergetic neutron beam was formed via the 3H(d ,n ) 4He reaction, in the Pd-300 Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). The activities induced in the reaction products were measured using high-resolution γ-ray spectroscopy. The cross section of the population of the second high-spin (8-) isomeric state was measured along with the reaction cross section populating both the ground (3-) and the first isomeric state (0-). Cross sections were also evaluated theoretically using the numerical code TALYS-1.8, with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature.

Association between subjective risk perception and objective risk estimation in patients with atrial fibrillation: a cross-sectional study.

Science.gov (United States)

Zweiker, David; Zweiker, Robert; Winkler, Elisabeth; Roesch, Konstantina; Schumacher, Martin; Stepan, Vinzenz; Krippl, Peter; Bauer, Norbert; Heine, Martin; Reicht, Gerhard; Zweiker, Gudrun; Sprenger, Martin; Watzinger, Norbert

2017-09-25

Oral anticoagulation (OAC) is state-of-the-art therapy for atrial fibrillation (AF), the most common arrhythmia worldwide. However, little is known about the perception of patients with AF and how it correlates with risk scores used by their physicians. Therefore, we correlated patients' estimates of their own stroke and bleeding risk with the objectively predicted individual risk using CHA 2 DS 2 -VASc and HAS-BLED scores. Cross-sectional prevalence study using convenience sampling and telephone follow-up. Eight hospital departments and one general practitioner in Austria. Patients' perception of stroke and bleeding risk was opposed to commonly used risk scoring. Patients with newly diagnosed AF and indication for anticoagulation. Comparison of subjective risk perception with CHA 2 DS 2 -VASc and HAS-BLED scores showing possible discrepancies between subjective and objective risk estimation. Patients' judgement of their own knowledge on AF and education were also correlated with accuracy of subjective risk appraisal. Ninety-one patients (age 73±11 years, 45% female) were included in this study. Subjective stroke and bleeding risk estimation did not correlate with risk scores (ρ=0.08 and ρ=0.17). The majority of patients (57%) underestimated the individual stroke risk. Patients feared stroke more than bleeding (67% vs 10%). There was no relationship between accurate perception of stroke and bleeding risks and education level. However, we found a correlation between the patients' judgement of their own knowledge of AF and correct assessment of individual stroke risk (ρ=0.24, p=0.02). During follow-up, patients experienced the following events: death (n=5), stroke (n=2), bleeding (n=1). OAC discontinuation rate despite indication was 3%. In this cross-sectional analysis of OAC-naive patients with AF, we found major differences between patients' perceptions and physicians' assessments of risks and benefits of OAC. To ensure shared decision-making and informed

Cross-section uncertainty study of the NET shielding blanket

International Nuclear Information System (INIS)

Jaeger, J.F.

1990-11-01

The Next European Torus (NET) is foreseen as the next step in the European development towards the controlled use of thermonuclear fusion. Detail design of the shielding blanket protecting the peripherals, more especially the super-conducting coils, is well advanced. A cross-section uncertainty, i.e. a study of the expected inaccuracy due to the nuclear cross-section data, has been done for the neutron-gamma reactions in the insulation of the coils for such a design. As an extension of previous work on the NET shielding blanket (e.g. MCNP calculations), it was deemed necessary to estimate the accuracy attainable with transport codes in view of the uncertainties in microscopic cross-sections. The code used, SENSIBL, is based on perturbation theory and uses covariance files, COVFILS-2, for the cross-section data. This necessitates forward and adjoint flux calculations with a transport code (e.g. ONEDANT, TRISM) and folding the information contained in these coupled fluxes with the accuracy estimates of the evaluators of the ENDF/B-V files. Transport, P 5 S 12 , calculations were done with the ONEDANT code, for a shielding blanket design with 714 MW plasma fusion power. Several runs were done to obtain well converged forward and adjoint fluxes (ca. 1%). The forward and adjoint integral responses agree to 2%, which is consistent with the above accuracy. The n-γ response was chosen as it is typical of the general accuracy and is available for all materials considered. The present version of SENSIBL allows direct use of the geometric files of ONEDANT (or TRISM) which simplifies the input. Covariance data is not available at present in COVFILS-2 for all of the materials considered. Only H, C, N, O, Al, Si, Fe, Ni, and Pb could be considered, the big absentee being copper. The resulting uncertainty for the neutron-gamma reactions in the insulation of the coil was found to be 17%. Simulating copper by aluminium produces a negligible increase in the uncertainty, mainly

Activation cross section and isomeric cross-section ratio for the (n,2n) reaction on {sup 132,134}Ba

Energy Technology Data Exchange (ETDEWEB)

Luo, Junhua [Hexi Univ., Zhangye (China). School of Physics and Electromechanical Engineering; Hexi Univ., Zhangye (China). Inst. of New Energy; Wu, Chunlei; Jiang, Li [Chinese Academy of Engineering Physics, Mianyang (China). Inst. of Nuclear Physics and Chemistry; Li, Suyuan [Hexi Univ., Zhangye (China). Inst. of New Energy

2017-07-01

Cross sections of the {sup 132}Ba(n,2n){sup 131m,g}Ba and {sup 134}Ba(n,2n){sup 133m,g}Ba reactions and their isomeric cross section ratios σ{sub m}/σ{sub g} have been measured by means of the activation technique at three neutron energies in the range 13-15 MeV. BaCO{sub 3} samples and Nb monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The quasimonoenergetic neutrons beam were produced via the {sup 3}H(d,n){sup 4}He reaction at the Pd-300 Neutron Generator of the Chinese Academy of Engineering Physics (CAEP). The activities induced in the reaction products were measured using high-resolution γ ray spectroscopy. The pure cross section of the ground-state was derived from the absolute cross section of the metastable state and the residual nuclear decay analysis. Cross sections were also evaluated theoretically using the numerical nuclear model code, TALYS-1.8 with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature.

Updated Higgs cross section at approximate N3LO

International Nuclear Information System (INIS)

Bonvini, Marco; Ball, Richard D; Forte, Stefano; Marzani, Simone; Ridolfi, Giovanni

2014-01-01

We update our estimate of the cross section for Higgs production in gluon fusion at next-to-next-to-next-to-leading order in α s in view of the recent full computation of the result in the soft limit for infinite top mass, which determines a previously unknown constant. We briefly discuss the phenomenological implications. Results are available through the updated version of the ggHiggs code. (paper)

Updated Higgs cross section at approximate N3LO

International Nuclear Information System (INIS)

Bonvini, Marco; Ball, Richard D.; Marzani, Simone

2014-04-01

We update our estimate of the cross section for Higgs production in gluon fusion at next-to-next-to-next-to-leading order (N 3 LO) in α s in view of the recent full computation of the result in the soft limit for infinite top mass, which determines a previously unknown constant. We briefly discuss the phenomenological implications. Results are available through the updated version of the ggHiggs code.

Dielectronic recombination cross sections for H-like ions

International Nuclear Information System (INIS)

Pindzola, M.S.; Badnell, N.R.; Griffin, D.C.

1990-01-01

Dielectronic recombination cross sections for several H-like atomic ions are calculated in an isolated-resonance, distorted-wave approximation. Fine-structure and configuration-interaction effects are examined in detail for the O 7+ cross section. Hartree-Fock, intermediate-coupled, multiconfiguration dielectronic recombination cross sections for O 7+ are then compared with the recent experimental measurements obtained with the Test Storage Ring in Heidelberg. The cross-section spectra line up well in energy and the shape of the main resonance structures are comparable. The experimental integrated cross sections differ by up to 20% from theory, but this may be due in part to uncertainties in the electron distribution function

Comparative analysis among several cross section sets

International Nuclear Information System (INIS)

Caldeira, A.D.

1983-01-01

Critical parameters were calculated using the one dimensional multigroup transport theory for several cross section sets. Calculations have been performed for water mixtures of uranium metal, plutonium metal and uranium-thorium oxide, and for metallics systems, to determine the critical dimensions of geometries (sphere and cylinder). For this aim, the following cross section sets were employed: 1) multigroup cross section sets obtained from the GAMTEC-II code; 2) the HANSEN-ROACH cross section sets; 3) cross section sets from the ENDF/B-IV, processed by the NJOY code. Finally, we have also calculated the corresponding critical radius using the one dimensional multigroup transport DTF-IV code. The numerical results agree within a few percent with the critical values obtained in the literature (where the greatest discrepancy occured in the critical dimensions of water mixtures calculated with the values generated by the NJOY code), a very good results in comparison with similar works. (Author) [pt

Fission cross section measurements at intermediate energies

International Nuclear Information System (INIS)

Laptev, Alexander

2005-01-01

The activity in intermediate energy particle induced fission cross-section measurements of Pu, U isotopes, minor actinides and sub-actinides in PNPI of Russia is reviewed. The neutron-induced fission cross-section measurements are under way in the wide energy range of incident neutrons from 0.5 MeV to 200 MeV at the GNEIS facility. In number of experiments at the GNEIS facility, the neutron-induced fission cross sections were obtained for many nuclei. In another group of experiments the proton-induced fission cross-section have been measured for proton energies ranging from 200 to 1000 MeV at 100 MeV intervals using the proton beam of PNPI synchrocyclotron. (author)

Partial cross sections near the higher resonances

International Nuclear Information System (INIS)

Falk-Vairant, P.; Valladas, G.

1961-07-01

As a continuation of the report given at the 10. Rochester Conference, recent measurements of charge-exchange cross section and π 0 production in π - -p interactions are presented here. Section 1 gives a summary of the known results for the elastic, inelastic, and charge-exchange cross sections. Section 2 presents the behavior of the cross sections in the T=1/2 state, in order to discuss the resonances at 600 and 890 MeV. Section 3 discusses the charge-exchange scattering and the interference term between the T=1/2 and T=3/2 states. Section 4 presents some comments on inelastic processes. This report is reprinted from 'Reviews of Modern Physics', Vol. 33, No. 3, 362-367, July, 1961

Electron-detachment cross sections of halogen negative-ion projectiles for inertial confinement fusion

Science.gov (United States)

Sant'Anna, M. M.; Zappa, F.; Santos, A. C. F.; de Barros, A. L. F.; Wolff, W.; Coelho, L. F. S.; de Castro Faria, N. V.

2004-07-01

Negative-ion beams have recently been suggested as sources of high-energy heavy atoms to be used as drivers for inertial confinement fusion (ICF). Owing to their electron affinities limited to a few eV, anions can be efficiently photo-detached in the vicinity of the fusion chamber, with the resulting high-velocity neutral projectiles following ballistic trajectories towards the hydrogen pellet target. Electron-detachment cross sections are needed as parameters to estimate the beam attenuation in the path from the ion source to the hydrogen pellet. Halogen anions are possible projectile choices. In this paper we present experimental data for total electron-detachment cross sections for F-, Cl-, Br- and I- ions incident on N2, in the 0.94-74 keV u-1 energy range. Our measurements can benchmark theory on anion electron detachment at intermediate to high velocities. Comparison between different projectiles shows very similar collision velocity dependencies. A simple geometrical scaling is presented, providing an estimate for electron-detachment cross sections at the MeV u-1 energy range. The presented scaling indicates that the vacuum requirements due to the use of halogen anions for ICF are less critical than previously suggested.

Electron-detachment cross sections of halogen negative-ion projectiles for inertial confinement fusion

International Nuclear Information System (INIS)

Sant'Anna, M M; Zappa, F; Santos, A C F; Barros, A L F de; Wolff, W; Coelho, L F S; Faria, N V de Castro

2004-01-01

Negative-ion beams have recently been suggested as sources of high-energy heavy atoms to be used as drivers for inertial confinement fusion (ICF). Owing to their electron affinities limited to a few eV, anions can be efficiently photo-detached in the vicinity of the fusion chamber, with the resulting high-velocity neutral projectiles following ballistic trajectories towards the hydrogen pellet target. Electron-detachment cross sections are needed as parameters to estimate the beam attenuation in the path from the ion source to the hydrogen pellet. Halogen anions are possible projectile choices. In this paper we present experimental data for total electron-detachment cross sections for F - , Cl - , Br - and I - ions incident on N 2 , in the 0.94-74 keV u -1 energy range. Our measurements can benchmark theory on anion electron detachment at intermediate to high velocities. Comparison between different projectiles shows very similar collision velocity dependencies. A simple geometrical scaling is presented, providing an estimate for electron-detachment cross sections at the MeV u -1 energy range. The presented scaling indicates that the vacuum requirements due to the use of halogen anions for ICF are less critical than previously suggested

Limit moments for non circular cross-section (elliptical) pipe bends

International Nuclear Information System (INIS)

Spence, J.

1977-01-01

A number of experiment studies have been reported or are underway which investigate limit moments applied to pipe bends. Some theoretical work is also available. However, most of the work has been confined to nominally circular cross-section bends and little account has been taken of the practical problem of manufacturing tolerances. Many methods of manufacture result in bends which are not circular in cross-section but have an oval or elliptical shape. The present paper extends previous analyses on circular bends to cater for initially elliptical cross-sections. The loading is primarily in plane bending but out of plane is also considered and several independent methods are presented. No previous information is known to the authors. Upper and lower bound limit moments are derived first of all from existing linear elastic analyses and secondly upper bound moments are derived via a plastic analogy from existing stationary creep results. It is also shown that the creep information on design factors for bends can be used to obtain a reasonable estimate of the complete moment/strain behaviour of a bend or indeed a system. (Auth.)

A simple method to approximate liver size on cross-sectional images using living liver models

International Nuclear Information System (INIS)

Muggli, D.; Mueller, M.A.; Karlo, C.; Fornaro, J.; Marincek, B.; Frauenfelder, T.

2009-01-01

Aim: To assess whether a simple. diameter-based formula applicable to cross-sectional images can be used to calculate the total liver volume. Materials and methods: On 119 cross-sectional examinations (62 computed tomography and 57 magnetic resonance imaging) a simple, formula-based method to approximate the liver volume was evaluated. The total liver volume was approximated measuring the largest craniocaudal (cc), ventrodorsal (vd), and coronal (cor) diameters by two readers and implementing the equation: Vol estimated =ccxvdxcorx0.31. Inter-rater reliability, agreement, and correlation between liver volume calculation and virtual liver volumetry were analysed. Results: No significant disagreement between the two readers was found. The formula correlated significantly with the volumetric data (r > 0.85, p < 0.0001). In 81% of cases the error of the approximated volume was <10% and in 92% of cases <15% compared to the volumetric data. Conclusion: Total liver volume can be accurately estimated on cross-sectional images using a simple, diameter-based equation.

Cross sections for double K-shell ionization in slow heavy ion-atom collisions, ch. 4

International Nuclear Information System (INIS)

Hoogkamer, T.P.; Woerlee, P.H.; Saris, F.W.

1977-01-01

Cross sections for Ksub(αα) X-ray production have been measured in collisions of 200 keV N + → NH 3 , N 2 , H 2 O; O + → NH 3 , H 2 O and 200, 400, 600 keV Ne 2+ → Ne. Fluorescence yields for Ksub(αα) two-electron one-photon transitions have been estimated for N and O, whereas for Ne, theoretical values for the fluorescence yield are available. We have used these to obtain double K-shell ionizzation cross sections which are compared to calculated cross section based on the theory for rotational coupling in the transient quasimolecular state

Classical scattering cross section in sputtering transport theory

International Nuclear Information System (INIS)

Zhang Zhulin

2002-01-01

For Lindhard scaling interaction potential scattering commonly used in sputtering theory, the authors analyzed the great difference between Sigmund's single power and the double power cross sections calculated. The double power cross sections can give a much better approximation to the Born-Mayer scattering in the low energy region (m∼0.1). In particular, to solve the transport equations by K r -C potential interaction given by Urbassek few years ago, only the double power cross sections (m∼0.1) can yield better approximate results for the number of recoils. Therefore, the Sigmund's single power cross section might be replaced by the double power cross sections in low energy collision cascade theory

The European activation file EAF-3 with neutron activation and transmutation cross-sections

International Nuclear Information System (INIS)

Kopecky, J.; Kamp, H.A.J. van der; Gruppelaar, H.; Nierop, D.

1992-09-01

The work performed to obtain the 3rd version of European Activation File (EAF-3) is described, containing cross-sections for neutron induced reactions (0-20 MeV energy range), mainly for use in fusion reactor technology. The starter file was version EAF-2. The present version contains cross-section data for all target nuclides which have half-lives longer than 0.5 days including up to curium (60 targets). Cross-sections to isomeric states are listed separately and if the isomers have a half-life longer than 0.5 days they are also includes as targets. The EAF-3 contains 729 target nuclides with 12,899 reactions with non-zero cross-sections (>10 -7 b) below 20 MeV. A provisional uncertainty file has been generated for all reactions in a one-energy group structure for threshold reactions and in a two-groups structure for (n, γ) reactions. The error estimates for this file were adopted either from experimental information or from systematics. (author). 42 refs., 1 fig., 8 tabs

Cross section data for ionization of important cyanides

International Nuclear Information System (INIS)

Kaur, Jaspreet; Antony, Bobby

2015-01-01

Highlights: • Multi centre spherical complex optical potential formalism used to find the CS. • Effective method (CSP-ic) to derive ionization contribution from inelastic CS. • Result shows excellent accord with previous results and consistent behaviour. • Maiden attempt to find CS for many cyanide molecules. • Strong correlation observed between peak of ionization with target properties. - Abstract: This article presents cross section calculations for interactions of important cyanides with electrons possessing energies beginning from ionization threshold of the target molecule to 5 keV. These data are pursued to meet the ever increasing demand for cross sections by the relevant atomic and molecular community for modelling astrophysical, atmospheric and technological domains. The calculations have been executed using an amalgam of multi centre spherical complex optical potential (MSCOP) formalism and complex scattering potential-ionization contribution (CSP-ic) method. Cross sections are compared with experimental and theoretical data wherever available. Strong correlations are observed for the cross sections which affirms consistent and reliable cross sections. Isomeric effect has been interpreted using variation of cross section with structure and target properties. Our cross sections will be tabulated in atomic collision database for use in modelling various statistical and dynamical quantities.

Cross section data for ionization of important cyanides

Energy Technology Data Exchange (ETDEWEB)

Kaur, Jaspreet; Antony, Bobby, E-mail: bka.ism@gmail.com

2015-11-15

Highlights: • Multi centre spherical complex optical potential formalism used to find the CS. • Effective method (CSP-ic) to derive ionization contribution from inelastic CS. • Result shows excellent accord with previous results and consistent behaviour. • Maiden attempt to find CS for many cyanide molecules. • Strong correlation observed between peak of ionization with target properties. - Abstract: This article presents cross section calculations for interactions of important cyanides with electrons possessing energies beginning from ionization threshold of the target molecule to 5 keV. These data are pursued to meet the ever increasing demand for cross sections by the relevant atomic and molecular community for modelling astrophysical, atmospheric and technological domains. The calculations have been executed using an amalgam of multi centre spherical complex optical potential (MSCOP) formalism and complex scattering potential-ionization contribution (CSP-ic) method. Cross sections are compared with experimental and theoretical data wherever available. Strong correlations are observed for the cross sections which affirms consistent and reliable cross sections. Isomeric effect has been interpreted using variation of cross section with structure and target properties. Our cross sections will be tabulated in atomic collision database for use in modelling various statistical and dynamical quantities.

Accurate Cross Sections for Microanalysis

OpenAIRE

Rez, Peter

2002-01-01

To calculate the intensity of x-ray emission in electron beam microanalysis requires a knowledge of the energy distribution of the electrons in the solid, the energy variation of the ionization cross section of the relevant subshell, the fraction of ionizations events producing x rays of interest and the absorption coefficient of the x rays on the path to the detector. The theoretical predictions and experimental data available for ionization cross sections are limited mainly to K shells of a...

Criticality benchmark comparisons leading to cross-section upgrades

International Nuclear Information System (INIS)

Alesso, H.P.; Annese, C.E.; Heinrichs, D.P.; Lloyd, W.R.; Lent, E.M.

1993-01-01

For several years criticality benchmark calculations with COG. COG is a point-wise Monte Carlo code developed at Lawrence Livermore National Laboratory (LLNL). It solves the Boltzmann equation for the transport of neutrons and photons. The principle consideration in developing COG was that the resulting calculation would be as accurate as the point-wise cross-sectional data, since no physics computational approximations were used. The objective of this paper is to report on COG results for criticality benchmark experiments in concert with MCNP comparisons which are resulting in corrections an upgrades to the point-wise ENDL cross-section data libraries. Benchmarking discrepancies reported here indicated difficulties in the Evaluated Nuclear Data Livermore (ENDL) cross-sections for U-238 at thermal neutron energy levels. This led to a re-evaluation and selection of the appropriate cross-section values from several cross-section sets available (ENDL, ENDF/B-V). Further cross-section upgrades anticipated

The method of purging applied to repeated cross-sectional data: Practical applications using logistic and linear regression analysis

NARCIS (Netherlands)

Grotenhuis, H.F. te; Eisinga, R.N.; Scheepers, P.L.H.

2004-01-01

In cross-sectional survey research, it is quite common to estimate the(standardized) effect of independent variable(s) on a dependent variable. However, if repeated cross-sectional data are available, much is to be gained if the consequences of these effects on longitudinal social change are

Cross section homogenization analysis for a simplified Candu reactor

International Nuclear Information System (INIS)

Pounders, Justin; Rahnema, Farzad; Mosher, Scott; Serghiuta, Dumitru; Turinsky, Paul; Sarsour, Hisham

2008-01-01

The effect of using zero current (infinite medium) boundary conditions to generate bundle homogenized cross sections for a stylized half-core Candu reactor problem is examined. Homogenized cross section from infinite medium lattice calculations are compared with cross sections homogenized using the exact flux from the reference core environment. The impact of these cross section differences is quantified by generating nodal diffusion theory solutions with both sets of cross sections. It is shown that the infinite medium spatial approximation is not negligible, and that ignoring the impact of the heterogeneous core environment on cross section homogenization leads to increased errors, particularly near control elements and the core periphery. (authors)

Fission cross section measurements of actinides at LANSCE

Energy Technology Data Exchange (ETDEWEB)

Tovesson, Fredrik [Los Alamos National Laboratory; Laptev, Alexander B [Los Alamos National Laboratory; Hill, Tony S [INL

2010-01-01

Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the {sup 235}U standard. Recent measurements include the {sup 233,238}U, {sup 239,242}Pu and {sup 243}Am neutron-induced fission cross sections. In this paper preliminary results for cross section data of {sup 243}Am and {sup 233}U will be presented.

Library of neutron reaction cross-sections in the ABBN-93 constant system

International Nuclear Information System (INIS)

Zabrodskaya, S.V.; Korchagina, Zh.A.; Koshcheev, V.N.; Nikolaev, M.N.; Tsibulya, A.M.

2001-01-01

The library of neutron reaction group cross-sections in the ABBN-93 constant set is described. The format used for data representation, the content and purpose of the sub-libraries and their practical application in the SCALE criticality safety estimation system are discussed. (author)

Compilation of cross-sections. Pt. 1

International Nuclear Information System (INIS)

Flaminio, V.; Moorhead, W.G.; Morrison, D.R.O.; Rivoire, N.

1983-01-01

A compilation of integral cross-sections for hadronic reactions is presented. This is an updated version of CERN/HERA 79-1, 79-2, 79-3. It contains all data published up to the beginning of 1982, but some more recent data have also been included. Plots of the cross-sections versus incident laboratory momentum are also given. (orig.)

Compilation of cross-sections. Pt. 4

International Nuclear Information System (INIS)

Alekhin, S.I.; Ezhela, V.V.; Lugovsky, S.B.; Tolstenkov, A.N.; Yushchenko, O.P.; Baldini, A.; Cobal, M.; Flaminio, V.; Capiluppi, P.; Giacomelli, G.; Mandrioli, G.; Rossi, A.M.; Serra, P.; Moorhead, W.G.; Morrison, D.R.O.; Rivoire, N.

1987-01-01

This is the fourth volume in our series of data compilations on integrated cross-sections for weak, electromagnetic, and strong interaction processes. This volume covers data on reactions induced by photons, neutrinos, hyperons, and K L 0 . It contains all data published up to June 1986. Plots of the cross-sections versus incident laboratory momentum are also given. (orig.)

Validation of elastic cross section models for space radiation applications

Energy Technology Data Exchange (ETDEWEB)

Werneth, C.M., E-mail: charles.m.werneth@nasa.gov [NASA Langley Research Center (United States); Xu, X. [National Institute of Aerospace (United States); Norman, R.B. [NASA Langley Research Center (United States); Ford, W.P. [The University of Tennessee (United States); Maung, K.M. [The University of Southern Mississippi (United States)

2017-02-01

The space radiation field is composed of energetic particles that pose both acute and long-term risks for astronauts in low earth orbit and beyond. In order to estimate radiation risk to crew members, the fluence of particles and biological response to the radiation must be known at tissue sites. Given that the spectral fluence at the boundary of the shielding material is characterized, radiation transport algorithms may be used to find the fluence of particles inside the shield and body, and the radio-biological response is estimated from experiments and models. The fidelity of the radiation spectrum inside the shield and body depends on radiation transport algorithms and the accuracy of the nuclear cross sections. In a recent study, self-consistent nuclear models based on multiple scattering theory that include the option to study relativistic kinematics were developed for the prediction of nuclear cross sections for space radiation applications. The aim of the current work is to use uncertainty quantification to ascertain the validity of the models as compared to a nuclear reaction database and to identify components of the models that can be improved in future efforts.

Evaluation of fusion-evaporation cross-section calculations

Science.gov (United States)

Blank, B.; Canchel, G.; Seis, F.; Delahaye, P.

2018-02-01

Calculated fusion-evaporation cross sections from five different codes are compared to experimental data. The present comparison extents over a large range of nuclei and isotopic chains to investigate the evolution of experimental and calculated cross sections. All models more or less overestimate the experimental cross sections. We found reasonable agreement by using the geometrical average of the five model calculations and dividing the average by a factor of 11.2. More refined analyses are made for example for the 100Sn region.

NDS multigroup cross section libraries

International Nuclear Information System (INIS)

DayDay, N.

1981-12-01

A summary description and documentation of the multigroup cross section libraries which exist at the IAEA Nuclear Data Section are given in this report. The libraries listed are available either on tape or in printed form. (author)

Neutron-induced fission cross sections

International Nuclear Information System (INIS)

Weigmann, H.

1991-01-01

In the history of fission research, neutron-induced fission has always played the most important role. The practical importance of neutron-induced fission rests upon the fact that additional neutrons are produced in the fission process, and thus a chain reaction becomes possible. The practical applications of neutron-induced fission will not be discussed in this chapter, but only the physical properties of one of its characteristics, namely (n,f) cross sections. The most important early summaries on the subject are the monograph edited by Michaudon which also deals with the practical applications, the earlier review article on fission by Michaudon, and the review by Bjornholm and Lynn, in which neutron-induced fission receives major attention. This chapter will attempt to go an intermediate way between the very detailed theoretical treatment in the latter review and the cited monograph which emphasizes the applied aspects and the techniques of fission cross-section measurements. The more recent investigations in the field will be included. Section II will survey the properties of cross sections for neutron-induced fission and also address some special aspects of the experimental methods applied in their measurement. Section Ill will deal with the formal theory of neutron-induced nuclear reactions for the resolved resonance region and the region of statistical nuclear reactions. In Section IV, the fission width, or fission transmission coefficient, will be discussed in detail. Section V will deal with the broader structures due to incompletely damped vibrational resonances, and in particular will address the special case of thorium and neighboring isotopes. Finally, Section VI will briefly discuss parity violation effects in neutron-induced fission. 74 refs., 14 figs., 3 tabs

ENDF/B-5 fission product cross section evaluations

International Nuclear Information System (INIS)

Schenter, R.E.; England, T.R.

1979-12-01

Cross section evaluations were made for the 196 fission product nuclides on the ENDF/B-5 data files. Most of the evaluations involve updating the capture cross sections of the important absorbers for fast and thermal reactor systems. This included updating thermal values, resonance integrals, resonance parameter sets, and fast capture cross sections. For the fast capture results generalized least-squares calculations were made with the computer code FERRET. Input for these cross section adjustments included nuclear models calculations and both integral and differential experimental data results. The differential cross sections and their uncertainties were obtained from the CSIRS library. Integral measurement results came from CFRMF and STEK Assemblies 500, 1000, 2000, 3000, 4000. Comparisons of these evaluations with recent capture measurements are shown. 15 figures, 10 tables

Nuclear fission and neutron-induced fission cross-sections

Energy Technology Data Exchange (ETDEWEB)

James, G.D.; Lynn, J.E.; Michaudon, A.; Rowlands, J.; de Saussure, G.

1981-01-01

A general presentation of current knowledge of the fission process is given with emphasis on the low energy fission of actinide nuclei and neutron induced fission. The need for and the required accuracy of fission cross section data in nuclear energy programs are discussed. A summary is given of the steps involved in fission cross section measurement and the range of available techniques. Methods of fission detection are described with emphasis on energy dependent changed and detector efficiency. Examples of cross section measurements are given and data reduction is discussed. The calculation of fission cross sections is discussed and relevant nuclear theory including the formation and decay of compound nuclei and energy level density is introduced. A description of a practical computation of fission cross sections is given.

Model cross section calculations using LAHET

International Nuclear Information System (INIS)

Prael, R.E.

1992-01-01

The current status of LAHET is discussed. The effect of a multistage preequilibrium exciton model following the INC is examined for neutron emission benchmark calculations, as is the use of a Fermi breakup model for light nuclei rather than an evaporation model. Comparisons are made also for recent fission cross section experiments, and a discussion of helium production cross sections is presented

Interference analysis of fission cross section

International Nuclear Information System (INIS)

Toshkov, S.A.; Yaneva, N.B.

1976-01-01

The formula for the reaction cross-section based on the R-matrix formalism considering the interference between the two neighbouring resonances, referred to the same value of total momentum was used for the analysis of the cross-section of resonance neutron induced fission of 230Pu. The experimental resolution and thermal motion of the target nuclei were accounted for numerical integration

Total cross sections for electron scattering by He

International Nuclear Information System (INIS)

De Heer, F.J.; Jansen, R.H.J.

1977-01-01

A set of total cross sections for scattering of electrons by He has been evaluated over the energy range of zero to 3000 eV by means of the analysis of experiments and theories on total cross sections for elastic scattering, ionisation and excitation, and on differential cross sections for elastic and inelastic scattering. Between 0 and 19.8 eV, where no inelastic processes occur, the total cross sections for scattering are equal to those for elastic scattering. Above 19.8 eV total cross sections for scattering of electrons have been evaluated by adding those for ionisation, excitation and elastic scattering. The total cross sections thus obtained are probably accurate to about 5% over a large part of the energy range. They appear to be in very good agreement with the recent experimental results of Blaauw et al. (J. Phys. B.; 10:L299 (1977)). The present results have already proved useful for application in the dispersion relation for forward scattering in electron-helium collisions. (author)

Intra-Generational Mobility and Repeated Cross-Sections: A Three Country Validation Exercise

NARCIS (Netherlands)

Cruces, G.; Lanjouw, P.F.; Lucchetti, L.; Perova, E.; Vakis, R.; Viollaz, M.

2015-01-01

This paper validates a recently proposed method to estimate intra-generational poverty transitions through repeated cross-sectional surveys. The technique allows the creation of a “synthetic panel” – done by predicting future or past household income or consumption using a set of simple modeling and

The γ*γ* total cross section and the BFKL pomeron at e+e-colliders

International Nuclear Information System (INIS)

Bartels, J.

1996-08-01

We present a numerical estimate of the γ*γ* total cross section at LEP and at the designed e + e - next linear collider (NLC), based upon the BFKL Pomeron. We find for the linear collider that the event rate is substantial provided electrons scattered under small angles can be detected, and a measurement of this cross section provides an excellent test of the BFKL Pomeron. For LEP, although the number of events is substantially smaller, and initial study of this process is feasible. (orig.)

Cross Sections for Inner-Shell Ionization by Electron Impact

Energy Technology Data Exchange (ETDEWEB)

Llovet, Xavier, E-mail: xavier@ccit.ub.edu [Centres Científics i Tecnològics, Universitat de Barcelona, Lluís Solé i Sabarís 1-3, 08028 Barcelona (Spain); Powell, Cedric J. [Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8370 (United States); Salvat, Francesc [Facultat de Física (ECM and ICC), Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Jablonski, Aleksander [Institute of Physical Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224 Warsaw (Poland)

2014-03-15

An analysis is presented of measured and calculated cross sections for inner-shell ionization by electron impact. We describe the essentials of classical and semiclassical models and of quantum approximations for computing ionization cross sections. The emphasis is on the recent formulation of the distorted-wave Born approximation by Bote and Salvat [Phys. Rev. A 77, 042701 (2008)] that has been used to generate an extensive database of cross sections for the ionization of the K shell and the L and M subshells of all elements from hydrogen to einsteinium (Z = 1 to Z = 99) by electrons and positrons with kinetic energies up to 1 GeV. We describe a systematic method for evaluating cross sections for emission of x rays and Auger electrons based on atomic transition probabilities from the Evaluated Atomic Data Library of Perkins et al. [Lawrence Livermore National Laboratory, UCRL-ID-50400, 1991]. We made an extensive comparison of measured K-shell, L-subshell, and M-subshell ionization cross sections and of Lα x-ray production cross sections with the corresponding calculated cross sections. We identified elements for which there were at least three (for K shells) or two (for L and M subshells) mutually consistent sets of cross-section measurements and for which the cross sections varied with energy as expected by theory. The overall average root-mean-square deviation between the measured and calculated cross sections was 10.9% and the overall average deviation was −2.5%. This degree of agreement between measured and calculated ionization and x-ray production cross sections was considered to be very satisfactory given the difficulties of these measurements.

Isotopic dependence of photoneutron cross sections around Strontium (Z=38) and Cesium (Z=55) nuclei

International Nuclear Information System (INIS)

Nakamura, T.; Uno, Y.; Yamadera, A.; Kase, T.

1992-01-01

We measured the average cross sections of (γ,n) reactions for 84 Sr, 86 Sr, 88 Sr, 85 Rb, 87 Rb, 98 Ru and 104 Ru isotopes in giant resonance region (9 to 25 MeV) using Bremsstrahlung radiation of 60 MeV maximum energy. We investigated the isotopic dependence of the average (γ,n) cross sections in giant resonance region from our experimental data and those estimated from other experimental data for Ge, Se, Zr, Mo, Sn, Te, Ce, Nd and Sm isotopes. As a result, we found that the average cross section data become highest for nuclei of neutron magic number of N = 50 and 82 except for Mo nucleus

Floodplain Cross Section Lines

Data.gov (United States)

Department of Homeland Security — This table is required for any Digital Flood Insurance Rate Map database where cross sections are shown on the Flood Insurance Rate Map (FIRM). Normally any FIRM...

Considering sampling strategy and cross-section complexity for estimating the uncertainty of discharge measurements using the velocity-area method

Science.gov (United States)

Despax, Aurélien; Perret, Christian; Garçon, Rémy; Hauet, Alexandre; Belleville, Arnaud; Le Coz, Jérôme; Favre, Anne-Catherine

2016-02-01

Streamflow time series provide baseline data for many hydrological investigations. Errors in the data mainly occur through uncertainty in gauging (measurement uncertainty) and uncertainty in the determination of the stage-discharge relationship based on gaugings (rating curve uncertainty). As the velocity-area method is the measurement technique typically used for gaugings, it is fundamental to estimate its level of uncertainty. Different methods are available in the literature (ISO 748, Q + , IVE), all with their own limitations and drawbacks. Among the terms forming the combined relative uncertainty in measured discharge, the uncertainty component relating to the limited number of verticals often includes a large part of the relative uncertainty. It should therefore be estimated carefully. In ISO 748 standard, proposed values of this uncertainty component only depend on the number of verticals without considering their distribution with respect to the depth and velocity cross-sectional profiles. The Q + method is sensitive to a user-defined parameter while it is questionable whether the IVE method is applicable to stream-gaugings performed with a limited number of verticals. To address the limitations of existing methods, this paper presents a new methodology, called FLow Analog UnceRtainty Estimation (FLAURE), to estimate the uncertainty component relating to the limited number of verticals. High-resolution reference gaugings (with 31 and more verticals) are used to assess the uncertainty component through a statistical analysis. Instead of subsampling purely randomly the verticals of these reference stream-gaugings, a subsampling method is developed in a way that mimicks the behavior of a hydrometric technician. A sampling quality index (SQI) is suggested and appears to be a more explanatory variable than the number of verticals. This index takes into account the spacing between verticals and the variation of unit flow between two verticals. To compute the

A Pebble Bed Reactor cross section methodology

International Nuclear Information System (INIS)

Hudson, Nathanael H.; Ougouag, Abderrafi M.; Rahnema, Farzad; Gougar, Hans

2009-01-01

A method is presented for the evaluation of microscopic cross sections for the Pebble Bed Reactor (PBR) neutron diffusion computational models during convergence to an equilibrium (asymptotic) fuel cycle. This method considers the isotopics within a core spectral zone and the leakages from such a zone as they arise during reactor operation. The randomness of the spatial distribution of fuel grains within the fuel pebbles and that of the fuel and moderator pebbles within the core, the double heterogeneity of the fuel, and the indeterminate burnup of the spectral zones all pose a unique challenge for the computation of the local microscopic cross sections. As prior knowledge of the equilibrium composition and leakage is not available, it is necessary to repeatedly re-compute the group constants with updated zone information. A method is presented to account for local spectral zone composition and leakage effects without resorting to frequent spectrum code calls. Fine group data are pre-computed for a range of isotopic states. Microscopic cross sections and zone nuclide number densities are used to construct fine group macroscopic cross sections, which, together with fission spectra, flux modulation factors, and zone buckling, are used in the solution of the slowing down balance to generate a new or updated spectrum. The microscopic cross-sections are then re-collapsed with the new spectrum for the local spectral zone. This technique is named the Spectral History Correction (SHC) method. It is found that this method accurately recalculates local broad group microscopic cross sections. Significant improvement in the core eigenvalue, flux, and power peaking factor is observed when the local cross sections are corrected for the effects of the spectral zone composition and leakage in two-dimensional PBR test problems.

Transport cross section for small-angle scattering

International Nuclear Information System (INIS)

D'yakonov, M.I.; Khaetskii, A.V.

1991-01-01

Classical mechanics is valid for describing potential scattering under the conditions (1) λ much-lt α and (2) U much-gt ℎυ/α, where λ is the de Broglie wavelength, α is the characteristic size of the scatterer, U is the characteristic value of the potential energy, and υ is the velocity of the scattered particle. The second of these conditions means that the typical value of the classical scattering angle is far larger than the diffraction angle λ/α. In this paper the authors show that this second condition need not hold in a derivation of the transport cross section. In other words, provided that the condition λ much-lt α holds, it is always possible to calculate the transport cross section from the expressions of classical mechanics, even in the region U approx-lt ℎυ/α, where the scattering is diffractive,and the differential cross section is greatly different from the classical cross section. The transport cross section is found from the classical expression even in the anticlassical case U much-lt ℎυ/α, where the Born approximation can be used

Nonelastic-scattering cross sections of elemental nickel

International Nuclear Information System (INIS)

Smith, A.B.; Guenther, P.T.; Whalen, J.F.

1980-06-01

Neutron total cross sections of elemental nickel were measured from 1.3 to 4.5 MeV, at intervals of approx. 50 keV, with resolutions of 30 to 50 keV and to accuracies of 1 to 2.5%. Neutron differential-elastic-scattering cross sections were measured from 1.45 to 3.8 MeV, at intervals and with resolutions comparable to those of the total cross sections, and to accuracies of 3 to 5%. The nonelastic-scattering cross section is derived from the measured values to accuracies of greater than or equal to 6%. The experimental results are compared with previously reported values as represented by ENDF/B-V, and areas of consistency and discrepancy, noted. The measured results are shown to be in good agreement with the predictions of a model previously reported by the authors. 4 figures, 1 table

Measurement of Scattering Cross Section with a Spectrophotometer with an Integrating Sphere Detector.

Science.gov (United States)

Gaigalas, A K; Wang, Lili; Karpiak, V; Zhang, Yu-Zhong; Choquette, Steven

2012-01-01

A commercial spectrometer with an integrating sphere (IS) detector was used to measure the scattering cross section of microspheres. Analysis of the measurement process showed that two measurements of the absorbance, one with the cuvette placed in the normal spectrometer position, and the second with the cuvette placed inside the IS, provided enough information to separate the contributions from scattering and molecular absorption. Measurements were carried out with microspheres with different diameters. The data was fitted with a model consisting of the difference of two terms. The first term was the Lorenz-Mie (L-M) cross section which modeled the total absorbance due to scattering. The second term was the integral of the L-M differential cross section over the detector acceptance angle. The second term estimated the amount of forward scattered light that entered the detector. A wavelength dependent index of refraction was used in the model. The agreement between the model and the data was good between 300 nm and 800 nm. The fits provided values for the microsphere diameter, the concentration, and the wavelength dependent index of refraction. For wavelengths less than 300 nm, the scattering cross section had significant spectral structure which was inversely related to the molecular absorption. This work addresses the measurement and interpretation of the scattering cross section for wavelengths between 300 nm and 800 nm.

Vibrational enhancement of total breakup cross sections

International Nuclear Information System (INIS)

Haftel, M.I.; Lim, T.K.

1984-01-01

This paper considers the role of multi-two-body bound states, namely vibrational excitations, on total three-body breakup cross-sections. Total cross-sections are usually easy to measure, and they play a fundamental role in chemical kinetics. (orig.)

Target dependence of K+-nucleus total cross sections

International Nuclear Information System (INIS)

Jiang, M.F.; Ernst, D.J.; Chen, C.M.

1995-01-01

We investigate the total cross section and its target dependence for K + -nucleus scattering using a relativistic momentum-space optical potential model which incorporates relativistically normalized wave functions, invariant two-body amplitudes, covariant kinematics, and an exact full-Fermi averaging integral. The definition of the total cross section in the presence of a Coulomb interaction is reviewed and the total cross section is calculated in a way that is consistent with what is extracted from experiment. In addition, the total cross sections for a nucleus and for the deuteron are calculated utilizing the same theory. This minimizes the dependence of the ratio of these cross sections on the details of the theory. The model dependence of the first-order optical potential calculations is investigated. The theoretical results are found to be systematically below all existing data

Tables of RCN-2 fission-product cross section evaluation

International Nuclear Information System (INIS)

Gruppelaar, H.

1979-05-01

This report (continuation of ECN-13 and ECN-33) describes the third part of the RCN-2 evaluation of neutron cross sections for fission product nuclides in KEDAK format. It contains evaluated data for nine nuclides, i.e. 142 Nd, 143 Nd, 144 Nd, 145 Nd, 146 Nd, 147 Nd, 148 Nd, 150 Nd and 147 Pm. Most emphasis has been given to the evaluation of the radiative capture cross section, in order to provide a data base for adjustment calculations using results of integral measurements. Short evaluation reports are given for this cross section. The evaluated capture cross sections are compared with recent experimental differential and integral data. Graphs are given of the capture cross sections at neutron energies above 1 keV, in which also adjusted point cross sections, based upon integral STEK and CFRMF data have been plotted. Moreover, the results are compared with those of the well-known ENDF/B-IV evaluation for fission product nucleides. Finally, evaluation summaries are given, which include tables of other important neutron cross sections, such as the total, elastic scattering and inelastic scattering cross sections

Uranium, thorium and bismuth photofission cross sections at high energies

International Nuclear Information System (INIS)

Tavares, O.A.P.

1973-01-01

The U 238 , Th 232 and Bi 209 photofission using nuclear emulsion technique for fission fragments detection is presented. The photofission cross sections were measured using Bremsstrahlung photon which were produced irradiating thin tungsten radiators with electrons accelerated at the energy range from 1,0 to 5,5 GeV in the ''Deutsches Elektronen Synchrotron'' (Hamburg), and aluminium radiator with electrons accelarated at 16,0 GeV in Stanford Linear Accelerator Center. A special revelation technique for nuclear emulsion pellicles loaded with uranium and thorium, allowed the discrimination between alpha particles tracks and fission fragments tracks. The results show a decrease in the cross sections, which is in good agreement, within experimental errors, with the conclusions of other authors. The estimations from the two-step mechanism for high energy nuclear reactions (intranuclear cascade followed by fission-evaporation competition) show that, the primary interaction according to the photomesonic model and the quasi-deuteron photon interaction are sufficient to explain the general behavior exhibited by photofission cross sections for investigated nuclei. The calculations show a resonant structure around 300 MeV, with a width at half maximum of 200 MeV, and another not so pronounced, near to 700 MeV. (Author) [pt

Microscopic cross sections: An utopia?

Energy Technology Data Exchange (ETDEWEB)

Hilaire, S. [CEA Bruyeres-le-Chatel, DIF 91 (France); Koning, A.J. [Nuclear Research and Consultancy Group, PO Box 25, 1755 ZG Petten (Netherlands); Goriely, S. [Institut d' Astronomie et d' Astrophysique, Universite Libre de Bruxelles, Campus de la Plaine, CP 226, 1050 Brussels (Belgium)

2010-07-01

The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations. While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

Microscopic cross sections: An utopia?

International Nuclear Information System (INIS)

Hilaire, S.; Koning, A.J.; Goriely, S.

2010-01-01

The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations.While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

Multilevel parametrization of fissile nuclei resonance cross sections

International Nuclear Information System (INIS)

Lukyanov, A.A.; Kolesov, V.V.; Janeva, N.

1987-01-01

Because the resonance interference has an important influence on the resonance structure of neutron cross sections energy dependence at lowest energies, multilevel scheme of the cross section parametrization which take into account the resonance interference is used for the description with the same provisions in the regions of the interferential maximum and minimum of the resonance cross sections of the fissile nuclei

A Physics-Based Engineering Approach to Predict the Cross Section for Advanced SRAMs

Science.gov (United States)

Li, Lei; Zhou, Wanting; Liu, Huihua

2012-12-01

This paper presents a physics-based engineering approach to estimate the heavy ion induced upset cross section for 6T SRAM cells from layout and technology parameters. The new approach calculates the effects of radiation with junction photocurrent, which is derived based on device physics. The new and simple approach handles the problem by using simple SPICE simulations. At first, the approach uses a standard SPICE program on a typical PC to predict the SPICE-simulated curve of the collected charge vs. its affected distance from the drain-body junction with the derived junction photocurrent. And then, the SPICE-simulated curve is used to calculate the heavy ion induced upset cross section with a simple model, which considers that the SEU cross section of a SRAM cell is more related to a “radius of influence” around a heavy ion strike than to the physical size of a diffusion node in the layout for advanced SRAMs in nano-scale process technologies. The calculated upset cross section based on this method is in good agreement with the test results for 6T SRAM cells processed using 90 nm process technology.

Calculation of atom displacement cross section for structure material

International Nuclear Information System (INIS)

Liu Ping; Xu Yiping

2015-01-01

The neutron radiation damage in material is an important consideration of the reactor design. The radiation damage of materials mainly comes from atom displacements of crystal structure materials. The reaction cross sections of charged particles, cross sections of displacements per atom (DPA) and KERMA are the basis of radiation damage calculation. In order to study the differences of DPA cross sections with different codes and different evaluated nuclear data libraries, the DPA cross sections for structure materials were calculated with UNF and NJOY codes, and the comparisons of results were given. The DPA cross sections from different evaluated nuclear data libraries were compared. And the comparison of DPA cross sections between NJOY and Monte Carlo codes was also done. The results show that the differences among these evaluated nuclear data libraries exist. (authors)

Absolute total and one and two electron transfer cross sections for Ar8+ on Ar as a function of energy

International Nuclear Information System (INIS)

Vancura, J.; Kostroun, V.O.

1992-01-01

The absolute total and one and two electron transfer cross sections for Ar 8+ on Ar were measured as a function of projectile laboratory energy from 0.090 to 0.550 keV/amu. The effective one electron transfer cross section dominates above 0.32 keV/amu, while below this energy, the effective two electron transfer starts to become appreciable. The total cross section varies by a factor over the energy range explored. The overall error in the cross section measurement is estimated to be ± 15%

Preparation of next generation set of group cross sections. 3

International Nuclear Information System (INIS)

Kaneko, Kunio

2002-03-01

This fiscal year, based on the examination result about the evaluation energy range of heavy element unresolved resonance cross sections, the upper energy limit of the energy range, where ultra-fine group cross sections are produced, was raised to 50 keV, and an improvement of the group cross section processing system was promoted. At the same time, reflecting the result of studies carried out till now, a function producing delayed neutron data was added to the general-purpose group cross section processing system , thus the preparation of general purpose group cross section processing system has been completed. On the other hand, the energy structure, data constitution and data contents of next generation group cross section set were determined, and the specification of a 151 groups next generation group cross section set was defined. Based on the above specification, a concrete library format of the next generation cross section set has been determined. After having carried out the above-described work, using the general-purpose group cross section processing system , which was complete in this study, with use of the JENDL-3. 2 evaluated nuclear data, the 151 groups next generation group cross section of 92 nuclides and the ultra fine group resonance cross section library for 29 nuclides have been prepared. Utilizing the 151 groups next generation group cross section set and the ultra-fine group resonance cross-section library, a bench mark test calculation of fast reactors has been performed by using an advanced lattice calculation code. It was confirmed, by comparing the calculation result with a calculation result of continuous energy Monte Carlo code, that the 151 groups next generation cross section set has sufficient accuracy. (author)

Comprehensive neutron cross-section and secondary energy distribution uncertainty analysis for a fusion reactor

International Nuclear Information System (INIS)

Gerstl, S.A.W.; LaBauve, R.J.; Young, P.G.

1980-05-01

On the example of General Atomic's well-documented Power Generating Fusion Reactor (PGFR) design, this report exercises a comprehensive neutron cross-section and secondary energy distribution (SED) uncertainty analysis. The LASL sensitivity and uncertainty analysis code SENSIT is used to calculate reaction cross-section sensitivity profiles and integral SED sensitivity coefficients. These are then folded with covariance matrices and integral SED uncertainties to obtain the resulting uncertainties of three calculated neutronics design parameters: two critical radiation damage rates and a nuclear heating rate. The report documents the first sensitivity-based data uncertainty analysis, which incorporates a quantitative treatment of the effects of SED uncertainties. The results demonstrate quantitatively that the ENDF/B-V cross-section data files for C, H, and O, including their SED data, are fully adequate for this design application, while the data for Fe and Ni are at best marginally adequate because they give rise to response uncertainties up to 25%. Much higher response uncertainties are caused by cross-section and SED data uncertainties in Cu (26 to 45%), tungsten (24 to 54%), and Cr (up to 98%). Specific recommendations are given for re-evaluations of certain reaction cross-sections, secondary energy distributions, and uncertainty estimates

Positive Scattering Cross Sections using Constrained Least Squares

International Nuclear Information System (INIS)

Dahl, J.A.; Ganapol, B.D.; Morel, J.E.

1999-01-01

A method which creates a positive Legendre expansion from truncated Legendre cross section libraries is presented. The cross section moments of order two and greater are modified by a constrained least squares algorithm, subject to the constraints that the zeroth and first moments remain constant, and that the standard discrete ordinate scattering matrix is positive. A method using the maximum entropy representation of the cross section which reduces the error of these modified moments is also presented. These methods are implemented in PARTISN, and numerical results from a transport calculation using highly anisotropic scattering cross sections with the exponential discontinuous spatial scheme is presented

SENSIT: a cross-section and design sensitivity and uncertainty analysis code. [In FORTRAN for CDC-7600, IBM 360

Energy Technology Data Exchange (ETDEWEB)

Gerstl, S.A.W.

1980-01-01

SENSIT computes the sensitivity and uncertainty of a calculated integral response (such as a dose rate) due to input cross sections and their uncertainties. Sensitivity profiles are computed for neutron and gamma-ray reaction cross sections of standard multigroup cross section sets and for secondary energy distributions (SEDs) of multigroup scattering matrices. In the design sensitivity mode, SENSIT computes changes in an integral response due to design changes and gives the appropriate sensitivity coefficients. Cross section uncertainty analyses are performed for three types of input data uncertainties: cross-section covariance matrices for pairs of multigroup reaction cross sections, spectral shape uncertainty parameters for secondary energy distributions (integral SED uncertainties), and covariance matrices for energy-dependent response functions. For all three types of data uncertainties SENSIT computes the resulting variance and estimated standard deviation in an integral response of interest, on the basis of generalized perturbation theory. SENSIT attempts to be more comprehensive than earlier sensitivity analysis codes, such as SWANLAKE.

Heisenberg rise of total cross sections

International Nuclear Information System (INIS)

Ezhela, V.V.; Yushchenko, O.P.

1988-01-01

It is shown that on the basis of the original idea of Heisenberg on the quasiclassical picture of extended particle interactions one can construct a satisfactory description of the total cross sections, elastic cross sections, elastic diffractive slopes and mean charged multiplicities in the cm energy range from 5 to 900 GeV, and produce reasonable extrapolations up to several tens of TeV. 14 refs.; 7 figs.; 2 tabs

Effective thermal neutron absorption cross section for heterogeneous mixture

International Nuclear Information System (INIS)

Gabanska, B.; Igielski, A.; Krynicka-Drozdowicz, E.; Woznicka, U.

1989-01-01

The first estimations (basing on Umiastowski's theory) of the influence of the sample heterogeneity of the effective thermal neutron absorption cross section were compared with the results obtained for the homogeneous mixture which components and concentration were the same as those of the heterogeneous sample. An experiment was prepared to determine how good this estimate is. Three artificial heterogeneous cylindrical samples (2R = H = 9 cm) were manufactured from pure silver cylinders embedded in plexiglass, keeping the Ag content and varying the size of cylinders (2R = H = 1.0 cm, 0.6 cm and 0.4 cm). Calculations performed show that the experimental effect of the sample heterogeneity can be significant. 5 figs., 5 tabs, 11 refs. (author)

Heavy flavour production cross-sections from fixed target to collider energies

CERN Document Server

Wöhri, H K

2004-01-01

We review the hadro-production data presently available on charm and beauty absolute production cross-sections, collected by experiments at CERN, DESY and Fermilab. After correcting the published values, in particular for the 'time evolution' of the branching ratios, the measurements are compared to LO pQCD calculations performed with Pythia. as a function of the collision energy, using the latest parametrizations of the parton distribution functions. We then estimate, including nuclear effects on the parton densities, the charm and beauty production cross-sections relevant for future measurements at SPS, RHIC and LHC energies, in proton-proton and nucleus-nucleus collisions. We also compare some indirect charm measurements, done using leptonic decays, to the others and we briefly address the importance of beauty production as a feed-down mechanism of J/ psi production. (34 refs).

FENDL/E-2.0. Evaluated nuclear data library of neutron-nucleus interaction cross sections and photon production cross sections and photon-atom interaction cross sections for fusion applications. Version 1, March 1997. Summary documentation

International Nuclear Information System (INIS)

Pashchenko, A.B.; Wienke, H.

1998-01-01

This document presents the description of a physical tape containing the basic evaluated nuclear data library of neutron-nucleus interaction cross sections, photon production cross sections and photon-atom interaction cross sections for fusion applications. It is part of the evaluated nuclear data library for fusion applications FENDL-2. The data are available cost-free from the Nuclear Data Section upon request. The data can also be retrieved by the user via online access through international computer networks. (author)

Modeling and Analysis of a Piezoelectric Energy Harvester with Varying Cross-Sectional Area

Directory of Open Access Journals (Sweden)

Maiara Rosa

2014-01-01

Full Text Available This paper reports on the modeling and on the experimental verification of electromechanically coupled beams with varying cross-sectional area for piezoelectric energy harvesting. The governing equations are formulated using the Rayleigh-Ritz method and Euler-Bernoulli assumptions. A load resistance is considered in the electrical domain for the estimate of the electric power output of each geometric configuration. The model is first verified against the analytical results for a rectangular bimorph with tip mass reported in the literature. The experimental verification of the model is also reported for a tapered bimorph cantilever with tip mass. The effects of varying cross-sectional area and tip mass on the electromechanical behavior of piezoelectric energy harvesters are also discussed. An issue related to the estimation of the optimal load resistance (that gives the maximum power output on beam shape optimization problems is also discussed.

Cross section of W and Z inclusive production and the W/Z cross section ratio in association with one jet for the boson decaying into electron(s) with ATLAS 7 TeV data

CERN Document Server

Berglund, Elina

2011-01-01

This thesis investigates the inclusive production cross section of W and Z bosons as well as their ratio in association with one jet. The cross sections are estimated with 7 TeV LHC proton-proton collision data, collected by ATLAS during 2010, resulting in an integrated luminosity of approximately 40 pb−1 . This thesis focuses on the analysis performed in the electron channel, while comparisons with the results obtained in the muon channel also are included. This is the first time the W and Z production cross sections are measured at this center-of-mass energy and the results are important for various reasons, such as testing perturbative theoretical calculations and understanding these signatures as backgrounds to other physics processes. The final inclusive cross section values obtained in the electron channel are the following: σ(W → eν ) = 10.255 ± 0.031(stat) ± 0.190(syst) ± 0.349(lumi) ± 0.156(acc) nb σ(Z → ee) = 0.952 ± 0.010(stat) ± 0.026(syst) ± 0.032(lumi) ± 0.019(acc) nb The res...

Modelisation of the fission cross section

International Nuclear Information System (INIS)

Morariu, Claudia

2013-03-01

The neutron cross sections of four nuclear systems (n+ 235 U, n+ 233 U, n+ 241 Am and n+ 237 Np) are studied in the present document. The target nuclei of the first case, like 235 U and 239 Pu, have a large fission cross section after the absorption of thermal neutrons. These nuclei are called 'fissile' nuclei. The other type of nuclei, like 237 Np and 241 Am, fission mostly with fast neutrons, which exceed the fission threshold energy. These types of nuclei are called 'fertile'. The compound nuclei of the fertile nuclei have a binding energy higher than the fission barrier, while for the fissile nuclei the binding energy is lower than the fission barrier. In this work, the neutron induced cross sections for both types of nuclei are evaluated in the fast energy range. The total, reaction and shape-elastic cross sections are calculated by the coupled channel method of the optical model code ECIS, while the compound nucleus mechanism are treated by the statistical models implemented in the codes STATIS, GNASH and TALYS. The STATIS code includes a refined model of the fission process. Results from the theoretical calculations are compared with data retrieved from the experimental data base EXFOR. (author) [fr

Cross sections for hadron and lepton production processes

International Nuclear Information System (INIS)

Bhattacharya, R.

1976-01-01

Charged heavy lepton production in proton-proton collisions is studied. Motivated by recent experimental results from the Stanford Linear Accelerator Center a parton model analysis is given of the reaction p + p → L + + L - + x → μ +- + e/ -+ / + neutrinos + x. Results are presented for the total cross section and the differential cross sections with respect to the invariant mass squared of the final charged leptons and the transverse momenta of each one of them. The two-photon mechanism for pair production in colliding beam exeriments is considered. Through the use of mapped invariant integration variables, a reliable exact numerical calculation of the cross section for the production of muon and pion pairs by the two-photon mechanism is provided. Results are given for the exact total cross sections and also the differential cross sections with respect to the invariant mass squared of the pair. These are compared to the results obtained from the equivalent photon approximation method

Total reaction cross sections and neutron-removal cross sections of neutron-rich light nuclei measured by the COMBAS fragment-separator

Science.gov (United States)

Hue, B. M.; Isataev, T.; Erdemchimeg, B.; Artukh, A. G.; Aznabaev, D.; Davaa, S.; Klygin, S. A.; Kononenko, G. A.; Khuukhenkhuu, G.; Kuterbekov, K.; Lukyanov, S. M.; Mikhailova, T. I.; Maslov, V. A.; Mendibaev, K.; Sereda, Yu M.; Penionzhkevich, Yu E.; Vorontsov, A. N.

2017-12-01

Preliminary results of measurements of the total reaction cross sections σR and neutron removal cross section σ-xn for weakly bound 6He, 8Li, 9Be and 10Be nuclei at energy range (20-35) A MeV with 28Si target is presented. The secondary beams of light nuclei were produced by bombardment of the 22Ne (35 A MeV) primary beam on Be target and separated by COMBAS fragment-separator. In dispersive focal plane a horizontal slit defined the momentum acceptance as 1% and a wedge degrader of 200 μm Al was installed. The Bρ of the second section of the fragment-separator was adjusted for measurements in energy range (20-35) A MeV. Two-neutron removal cross sections for 6He and 10Be and one -neutron removal cross sections 8Li and 9Be were measured.

Microscopic cross-section measurements by thermal neutron activation

International Nuclear Information System (INIS)

Avila L, J.

1987-08-01

Microscopic cross sections measured by thermal neutron activation using RP-0 reactor at the Peruvian Nuclear Energy Institute. The method consists in measuring microscopic cross section ratios through activated samples, requiring being corrected in thermal and epithermal energetic range by Westcott formalism. Furthermore, the comptage ratios measured for each photopeak to its decay fraction should be normalized from interrelation between both processes above, activation microscopic cross sections are obtained

Distorted eikonal cross sections: A time-dependent view

International Nuclear Information System (INIS)

Turner, R.E.

1982-01-01

For Hamiltonians with two potentials, differential cross sections are written as time-correlation functions of reference and distorted transition operators. Distorted eikonal differential cross sections are defined in terms of straight-line and reference classical trajectories. Both elastic and inelastic results are obtained. Expressions for the inelastic cross sections are presented in terms of time-ordered cosine and sine memory functions through the use of the Zwanzig-Feshbach projection-operator method

Discussion of electron cross sections for transport calculations

International Nuclear Information System (INIS)

Berger, M.J.

1983-01-01

This paper deals with selected aspects of the cross sections needed as input for transport calculations and for the modeling of radiation effects in biological materials. Attention is centered mainly on the cross sections for inelastic interactions between electrons and water molecules and the use of these cross sections for the calculation of energy degradation spectra and of ionization and excitation yields. 40 references, 3 figures, 1 table

Symmetric charge transfer cross section of uranium

International Nuclear Information System (INIS)

Shibata, Takemasa; Ogura, Koichi

1995-03-01

Symmetric charge transfer cross section of uranium was calculated under consideration of reaction paths. In the charge transfer reaction a d 3/2 electron in the U atom transfers into the d-electron site of U + ( 4 I 9/2 ) ion. The J value of the U atom produced after the reaction is 6, 5, 4 or 3, at impact energy below several tens eV, only resonant charge transfer in which the product atom is ground state (J=6) takes place. Therefore, the cross section is very small (4-5 x 10 -15 cm 2 ) compared with that considered so far. In the energy range of 100-1000eV the cross section increases with the impact energy because near resonant charge transfer in which an s-electron in the U atom transfers into the d-electron site of U + ion. Charge transfer cross section between U + in the first excited state (289 cm -1 ) and U in the ground state was also obtained. (author)

NNLO jet cross sections by subtraction

Energy Technology Data Exchange (ETDEWEB)

Somogyi, G.; Bolzoni, P. [DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Trocsanyi, Z. [CERN PH-TH, on leave from University of Debrecen and Institute of Nuclear Research of HAS, H-4001 P.O.Box 51 (Hungary)

2010-08-15

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of the NNLO subtraction scheme of Refs. [G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 06, 024 (2005), (arXiv:hep-ph/0502226); G. Somogyi and Z. Trocsanyi, (2006), (arXiv:hep-ph/0609041); G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 01, 070 (2007), (arXiv:hep-ph/0609042); G. Somogyi and Z. Trocsanyi, JHEP 01, 052 (2007), (arXiv:hep-ph/0609043)] over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state.

NNLO jet cross sections by subtraction

International Nuclear Information System (INIS)

Somogyi, G.; Bolzoni, P.; Trocsanyi, Z.

2010-01-01

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of the NNLO subtraction scheme of Refs. [G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 06, 024 (2005), (arXiv:hep-ph/0502226); G. Somogyi and Z. Trocsanyi, (2006), (arXiv:hep-ph/0609041); G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 01, 070 (2007), (arXiv:hep-ph/0609042); G. Somogyi and Z. Trocsanyi, JHEP 01, 052 (2007), (arXiv:hep-ph/0609043)] over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state.

Extensive set of low-fidelity cross sections covariances in fast neutron region

International Nuclear Information System (INIS)

Pigni, M.T.; Herman, M.; Oblozinsky, P.

2008-01-01

We produced a large set of neutron cross section covariances in the energy range of 5 keV - 20 MeV. The covariance matrices were calculated for 307 isotopes divided into three major regions: structural materials, fission products, and heavy nuclei. These results have been developed to provide initial, but consistent estimates of covariance data for nuclear criticality safety applications. The methodology for the determination of such covariance matrices is presented. It combines the nuclear reaction model code EMPIRE which calculates sensitivity of cross sections to nuclear reaction model parameters, and the Bayesian code KALMAN that propagates uncertainties of the model parameters to cross sections. Taking into account large number of materials, only marginal reference to experimental data was made. The covariances were derived from the perturbation of several key model parameters selected by the sensitivity analysis. These parameters refer to the optical model potential, the level densities and the strength of the pre-equilibrium emission. This work represents the first try ever to generate nuclear data covariances on such a large scale. (authors)

FENDL/E. Evaluated nuclear data library of neutron nuclear interaction cross-sections and photon production cross-sections and photon-atom interaction cross sections for fusion applications. Version 1.1 of November 1994

International Nuclear Information System (INIS)

Pashchenko, A.B.; Wienke, H.; Ganesan, S.; McLaughlin, P.K.

1996-01-01

This document presents the description of a physical tape containing the basic evaluated nuclear data library of neutron nuclear interaction cross-sections and photon production cross-sections and photon-atom interaction cross-sections for fusion applications. It is part of FENDL, the evaluated nuclear data library for fusion applications. The nuclear data are available cost-free for distribution to interested scientists upon request. The data can also be retrieved by the user via online access through international computer networks. (author). 11 refs, 1 tab

Average cross sections for the 252Cf neutron spectrum

International Nuclear Information System (INIS)

Dezso, Z.; Csikai, J.

1977-01-01

A number of average cross sections have been measured for 252 Cf neutrons in (n, γ), (n,p), (n,2n), (n,α) reactions by the activation method and for fission by fission chamber. Cross sections have been determined for 19 elements and 45 reactions. The (n,γ) cross section values lie in the interval from 0.3 to 200 mb. The data as a function of target neutron number increases up to about N=60 with minimum near to dosed shells. The values lie between 0.3 mb and 113 mb. These cross sections decrease significantly with increasing the threshold energy. The values are below 20 mb. The data do not exceed 10 mb. Average (n,p) cross sections as a function of the threshold energy and average fission cross sections as a function of Zsup(4/3)/A are shown. The results obtained are summarized in tables

Measurements of the total neutron cross-sections of poly- and mono-germanium crystals at neutron energies below 1 eV

International Nuclear Information System (INIS)

Maayouf, R.M.A.; Abdel-Kawy, A.; Abbas, Y.; Habib, N.; Adib, M.; Hamouda, I.

1983-12-01

Total neutron cross-section measurements have been performed for poly and mono-germanium crystals in the energy range from 2 meV-1eV. The measurements were performed using two TOF and a double axis crystal spectrometer installed at the ET-RR-1 reactor. The obtained neutron cross-sections were analyzed using the single level Breit-Wigner formula. The coherent scattering amplitude was determined from the Bragg reflections observed in the total neutron cross-section of Ge and the analysis of its neutron diffraction pattern. The incoherent and thermal diffuse scattering cross-sections of Ge were estimated from the analysis of the total cross-section data obtained for Ge mono-crystal

Measurement of the thorium absorption cross section shape near thermal energy (LWBR development program)

International Nuclear Information System (INIS)

Green, L.

1976-11-01

The shape of the thorium absorption cross section near thermal energies was investigated. This shape is dominated by one or more negative energy resonances whose parameters are not directly known, but must be inferred from higher energy data. Since the integral quantity most conveniently describing the thermal cross section shape is the Westcottg-factor, effort was directed toward establishing this quantity to high precision. Three nearly independent g-factor estimates were obtained from measurements on a variety of foils in three different neutron spectra provided by polyethylene-moderated neutrons from a 252 Cf source and from irradiations in the National Bureau of Standards ''Standard Thermal Neutron Density.'' The weighted average of the three measurements was 0.993 +- 0.004. This is in good agreement with two recent evaluations and supports the adequacy of the current cross section descriptions

The effects of workplace flexibility on health behaviors: a cross-sectional and longitudinal analysis.

Science.gov (United States)

Grzywacz, Joseph G; Casey, Patrick R; Jones, Fiona A

2007-12-01

To examine the cross-sectional and longitudinal associations between workplace flexibility and health behaviors, and estimate the potential importance of flexibility for effective worksite health promotion programs. Cross-sectional and longitudinal health risk appraisal data were obtained from US based employees of a multinational pharmaceutical company (n = 3193). Examined health behaviors were hours of sleep, physical activity frequency, health education seminar attendance, frequency of practicing personal resilience techniques, and self-appraised lifestyle. Self-reported flexibility in the workplace was the primary independent variable. Each health behavior, except regular attendance in health education seminars, was positively related to perceived flexibility in cross-sectional analyses. Sleep and self-appraised lifestyle were significantly related to changes in perceived flexibility over time. Workplace flexibility may contribute to positive lifestyle behaviors, and may play an important role in effective worksite health promotion programs.

Cross section library DOSCROS77 (in the SAND-II format)

International Nuclear Information System (INIS)

Zijp, W.L.; Nolthenius, H.J.; Borg, N.J.C.M. van der.

1977-08-01

The dosimetry cross section library DOSCROS77 is documented with tables, plots and cross section values averaged over a few reference spectra. This library is based on the ENDF/B-IV dosimetry file, supplemented with some other evaluations. The total number of reaction cross section sets incorporated in this library is 49 (+3 cover cross sections sets). The cross section data are available in a format which is suitable for the program SAND-II

Full inelastic cross section, effective stopping and ranges of fast multiply charged ions

International Nuclear Information System (INIS)

Alimov, R.A.; Arslanbekov, T.U.; Matveev, B.I.; Rakhmatov, A.S.

1994-01-01

Inelastic processes taking place in collision of fast multiply charged ions with atoms are considered on the base of mechanism of sudden momentum transfer. The simple estimations are proposed of full inelastic cross sections, effective stopping and ion ranges in gaseous medium. (author). 10 refs

First measurement of the Rayleigh cross section

NARCIS (Netherlands)

Naus, H.; Ubachs, W.

2000-01-01

Rayleigh cross section for N2, Ar and SF6 was performed using the technique of cavity ring-down spectroscopy (CRDS). The experiment was based on the assumption that scattering cross section is equal to the extinction in the absence of absorption. The theory explains the molecular origin of

JSD1000: multi-group cross section sets for shielding materials

International Nuclear Information System (INIS)

Yamano, Naoki

1984-03-01

A multi-group cross section library for shielding safety analysis has been produced by using ENDF/B-IV. The library consists of ultra-fine group cross sections, fine-group cross sections, secondary gamma-ray production cross sections and effective macroscopic cross sections for typical shielding materials. Temperature dependent data at 300, 560 and 900 K have been also provided. Angular distributions of the group to group transfer cross section are defined by a new method of ''Direct Angular Representation'' (DAR) instead of the method of finite Legendre expansion. The library designated JSD1000 are stored in a direct access data base named DATA-POOL and data manipulations are available by using the DATA-POOL access package. The 3824 neutron group data of the ultra-fine group cross sections and the 100 neutron, 20 photon group cross sections are applicable to shielding safety analyses of nuclear facilities. This report provides detailed specifications and the access method for the JSD1000 library. (author)

Cross-sectional investigation of HEMS activities in Europe

DEFF Research Database (Denmark)

Di Bartolomeo, Stefano; Gava, Paolo; Truhlář, Anatolij

2014-01-01

OBJECTIVES: To gather information on helicopter emergency medical services (HEMSs) activities across Europe. METHODS: Cross-sectional data-collection on daily (15 November 2013) activities of a sample of European HEMSs. A web-based questionnaire with both open and closed questions was used......, by paramedics in 24%, and by nurses in 9%. On-board physicians estimated to have caused a major decrease of death risk in 47% of missions, possible decrease in 22%, minor benefit in 17%, no benefit in 11%, and damage in 3%. Earlier treatment and faster transport to hospital were the main reasons for benefit...

Parameterized representation of macroscopic cross section for PWR reactor

International Nuclear Information System (INIS)

Fiel, João Cláudio Batista; Carvalho da Silva, Fernando; Senra Martinez, Aquilino; Leal, Luiz C.

2015-01-01

Highlights: • This work describes a parameterized representation of the homogenized macroscopic cross section for PWR reactor. • Parameterization enables a quick determination of problem-dependent cross-sections to be used in few group calculations. • This work allows generating group cross-section data to perform PWR core calculations without computer code calculations. - Abstract: The purpose of this work is to describe, by means of Chebyshev polynomials, a parameterized representation of the homogenized macroscopic cross section for PWR fuel element as a function of soluble boron concentration, moderator temperature, fuel temperature, moderator density and 235 92 U enrichment. The cross-section data analyzed are fission, scattering, total, transport, absorption and capture. The parameterization enables a quick and easy determination of problem-dependent cross-sections to be used in few group calculations. The methodology presented in this paper will allow generation of group cross-section data from stored polynomials to perform PWR core calculations without the need to generate them based on computer code calculations using standard steps. The results obtained by the proposed methodology when compared with results from the SCALE code calculations show very good agreement

The total collision cross section in the glory region

International Nuclear Information System (INIS)

Biesen, J.J.H. van den.

1982-01-01

Chapter 1 presents a calculation of approximate total cross sections in the glory region from noble gas potentials. The relations between the main features of the total cross section and the properties of the potential to which these are sensitive are extensively investigated in chapter II. A beam apparatus has been developed, which allows for accurate measurements on the total cross section. All effects due to the finite angular and velocity resolution of the apparatus can be eliminated from the data to yield actual total cross sections as a function of the relative velocity. This facilitates a comparison to total cross sections predicted by potentials available in the literature. A brief description of the apparatus and of the data reduction is given in chapter III. The total cross section data obtained for various noble gas combinations are presented and analysed in chapter IV, where also a large number of potentials proposed in the literature is tested. In chapter V the quenching of the glories in the case of a non-spherical interaction is analysed. Subsequently, total cross section data for some atom-molecule systems are discussed. (Auth.)

A measurement of the Z cross-section at LHCb

CERN Document Server

Keaveney, James Michael

2011-01-01

The LHCb experiment, one of the four main experiments at the Large Hadron Collider, recorded 37.66 pb$^{-1}$ of 7 TeV proton collision data in 2010. In this thesis, the total cross section and the differential cross section as a function of boson rapidity of the Z $\\to \\mu^+ \\mu^-$ process are measured using 16.5 pb$^{-1}$ of this data. The precise testing of the Standard Model and reduction of uncertainty on Parton Distribution Functions constitute the primary motivations of these measurements. A scheme to select Z $\\to \\mu^+ \\mu^-$ decays has been developed and was justified using simulation. The application of this scheme to the data yielded 830 candidates for the signal process. The events were used to estimate tracking, muon identification and trigger efficiencies with an overall efficiency of 0.71 $\\pm$ 0.04. Three main background sources have been identified: the semi-leptonic decays of beauty and charm quarks, the Z $\\to \\tau^+ \\tau^-$ process where both tau leptons decay to muons and the mis-identifi...

Hardon cross sections at ultra high energies

International Nuclear Information System (INIS)

Yodh, G.B.

1987-01-01

A review of results on total hadronic cross sections at ultra high energies obtained from a study of longitudinal development of cosmic ray air showers is given. The experimental observations show that proton-air inelastic cross section increases from 275 mb to over 500 mb as the collision energy in the center of mass increases from 20 GeV to 20 TeV. The proton-air inelastic cross section, obtained from cosmic ray data at √s = 30 TeV, is compared with calculations using various different models for the energy variation of the parameters of the elementary proton-proton interaction. Three conclusions are derived

Derived Born cross sections of e+e‑ annihilation into open charm mesons from CLEO-c measurements

Science.gov (United States)

Dong, Xiang-Kun; Wang, Liang-Liang; Yuan, Chang-Zheng

2018-04-01

The exclusive Born cross sections of the production of D0, D+ and {{{D}}}{{s}}{{+}} mesons in e+e‑ annihilation at 13 energy points between 3.970 and 4.260 GeV are obtained by applying corrections for initial state radiation and vacuum polarization to the observed cross sections measured by the CLEO-c experiment. Both the statistical and the systematic uncertainties for the obtained Born cross sections are estimated. Supported in part by National Natural Science Foundation of China (NSFC) (11235011, 11475187, 11521505, U1632106), the Ministry of Science and Technology of China (2015CB856701), Key Research Program of Frontier Sciences, CAS, (QYZDJ-SSW-SLH011) and the CAS Center for Excellence in Particle Physics (CCEPP)

Updated Higgs cross section at approximate N{sup 3}LO

Energy Technology Data Exchange (ETDEWEB)

Bonvini, Marco [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ball, Richard D. [Edinburgh Univ. (United Kingdom). Tait Inst.; Forte, Stefano [Milano Univ. (Italy). Dipt. di Fisica; INFN, Milano (Italy); Marzani, Simone [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Ridolfi, Giovanni [Genova Univ. (Italy). Dipt. di Fisica; INFN, Genova (Italy)

2014-04-15

We update our estimate of the cross section for Higgs production in gluon fusion at next-to-next-to-next-to-leading order (N{sup 3}LO) in α{sub s} in view of the recent full computation of the result in the soft limit for infinite top mass, which determines a previously unknown constant. We briefly discuss the phenomenological implications. Results are available through the updated version of the ggHiggs code.

Total cross section results for deuterium electrodisintegration

International Nuclear Information System (INIS)

Skopik, D.M.; Murphy, J.J. II; Shin, Y.M.

1976-01-01

Theoretical total cross sections for deuterium electrodisintegration are presented as a function of incident electron energy. The cross section has been calculated using virtual photon theory with Partovi's photodisintegration calculation for E/subx/ > 10 MeV and effective range theory for E/subx/ 2 H(e, n) reaction in Tokamak reactors

Measurement cross sections for radioisotopes production

International Nuclear Information System (INIS)

Garrido, E.

2011-01-01

New radioactive isotopes for nuclear medicine can be produced using particle accelerators. This is one goal of Arronax, a high energy - 70 MeV - high intensity - 2*350 μA - cyclotron set up in Nantes. A priority list was established containing β - - 47 Sc, 67 Cu - β + - 44 Sc, 64 Cu, 82 Sr/ 82 Rb, 68 Ge/ 68 Ga - and α emitters - 211 At. Among these radioisotopes, the Scandium 47 and the Copper 67 have a strong interest in targeted therapy. The optimization of their productions required a good knowledge of their cross-sections but also of all the contaminants created during irradiation. We launched on Arronax a program to measure these production cross-sections using the Stacked-Foils' technique. It consists in irradiating several groups of foils - target, monitor and degrader foils - and in measuring the produced isotopes by γ-spectrometry. The monitor - nat Cu or nat Ni - is used to correct beam loss whereas degrader foils are used to lower beam energy. We chose to study the nat Ti(p,X) 47 Sc and 68 Zn(p,2p) 67 Cu reactions. Targets are respectively natural Titanium foil - bought from Goodfellow - and enriched Zinc 68 deposited on Silver. In the latter case, Zn targets were prepared in-house - electroplating of 68 Zn - and a chemical separation between Copper and Gallium isotopes has to be made before γ counting. Cross-section values for more than 40 different reactions cross-sections have been obtained from 18 MeV to 68 MeV. A comparison with the Talys code is systematically done. Several parameters of theoretical models have been studied and we found that is not possible to reproduce faithfully all the cross-sections with a given set of parameters. (author)

Neutron, Proton, and Photonuclear Cross Sections for Radiation Therapy and Radiation Protection

International Nuclear Information System (INIS)

Chadwick, M.B.

1998-01-01

The authors review recent work at Los Alamos to evaluate neutron, proton, and photonuclear cross section up to 150 MeV (to 250 MeV for protons), based on experimental data and nuclear model calculations. These data are represented in the ENDF format and can be used in computer codes to simulate radiation transport. They permit calculations of absorbed dose in the body from therapy beams, and through use of kerma coefficients allow absorbed dose to be estimated for a given neutron energy distribution. For radiation protection, these data can be used to determine shielding requirements in accelerator environments, and to calculate neutron, proton, gamma-ray, and radionuclide production. Illustrative comparisons of the evaluated cross section and kerma coefficient data with measurements are given

Neutron cross section libraries for analysis of fusion neutronics experiments

International Nuclear Information System (INIS)

Kosako, Kazuaki; Oyama, Yukio; Maekawa, Hiroshi; Nakamura, Tomoo

1988-03-01

We have prepared two computer code systems producing neutron cross section libraries to analyse fusion neutronics experiments. First system produces the neutron cross section library in ANISN format, i.e., the multi-group constants in group independent format. This library can be obtained by using the multi-group constant processing code system MACS-N and the ANISN format cross section compiling code CROKAS. Second system is for the continuous energy cross section library for the MCNP code. This library can be obtained by the nuclear data processing system NJOY which generates pointwise energy cross sections and the cross section compiling code MACROS for the MCNP library. In this report, we describe the production procedures for both types of the cross section libraries, and show six libraries with different conditions in ANISN format and a library for the MCNP code. (author)

Temperature-dependent absorption cross sections for hydrogen peroxide vapor

Science.gov (United States)

Nicovich, J. M.; Wine, P. H.

1988-01-01

Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

Multivariate survivorship analysis using two cross-sectional samples.

Science.gov (United States)

Hill, M E

1999-11-01

As an alternative to survival analysis with longitudinal data, I introduce a method that can be applied when one observes the same cohort in two cross-sectional samples collected at different points in time. The method allows for the estimation of log-probability survivorship models that estimate the influence of multiple time-invariant factors on survival over a time interval separating two samples. This approach can be used whenever the survival process can be adequately conceptualized as an irreversible single-decrement process (e.g., mortality, the transition to first marriage among a cohort of never-married individuals). Using data from the Integrated Public Use Microdata Series (Ruggles and Sobek 1997), I illustrate the multivariate method through an investigation of the effects of race, parity, and educational attainment on the survival of older women in the United States.

Validation of evaluated neutron standard cross sections

International Nuclear Information System (INIS)

Badikov, S.; Golashvili, T.

2008-01-01

Some steps of the validation and verification of the new version of the evaluated neutron standard cross sections were carried out. In particular: -) the evaluated covariance data was checked for physical consistency, -) energy-dependent evaluated cross-sections were tested in most important neutron benchmark field - 252 Cf spontaneous fission neutron field, -) a procedure of folding differential standard neutron data in group representation for preparation of specialized libraries of the neutron standards was verified. The results of the validation and verification of the neutron standards can be summarized as follows: a) the covariance data of the evaluated neutron standards is physically consistent since all the covariance matrices of the evaluated cross sections are positive definite, b) the 252 Cf spectrum averaged standard cross-sections are in agreement with the evaluated integral data (except for 197 Au(n,γ) reaction), c) a procedure of folding differential standard neutron data in group representation was tested, as a result a specialized library of neutron standards in the ABBN 28-group structure was prepared for use in reactor applications. (authors)

View-CXS neutron and photon cross-sections viewer

International Nuclear Information System (INIS)

Subbaiah, K.V.; Sunil Sunny, C.

2004-01-01

A graphical user-friendly interface is developed in Visual Basic (VB)-6 to view the variation of neutron and photon interaction cross-sections of different isotopes as a function of energy. VB subroutines developed read the binary data files of cross-sections created in MCNP-ACE (Briesmeister, J.F., 1993. MCNP - a general purpose Monte Carlo N-Particle Transport code. Version 4A. LANL, USA), ANISN-DLC (Engle W.W. Jr., 1967, A User's Manual for ANISN, K-1693; ORNL, 1974. 100 group neutron cross section data based on ENDF/B-III. Oak Ridge National Laboratory, USA) and KENO-AMPX (Petrie, L.M., Landers, N.F., 1984 KENO-Va- An Improved Monte Carlo Criticality Program with Super Grouping. RSICC-CCC-548, USA) formats using LAHEY-77 Fortran Compiler. The information on isotopes present in each library will be displayed with the help of database files prepared using Micro-Soft ACESS. The cross-section data can be viewed in different presentation styles namely, line graphs, bar graphs, histograms etc., with different color and symbol options. The cross-section plots generated can be saved as Bit-Map file to embed in any other text files. This software enables inter comparison of cross-sections from different type of libraries for isotopes as well as mixtures. Provision is made to view the cross-sections for nuclear reactions such as (n,γ), (n,f), (n,α), etc. The software can be obtained from Radiation Safety Information and Computational Centre (RSICC), ORNL, USA with the code package identification number PSR-514. The software package needs a hard disk space of about 80 MB when installed and works in WINDOWS-95/98/2000 operating systems

Optical Model and Cross Section Uncertainties

Energy Technology Data Exchange (ETDEWEB)

Herman,M.W.; Pigni, M.T.; Dietrich, F.S.; Oblozinsky, P.

2009-10-05

Distinct minima and maxima in the neutron total cross section uncertainties were observed in model calculations using spherical optical potential. We found this oscillating structure to be a general feature of quantum mechanical wave scattering. Specifically, we analyzed neutron interaction with 56Fe from 1 keV up to 65 MeV, and investigated physical origin of the minima.We discuss their potential importance for practical applications as well as the implications for the uncertainties in total and absorption cross sections.

Pion-nucleus cross sections

International Nuclear Information System (INIS)

Barashenkov, V.S.

1990-01-01

The tables of inelastic and total cross sections of π ± mesons interactions with nuclei 4 He- 238 U are presented. The tables are obtained by theoretical analysis of known experimental data for energies higher some tens of MeV. 1 ref.; 1 tab

Proton-air and proton-proton cross sections

Directory of Open Access Journals (Sweden)

Ulrich Ralf

2013-06-01

Full Text Available Different attempts to measure hadronic cross sections with cosmic ray data are reviewed. The major results are compared to each other and the differences in the corresponding analyses are discussed. Besides some important differences, it is crucial to see that all analyses are based on the same fundamental relation of longitudinal air shower development to the observed fluctuation of experimental observables. Furthermore, the relation of the measured proton-air to the more fundamental proton-proton cross section is discussed. The current global picture combines hadronic proton-proton cross section data from accelerator and cosmic ray measurements and indicates a good consistency with predictions of models up to the highest energies.

Fission-neutron displacement cross sections in metals

International Nuclear Information System (INIS)

Takamura, Saburo; Aruga, Takeo; Nakata, Kiyotomo

1985-01-01

The sensitivity damage rates for 22 metals were measured after fission-spectrum neutron irradiation at low temperature and the experimental damage rates were compared with the theoretical calculation. The relation between the theoretical displacement cross section and the atomic weight of metals can be written by two curves; one is for fcc and hcp metals, and another is for bcc metals. On the other hand, the experimental displacement cross section versus atomic weight is shown approximately by a curve for both fcc and bcc metals, and the cross section for hcp metals deviates from the curve. The defect production efficiency is 0.3-0.4 for fcc metals and 0.6-0.8 for bcc metals. (orig.)

Compact fitting formulas for electron-impact cross sections

International Nuclear Information System (INIS)

Kim, Y.K.

1992-01-01

Compact fitting formulas, which contain four fitting constants, are presented for electron-impact excitation and ionization cross sections of atoms and ions. These formulas can fit experimental and theoretical cross sections remarkably well, when resonant structures are smoothed out, from threshold to high incident electron energies (<10 keV), beyond which relativistic formulas are more appropriate. Examples of fitted cross sections for some atoms and ions are presented. The basic form of the formula is valid for both atoms and molecules

Single-level resonance parameters fit nuclear cross-sections

Science.gov (United States)

Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

1970-01-01

Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

Analytical formulas for calculation of K X-ray production cross sections by alpha ions

International Nuclear Information System (INIS)

Abdellatif, A.; Kahoul, A.; Deghfel, B.; Nekkab, M.; Medjadi, D.E.

2012-01-01

In the present study, different procedures are followed to deduce the semi-empirical and the empirical K X-rayX-ray production cross sections induced by alpha ions from the available experimental data and the theoretical results of the ECPSSR model for elements with 20≤Z≤30. The deduced K X-ray production cross sections are compared with predictions from ECPSSR model and with other earlier works. Generally, the deduced K X-ray production cross sections obtained by fitting the available experimental data for each element separately give the most reliable values than those obtained by a global fit. - Highlights: ► The results were presented for elements with atomic numbers 20≤Z≤30 by alpha impact. ► The present semi-empirical formulas were derived from both theoretical and experimental values. ► The available experimental data are directly fitted to deduce the empirical one. ► The results obtained for each element separately give the most reliable values than those obtained by a global fit. ► This procedure is proposed as a black-box way to quickly estimate the cross section.

Total cross section of highly excited strings

International Nuclear Information System (INIS)

Lizzi, F.; Senda, I.

1990-01-01

The unpolarized total cross section for the joining of two highly excited strings is calculated. The calculation is performed by taking the average overall states in the given excitation levels of the initial strings. We find that the total cross section grows with the energy and momentum of the initial states. (author). 8 refs, 1 fig

MXS cross-section preprocessor user's manual

International Nuclear Information System (INIS)

Parker, F.; Ishikawa, M.; Luck, L.

1987-03-01

The MXS preprocessor has been designed to reduce the execution time of programs using isotopic cross-section data and to both reduce the execution time and improve the accuracy of shielding-factor interpolation in the SIMMER-II accident analysis program. MXS is a dual-purpose preprocessing code to: (1) mix isotopes into materials and (2) fit analytic functions to the shelf-shielding data. The program uses the isotope microscopic neutron cross-section data from the CCCC standard interface file ISOTXS and the isotope Bondarenko self-shielding data from the CCCC standard interface file BRKOXS to generate cross-section and self-shielding data for materials. The materials may be a mixture of several isotopes. The self-shielding data for the materials may be the actual shielding factors or a set of coefficients for functions representing the background dependence of the shielding factors. A set of additional data is given to describe the functions necessary to interpolate the shielding factors over temperature

Neutron capture cross sections of Kr

Directory of Open Access Journals (Sweden)

Fiebiger Stefan

2017-01-01

Full Text Available Neutron capture and β− -decay are competing branches of the s-process nucleosynthesis path at 85Kr [1], which makes it an important branching point. The knowledge of its neutron capture cross section is therefore essential to constrain stellar models of nucleosynthesis. Despite its importance for different fields, no direct measurement of the cross section of 85Kr in the keV-regime has been performed. The currently reported uncertainties are still in the order of 50% [2, 3]. Neutron capture cross section measurements on a 4% enriched 85Kr gas enclosed in a stainless steel cylinder were performed at Los Alamos National Laboratory (LANL using the Detector for Advanced Neutron Capture Experiments (DANCE. 85Kr is radioactive isotope with a half life of 10.8 years. As this was a low-enrichment sample, the main contaminants, the stable krypton isotopes 83Kr and 86Kr, were also investigated. The material was highly enriched and contained in pressurized stainless steel spheres.

NNLO jet cross sections by subtraction

Science.gov (United States)

Somogyi, G.; Bolzoni, P.; Trócsányi, Z.

2010-08-01

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of the NNLO subtraction scheme of Refs. [G. Somogyi, Z. Trócsányi, and V. Del Duca, JHEP 06, 024 (2005), arXiv:hep-ph/0502226; G. Somogyi and Z. Trócsányi, (2006), arXiv:hep-ph/0609041; G. Somogyi, Z. Trócsányi, and V. Del Duca, JHEP 01, 070 (2007), arXiv:hep-ph/0609042; G. Somogyi and Z. Trócsányi, JHEP 01, 052 (2007), arXiv:hep-ph/0609043] over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state.

Limit Theory for Panel Data Models with Cross Sectional Dependence and Sequential Exogeneity.

Science.gov (United States)

Kuersteiner, Guido M; Prucha, Ingmar R

2013-06-01

The paper derives a general Central Limit Theorem (CLT) and asymptotic distributions for sample moments related to panel data models with large n . The results allow for the data to be cross sectionally dependent, while at the same time allowing the regressors to be only sequentially rather than strictly exogenous. The setup is sufficiently general to accommodate situations where cross sectional dependence stems from spatial interactions and/or from the presence of common factors. The latter leads to the need for random norming. The limit theorem for sample moments is derived by showing that the moment conditions can be recast such that a martingale difference array central limit theorem can be applied. We prove such a central limit theorem by first extending results for stable convergence in Hall and Hedye (1980) to non-nested martingale arrays relevant for our applications. We illustrate our result by establishing a generalized estimation theory for GMM estimators of a fixed effect panel model without imposing i.i.d. or strict exogeneity conditions. We also discuss a class of Maximum Likelihood (ML) estimators that can be analyzed using our CLT.

ISSUES IN NEUTRON CROSS SECTION COVARIANCES

Energy Technology Data Exchange (ETDEWEB)

Mattoon, C.M.; Oblozinsky,P.

2010-04-30

We review neutron cross section covariances in both the resonance and fast neutron regions with the goal to identify existing issues in evaluation methods and their impact on covariances. We also outline ideas for suitable covariance quality assurance procedures.We show that the topic of covariance data remains controversial, the evaluation methodologies are not fully established and covariances produced by different approaches have unacceptable spread. The main controversy is in very low uncertainties generated by rigorous evaluation methods and much larger uncertainties based on simple estimates from experimental data. Since the evaluators tend to trust the former, while the users tend to trust the latter, this controversy has considerable practical implications. Dedicated effort is needed to arrive at covariance evaluation methods that would resolve this issue and produce results accepted internationally both by evaluators and users.

Study of the elastic scattering differential cross sections of a proton beam by a cesium target

International Nuclear Information System (INIS)

El Maddarsi, Mohamed.

1978-01-01

The elastic differential cross section of H + on Cs is studied experimentally and theoretically. The experimental device is described, after which the differential cross-section values obtained as a function of the laboratory angle are given for four incident energies: 13.4 eV, 15.1 eV, 17.7 eV and 24.2 eV. By means of an interaction potential of the quasi-molecule H + Cs the differential cross sections are calculated for the same incident energies; this calculation uses the semi-classical method of stationary phases which shows clearly the limits of conventional description and the changes introduced by quantum effects. Very good agreement is obtained between theoretical and experimental results, which shows that elastic scattering is very little perturbed by inelastic channels in this energy range. The estimated inelastic cross section at 24 eV is about 1.9 10 -15 cm 2 , corresponding to 1.6% of the scattering process [fr

Mid-IR Absorption Cross-Section Measurements of Hydrocarbons

KAUST Repository

Alrefae, Majed Abdullah

2013-01-01

-known at combustion-relevant conditions. Absorption cross-section is an important spectroscopic quantity and has direct relation to the species concentration. In this work, the absorption cross-sections of basic hydrocarbons are measured using Fourier Transform

LHCb cross-section measurements with heavy flavour jets

CERN Multimedia

Michielin, Emanuele

2017-01-01

Cross-section measurements of jets originating from the hadronization of beauty ($b$) and charm ($c$) quarks at LHCb give the unique opportunity to probe Parton Distribution Functions (PDFs) at low and large momentum fraction and to test the Standard Model in the forward region. In this poster the production of $t\\bar{t}$ pairs in the forward region, the measurement of the $W+b\\bar{b}$ and $W+c\\bar{c}$ cross-section and the measurement of the $Z\\rightarrow b\\bar{b}$ cross-section are presented.

Tandem-method for measurement of destruction cross-sections of neutral projectiles at intermediate and high velocities

International Nuclear Information System (INIS)

Sant'Anna, M.M.; Magnani, B.F.; Correa, R.S.; Coelho, L.F.S.

2007-01-01

We have recently presented destruction cross-section data for negative ions obtained with a technique that uses the gas stripper of a tandem accelerator as the collision target. In this work, we develop an extension of that technique to measure destruction cross-sections for neutral projectiles, important parameters to estimate neutral beam attenuation in Heavy Ion Fusion applications. Measurements for the H+N 2 collision system are used to exemplify and discuss the capabilities and limitations of the proposed experimental method

Investigation of magnon dispersion relations and neutron scattering cross sections with special attention to anisotropy effects

DEFF Research Database (Denmark)

Lindgård, Per-Anker; Kowalska, A.; Laut, Peter

1967-01-01

curves are suggested. The magnon cross section for unpolarized neutrons is calculated and shown to be dependent on the anisotropy in the spin interaction. Thus in principle it allows the detection of anisotropy in the exchange interaction. Some remarks are made concerning antiferromagnetic and plane...... for the exchange interaction seem to be necessary for agreement with experimental dispersion curves be obtained. The effect of the anisotropy in the cross section is estimated and shown to be important for small magnon energies....

Neutron cross section measurements for the Fast Breeder Program

International Nuclear Information System (INIS)

Block, R.C.

1979-06-01

This research was concerned with the measurement of neutron cross sections of importance to the Fast Breeder Reactor. The capture and total cross sections of fission products ( 101 102 104 Ru, 143 145 Nd, 149 Sm, 95 97 Mo, Cs, Pr, Pd, 107 Pd, 99 Tc) and tag gases (Kr, 78 80 Kr) were measured up to 100 keV. Filtered neutron beams were used to measure the capture cross section of 238 U (with an Fe filter) and the total cross section of Na (with a Na filter). A radioactive neutron capture detector was developed. A list of publications is included

Influence of the Coulomb interaction in the final state on the cross section of single-electron capture by fast ions

International Nuclear Information System (INIS)

Novikov, N.V.; Teplova, Ya.A.

2011-01-01

It is shown that the Coulomb interaction of ions in the final state must be taken into account in the estimation of the cross section of electron capture by fast ions. The cross section of electron capture decreases considerably, and the dependence of the cross section on the collision energy becomes close to the experimental one if the interaction of charged particles after collision is taken into account. -- Highlights: → Coulomb interaction of ions in the final state must be taken into account. → This interaction leads to a considerable decrease in the cross section. → The dependence on energy close to the experimental one.

Developing Scientific Reasoning Through Drawing Cross-Sections

Science.gov (United States)

Hannula, K. A.

2012-12-01

Cross-sections and 3D models of subsurface geology are typically based on incomplete information (whether surface geologic mapping, well logs, or geophysical data). Creating and evaluating those models requires spatial and quantitative thinking skills (including penetrative thinking, understanding of horizontality, mental rotation and animation, and scaling). However, evaluating the reasonableness of a cross-section or 3D structural model also requires consideration of multiple possible geometries and geologic histories. Teaching students to create good models requires application of the scientific methods of the geosciences (such as evaluation of multiple hypotheses and combining evidence from multiple techniques). Teaching these critical thinking skills, especially combined with teaching spatial thinking skills, is challenging. My Structural Geology and Advanced Structural Geology courses have taken two different approaches to developing both the abilities to visualize and to test multiple models. In the final project in Structural Geology (a 3rd year course with a pre-requisite sophomore mapping course), students create a viable cross-section across part of the Wyoming thrust belt by hand, based on a published 1:62,500 geologic map. The cross-section must meet a number of geometric criteria (such as the template constraint), but is not required to balance. Each student tries many potential geometries while trying to find a viable solution. In most cases, the students don't visualize the implications of the geometries that they try, but have to draw them and then erase their work if it does not meet the criteria for validity. The Advanced Structural Geology course used Midland Valley's Move suite to test the cross-sections that they made in Structural Geology, mostly using the flexural slip unfolding algorithm and testing whether the resulting line lengths balanced. In both exercises, students seemed more confident in the quality of their cross-sections when the

Applications of the BEam Cross section Analysis Software (BECAS)

DEFF Research Database (Denmark)

Blasques, José Pedro Albergaria Amaral; Bitsche, Robert; Fedorov, Vladimir

2013-01-01

A newly developed framework is presented for structural design and analysis of long slender beam-like structures, e.g., wind turbine blades. The framework is based on the BEam Cross section Analysis Software – BECAS – a finite element based cross section analysis tool. BECAS is used for the gener......A newly developed framework is presented for structural design and analysis of long slender beam-like structures, e.g., wind turbine blades. The framework is based on the BEam Cross section Analysis Software – BECAS – a finite element based cross section analysis tool. BECAS is used...... for the generation of beam finite element models which correctly account for effects stemming from material anisotropy and inhomogeneity in cross sections of arbitrary geometry. These type of modelling approach allows for an accurate yet computationally inexpensive representation of a general class of three...

Absolute photoionization cross-section of the methyl radical.

Science.gov (United States)

Taatjes, Craig A; Osborn, David L; Selby, Talitha M; Meloni, Giovanni; Fan, Haiyan; Pratt, Stephen T

2008-10-02

The absolute photoionization cross-section of the methyl radical has been measured using two completely independent methods. The CH3 photoionization cross-section was determined relative to that of acetone and methyl vinyl ketone at photon energies of 10.2 and 11.0 eV by using a pulsed laser-photolysis/time-resolved synchrotron photoionization mass spectrometry method. The time-resolved depletion of the acetone or methyl vinyl ketone precursor and the production of methyl radicals following 193 nm photolysis are monitored simultaneously by using time-resolved synchrotron photoionization mass spectrometry. Comparison of the initial methyl signal with the decrease in precursor signal, in combination with previously measured absolute photoionization cross-sections of the precursors, yields the absolute photoionization cross-section of the methyl radical; sigma(CH3)(10.2 eV) = (5.7 +/- 0.9) x 10(-18) cm(2) and sigma(CH3)(11.0 eV) = (6.0 +/- 2.0) x 10(-18) cm(2). The photoionization cross-section for vinyl radical determined by photolysis of methyl vinyl ketone is in good agreement with previous measurements. The methyl radical photoionization cross-section was also independently measured relative to that of the iodine atom by comparison of ionization signals from CH3 and I fragments following 266 nm photolysis of methyl iodide in a molecular-beam ion-imaging apparatus. These measurements gave a cross-section of (5.4 +/- 2.0) x 10(-18) cm(2) at 10.460 eV, (5.5 +/- 2.0) x 10(-18) cm(2) at 10.466 eV, and (4.9 +/- 2.0) x 10(-18) cm(2) at 10.471 eV. The measurements allow relative photoionization efficiency spectra of methyl radical to be placed on an absolute scale and will facilitate quantitative measurements of methyl concentrations by photoionization mass spectrometry.

Cross-section crushing behaviour of hat-sections (Part II: Analytical modelling)

NARCIS (Netherlands)

Hofmeyer, H.

2005-01-01

Hat-sections are often used to experimentally investigate building sheeting subject to a concentrated load and bending. In car doors, hat-sections are used for side-impact protection. Their crushing behaviour can partly be explained by only observing their cross-sectional behaviour [1]. This

Asymptotic behaviour of pion-pion total cross-sections

Energy Technology Data Exchange (ETDEWEB)

Greynat, David [Dipartimento di Scienze Fisiche, Universita di Napoli “Federico II”,Via Cintia, 80126 Napoli (Italy); Rafael, Eduardo de [Aix-Marseille Université, CNRS,CPT, UMR 7332, 13288 Marseille (France); Université de Toulon, CNRS,CPT, UMR 7332, 83957 La Garde (France); Vulvert, Grégory [Departament de Física Teórica, IFIC,CSIC - Universitat de València, Apt. Correus 22085, E-46071 València (Spain)

2014-03-24

We derive a sum rule which shows that the Froissart-Martin bound for the asymptotic behaviour of the ππ total cross sections at high energies, if modulated by the Lukaszuk-Martin coefficient of the leading log{sup 2} s behaviour, cannot be an optimal bound in QCD. We next compute the total cross sections for π{sup +}π{sup −}, π{sup ±}π{sup 0} and π{sup 0}π{sup 0} scattering within the framework of the constituent chiral quark model (CχQM) in the limit of a large number of colours N{sub c} and discuss their asymptotic behaviours. The same ππ cross sections are also discussed within the general framework of Large-N{sub c} QCD and we show that it is possible to make an Ansatz for the isospin I=1 and I=0 spectrum which satisfy the Froissart-Martin bound with coefficients which, contrary to the Lukaszuk-Martin coefficient, are not singular in the chiral limit and have the correct Large-N{sub c} counting. We finally propose a simple phenomenological model which matches the low energy behaviours of the σ{sub π{sup ±}π{sup 0total}}(s) cross section predicted by the CχQM with the high energy behaviour predicted by the Large-N{sub c} Ansatz. The magnitude of these cross sections at very high energies is of the order of those observed for the pp and pp-bar scattering total cross sections.

Asymptotic behaviour of pion-pion total cross-sections

International Nuclear Information System (INIS)

Greynat, David; Rafael, Eduardo de; Vulvert, Grégory

2014-01-01

We derive a sum rule which shows that the Froissart-Martin bound for the asymptotic behaviour of the ππ total cross sections at high energies, if modulated by the Lukaszuk-Martin coefficient of the leading log 2  s behaviour, cannot be an optimal bound in QCD. We next compute the total cross sections for π + π − , π ± π 0 and π 0 π 0 scattering within the framework of the constituent chiral quark model (CχQM) in the limit of a large number of colours N c and discuss their asymptotic behaviours. The same ππ cross sections are also discussed within the general framework of Large-N c QCD and we show that it is possible to make an Ansatz for the isospin I=1 and I=0 spectrum which satisfy the Froissart-Martin bound with coefficients which, contrary to the Lukaszuk-Martin coefficient, are not singular in the chiral limit and have the correct Large-N c counting. We finally propose a simple phenomenological model which matches the low energy behaviours of the σ π ± π 0 total (s) cross section predicted by the CχQM with the high energy behaviour predicted by the Large-N c Ansatz. The magnitude of these cross sections at very high energies is of the order of those observed for the pp and pp-bar scattering total cross sections

Measurement of the Inclusive Upsilon production cross section in pp collisions at sqrt(s)=7 TeV

Energy Technology Data Exchange (ETDEWEB)

Khachatryan, Vardan [Yerevan Physics Inst. (Armenia); et al.

2011-06-01

The Upsilon production cross section in proton-proton collisions at sqrt(s) = 7 TeV is measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3.1 +/- 0.3 inverse picobarns. Integrated over the rapidity range |y|<2, we find the product of the Upsilon(1S) production cross section and branching fraction to dimuons to be sigma(pp to Upsilon(1S) X) B(Upsilon(1S) to mu+ mu-) = 7.37 +/- 0.13^{+0.61}_{-0.42}\\pm 0.81 nb, where the first uncertainty is statistical, the second is systematic, and the third is associated with the estimation of the integrated luminosity of the data sample. This cross section is obtained assuming unpolarized Upsilon(1S) production. If the Upsilon(1S) production polarization is fully transverse or fully longitudinal the cross section changes by about 20%. We also report the measurement of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential cross sections as a function of transverse momentum and rapidity.

Surface tensor estimation from linear sections

DEFF Research Database (Denmark)

Kousholt, Astrid; Kiderlen, Markus; Hug, Daniel

From Crofton's formula for Minkowski tensors we derive stereological estimators of translation invariant surface tensors of convex bodies in the n-dimensional Euclidean space. The estimators are based on one-dimensional linear sections. In a design based setting we suggest three types of estimators....... These are based on isotropic uniform random lines, vertical sections, and non-isotropic random lines, respectively. Further, we derive estimators of the specific surface tensors associated with a stationary process of convex particles in the model based setting....

Surface tensor estimation from linear sections

DEFF Research Database (Denmark)

Kousholt, Astrid; Kiderlen, Markus; Hug, Daniel

2015-01-01

From Crofton’s formula for Minkowski tensors we derive stereological estimators of translation invariant surface tensors of convex bodies in the n-dimensional Euclidean space. The estimators are based on one-dimensional linear sections. In a design based setting we suggest three types of estimators....... These are based on isotropic uniform random lines, vertical sections, and non-isotropic random lines, respectively. Further, we derive estimators of the specific surface tensors associated with a stationary process of convex particles in the model based setting....

Neutron total scattering cross sections of elemental antimony

Energy Technology Data Exchange (ETDEWEB)

Smith, A.B.; Guenther, P.T.; Whalen, J.F.

1982-11-01

Neutron total cross sections are measured from 0.8 to 4.5 MeV with broad resolutions. Differential-neutron-elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of 50 to 200 keV and at scattering angles distributed between 20 and 160 degrees. Lumped-level neutron-inelastic-scattering cross sections are measured over the same angular and energy range. The exPerimental results are discussed in terms of an optical-statistical model and are compared with respective values given in ENDF/B-V.

Neutron total scattering cross sections of elemental antimony

International Nuclear Information System (INIS)

Smith, A.B.; Guenther, P.T.; Whalen, J.F.

1982-11-01

Neutron total cross sections are measured from 0.8 to 4.5 MeV with broad resolutions. Differential-neutron-elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of 50 to 200 keV and at scattering angles distributed between 20 and 160 degrees. Lumped-level neutron-inelastic-scattering cross sections are measured over the same angular and energy range. The exPerimental results are discussed in terms of an optical-statistical model and are compared with respective values given in ENDF/B-V

Total cross sections for heavy flavour production at HERA

CERN Document Server

Frixione, Stefano; Nason, P; Ridolfi, G; Frixione, S; Mangano, M L; Nason, P; Ridolfi, G

1995-01-01

We compute total cross sections for charm and bottom photoproduction at HERA energies, and discuss the relevant theoretical uncertainties. In particular we discuss the problems arising from the small-x region, the uncertainties in the gluon parton density, and the uncertainties in the hadronic component of the cross section. Total electroproduction cross sections, calculated in the Weizs\\"acker-Williams approximation, are also given.

Effect of γ-ray emission on transuranium element production cross sections in heavy ion reactions

International Nuclear Information System (INIS)

Il'inov, A.S.; Oganesyan, Yu.Ts.; Cherepanov, E.A.

1980-01-01

The effect of competition of the γ ray emission with neutron evaporation and of compound nuclei fission induced by heavy ion reactions on the production cross sections for transuranium elements is considered. It is shown that taking account of γ ray emission leads to the broadening of the excitation functions of the (HI, xny) reactions such as 18 O+ 238 U, 40 Ar+ 206 Pb, 40 Ar+ 207 Pb and 40 Ar+ 208 Pb reactions and to the displacement of their maximum toward the higher energies as well as to an increase of the absolute cross sections which is especially strong close to the fusion barrier. Cross sections for the radiative capture of heavy ions by a heavy target nucleus in 40 Ar+ 206 Pb, 40 Ar+ 208 Pb, 48 Ca+ 204 Pb and 48 Ca+ 208 Pb reactions are estimated

Evaluated activation cross-sections and intercomparison of the ...

Indian Academy of Sciences (India)

mental data cross-section with the theoretical codes, to study the quality of the theoretical ... the cross-section, angular distribution, double differential data, gamma ..... TALYS. TENDL. Figure 6. Excitation function of the 87Sr(p, 2n)86Y reaction.

Fusion-fission probabilities, cross sections, and structure notes of superheavy nuclei

International Nuclear Information System (INIS)

Kowal, Michał; Cap, Tomasz; Jachimowicz, Piotr; Skalski, Janusz; Siwek-Wilczyńska, Krystyna; Wilczyński, Janusz

2016-01-01

Fusion – fission probabilities in the synthesis of heaviest elements are discussed in the context of the latest experimental reports. Cross sections for superheavy nuclei are evaluated using the “Fusion by Diffusion” (FBD) model. Predictive power of this approach is shown for experimentally known Lv and Og isotopes and predictions given for Z = 119, 120. Ground state and saddle point properties as masses, shell corrections, pairing energies, and deformations necessary for cross-section estimations are calculated systematically within the multidimensional microscopic-macroscopic method based on the deformed Woods-Saxon single-particle potential. In the frame of the FBD approach predictions for production of elements heavier than Z = 118 are not too optimistic. For this reason, and because of high instability of superheavy nuclei, we comment on some structure effects, connected with the K-isomerism phenomenon which could lead to a significant increase in the stability of these systems.

Total and (n, 2n) neutron cross section measurements on 241Am

International Nuclear Information System (INIS)

Sage, C.

2009-01-01

Neutron induced reaction cross sections on 241 Am have been measured at the IRMM in Geel, Belgium, in the frame of a collaboration between the EC Joint Research Centres IRMM and ITU and French laboratories from CNRS and CEA. Raw material coming from the Atalante facility of CEA Marcoule has been transformed into suitable AmO 2 samples embedded in Al 2 O 3 and Y 2 O 3 matrices. The irradiations for the 241 Am(n, 2n) 240 Am reaction cross section measurement were carried out at the 7 MV Van de Graaff accelerator using the activation technique with quasi mono-energetic neutrons from 8 to 21 MeV produced via the D(d, n) 3 He and the T(d, n) 4 He reactions. The cross section was determined relative to the 27 Al(n, α) 24 Na standard cross section and was investigated for the first time above 15 MeV. The induced activity was measured off-line by standard γ-ray spectrometry using a high purity Ge detector. A special effort was made for the estimation of the uncertainties and the correlations between our experimental points. A different sample of the same isotope 241 Am has been measured in transmission and capture experiments in the resolved resonance region at the neutron ToF facility GELINA. The transmission measurement was performed in two campaigns, with an upgrade of the whole data acquisition system in between, followed by an investigation of its new performances. A preliminary analysis of the resonance parameters tends to confirm the recent evaluation to a higher value for the cross section at the bottom of the first resonances. A new design of C 6 D 6 detectors for capture measurements has been studied, but the data reduction and analysis of the measurement are not part of this work. (author) [fr

Cross section sensitivity and uncertainty analysis for European INTOR and U.S. FED designs

International Nuclear Information System (INIS)

Pelloni, S.

1982-06-01

The European Community International Tokamak Reactor (INTOR-EC) and U.S. Fusion Engineering Device (FED) were used as a basis to investigate the uncertainties of several neutronics performance parameters such as tritium breeding ratio in the blanket, atomic displacement rate in the copper stabilizer, and nuclear heating in the epoxy-based insulator that arise due to nuclear data uncertainties and data processing discrepancies. Neutronics calculations were performed and reaction rates estimated for the recent INTOR-EC using the DLC-37 and DLC-41 cross section libraries. In general, the basic cross section data are known accurately enough to determine the tritium breeding ratio of the INTOR-EC within +-2%. The atomic displacement rate and nuclear heating rate in the superconducting magnet of FED (and presumably also INTOR-EC), however, can be predicted to only about +-12% to 24%. If additional accuracy is required, improved measurements of the iron, chromium, and nickel cross sections in the energy range between 12 and 14 MeV will be needed. (Auth.)

Motor cognitive processing speed estimation among the primary schoolchildren by deriving prediction formula: A cross-sectional study

Directory of Open Access Journals (Sweden)

Vencita Priyanka Aranha

2017-01-01

Full Text Available Objectives: Motor cognitive processing speed (MCPS is often reported in terms of reaction time. In spite of being a significant indicator of function, behavior, and performance, MCPS is rarely used in clinics and schools to identify kids with slowed motor cognitive processing. The reason behind this is the lack of availability of convenient formula to estimate MCPS. Thereby, the aim of this study is to estimate the MCPS in the primary schoolchildren. Materials and Methods: Two hundred and four primary schoolchildren, aged 6–12 years, were recruited by the cluster sampling method for this cross-sectional study. MCPS was estimated by the ruler drop method (RDM. By this method, a metallic stainless steel ruler was suspended vertically such that 5 cm graduation of the lower was aligned between the web space of the child's hand, and the child was asked to catch the moving ruler as quickly as possible, once released from the examiner's hand. Distance the ruler traveled was recorded and converted into time, which is the MCPS. Multiple regression analysis of variables was performed to determine the influence of independent variables on MCPS. Results: Mean MCPS of the entire sample of 204 primary schoolchildren is 230.01 ms ± 26.5 standard deviation (95% confidence interval; 226.4–233.7 ms that ranged from 162.9 to 321.6 ms. By stepwise regression analysis, we derived the regression equation, MCPS (ms = 279.625–5.495 × age, with 41.3% (R = 0.413 predictability and 17.1% (R2 = 0.171 and adjusted R2 = 0.166 variability. Conclusion: MCPS prediction formula through RDM in the primary schoolchildren has been established.

Positron induced scattering cross sections for hydrocarbons relevant to plasma

Science.gov (United States)

Singh, Suvam; Antony, Bobby

2018-05-01

This article explores positron scattering cross sections by simple hydrocarbons such as ethane, ethene, ethyne, propane, and propyne. Chemical erosion processes occurring on the surface due to plasma-wall interactions are an abundant source of hydrocarbon molecules which contaminate the hydrogenic plasma. These hydrocarbons play an important role in the edge plasma region of Tokamak and ITER. In addition to this, they are also one of the major components in the planetary atmospheres and astrophysical mediums. The present work focuses on calculation of different positron impact interactions with simple hydrocarbons in terms of the total cross section (Qtot), elastic cross section (Qel), direct ionization cross section (Qion), positronium formation cross section (Qps), and total ionization cross section (Qtion). Knowing that the positron-plasma study is one of the trending fields, the calculated data have diverse plasma and astrophysical modeling applications. A comprehensive study of Qtot has been provided where the inelastic cross sections have been reported for the first time. Comparisons are made with those available from the literature, and a good agreement is obtained with the measurements.

Neutron standard cross sections in reactor physics - Need and status

International Nuclear Information System (INIS)

Carlson, A.D.

1990-01-01

The design and improvement of nuclear reactors require detailed neutronics calculations. These calculations depend on comprehensive libraries of evaluated nuclear cross sections. Most of the cross sections that form the data base for these evaluations have been measured relative to neutron cross-section standards. The use of these standards can often simplify the measurement process by eliminating the need for a direct measurement of the neutron fluence. The standards are not known perfectly, however; thus the accuracy of a cross-section measurement is limited by the uncertainty in the standard cross section relative to which it is measured. Improvements in a standard cause all cross sections measured relative to that standard to be improved. This is the reason for the emphasis on improving the neutron cross-section standards. The continual process of measurement and evaluation has led to improvements in the accuracy and range of applicability of the standards. Though these improvements have been substantial, this process must continue in order to obtain the high-quality standards needed by the user community

Evaluation of kerma in carbon and the carbon cross sections

International Nuclear Information System (INIS)

Axton, E.J.

1992-02-01

A preliminary simultaneous least squares fit to measurements of kerma in carbon, and carbon cross sections taken from the ENDF/B-V file was carried out. In the calculation the shapes of the total cross section and the various partial cross sections were rigid but their absolute values were allowed to float in the fit within the constraints of the ENDF/B-V uncertainties. The construction of the ENDF/B-V file imposed improbable shapes, particularly in the case of the (12)C(n,n'3(alpha)) reaction, which were incompatible with direct measurements of kerma and of the reaction cross sections. Consequently a new evaluation of the cross section data became necessary. Since the available time was limited the new evaluation concentrated particularly on those aspects of the ENDF/B-V carbon file which would have most impact on kerma calculations. Following the new evaluation of cross sections new tables of kerma factors were produced. Finally, the simultaneous least squares fit to measurements of kerma and the new cross section file was repeated

single-top quark production cross section using the ATLAS detector

CERN Document Server

Feng, Cunfeng; The ATLAS collaboration

2014-01-01

Measurements of single top-quark production cross section in proton proton collisions at 7 and 8 TeV are presented. In the leading order process, a W boson is exchanged in the t-channel. For this process, for the first time a fiducial cross section measured within the detector acceptance is presented and the modelling uncertainty when extrapolating to the total inclusive cross section is assessed with a large number of different Monte Carlo generators. The result is in good agreement with the most up-to-date theory predictions. Furthermore, the single top-quark and anti-top total production cross sections, their ratio, as well as a measurement of the inclusive production cross section is presented. Differential cross sections are measured as a function of the transverse momentum and the absolute value of the rapidity of top and anti-top quarks. In addition, a measurement of the production cross section of a single top quark in association with a W boson is presented. The s-channel production is explored and l...

Effects of cross-section on mechanical properties of Au nanowire

Energy Technology Data Exchange (ETDEWEB)

Vazinishayan, Ali; Yang, Shuming, E-mail: shuming.yang@mail.xjtu.edu.cn; Duongthipthewa, Anchalee; Wang, Yiming [State Key Laboratory for manufacturing system engineering, Xi’an Jiaotong University, Xi’an, 710049 (China)

2016-02-15

The aim of this paper is study of the effects of multiple cross-section of Au nanowire on mechanical properties. Different cross-section models of Au nanowires including circular, hexagonal, pentagonal and rectangular were simulated by finite element modeling using ABAQUS. In this study, the bending technique was applied so that both ends of the model were clamped with mid-span under loading condition. The cross-sections had the length of 400 nm and the diameter of 40 nm, except the circular cross-section while the rest of the cross-sections had an equivalent diameter. Von Misses stresses distribution were used to define the stress distribution in the cross-section under loading condition, and elastic deformation was analyzed by the beam theory. The results disclosed that the circular and the rectangular models had highest and lowest strengths against plastic deformation, respectively.

Invisible anti-cloak with elliptic cross section using phase complement

International Nuclear Information System (INIS)

Yang Yu-Qi; Zhang Min; Yue Jian-Xiang

2011-01-01

Based on the theory of phase complement, an anti-cloak with circular cross section can be made invisible to an object outside its domain. As the cloak with elliptic cross section is more effective to make objects invisible than that with circular cross section, a scaled coordinate system is proposed to design equivalent materials of invisible anti-cloak with elliptic cross section using phase complement. The cloaks with conventional dielectric and double negative parameters are both simulated with the geometrical transformations. The results show that the cloak with elliptic cross section through phase complement can effectively hide the outside objects. (classical areas of phenomenology)

Methods for calculating anisotropic transfer cross sections

International Nuclear Information System (INIS)

Cai, Shaohui; Zhang, Yixin.

1985-01-01

The Legendre moments of the group transfer cross section, which are widely used in the numerical solution of the transport calculation can be efficiently and accurately constructed from low-order (K = 1--2) successive partial range moments. This is convenient for the generation of group constants. In addition, a technique to obtain group-angle correlation transfer cross section without Legendre expansion is presented. (author)

Photoionization cross sections: present status and future needs

International Nuclear Information System (INIS)

Manson, S.T.

1988-01-01

The existing experimental data situation for photoionization cross section of ground-state atoms, excited states and positive ions is reviewed. The ability of theory to predict these cross sections is also discussed. The likely progress for the near future is presented [pt

Neutrino-nucleus cross sections for oscillation experiments

Science.gov (United States)

Katori, Teppei; Martini, Marco

2018-01-01

Neutrino oscillations physics is entering an era of high precision. In this context, accelerator-based neutrino experiments need a reduction in systematic errors to the level of a few percent. Today, one of the most important sources of systematic errors are neutrino-nucleus cross sections which, in the energy region of hundreds of MeV to a few GeV, are known to a precision not exceeding 20%. In this article we review the present experimental and theoretical knowledge of neutrino-nucleus interaction physics. After introducing neutrino-oscillation physics and accelerator-based neutrino experiments, we give an overview of general aspects of neutrino-nucleus cross sections, from both the theoretical and experimental point of view. Then, we focus on these cross sections in different reaction channels. We start with the quasi-elastic and quasi-elastic-like cross section, placing a special emphasis on the multinucleon emission channel, which has attracted a lot of attention in the last few years. We review the main aspects of the different microscopic models for this channel by discussing analogies and the differences among them. The discussion is always driven by a comparison with the experimental data. We then consider the one-pion production channel where agreement between data and theory remains highly unsatisfactory. We describe how to interpret pion data, and then analyze, in particular, the puzzle related to the difficulty of theoretical models and Monte Carlo to simultaneously describe MiniBooNE and MINERvA experimental results. Inclusive cross sections are also discussed, as well as the comparison between the {ν }μ and {ν }e cross sections, relevant for the charge-conjugation-parity violation experiments. The impact of nuclear effects on the reconstruction of neutrino energy and on the determination of the neutrino-oscillation parameters is also reviewed. Finally, we look to the future by discussing projects and efforts in relation to future detectors, beams

Inclined Bodies of Various Cross Sections at Supersonic Speeds

Science.gov (United States)

Jorgensen, Leland H.

1958-01-01

To aid in assessing effects of cross-sectional shape on body aerodynamics, the forces and moments have been measured for bodies with circular, elliptic, square, and triangular cross sections at Mach numbers 1.98 and 3.88. Results for bodies with noncircular cross sections have been compared with results for bodies of revolution having the same axial distribution of cross-sectional area (and, thus, the same equivalent fineness ratio). Comparisons have been made for bodies of fineness ratios 6 and 10 at angles of attack from 0 deg to about 20 deg and for Reynolds numbers, based on body length, of 4.0 x 10(exp 6) and 6.7 x 10(exp 6). The results of this investigation show that distinct aerodynamic advantages can be obtained by using bodies with noncircular cross sections. At certain angles of bank, bodies with elliptic, square, and triangular cross sections develop considerably greater lift and lift-drag ratios than equivalent bodies of revolution. For bodies with elliptic cross sections, lift and pitching-moment coefficients can be correlated with corresponding coefficients for equivalent circular bodies. It has been found that the ratios of lift and pitching-moment coefficients for an elliptic body to those for an equivalent circular body are practically constant with change in both angle of attack and Mach number. These lift and moment ratios are given very accurately by slender-body theory. As a result of this agreement, the method of NACA Rep. 1048 for computing forces and moments for bodies of revolution has been simply extended to bodies with elliptic cross sections. For the cases considered (elliptic bodies of fineness ratios 6 and 10 having cross-sectional axis ratios of 1.5 and 2), agreement of theory with experiment is very good. As a supplement to the force and moment results, visual studies of the flow over bodies have been made by use of the vapor-screen, sublimation, and white-lead techniques. Photographs from these studies are included in the report.

Study of evaporation residue cross-section for 48Ti + 140,142Ce systems

International Nuclear Information System (INIS)

Kaur, Devinder Pal; Behera, B.R.; Kaur, M.

2017-01-01

For understanding the reaction mechanism of heavy compound nucleus (CN), the study of evaporation residue (ER) cross-section plays a vital role. For heavier systems, the probability of formation of CN is strongly influenced by the properties of the di-nuclear system at contact configuration, where entrance channel plays a major role in reaction dynamics. Nuclear structure of the colliding nuclei also plays a key role, which influence the fusion probability. In some of the recent studies the dependence of the fusion reaction on the nuclear shell structure of projectile and target nuclei was also investigated and the importance of N = 82 in the heavy ion fusion reaction was proposed. It was reported that shell closure of one of the interacting nuclei can lead to the enhanced ER cross-section and helps in the synthesis of heavy nuclei. Keeping these points in mind, a systematic measurement of ER cross sections for 48 Ti + 140,142 Ce, 124 Sn systems was performed. Here, 140 Ce target is neutron shell closed (N T =82) but 142 Ce have 84 neutrons. By comparing the ER cross-sections of these systems, the effect of neutron shell closure on fusion probability can be examined. The ER excitation function for third system ( 48 Ti + 124 Sn) was also measured at few energy points to estimate the transmission efficiency of the spectrometer

Nuclear reactions cross section measurement using Z-pinch technology

Energy Technology Data Exchange (ETDEWEB)

Bulgakov, T; Bystritskij, V; Mesyats, G A [Russian Academy of Sciences, Tomsk (Russian Federation). Institute of Electrophysics; and others

1997-12-31

Direct experimental estimate of the upper limit of the d + d {yields} {sup 3}He + n cross-section at deuteron energies below the keV region was obtained for the first time. The experiment was performed at the Pulsed Ion Beam Accelerator of the High-Current Electronics Institute in Tomsk, using high intensity, radially converging deuteron beams, generated during implosion of liner plasma. A two-jet liner made of 17% D{sub 2} + 83% N{sub 2} gas was used, with the inner jet serving as the target. The dd-fusion neutrons were registered by time-of-flight scintillator spectrometers and BF{sub 3} detectors of thermal neutrons placed in a polyethylene moderator. The upper limit obtained for the d + d {yields} {sup 3}He + n cross-section for a deuteron energy of 440 eV is {sigma} < 2 x 10{sup -34} cm{sup 2} at the 90% confidence level. The result demonstrates that the liner implosion technique can be used in the investigation of nuclear reactions between light nuclei at infra low energies, previously not accessible in experiments with classical beam accelerators. (author). 7 refs.

Top quark pair production cross section in the lepton+jets channel using b-tagging at D0

International Nuclear Information System (INIS)

Yoo, H.D.

2008-01-01

The top quark pair production cross section measurement in the lepton+jets channel with b-tagging algorithm is described. About 900 pb -1 data collected by the D0 detector at the Fermilab Tevatron are used for this analysis. In this thesis, event selection, background estimation, and cross section calculation are discussed in detail. In addition, calibration of the Luminosity Monitor readout electronics and a new b-tagging algorithm, the SLTNN tagger, are also discussed in this thesis

Priority cross-sections. Joint Nordic analyses of important cross-sections in the Nordel system. Main report

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-06-01

The Nordic Grid Master Plan 2002 shed light on the energy and power balance for the Nordel area but with special focus on 2005. There was a lot to suggest that the tradi-tional transport patterns with frequent southbound transports would change and be more frequently replaced by northbound transports. Against this background, a number of cross-sections were identified within the Nordel area where expansion is expected to have considerable significance for the Nordic elec-tricity market. The present report 'Priority Cross-sections' concludes the work which was started with the grid master plan. The priority cross-sections are subjected to a technical and socio-economic analysis. The analysis aims to understand the transports in the Nordel system and to support Nor-del when prioritizing forthcoming initiatives. The market price is the driving force for the initiatives which will be carried out on the supply and demand side. The commissioning and decommissioning of commercial pro-duction capacity is determined by the market players, and the task of the transmission system operators (TSOs) is to ensure a robust infrastructure for the smooth operation of the electricity market. (au)

Measurement of actinide neutron cross sections

International Nuclear Information System (INIS)

Firestone, Richard B.; Nitsche, Heino; Leung, Ka-Ngo; Perry, DaleL.; English, Gerald

2003-01-01

The maintenance of strong scientific expertise is critical to the U.S. nuclear attribution community. It is particularly important to train students in actinide chemistry and physics. Neutron cross-section data are vital components to strategies for detecting explosives and fissile materials, and these measurements require expertise in chemical separations, actinide target preparation, nuclear spectroscopy, and analytical chemistry. At the University of California, Berkeley and the Lawrence Berkeley National Laboratory we have trained students in actinide chemistry for many years. LBNL is a leader in nuclear data and has published the Table of Isotopes for over 60 years. Recently, LBNL led an international collaboration to measure thermal neutron capture radiative cross sections and prepared the Evaluated Gamma-ray Activation File (EGAF) in collaboration with the IAEA. This file of 35, 000 prompt and delayed gamma ray cross-sections for all elements from Z=1-92 is essential for the neutron interrogation of nuclear materials. LBNL has also developed new, high flux neutron generators and recently opened a 1010 n/s D+D neutron generator experimental facility

Total cross-sections for reactions of high energy particles (including elastic, topological, inclusive and exclusive reactions). Subvol. b

International Nuclear Information System (INIS)

Schopper, H.; Moorhead, W.G.; Morrison, D.R.O.

1988-01-01

The aim of this report is to present a compilation of cross-sections (i.e. reaction rates) of elementary particles at high energy. The data are presented in the form of tables, plots and some fits, which should be easy for the reader to use and may enable him to estimate cross-sections for presently unmeasured energies. We have analyzed all the data published in the major Journals and Reviews for momenta of the incoming particles larger than ≅ 50 MeV/c, since the early days of elementary particle physics and, for each reaction, we have selected the best cross-section data available. We have restricted our attention to integrated cross-sections, such as total cross-sections, exclusive and inclusive cross-sections etc., at various incident beam energies. We have disregarded data affected by geometrical and/or kinematical cuts which would make them not directly comparable to other data at different energies. Also, in the case of exclusive reactions, we have left out data where not all of the particles in the final state were unambiguously identified. This work contains reactions induced by neutrinos, gammas, charged pions, kaons, nucleons, antinucleons and hyperons. (orig./HSI)

238U subthreshold neutron induced fission cross section

International Nuclear Information System (INIS)

Difilippo, F.C.; Perez, R.B.; De Saussure, G.; Olsen, D.K.; Ingle, R.W.

1976-01-01

High resolution measurements of the 238 U neutron induced fission cross section are reported for neutron energies between 600 eV and 2 MeV. The average subthreshold fission cross section between 10 and 100 keV was found to be 44 +- 6 μb

Fission cross sections in the intermediate energy region

International Nuclear Information System (INIS)

Lisowski, P.W.; Gavron, A.; Parker, W.E.; Ullmann, J.L.; Balestrini, S.J.; Carlson, A.D.; Wasson, O.A.; Hill, N.W.

1991-01-01

Until recently there has been very little cross section data for neutron-induced fission in the intermediate energy region, primarily because no suitable neutron source has existed. At Los Alamos, the WNR target-4 facility provides a high-intensity source of neutrons nearly ideal for fission measurements extending from a fraction of a MeV to several hundred MeV. This paper summarizes the status of fission cross section data in the intermediate energy range (En > 30 MeV) and presents our fission cross section data for 235 U and 238 U compared to intranuclear cascade and statistical model predictions

Fission cross sections in the intermediate energy region

Energy Technology Data Exchange (ETDEWEB)

Lisowski, P.W.; Gavron, A.; Parker, W.E.; Ullmann, J.L.; Balestrini, S.J. (Los Alamos National Lab., NM (USA)); Carlson, A.D.; Wasson, O.A. (National Inst. of Standards and Technology, Gaithersburg, MD (USA)); Hill, N.W. (Oak Ridge National Lab., TN (USA))

1991-01-01

Until recently there has been very little cross section data for neutron-induced fission in the intermediate energy region, primarily because no suitable neutron source has existed. At Los Alamos, the WNR target-4 facility provides a high-intensity source of neutrons nearly ideal for fission measurements extending from a fraction of a MeV to several hundred MeV. This paper summarizes the status of fission cross section data in the intermediate energy range (En > 30 MeV) and presents our fission cross section data for {sup 235}U and {sup 238}U compared to intranuclear cascade and statistical model predictions.

Polynomial parameterized representation of macroscopic cross section for PWR reactor

International Nuclear Information System (INIS)

Fiel, Joao Claudio B.

2015-01-01

The purpose of this work is to describe, by means of Tchebychev polynomial, a parameterized representation of the homogenized macroscopic cross section for PWR fuel element as a function of soluble boron concentration, moderator temperature, fuel temperature, moderator density and 235 U 92 enrichment. Analyzed cross sections are: fission, scattering, total, transport, absorption and capture. This parameterization enables a quick and easy determination of the problem-dependent cross-sections to be used in few groups calculations. The methodology presented here will enable to provide cross-sections values to perform PWR core calculations without the need to generate them based on computer code calculations using standard steps. The results obtained by parameterized cross-sections functions, when compared with the cross-section generated by SCALE code calculations, or when compared with K inf , generated by MCNPX code calculations, show a difference of less than 0.7 percent. (author)

Damage energy and displacement cross sections: survey and sensitivity

International Nuclear Information System (INIS)

Doran, D.G.; Parkin, D.M.; Robinson, M.T.

1976-10-01

Calculations of damage energy and displacement cross sections using the recommendations of a 1972 IAEA Specialists' Meeting are reviewed. The sensitivity of the results to assumptions about electronic energy losses in cascade development and to different choices respecting the nuclear cross sections is indicated. For many metals, relative uncertainties and sensitivities in these areas are sufficiently small that adoption of standard displacement cross sections for neutron irradiations can be recommended

Cross section recondensation method via generalized energy condensation theory

International Nuclear Information System (INIS)

Douglass, Steven; Rahnema, Farzad

2011-01-01

Highlights: → A new method is presented which corrects for core environment error from specular boundaries at the lattice cell level. → Solution obtained with generalized energy condensation provides improved approximation to the core level fine-group flux. → Iterative recondensation of the cross sections and unfolding of the flux provides on-the-fly updating of the core cross sections. → Precomputation of energy integrals and fine-group cross sections allows for easy implementation and efficient solution. → Method has been implemented in 1D and shown to correct the environment error, particularly in strongly heterogeneous cores. - Abstract: The standard multigroup method used in whole-core reactor analysis relies on energy condensed (coarse-group) cross sections generated from single lattice cell calculations, typically with specular reflective boundary conditions. Because these boundary conditions are an approximation and not representative of the core environment for that lattice, an error is introduced in the core solution (both eigenvalue and flux). As current and next generation reactors trend toward increasing assembly and core heterogeneity, this error becomes more significant. The method presented here corrects for this error by generating updated coarse-group cross sections on-the-fly within whole-core reactor calculations without resorting to additional cell calculations. In this paper, the fine-group core flux is unfolded by making use of the recently published Generalized Condensation Theory and the cross sections are recondensed at the whole-core level. By iteratively performing this recondensation, an improved core solution is found in which the core-environment has been fully taken into account. This recondensation method is both easy to implement and computationally very efficient because it requires precomputation and storage of only the energy integrals and fine-group cross sections. In this work, the theoretical basis and development

Poster - 18: New features in EGSnrc for photon cross sections

Energy Technology Data Exchange (ETDEWEB)

Ali, Elsayed; Mainegra-Hing, Ernesto; Rogers, David W.O. [The Ottawa Hospital Cancer Centre, National Research Council Canada, Carleton University (Canada)

2016-08-15

Purpose: To implement two new features in the EGSnrc Monte Carlo system. The first is an option to account for photonuclear attenuation, which can contribute a few percent to the total cross section at the higher end of the energy range of interest to medical physics. The second is an option to use exact NIST XCOM photon cross sections. Methods: For the first feature, the photonuclear total cross sections are generated from the IAEA evaluated data. In the current, first-order implementation, after a photonuclear event, there is no energy deposition or secondary particle generation. The implementation is validated against deterministic calculations and experimental measurements of transmission signals. For the second feature, before this work, if the user explicitly requested XCOM photon cross sections, EGSnrc still used its own internal incoherent scattering cross sections. These differ by up to 2% from XCOM data between 30 keV and 40 MeV. After this work, exact XCOM incoherent scattering cross sections are an available option. Minor interpolation artifacts in pair and triplet XCOM cross sections are also addressed. The default for photon cross section in EGSnrc is XCOM except for the new incoherent scattering cross sections, which have to be explicitly requested. The photonuclear, incoherent, pair and triplet data from this work are available for elements and compounds for photon energies from 1 keV to 100 GeV. Results: Both features are implemented and validated in EGSnrc.Conclusions: The two features are part of the standard EGSnrc distribution as of version 4.2.3.2.

MINERvA - neutrino nucleus cross section experiment

CERN Multimedia

CERN. Geneva

2014-01-01

Recent results from MINERvA, a neutrino cross section experiment at Fermilab, are presented. MINERVA has the goal of providing precision results which will have important impact on oscillation experiments.  Initial data runs for muon neutrino and antineutrino beams of ~3.5 GeV have produced a large number of new results. This seminar will introduce the experiment and describe results for quasielastic, pion production, and inclusive cross sections.

Evaluation methods for neutron cross section standards

International Nuclear Information System (INIS)

Bhat, M.R.

1980-01-01

Methods used to evaluate the neutron cross section standards are reviewed and their relative merits, assessed. These include phase-shift analysis, R-matrix fit, and a number of other methods by Poenitz, Bhat, Kon'shin and the Bayesian or generalized least-squares procedures. The problems involved in adopting these methods for future cross section standards evaluations are considered, and the prospects for their use, discussed. 115 references, 5 figures, 3 tables

Evaluation of cross sections for neutron-induced reactions in sodium

International Nuclear Information System (INIS)

Larson, D.C.

1980-09-01

An evaluation of the neutron-induced cross sections of 23 Na has been done for the energy range from 10 -5 eV to 20 MeV. All significant cross sections are given, including differential cross sections for production of gamma rays. The recommended values are based on experimental data where available, and use results of a consistent model code analysis of available data to predict cross sections where there are no experimental data. This report describes the evaluation that was submitted to the Cross Section Evaluation Working Group (CSEWG) for consideration as a part of the Evaluated Nuclear Data File, Version V, and subsequently issued as MAT 1311. 126 references, 130 figures, 14 tables

Differential bremsstrahlung and pair production cross sections at high energies

International Nuclear Information System (INIS)

Olsen, Haakon A.

2003-01-01

Detailed differential cross sections for high energy bremsstrahlung and pair production are derived with specific attention to the differences between the two processes, which are considerable. For the integrated cross sections, which are the only cross sections specifically known until now, the final state integration theorem guarantees that the exact cross section formulas can be exchanged between bremsstrahlung and pair production by the same substitution rules as for the Born-approximation Bethe-Heitler cross sections, for any amount of atomic screening. In fact the theorem states that the Coulomb corrections to the integrated bremsstrahlung and pair production cross sections are identical for any amount of screening. The analysis of the basic differential cross sections leads to fundamental physical differences between bremsstrahlung and pair production. Coulomb corrections occur for pair production in the strong electric field of the atom for 'large' momentum transfer of the order of mc. For bremsstrahlung, on the other hand, the Coulomb corrections take place at a 'large' distance from the atom of the order of ((ℎ/2π)/mc)ε, with a 'small' momentum transfer mc/ε, where ε is the initial electron energy in units of mc 2 . And the Coulomb corrections can be large, of the order of larger than (Z/137) 2 , which is considerably larger than the integrated cross section corrections

Prevalence of Autism Spectrum Disorder in Nurseries in Lebanon: A Cross Sectional Study

Science.gov (United States)

Chaaya, Monique; Saab, Dahlia; Maalouf, Fadi T.; Boustany, Rose-Mary

2016-01-01

In Lebanon, no estimate for autism prevalence exists. This cross-sectional study examines the prevalence of Autism spectrum disorder (ASD) in toddlers in nurseries in Beirut and Mount-Lebanon. The final sample included 998 toddlers (16-48 months) from 177 nurseries. We sent parents the Modified Checklist for Autism in Toddlers (M-CHAT) for…

Positron total scattering cross-sections for alkali atoms

Science.gov (United States)

Sinha, Nidhi; Singh, Suvam; Antony, Bobby

2018-01-01

Positron-impact total scattering cross-sections for Li, Na, K, Rb, Cs and Fr atoms are calculated in the energy range from 5-5000 eV employing modified spherical complex optical potential formalism. The main aim of this work is to apply this formalism to the less studied positron-target collision systems. The results are compared with previous theoretical and experimental data, wherever available. In general, the present data show overall agreement and consistency with other results. Furthermore, we have done a comparative study of the results to investigate the effect of atomic size on the cross-sections as we descend through the group in the periodic table. We have also plotted a correlation graph of the present total cross-sections with polarizability and number of target electrons. The two correlation plots confirm the credibility and consistency of the present results. Besides, this is the first theoretical attempt to report positron-impact total cross-sections of alkali atoms over such a wide energy range.

Isthmus Dependent Atrial Flutter Cycle Length Correlates with Right Atrial Cross-Sectional Area

Directory of Open Access Journals (Sweden)

Kousik Krishnan

2009-05-01

Full Text Available Background: Right atrial flutter cycle length can prolong in the presence of antiarrhythmic drug therapy. We hypothesized that the cycle length of right atrial isthmus dependent flutter would correlate with right atrial cross-sectional area measurements. Methods: 60 patients who underwent ablation for electrophysiologically proven isthmus dependent right atrial flutter, who were not on Class I or Class III antiarrhythmic drugs and had recent 2-dimensional echocardiographic data comprised the study group. Right atrial length and width were measured in the apical four chamber view. Cross-sectional area was estimated by multiplying the length and width. 35 patients had an atrial flutter rate ≥250 bpm (Normal Flutter Group and 25 patients had an atrial flutter rate < 250 bpm (Slow Flutter Group. Results: Mean atrial flutter rate was 283 bpm in the normal flutter group and 227 bpm in the slow flutter group. Mean atrial flutter cycle length was 213 ms in the Normal Flutter Group and 265 ms in the Slow Flutter Group (p<0.0001. Mean right atrial cross sectional area was 1845 mm2 in the Normal Flutter group and 2378 mm2 in the Slow Flutter Group, (p< 0.0001. Using linear regression, CSA was a significant predictor of cycle length (β =0.014 p = 0.0045. For every 1 mm2 increase in cross-sectional area, cycle length is 0.014 ms longer.Conclusion: In the absence of antiarrhythmic medications, right atrial cross sectional area enlargement correlates with atrial flutter cycle length. These findings provide further evidence that historical rate-related definitions of typical isthmus dependent right atrial are not mechanistically valid.

Evaluation of the neutron cross sections of 235U in the thermal energy region. Final report

International Nuclear Information System (INIS)

Leonard, B.R. Jr.; Kottwitz, D.A.; Thompson, J.K.

1976-02-01

The objective of this work has been to improve the knowledge of the thermal cross sections of the fissile nuclei as a step toward providing a standard data base for the nuclear industry. The methodology uses a form of the Adler-Adler multilevel-fission theory and Breit-Wigner multilevel-scattering theory. It incorporates these theories in a general nonlinear least-squares (LSQ) fitting program SIGLEARNThe analysis methodology in this work was applied to the thermal data on 235 U. A reference data file has been developed which includes most of the known data of interest. The first important result of this work is the assessment of the shape uncertainties of the partial cross sections. The results of our studies lead to the following values and error estimates for 235 U g factors in a thermal (20.44 0 C) energy spectrum: g/sub f/ = 0.97751 (+-0.11%); g/sub γ/ = 0.98230 (+-0.14%). A second important result of this study is the development of a recommended set of 2200 m/s (0.0253 eV) values of the parameters and the probable range of further adjustment which might be made. The analysis also provides the result of a common interpretation of energy-dependent absolute cross-section data of different measurements to yield a consistent set of experimental 0.0253 eV values with rigorous error estimates. It also provides normalization factors for relative fission and capture cross sections on a common basis with rigorous error estimates. The results of these analyses provide a basis for deciding what new measurements would be most beneficial. The most important of these would be improved direct capture data in the thermal region

The Job Satisfaction-Life Satisfaction Relationship Revisited: Using the Lewbel Estimation Technique to Estimate Causal Effects Using Cross-Sectional Data

OpenAIRE

Vinod Mishra; Ingrid Nielsen; Russell Smyth; Alex Newman

2014-01-01

This paper uses a novel identification strategy proposed by Lewbel (2012, J. Bus. Econ. Stat.) to illustrate how causation between job satisfaction and life satisfaction can be established with cross-sectional data. In addition to examining the relationship between composite job satisfaction and life satisfaction, we consider the relationship between life satisfaction and different facets of job satisfaction. We find evidence of bidirectional causality between job satisfaction and life satisf...

Proton induced single event upset cross section prediction for 0.15 μm six-transistor (6T) silicon-on-insulator static random access memories

International Nuclear Information System (INIS)

Li Lei; Zhou Wanting; Liu Huihua

2012-01-01

In this paper, an efficient physics-based method to estimate the saturated proton upset cross section for six-transistor (6T) silicon-on-insulator (SOI) static random access memory (SRAM) cells using layout and technology parameters is proposed. This method calculates the effects of radiation based on device physics. The simple method handles the problem with ease by SPICE simulations, which can be divided into two stages. At first, it uses a standard SPICE program to predict the cross section for recoiling heavy ions with linear energy transfer (LET) of 14 MeV-cm 2 /mg. Then, the predicted cross section for recoiling heavy ions with LET of 14 MeV-cm 2 /mg is used to estimate the saturated proton upset cross section for 6T SOI SRAM cells with a simple model. The calculated proton induced upset cross section based on this method is in good agreement with the test results of 6T SOI SRAM cells processed using 0.15 μm technology. (author)

Differential neutron production cross sections and neutron yields from stopping-length targets for 113-MeV protons

International Nuclear Information System (INIS)

Meier, M.M.; Amian, W.B.; Clark, D.A.; Goulding, C.A.; McClelland, J.B.; Morgan, G.L.; Moss, C.E.

1989-03-01

We have measured differential (P,ξn) cross sections, d 2 σ/dΩdE/sub n/, from thin targets and absolute neutron yields from stopping-length targets at angles of 7.5/degree/, 30/degree/, 60/degree/, and 150/degree/, for the 113--MeV proton bombardment of elemental beryllium, carbon, aluminum, iron, and depleted uranium. Additional cross-section measurements are reported for oxygen, tungsten, and lead. We used time-of-flight techniques to identify and discriminate against backgrounds and to determine the neutron energy spectrum. Comparison of the experimental data with intranuclear-cascade evaporation-model calculations with the code HETC showed discrepancies as high as a factor of 7 in the differential cross sections. These discrepancies in the differential cross sections make it possible to identify some of the good agreement seen in the stopping-length yield comparisons as fortuitous cancellation of incorrect production estimates in different energy regimes. 13 refs., 20 figs., 4 tabs

pp production cross sections and the constraint method

International Nuclear Information System (INIS)

Anjos, J.C.; Santoro, A.F.S.; Souza, M.H.G.

1983-01-01

A method of constructing production cross sections that satisfy the constraints represented by the first few moments is shown to give an excellent account of the data when applied to the high energy pp production cross section ν sub(n) (s) plotted as functions of n. (Author) [pt

Total Cross Sections at High Energies An update

CERN Document Server

Fazal-e-Aleem, M; Alam, Saeed; Qadee-Afzal, M

2002-01-01

Current and Future measurements for the total cross sections at E-811, PP2PP, CSM, FELIX and TOTEM have been analyzed using various models. In the light of this study an attempt has been made to focus on the behavior of total cross section at very high energies.

Statistical analysis of correlated experimental data and neutron cross section evaluation

International Nuclear Information System (INIS)

Badikov, S.A.

1998-01-01

The technique for evaluation of neutron cross sections on the basis of statistical analysis of correlated experimental data is presented. The most important stages of evaluation beginning from compilation of correlation matrix for measurement uncertainties till representation of the analysis results in the ENDF-6 format are described in details. Special attention is paid to restrictions (positive uncertainty) on covariation matrix of approximate parameters uncertainties generated within the method of least square fit which is derived from physical reasons. The requirements for source experimental data assuring satisfaction of the restrictions mentioned above are formulated. Correlation matrices of measurement uncertainties in particular should be also positively determined. Variants of modelling the positively determined correlation matrices of measurement uncertainties in a situation when their consequent calculation on the basis of experimental information is impossible are discussed. The technique described is used for creating the new generation of estimates of dosimetric reactions cross sections for the first version of the Russian dosimetric file (including nontrivial covariation information)

Fault-related-folding structure and reflection seismic sections. Construction of earth model using balanced cross section; Danso ga kaizaisuru shukyoku kozo no keitai to jishin tansa danmen. 1. Balanced cross section wo mochiita chika model no kochiku

Energy Technology Data Exchange (ETDEWEB)

Matsuoka, T; Tamagawa, T [Japan Petroleum Exploration Corp., Tokyo (Japan); Tsukui, R [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

1997-05-27

Pre-stacking depth migration treatment is studied for the estimation of the fold configuration from seismic survey cross sections. The estimation of a velocity structure is necessary for the execution of such treatment, and the utilization of structural-geological knowledge is required for its interpretation. The concept of balanced cross section in relation to the fault-bend fold constructs a stratum structure model under conditions that the deformation during fold and fault formation is a planar strain, that there is no change in volume due to deformation, and that a fold is a parallel fold. In addition to the above geometric and kinetic approach, there is another fold formation process simulation model using a Newtonian fluid for study from the viewpoint of dynamics. This simulation stands on the presumption that the boundary contains a ramp that had been in presence before fold formation and that an incompressible viscous matter is mounted on the top surface. The viscous matter flows and deforms for the formation of an anticline on the ramp. Such enables the reproduction of a fault-bend fold formation process, and helpful discussion may be furthered on the dynamic aspect of this simulation. 5 refs., 4 figs.

Slope of differential cross sections and size of hadron spin-flip amplitude

International Nuclear Information System (INIS)

Selyugin, O.V.

1998-01-01

A possibility to obtain restrictions of the size of the elastic spin-flip hadron scattering amplitude from the exactly measured experimental data on the differential cross sections of elastic hadron-hadron scattering is shown and possible sizes are calculated. Appropriate estimations confirm the previous analysis of experimental data at √s = 540 GeV and a probable contribution of the hadron spin-flip amplitude

Top quark pair production cross section in the lepton+jets channel using b-tagging at D0

Energy Technology Data Exchange (ETDEWEB)

Yoo, Hwidong D. [Brown Univ., Providence, RI (United States)

2008-05-01

The top quark pair production cross section measurement in the lepton+jets channel with b-tagging algorithm is described. About 900 pb^-1 data collected by the D0 detector at the Fermilab Tevatron are used for this analysis. In this thesis, event selection, background estimation, and cross section calculation are discussed in detail. In addition, calibration of the Luminosity Monitor readout electronics and a new b-tagging algorithm, the SLTNN tagger, are also discussed in this thesis.

Pion-nucleus cross sections approximation

International Nuclear Information System (INIS)

Barashenkov, V.S.; Polanski, A.; Sosnin, A.N.

1990-01-01

Analytical approximation of pion-nucleus elastic and inelastic interaction cross-section is suggested, with could be applied in the energy range exceeding several dozens of MeV for nuclei heavier than beryllium. 3 refs.; 4 tabs

Mass spectra and fusion cross sections for 20Ne+24Mg interaction at 55 and 85 MeV

International Nuclear Information System (INIS)

Grotowski, K.; Belery, P.; Delbar, T.; El Masri, Y.; Gregoire, G.; Janssens, R.; Vervier, J.; Paic, G.; Albinska, M.; Albinski, J.; Kopta, S.; Kozik, T.; Planeta, R.

1981-01-01

Inclusive γ spectra from the 20 Ne+ 24 Mg interaction have been measured using 55- and 85-MeV 20 Ne ions. The identification of γ lines allows the determination of mass spectra in the region 12< or =A< or =43. Experimental results are compared with statistical model calculations. The total reaction and fusion cross sections are extracted. Cross sections for inelastic scattering, few nucleon transfers, and deep inelastic scattering are estimated

Electron collision cross section sets of TMS and TEOS vapours

Science.gov (United States)

Kawaguchi, S.; Takahashi, K.; Satoh, K.; Itoh, H.

2017-05-01

Reliable and detailed sets of electron collision cross sections for tetramethylsilane [TMS, Si(CH3)4] and tetraethoxysilane [TEOS, Si(OC2H5)4] vapours are proposed. The cross section sets of TMS and TEOS vapours include 16 and 20 kinds of partial ionization cross sections, respectively. Electron transport coefficients, such as electron drift velocity, ionization coefficient, and longitudinal diffusion coefficient, in those vapours are calculated by Monte Carlo simulations using the proposed cross section sets, and the validity of the sets is confirmed by comparing the calculated values of those transport coefficients with measured data. Furthermore, the calculated values of the ionization coefficient in TEOS/O2 mixtures are compared with measured data to confirm the validity of the proposed cross section set.

Cross-sections of 45Sc(n,2n)44m,gSc reaction from the reaction threshold to 20 MeV

International Nuclear Information System (INIS)

Luo, J.; Peking Univ., Beijing; Liu, R.; Jiang, L.; Liu, Z.; Sun, G.; Ge, S.

2013-01-01

Cross sections of 45 Sc(n,2n) 44m,g Sc reactions and their isomeric cross section ratios σ m /σ g have been measured at three neutron energies between 13.5 and 14.8 MeV using the activation technique. The pure cross section of the groundstate was then obtained by utilizing the absolute cross section of the metastable state and analysis methods of residual nuclear decay. The monoenergetic neutron beam was produced via the 3 H(d, n) 4 He reaction. The cross sections were also estimated with the TALYS-1.2 nuclear model code using different level density options, at neutron energies varying from the reaction threshold to 20 MeV. Results are also discussed and compared with some corresponding values found in the literature. (orig.)

LINEAR2007, Linear-Linear Interpolation of ENDF Format Cross-Sections

International Nuclear Information System (INIS)

2007-01-01

1 - Description of program or function: LINEAR converts evaluated cross sections in the ENDF/B format into a tabular form that is subject to linear-linear interpolation in energy and cross section. The code also thins tables of cross sections already in that form. Codes used subsequently need thus to consider only linear-linear data. IAEA1311/15: This version include the updates up to January 30, 2007. Changes in ENDF/B-VII Format and procedures, as well as the evaluations themselves, make it impossible for versions of the ENDF/B pre-processing codes earlier than PREPRO 2007 (2007 Version) to accurately process current ENDF/B-VII evaluations. The present code can handle all existing ENDF/B-VI evaluations through release 8, which will be the last release of ENDF/B-VI. Modifications from previous versions: - Linear VERS. 2007-1 (JAN. 2007): checked against all ENDF/B-VII; increased page size from 60,000 to 600,000 points 2 - Method of solution: Each section of data is considered separately. Each section of File 3, 23, and 27 data consists of a table of cross section versus energy with any of five interpolation laws. LINEAR will replace each section with a new table of energy versus cross section data in which the interpolation law is always linear in energy and cross section. The histogram (constant cross section between two energies) interpolation law is converted to linear-linear by substituting two points for each initial point. The linear-linear is not altered. For the log-linear, linear-log and log- log laws, the cross section data are converted to linear by an interval halving algorithm. Each interval is divided in half until the value at the middle of the interval can be approximated by linear-linear interpolation to within a given accuracy. The LINEAR program uses a multipoint fractional error thinning algorithm to minimize the size of each cross section table

A method for measuring light ion reaction cross-sections

International Nuclear Information System (INIS)

Carlson, R.F.; Ingemarsson, A.; Lantz, M.; Arendse, G.J.; Auce, A.; Cox, A.J.; Foertsch, S.V.; Jacobs, N.M.; Johansson, R.; Nyberg, J.; Peavy, J.; Renberg, P.-U.; Sundberg, O.; Stander, J.A.; Steyn, G.F.; Tibell, G.; Zorro, R.

2005-01-01

An experimental procedure for measuring reaction cross-sections of light ions in the energy range 20-50 MeV/nucleon, using a modified attenuation technique, is described. The detection method incorporates a forward detector that simultaneously measures the reaction cross-sections for five different sizes of the solid angle in steps from 99.1% to 99.8% of the total solid angle. The final reaction cross-section values are obtained by extrapolation to the full solid angle

A method for measuring light ion reaction cross sections

International Nuclear Information System (INIS)

Carlson, R.F.; Ingemarsson, A.; Lantz, M.

2005-03-01

An experimental procedure for measuring reaction cross sections of light ions in the energy range 20-50 MeV/nucleon, using a modified attenuation technique, is described. The detection method incorporates a forward detector that simultaneously measures the reaction cross sections for five different sizes of the solid angles in steps from 99.1 to 99.8% of the total solid angle. The final reaction cross section values are obtained by extrapolation to the full solid angle

Calculated Cross Sections for the Electron Impact Ionization of Molecular Ions

Science.gov (United States)

Deutsch, H.; Becker, K.; Defrance, P.; Onthong, U.; Parajuli, R.; Probst, M.; Matt-Leubner, S.; Maerk, T.

2002-10-01

We report the results of the application of the semi- classical Deutsch-Märk (DM) formalism to the calculation of the absolute electron-impact ionization cross section of the molecular ions H2+, N2+, O2+, CD+, CO+, CO2+, H3O+, and CH4+ for which experimental data have been reported . Where available, we also compare our calculated cross sections with calculated cross sections using the BEB method of Kim and co-workers. The level of agreement between the experimentally determined and calculated cross section is satisfactory in some cases. In all cases, the calculated cross sections exceed the measured cross sections which is not surprising in view of the experimental complications in measuring ionization cross sections of molecular ions due to the presence of competing channels such as ionization dissociative ionization, and dissociative excitation. Work supported in part by FWF, OEAW, and NASA.

Meeting cross-section requirements for nuclear-energy design

Energy Technology Data Exchange (ETDEWEB)

Weisbin, C.R.; de Saussure, G.; Santoro, R.T. (Oak Ridge National Lab., TN (USA)); Gilai, T. (Ben-Gurion Univ. of the Negev, Beersheba (Israel))

1982-01-01

Current requirements in cross-section data that are essential to nuclear-energy programmes are summarized and explained and some insight into how these data might be obtained is provided. The six sections of the paper describe: design parameters and target accuracies; data collection, evaluation and analysis; determination of high-accuracy differential nuclear data for technological applications; status of selected evaluated nuclear data; analysis of benchmark testing; identification of important cross sections and inferred needs.

Neutron Elastic Scattering Cross Sections Experimental Data and Optical Model Cross Section Calculations. A Compilation of Neutron Data from the Studsvik Neutron Physics Laboratory

Energy Technology Data Exchange (ETDEWEB)

Holmqvist, B; Wiedling, T

1969-06-15

Neutron elastic scattering cross section measurements have been going on for a long period at the Studsvik Van de Graaff laboratory. The cross sections of a range of elements have been investigated in the energy interval 1.5 to 8 MeV. The experimental data have been compared with cross sections calculated with the optical model when using a local nuclear potential.

Systematics of fission cross sections at the intermediate energy region

Energy Technology Data Exchange (ETDEWEB)

Fukahori, Tokio; Chiba, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-03-01

The systematics was obtained with fitting experimental data for proton induced fission cross sections of Ag, {sup 181}Ta, {sup 197}Au, {sup 206,207,208}Pb, {sup 209}Bi, {sup 232}Th, {sup 233,235,238}U, {sup 237}Np and {sup 239}Pu above 20 MeV. The low energy cross section of actinoid nuclei is omitted from systematics study, since the cross section has a complicated shape and strongly depends on characteristic of nucleus. The fission cross sections calculated by the systematics are in good agreement with experimental data. (author)

Total cross-section measurements progress in nuclear physics

CERN Document Server

Giacomelli, G; Mulvey, J H

2013-01-01

Total Cross-Section Measurements discusses the cross-sectional dimensions of elementary hadron collisions. The main coverage of the book is the resonance and high energy area of the given collision. A section of the book explains in detail the characteristic of a resonance region. Another section is focused on the location of the high energy region of collision. Parts of the book define the meaning of resonance in nuclear physics. Also explained are the measurement of resonance and the identification of the area where the resonance originates. Different experimental methods to measure the tota

Understanding differences in the body burden-age relationships of bioaccumulating contaminants based on population cross sections versus individuals.

Science.gov (United States)

Quinn, Cristina L; Wania, Frank

2012-04-01

Body burdens of persistent bioaccumulative contaminants estimated from the cross-sectional biomonitoring of human populations are often plotted against age. Such relationships have previously been assumed to reflect the role of age in bioaccumulation. We used a mechanistic modeling approach to reproduce concentration-versus-age relationships and investigate factors that influence them. CoZMoMAN is an environmental fate and human food chain bioaccumulation model that estimates time trends in human body burdens in response to time-variant environmental emissions. Trends of polychlorinated biphenyl (PCB) congener 153 concentrations versus age for population cross sections were estimated using simulated longitudinal data for individual women born at different times. The model was also used to probe the influence of partitioning and degradation properties, length of emissions, and model assumptions regarding lipid content and liver metabolism on concentration-age trends of bioaccumulative and persistent contaminants. Body burden-age relationships for population cross sections and individuals over time are not equivalent. The time lapse between the peak in emissions and sample collection for biomonitoring is the most influential factor controlling the shape of concentration-age trends for chemicals with human metabolic half-lives longer than 1 year. Differences in observed concentration-age trends for PCBs and polybrominated diphenyl ethers are consistent with differences in emission time trends and human metabolic half-lives. Bioaccumulation does not monotonically increase with age. Our model suggests that the main predictors of cross-sectional body burden trends with age are the amount of time elapsed after peak emissions and the human metabolic and environmental degradation rates.

Learning of Cross-Sectional Anatomy Using Clay Models

Science.gov (United States)

Oh, Chang-Seok; Kim, Ji-Young; Choe, Yeon Hyeon

2009-01-01

We incorporated clay modeling into gross anatomy and neuro-anatomy courses to help students understand cross-sectional anatomy. By making clay models, cutting them and comparing cut surfaces to CT and MR images, students learned how cross-sectional two-dimensional images were created from three-dimensional structure of human organs. Most students…

Evaluation for ENDF/B-IV of the neutron cross sections for 235U from 82 eV to 25 keV

International Nuclear Information System (INIS)

Peelle, R.W.

1976-05-01

Capture and fission cross sections for 235 U in the ''unresolved resonance'' energy region were evaluated to permit determination of local-average resonance parameters for the ENDF/B-IV cross section file. Microscopic data were examined for infinitely dilute average fission and capture cross sections and also for intermediate structure unlikely to be reproduced by statistical fluctuations of resonance widths and spacings within known laws. Evaluated cross sections, averaged over lethargy intervals greater than 0.1, were obtained as an average over selected data sets after appropriate renormalization. Estimated uncertainties are given for these evaluated average cross sections. The ''intermediate'' structure fluctuations common to a few independent data sets were approximated by straight lines joining successive cross sections at 120 selected energy points; the cross sections at the vertices were adjusted to reproduce the evaluated average cross sections over the broad energy regions. Data sources and methods are reviewed, output values are tabulated, and some modified procedures are suggested for future evaluations. Evaluated fission and capture integrals for the resolved resonance region are also tabulated. These are not in agreement with integrals based on the resonance parameters of ENDF/B versions III and IV. 8 tables, 5 figures

Measurements of Electron Proton Elastic Cross Sections for 0.4

International Nuclear Information System (INIS)

Christy, M.E.; Abdellah Ahmidouch; Christopher Armstrong; John Arrington; Arshak Asaturyan; Steven Avery; Baker, O.; Douglas Beck; Henk Blok; Bochna, C.W.; Werner Boeglin; Peter Bosted; Maurice Bouwhuis; Herbert Breuer; Brown, D.S.; Antje Bruell; Roger Carlini; Nicholas Chant; Anthony Cochran; Leon Cole; Samuel Danagoulian; Donal Day; James Dunne; Dipangkar Dutta; Rolf Ent; Howard Fenker; Fox, B.; Liping Gan; Haiyan Gao; Kenneth Garrow; David Gaskell; Ashot Gasparian; Don Geesaman; Paul Gueye; Mark Harvey; Roy Holt; Xiaodong Jiang; Cynthia Keppel; Edward Kinney; Yongguang Liang; Wolfgang Lorenzon; Allison Lung; Pete Markowitz; Martin, J.W.; Kevin Mcilhany; David Mckee; David Meekins; Miller, M.A.; Richard Milner; Joseph Mitchell; Hamlet Mkrtchyan; Robert Mueller; Alan Nathan; Gabriel Niculescu; Maria-ioana Niculescu; Thomas O'neill; Vassilios Papavassiliou; Stephen Pate; Rodney Piercey; David Potterveld; Ronald Ransome; Joerg Reinhold; Rollinde, E.; Philip Roos; Adam Sarty; Reyad Sawafta; Elaine Schulte; Edwin Segbefia; Smith, C.; Samuel Stepanyan; Steffen Strauch; Vardan Tadevosyan; Liguang Tang; Raphael Tieulent; Alicia Uzzle; William Vulcan; Stephen Wood; Feng Xiong; Lulin Yuan; Markus Zeier; Benedikt Zihlmann; Vitaliy Ziskin

2004-01-01

We report on precision measurements of the elastic cross section for electron-proton scattering performed in Hall C at Jefferson Lab. The measurements were made at 28 distinct kinematic settings covering a range in momentum transfer of 0.4 < Q2 < 5.5 (GeV/c)2. These measurements represent a significant contribution to the world's cross section data set in the Q2 range, where a large discrepancy currently exists between the ratio of electric to magnetic proton form factors extracted from previous cross section measurements and that recently measured via polarization transfer in Hall A at Jefferson Lab. This data set shows good agreement with previous cross section measurements, indicating that if a heretofore unknown systematic error does exist in the cross section measurements, then it is intrinsic to all such measurements

Electron capture cross sections by O+ from atomic He

International Nuclear Information System (INIS)

Joseph, Dwayne C; Saha, Bidhan C

2009-01-01

The adiabatic representation is used in both the quantal and semi classical molecular orbital close coupling methods (MOCC) to evaluate charge exchange cross sections. Our results show good agreement with experimental cross sections

Electron capture cross sections by O+ from atomic He

Science.gov (United States)

Joseph, Dwayne C.; Saha, Bidhan C.

2009-11-01

The adiabatic representation is used in both the quantal and semi classical molecular orbital close coupling methods (MOCC) to evaluate charge exchange cross sections. Our results show good agreement with experimental cross sections

Photoproton cross section for /sup 19/F

Energy Technology Data Exchange (ETDEWEB)

Tsubota, H [Tohoku Univ., Sendai (Japan). Coll. of General Education; Kawamura, N; Oikawa, S; Uegaki, J I

1975-02-01

Proton energy spectra have been measured at 90/sup 0/ for the /sup 19/F(e,e'p)/sup 18/O reaction in the giant resonance region. The (..gamma..,p/sub 0/) and (..gamma..,p/sub 1/) differential cross sections are extracted from the proton energy spectra by using virtual-photon spectra. The integrated differential cross section of the (..gamma..,p/sub 0/) and (..gamma..,p/sub 1/) reactions are 1.80+-0.27 and 0.50+-0.45 MeV-mb/sr, respectively. The results are discussed with the shell model theory by comparing with the (..gamma..,p/sub 0/) cross section of the neighboring 4n-nucleus /sup 20/Ne. A significant increase of the proton yield leaving the non-ground states is found at 25 MeV of the incident electron energy. This is discussed in terms of the core excitation effect.

Electron-collision cross sections for iodine

International Nuclear Information System (INIS)

Zatsarinny, O.; Bartschat, K.; Garcia, G.; Blanco, F.; Hargreaves, L.R.; Jones, D.B.; Murrie, R.; Brunton, J.R.; Brunger, M.J.; Hoshino, M.; Buckman, S.J.

2011-01-01

We present results from a joint experimental and theoretical study of elastic electron scattering from atomic iodine. The experimental results were obtained by subtracting known cross sections from the measured data obtained with a pyrolyzed mixed beam containing a variety of atomic and molecular species. The calculations were performed using both a fully relativistic Dirac B-spline R-matrix (close-coupling) method and an optical model potential approach. Given the difficulty of the problem, the agreement between the two sets of theoretical predictions and the experimental data for the angle-differential and the angle-integrated elastic cross sections at 40 eV and 50 eV is satisfactory.

Precise measurements of neutron capture cross sections for FP

International Nuclear Information System (INIS)

Nakamura, Shoji; Harada, Hideo; Katoh, Toshio

2000-01-01

The thermal neutron capture cross sections (σ 0 ) and the resonance integrals (I 0 ) of some fission products (FP), such as 137 Cs, 90 Sr, 99 Tc, 129 I and 135 Cs, were measured by the activation and γ-ray spectroscopic methods. Moreover, the cross section measurements were done for other FP elements, such as 127 I, 133 Cs and 134 Cs. This paper provides the summary of the FP cross section measurements, which have been performed by authors. (author)

Habit, Production, and the Cross-Section of Stock Returns

OpenAIRE

Chen, Andrew Y.

2014-01-01

Solutions to the equity premium puzzle should inform us about the cross-section of stock returns. An external habit model with heterogeneous firms reproduces numerous stylized facts about both the equity premium and the value premium. The equity premium is large, time-varying, and linked with consumption volatility. The cross-section of expected returns is log-linear in B/M, and the slope matches the data. The explanation for the value premium lies in the interaction between the cross-section...

Drell-Yan cross section in the jet calculus scheme

International Nuclear Information System (INIS)

Tanaka, Hidekazu; Kobayashi, Hirokazu

2009-01-01

We calculate factorized cross sections for lepton pair production mediated by a virtual photon in hadron-hadron collisions using the jet calculus scheme, in which a kinematical constraint due to parton radiation is taken into account. This method guarantees a proper phase space boundary for subtraction terms. Some properties of the calculated cross sections are examined. We also discuss matching between the hard scattering cross sections and parton showers at the next-to-leading logarithmic (NLL) order of quantum chromodynamics (QCD). (author)

Testing of cross section libraries for TRIGA criticality benchmark

International Nuclear Information System (INIS)