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J-PARC
J-PARC (Japan Proton Accelerator Research Complex) is a high intensity proton accelerator facility. It is a joint project between KEK and JAEA and is located at the Tokai campus of JAEA. J-PARC aims for the frontier in materials and life sciences, and nuclear and particle physics. J-PARC uses high intensity proton beams to create high intensity secondary beams of neutrons, hadrons, and neutrinos. Components J-PARC includes three main parts: the 400 MeV proton linear accelerator, the 3 GeV Rapid Cycling Synchrotron (RCS), and the 30 GeV Main Ring (MR) synchrotron. There are two main experimental areas: the Materials and Life Science Experimental Facility (MLF), where the proton beam from the RCS is used to create beams of either neutrons or muons for further study, and the Hadron Facility (HD), where the beam from the main ring is used to create heavy hadronic particles such as pions and kaons. The main ring beam is also used to create neutrino beams for analysis at the Kami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J-PARC
J-PARC (Japan Proton Accelerator Research Complex) is a high intensity proton accelerator facility. It is a joint project between KEK and JAEA and is located at the Tokai campus of JAEA. J-PARC aims for the frontier in materials and life sciences, and nuclear and particle physics. J-PARC uses high intensity proton beams to create high intensity secondary beams of neutrons, hadrons, and neutrinos. Components J-PARC includes three main parts: the 400 MeV proton linear accelerator, the 3 GeV Rapid Cycling Synchrotron (RCS), and the 30 GeV Main Ring (MR) synchrotron. There are two main experimental areas: the Materials and Life Science Experimental Facility (MLF), where the proton beam from the RCS is used to create beams of either neutrons or muons for further study, and the Hadron Facility (HD), where the beam from the main ring is used to create heavy hadronic particles such as pions and kaons. The main ring beam is also used to create neutrino beams for analysis at the Kami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Spin Echo
Neutron spin echo spectroscopy is an inelastic neutron scattering technique invented by Ferenc Mezei in the 1970s, and developed in collaboration with John Hayter. In recognition of his work and in other areas, Mezei was awarded the first Walter Haelg Prize in 1999. In magnetic resonance, a spin echo is the refocusing of spin magnetisation by a pulse of resonant electromagnetic radiation. The spin echo spectrometer possesses an extremely high energy resolution (roughly one part in 100,000). Additionally, it measures the density-density correlation (or intermediate scattering function) F(Q,t) as a function of momentum transfer Q and time. Other neutron scattering techniques measure the dynamic structure factor S(Q,ω), which can be converted to F(Q,t) by a Fourier transform, which may be difficult in practice. For weak inelastic features S(Q,ω) is better suited, however, for (slow) relaxations the natural representation is given by F(Q,t). Because of its extraordina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan Atomic Energy Agency
The is an Independent Administrative Institution formed on October 1, 2005 by a merger of two previous semi-governmental organizations. While it inherited the activities of both JNC and JAERI, it also inherited the nickname of JAERI, "Genken" 原研, an abbreviated word for "nuclear research". On April 10, 2007, JAEA officially joined the GNEP alliance. The other members in the alliance are Areva, Washington Group International and BWX. It is expected that the experience gained from the Rokkasho centrifuge enrichment plant will be a key contribution from JAEA. On April 1, 2016, JAEA transferred some of its laboratories to the National Institute of Radiological Sciences (NIRS), and the NIRS body was renamed to the National Institutes for Quantum and Radiological Science and Technology (QST) which includes existing laboratories of the NIRS. In 2018 JAEA estimated it would need about 1.9 trillion yen ($17.1 billion) to decommission 79 facilities over 70 years. Overview *Est ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Spallation Source
The European Spallation Source ERIC (ESS) is a multi-disciplinary research facility based on the world's most powerful pulsed neutron source. It is currently under construction in Lund, Sweden. The ESS Data Management and Software Centre (DMSC) will be located in Copenhagen, Denmark. The 13 European member countries act as partners in the construction and operation of ESS. ESS will start the scientific user programme in 2023, and the construction phase will be complete by 2025. ESS is the world's most powerful next-generation neutron source, and will enable scientists to see and understand basic atomic structures and forces at length and time scales unachievable at other neutron sources. The research infrastructure, owned by 13 European nations, is built close to the Max IV Laboratory. The colocation of powerful neutron and x-ray facilities is a productive strategy (e.g. the Institut Laue–Langevin with the European Synchrotron Radiation Facility; the ISIS Neutron and Muon Sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China Spallation Neutron Source
The China Spallation Neutron Source is an accelerator-based neutron source, operated by the Institute of High Energy Physics, under construction at Dongguan in Guangdong province - the first major scientific facility in south China. The project was approved by Chinese central government in 2005. Construction began 20 October 2011, with commissioning planned for 2016, and operation in 2018. The source contains a proton synchrotron fed by a linear accelerator; short (<500ns) pulses of 1.6 GeV protons are extracted from the synchrotron 25 times a second; these pulses strike a tungsten-metal target (cooled with heavy water) to produce energetic neutrons, which are reduced to scientifically-interesting energies by a variety of moderators. The intended budget for the project is 1.5 billion CNY;http://accelconf.web.cern.ch/AccelConf/a07/PAPERS/WEZMA02.PDF this limits the initial power ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton
A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ratio). Protons and neutrons, each with masses of approximately one atomic mass unit, are jointly referred to as "nucleons" (particles present in atomic nuclei). One or more protons are present in the nucleus of every atom. They provide the attractive electrostatic central force which binds the atomic electrons. The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number (represented by the symbol ''Z''). Since each element has a unique number of protons, each element has its own unique atomic number, which determines the number of atomic electrons and consequently the chemical characteristics of the element. The word ''proton'' is Greek for "first", and this name was given to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Small-angle Scattering
Biological small-angle scattering is a small-angle scattering method for structure analysis of biological materials. Small-angle scattering is used to study the structure of a variety of objects such as solutions of biological macromolecules, nanocomposites, alloys, and synthetic polymers. Small-angle X-ray scattering ( SAXS) and small-angle neutron scattering ( SANS) are the two complementary techniques known jointly as small-angle scattering (SAS). SAS is an analogous method to X-ray and neutron diffraction, wide angle X-ray scattering, as well as to static light scattering. In contrast to other X-ray and neutron scattering methods, SAS yields information on the sizes and shapes of both crystalline and non-crystalline particles. When used to study biological materials, which are very often in aqueous solution, the scattering pattern is orientation averaged. SAS patterns are collected at small angles of a few degrees. SAS is capable of delivering structural information in the re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Physics Facilities
In the physical sciences, a particle (or corpuscule in older texts) is a small localized object which can be described by several physical or chemical properties, such as volume, density, or mass. They vary greatly in size or quantity, from subatomic particles like the electron, to microscopic particles like atoms and molecules, to macroscopic particles like powders and other granular materials. Particles can also be used to create scientific models of even larger objects depending on their density, such as humans moving in a crowd or celestial bodies in motion. The term ''particle'' is rather general in meaning, and is refined as needed by various scientific fields. Anything that is composed of particles may be referred to as being particulate. However, the noun ''particulate'' is most frequently used to refer to pollutants in the Earth's atmosphere, which are a suspension of unconnected particles, rather than a connected particle aggregation. Conceptual properties The co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spin Echo
In magnetic resonance, a spin echo or Hahn echo is the refocusing of spin magnetisation by a pulse of resonant electromagnetic radiation. Modern nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) make use of this effect. The NMR signal observed following an initial excitation pulse decays with time due to both spin relaxation and any ''inhomogeneous'' effects which cause spins in the sample to precess at different rates. The first of these, relaxation, leads to an irreversible loss of magnetisation. But the inhomogeneous dephasing can be removed by applying a 180° ''inversion'' pulse that inverts the magnetisation vectors. Examples of inhomogeneous effects include a magnetic field gradient and a distribution of chemical shifts. If the inversion pulse is applied after a period ''t'' of dephasing, the inhomogeneous evolution will rephase to form an echo at time 2''t''. In simple cases, the intensity of the echo relative to the initial signal is given by ''e– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spallation Neutron Source
The Spallation Neutron Source (SNS) is an accelerator-based neutron source facility in the U.S. that provides the most intense pulsed neutron beams in the world for scientific research and industrial development.In 2007, SNS was entered into thGuinness Book of World Recordsas the most powerful pulsed spallation source. Each year, this facility hosts hundreds of researchers from universities, national laboratories, and industry, who conduct basic and applied research and technology development using neutrons. SNS is part of Oak Ridge National Laboratory, which is managed by UT-Battelle for the United States Department of Energy (DOE). SNS is a DOE Office of Science user facility, and it is open to scientists and researchers from all over the world. Neutron scattering research Neutron scattering allows scientists to count scattered neutrons, measure their energies and the angles at which they scatter, and map their final positions. This information can reveal the molecular and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reptation
A peculiarity of thermal motion of very long linear macromolecules in ''entangled'' polymer melts or concentrated polymer solutions is reptation. Derived from the word reptile, reptation suggests the movement of entangled polymer chains as being analogous to snakes slithering through one another. Pierre-Gilles de Gennes introduced (and named) the concept of reptation into polymer physics in 1971 to explain the dependence of the mobility of a macromolecule on its length. Reptation is used as a mechanism to explain viscous flow in an amorphous polymer. Sir Sam Edwards and Masao Doi later refined reptation theory. Similar phenomena also occur in proteins. Two closely related concepts are reptons and entanglement. A repton is a mobile point residing in the cells of a lattice, connected by bonds. Entanglement means the topological restriction of molecular motion by other chains. Theory and mechanism Reptation theory describes the effect of polymer chain entanglements on the relati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
