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In the upcoming JAXA/ERG satellite mission, Wave Particle Interaction Analyzer (WPIA) will be installed as an onboard software function. We study the statistical significance of the WPIA for measurement of the energy transfer process between energetic electrons and whistler-mode chorus emissions in the Earth's inner magnetosphere. The WPIA measures a relative phase angle between the wave vector E and velocity vector v of each electron and computes their inner product W, where W is the time variation of the kinetic energy of energetic electrons interacting with plasma waves. We evaluate the feasibility by applying the WPIA analysis to the simulation results of whistler-mode chorus generation. We compute W using both a wave electric field vector observed at a fixed point in the simulation system and a velocity vector of each energetic electron passing through this point. By summing up Wi of an individual particle i to give Wint, we obtain significant values of Wint as expected from the evolution of chorus emissions in the simulation result.We can discuss the efficiency of the energy exchange through wave-particle interactions by selecting the range of the kinetic energy and pitch angle of the electrons used in the computation of Wint. The statistical significance of the obtained Wint is evaluated by calculating the standard deviation σW of Wint. In the results of the analysis, positive or negative Wint is obtained at the different regions of velocity phase space, while at the specific regions the obtained Wint values are significantly greater than σW, indicating efficient wave-particle interactions. The present study demonstrates the feasibility of using the WPIA, which will be on board the upcoming ERG satellite, for direct measurement of wave-particle interactions. [ABSTRACT FROM AUTHOR]

In order to handle high intensity primary proton beam provided by Japan Proton Accelerator Research Complex (J-PARC), radiation-resistant beam lines have been constructed at Hadron Experimental Hall of J-PARC. The key technology of the radiation-resistant beam line is the radiation-resistant magnets. However all the peripheral devices of the magnets were designed and assembled as radiation-resistant ones since peripherals as well as magnets should be operated in very high radiation environment. In addition a safe operation and maintenance scheme of high intensity beam lines has been established based on the Chimney technology of radiation-resistant magnets including their peripherals. Then the beam lines in the Hadron Experimental Hall have been constructed with “radiation-resistant magnet system”. [ABSTRACT FROM PUBLISHER]

The construction of the facility of the long baseline neutrino oscillation experiment using the J-PARC's 50 GeV–0.75 MW proton beam refid="ref1"/ was completed at the end of 2008. The number of radiation-resistant magnets we have prepared for the neutrino beamline of J-PARC were 15 with Polyimide resin Insulation(PI) against up to 10^8 Gy, and 4 magnets with completely Mineral Insulation Cable (MIC) for higher radiation dose up to 10^11 Gy, and 2 magnets with Epoxy resin Insulation. All magnets were equipped with remote handling system, i.e. automated magnet lifts, quick alignment guides, water connectors, electric power connectors and interlock-signal connectors. [ABSTRACT FROM PUBLISHER]

We have developed the most upstream dipole magnet K1.1D1 for a new secondary beam line at the hadron experimental hall in J-PARC. It is placed downstream of a production target and is close to the K1.8D1 magnet. Indirectly cooled coils using mineral insulation cables have been adopted for high radiation resistance. The coils have a slanting saddle shape in order to minimize the interference of the magnetic field between the two magnets. It has been operated during the beam time in the autumn of 2010 without any problems. [ABSTRACT FROM PUBLISHER]

Abstract: The dimensional stability, elastic modulus, and flexural strength of a high quality, three-dimensional balanced weave carbon fiber composite has been evaluated over a range of neutron fluence to ∼32dpa at ∼800°C. Results indicate that while the composite exhibits continuous strengthening over this dose range, this occurs with measurable loss of mass, increased volume, and for the highest dose studied, a large reduction in elastic modulus. While the balanced-weave composite was orthogonally isotropic, a significant anisotropic dimensional change occurred under irradiation. Dimensional change was dominated by fiber dimensional change and the overall shrinkage or swelling in a direction was determined by the extent to which intrinsic fiber shrinkage was capable of restraining swelling of matrix and fiber bundles. [Copyright &y& Elsevier]

There has been a great concern about the origin of the parallel electric field in the frame of fluid equations in the auroral acceleration region. This paper proposes a new method to simulate magnetohydrodynamic (MHD) equations that include the electron convection term and shows its efficiency with simulation results in one dimension. We apply a third-order semi-discrete central scheme to investigate the characteristics of the electron convection term including its nonlinearity. At a steady state discontinuity, the sum of the ion and electron convection terms balances with the ion pressure gradient. We find that the electron convection term works like the gradient of the negative pressure and reduces the ion sound speed or amplifies the sound mode when parallel current flows. The electron convection term enables us to describe a situation in which a parallel electric field and parallel electron acceleration coexist, which is impossible for ideal or resistive MHD. [ABSTRACT FROM AUTHOR]

Observations are presented of monochromatic whistler waves near the Moon detected by the Lunar Magnetometer (LMAG) on board Kaguya. The waves were observed as narrowband magnetic fluctuations with frequencies close to 1 Hz, and were mostly left-hand polarized in the spacecraft frame. We performed a statistical analysis of the waves to identify the distributions of their intensity and occurrence. The results indicate that the waves were generated by the solar wind interaction with lunar crustal magnetic anomalies. The conditions for observation of the waves strongly depend on the solar zenith angle (SZA), and a high occurrence rate is recognized in the region of SZA between 40° to 90° with remarkable north-south and dawndusk asymmetries. We suggest that ion beams reflected by the lunar magnetic anomalies are a possible source of the waves [ABSTRACT FROM AUTHOR]

J-PARC Hadron Experimental Facility is designed to carry out a variety of particle and nuclear physics experiments with intense secondary particles generated by 750 kW proton beams. The first construction stage including the experimental hall, the primary beam line, and one secondary beam line (K1.8BR) has been completed at the end of December 2008. In order to handle the high intensity primary beam safely, we have developed many special devices working under severe radiation environment. The present article reports the current status of the Hadron Experimental Facility in detail. [ABSTRACT FROM AUTHOR]

As part of the U.S. ITER test blanket module development effort, several flow channel insert (FCI) concepts using a variety of porous SiC and SiC/SiC composites are being developed. Using porous SiC, prototypes of FCI segments as large as 0.12\ \m \times 0.75\ \m \times 0.015\ \m were fabricated and heat tested with a maximum \Delta T of \sim150\ ^\circ\C across the FCI walls. In this paper, we report on two heat tests of the FCI prototypes. The first test used radiative heating of the inside of the FCI along with convective cooling of the outside of the FCI, which resulted in a temperature drop of about \sim147\ ^\circ\C across the FCI wall. The second test involved partial submersion of the FCI structure in liquid PbLi, resulting in an inner wall surface temperature of about 600 ^\circ\C and an outer wall temperature of about 450 ^\circ\C\ (\Delta T \sim 150\ ^\circ \C). Detailed thermomechanical analyses of the tests were conducted, and results of the simulations are discussed in the context of actual FCI operating conditions. [ABSTRACT FROM PUBLISHER]

In order to clarify the role of the mode conversion process in the generation mechanism of LO-mode waves in the equatorial region of the plasmasphere, we have investigated the linear mode conversion process among upper-hybrid-resonance (UHR)-mode, Z-mode and LOmode waves by a numerical simulation solving Maxwell's equations and the equation of motion of a cold electron fluid. The wave coupling process occurring in the cold magnetized plasma are examined in detail. In order to give a realistic initial plasma condition in the numerical experiments, we use initial parameters inferred from observation data obtained around the generation region of LO-mode waves obtained by the Akebono satellite. A density gradient is estimated from the observed UHR frequency, and wave normal angles are estimated from the dispersion relation of cold plasma by comparing observed wave electric fields. Then, we perform numerical experiments of mode conversion processes using the density gradient of background plasma and the wave normal angle of incident upper hybrid mode waves determined from the observation results. We found that the characteristics of reproduced LO-mode waves in each simulation run are consistent with observations. [ABSTRACT FROM AUTHOR]

More than 50 radiation-resistant electromagnets were constructed for the primary proton and the secondary particle beam lines of the Hadron Experimental Hall of Japan Proton Accelerator Research Complex (J-PARC). The main radiation- resistant technologies we employed were the Polyimide-resin Insulation conductor for magnets at the relatively low radiation exposure and the Mineral Insulation Cable for magnets at the seriously high radiation environment. The remote handling and maintenance scheme of radiation-resistant magnets for seriously high radiation environment was developed also based on the Chimney magnet technology and applied to magnets near the production target in the Hadron Hall. On January 27th 2009, the first proton beam was successfully introduced to the Hadron Hall from the main accelerator of J-PARC, i.e. 50 GeV Proton Synchrotron. On February 10th, the secondary particles were extracted to the experimental area of the Hadron Hall through the secondary particle beam line. No serious problem happened on magnets of both primary proton and the secondary particle beam lines until the end of the beam operation scheduled on February 26th. [ABSTRACT FROM AUTHOR]

The target station in the hadron experimental facility at J-PARC consists of a production target and a huge vacuum chamber in which several secondary-beam-line magnets can work. This vacuum chamber system aims to remove the vacuum beam pipe from the magnet gap, because the cooling of the beam pipe is the most serious problem in the high intensity beam facility. We have developed indirectly cooled radiation-resistant magnets for the hadron target station. Their coils are made of solid-conductor type mineral-insulation cables and stainless-steel water pipes. They have the great advantages that electric circuits can be completely independent of water pass. The mechanical strength and the insulation performance of the coil are significantly improved also because the insulation water pipes can be avoided from the water pass. A C-type sector dipole and a figure-8-type quadrupole magnet have been fabricated by using indirectly cooled radiation-resistant magnet technology, and installed in the vacuum chamber. We have succeeded to operate them in vacuum stably with the current of DC 1000 A by improving the end structure of the MIC coils and increasing their emissivity. These magnets have been used for the real beam operation without any serious problems. [ABSTRACT FROM AUTHOR]