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Journal Articles

Systematic effects on cross section data derived from reaction rates in reactor spectra and a re-analysis of $$^{241}$$Am reactor activation measurements

$v{Z}$erovnik, G.*; Schillebeeckx, P.*; Becker, B.*; Fiorito, L.*; Harada, Hideo; Kopecky, S.*; Radulovic, V.*; Sano, Tadafumi*

Nuclear Instruments and Methods in Physics Research A, 877, p.300 - 313, 2018/01

 Times Cited Count:1 Percentile:38.14(Instruments & Instrumentation)

Methodologies to derive cross section data from spectrum integrated reaction rates were studied. The Westcott convention and some of its approximations were considered. The accuracy of the results strongly depends on the assumptions that are made about the neutron energy distribution, which is mostly parameterised as a sum of a thermal and an epi-thermal component. Resonance integrals derived from such data can be strongly biased. When the energy dependence of the cross section is known and information about the neutron energy distribution is available, a method to correct for a bias on the cross section at thermal energy is proposed. Reactor activation measurements to determine the thermal $$^{241}$$Am(n, $$gamma$$) cross section reported in the literature were reviewed, where the results were corrected to account for possible biases. These data combined with results of time-of-flight measurements give a capture cross section 720 (14) b for $$^{241}$$Am(n, $$gamma$$) at thermal energy.

Journal Articles

Characteristics of neutron resonance densitometry, 2; Neutron resonance capture analysis

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Kureta, Masatoshi; Becker, B.*; Kopecky, S.*; Heyse, J.*; Paradela, C.*; Mondelaers, W.*; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-36-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2015/12

Neutron Resonance Densitometry (NRD) was developed as a non-destructive assay to quantify U and Pu isotopes in particle-like debris. NRD is composed of neutron resonance transmission analysis (NRTA) and Neutron Resonance Capture Analysis (NRCA) or Prompt Gamma-ray Analysis (PGA). NRCA/PGA in NRD plays a role of identifying impurities in debris under the high-radiation field primarily caused by $$^{137}$$Cs. For this purpose, a novel LaBr$$_3$$ $$gamma$$-ray detector employing specific shields has been newly developed. With the developed $$gamma$$-ray detector, a demonstration NRCA experiment was performed at a neutron time of flight facility GELINA (Belgium). As a result, samples (Hf, Gd, Ni) placed in a black box that is completely sealed by third party were successfully identified by the experiment. This presentation explains the design concept of the $$gamma$$ ray detector including its detection principle and details of the demonstration NRCA experiment.

Journal Articles

Characteristics of neutron resonance densitometry, 1; Neutron resonance transmission analysis

Kitatani, Fumito; Harada, Hideo; Koizumi, Mitsuo; Tsuchiya, Harufumi; Kureta, Masatoshi; Becker, B.*; Kopecky, S.*; Heyse, J.*; Paradela, C.*; Mondelaers, W.*; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-36-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2015/12

From 2012 to 2014, Neutron Resonance Densitometry (NRD) is being developed as a non-destructive assay to quantify U and Pu isotopes. NRD is composed of neutron resonance transmission analysis (NRTA) and Neutron Resonance Capture Analysis (NRCA)/Prompt Gamma-ray Analysis (PGA). NRTA in NRD plays a role of quantifying the amounts of the isotopes of a nuclear fuel material (U, Pu) in molten fuel debris. Therefore, the neutron absorption measurement using Time-of-Flight (TOF) method is carried out. A demonstration NRTA experiment was performed at a neutron time of flight facility GELINA (Belgium). Consequently, we succeeded in iquantifying the randomly selected sample from Au, W, Rh, Nb, Cu. Co, Mn, B contained in a black box. In this presentation, we describe the principle of measurement of the developed NRTA and explain details of the demonstration experiment.

Journal Articles

Systematic effects on cross-section data derived from reaction rates at a cold neutron beam

$v{Z}$erovnik, G.*; Becker, B.*; Belgya, T.*; Genreith, C.*; Harada, Hideo; Kopecky, S.*; Radulovi$'c$, V.*; Sano, Tadafumi*; Schillebeeckx, P.*; Trkov, A.*

Nuclear Instruments and Methods in Physics Research A, 799, p.29 - 36, 2015/11

 Times Cited Count:4 Percentile:43.49(Instruments & Instrumentation)

The methodology to derive cross section data from measurements in a cold neutron beam was studied. Mostly, capture cross sections at thermal energy are derived relative to a standard cross section, and proportionality between the standard and the measured cross section is often assumed. Due to this assumption the derived capture cross section at thermal energy can be biased by more than 10%. Evidently the bias depends on how much the energy dependence of the cross section deviates from a direct proportionality with the inverse of the neutron speed. The effect is reduced in case the cross section is not derived at thermal energy but at an energy close to the average energy of the cold neutron beam. Nevertheless, it is demonstrated that the bias can only be avoided in case the energy dependence of the cross section is known and proper correction factors are applied. In some cases the results can also be biased when the attenuation of the neutron beam within the sample is neglected in the analysis. Some of the cross section data reported in the literature suffer from such bias effects.

Journal Articles

Generalized analysis method for neutron resonance transmission analysis

Harada, Hideo; Kimura, Atsushi; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Becker, B.*; Kopecky, S.*; Schillebeeckx, P.*

Journal of Nuclear Science and Technology, 52(6), p.837 - 843, 2015/06

 Times Cited Count:2 Percentile:66.76(Nuclear Science & Technology)

Journal Articles

NRD demonstration experiments at GELINA

Paradela, C.*; Alaerts, G.*; Becker, B.*; Harada, Hideo; Heyse, J.*; Kitatani, Fumito; Koizumi, Mitsuo; Kopecky, S.*; Mondelaers, W.*; Moens, A.*; et al.

EUR-27507-EN, 16 Pages, 2015/04

Journal Articles

Development of NRD, 2; Investigation on systematic effects due to sample thickness for areal density derived from NRTA

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Kimura, Atsushi; Becker, B.*; Kopecky, S.*; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-35-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2015/01

We are developing neutron resonance densitometry that combines neutron resonance transmission analysis (NRTA) and neutron resonance capture analysis. The aim is to establish a non-destructive technique that can quantify nuclear materials in particle-like debris of melted fuel resulting from severe nuclear accidents like the one at the Fukushima Daiichi Nuclear Power Plant. Systematic effects due to sample thickness and mixed sample for the areal density measurement by NRTA were investigated at a neutron time-of-facility GELINA, IRMM. The experiments were conducted utilizing natural Cu metal discs with different thickness and a B$$_{4}$$C disc. Areal densities were derived with a resonance shape analysis code REFIT. It was found that they were inconsistent with those calculated by mass and area, when using recommended resonance parameters. Hence, a neutron width of resonance parameters was newly evaluated with the NRTA data and we found that derived areal density agreed within 2% with the expected ones. We also discuss the impacts of mixed sample for the areal density derived from NRTA measurement.

Journal Articles

Development of NRD, 1; Developments of a LaBr$$_{3}$$ scintillation detector system for neutron resonance densitometry

Koizumi, Mitsuo; Tsuchiya, Harufumi; Kitatani, Fumito; Harada, Hideo; Takamine, Jun; Kureta, Masatoshi; Seya, Michio; Kimura, Atsushi; Iimura, Hideki; Becker, B.*; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-35-Kai Nenji Taikai Rombunshu (Internet), 8 Pages, 2015/01

We have proposed neutron resonance densitometry (NRD) as a method to quantify special nuclear materials in particle-like debris of melted fuel. NRD is a combination of neutron resonance transmission analysis (NRTA), and neutron resonance capture analysis (NRCA) (and prompt $$gamma$$-ray analysis (PGA)). NRCA/PGA is used to identify contaminant elements, which is difficult to be detected by NRTA. To observe $$gamma$$ rays emitted in neutron capture reaction, a spectrometer consisting of LaBr$$_3$$ scintillation detectors has been constructed. A newly installed data acquisition system enables us to measure 500 k event/s for each 8-channel inputs. In this presentation, the research and development of NRD is introduced and the status of the development of the spectrometer system is given as well.

Journal Articles

Neutron resonance spectroscopy for the characterization of materials and objects

Schillebeeckx, P.*; Becker, B.*; Harada, Hideo; Kopecky, S.*

Landolt-B$"o$rnstein Group 1, Vol.26; Numerical Data and Functional Relationships in Science and Technology, Subv.A; Neutron Resonance Parameters, p.4 - 52, 2015/00

The probability that neutrons interact with nuclei strongly depends on the energy of the incoming neutron. There are resonances at specific energies for each nuclide.Since resonances appear at energies that are specific for each nuclide, they can be used to determine the elemental and in some cases even the isotopic composition of materials and objects. The resonance structures in total and capture cross sections are the basis of Neutron Resonance Transmission Analysis (NRTA) and Neutron Resonance Capture Analysis (NRCA), respectively. Principles of NRTA and NRCA are reviewed. Neutron Resonance Densitometry (NRD) combining NRTA and NTCA is also reviewed as a non-destructive method to characterize particle-like debris of melted fuel.

Journal Articles

Recent progress in research and development in neutron resonance densitometry (NRD) for quantification of nuclear materials in particle-like debris

Koizumi, Mitsuo; Kitatani, Fumito; Tsuchiya, Harufumi; Harada, Hideo; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Seya, Michio; Becker, B.*; Kopecky, S.*; et al.

Nuclear Back-end and Transmutation Technology for Waste Disposal, p.13 - 20, 2015/00

Neutron Resonance Densitometry (NRD) has been proposed for quantification of nuclear materials in melted fuel. NRD is a combined TOF technique of Neutron Resonance Transmission Analysis (NRTA) and Neutron Resonance Capture Analysis (NRCA) or Prompt Gamma ray Analysis (PGA). To establish the method, development of detectors is in progress. Experiments were carried out at a TOF facility, GELINA, under the collaboration with EC-JRC-IRMM. The progress of the project is reported.

Journal Articles

Impact of systematic effects on results of neutron resonance transmission analysis

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Kimura, Atsushi; Becker, B.*; Kopecky, S.*; et al.

Nuclear Instruments and Methods in Physics Research A, 767, p.364 - 371, 2014/12

 Times Cited Count:6 Percentile:36.56(Instruments & Instrumentation)

The impact of systematic effects on the areal density derived from a neutron resonance transmission analysis (NRTA) is investigated by measurements at the time-of-flight facility GELINA. The experiments were carried out at a 25 m station using metallic natural Cu discs with different thicknesses. To derive the areal density from a fit to the experimental transmission, the resonance shape analysis code REFIT was used. Large bias effects were observed using recommended resonance parameters. Therefore, neutron resonance parameters, in particular resonance energies and neutron widths, were derived from the transmission data obtained with a 0.25 mm thick Cu metallic sample. These parameters were used to study the impact of the resonance strength and sample thickness, on the accuracy of the areal density derived by NRTA.

Journal Articles

Thickness and mixed sample effects on areal density measurement with NRTA for particle like debris of melted fuel

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Kimura, Atsushi; Becker, B.*; Kopecky, S.*; et al.

Proceedings of INMM 55th Annual Meeting (Internet), 6 Pages, 2014/07

Journal Articles

Developments of a LaBr$$_3$$ scintillation detector system for neutron resonance densitometry (NRD)

Koizumi, Mitsuo; Tsuchiya, Harufumi; Kitatani, Fumito; Harada, Hideo; Takamine, Jun; Kureta, Masatoshi; Seya, Michio; Kimura, Atsushi; Iimura, Hideki; Becker, B.*; et al.

Proceedings of INMM 55th Annual Meeting (Internet), 7 Pages, 2014/07

Journal Articles

Development of neutron resonance densitometry

Harada, Hideo; Schillebeeckx, P.*; Tsuchiya, Harufumi; Kitatani, Fumito; Koizumi, Mitsuo; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Kimura, Atsushi; Seya, Michio; et al.

Proceedings of INMM 55th Annual Meeting (Internet), 8 Pages, 2014/07

Journal Articles

Measurement of the direct particle transport through stochastic media using neutron resonance transmission analysis

Becker, B.*; Kopecky, S.*; Harada, Hideo; Schillebeeckx, P.*

European Physical Journal Plus (Internet), 129(4), p.58_1 - 58_9, 2014/04

 Times Cited Count:11 Percentile:28.13(Physics, Multidisciplinary)

Journal Articles

Neutron resonance densitometry for particle-like debris of melted fuel

Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Takamine, Jun; Kureta, Masatoshi; Tsuchiya, Harufumi; Iimura, Hideki; Seya, Michio; Becker, B.*; Kopecky, S.*; et al.

Nuclear Data Sheets, 118, p.502 - 504, 2014/04

 Times Cited Count:3 Percentile:63.98(Physics, Nuclear)

Journal Articles

Particle size inhomogeneity effect on neutron resonance densitometry

Becker, B.*; Harada, Hideo; Kauwenberghs, K.*; Kitatani, Fumito; Koizumi, Mitsuo; Kopecky, S.*; Moens, A.*; Schillebeeckx, P.*; Sibbens, G.*; Tsuchiya, Harufumi

ESARDA Bulletin, (50), p.2 - 8, 2013/12

Journal Articles

Development of neutron resonance densitometry at the GELINA TOF facility

Schillebeeckx, P.*; Abousahl, S.*; Becker, B.*; Borella, A.*; Emiliani, F.*; Harada, Hideo; Kauwenberghs, K.*; Kitatani, Fumito; Koizumi, Mitsuo; Kopecky, S.*; et al.

ESARDA Bulletin, (50), p.9 - 17, 2013/12

Journal Articles

Investigation on sample thickness effect on nuclear material quantification with NRTA for particle-like debris of melted fuel

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Becker, B.*; Kopecky, S.*; Kauwenberghs, K.*; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 8 Pages, 2013/10

We have no established methods to quantify the amount of nuclear materials in particle-like debris of melted fuel derived from a nuclear accident such as the one occurred at the Fukushima Daiichi Nuclear Power Plant. For this reason, neutron resonance densitometry, combining neutron resonance transmission analysis and neutron resonance capture analysis, is under development. It is expected that such debris have a wide variety of size, shape, and concentration of impurities. Experiments with the Neutron Resonance Transmisson Analysis (NRTA) using three Cu metal disks with different thickness of 0.125 mm, 0.25 mm, and 0.7 mm were made between November 2012 and February 2013 at the Geel Electron LINear Accelerator (GELINA) to investigate sample thickness effect on the transmission analysis. We experimentally derived the areal density for the individual Cu samples with the resonance shape analysis code REFIT, and then compared them with the declared areal density. It was found that the REFIT-evaluated areal density was consistent with declared ones for each sample.

Journal Articles

Recent progress in research and development on the neutron resonance densitometry for particle-like debris of melted fuel

Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Seya, Michio; Becker, B.*; Kopecky, S.*; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 6 Pages, 2013/10

Neutron resonance densitometry (NRD) has been proposed to quantify nuclear materials in particle-like debris of melted fuel formed in severe accidents of nuclear reactors such as Fukushima Daiichi Nuclear Power Plants. NRD is a method combining NRTA (neutron resonance transmission analysis) and NRCA (neutron resonance capture analysis). It relies on neutron TOF (time of flight) technique using a pulsed white neutron source. The use of a special $$gamma$$-ray spectrometer for NRCA and an evaluation of the achievable accuracy are discussed. The discussion is based on results of Monte Carlo simulations combined experimental data from measurements carried out at GELINA. In this contribution, progress made in the development of NRD for the characterization of nuclear materials mixed with highly radioactive nuclides is presented, together with the basic concept and principles.

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