Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Zaima, Naoki; Nakashima, Shinichi; Kaneda, Koji; Kado, Kazumi
JAEA-Technology 2010-046, 31 Pages, 2011/02
JAEA-Technology-2010-046.pdf:2.84MBJAEA-Technology-2010-046(errata).pdf:0.05MB
The uranium mass assay systems for 200-litter wastes drums applied neutron and 
measurements by NDA method had been developed. The measurement systems and trial data are described in this preliminary report. The systems are composed of the 16 pieces of helium-3 proportional counters for neutron detection and a large sized NaI(Tl) scintillation detector for ray detection. The extensive testing trials using the calibrated uranium sources with different enrichment and some kinds of matrices in drums were performed. Through the one year testing the useful experiences of this system concerning neutron and ray measurements for uranium mass were obtained. Almost all instruments and software were so good performance as is designed. As the next step we are scheduled to try measurements for actual wastes that are stored in the Uranium Refining and Conversion Plant at Ningyo-toge, and put practical uses near future. Our research was accomplished with the support of LANL.
Yogo, Akifumi; Daido, Hiroyuki; Fukumi, Atsushi*; Li, Z.*; Ogura, Koichi; Sagisaka, Akito; Pirozhkov, A. S.; Nakamura, Shu*; Iwashita, Yoshihisa*; Shirai, Toshiyuki*; et al.
Physics of Plasmas, 14(4), p.043104_1 - 043104_6, 2007/04
Times Cited Count：63 Percentile：88.33(Physics, Fluids & Plasmas)Fast protons are observed by a newly-developed 
time-of-flight spectrometer, which provides 
proton-energy distributions immediately after the irradiation of a laser pulse having an intensity of 
W/cm
onto a 5-
m-thick copper foil. The maximum proton energy is found to increase when the intensity of a fs-prepulse arriving 9 ns before the main pulse increases from 10
to 10
W/cm. Interferometric measurement indicates that the preformed-plasma expansion at the front surface is smaller than 15 m, which corresponds to the spatial resolution of the diagnostics. This sharp gradient of the plasma makes a beneficial effect on increasing the absorption efficiency of the main-pulse energy, resulting in the increase in the proton energy. This is supported by the result that the X-ray intensity from the laser plasma clearly increases with the prepulse intensity.
Yokokawa, Mitsuo; Saito, Minoru*; Ishihara, Takashi*; Kaneda, Yukio*
Hai Pafomansu Komputingu To Keisan Kagaku Shimpojium (HPCS2002) Rombunshu, p.125 - 131, 2002/01
With the advent of supercomputers, large-scale direct numerical simulations(DNS) of the Navier-Stokes equations are possible to carry out. However, larger scale DNS is required to make turbulence clear and to make a parameterization of turbulence. The Earth Simulator is a distributed memory parallel supercomputer whose peak speed is 40 Tflop/s and it is very useful to make a very large-scale DNS. Simulation codes named 
have been developed for the Earth Simulator and their correctness have been validated by compareing the simulation results by with ones by a conventinal code. The sustatined performance of 3.72Gflop/s is obtained in the execution of the serial version with the problem size of 
on an arithmetic processor(AP) of the Earth Simulator. Speedup of about 7 is achieved in 8APs by the parallelized code. Sppedup is degraded by the execution of 8 processor nodes, however, efficiency of 25% against the peak performance is obtained for the problem size of 
.
Zaima, Naoki; Nakashima, Shinichi; Kaneda, Koji; Kado, Kazumi
no journal, ,
We developed uranium mass assay systems for 200-litter wastes drums applied neutron and measurements by NDA method. In this intermediate report we will describe measurement systems and trial data. The systems are composed of the 16 pieces of helium-3 proportional counters for neutron detection and a large sized NaI(Tl) scintillation detector for -ray detection. The extensive testing trials using the calibrated uranium sources with different enrichment and some kinds of matrices in drums were performed. Through the one year testing the useful experiences of this system concerning neutron and -ray measurements for uranium mass were obtained. Almost all instruments and software were so good performance as is designed. As the next step we are going to schedule to try measurements for actual wastes that are stored in the Uranium Refining and Conversion Plant at Ningyo-toge, and put practical uses near future. Our research was accomplished with the support of Los Alamos National Laboratory.
