K. Furutaka

JENDL-4.0 : A New Library for Nuclear Science and Engineering

The fourth version of the Japanese Evaluated Nuclear Data Library has been produced in cooperation with the Japanese Nuclear Data Committee. In the new library, much emphasis is placed on the improvements of fission product and minor actinoid data. Two nuclear model codes were developed in order to evaluate the cross sections of fission products and minor actinoids. Coupled-channel optical model parameters, which can be applied to wide mass and energy regions, were obtained for nuclear model calculations. Thermal cross sections of actinoids were carefully examined by considering experimental data or by the systematics of neighboring nuclei. Most of the fission cross sections were derived from experimental data. A simultaneous evaluation was performed for the fission cross sections of important uranium and plutonium isotopes above 10 keV. New evaluations were performed for the thirty fissionproduct nuclides that had not been contained in the previous library JENDL-3.3. The data for light elements and structural materials were partly reevaluated. Moreover, covariances were estimated mainly for actinoids. The new library was released as JENDL-4.0, and the data can be retrieved from the Web site of the JAEA Nuclear Data Center.

Neutron-capture cross-sections of 244Cm and 246Cm measured with an array of large germanium detectors in the ANNRI at J-PARC/MLF

The neutron neutron-capture cross cross-sections of 244Cm and 246Cm were measured by the time-of-flight method in the energy range of 1–300 300 eV with an array of large germanium detectors in the Accurate Neutron-Nucleus Reaction measurement InstrumentANNRI at Material and Life Science Experimental Facility (MLF) of the Japan Proton Accelerator Research ComplexJ-PARC/MLF. The 244Cm resonances at around 7.7 and 16.8 8 eV and the 246Cm resonances at around 4.3 and 15.3 3 eV were observed in the capture reactions for the first time. The uncertainties of the obtained cross cross-sections are 5.8% at the top of the first resonance of 244Cm and 6.6% at that of 246Cm. The rResonance analyses were performed for low-energy ones using the code SAMMY. The prompt γ-ray spectra of 244Cm and 246Cm were also obtained. Eight and five new prompt γ-ray emissions were observed in the 244Cm(n, γ) and 246Cm(n, γ) reactions, respectively.

Cross-section measurement of 237Np (n, 𝛄) from 10 meV to 1 keV at Japan Proton Accelerator Research Complex

The cross-section of the 237Np reaction has been measured in the energy range from 10 meV to 1 keV using the ANNRI-NaI(Tl) spectrometer at the Japan Proton Accelerator Research Complex (J-PARC). The cross-section was obtained relative to that of the 10B reaction. The absolute value of the cross-section was deduced by normalizing the relative cross-section to the evaluated value of JENDL-4.0 at the first resonance. The thermal cross-section was obtained to be ( ) b. The Maxwellian-averaged cross-section for meV was derived as ( ) b by referring the cross-section below 10 meV from JENDL-4.0. These results lead to the Westcotts g-factor of .

JENDL Actinoid File 2008

JENDL Actinoid File 2008 (JENDL/AC-2008) was released in March 2008. It includes nuclear data for neutron-induced reactions for 79 nuclides from Ac (Z = 89) to Fm (Z = 100). The neutron energy range is 10−5 eV to 20 MeV. Almost alldata for 62 actinoids in JENDL-3.3 were revised. New evaluations were performed for 17 nuclides, which have half-lives longer than one day. A new comprehensive theoretical model code CCONE was widely used for the evaluation of cross sections and neutron emission spectra. Thermal cross sections for many nuclides were revised based on experimental data. Resonance parameters were readjusted to reproduce them. Simultaneous evaluations of fission cross sections were performed for six important nuclei. The least-squares fitting code GMA was used for the evaluation of fission cross sections for minor actinoids. In this paper, we present the evaluation methods and results of the JENDL/AC-2008.

Superdeformation in asymmetric N>Z nucleus 40Ar

Abstract A rotational band with five γ -ray transitions ranging from 2 + to 12 + states was identified in 40 Ar. This band is linked through γ transitions from the excited 2 + , 4 + and 6 + levels to the low-lying states; this determines the excitation energy and the spin–parity of the band. The deduced transition quadrupole moment of 1.45 − 0.31 + 0.49 ± 0.15 eb indicates that the band has a superdeformed shape. The nature of the band is revealed by cranked Hartree–Fock–Bogoliubov calculations and a multiparticle–multihole configuration is assigned to the band.

Improvement of a high speed and high density data acquisition system for multiple gamma-ray detection

To accelerate the data acquisition system (DAQ), which was reported in NSS 2004 [1], the authors improved the Main ADC Modules in the DAQ. The new Main ADC Module has 8 input channels. Each channel consists of analog circuits for pulse shaping, a high-speed ADC (14bit 125MSPS), and a high- power Digital Signal Processor (DSP: 8000MIPS). Shaped input signals are digitized with the ADC and analyzed by the DSP to calculate the energy data. For fast data transfer, the energy data from every four channels are bundled and stored into a large Dual Port Memory (DPM: 2MByte). The bundled data are read out to a PC through VME-BUS. By combining high-speed ADCs, high-power DSPs and large DPMs, high speed and high density DAQ was constructed.

Development of a 4π germanium spectrometer for nuclear data measurements at J-PARC

A 4π germanium spectrometer was developed for measurements of neutron capture cross sections of minor ac-tinides and long-lived-fission products. It was installed on the Beam Line No. 04 of the MLF in the J-PARC. We measured its full-energy peak efficiency and gamma-energy resolution at 1.3-MeV with a 60Co standard source (10kBq). As an example of a result of TOF measurements with the spectrometer, preliminary TOF and energy spectra of 108Pd are shown in this paper.

Application of multiple prompt gamma-ray analysis (MPGA) to geochemical and cosmochemical samples

A prompt gamma-ray analysis system using multiple detection method (MPGA system) was constructed at the neutron guide hall of the JRR-3M reactor of the Japan Atomic Energy Agency. We applied MPGA method to geochemical and cosmochemical samples to evaluate its analytical performance on signal to noise (S/N) ratio, sensitivity, and detection limit. The S/N ratio measured by MPGA system was larger than that by normal prompt gamma ray activation analysis (PGAA) at JRR-3M. For some elements, the S/N ratio was improved more than ten times. Several elements that are not detected by PGAA were detected by MPGA. At the present time, concentrations of major elements and trace elements with high neutron capture cross section in geochemical and cosmochemical samples were determined accurately by the MPGA system installed at JRR-3M. It is expected that it will determine a lot of trace elements after appropriate adjustments and modifications.

Measurement of Neutron Capture Cross Section Ratios of 244Cm Resonances Using NNRI

Measurement of Neutron Capture Cross Section Ratios of Cm Resonances Using NNRI Shinji GOKO a , Atsushi KIMURA a , Hideo HARADA a , Masumi OSHIMA a , Masayuki OHTA a , Kazuyoshi FURUTAKA a , Tadahiro KIN a , Fumito KITATANI a , Mitsuo KOIZUMI a , Shoji NAKAMURA a , Yosuke TOH a , Masayuki IGASHIRA b , Tatsuya KATABUCHI b , Motoharu MIZUMOTO c , Yoshiaki KIYANAGI c , Koichi KINO c , Michihiro FURUSAKA c , Fujio HIRAGA c , Takashi KAMIYAMA d , Jun-ichi HORI d , Toshiyuki FUJJI d , Satoshi FUKUTANI d & Koichi TAKAMIYA a a Nuclear Science and Engineering Directorate , Japan Atomic Energy Agency , Tokaimura, Naka-gun, Ibaraki , 319-1195 , Japan b Research Laboratory for Nuclear Reactors , Tokyo Institute of Technology , O-okayama, Meguro-ku, Tokyo , 152-8550 , Japan c Faculty of Engineering , Hokkaido University , Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido , 060-8628 , Japan d Research Reactor Institute , Kyoto University , Asashiro Nishi, Kumatori-cho, Sennangun, Osaka , 590-0494 , Japan Published online: 05 Jan 2012.

Feasibility study for the quantification of total protein content by multiple prompt gamma-ray analysis.

Protein is an important nutrient in foods. The classical nitrogen analysis method is the Kjeldahl technique, which is time-consuming and inconvenient. As a convenient method to quantify protein content in biological samples, the feasibility of application of multiple prompt gamma-ray analysis (MPGA) to the quantification was studied. Results for protein content are reported for several reference materials and prove the method to be reliable.