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The WIMS (Winfrith Improved Multigroup Scheme) reactor physics code is actively being developed for whole core modelling of a range of Small Modular Reactor types including the Pressurized Water Reactor (PWR), High Temperature Reactor (HTR), and Liquid Metal Cooled Fast reactor (LMFR). These developments include the capability for whole core multiphysics modelling with neutronics and thermal hydraulic feedback, as well as methods to determine the power deposition from neutron and gamma heating. Flux solutions are obtained using a wide variety of deterministic methods including diffusion theory, SP3, and full transport with the method of characteristics and Sn discrete ordinates methods, as well as multi-group Monte Carlo methods. The SP3 method allows both steady state and time dependent transient solutions by solving the time dependent SP3 equations. A wide variety of nuclear data libraries are available with WIMS including data from the JEF3.3, ENDF/B-VII.0 and CENDL3.1 nuclear data evaluations. This paper presents validation of the latest version of the WIMS code, WIMS11, for PWR and HTR systems. Comparisons are made against physics data obtained from the OECD/NEA PWR Watts Bar multi-physics benchmark and the IAEA HTR-10 benchmark, as well as neutron and gamma heating experiments that took place on the NESSUS reactor at Winfrith in the United Kingdom. In each case, validation of WIMS has been obtained by comparison either against measured data, or results provided by other benchmark participants that have been obtained with alternative deterministic or Monte Carlo methods. [ABSTRACT FROM AUTHOR]

JENDL group has developed evaluated fission yield and decay data. They are now planned to be upgraded in order to embody new experimental data and theoretical developments obtained after the last release. In this paper, we briefly describe a plan and present activity toward next JENDL fission yield and decay data. [ABSTRACT FROM AUTHOR]

Fission measurements have a long history at Los Alamos. This paper reviews the current programs in neutron-induced fission at the Los Alamos Neutron Science Center. [ABSTRACT FROM AUTHOR]

The first results from the Stopped Beam RISING experimental campaign performed at the GSI laboratory in Darmstadt, Germany, are presented. RISING (Rare ISotope INvestigations at GSI) constitutes a major new experimental program in European nuclear structure physics research aimed at using relativistic-energy, projectile-fragmentation reactions to study nuclei with exotic proton-to-neutron ratios. This paper introduces the physics aims of the Stopped RISING collaboration and presents some technical details and initial results from experiments using the RISING array to study decays from metastable nuclear states in both proton and neutron-rich nuclei. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

In this paper we present the results obtained on the plasma focus PF-1000 in IPPLM Warsaw and on the z-pinch S-300 in RRC Kurchatov Institute in Moscow using a deuterium load. On the PF-1000 plasma-focus device with deuterium filling gas the energy of neutrons and time of their generation are determined by time-of-flight method from seven scintillation detectors positioned in the axial direction. The neutron signals (total yield ∼1011 neutrons per shot) correlate with hard x-rays and their maximum occur ∼150–200 ns after the pinch phase. The initial portion of neutron pulse has beam-target origin with downstream energies up to 2.8–3.2 MeV and the final portion of neutrons has isotropic distribution of energies in the range of 2.2–2.7 MeV. The z-pinch experiments were performed on the S-300 generator with the load formed from a deuterated CD2 fibre in the axis of a tungsten wire array. The energy of neutrons and time of their generation are determined by time-of-flight method from 5 scintillation detectors positioned in the axial and side-on direction. The neutrons with total yield up to 3×109 per shot are produced in the energy range of 1.8–3.2 MeV at 10–30 ns after the pinch phase represented by dip in the current waveform, peak of the voltage and minimum of the pinch diameter. The distribution of neutron velocities is random within the total solid angle. The neutrons in both devices are produced by a non-thermal mechanism with deuterons accelerated to the energies above 100 keV partially in anode-cathode direction and partially with almost isotropic distribution of velocities at the time of the plasma expansion, i.e. after the pinch phase. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We review our strategy to study hadron interactions from lattice QCD using newly proposed potential method. We first explain our strategy in the case of nuclear potentials and its application to nuclear physics. We then discuss the origin of the repulsive core, by adding strange quarks to the system. We also explore a possibility for H-dibaryon to exist in flavor SU(3) limit of lattice QCD. We conclude the paper with an application of our strategy to investigate the maximum mass of neutron stars. [ABSTRACT FROM AUTHOR]

Initially, yields (or abundances) and branching ratios of β-delayed neutrons (βdn) from fission products (Pn-values) have had their main importance in nuclear reactor control. At that time, the six-group mathematical approximation of the time-dependence of βdn-data in terms of the so-called "Keepin groups" was generally accepted. Later, with the development of high-resolution neutron spectroscopy, ßdn data have provided important information on nuclear-structure properties at intermediate excitation energy in nuclei far from stability, as well as in nuclear astrophysics. In this paper, I will present some examples of the βdn-studies performed by the Kernchemie Mainz group during the past three decades. This work has been recognized as an example of "broad scientific diversity" which has led to my nomination for the 2014 Hans A. Bethe prize. [ABSTRACT FROM AUTHOR]

This paper presents some of the challenges ahead of us even after 75 years of the discovery of the fission process and large progress made since then. The focus is on application orientation, which requires improved measurements on fission cross-sections and neutron and γ-ray multiplicities. Experimental possibilities have vastly improved the past decade leading to developments of highly sophisticated detector systems and the use of digital data acquisition and signal processing. The development of innovative fast nuclear reactor technology needs improved respective nuclear data. Advancements in theoretical modelling also require better experimental data. Theory has made progress in calculating fission fragment distributions (i.e. GEF code) as well as prompt neutron and y-ray emission to catch up with the improved experiments. [ABSTRACT FROM AUTHOR]

Elemental characterization of low Z elements (C,H,Cl,Fe) inside bulk materials were performed using PGNAA technique. Samples having elemental composition similar to explosives were used for such experimentations using moderated DD neutrons as well as DT(14MeV) neutrons. We could observe characteristic prompt capture gamma rays of hydrogen (2.224MeV), nitrogen (10.83 MeV), chlorine (6.11 MeV) and Fe (6.02MeV and 7.63MeV) also (n,n'γ) prompt gamma signal (4.43MeV) of carbon. BGO detector has been used for gamma spectrum acquisition. These experimentations has been carried out for initial feasibility studies of detecting prompt gamma lines as a part of PGNAA technique based explosive detection system development. A detail description of experimental set up and procedure has been discussed in paper. [ABSTRACT FROM AUTHOR]

In spite of the huge amount of fission yield data available in different libraries, more accurate values are still needed for nuclear energy applications and to improve our understanding of the fission process. Thus measurements of fission yields were performed at the mass spectrometer Lohengrin at the Institut Laue-Langevin in Grenoble, France. The mass separator Lohengrin is situated at the research reactor of the institute and permits the placement of an actinide layer in a high thermal neutron flux. It separates fragments according to their atomic mass, kinetic energy and ionic charge state by the action of magnetic and electric fields. Coupled to a high resolution ionization chamber the experiment was used to investigate the mass and isotopic yields in the light mass region. Almost all fission yields of isotopes from Th to Cf have been measured at Lohengrin with this method. It has been extended in this work to the heavy mass region for the reactions 235U(nth,f), 239Pu(nth,f), and 241Pu(nth,f). For these higher masses an isotopic separation is no longer possible. So, a new method was undertaken with the reaction 239Pu(nth,f) to determine the isotopic yields by γ spectrometry. The results are presented in this paper. [ABSTRACT FROM AUTHOR]

A renewed interest in photonuclear reactions was stimulated by applications as radioactive ion beam production, irradiation stations by high energy photons, shielding of electron accelerators, etc. Today, a particular attention is paid to the non-destructive characterization of waste barrels and the detection of nuclear materials, both based on photofission process and the associated delayed neutron (DN) and delayed photon (DP) emissions. The need of accurate and complete data for DN and DP yields and time characteristics of actinides was the motivation for an experimental campaign, started in 2004. In this paper, the experimental setup and the data analysis method will be presented and the modeling work will be described. Experimental results for DN and DP characteristics will be compared to calculations in the case of photofission of 232Th, 235,238U, and 237Np. [ABSTRACT FROM AUTHOR]

On the base of modified trajectory calculations the shift of angular distribution of α-particles accompanied the reaction 235U(n,f) induced by cold polarized neutrons is evaluated. It was supposed that angular distribution shift is caused by the rotation of nuclear system before scission. The orientation of a rotation motion is determined by the neutron spin polarization along and opposite to the beam direction. For the first time the estimation was done in the frame of trajectory calculations assuming the rotation motion of scissioning nucleus [1]. The result of the calculation is in a good agreement with experimental data of paper [2], where this new phenomenon was named as ROT-effect. [ABSTRACT FROM AUTHOR]

A new measurement program was set up at SCK·CEN to determine the thermal neutron-induced fission cross section of a number of Cm isotopes. These transuranium isotopes are produced in nuclear reactors and are candidates for transmutation. This paper presents preliminary results of our 245Cm(n,f) cross-section measurement. [ABSTRACT FROM AUTHOR]

In this paper I discuss the first observation of the neutrino by Frederick Reines, Clyde Cowan, and their collaborators. I also discuss how the physics community decided to reject the claim that a new, heavy, 17-keV neutrino had been observed. Both are examples of good science. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Presented in this paper are some of the latest measurements of photoneutron cross sections of direct relevance to the p-process nucleosynthesis in the context of the statistical model of compound nuclear reactions. We discuss the p-process origin of the rarest nuclide and the only naturally occurring isomer 180Tam, a serious underproduction problem of 138La, and the nuclear level density of 180Ta determined from the partial photoneutron cross section for 180Tam. As the laser-Compton scattering γ ray at AIST has enabled one to directly determine (γ,n) cross sections, the blackbody synchrotron radiation to be produced by a ten-Tesla superconducting wiggler at SPring-8 is expected to be a promising tool for exploring (γ,α) and (γ,p) reactions in the future. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Fast neutrons play crucial roles as a probe to trace the history of the universe. The present paper describes our recent work on the measurement of the neutron capture and neutron inelastic scattering cross sections of various nuclei from primordial and stellar nucleostyntheses point of view, which have been carried out by developing a high sensitive measurement system. The obtained results are compared to previous works and theoretical calculations. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

In this paper among the wide-ranging applications of nuclear methods the following topics were selected: a) Nuclear safeguards, illicit trafficking and demining; b) Bulk hydrogen analysis; c) Radiopharmaceuticals and related charged particle reactions; d) Accelerator transmutation of radioactive waste; e) Validation of nuclear data libraries by differential and integral measurements. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Fission cross section of short-lived minor actinides is of prime importance for the incineration of minor actinides in high and thermal neutron fluxes. But due to the shortness of their half-lives, measurements are difficult to handle on these isotopes and the existing data present some large discrepancies. An original method has been developed, in the framework of the Mini-INCA project at ILL, to measure the fission and capture cross sections of minor actinides with low error bars associated even for short-lived isotopes. This method lies on a quasi on-line alpha- and gamma-spectroscopy of irradiated samples and on the use of fission micro-chambers. Coupled to a very powerful Monte-Carlo simulation, both microscopic information on nuclear reactions (total and partial cross sections for neutron capture and/or fission reactions) and macroscopic information on transmutation and incineration potentials could be gathered. In this paper, the method is explained in its originality and some recent results are given and compared with existing measurements and evaluated data libraries. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Long-baseline experiments will play a crucial role in the precision era of neutrino oscillation physics. In this paper we review the ongoing European programme, which is focused on CNGS, and we discuss the opportunities for new facilities based on the CERN acceleration complex. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Using multiple liquid-scintillatior detectors at distances between 0.1 and 3 km from a nuclear reactor has the potential to determine the yet unknown neutrino-mixing angle θ13 via inverse β-decay reaction on protons. The coincidence tag between the emitted prompt positron and delayed neutron provides a clear signature of anti-neutrino event. The neutron capture signal is greatly enhanced by loading gadolinium into the liquid scintillator, due to the large (n, γ) cross sections of Gd isotopes. BNL has developed a procedure to synthesize Gd-loaded scintillator with long attenuation length (> 10 m), high light output (> 95% of pseudocumene), and long-tern stability (> 5 months to date). The purification and chemical quality of BNL-synthesized Gd-LS are discussed in the paper. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Cosmogenic-induced activity is an issue of great concern for many sensitive experiments sited underground. A variety of different arch-type experiments — such as those geared toward the detection of dark matter, neutrinoless double beta decay and solar neutrinos — have reached levels of cleanliness and sensitivity that warrant careful consideration of secondary activity induced by cosmic rays. This paper reviews some of the main issues associated with the modeling of cosmogenic activity underground. Comparison with data, when such data is available, is also presented. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Proton accelerators producing beam powers of up to 1 MW are presently either operating or under construction and designs for Multi-Megawatt facilities are being developed. High beam power has applications in the production of high intensity secondary beams of neutrons, muons, kaons and neutrinos as well as in nuclear waste transmutation and accelerator-driven sub-critical reactors. Each of these applications has additional requirements on beam energy and duty cycle. This paper will review how present designs for future Multi-Megawatt facilities meet these requirements and will also review the experience with present high power facilities. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

High Power Proton Accelerators (HPPAs) are studied for several projects based on high-flux neutron sources driven by proton or deuteron beams. Since the front end is considered as the most critical part of such accelerators, the two French national research agencies CEA and CNRS decided to collaborate in 1997 to study and build a High-Intensity Proton Injector (IPHI). The main objective of this project is to master the complex technologies used and the concepts of manufacturing and controlling the HPPAs. Recently, a collaboration agreement was signed with CERN and led to some evolutions in the design and in the schedule. The IPHI design current was maintained at 100 mA in Continuous Wave mode. This choice should allow to produce a high reliability beam at reduced intensity (typically 30 mA) tending to fulfill the Accelerator Driven System requirements. The output energy of the Radio Frequency Quadrupole (RFQ), was reduced from 5 to 3 MeV, allowing then the adjunction and the test, in pulsed operation of a chopper line developed by CERN for the Superconducting Proton Linac (SPL). In a final step, the IPHI RFQ and the chopper line should become parts of the SPL injector. In this paper, the IPHI project and the recent evolutions are reported together with the construction and operation schedule. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The nuclear Ramsauer model is a semi-classical, analytic approximation to nucleon-nucleus scattering that reproduces total cross-section data at the 1% level for A > 40, En = 5–60 MeV with 7–10 parameters. A quick overview of the model is given, demonstrating the model’s utility in nuclear data evaluation. The Ramsauer model predictions for reaction cross section, elastic cross section, and elastic scattering angular distributions are considered. In a recent paper it has been shown that the nuclear Ramsauer model does not do well in predicting details of the angular distribution of neutron elastic scattering for incident energies of less than 60 MeV for 208Pb. However, in this contribution it is demonstrated that the default angular bin dispersion most widely used in Monte Carlo transport codes is such that the observed differences in angular shapes are on too fine a scale to affect transport calculations. Simple studies indicate that 512–2048 bins are necessary to achieve the dispersion required for calculations to be sensitive to the observed discrepancies in angular distributions. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Proton and neutron data as well as photon data are necessary in various intermediate energy applications. To meet these requirements, many groups in the world continue some activities concerning nuclear data evaluation in the energy range above 20 MeV, which is the upper limit of conventional general-purpose evaluated nuclear data files. In this paper, reviewed is brief history of intermediate energy nuclear data development as well as Pearlstein’s contribution for it. Present status of world evaluated nuclear data files in the intermediate energy region is reported as well as evaluation methodology and sample results of evaluation and integral benchmark tests by using the case of JENDL High Energy File as an example. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

A new evaluated nuclear data library has been created. The library consists of two sub-libraries for neutron and proton incident particles. The first version of neutron sub-library has been completed and described in the present paper. The library contains nuclear data for transport, heating, and shielding applications for 242 nuclides ranging in atomic number from 8 to 82 in the energy region of primary neutrons from 10-5 eV to 150 MeV. Data below 20 MeV are taken mainly from ENDF/B-VI (Revision 8) and for some nuclides, from the JENDL-3.3 and JEFF-3.0 libraries. The evaluation of emitted particle energy and angular distributions at the energies above 20 MeV was performed with the help of the ALICE/ASH code and the analysis of available experimental data. The total cross sections, elastic cross sections, and elastic scattering angular distributions were calculated with the help of the coupled channel model. The results of the calculation were adjusted to the data from ENDF/B-VI, JENDL-3.3m or JEFF-3.0 at the neutron energy equal to 20 MeV. The library is written in ENDF/B-VI format using the MF=3/MT=5 and MF=6/MT=5 representations. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Rhodium-103 is a prominent fission product in nuclear reactors as well as a usual detector in fast neutron activation or dosimetry techniques. The neutron-induced reactions and the energy regions of interest differ significantly depending on the applications. In this paper, a new evaluation spanning the 0- to 30-MeV energy range is described. The quality of the transitions between the various energy intervals was assessed with the help of statistical techniques to test the resonance parameter distributions and the SPRT method to check optical model calculations. The evaluated nuclear data file was verified and processed. The quality of the data was successfully tested against both differential and integral results for activation, thermal and fast reactor applications. This new file should be part of the upcoming JEFF-3.1 library. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The initial objective of this work was an updated review on the Am isotopes data since the next official release (3.1) of the JEFF3 evaluated data file is foreseen around June 2005. Alternatively, this work searches for the possible reasons of the observed discrepancies between differential and integral measurement results. In particular, strong differences are encountered on σγth values and epithermal branching ratio values for the 241Am. Although the JEF2.2 validation is used as guide in parallel with a systematic study of all differential and integral results available, the need for new measurements clearly shows up. This paper finally draws up a list of desired and feasible new differential and integral measurements on the Am isotopes. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Starting with a discussion of the requirements and goals for high quality general-purpose evaluations the paper will describe the procedures chosen in our evaluation work for JEFF for producing new general evaluations with complete covariance information for all cross sections (file 3 data). Key problems essential for the goal of making the best possible use of the existing theoretical and experimental knowledge on neutron interactions with the respective nuclide will be addressed, especially the problem of assigning covariances to calculated cross sections, necessary checking procedures for all experimental data and various possibilities to amend the experimental database beyond the obvious use of EXFOR data for the respective cross sections. In this respect both, the use of elemental cross sections in isotopic evaluations and the use of implicit cross-section data (that is data which can be converted into cross sections by simple methods) will be discussed in some detail. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

This paper presents validation work on MA nuclear data by PIE analyses in the framework of fast-reactor cycle system development. The PIE analyses are in progress on MA samples (237Np, 241Am, 243Am, 244Cm) irradiated at the experimental fast reactor “JOYO.” The preliminary analysis results showed that the isomeric ratio for 241Am capture reaction lies at around 0.85 (g/(g+m)) in the fast-neutron spectra, which suggested the necessity of re-evaluation of the data both in ENDF/B-VI and in JENDL-3.3. From the results on curium isotopes, overestimations could be pointed out for the capture cross section of 244Cm in ENDF/B-VI and that of 245Cm in JENDL-3.3. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Neutron and gamma spectra were measured behind and inside of modules consisting of variable iron and water slabs that were installed in radial beams of the zero-power training and research reactors AKR of the Technical University Dresden and ZLFR of the University of Applied Sciences Zittau/Goerlitz. The applied NE-213 scintillation spectrometer did allow the measurement of gamma and neutron fluence spectra in the energy regions 0.3–10 MeV for photons and 1.0–20 MeV for neutrons. The paper describes the experiments and presents important results of the measurements. They are compared with the results of Monte Carlo transport calculations made by means of the codes MCNP and TRAMO on an absolute scale of fluences. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Experiments with slow neutrons can be used to address a number of scientific issues in the areas of nuclear, particle, and astrophysics, and this conference includes a number of examples. We give in this paper a brief overview of the scientific issues. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The neutron Time of Flight (n_TOF) facility at CERN is a source of a wide-range (1 eV

The Los Alamos Neutron Science Center, or LANSCE, is an accelerator-based national user facility for research in basic and applied science using four experimental areas. LANSCE has two areas that provide neutrons generated by the 800-MeV proton beam striking tungsten target systems. A third area uses the proton beam for radiography. The fourth area uses 100 MeV protons to produce medical radioisotopes. This paper describes the four LANSCE experimental areas, gives nuclear science highlights of the past operating period, and discusses plans for the future. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The author discusses some of the challenges that future nuclear modeling may face in order to improve the description of the nuclear structure. One challenge is related to the need for A-body nuclear interactions justified by various contemporary nuclear physics studies. Another challenge is related to the discrepancy in the NNN contact interaction parameters for 3He and 3H that suggests the need for accurate proton and neutron masses in the future precision calculations. [ABSTRACT FROM AUTHOR]

The article focuses on the use of Gamma-Ray Spectrometer (GRS) method to calculate the uncertainties of calculation parameters of the sodium-cooled fast reactors. It mentions that the calculation errors due changes in neutron data and technological parameters including geometrical and material data are problematic in reactor physics.

We show that extreme nuclear halos are caused only by pairs of s-wave neutrons (or single s-wave neutrons) and that such states occur much more frequently in the periodic table than previously believed. Besides lingering long near zero neutron separation energy such extreme halos have very remarkable properties: they can contribute significantly to the nuclear density at more than twice the normal nuclear radius and their spreading width can be very narrow. The properties of these states are primarily determined by the “thickness” of the nuclear surface in the mean-free nuclear potential and thus their importance increases greatly as we approach the neutron drip line. We discuss what such extreme halos are, where they occur, what their properties are and some of their impact on nuclear observations. [ABSTRACT FROM AUTHOR]

Systematic cross section measurements of alpha-capture reactions at sub-Coulomb energies relevant to the p process were performed in the Ge-Sn region. At the same time a recent global α-nucleus optical model potential (OMP) based on the double-folding method was updated using all existing data on alpha elastic scattering and alpha-induced reactions. In this paper, we report on our recent measurements of alpha-capture reactions and present calculations using the improved alpha-nucleus OMP. [ABSTRACT FROM AUTHOR]

This conference paper outlines the operation and some of the preliminary physics results using the GSI RISING active stopper. Data are presented from an experiment using combined isomer and beta-delayed gamma-ray spectroscopy to study low-lying spectral and decay properties of heavy-neutron-rich nuclei around A∼190 produced following the relativistic projectile fragmentation of 208Pb primary beam. The response of the RISING active stopper detector is demonstrated for both the implantation of heavy secondary fragments and in-situ decay of beta-particles. Beta-delayed gamma-ray spectroscopy following decays of the neutron-rich nucleus 194Re is presented to demonstrate the experimental performance of the set-up. The resulting information inferred from excited states in the W and Os daughter nuclei is compared with results from Skyrme Hartree-Fock predictions of the evolution of nuclear shape. [ABSTRACT FROM AUTHOR]

At the time neon burning is activated in massive stars, large amounts of 25Mg and 26Mg have been accumulated from the previous evolutionary phases. In particular, at typical temperatures for neon shell burning, the reactions 25Mg(α,n)28Si and 26Mg(α,n)29Si become efficient providing additional neutron fluxes and affecting the nucleosynthesis distribution. Good knowledge of the reaction rates is required to study their effect on nucleosynthesis during neon shell burning conditions (T9>=1.5, where T9 is the temperature in gigakelvin). At the Nuclear Science Laboratory, University of Notre Dame, IN, USA we developed a neutron detector to investigate the 25Mg(α,n)28Si and 26Mg(α,n)29Si reactions as possible neutron sources during neon shell burning. In the present paper we briefly describe the experimental procedures developed to measure those reactions. Finally, we discuss the impact of 25Mg(α,n)28Si and 26Mg(α,n)29Si on the s-process nucleosynthesis for the barium isotopes. [ABSTRACT FROM AUTHOR]

Estimation of cosmic-ray spectra in the atmosphere has been an essential issue in the evaluation of the aircrew doses. We therefore developed an analytical model that can predict the terrestrial neutron, proton, He nucleus, muon, electron, positron and photon spectra at altitudes below 20 km, based on the Monte Carlo simulation results of cosmic-ray propagation in the atmosphere performed by the PHITS code. The model was designated PARMA. In order to examine the accuracy of PARMA in terms of the neutron dose estimation, we measured the neutron dose rates at the altitudes between 20 to 10400 m, using our developed dose monitor DARWIN mounted on an aircraft. Excellent agreement was observed between the measured dose rates and the corresponding data calculated by PARMA coupled with the fluence-to-dose conversion coefficients, indicating the applicability of the model to be utilized in the route-dose calculation. [ABSTRACT FROM AUTHOR]

The azimuthal asymmetry of hadrons in the semi-inclusive process e+p → e+h+X is studied in deep inelastic scattering at HERA. A measurement of the dijet cross section with a leading neutron is also reported, the PT2 distribution of the leading neutron is investigated. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The current version of the European Activation File is EAF-2003. This contains various libraries of nuclear data required for activation calculations. An important component is the neutron-induced cross-section library. Plans to expose fusion components to high neutron fluxes include the IFMIF materials testing facility. This accelerator-based device will produce neutrons with a high-energy tail up to about 55 MeV. In order to carry out activation calculations on materials exposed to such neutrons it is necessary to extend the energy range of the cross-section library. Work on extending the energy range to 60 MeV is nearing completion. A test version (EAF-2004) was produced at the end of 2003 showing the feasibility of the chosen approach. This library required calculated data to extend the existing data from 20–60 MeV and to enlarge it with new classes of reactions with high thresholds. A summary of the new library EAF-2005, which is under development and is planned for distribution at the beginning of 2005, is given. The other files in EAF-2005 are briefly described; these cover cross-section uncertainty information and decay data. Both these have been extended beyond the current version to allow activation calculations at energies up to 60 MeV. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The analysis code SAMMY is widely used for parameterization and understanding of neutron- and charged-particle-induced cross-section data. This report describes advances made in the development of the code: An overview of the main features of SAMMY is presented, with emphasis on options recently added to the code. Among the new options are an energy-dependent direct-capture component for capture cross sections, a crystal-lattice model for Doppler broadening, improvements in the fitting procedure to incorporate more of the experimental uncertainties and covariances, streamlined input, and enhanced ENDF-related capabilities. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The space nuclear reactors being considered to support the Jupiter Icy Moons Orbiter (JIMO-1) mission-1 sometime in the next decade are compact and fast spectrum with void fractions ranging from 20–40%. In order to secure launch approval, it has to be demonstrated that these reactors will remain sufficiently subcritical when submerged in water or wet sand and subsequently flooded with water, following a launch abort accident. The resulting shift in the neutron spectrum towards thermal increases reactivity, potentially making the reactors supercritical. Incorporating “Spectral Shift Absorbers” (or SSAs), elements such as boron, europium, gadolinium or rhenium, which have significantly higher absorption cross-sections for thermal versus fast neutrons, can offset the reactivity increase. It has always been the assumption that the worst-case submersion accident is with a fully flooded reactor; however, this work shows that, depending on the type and amount of SSA in the reactor, a submerged but unflooded reactor core could be more reactive, raising a safety concern. This condition, referred to as “reactivity inversion”, is investigated for the following SSA elements: boron, boron-10, samarium-149, europium, europium-151, gadolinium, gadolinium-155, gadolinium-157 and rhenium, by varying the ratio of SSA to fissile atoms in the reactor. The effect of placing a coating of SSA material on the outside of the reactor vessel is also investigated. Gadolinium-157 is the most effective SSA material investigated as a core additive, yielding the greatest increase in the safety worth of a submerged space reactor with a comparatively small decrease in excess reactivity. Samarium-149 yields a similar increase in safety worth, but with a much larger decrease in excess reactivity. Natural europium and gadolinium are also promising: however, the decrease in the excess reactivity is greater with europium than with gadolinium. Boron and boron-10 are not particularly attractive as core additives, but boron-10 yields the greatest benefit as a coating. Rhenium is useful only if the desired safety worth is small (< $3) and at a significant mass penalty. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The paper reports on experimental developments for studies of decays of proton radioactive nuclei on the Argonne Fragment Mass Analyzer. The results illustrate that there is a clear proton decay rate sensitivity to the unpaired neutron orbital in highly deformed odd-odd nuclei consistent with the Influential Spectator Model of Ferreira and Maglione. No such sensitivity is observed for the proton decay rates of spherical odd-odd nuclei studied here. The first ever study of proton decay from a nucleus, 135Tb, produced via 1p6n fusion evaporation is also reported. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]

The total kinetic energy (TKE) release in the fast neutron-induced fission of various actinide nuclei was measured for neutron energies for En =2.6-100 MeV at the Weapons Neutron Research facility of the Los Alamos National Laboratory. The data are compared to the GEF model of the fission process. The variances of the TKE distributions appear to decrease with increasing Z and A of the fissioning systems. [ABSTRACT FROM AUTHOR]

A laboratory has been constructed by the TEXONO Collaboration at the Kuo-Sheng Reactor Power Plant in Taiwan to study low energy neutrino physics. A limit on the neutrino magnetic moment of μν(νe) < 7.2 × 10-11 μB at 90% confidence level has been achieved from measurements with a high-purity germanium detector, as well as the electron neutrinos (νe) produced from nuclear power reactors has been studied. Other research program at Kuo-Sheng are surveyed. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Thin, isotopic 14C foils are of great interest to the nuclear physics community as neutron-rich targets. Historically, these foils have been extremely difficult to prepare and an effort is underway to make them readily available. The stock material of 14C available at Argonne contains a number of oxide impurities (SiO2, MgO, and Al2O3), which affect the composition and stability of the fabricated foil. A simple, robust method was developed (using natC as a surrogate) to purify the 14C material while minimizing loss and potential spread of the material. Thin foils were fabricated using the purified carbon, the unpurified carbon/oxide mix, and purchased high-purity carbon powder. SEM and EDS of the resulting foils was performed and the efficacy of this purification method was demonstrated. [ABSTRACT FROM AUTHOR]