Search

The study of collisions around the Coulomb barrier induced by halo and/or weakly bound nuclei has been the object of many publications in the last years, since the peculiar structure of such nuclei can strongly affect the reaction dynamics. In this paper we will summarize some results on the above topic obtained by our group at INFN-LNS Catania. Results concerning the study of elastic scattering and different reaction mechanisms in collisions induced by the halo nuclei 11Be and 6He and by the weakly bound stable nuclei 6,7Li on a 64Zn target, at energies around the Coulomb barrier, will be presented. The conclusions of our studies will be compared with the ones of other authors, in order to show if clear systematic conclusions can be drawn from the different papers published in the literature so far. [ABSTRACT FROM AUTHOR]

Collisions of asymmetric nuclei (Cu+Au) differ essentially from the case of symmetric nuclei (Cu+Cu, Au+Au) collisions in the geometry of overlap region. This leads to a number of consequences, which provide more absolute and accurate information about fundamental properties of matter under extreme conditions. Nuclear modification factors for π-mesons in Cu+Au interactions at 200 GeV were measured in PHENIX Experiment at RHIC. New experimental data on measurement of flows of different order (v1, v2) for light hadrons in Cu+Au interactions at 200 GeV will be discussed in this paper. [ABSTRACT FROM AUTHOR]

Laudatio in honor of Dr. Miguel Ángel Pérez Angón, co-recipient of the 2008 Medal of the Division of Particles and Fields of the Mexican Physical Society [ABSTRACT FROM AUTHOR]

We discuss the status-of-the-art in the development of the off-line reconstruction of ionizing event in LAr-TPC. An overview, from “easy” to progressively more complicated topologies reconstruction is presented. Outcomes from the reconstruction of events collected during the exposure of the ICARUS T600 LAr-TPC to cosmic rays and the exposure of the ArgoNeuT LAr-TPC to low energy neutrinos provides the main subject of this paper. [ABSTRACT FROM AUTHOR]

This paper presents an overview of the neutrino charged-current deep inelastic scattering measurements published in the last five years. Results from NuTeV, CHORUS, MINOS and NOMAD are discussed. Total neutrino cross section and structure functions results are compared. [ABSTRACT FROM AUTHOR]

One of the main goals of the Tevatron RunII is to look for any hints for new physics. At D0, the range of searches for new physics signals is large. A few of these analyzes are discussed in this paper. [ABSTRACT FROM AUTHOR]

It is still a mystery why the Standard Model as we know it has only three families. At new high energy colliders it is worthwhile to search for a new additional family which obviously would have a heavy neutrino to avoid the LEP bounds. This paper discusses new studies made with the CMS detector for the search of new heavy b-like quarks in several different decay modes and for different possible mass regions. These studies are based on detailed detector simulation, including all Standard Model backgrounds. Particular emphasis is given to possible early discoveries, i.e. with 100 pb-1 or less. Projected 95% CL exclusion limits as a function of luminosity are presented as well. [ABSTRACT FROM AUTHOR]

A green laser (CW, 532 nm) based Fabry-Pérot cavity for high precision Compton Polarimetry is under development in Hall A of the Jefferson Laboratory. In this paper, we present the principle and the preliminary studies for our test cavity. [ABSTRACT FROM AUTHOR]

NLO QCD analysis of the world unpolarized and polarized deep-inelastic experimental data were performed in order to extract the ΛQCD and αs(Mz2). In this paper we use the ΛQCD which can be obtain from the polarized deeply inelastic scattering. By having the ΛQCD, one can determine the αs(Mz2). We compare all of different NLO measurements of the strong coupling constant in unpolarized and polarized deeply inelastic scattering. [ABSTRACT FROM AUTHOR]

The National Ignition Facility, the world's largest laser, is scheduled for completion in 2009, and will beginning performing experiments in basic science about the same time. NIF is expected to produce temperatures and densities well above those at the core of the Sun, so it appears to have the capability to study thermally averaged cross sections involving a variety of light nuclei, many of which are of interest to nuclear astrophysics. Most of these reactions are affected, in some instances dominated, by compound nuclear states. This paper first describes some of the basic parameters of NIF, then discusses several experiments in nuclear astrophysics, some of which might be performed at NIF, and some of which could not be performed at any other facility in existence. [ABSTRACT FROM AUTHOR]

An accurate value of the nuclear resonance spacing is crucial for determination of level densities. Level densities are key input for the calculation of nuclear reaction rates and cross sections. This paper discusses various effects that can adversely impact the average level spacing, with special emphasis on the issue of quantum number assignment. The most striking property of spacings of resonances with the same quantum number is level repulsion. We investigate how a simple test based on level repulsion can be used in the identification of spin misassignment and provide new experimental verification of the proposed test. Proton resonances obtained in the 44Ca+p reaction are used as an example. In addition, s-wave neutron resonances in the 238U+n reaction are considered. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The present report gives a detailed analysis of experimental works and a review of alpha-induced reaction cross-section data of five alpha-alpha nuclei, Mg-24, Si-28, S-32, Ar-36 and Ca-40, for incident alpha energy up to 20 MeV. Alpha-induced reactions play an important role in the helium burning stage of stars, novae, and supernovae. These reactions are basic to the CNO and Al-Mg cycles, and also to the production of neutrons producing S and R processes occurring in stars. Thus, the availability of cross-section data for these reactions is a prime need for the study of nuclear interactions taking place in stars. These data have been compiled as part of an international collaboration, funded in part by the Civilian Research & Development Foundation, and are available in the EXFOR databases. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

High-precision data in three-nucleon scattering processes and state-of-the-art few-body calculations have contributed significantly to our present understanding of three-nucleon forces at intermediate energies. This paper discusses in more detail the pd→3Heγ reaction as a probe for electromagnetic currents in the three-nucleon system. Experimental data are reviewed and interpreted by a comparison with Faddeev and coupled-channel calculations from the Bochum-Cracow and Hanover theory groups, respectively. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

This paper described current progress of nuclear astrophysical studies using the unstable ion beam facility GIRAFFE. We measured the angular distributions for some low energy reactions, such as 11C(d,n)12N, 8Li(d,p)9Li and 17F(d,n)18Ne in inverse kinematics, and indirectly derived the astrophysical S-factors or reaction rates of 11C(p,γ)12N, 8Li(n,γ)9Li, 8B(p,γ)9C at astrophysically relevant energies. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Alpha channeling in tokamaks is speculative, but also extraordinarily attractive. Waves that can accomplish this effect have been identified. Key aspects of the theory now enjoy experimental confirmation. This paper will review the elementary processes of wave-particle interactions in plasma that underlie the alpha channeling effect. [ABSTRACT FROM AUTHOR]

Orbital debris in low Earth orbit (LEO) are now sufficiently dense that the use of LEO space is threatened by runaway collisional cascading. A problem predicted more than thirty years ago, the threat from debris larger than about 1cm demands serious attention. A promising proposed solution uses a high power pulsed laser system on the Earth to make plasma jets on the objects, slowing them slightly, and causing them to re-enter and burn up in the atmosphere. In this paper, we reassess this approach in light of recent advances in low-cost, light-weight segmented design for large mirrors, calculations of laser-induced orbit changes and in design of repetitive, multi-kilojoule lasers, that build on inertial fusion research. These advances now suggest that laser orbital debris removal (LODR) is the most costeffective way to mitigate the debris problem. No other solutions have been proposed that address the whole problem of large and small debris. A LODR system will have multiple uses beyond debris removal. International cooperation will be essential for building and operating such a system. [ABSTRACT FROM AUTHOR]

The discovery of a new particle in the Higgs searches being prepared for LHC will not guarantee that the Standard Model Higgs boson has been seen. This paper discusses the possibilities for measuring the spin, parity and couplings of the particle, under the assumption that it does in fact behave like the Standard Model Higgs. The key question, which cannot alas be answered, is: if it looks like a dog, and barks like a dog, how much of the DNA must we analyse to be sure that it is a dog? [ABSTRACT FROM AUTHOR]

Several Standard Model processes contain electrons in the final state. Also, many signatures expected from physics beyond the Standard Model include one or more electrons. This paper describes the electron reconstruction along with some of the identification criteria used in the ATLAS detector. The expected performance at the start-up of the experiment are also presented. [ABSTRACT FROM AUTHOR]

In this paper we briefly discuss the estimation of uncertainties in QCD backgrounds to searches for Supersymmetry under development by the ATLAS collaboration. [ABSTRACT FROM AUTHOR]

The performance of the ALICE detector in searches for new heavy stable charged particles in pp collisions is discussed in this paper. Gluino R-hadron was chosen as an example of a candidate, and cross sections and kinematic properties were obtained from PYTHIA simulations for various gluino masses (100–500 GeV/c2). Detector response simulations for R-hadrons in the TPC acceptance (|η|<1) were performed for 100 GeV/c2 R-hadron mass. [ABSTRACT FROM AUTHOR]

In this paper an updated GEANT-4 simulation toolkit is presented describing the interactions in matter of heavy hadrons containing long-lived squarks and gluinos. Generic signatures are derived that are applicable at the Large Hadron Collider, and the problem of theoretical uncertainties arising from model dependence is addressed. For a more detailed description of the assumptions and techniques used, the reader is referred to ref. [1]. [ABSTRACT FROM AUTHOR]

We describe plans for a search for long-lived particles which will become stopped by the CMS detector. We will look for the subsequent decay of these particles during time intervals where there are no pp collisions in CMS: during gaps between crossings in the LHC beam structure, and during inter-fill periods between the beam being dumped and re-injection. Such long living particles decays will be recorded with dedicated calorimeter triggers. For models predicting these particles, such as split-susy gluinos, the large cross-section combined with good stopping power of CMS, yields a significant number of triggerable decays. If LHC instantaneous luminosity approaches 1032 cm-2s-1 in 2009–10, 5σ significance can be established in a matter of days, since these decays occur on top of a negligible background. Due to limited size, this paper concentrates on main idea and expected results. More details are available in https://twiki.cern.ch/twiki/bin/view/CMS/PhysicsResults. [ABSTRACT FROM AUTHOR]

The Large Hadron Collider, designed to collide protons and ions at unprecedented center-of-mass energies, will offer new opportunities for the study of the properties of strongly interacting matter at high energy density and temperature. Such complex investigation will be carried out by three experiments, ALICE, explicitly dedicated to this purpose, ATLAS and CMS, through the analysis of several observables. Among them, an important role is expected to be played by heavy-flavor and heavy quarkonium state measurements. The motivations for measuring open and hidden charm and beauty will be provided in this paper, together with a discussion on the expected performances of the experiments, based on the results of Monte Carlo simulations for a selection of physics channels. [ABSTRACT FROM AUTHOR]

The HIγS facility is capable of providing intense beams of linearly and circularly polarized gamma rays, at energies from 2 MeV and soon to extend up to 100 MeV. This paper describes a Compton scattering program which has been designed to measure the electric and magnetic polarizabilities of the proton and the neutron, as well as the spin-polarizabilities of both. Linearly polarized beams will be used to measure the electric and magnetic polarizabilities of the proton, while Compton scattering from the deuteron will lead to values of these fundamental quantities for the neutron. Circularly polarized beams and polarized proton and 3He targets will be used to extract the four spin-polarizabilities of the nucleons with accuracies ranging from 5-to-25%. These values will be compared to the predictions of Chiral Perturbation Theory and anticipated results from Lattice QCD calculations. [ABSTRACT FROM AUTHOR]

In this paper a concise overview of recent results concerning the properties of ion-particle interaction and the ion drag force in complex (dusty) plasmas is presented. Two main theoretical approaches to calculate the ion drag force—binary collision and linear plasma response formalisms are discussed. When possible, theoretical results are compared with the results from experiments and numerical simulations. [ABSTRACT FROM AUTHOR]

The ERLP energy recovery linac prototype at Daresbury Laboratory has been rebranded, and is now called ALICE (Accelerators and Lasers In Combined Experiments). This paper gives an overview of the project and its status, outlines some of the challenges experienced during the commissioning of the photoinjector and superconducting accelerating systems, and presents our photoinjector gun commissioning results. An outline is given of the planned photon science program for ALICE, and its under-pinning role in the EMMA NS-FFAG project. [ABSTRACT FROM AUTHOR]

ALICE—Accelerators and Lasers in Combined Experiments—is a relatively new accelerator built at Daresbury Laboratory that will demonstrate the process of energy recovery by the end of 2008. The project is a research facility to develop the technology required to build a New Light Source (NLS) in the UK. This paper details the current ALICE photoinjector design and highlights the limitations before focusing on a photoinjector upgrade. The key component of the upgrade is a three-stage extreme high vacuum load-lock system that will be incorporated into the ALICE photoinjector in 2010. The load-lock system has de facto become a standard component of a type III–V semiconductor photocathode injector and comprises: 1) loading chamber to allow new photocathodes to be introduced, 2) cleaning chamber for atomic hydrogen cleaning of the photocathodes and, 3) a preparation and activation chamber where the photocathodes will be activated to the NEA state ready for use on the ALICE accelerator. Once commissioned the load-lock system will allow rapid transfer of photocathodes between the load-lock system and the ALICE photoinjector whilst maintaining the integrity of the vacuum system and providing many other benefits. The new load-lock system will not only remove the problems with the existing set-up, it will also permit a new vacuum chamber to be designed for the gun itself. This new design will also aim to improve vacuum performance by addressing some of the major vacuum associated problems ALICE has encountered in the past 2 years. [ABSTRACT FROM AUTHOR]

Ion Beam Analysis (IBA) techniques are a powerful tool to study atmospheric aerosol composition, since they are quantitative, multi-elemental, fast, high-sensitivity and non-destructive analytical methods. At the 3 MV Tandetron accelerator of the LABEC laboratory of INFN in Florence an external beam facility is fully dedicated to measurements of elemental composition of atmospheric aerosols. All the elements with Z>10 are simultaneously detectable by Particle Induced X-ray Emission (PIXE) in few minutes of beam time, including several important tracers of peculiar aerosol sources and potentially harmful elements, with minimum detection limits ranging between 1 and 10 ng/m3. Light elements (H, C, N, O), which are the main aerosol constituents, can be detected by means of in-vacuum Particle Elastic Scattering Analysis (PESA). The application of both PIXE and PESA allows a complete mass reconstruction of aerosol samples. Since these methods are non-destructive, it is possible to apply complementary techniques, like Ion Chromatography, on the same samples, obtaining information, for example, on the chemical composition. Scanning possibility may also be very useful, allowing time trend reconstruction by the analysis of time-sequence aerosol deposits collected by continuous samplers. Using a two-stage “streaker” sampler the concentration time series of all the elements with Z>10 can be measured with hourly resolution. In this paper the peculiarity of these methods will be highlighted and the results of recent campaigns will be shown, including the application of IBA techniques to aerosol daily and hourly samples, collected in urban and industrial areas. [ABSTRACT FROM AUTHOR]

The field of ultrarelativistic heavy ion collisions is today a flourishing activity both on the experimental and on the theoretical side. Although the theoretical justifications to study these collisions was given already more than three decades ago and the experimental studies have a history of more than 25 years we are still very much in the dark as to the details of the processes and of the characteristics of the matter created in collisions. Increasing the energy of collisions has brought new insights but has also resulted with new challenges. In the present paper I will try from a personal perspective to report on the answers we have collected and on the problems we are faced with. The account is partial, taking into account that it is impossible to render justice to every aspect of the field. [ABSTRACT FROM AUTHOR]

The growing body of anomalies in new energy, low energy nuclear reactions, astrophysics, atomic physics, and entanglement, combined with the failure of the Standard Model and string theory to predict many of the most basic fundamental phenomena, all point to a need for major new paradigms. Not Band-Aids, but revolutionary new ways of conceptualizing physics, in the spirit of Thomas Kuhn’s The Structure of Scientific Revolutions. This paper identifies a number of long-held, but unproven assumptions currently being challenged by an increasing number of alternative scientists. Two common themes, both with venerable histories, keep recurring in the many alternative theories being proposed: (1) Mach’s Principle, and (2) toroidal, vortex particles. Matter-based Mach’s Principle differs from both space-based universal frames and observer-based Einsteinian relativity. Toroidal particles, in addition to explaining electron spin and the fundamental constants, satisfy the basic requirement of Gauss’s misunderstood B Law, that motion itself circulates. Though a comprehensive theory is beyond the scope of this paper, it will suggest alternatives to the long list of assumptions in context. [ABSTRACT FROM AUTHOR]

In this paper we describe the capabilities of the MINERνA experiment for the measurement of neutrino-nucleus coherent scattering. [ABSTRACT FROM AUTHOR]

The LHC will deliver unexplored energy regimes for proton-proton and heavy-ion collisions. As shown by the RHIC experiments, particle identification over a large momentum range is essential to disentangle physics processes, especially in the intermediate pT(1T<5 GeV/c) region. The novel design of the High-Momentum Particle Identification Detector (HMPID), based on large surface CsI photocathodes, is able to identify π±, K±, p and p in the momentum region where bulk medium properties and hard scatterings interplay. Furthermore, measurement of resonance particles such as the [lowercase_phi_synonym]→K+K- could provide information on the system evolution. The HMPID layout and segmentation are optimized to study particle correlations at high momenta describing the early phase and the dynamical evolution of the collision. At LHC, the increased hard cross section will significantly be enhanced compared to RHIC. Identified leading particle correlations and jet reconstruction via Deterministic Annealing can address jet quenching and detailed measurements of jet properties. In this paper, we present these selected topics from the possible HMPID contributions to the physics goals of LHC. [ABSTRACT FROM AUTHOR]

This paper presents a study of the usability of the Coulomb cut-off potential for the calculation of bound-free and free-free cross sections. It covers the condition in dense plasma where there is no good theory that covers the optical properties of dense plasma. The presented quantum mechanical model has given a good agreement with the experimental data. The ideas for further development of the presented calculations are shown. [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]

The study of reaction mechanisms in collisions induced by halo and/or weakly bound nuclei around the barrier has recently been the subject of many theoretical and experimental papers. Here we discuss our recent results concerning the study of the systems 13N+9Be and 6He+64Zn. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The multiparticle production results from A+A and p(p)+p collisions have been compared based on the number of nucleon participants and the number of constituent quark (parton) participants. In both normalizations, we observe that the charged particle densities in Au+Au and Cu+Cu collisions are similar for both √sNN = 62.4 and 200 GeV. This implies that in symmetric nucleus-nucleus collisions the charged particle density does not depend on the size of the two colliding nuclei but only on the collision energy. In the nucleon participants framework, the particle density at mid-rapidity as well as in the limiting fragmentation region from A+A collisions are higher than those of p(p)+p collisions at the same energy. Also the integrated total charged particle in A+A collisions as a function of number nucleon participants is higher than p(p)+p collisions at the same energy indicating that there is no smooth transition between peripheral A+A and nucleon-nucleon collisions. However, when the comparison is made in the constituent quarks framework, A+A and p(p)+p collisions exhibit a striking degree of agreement. The observations presented in this paper imply that the number of constituent quark pairs participating in the collision controls the particle production. One may therefore conjecture that the initial states A+A and p+p collisions are similar when the partonic considerations are used in normalization. Another interesting result is that there is an overall factorization of dNch/dη shapes as a function of collision centrality between Au+Au and Cu+Cu collisions at the same energy, √sNN = 200 GeV. [ABSTRACT FROM AUTHOR]

This paper presents the basic principles of medium energy ion scattering and of nuclear resonant reaction profiling, which at present constitute available techniques for near-surface elementary profiling with high depth resolution. The principles of ion energy loss are discussed at first, as they constitute the basic physical processes underlying the profiling techniques. Examples are presented and discussed, mainly concerning applications in the area of high-k replacement materials for silicon oxide/oxinitride in ULSI technology. The possibility of profiling elements with nano or subnanometric resolution is giving a significant contribution to solve many problems of research and development in MOS structures for advanced ULSI technology. © 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]

The Working Party on International Nuclear Data Cooperation represents a collaborative effort of major nuclear-reaction data-evaluation projects. The technical work is presently performed by 3 standing and 6 short-term subgroups. Among the most recent achievements are the establishment of ModLib (modular nuclear reaction code library), the development of a new version of neutron cross-section standards, and an effort to improve the 238U+n evaluation. The paper reviews achievements of the Working Party and outlines its future plans. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The internal conversion and electron-positron pair creation processes provide a versatile tool for investigating various aspects of the nuclear structure. The most recent calculations of Internal Conversion Coefficients, based on relativistic self-consistent Dirac-Fock calculations are widely regarded as the most accurate numerical results available today. The International Nuclear Structure and Decay Data Network has adopted the new conversion coefficients to replace the Hager and Seltzer, Rössel et al., and Band and Trzhaskovskaya tables. In this paper we report on the development of a new conversion electron data base and associated programs, which includes the new internal conversion coefficients tables, published in At. Data and Nucl. Data Tables 81, (2002) 1. Additional calculations have been carried out to extend the energy range, as well as improve the interpolation accuracy to obtain conversion coefficients in the 1-keV to 6000-keV region. Additional data tables have been compiled from published data to obtain values of electron-positron pair conversion coefficients and Ω(E0) electronic factors. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

This paper reports an evaluation work on the resolved resonance parameters of the α + 9Be reaction from 0 to 4 MeV performed with the SAMMY code. The use of the Reich-Moore approximation of the R matrix theory allows a definitive assessment of the magnitude of the (α,n) excitation function at zero degree by selecting the best data sets among the experiments available for the 13C compound nucleus. The by-product of this work is the generation of a full set of point wise integrated and differential 9Be(α,n)12C cross section data up to 4 MeV. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The new IRDF-2002 dosimetry cross-section library was completed by the IAEA in January 2004. A rigorous process was followed in the selection of the recommended dosimetry cross sections. The cross-section selection was followed with a consistency testing. This paper reports on the results of the consistency testing. All candidate selections passed the acceptance testing criteria and the library release is pending. Observations are made on areas that need improvement in the cross sections and in the scope of the consistency testing. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The characteristics of a Lead Slowing-Down Spectrometer (LSDS) installed at the Los Alamos Neutron Science Center (LANSCE) are presented in this paper. This instrument is designed to study neutron-induced fission on ultra small quantities of actinides, on the order of tens of nanograms or less. The measurements of the energy-time relation, energy resolution and neutron flux are compared to simulations performed with MCNPX. Results on neutron-induced fission of 235U and 239Pu with tens of micrograms and tens of nanograms, respectively, are presented. Finally, a digital filter designed to improve the detection of fission events at short time after the proton pulses is described. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Thin natural uranium targets were irradiated by a 660 MeV proton beam from the Phasotron accelerator at the Joint Institute for Nuclear Research in Dubna, Russia. Cross-sections of the formation of residual nuclei natU(p,xpyn)ZARes are determined by methods of gamma spectroscopy. Until now, 43 long-lived (T1/2 > 100 days) isotopes were observed and their cross-sections determined. More than 350 intermediate-lived (1 day < T1/2 < 100 days) and short-lived (T1/2 < 1 day) isotopes have been identified in the γ-spectra and many unanalyzed lines yet remain. Final results for 43 long-lived isotopes and upper cross-section limits for 27 long-lived isotopes are presented in this paper and compared with results by five different models. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The nuclear excitation by electron capture (NEEC) and nuclear excitation by electronic transition (NEET), and related de-excitation, are two important electromagnetic processes to modify the nuclear state populations. In this paper, we present, on one hand, an experiment accepted at GANIL (France) in September 2004 to measure the NEEC effect with a fully stripped 57Fe ion beam and, on the other hand, a complete calculation leading to the NEET rate of the first excited state of the 235U in a local thermodynamic equilibrium (LTE) plasma. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

It is now generally recognized that the Dirac equation is a viable alternative to the usual Schrödinger equation approach for analyzing nucleon-nucleus scattering data. This paper reviews the development of Dirac phenomenology, stressing how closely this development has been tied to experiment. In addition we discuss a new method for extracting neutron densities from intermediate energy elastic proton-nucleus scattering observables uses a global Dirac phenomenological (DP) approach based on the Relativistic Impulse Approximation (RIA). Data sets for 40Ca, 48Ca and 208Pb in the energy range from 500 MeV to 1040 MeV are used. The global fits reproducing the data well and this allows one to obtain the proton and neutron densities, their root-mean-square radii, Rp and Rn, and the neutron skin thickness, Sn = Rn - Rp. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The stellar (n,γ) cross sections of the Ne isotopes are important for a number of astrophysical quests, i.e., for the interpretation of abundance patterns in presolar material or with respect to the s-process neutron balance in red giant stars. This paper presents resonance studies of experimental data in the keV range, which had not been fully analyzed before. The analyses were carried out with the R-matrix code SAMMY including the consistent treatment of possible interferences in the resonant part. With these results the resonant part of the neon cross sections could be determined. If the component due to direct radiative capture is normalized at thermal neutron energies, one finds that the stellar rates had been grossly overestimated. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The ion injector chain for the LHC has to be adapted and modified to reach the design beam parameters. Up to now an ECR4 delivered the ion beam for the SPS fixed target physics programme. This source will be replaced by a higher intensity source to produce the Pb27+ ion current required to fill the Low Energy Ion Ring (LEIR). The new ion source will be based on the Grenoble Test Source which was itself based on empirical scaling laws derived from the Framework 5 “Innovative ECRIS” collaboration. This paper will describe the design principle, the commissioning timetable and the present status of the source development. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

This paper presents recent results from the BRAHMS experiment at RHIC; including results on particle production in rapidity space extending from y=0 to y ∼ 3 and on the transverse momentum distribution of fully identified charged particles. These results were obtained from the 5% most central Au-au collisions recorded during RHIC Run-2 at √sNN = 200 GeV. [ABSTRACT FROM AUTHOR]