Search results for "neutron source"
showing 10 items of 53 documents
The research reactor TRIGA Mainz – a strong and versatile neutron source for science and education
2019
Abstract The TRIGA Mark II-reactor at the Johannes Gutenberg University Mainz (JGU) is one of three research reactors in Germany. The TRIGA Mainz became first critical on August 3rd, 1965. It can be operated in the steady state mode with a maximum power of 100 kWth and in the pulse mode with a peak power of 250 MWth and a pulse length of 30 ms. The TRIGA Mainz is equipped with a central thimble, a rotary specimen rack, three pneumatic transfer systems, four beam tubes, and a graphite thermal column. The TRIGA Mainz is intensively used both for basic and applied research in nuclear chemistry and nuclear physics. Two sources for ultra-cold neutrons (UCN) are operational at two beam ports. At …
A search for point sources of EeV neutrons
2012
A thorough search of the sky exposed at the Pierre Auger Cosmic Ray Observatory reveals no statistically significant excess of events in any small solid angle that would be indicative of a flux of neutral particles from a discrete source. The search covers from −90◦ to +15◦ in declination using four different energy ranges above 1 EeV (1018 eV). The method used in this search is more sensitive to neutrons than to photons. The upper limit on a neutron flux is derived for a dense grid of directions for each of the four energy ranges. These results constrain scenarios for the production of ultrahigh energy cosmic rays in the Galaxy.
The alanine detector in BNCT dosimetry: Dose response in thermal and epithermal neutron fields
2014
Purpose: The response of alanine solid state dosimeters to ionizing radiation strongly depends on particle type and energy. Due to nuclear interactions, neutron fields usually also consist of secondary particles such as photons and protons of diverse energies. Various experiments have been carried out in three different neutron beams to explore the alanine dose response behavior and to validate model predictions. Additionally, application in medical neutron fields for boron neutron capture therapy is discussed. Methods: Alanine detectors have been irradiated in the thermal neutron field of the research reactor TRIGA Mainz, Germany, in five experimental conditions, generating different secon…
A neutron source for IGISOL-JYFLTRAP : Design and characterisation
2017
A white neutron source based on the Be(p, nx) reaction for fission studies at the IGISOL-JYFLTRAP facility has been designed and tested. 30MeV protons impinge on a 5mm thick water-cooled beryllium disc. The source was designed to produce at least 1012 fast neutrons/s on a secondary fission target, in order to reach competitive production rates of fission products far from the valley of stability. The Monte Carlo codes MCNPX and FLUKA were used in the design phase to simulate the neutron energy spectra. Two experiments to characterise the neutron field were performed: the first was carried out at The Svedberg Laboratory in Uppsala (SE), using an Extended-Range Bonner Sphere Spectrometer and …
On the nuclear response of the helium-cooled lithium lead test blanket module in ITER
2005
Abstract The helium-cooled lithium lead (HCLL) concept has been recently selected as one of the two European reference designs foreseen for the breeding blanket of a demonstration fusion reactor. In particular, within the framework of the research and development activities on this blanket line, an HCLL test blanket module (TBM) has to be designed and manufactured to be implemented in ITER. At the Department of Nuclear Engineering (DIN) of the University of Palermo, a research campaign has been carried out to investigate the nuclear response of HCLL-TBM inside ITER by a numerical approach based on the Monte Carlo method. A realistic 3D heterogeneous model of HCLL-TBM has been set-up and ins…
A study of the potential influence of frame coolant distribution on the radiation-induced damage of HCLL-TBM structural material
2008
Abstract Within the European Fusion Technology Programme, the Helium-Cooled Lithium Lead (HCLL) breeding blanket concept is one of the two EU lines to be developed for a Long Term fusion reactor, in particular with the aim of manufacturing a Test Blanket Module (TBM) to be implemented in ITER. The HCLL-TBM is foreseen to be located in an ITER equatorial port, being housed inside a steel-supporting frame, actively cooled by pressurized water. That supporting frame has been designed to house two different TBMs, providing two cavities separated by a dividing Plate 20 cm thick. As the nuclear response of HCLL-TBM might vary accordingly to the supporting frame configuration and composition, at t…
Study of the helium-cooled lithium lead test blanket module nuclear behaviour under irradiation in ITER
2009
Abstract The present paper deals with the detailed investigation of the helium-cooled lithium lead test blanket module (HCLL-TBM) nuclear behaviour under irradiation in ITER, carried out at the Department of Nuclear Engineering of the University of Palermo adopting a numerical approach based on the Monte Carlo method. A realistic 3D heterogeneous model of the HCLL-TBM was set-up and inserted into an ITER 3D semi-heterogeneous model that realistically simulates the reactor lay-out up to the cryostat. A Gaussian-shaped neutron source was adopted for the calculations. The main features of the HCLL-TBM nuclear response were assessed, paying a particular attention to the neutronic and photonic d…
Thermo-mechanical analysis of irradiation swelling and design optimization of the IFMIF target assembly with bayonet backplate
2017
Abstract The availability of a high flux neutron source for testing candidate materials under irradiation conditions, which will be typically encountered in future fusion power reactors (ITER, DEMO, FPR), is a fundamental step towards the development of fusion energy. To this purpose, the International Fusion Materials Irradiation Facility (IFMIF) represents the reference option to provide the fusion community with a DEMO-relevant neutron source capable of irradiating samples at a damage rate of up to 20 dpa/fpy (in steel) in a volume of 0.5 l. In the framework of the engineering design activities of IFMIF, ENEA is committed in the design of the lithium target assembly (TA) with removable (…
Neutronic and photonic analysis of the single box water-cooled lithium lead blanket for a DEMO reactor
1998
Abstract The water-cooled Pb–17Li demonstration plant (DEMO) breeding blanket line was selected in 1995 as one of the two EU lines to be further developed in the next decade. In this paper the results of a neutronic and photonic analysis of the `single box' concept is presented. A full three-dimensional model, including the whole assembly and many of the DEMO reactor components, has been developed, together with a three-dimensional neutron source. A tritium breeding ratio (TBR) value of 1.16, with no ports and a Li6 enrichment of 90%, has been obtained and a further analysis has been performed to determine Li6 enrichment that would still ensure tritium breeding self-sufficiency. Selected po…
Simulation of H- ion source extraction systems for the Spallation Neutron Source with Ion Beam Simulator.
2012
A three-dimensional ion optical code IBSimu, which is being developed at the University of Jyväskylä, features positive and negative ion plasma extraction models and self-consistent space charge calculation. The code has been utilized for modeling the existing extraction system of the H(-) ion source of the Spallation Neutron Source. Simulation results are in good agreement with experimental data. A high-current extraction system with downstream electron dumping at intermediate energy has been designed. According to the simulations it provides lower emittance compared to the baseline system at H(-) currents exceeding 40 mA. A magnetic low energy beam transport section consisting of two sole…