Koichi Kino

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 .

Pulsed neutron imaging using 2-dimensional position sensitive detectors

2-dimensional position sensitive detectors are used for pulsed neutron imaging and at each pixel of the detector a time of flight spectrum is recorded. Therefore, a transmission spectrum through the object has wavelength dependent structure reflecting the neutron total cross section. For such measurements, the detectors are required to have ability to store neutron events as a function of the flight time as well as to have good spatial resolution. Furthermore, high counting rate is also required at the high intensity neutron sources like J-PARC neutron source in Japan. We have developed several types of detectors with different characteristics; two counting type detectors for high counting rate with coarse spatial resolution and one camera type detector for high spatial resolution. One of counting type detectors is a pixel type. The highest counting rate is about 28 MHz. Better spatial resolution is obtained by a GEM detector. Effective area is 10 × 10 cm2, pixel size is 0.8 mm. The maximum counting rate is 3.65 MHz. To get higher spatial resolution we are now developing the camera type detector system using a neutron image intensifier, which have image integration function as a function of time of flight. We have succeeded to obtain time dependent images in this camera system. By using these detectors we performed transmission measurements for obtaining the crystallographic information and elemental distribution images.

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.

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.

A dead-time correction method for multiple gamma-ray detection

To correct dead time in TOF experiments with multi-detector gamma-ray detection method, we have tested a dead-time correction method. In this dead-time correction method, random timing pulses generated by a random pulse generator are input to every pre-amplifier via test-signal inputs. Both the random timing pulses and the other pulses originated from gamma rays are measured with a data acquisition system (DAQ). At the same time, a number of the input random timing pulses are counted with another fast system. Because dead time affects similarly both the pulses from the random pulse generator and the measured gamma rays, we can calculate the dead time by comparing the number of the input random timing pulses counted by the fast system with an area count of the peak due to the random timing pulses measured with the DAQ.

Design of a Collimator System of a Neutron Beam Line for Neutron-Nucleus Reaction Measurements

Abstract A collimator system of a neutron beam line that is used for neutron-nucleus reaction measurements has been designed. Collimators in the middle region are optimized using a Monte Carlo simulation so that the neutron dose in the shielded area is as small as possible. A collimator closest to the experimental target is designed based on several origins of neutron backgrounds studied by the simulation. The simulation data finally obtained show a favorable background level and an expected neutron beam at the target position.

Accelerated Tests of Soft Errors in Network Systems Using a Compact Accelerator- Driven Neutron Source

The frequency of neutron-induced soft errors is increasing as devices become more integrated and miniaturized. Therefore, it has become more important recently to check reliability of a recovery system from the soft errors in network systems. For accelerated test, first we have examined possibility of the acceleration tests at a compact accelerator-driven neutron source, which is easy to adjust for soft-error tests and which also has low experimental costs. We selected the electron accelerator-driven neutron source at Hokkaido University as the compact accelerator-driven neutron source. We prepared a new target-reflector assembly composed of heavy metals to provide the fast neutrons, and conducted neutron-induced soft-error experiments on network equipments. As a result, we found that an accelerated rate of soft errors was about

Spatial resolution enhancement of neutron radiogram by cooperating with X-ray radiography

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Application of the J-PARC Neutron Beam to the Transmission Measurement for a Li Ion Battery during Charge and Discharge

times compared with that of the natural environment. We also investigated network equipment soft-error tolerance, fault detection and backup switching processes. Performing such testing before network equipment is actually deployed is critical for development of future network systems. Hence, the compact accelerator-based neutron source is a very useful tool.