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Journal Articles

Data acquisition and display module for time-of-flight neutron measurement

To, Kentaro; Nakamura, Tatsuya; Sakasai, Kaoru; Yamagishi, Hideshi*

Proceedings of 2022 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room Temperature Semiconductor Detector Conference (2022 IEEE NSS MIC RTSD) (Internet), 3 Pages, 2022/11

A real-time data display and storage module was developed for time-of-flight neutron measurement. The module can display real-time experimental data from two-dimensional neutron detector in a two-dimensional image, one-dimensional projection images in X- and Y-axis, and time-of-flight spectra. The module has two modes of operation: standard mode, and simple-display mode. The simple-display mode only displays the experimental results on the monitor and can operate faster than that in the standard mode because the module uses the limited function. Therefore, the simple-display mode is also useful for measurement of high-counting rate neutrons. Operation test using test pulses were performed to confirm the operating speed of the module. The module in standard and simple-display mode could measure the continuous test pulses without counting losses with a frequency of 1.0 and 1.6 MHz, respectively.

Journal Articles

Evaluation of detector performances of new thin position-sensitive scintillation detectors for SENJU diffractometer

Nakamura, Tatsuya; To, Kentaro; Koizumi, Tomokatsu; Kiyanagi, Ryoji; Ohara, Takashi; Ebine, Masumi; Sakasai, Kaoru

Proceedings of 2022 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room Temperature Semiconductor Detector Conference (2022 IEEE NSS MIC RTSD) (Internet), 2 Pages, 2022/11

A new thin position-sensitive scintillation neutron detectors have been developed to replace present scintillation detectors in SENJU diffractometer at J-PARC MLF. The SENJU diffractometer originally composed of 37 position-sensitive detectors, where each detector has neutron sensitive area of 256 $$times$$ 256 mm with a pixel size of 4 $$times$$ 4 mm. To renew some original detectors the new detectors have been developed based on ZnS scintillator and wavelength-shifting fibers technology. The developed replacement detectors were designed with a thin thickness of 12 cm, which is 40% of the original detector. The new detectors have also improved detector performances to the original ones in terms of detection efficiency ($$sim$$60% for 2-A neutrons) and count uniformity (5-8%). The produced six detector modules have been implemented to the beamline after checking their detector performances in the lab.

Journal Articles

Two-dimensional scintillation neutron detectors for the extension of SENJU diffractometer

Nakamura, Tatsuya; To, Kentaro; Koizumi, Tomokatsu; Kiyanagi, Ryoji; Ohara, Takashi; Ebine, Masumi; Sakasai, Kaoru

Proceedings of 2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2020), Vol.1, p.483 - 484, 2021/09

Two-dimensional neutron detectors were developed for the extension of SENJU time-of-flight Laue single crystal neutron diffractometer in J-PARC MLF. The detectors are to be installed at the additional detector bank for the SENJU instrument. The detector module is made based on ZnS scintillator and wavelength-shifting fiber technology, where each detector module maintains a neutron-sensitive area of 256$$times$$256 mm with a pixel size of 4$$times$$4 mm. To meet the tight space limitation in the instrument, the detector was designed as compact as possible. The detector has a depth of 170 mm, which is about 40% smaller than that of the original SENJU detector. All four produced detectors exhibited similar detector performances: detection efficiency 50-60% for 2-${AA}$ neutron, $$^{60}$$Co gamma-ray sensitivity 1$$times$$10$$^{-5}$$, count uniformity 3-6%.

Journal Articles

A Two-dimensional scintillation neutron detector for TAKUMI diffractometer in J-PARC MLF

Nakamura, Tatsuya; Kawasaki, Takuro; To, Kentaro; Harjo, S.; Sakasai, Kaoru; Aizawa, Kazuya

JPS Conference Proceedings (Internet), 33, p.011097_1 - 011097_6, 2021/03

A large area, two-dimensional scintillation neutron detector was developed for Takumi diffractometer in the J-PARC MLF. The detector is made based on a scintillator/wavelength shifting fiber technology. The detector has a neutron-sensitive area of 32 $$times$$ 32 cm with a pixel size of 5 $$times$$ 5 mm, which is about 1.5-fold larger than the SENJU detector TAKUMI is one of the neutron diffractometers in the MLF dedicated to use for engineering material research. The developed detector array adds new capabilities to the instrument to measure two-dimensional data collection at the back-scattering angles with a better time-of-flight resolution.

Journal Articles

A Large area position-sensitive scintillation neutron detector for upgrading SENJU diffractometer

Nakamura, Tatsuya; To, Kentaro; Ebine, Masumi; Birumachi, Atsushi; Sakasai, Kaoru

Proceedings of 2019 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2019), Vol.1, p.735 - 736, 2020/08

 Times Cited Count:0 Percentile:0.08

A large area, position-sensitive scintillation neutron detector was developed for upgrading the SENJU, time-of-flight Laue single crystal neutron diffractometer, in J-PARC MLF. The detector has a neutron-sensitive area of 512 $$times$$ 512 mm with a pixel size of 4 $$times$$ 4 mm. The detector was developed for upgrading of the SENJU instrument. The large area detector is to be installed below the vacuum tank to enlarge a covering solid angle. A $$^{6}$$Li:ZnS (Ag) scintillator and wavelength-shifting fiber technologies are employed. Each fiber channel is read out individually with photon counting mode. The electronics boards are implemented at the backside of the detector, enabling the detector depth as short as 20 cm. The detector exhibited a detection efficiency of 45% for thermal neutron. No degradation in fiber position and in neutron sensitivity has been observed over one year after production. In this paper, detector design and detector performances are presented.

Journal Articles

Real-time data display and storage device for pulsed neutron scattering experiment

To, Kentaro; Nakamura, Tatsuya; Sakasai, Kaoru; Yamagishi, Hideshi*

Proceedings of 2019 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2019), Vol.1, p.447 - 449, 2020/08

 Times Cited Count:0 Percentile:0.08

A real-time data display and storage device was developed for pulsed neutron scattering experiments using the time-of-flight method. The device contains two sets of field programmable gate arrays and on-board microcomputers for data display and storage. The developed device can determine the time-of-flight and time-resolved neutron position data with a time range from 0 to 40 ms using a beam of pulsed neutrons at 25 Hz from an experimental facility. Operation tests were performed using test signals that simulate the neutron detector output signals. It was found that the device could separate double pulses with a time interval of 1 $$mu$$s; furthermore, it could measure the continuous pulses with a frequency of 1 MHz. Consequently, it was confirmed that the developed device demonstrated a counting rate capability of beyond 1 Mcps.

Journal Articles

A Submillimeter spatial resolution scintillation detector for time-of-flight neutron diffraction imaging

Nakamura, Tatsuya; Kawasaki, Takuro; To, Kentaro; Tsutsui, Noriaki; Ebine, Masumi; Birumachi, Atsushi; Sakasai, Kaoru

Proceedings of 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2018) (Internet), 3 Pages, 2019/10

A two-dimensional scintillation neutron detector with a submillimeter spatial resolution was developed for pulsed neutron diffraction imaging at the J-PARC MLF. The detector comprised the thin, single ZnS/$$^{6}$$LiF scintillator screen coupled with the crossed wavelength-shifting fiber array for light collection. For a high spatial resolution, the wavelength shifting fibers with diameter of 0.1 mm were used them for assembling the detector. The prototype detector that has a neutron-sensitive area of 24 $$times$$ 24 mm$$^{2}$$ exhibited a spatial resolution of 0.20$$pm$$0.06 mm and 0.16$$pm$$0.06 mm for x and y directions, respectively. The detector had a detection efficiency of 7$$%$$ for thermal neutrons with a $$^{60}$$Co $$gamma$$-ray sensitivity in the order of 10$$^{-6}$$. In this paper detailed detector design is presented together with experimental results using the pulsed neutron beam.

Journal Articles

Testing of time-of-flight neutron diffraction imaging using a high-resolution scintillator detector with wavelength-shifting fibers

Kawasaki, Takuro; Nakamura, Tatsuya; Gong, W.*; Oikawa, Kenichi

Physica B; Condensed Matter, 551, p.460 - 463, 2018/12

 Times Cited Count:1 Percentile:10.5(Physics, Condensed Matter)

Journal Articles

Diagnosis of neutron sensitivity within a scintillator/wavelength-shifting fiber coil element by using a collimated pulsed neutron beam

Nakamura, Tatsuya; To, Kentaro; Tsutsui, Noriaki; Ebine, Masumi; Birumachi, Atsushi; Sakasai, Kaoru

Proceedings of 2016 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2016), Vol.2, p.1506 - 1508, 2018/01

Position-dependent neutron sensitivity within an element of the scintillator / wavelength-shifting fiber coil (SFC) was evaluated by using a collimated pulsed neutron beam at the J-PARC/MLF. The collimated beam that has a size of 1 $$times$$ 1 mm$$^{2}$$ was scanned over the SFC element. The neutron counts were recorded and plotted in each incident position. The scanning results showed less neutron sensitivity at the juncture of the rolled scintillator, suggesting less light collection efficiency or a lack of scintillator materials due to imperfect manufacturing process.

Journal Articles

Development of a bump cathode element for two-dimensional neutron detection

To, Kentaro; Nakamura, Tatsuya; Sakasai, Kaoru; Yamagishi, Hideshi*

Journal of Instrumentation (Internet), 12(12), p.C12011_1 - C12011_8, 2017/12

 Times Cited Count:0 Percentile:0.01(Instruments & Instrumentation)

A neutron-detection element using circular cathode bumps was developed for two-dimensional neutron measurement, and an irradiation experiment was performed using a $$^{252}$$Cf neutron source. The element has triangularly arranged small-sized circular cathode bumps, and the bumps are linked together in the x- and y-directions for the detection of incident neutrons. The element was arranged in the pressure vessel with a fill gas of composition He/(15%)CF$$_{4}$$ at 0.7 MPa. The detector system using bump cathode element exhibited a two-dimensional uniformity with a response of 10.1%. The average intrinsic spatial resolution was 1.89 mm full width at half maximum in the sensitive region, calculated by taking into account the track lengths of the secondary particles.

Journal Articles

Development of a position-sensitive scintillation neutron detector for a new protein single-crystal diffractometer at J-PARC MLF

Nakamura, Tatsuya; To, Kentaro; Tsutsui, Noriaki; Ebine, Masumi; Birumachi, Atsushi; Sakasai, Kaoru

Journal of Instrumentation (Internet), 12(12), p.C12025_1 - C12025_9, 2017/12

 Times Cited Count:1 Percentile:5.86(Instruments & Instrumentation)

A high-spatial-resolution, large-area position-sensitive scintillation-based neutron detector module has been developed for a new time-of-flight Laue single-crystal diffractometer to be constructed at J-PARC MLF. A first prototype detector implementing commercial $$^{6}$$Li:ZnS screens was produced based on a scintillator/wavelength-shifting fibre technology. The detector exhibited a spatial resolution of 2.5 mm with a neutron-sensitive area of 320 $$times$$ 320 mm$$^{2}$$. We report on an initial evaluation of the detector performance, including its spatial resolution, detection efficiency and long-term background measurement, and also provide a brief description of a new neutron instrument.

Journal Articles

Materials and Life Science Experimental Facility at the Japan Proton Accelerator Research Complex, 3; Neutron devices and computational and sample environments

Sakasai, Kaoru; Sato, Setsuo*; Seya, Tomohiro*; Nakamura, Tatsuya; To, Kentaro; Yamagishi, Hideshi*; Soyama, Kazuhiko; Yamazaki, Dai; Maruyama, Ryuji; Oku, Takayuki; et al.

Quantum Beam Science (Internet), 1(2), p.10_1 - 10_35, 2017/09

Neutron devices such as neutron detectors, optical devices including supermirror devices and $$^{3}$$He neutron spin filters, and choppers are successfully developed and installed at the Materials Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC), Tokai, Japan. Four software components of MLF computational environment, instrument control, data acquisition, data analysis, and a database, have been developed and equipped at MLF. MLF also provides a wide variety of sample environment options including high and low temperatures, high magnetic fields, and high pressures. This paper describes the current status of neutron devices, computational and sample environments at MLF.

Journal Articles

Development of scintillation neutron detector using wavelength-shifting fiber technology

Nakamura, Tatsuya; To, Kentaro; Sakasai, Kaoru

Hamon, 27(1), p.4 - 7, 2017/01

Development of scintillation neutron detectors using wavelength-shifting fiber (WLSF) technology at J-PARC MLF is briefly reviewed. The neutron-detecting head of this type detector comprises neutron-sensitive scintillator screens and WLSFs for light read out. The light collection using WLSFs enables us to design a detector with great flexibility. Detector specifications such as pixel size, spatial resolution, and neutron-sensitive area can be optimized to requirements in specific applications. We have intensively developed these detectors since 2005. A large number of detector modules have been produced and delivered to the neutron scattering instruments in the MLF. In this paper the design of SENJU detector is presented in detail together with recent development effort for detector technology alternative to helium-3 gas detectors.

Journal Articles

A 64$$times$$64 cm$$^{2}$$ area position-sensitive scintillation neutron detector as an alternative to helium-3 gas based detector

Nakamura, Tatsuya; To, Kentaro; Honda, Katsunori; Ebine, Masumi; Birumachi, Atsushi; Sakasai, Kaoru

Proceedings of 2015 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2015), Vol.1, p.680 - 683, 2016/11

A two-dimensional scintillation neutron detector that has neutron-sensitive area of 64 $$times$$ 64 cm$$^{2}$$ was developed for neutron scattering instruments by using wavelength shifting fibers technology. We designed the detector to have a pixel size of 20 $$times$$ 20 mm$$^{2}$$. In order to compensate light attenuation occurred travelling along the wavelength-shifting fiber the scintillation light was read out from both sides of the fiber. The prototype detector exhibited a detection efficiency of 40% for 1.8${AA}$ neutrons, which was similar to previously developed detector with a smaller size of 32 $$times$$ 32 cm$$^{2}$$. The detailed detector design and experimental results measured by using the pulsed neutrons at the J-PARC/MLF are presented.

Journal Articles

SrBPO$$_{5}$$:Eu$$^{2+}$$ storage phosphors for wide-range neutron detection

Sakasai, Kaoru; To, Kentaro; Nakamura, Tatsuya; Ochiai, Kentaro; Konno, Chikara

Proceedings of 2014 IEEE Nuclear Science Symposium and Medical Imaging Conference; 21st International Symposium on Room-Temperature Semiconductor X-ray and $$gamma$$-ray detectors (NSS/MIC 2014), Vol.3 , p.1834 - 1839, 2016/05

no abstracts in English

Journal Articles

Development of position-sensitive scintillation neutron detectors at J-PARC/MLF

Nakamura, Tatsuya; To, Kentaro; Sakasai, Kaoru; Honda, Katsunori; Soyama, Kazuhiko; Katagiri, Masaki*

JAEA-Conf 2015-002, p.391 - 398, 2016/02

Development of position-sensitive scintillator detectors at the J-PARC/MLF is briefly reviewed. The detector development for the neutron scattering instruments in the J-PARC/MLF initiated back in 2001. After the basic experiments and design study we have produced first beam line detectors in 2008 both with the one and two-dimensional position-sensitivity. With an extension of the fiber detector technology the detector that has an active area of 256 $$times$$ 256 mm$$^{2}$$ with a 4-mm spatial resolution was designed and made for the single crystal diffractometer, SENJU, in 2011. In the presentation recent development work including the alternative detectors to $$^{3}$$He gas is also introduced as well as the new detector development for the nextiBIX instrument.

Journal Articles

A Ceramic-insulated ball-anode element for two-dimensional neutron detector

To, Kentaro; Nakamura, Tatsuya; Sakasai, Kaoru; Yamagishi, Hideshi*

Proceedings of 2016 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2016) (Internet), 2 Pages, 2016/00

A ceramic-insulated ball-anode (CiB) element that consists of a ceramic insulator, cathode lines, ball-shaped anodes, and anode lines was developed, and an irradiation experiment was performed using a Cf-252 neutron source. An electric field simulation of CiB element was conducted and strong electric fields of more than 10$$^{7}$$ V/m was obtained by the calculation using the finite element method. The neutron-induced signals of all pixels were observed using 8 $$times$$ 8 pixel small-sized test element under Cf-252 neutron irradiation.

Journal Articles

Numerical evaluation of the light transport properties of alternative He-3 neutron detectors using ceramic scintillators

Ozu, Akira; Takase, Misao*; Haruyama, Mitsuo; Kurata, Noritaka*; Kobayashi, Nozomi*; Kureta, Masatoshi; Nakamura, Tatsuya; To, Kentaro; Sakasai, Kaoru; Suzuki, Hiroyuki; et al.

Nuclear Instruments and Methods in Physics Research A, 798, p.62 - 69, 2015/10

 Times Cited Count:2 Percentile:17.75(Instruments & Instrumentation)

The light transport properties of scintillator light inside alternative He-3 neutron detector modules using scintillator sheets have been investigated by a ray-tracing simulation code. The detector module consists of a light-reflecting tube, a thin rectangular ceramic scintillator sheet laminated on a glass plate, and two photo-multiplier tubes (PMTs) mounted at both ends of the detector tube. The light induced on the surface of the scintillator sheet via nuclear interaction between the scintillator and neutrons are detected by the two PMTs. The light output of various detector modules in which the scintillator sheets are installed with several different arrangements were examined and evaluated in comparison with experimental results. The results derived from the simulation reveal that the light transport property is strongly dependent on the arrangement of the scintillator sheet inside the tube and the shape of the tube.

Journal Articles

Development of a ceramic-insulated ball-anode element for neutron detection

To, Kentaro; Nakamura, Tatsuya; Sakasai, Kaoru; Soyama, Kazuhiko; Yamagishi, Hideshi*

Nuclear Instruments and Methods in Physics Research A, 784, p.194 - 197, 2015/06

 Times Cited Count:1 Percentile:9.79(Instruments & Instrumentation)

A novel ceramics insulated detector element was developed for neutron measurement. The developed detector element consists of a ceramics insulator, cathode lines on the insulator, and ball-shaped anodes. The incident neutrons are usually scattered by the detector element itself because it acts as scatterer. To estimate the effects of scattering, we calculated the amount of neutrons scattered by the developed element. By the calculation results by a Monte Carlo simulation using PHITS, it is found that the developed element is effective to reduce the scattered neutrons. The number of scattered neutrons of the developed element is 40% smaller than that of polymer insulated element, which is widely used in micro-pattern element. Finally, neutron-induced signals were clearly observed using the developed detector element.

Journal Articles

A Two-dimensional scintillation-based neutron detector with wavelength-shifting fibers and incorporating an interpolation method

Nakamura, Tatsuya; To, Kentaro; Kawasaki, Takuro; Ebine, Masumi; Birumachi, Atsushi; Sakasai, Kaoru; Soyama, Kazuhiko

Nuclear Instruments and Methods in Physics Research A, 784, p.202 - 207, 2015/06

 Times Cited Count:2 Percentile:17.75(Instruments & Instrumentation)

A two-dimensional scintillation neutron detector incorporating an interpolation method readout by wavelength-shifting (WLS) fiber was developed to make an effective pixel size smaller than the physical pitch of the WLS fibre array. The detector that was made with the crossed arranged WLS fiber arrays where the fibers were placed in a regular pitch of 2.5 mm in $$x$$ and $$y$$ directions. The dedicated signal processing algorithms that calculated an incident position of neutron with a base length of the same, half and quarter of the physical WLS fiber pitch were developed for the detector operated in a photon-counting method. The paper demonstrated the feasibility of the developed interpolation method using a collimated neutron beam.

251 (Records 1-20 displayed on this page)