Search results for "nuclear physics"
showing 10 items of 5307 documents
Major results from the first plasma campaign of the Wendelstein 7-X stellarator
2017
After completing the main construction phase of Wendelstein 7-X (W7-X) and successfully commissioning the device, first plasma operation started at the end of 2015. Integral commissioning of plasma start-up and operation using electron cyclotron resonance heating (ECRH) and an extensive set of plasma diagnostics have been completed, allowing initial physics studies during the first operational campaign. Both in helium and hydrogen, plasma breakdown was easily achieved. Gaining experience with plasma vessel conditioning, discharge lengths could be extended gradually. Eventually, discharges lasted up to 6 s, reaching an injected energy of 4 MJ, which is twice the limit originally agreed for t…
Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13 TeV Proton-Proton Collisions at the LHC
2017
MoEDAL is designed to identify new physics in the form of long-lived highly-ionising particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a first search for magnetic monopole production in 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8 TeV data during LHC run-1. A total of 222 kg of MoEDAL trapping detector samples was exposed in the forward region and analysed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges excee…
Total and linearly polarized synchrotron emission from overpressured magnetized relativistic jets
2018
We present relativistic magnetohydrodynamic (RMHD) simulations of stationary overpressured magnetized relativistic jets, which are characterized by their dominant type of energy: internal, kinetic, or magnetic. Each model is threaded by a helical magnetic field with a pitch angle of 45° and features a series of recollimation shocks produced by the initial pressure mismatch, whose strength and number varies as a function of the dominant type of energy. We perform a study of the polarization signatures from these models by integrating the radiative transfer equations for synchrotron radiation using as inputs the RMHD solutions. These simulations show a top-down emission asymmetry produced by …
Severe Psychological Distress of Evacuees in Evacuation Zone Caused by the Fukushima Daiichi Nuclear Power Plant Accident: The Fukushima Health Manag…
2015
Background Following the Great East Japan Earthquake on March 11, 2011, the nuclear disaster at the Fukushima Daiichi Nuclear Power Plant has continued to affect the mental health status of residents in the evacuation zone. To examine the mental health status of evacuee after the nuclear accident, we conducted the Mental Health and Lifestyle Survey as part of the ongoing Fukushima Health Management Survey. Methods We measured mental health status using the Kessler 6-item psychological distress scale (K6) in a total of 73,569 (response rate: 40.7%) evacuees aged 15 and over who lived in the evacuation zone in Fukushima Prefecture. We then dichotomized responders using a 12/13 cutoff on the K…
Regional deprivation and non-cancer related computed tomography use in pediatric patients in Germany: Cross-sectional analysis of cohort data.
2016
BACKGROUND: Conflicting findings were observed in recent studies assessing the association between patients' area-level socio-economic status and the received number of computed tomography (CT) examinations in children. The aim was to investigate the association between area-level socio-economic status and variation in CT examination practice for pediatric patients in Germany. METHODS: Data from Radiology Information Systems for children aged 0 to < 15 years without cancer who had at least one CT examination between 2001 and 2010 were extracted in 20 hospitals across Germany. The small-area German Index of Multiple Deprivation (GIMD) was used to assess regional deprivation. The GIMD …
Many body modes of antiproton annihilation tested with antiproton production
1992
We study the inclusive (y,¯ p) and (p,p) reactions in nuclei and check the sensitivity to the¯p annihilation mechanisms. We find that including the many body annihilation mechanisms in nuclei reduces appreciably the cross section of these reactions with respect to the evaluation considering only the one body mechanism of¯p annihilation. This shows that the¯p production reactions are more sensitive to¯p annihilation than the direct¯p annihilation reactions and makes the production experiments very useful tools to investigate the complex mechanisms of¯p annihilation in nuclei.
High-accuracy mass measurements on neutron deficient neon isotopes
2005
International audience; The atomic masses of the short-lived nuclides 17Ne and 19Ne have been measured with the triple-trap mass spectrometer ISOLTRAP at ISOLDE/CERN. The obtained mass excess for both nuclides deviates significantly from the literature value, in the case of 17Ne about 40 keV. The mass value of 17Ne can be applied for a test of the isobaric multiplet mass equation with respect to an isospin T = 3/2 quartet. In addition, both masses can contribute to the data analysis of collinear laser-spectroscopy experiments where mean-square nuclear-charge radii are determined.
Improved Skyrme forces for Hartree-Fock seniority calculations
1992
Abstract The relationship between Skyrme parameters and physical quantities in nuclear matter is discussed in detail and bounds for some parameters are derived. Improved density-dependent two-body Skyrme forces are obtained by a least-squares fit of all the parameters simultaneously to a large set of data, including nuclear matter, mass formula and Landau parameters, and data of finite nuclei. Special attention is paid to the pairing properties of the interaction. These forces are used to perform self-consistent calculations in spherical closed-shell nuclei and Ca open-shell isotopes, within the Hartree-Fock seniority method. Good agreement with experimental data is obtained.
Mass Measurements with the CSS2 and CIME cyclotrons at GANIL
2005
Commune avec ACEN; This paper presents two original direct mass-measurement techniques developed at GANIL using the CSS2 and CIME cyclotrons as high-resolution mass spectrometers. The mass measurement with the CSS2 cyclotron is based on a time-of-flight method along the spiral trajectory of the ions inside the cyclotron. The atomic mass excesses of 68Se and 80Y recently measured with this technique are -53.958(246) MeV and -60.971(180) MeV, respectively. The new mass-measurement technique with the CIME cyclotron is based on the sweep of the acceleration radio-frequency of the cyclotron. Tests with stable beams have been performed in order to study the accuracy of this new mass-measurement m…
Multiplicity dependence of light (anti-)nuclei production in p–Pb collisions at sNN=5.02 TeV
2020
The measurement of the deuteron and anti- deuteron production in the rapidity range −1 < y < 0 as a function of transverse momentum and event multiplicity in p–Pb collisions at √sNN= 5.02 TeV is presented. (Anti-)deuterons are identified via their specific energy loss dE/dxand via their time-of-flight. Their production in p–Pb collisions is compared to pp and Pb–Pb collisions and is discussed within the context of thermal and coalescence models. The ratio of integrated yields of deuterons to protons (d/p) shows a significant increase as a function of the charged-particle multiplicity of the event starting from values similar to those observed in pp collisions at low multiplicities and appro…