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NUCLEAR SHAPES AT HIGH ANGULAR MOMENTUM

Description: Multiplicities as a function of {gamma}-ray energy have been measured for continuum {gamma}-ray spectra produced in argon- and calcium-induced reactions. A peak sometimes occurs in the multiplicity spectrum, indicating a correlation between {gamma}-ray energy and multiplicity (spin). This correlation can be explained by rotational motion of the nucleus, suggesting basically prolate nuclear shapes. Absence of structure in the multiplicity spectrum is interpreted to indicate non-collective motion, and hence spherical or oblate shapes.
Date: December 1, 1977
Creator: Deleplanque, M.A.; Lee, I.Y.; Stephens, F.S.; Diamond, R.M. & Aleonard, M.M.
Partner: UNT Libraries Government Documents Department

Final Technical Report for the Neutron Detection without Helium-3 Project

Description: This report details the results of the research and development work accomplished for the ‘Neutron Detection without Helium-3’ project conducted during the 2011-2013 fiscal years. The primary focus of the project was to investigate commercially available technologies that might be used in safeguards applications in the relatively near term. Other technologies that are being developed may be more applicable in the future, but were outside the scope of this study.
Date: November 1, 2013
Creator: Ely, James H.; Bliss, Mary; Kouzes, Richard T.; Lintereur, Azaree T.; Robinson, Sean M.; Siciliano, Edward R. et al.
Partner: UNT Libraries Government Documents Department

Direct observation of stochastic domain-wall depinning in magnetic nanowires

Description: The stochastic field-driven depinning of a domain wall pinned at a notch in a magnetic nanowire is directly observed using magnetic X-ray microscopy with high lateral resolution down to 15 nm. The depinning-field distribution in Ni{sub 80}Fe{sub 20} nanowires considerably depends on the wire width and the notch depth. The difference in the multiplicity of domain-wall types generated in the vicinity of a notch is responsible for the observed dependence of the stochastic nature of the domain wall depinning field on the wire width and the notch depth. Thus the random nature of the domain wall depinning process is controllable by an appropriate design of the nanowire.
Date: November 1, 2008
Creator: Im, Mi-Young; Bocklage, Lars; Fischer, Peter & Meier, Guido
Partner: UNT Libraries Government Documents Department

MPACT Fast Neutron Multiplicity System Prototype Development

Description: This document serves as both an FY2103 End-of-Year and End-of-Project report on efforts that resulted in the design of a prototype fast neutron multiplicity counter leveraged upon the findings of previous project efforts. The prototype design includes 32 liquid scintillator detectors with cubic volumes 7.62 cm in dimension configured into 4 stacked rings of 8 detectors. Detector signal collection for the system is handled with a pair of Struck Innovative Systeme 16-channel digitizers controlled by in-house developed software with built-in multiplicity analysis algorithms. Initial testing and familiarization of the currently obtained prototype components is underway, however full prototype construction is required for further optimization. Monte Carlo models of the prototype system were performed to estimate die-away and efficiency values. Analysis of these models resulted in the development of a software package capable of determining the effects of nearest-neighbor rejection methods for elimination of detector cross talk. A parameter study was performed using previously developed analytical methods for the estimation of assay mass variance for use as a figure-of-merit for system performance. A software package was developed to automate these calculations and ensure accuracy. The results of the parameter study show that the prototype fast neutron multiplicity counter design is very nearly optimized under the restraints of the parameter space.
Date: September 1, 2013
Creator: Chichester, D. L.; Pozzi, S. A.; Dolan, J. L.; Kinlaw, M. T.; Thompson, S. J.; Kaplan, A. C. et al.
Partner: UNT Libraries Government Documents Department

THE RISE AND FALL OF THE SPIN ALIGNMENT IN DEEP-INELASTIC REACTIONS

Description: Both the magnitude and alignment of the transferred angular momentum in the reaction {sup 165}Ho + {sup 165}Ho have been measured as a function of Q value via continuum {gamma}-ray multiplicity and anisotropy techniques. Two regimes are observed: A low-Q-value regime where the aligned angular momentum component dominates over the random components, and a large-Q-value regime where the random components dominate and decrease the spin alignment.
Date: July 1, 1980
Creator: Wozniak, G.J.; McDonald, R.J.; Pacheco, A.J.; Hsu, C.C.; Morrissey, D.J.; Sobotka, L.G. et al.
Partner: UNT Libraries Government Documents Department

Unfolding the fission prompt gamma-ray energy and multiplicity distribution measured by DANCE

Description: The nearly energy independence of the {gamma}-ray efficiency and multiplicity response for the DANCE array, the unusual characteristic elucidated in our early technical report (LLNL-TR-452298), gives one a unique opportunity to derive the true prompt {gamma}-ray energy and multiplicity distribution in fission from the measurement. This unfolding procedure for the experimental data will be described in details and examples will be given to demonstrate the feasibility of reconstruction of the true distribution.
Date: October 16, 2010
Creator: Chyzh, A; Wu, C Y; Bredeweg, T; Couture, A; Jandel, M; Ullmann, J et al.
Partner: UNT Libraries Government Documents Department

Fission prompt gamma-ray multiplicity distribution measurements and simulations at DANCE

Description: The nearly energy independence of the DANCE efficiency and multiplicity response to {gamma} rays makes it possible to measure the prompt {gamma}-ray multiplicity distribution in fission. We demonstrate this unique capability of DANCE through the comparison of {gamma}-ray energy and multiplicity distribution between the measurement and numerical simulation for three radioactive sources {sup 22}Na, {sup 60}Co, and {sup 88}Y. The prospect for measuring the {gamma}-ray multiplicity distribution for both spontaneous and neutron-induced fission is discussed.
Date: August 24, 2010
Creator: Chyzh, A; Wu, C Y; Ullmann, J; Jandel, M; Bredeweg, T; Couture, A et al.
Partner: UNT Libraries Government Documents Department

Software Requirements Specification: Multi-scale Epidemiological and Economic Simulation and Analysis (MESA) Scenario Bank

Description: This document builds on the discussion notes from September 21, 2006. It provides a summary of the ideas relating to the scenario bank tables and their associated requirements. Two conceptual groupings were identified for the contents requirements of the scenario bank. The first, called ProjectTemplate, shall consist of <Project, Scenarios, and Miscellaneous Files> groups. The second, ProjectArchive, shall consist of groups of <Project, Scenarios, Results, and Miscellaneous Files>. The figure below illustrates the multiplicity of the associations between the different tables, with color coding used to distinguish between current MESA (brown) and USDA (light green) requirements. Scenario bank tables are shown in black with their general contents specified within the box. The metadata associated with each table is expected to include database key information as well as relevant timestamps. Each File is expected to be a file with an arbitrary format.
Date: November 8, 2006
Creator: Dahlgren, T L; Hazlett, S G; Slone, D M & Smith, S G
Partner: UNT Libraries Government Documents Department

Energy Dependence of High Moments for Net-proton Distributions

Description: High moments of multiplicity distributions of conserved quantities are predicted to be sensitive to critical fluctuations. To understand the effect of the non-critical physics backgrounds on the proposed observable, we have studied various moments of net-proton distributions with AMPT, Hijing, Therminator and UrQMD models, in which no QCD critical point physics is implemented. It is found that the centrality evolution of various moments of net-proton distributions can be uniformly described by a superposition of emission sources. In addition, in the absence of critical phenomena, some moment products of net-proton distributions, related to the baryon number susceptibilities in Lattice QCD calculations, are predicted to be constant as a function of the collision centrality. We argue that a non-monotonic dependence of the moment products as a function of the beam energy may be used to locate the QCD critical point.
Date: July 7, 2010
Creator: Luo, Xiaofeng; Mohanty, Bedangadas; Ritter, Hans Georg & Xu, Nu
Partner: UNT Libraries Government Documents Department

Growth of Long Range Forward-Backward Multiplicity Correlations with Centrality in Au+Au Collisions at sqrt sNN = 200 GeV

Description: Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au+Au and p+p collisions at {radical}s{sub NN} = 200 GeV. Strong short and long range correlations (LRC) are seen in central Au+Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short range correlations are observed in peripheral Au+Au collisions. Both the Dual Parton Model (DPM) and the Color Glass Condensate (CGC) predict the existence of the long range correlations. In the DPM the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC longitudinal color flux tubes generate the LRC. The data is in qualitative agreement with the predictions from the DPM and indicates the presence of multiple parton interactions.
Date: July 5, 2010
Creator: Collaboration, STAR & Abelev, Betty
Partner: UNT Libraries Government Documents Department

Strangeness production in minimum-bias events at CDF

Description: In a recently published paper 1 are emphasized, for the soft subsample extracted from the minimum-bias (MB) dataset of p{bar p} collisions, interesting invariances with the c.m. energy of the charged multiplicity and p{sub T} distributions. We present an analogous study on V{sup 0} production.
Date: January 15, 2003
Creator: Moggi, N.
Partner: UNT Libraries Government Documents Department

Static Bustle: Patterns Achieved Through Repetitive Processes (Artists Statement)

Description: Static Bustle is a gradute work that explores relationships between visual art and sound through experiments with new and traditional media, including sound, video, digital images prints and fibers. Through strategic processes of layering and repetition, the researcher seamlessly unifies this remarkable range of media into an accessible and cohesive vision. Overall, this research shows visual and sonic pattern achieved through repetitive processes.
Date: May 2015
Creator: Vogt, Jonathan C.
Partner: UNT Libraries

Static Bustle: Patterns Achieved Through Repetitive Processes

Description: Static Bustle is a gradute work that explores relationships between visual art and sound through experiments with new and traditional media, including sound, video, digital images prints and fibers. Through strategic processes of layering and repetition, the researcher seamlessly unifies this remarkable range of media into an accessible and cohesive vision. Overall, this research shows visual and sonic pattern achieved through repetitive processes.
Date: May 2015
Creator: Vogt, Jonathan C.
Partner: UNT Libraries

D. acosta et al., the cdf collaboration,

Description: We present a measurement of the ratio of top-quark branching fractions R = {Beta}(t {yields} Wb)/{Beta}(t {yields} Wq) using lepton-plus-jets and dilepton data sets with integrated luminosity of {approx}162 pb{sup -1} collected with the Collider Detector at Fermilab during Run II of the Tevatron. The measurement is derived from the relative numbers of t{bar t} events with different multiplicity of identified secondary vertices. We set a lower limit of R > 0.61 at 95% confidence level.
Date: May 27, 2005
Creator: Physics, Top & Collid, Measurement of B (t -> Wb)/B(t -> Wq) at the
Partner: UNT Libraries Government Documents Department

Can Handheld Plastic Detectors Do Both Gamma and Neutron Isotopic Identification with Directional Source Location?

Description: This paper demonstrates, through MCNPX simulations, that a compact hexagonal array of detectors can be utilized to do both gamma isotopic identification (ID) along with neutron identification while simultaneously finding the direction of the source relative to the detector array. The detector array itself is composed of seven borated polyvinyl toluene (PVT) hexagonal light pipes approximately 4 inches long and with a 1.25 inch face-to-face thickness assembled in a tight configuration. The gamma ID capability is realized through judicious windowing algorithms as is the neutron spectral unfolding. By having multiple detectors in different relative positions, directional determination of the source can be realized. By further adding multiplicity counters to the neutron counts, fission events can be measured.
Date: April 18, 2008
Creator: Hayes, Robert
Partner: UNT Libraries Government Documents Department

Validation of the MCNPX-PoliMi Code to Design a Fast-Neutron Multiplicity Counter

Description: Many safeguards measurement systems used at nuclear facilities, both domestically and internationally, rely on He-3 detectors and well established mathematical equations to interpret coincidence and multiplicity-type measurements for verifying quantities of special nuclear material. Due to resource shortages alternatives to these existing He-3 based systems are being sought. Work is also underway to broaden the capabilities of these types of measurement systems in order to improve current multiplicity analysis techniques. As a part of a Material Protection, Accounting, and Control Technology (MPACT) project within the U.S. Department of Energy's Fuel Cycle Technology Program we are designing a fast-neutron multiplicity counter with organic liquid scintillators to quantify important quantities such as plutonium mass. We are also examining the potential benefits of using fast-neutron detectors for multiplicity analysis of advanced fuels in comparison with He-3 detectors and testing the performance of such designs. The designs are being developed and optimized using the MCNPX-PoliMi transport code to study detector response. In the full paper, we will discuss validation measurements used to justify the use of the MCNPX-PoliMi code paired with the MPPost multiplicity routine to design a fast neutron multiplicity counter with liquid scintillators. This multiplicity counter will be designed with the end goal of safeguarding advanced nuclear fuels. With improved timing qualities associated with liquid scintillation detectors, we can design a system that is less limited by nuclear materials of high activities. Initial testing of the designed system with nuclear fuels will take place at Idaho National Laboratory in a later stage of this collaboration.
Date: July 1, 2012
Creator: Dolan, J. L.; Kaplan, A. C.; Flaska, M.; Pozzi, S. A. & Chichester, D. L.
Partner: UNT Libraries Government Documents Department

MPACT Fast Neutron Multiplicity System Design Concepts

Description: This report documents work performed by Idaho National Laboratory and the University of Michigan in fiscal year (FY) 2012 to examine design parameters related to the use of fast-neutron multiplicity counting for assaying plutonium for materials protection, accountancy, and control purposes. This project seeks to develop a new type of neutron-measurement-based plutonium assay instrument suited for assaying advanced fuel cycle materials. Some current-concept advanced fuels contain high concentrations of plutonium; some of these concept fuels also contain other fissionable actinides besides plutonium. Because of these attributes the neutron emission rates of these new fuels may be much higher, and more difficult to interpret, than measurements made of plutonium-only materials. Fast neutron multiplicity analysis is one approach for assaying these advanced nuclear fuels. Studies have been performed to assess the conceptual performance capabilities of a fast-neutron multiplicity counter for assaying plutonium. Comparisons have been made to evaluate the potential improvements and benefits of fast-neutron multiplicity analyses versus traditional thermal-neutron counting systems. Fast-neutron instrumentation, using for example an array of liquid scintillators such as EJ-309, have the potential to either a) significantly reduce assay measurement times versus traditional approaches, for comparable measurement precision values, b) significantly improve assay precision values, for measurement durations comparable to current-generation technology, or c) moderating improve both measurement precision and measurement durations versus current-generation technology. Using the MCNPX-PoliMi Monte Carlo simulation code, studies have been performed to assess the doubles-detection efficiency for a variety of counter layouts of cylindrical liquid scintillator detector cells over one, two, and three rows. Ignoring other considerations, the best detector design is the one with the most detecting volume. However, operational limitations guide a) the maximum acceptable size of each detector cell (due to PSD performance and maximum-acceptable per-channel data throughput rates, limited by pulse pile-up and the processing rate of the ...
Date: October 1, 2012
Creator: Chichester, D. L.; Pozzi, S. A.; Dolan, J. L.; Kinlaw, M. T.; Kaplan, A. C.; Flaska, M. et al.
Partner: UNT Libraries Government Documents Department

INTERACTIONS OF 200-GeV/c PROTONS WITH EMULSION NUCLEI, CHARGED PARTICLE MULTIPLICITIES

Description: The experimental data on the multiplicity distributions for various kinds of secondaries produced in the proton-nucleus interactions in emulsion at 200 GeV/c and the correlations between them are presented and discussed. All the characteristics of heavy prongs (mean values <n{sub b}>, <n{sub g}>, <N{sub h}>, their distributions and correlations) are independent (or have a very weak dependence) on the collisions energy in the range 20-200 GeV/c. The data contradict to the cascade-evaporation model and qualitatively agree with the mechanism of particle emission via the long-lived intermediate states. The observed weak A-dependence ({approx} A{sup 0.15}) of shower particle distributions is in agreement with the calculated ones according to the simplified two-step model. It is shown that the n{sub s}-distributions agree well with KNO scaling law in the 67-200 GeV/c range, but the form of universal {psi}(n{sub s/n{sub s}})-function has a weak A-dependence.
Date: January 1, 1974
Creator: Anzon, Z.V.; Boos, E.G.; Chasnikov, I.Ya.; Kanygina, E.K.; Khomenko, K.I.; Pavlova, N.P. et al.
Partner: UNT Libraries Government Documents Department

Estimate of the trigger inefficiency due to extra hits in H1 and H2, using clean Chi(2) events

Description: An accurate study of the inefficiency of the trigger selection criterium based on the multiplicity of hits in the two hodoscopes has been done using {chi}{sub 2} events take during the 1991 run, selected requiring that both electron tracks were associated to a Cherenkov hit (so that no multiplicity requirement at trigger level was asked), and a {chi}{sup 2} probability for the kinematic fit bigger than 0.01. In a table it is shown the number of events found for different multiplicities in the two hodoscopes. They have 554/1819 = 30.5 {+-} 1.3% of the events with extra-hits in the two hodoscopes, and they can think of 3 possible sources for this effect: (1) accidental {delta} rays due to the interactions of the beam halo inside or against the walls of the beam pipe give an extra activity on H1 that should be uncorrelated to the hits due to real tracks; (2) {delta} rays at large angles emitted by the electrons interacting with the inner layers of the detector, so that they expect extra-hits close to the real tracks; and (3) the conversion of the {delta} inside the beam pipe and in the inner detectors can give an extra-hit in H2 or H1 and H2: this also doubles the number of sources of {delta} rays, so that a big number of these events have 4 H2 firing.
Date: July 1, 1992
Creator: Mussa, R. & /INFN, Turin /Turin U.
Partner: UNT Libraries Government Documents Department

Universality of Charged Multiplicity Distributions

Description: The charged multiplicity distributions of the diffractive and non-diffractive components of hadronic interactions, as well as those of hadronic states produced in other reactions, are described well by a universal Gaussian function that depends only on the available mass for pionization, has a maximum at n{sub o} {approx_equal} 2M{sup 1/2}, where M is the available mass in GeV, and a peak to width ratio n{sub o}/D {approx_equal} 2.
Date: December 1, 1981
Creator: Goulianos, K. & U., /Rockefeller
Partner: UNT Libraries Government Documents Department

Methods for Attribute Measurement and Alternatives to Multiplicity Counting

Description: The Attribute Measurement System with Information Barrier (AMS/IB) specification is being developed in support of the Defense Threat Redcution Agency's (DTRA's) Cooperative Threat Reduction (CTR) program for the Mayak Fissile Material Storage Facility. This document discusses the technologies available for attribute measurement, and advantages and disadvantages of alternatives.
Date: May 17, 2000
Creator: Kouzes, Richard T. & Geelhood, Bruce D.
Partner: UNT Libraries Government Documents Department

Event-by-Event Fission with FREYA

Description: The recently developed code FREYA (Fission Reaction Event Yield Algorithm) generates large samples of complete fission events, consisting of two receding product nuclei as well as a number of neutrons and photons, all with complete kinematic information. Thus it is possible to calculate arbitrary correlation observables whose behavior may provide unique insight into the fission process. The presentation first discusses the present status of FREYA, which has now been extended up to energies where pre-equilibrium emission becomes significant and one or more neutrons may be emitted prior to fission. Concentrating on {sup 239}Pu(n,f), we discuss the neutron multiplicity correlations, the dependence of the neutron energy spectrum on the neutron multiplicity, and the relationship between the fragment kinetic energy and the number of neutrons and their energies. We also briefly suggest novel fission observables that could be measured with modern detectors.
Date: November 9, 2010
Creator: Randrup, J. & Vogt, R.
Partner: UNT Libraries Government Documents Department

Gamma Ray Multiplicity of 252Cf Spontaneous Fission using LiBerACE

Description: We are studying the gamma ray and neutron multiplicity of various fission processes, beginning with the spontaneous fission of {sup 252}Cf, for a variety of basic and applied science purposes. The Livermore-Berkeley Array for Collaborative Experiments (LiBerACE) consists of six high-purity germanium Clover detectors (HPGe) each enclosed by an array of 16 bismuth-germanate (BGO) detectors. These detectors were arranged in a cubic pattern around a 1 {micro}Ci {sup 252}Cf source to attempt to cover as much solid angle of gamma ray emission as possible with a high level of segmentation. The single-gamma detector response function is determined at several energies by tagging in a HPGe detector on the photopeak of one of two gamma rays in two-gamma ray calibration sources and observing the multiplicity of the remainder of the array. Summing these single-gamma responses in groups yields the response function of the array to higher multiplicity events, which are convolved with multiplicity distributions from theoretical models and compared to the measured results to test the models validity.
Date: January 15, 2008
Creator: Bleuel, D L; Bernstein, L A; Burke, J T; Heffner, M D; Norman, E B; Scielzo, N D et al.
Partner: UNT Libraries Government Documents Department