Search results for "accelerator"
showing 10 items of 1507 documents
Twin GEM-TPC prototype (HGB4) beam test at GSI and Jyväskylä : a development for the Super-FRS at FAIR
2017
The FAIR[1] facility is an international accelerator centre for research with ion and antiproton beams. It is being built at Darmstadt, Germany as an extension to the current GSI research institute. One major part of the facility will be the Super-FRS[2] separator, which will be include in phase one of the project construction. The NUSTAR experiments will benefit from the Super-FRS, which will deliver an unprecedented range of radioactive ion beams (RIB). These experiments will use beams of different energies and characteristics in three different branches; the high-energy which utilizes the RIB at relativistic energies 300-1500 MeV/u as created in the production process, the low-energy bra…
The SPEDE Spectrometer: Combined In-Beam γ-ray and Conversion Electron Spectroscopy with Radioactive Ion Beams
2015
The SPEDE spectrometer [1] aims to combine a silicon detector, for the detection of electrons, with the MINIBALL γ-ray detection array for in-beam studies employing radioactive ion beams at the HIE-ISOLDE facility at CERN. The setup will be primarily used for octupole collectivity [2] and shape coexistence studies [3, 4] in Coulomb excitation experiments. In the shape coexistence cases the transitions between states of the same spin and parity have enhanced E0 strength [5]. Additionally the 0→0 transitions, typically present in nuclei exhibiting shape coexistence [6], can only occur via E0 transitions, i.e. via internal conversion electron emission.
Beam cooler for low-energy radioactive ions
2001
Abstract An ion beam cooler for mass-separated radioactive ion beams has been developed and tested at the IGISOL-type mass separator facility. Technical description and characteristic properties are presented. An energy spread below 1 eV and transmission efficiency of 60% were measured.
Investigation of heavy ion produced defect structures in insulators by small angle scattering
1985
Fast heavy ions produce stable defects in most dielectrica. As examples mica, Polyethylenterephtalat and Polystyrol were irradiated with Ar, Ni, Kr, Xe and U ions in an energy range from 0.5 up to 20 MeV/u. The resulting defects were investigated by neutron and x-ray small-angle scattering. The ion beam supplied by the UNILAC accelerator at GSI Darmstadt is characterized by its small emittance, the well defined mass, charge and energy of the ions and their stochastical distribution in the phase space. In scattering experiments the system of scattering centers created by these ions causes a scattered intensity distribution which strongly depends on the orientation of the sample with respect …
TASISpec—A highly efficient multi-coincidence spectrometer for nuclear structure investigations of the heaviest nuclei
2010
TASISpec (TASCA in Small Image mode Spectroscopy) combines composite Ge- and Si-detectors for a new detector setup aimed towards multi-coincidence gamma -ray, X-ray, conversion electron, fission fragment, and a-particle spectroscopy of the heaviest nuclei. It exploits the TASCA separator's unique small image focal mode, i.e. the fact that evaporation residues produced in fusion-evaporation reactions can be focused into an area of less than 3 cm in diameter. This provides the possibility to pack detectors in very close geometry, resulting in an unprecedented detection efficiency of radioactive decays in prompt and delayed coincidence with implanted nuclei. Crown Copyright (C) 2010 Publis…
Reply to Douka et al: Critical evaluation of the Ksâr 'Akil chronologies
2015
Our paper (1) proposes a new chronology for Ksâr 'Akil based on 16 accelerator mass spectrometry (AMS) determinations on shells. To minimize the possibility of dating diagenetically compromised samples, we conducted amino acid racemization analyses on the intracrystalline proteins, oxygen isotope analysis, and geochemical characterization of all dated shells. Our calibrated radiocarbon ages fit well with existing Levantine chronologies, but are up to 4,000 y older than Douka et al.’s (2). Our paper explores several possibilities for this difference, whereas Douka et al. (3) provide alternative explanations. They accept our radiocarbon ages as correct but question our sample selection and Ba…
Laboratory disruption of scaled astrophysical outflows by a misaligned magnetic field
2021
The shaping of astrophysical outflows into bright, dense, and collimated jets due to magnetic pressure is here investigated using laboratory experiments. Here we look at the impact on jet collimation of a misalignment between the outflow, as it stems from the source, and the magnetic field. For small misalignments, a magnetic nozzle forms and redirects the outflow in a collimated jet. For growing misalignments, this nozzle becomes increasingly asymmetric, disrupting jet formation. Our results thus suggest outflow/magnetic field misalignment to be a plausible key process regulating jet collimation in a variety of objects from our Sun’s outflows to extragalatic jets. Furthermore, they provide…
Energy and time resolution for a LYSO matrix prototype of the Mu2e experiment
2016
We have measured the performances of a LYSO crystal matrix prototype tested with electron and photon beams in the energy range 60$-$450 MeV. This study has been carried out to determine the achievable energy and time resolutions for the calorimeter of the Mu2e experiment.
Comparison of tritium measurement techniques for a laser cleaned JET tile
2014
Abstract Over the last 7–8 years, two quantitative analyzing methods—accelerator mass spectrometry (AMS) and full combustion (FC) followed by scintillation detection have been applied for determining the tritium activity concentrations in JET divertor tiles. These methods have two main differences – the range of detection and the spatial resolution – and are thus complementary. However, these differences can also complicate the comparison of the two techniques for typical JET divertor samples. Therefore a cross comparison exercise for tritium measurements was performed between the two methods using specially produced identical standard samples. The cross comparison measurements were perform…
RADIOISOTOPE MASS SPECTROMETRY
2003
Mass spectrometric methods are very sensitive and enable in many cases a multielement determination of trace and ultratrace elements combined with a good isotopic analysis ( Bacon et al. , 2001 ). Therefore, these techniques are also applied for the detection of long-lived radionuclides ( Becker and Dietze, 2000 ) mainly in environmental samples ( Adriaens et al. , 1992 ; Bailey et al. , 1993 ; Bibler et al. , 1998 ; Eroglu et al. , 1998 ; Edmonds et al. , 1998 ; Becker and Dietze, 1999 ; Wendt et al. , 1999 ), nuclear materials ( Betti, 1997 ; Chartier et al. , 1999 ), glass and ceramics ( Rohr et al. , 1994 ; Fukuda and Sayama, 1997 ), and in high-purity substances ( Beer and Heumann, 199…