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Experiments based on the isomer-spectroscopy method were performed using the secondary beam line at RCNP, Osaka University. Recently, a new γ-ray spectroscopy method was established using fusion reaction induced by low-energy RI beam. This method enables us to study high-spin states of nuclei in wider mass region where it is difficult to populate them by using the combination of stable beams and stable targets. This method works well although low production of nuclei, because (1) the combination of beams and targets can be selected with large-reaction cross section and (2) high-S/N measurement can be performed by the event-by-event detection to select the events correlated with RI beam, which reduces background γ rays, competing with γ rays emitted from fusion products. As the first step, high-spin states of 142Pr were studied using fusion reaction induced by low-energy 17N RI beam. Large cross section was obtained by the 130Te(17N,5n) reaction with 4.9 MeV/u 17N beam. Event selection, which was carried out by the event-by-event detection with low-beam intensity of 2×104 pps, enables high-S/N measurement. [ABSTRACT FROM AUTHOR]

Abstract: A semi-thick target has been used to measure the stopping power for recoils, produced in heavy ion induced reactions, by -ray lineshape analysis. The target thickness has been chosen such that the recoils are partially slowed down in the target and subsequently escape into vacuum. For transitions deexciting long-lived states the Doppler lineshape then depends only on the stopping power. Stopping-power parameters have been determined for Pm, Sm and Nd nuclei in Cd. The results for the electronic stopping power agree within uncertainties with the predictions of the Lindhard, Scharff and Schiøtt theory. The nuclear stopping power can be well described in the framework of the Ziegler, Biersack and Littmark parameterization using the software package Stopping and Range of Ions in Matter (SRIM)2006. [Copyright &y& Elsevier]

Abstract: A detailed, universal simulation tool for the Recoil Distance Method lifetime measurements at the National Superconducting Cyclotron Laboratory (NSCL) is presented. The measurements are made with the Köln-NSCL plunger-SeGA setup and utilize fast, secondary beams of exotic nuclei provided by the Coupled Cyclotron Facility and the A1900 fragment separator. The simulation tool, built upon GEANT4 and Root toolkits, incorporates all relevant aspects of a plunger experiment. The tool is applied in two ways. First, to aid in the design of new experiments by facilitating the choice of optimal experimental conditions. Second, to aid in off-line analysis of the experimental data and in particular to deduce the lifetime by comparison of experimental and simulated peak shapes in the -ray energy spectra. All the important features of the simulation tool are described, followed by examples of the application of the tool in the cases of real experiments completed or proposed at NSCL. [Copyright &y& Elsevier]

Abstract: We propose to study the impact of gate width selection on -ray spectrum parameters such as peak-to-background ratio and statistics. We will approach this study on both theoretical and experimental point of view. Starting from the results of this preliminary study a new method of background subtraction has been elaborated. It is designed to remove efficiently contamination and continuum component in -ray spectrum. These works will be illustrated more specifically in the case of superdeformation for the 151Tb nucleus. [Copyright &y& Elsevier]

Abstract: The 3 MV Pelletron tandem accelerator MaRPel (Material Research Pelletron) of the II. Physikalisches Institut in Göttingen is equipped with a low-level target station for applying the Resonant Nuclear Reaction Analysis technique. This combination allows high-resolution hydrogen depth distribution profiling using a15N beam with an energy higher than 6.385 MeV, which is the resonance energy of the1H(15N,α γ)12C nuclear reaction. The installed AMSEL-steerers are used for an easy variation of the beam energy and a computer-controlled automated measurement of depth profiles. Here, the experimental set-up is described and the strategy of the energy calibration of MaRPel and the AMSEL-steerers is explained. The resolution and sensitivity of hydrogen depth profiling are presented together with some measured profiles as examples for possible applications of this analytic tool. [Copyright &y& Elsevier]

Abstract: New inelastic neutron scattering data for ErFe2Si2 and Mössbauer spectra for TmFe2Si2 are presented. These data are analysed in terms of the crystal field acting at the rare earth site and new crystal field parameters are presented. The new crystal field parameters are compared with previous parameters to show the systematics associated with a change in transition metal. [Copyright &y& Elsevier]

Abstract: A new charge-sensitive preamplifier for High Purity Germanium -ray detectors has been built and tested. It comprises an over-load recovery device that reduces the dead time brought about by hits of energetic particles. The amplitude of the large signals is reconstructed from Time-Over-Threshold measurements performed along the reset transients. Using such a technology an extremely wide energy range of 10keV to 30MeV, or 70dB, is obtained. With a count rate of 6kHz a resolution of 1.1keV fwhm is obtained on the 152Eu 122keV line and of ∼5 perthousand on pulser lines in the energy range of 5–30MeV. [Copyright &y& Elsevier]

Abstract: A high-efficiency evaporation-residue counter (named HERCULES) has been designed and constructed. It consists of 64 thin fast-plastic scintillators arranged in four rings covering an angular range of 3.1– at 30.9cm from the target. The device design has been optimized for use with GAMMASPHERE. Evaporation residues are well separated from elastic scattering, fission events, and other undesirable reaction debris by time-of-flight and pulse-height analysis. Each detector element can operate at rates up to 0.5MHz with signal recovery in about 10ns. The geometry, construction, light-output characteristics, stability of the measured quantities, associated electronics, and in-beam performance of the device are described. For energy-degraded fission fragments with kinetic energies of less than 45MeV, it is found that (1) the dependence of the pulse height disappears and (2) the light output per unit energy increases with decreasing energy. For evaporation residues from two reactions, in which the evaporation channels dominate and in which the residue cross-section is about 100 times smaller than the fission cross-section, angular distributions and sample -ray spectra are shown. [Copyright &y& Elsevier]

We have performed a search for Sarin, a chemical warfare agent, in luggage-sized sealed containers in order to illustrate how effectively and quickly a search could be conducted in a fixed installation at airports, embassies, government buildings, military installations, and other public areas. A portable neutron generator and a Californium source were used, generating up to 108 neutrons per second, that penetrate into a container and are capable of exciting a sample in a period of approximately 10 s, to produce enough γ radiation that target elements within the sample can be identified. In the vast majority of cases, there is no chemical agent present, so the question becomes how long to search. We show results of tests for sensitivity of this technique as a function of time. We have also developed background or typical samples with no chemical agent present to estimate the false positive rate for this technique. [Copyright &y& Elsevier]

CLAIRE is a balloon-borne telescope dedicated to validating the concept of a crystal diffraction lens for nuclear astrophysics. For the first time, focusing γ-rays enters into the domain of the high energy astrophysics. This represents a breakthrough in γ-ray instrumentation, and will allow unprecedent sensitivities. CLAIRE''s first flights occurred on June 15 2000 and on June 14 2001. Here we present its performance during the two flights in terms of pointing accuracy, background noise and estimated efficiency of the lens. [Copyright &y& Elsevier]

Radioactive atoms have been used in solid-state physics and in material science for many decades. Besides their classical application as tracer for diffusion studies, nuclear techniques such as Mößbauer spectroscopy, perturbed angular correlation, β-NMR, and emission channeling have used nuclear properties (via hyperfine interactions or emitted α- or β-particles) to gain microscopical information on the structural and dynamical properties of solids. During the last decade, the availability of many different radioactive isotopes as a clean ion beam at ISOL facilities like ISOLDE/CERN has triggered a new era involving methods sensitive for the optical and electronic properties of solids, especially in the field of semiconductor physics. Extremely sensitive spectroscopic techniques like deep-level transient spectroscopy (DLTS), photoluminescence (PL), and Hall effect gain a new quality by using radioactive isotopes: Due to their decay the chemical origin of an observed electronic and optical behavior of a specific defect or dopant can be unambiguously identified. This review will briefly introduce the experimental techniques used and browse through the ongoing experiments in solid-state physics using radioactive ion beams demonstrating the wide variety of problems under study involving bulk properties, surfaces and interfaces in many different systems like semiconductors, superconductors, magnetic systems, metals and ceramics. [ABSTRACT FROM AUTHOR]

Hyperfine interactions observed at isomeric states of radioactive probe nuclei are used as a tool for solid-state investigations. This method is sensitive to atomic-scale properties. In recent years surface and interface investigations using radioactive probes delivered many results which can hardly be achieved by any other method. Several groups, e.g., from Konstanz, Leuven, Groningen, Aarhus, Uppsala, Tel Aviv, Pennsylvania, contributed to this field. Our group studies magnetic properties at surfaces and interfaces performing perturbed angular correlation (PAC) measurements in the UHV chamber ASPIC (Apparatus for Surface Physics and Interfaces at CERN). We take advantage of the enhanced variety of PAC probes delivered by the on-line mass separator ISOLDE. First, we report on measurements of magnetic hyperfine fields ( Bhf) at Se adatoms on a ferromagnetic substrate using 77Se as a PAC probe. The investigation of induced magnetic interactions in nonmagnetic materials is a further subject of our studies. Here the nonmagnetic 4 d element Pd is investigated, when it is in contact with ferromagnetic nickel. An outlook will be given on studies to be done in the future. The experiments were performed at the HMI, Berlin, and at CERN, Geneva. [ABSTRACT FROM AUTHOR]

The decay of the neutron–rich isotope 216Bi, produced by proton–induced spallation at the PS Booster–ISOLDE facility, was investigated by β-γγ, αγ coincidence and spectrum-multiscaling measurements. A new method for reducing isobaric contamination enabled to cover the unknown region “east” of 208Pb for the isobaric chain A=216. The half-life of the β decay of 216Bi was found as T1/2= 135 ± 5 s. Its decay scheme was extended and the possible shell model configurations are proposed. [ABSTRACT FROM AUTHOR]

This work demonstrates the feasibility of in-beam γ-spectroscopy employing radioactive ion beam species at relativistic energies of E = 210 ∼ 280 A· MeV. Neutron-rich nuclei below 48Ca with neutron number between the two magic numbers 20 and 28 have been investigated. Using a Pb target, single step inelastic excitation originating mainly from Coulomb interaction takes place populating preferentially low-lying low-spin states and enabling the extraction of B(E2) values. On a C target, nucleon removal reactions are dominating and medium-spin states are populated thus offering spectroscopic information in neighboring nuclei. Cross sections of inelastic excitation are determined and compared to coupled-channels calculations. Two new states of the very neutron-rich nucleus 44Ar at 1.78(8) MeV and 2.61(16) MeV are deduced from γ-transitions. [ABSTRACT FROM AUTHOR]

The dependence of the HPGe-detector efficiency on its intrinsic and geometrical properties such as energy resolution, electronic noise, charge production statistics and effect of the rise time is considered. This study also includes the detector's sensitive volume. Efficiencies of a 0.55 cm planar and 46.3, 56.4 and 62.3 cm active volume of coaxial HPGe-detectors have been estimated for γ-ray energies from 50 to 1000 keV only, for a point source. Agreement has been found between the present calculated and published experimental efficiencies. [ABSTRACT FROM AUTHOR]

Copyright of Il Nuovo Cimento: A is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Il Nuovo Cimento: A is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The decay of 131Pm has been investigated by means of γ-ray spectroscopy. The 131Pm nuclei were produced by fusion-evaporation reaction of 106Cd(32S,3p4n) at the beam energy of 170 MeV. A helium-jet technique and a tape transport system were used to collect the activities and transfer them to a detecting position for X and γ rays measurement. Two γ rays of 185.0 and 220.0 keV were unambiguously identified to follow the β+ decay of 131Pm by results of X-γ and γ–γ coincidence. A growth-decay feature of the decay curve for 87.8 keV γ-ray of 131Nd confirmed the production of 131Pm nuclei. The half-life of 131Pm was measured to be 6.3 ± 0.8 s. A partial decay scheme of 131Pm is proposed on the basis of X-γ and γ–γ coincidence data in this experiment and the known structure information deduced from in-beam experiments of the daughter nucleus 131Nd. [ABSTRACT FROM AUTHOR]

Excited states in the Tz = -1 nucleus 44V have been observed for the first time. The states have been identified through recoil-γ-γ coincidences and comparison with analogue states in the mirror nucleus 44Sc. Mirror energy differences have been extracted and compared to state-of-the-art fp shell-model calculations which include charge symmetry breaking forces. [ABSTRACT FROM AUTHOR]