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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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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 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]