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Journal Articles

Charge-collection efficiency and long-term stability of single-crystal CVD diamond detector under different carrier-drift conditions

Sato, Yuki; Murakami, Hiroyuki*; Shimaoka, Takehiro*; Tsubota, Masakatsu*; Kaneko, Junichi*

Japanese Journal of Applied Physics, 55(4), p.046401_1 - 046401_5, 2016/04

 Times Cited Count:4 Percentile:19.99(Physics, Applied)

We investigated the performance of a charged particle detector fabricated using single-crystal diamond grown by chemical vapor deposition. The detector was able to identify four different $$^{241}$$Am $$alpha$$-particle energies (5.389, 5.443, 5.486, and 5.545 MeV) because of its superior intrinsic energy resolution of $$sim$$0.4% (full width at half maximum). The charge collection efficiency inside the diamond crystal was $$sim$$98% for both electrons and holes. The diamond detector also exhibited no significant degradation in terms of pulse height spectra and energy resolution during operation for more than 100 h in the case of mainly electron drift inside the diamond crystal. In contrast, the shapes of the pulse height spectra measured under hole drift condition deteriorated due to the polarization phenomenon.

JAEA Reports

Performance tests of radiation detectors for inspection of $$^{99}$$Mo/$$^{99m}$$Tc solution, 1

Suzuki, Yumi*; Nakano, Hiroko; Suzuki, Yoshitaka; Ishida, Takuya; Shibata, Akira; Kato, Yoshiaki; Kawamata, Kazuo; Tsuchiya, Kunihiko

JAEA-Technology 2015-031, 58 Pages, 2015/11

JAEA-Technology-2015-031.pdf:14.57MB

Technetium-99m ($$^{99m}$$Tc) is one of the most commonly used radioisotopes in the field of nuclear medicine. In the Japan Atomic Energy Agency (JAEA), the research and development (R&D) have been carried out for production of molybdenum-99 ($$^{99}$$Mo) by (n, $$gamma$$) method, a parent nuclide of $$^{99m}$$Tc, with the Japan Material Testing Reactor (JMTR). On the other hand, the new project as "Domestic Production of Medical Radioisotope (Technetium preparation) in Japan" was adopted in the Tsukuba International Strategic Zone on October, 2013 and the demonstration tests will be planned for the domestic production of $$^{99}$$Mo/$$^{99m}$$Tc with the JMTR. Thus, new facilities and analysis devices were equipped in the JMTR Hot Laboratory in 2014 as the part of this project. As the part of the analytical device equipment, the $$gamma$$-TLC analyzer and the radiation detector connected with the High Performance Liquid Chromatography (HPLC) were installed for quality inspection of the $$^{99}$$Mo/$$^{99m}$$Tc solution and the extracted $$^{99m}$$Tc solution in the JMTR Hot Laboratory. The performance tests of these devices such as detection sensitivity, resolution, linearity and selectivity of energy range were carried out with $$^{137}$$Cs and $$^{152}$$Eu as alternative radionuclides of $$^{99}$$Mo and $$^{99m}$$Tc, respectively. In the results, bright prospects were obtained concerning the quality inspection of the $$^{99}$$Mo/$$^{99m}$$Tc and $$^{99m}$$Tc solutions using these devices. This report describes the results of those performance tests.

JAEA Reports

Determination of neptunium in neptunium-uranium-plutonium mixed oxide fuel by spectrophotometry.

; ; ; ; ; *; *

JNC TN8400 2001-026, 29 Pages, 2001/12

JNC-TN8400-2001-026.pdf:0.99MB

The measurement condition by spectrophotometry was evaluated to measure Np content in MOX fuel containing Np. The Np concentration was obtained by measuring the 727nm absorption peak, after the valence of Np in the sample solution was adjusted to the Np(Ⅳ). The calibration curve showed the linearity up to Np concentration 0.8mg/ml. Though Pu and U quantity were respectively added to the Np solution to 30 times and 60 times of Np concentration, there was no effect to the Np analysis. By using this method, relative standard deviation (RSD) of the analyzed values of Np content for 2%Np - MOX fuel was about 4%. In addition, It was confirmed that the Np content could be measured without separating Np from Pu and U. This method can be sufficiently applied as a quick simple method to analyze Np content in MOX fuel containing Np.

Journal Articles

Semiconductor radiation detectors and their measurement system

Katagiri, Masaki

Denki Gakkai Genshiryoku Kenkyukai Shiryo (NE-01-23), p.9 - 14, 2001/10

no abstracts in English

Journal Articles

Radiation detector using single crystal artificial diamond

Nishitani, Takeo

Isotope News, (569), p.2 - 4, 2001/10

no abstracts in English

JAEA Reports

Biosphere modeling with climate changes for safety assessment of high-level radioactive waste geological isolation

Kato, Tomoko; ; Suzuki, Yuji*; ; Ishiguro, Katsuhiko; Ikeda, Takao*; Richard, L.*

JNC TN8400 2001-003, 128 Pages, 2001/03

JNC-TN8400-2001-003.pdf:6.09MB

In the safety assessment of a high-level radioactive waste (HLW) disposal system, it is required to estimate radiological impacts on future human beings arising from potential radionuclide releases from a deep repository into the surface environment. In order to estimate the impacts, a biosphere model is developed by reasonably assuming radionuclide migration processes in the surface environment and relevant human lifestyles. Releases from the repository might not occur for many thousands of years after disposal. Over such timescales, it is anticipated that the considerable climatic change, for example, induced by the next glaciation period expected to occur in around ten thousand years from now, will have a significant influence on the near surface environment and associated human lifestyles. In case of taking these evolution effects into account in modeling, it is reasonable to develop several alternative models on biosphere evolution systems consistent with possible future conditions affected by expected climatic changes. In this study, alternative biosphere models were developed taking effects of possible climatie change into account. In the modeling, different climatic states existing in the world from the present climate condition in Japan are utilized as an analogy. Estimation of net effects of the climatic change on biosphere system was made by comparing these alternative biosphere models with a constant biosphere model consistent with the present climatic state through flux to dose conversion factors derived from each one.

Journal Articles

Diamond radiation detector made of an nultrahigh-purity type IIa diamond crystal grown by high-pressure and high-temperature synthesis

Tanaka, Teruya; Kaneko, Junichi; Takeuchi, Daisuke*; Sumiya, Hitoshi*; Katagiri, Masaki; Nishitani, Takeo; Takeuchi, Hiroshi; Iida, Toshiyuki*; Okushi, Hideyo*

Review of Scientific Instruments, 72(2), p.1406 - 1410, 2001/02

 Times Cited Count:8 Percentile:46.78(Instruments & Instrumentation)

no abstracts in English

JAEA Reports

A study on improvements in accuracy of nuclear data measurements using $$gamma$$-ray spectroscopic methods

Furutaka, Kazuyoshi

JNC TN8400 2000-028, 70 Pages, 2000/10

JNC-TN8400-2000-028.pdf:1.71MB

This report describes the study done by the author as a postdoctoral research associate at Japan Nuclear Cycle Development Institute. This report is divided into two parts: improvements in accuracy in determination of thermal neutron capture cross sections, and improvements in accuracy of photo-nuclear absorption cross section measurements using the HHS. (1)In the measurements of thermal neutron capture cross sections using an activation method, accuracies of the final results attained are limited by (1) accuracy of $$gamma$$-ray peak detection efficiencies, and (2) accuracies of $$gamma$$-ray emission probabilities. In this study; to determine thermal neutron capture cross sections more accurately, the following researches have been done using a newly developed three-dimensional coincidence measurement system: (1)accurate determination of $$gamma$$-ray standard sources using a $$gamma$$-$$gamma$$ coincidence method, for precise calibration of $$gamma$$-ray peak detection efficiency, and (2) development of a $$beta$$-$$gamma$$ coincidence measurement system using a plastic scintillation detector as a $$beta$$-ray detector, for the determination of $$gamma$$-ray emission probabilities of short-lived nuclides, and measurement of $$gamma$$-ray emission probabilities of $$^{100}$$Tc nuclide using the coincidence system. (2)To transform radioactive nuclides with small thermal neutron capture cross sections, use of photonuclear absorption reaction has been suggested. In order to transform these nuclides efficiently using the reaction, one has to know detailed behavior of the photo-absorption cross sections. In this study, a Monte-Carlo simulation code has been used to create a standard set of $$gamma$$-ray response functions of the high-resolution high-energy spectrometer (HHS), to enable reliable analyses of the data obtained by the spectrometer.

JAEA Reports

None

JNC TN4420 2000-009, 11 Pages, 2000/06

JNC-TN4420-2000-009.pdf:0.84MB

None

JAEA Reports

None

Iguchi, Tetsuo; Watanabe, Kenichi*; *; Nose, Shoichi; Harano, Hideki;

JNC TY9400 2000-019, 34 Pages, 2000/05

JNC-TY9400-2000-019.pdf:0.79MB

None

Journal Articles

High-temperature operation of a radiation detector made of a type IIa diamond single crystal synthesized by a HP/HT method

Tanimura, Yoshihiko; Kaneko, Junichi; Katagiri, Masaki; Ikeda, Yujiro; Nishitani, Takeo; Takeuchi, Hiroshi; Iida, Toshiyuki*

Nuclear Instruments and Methods in Physics Research A, 443(2-3), p.325 - 330, 2000/04

 Times Cited Count:36 Percentile:88.42(Instruments & Instrumentation)

no abstracts in English

JAEA Reports

None

*

JNC TJ6400 2000-007, 48 Pages, 1999/03

JNC-TJ6400-2000-007.pdf:1.23MB

None

Journal Articles

Response function measurement of a synthetic diamond radiation detector for 14 MeV neutrons

Kaneko, Junichi; Ikeda, Yujiro; Nishitani, Takeo; Katagiri, Masaki

Review of Scientific Instruments, 70(1), p.1100 - 1103, 1999/01

 Times Cited Count:22 Percentile:77.39(Instruments & Instrumentation)

no abstracts in English

Journal Articles

Development of a synthetic diamond radiation detector with a boron doped CVD diamond contact

Kaneko, Junichi; Katagiri, Masaki; Ikeda, Yujiro; Nishitani, Takeo

Nuclear Instruments and Methods in Physics Research A, 422, p.211 - 215, 1999/00

 Times Cited Count:24 Percentile:84.01(Instruments & Instrumentation)

no abstracts in English

JAEA Reports

None

PNC TJ1600 98-004, 50 Pages, 1998/03

PNC-TJ1600-98-004.pdf:1.63MB

no abstracts in English

Journal Articles

Development of radiation detectors using synthetic diamond crystals

Kaneko, Junichi; Katagiri, Masaki; Ikeda, Yujiro; Nishitani, Takeo

Advanced Materials'98;Advanced Materials Research Utilizing Extreme Conditions, p.257 - 260, 1998/00

no abstracts in English

Journal Articles

Optical fibers and their applications for radiation measurements

Kakuta, Tsunemi

Hoshasen, 24(1), p.41 - 48, 1998/00

no abstracts in English

JAEA Reports

Subcriticality measurement by Mihalczo method (II)

Hazama, Taira

PNC TN9410 97-093, 67 Pages, 1997/10

PNC-TN9410-97-093.pdf:1.63MB

Subcriticality measurement by Mihalczo method was investigated varying Cf source intensity and neutron background level. It is found that Cf source intensity must be chosen carefully when neutron background level is too high to be ignored compared to Cf source intensity. Under current measurement accuracy, the statistic error becomes double when the ratio of neutron background occupies 90% of all neutron sources in the system. On the other hand, under low neutron background level, Cf source intensity does not have any effect on the accuracy and error of measured keffs. Also investigated was the detector position dependence of meaured keffs. The detector fields of view for localy positioned detector was utilized to correct the dependence. When corrected, the measured keffs showed little dependence on detector position, which verified the validity of the correction method.

JAEA Reports

None

PNC TJ6622 97-001, 38 Pages, 1997/03

PNC-TJ6622-97-001.pdf:1.33MB

None

JAEA Reports

None

PNC TJ1615 97-002, 33 Pages, 1997/03

PNC-TJ1615-97-002.pdf:1.53MB

None

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