• Title/Summary/Keyword: Neutron spectroscopy

Search Result 69, Processing Time 0.025 seconds

Neutron and gamma-ray energy reconstruction for characterization of special nuclear material

  • Clarke, Shaun D.;Hamel, Michael C.;Di fulvio, Angela;Pozzi, Sara A.
    • Nuclear Engineering and Technology
    • /
    • v.49 no.6
    • /
    • pp.1354-1357
    • /
    • 2017
  • Characterization of special nuclear material may be performed using energy spectroscopy of either the neutron or gamma-ray emissions from the sample. Gamma-ray spectroscopy can be performed relatively easily using high-resolution semiconductors such as high-purity germanium. Neutron spectroscopy, by contrast, is a complex inverse problem. Here, results are presented for $^{252}Cf$ and PuBe energy spectra unfolded using a single EJ309 organic scintillator; excellent agreement is observed with the reference spectra. Neutron energy spectroscopy is also possible using a two-plane detector array, whereby time-of-flight kinematics can be used. With this system, energy spectra can also be obtained as a function of position. Spatial-dependent energy spectra are presented for neutron and gamma-ray sources that are in excellent agreement with expectations.

Diamond-based neutron scatter camera

  • Alghamdi, Ahmed;Lukosi, Eric
    • Nuclear Engineering and Technology
    • /
    • v.54 no.4
    • /
    • pp.1406-1413
    • /
    • 2022
  • In this study, a diamond-based neutron scatter camera (DNSC) was developed for neutron spectroscopy in high flux environments. The DNSC was evaluated experimentally and through simulations. It was simulated using several Monte Carlo codes in a two-array layout. The two-array model included two diamond detectors. The simulation reconstructed the spectra of 252Cf and 239Pu-Be neutron sources with high accuracy (~93%). The two-diamond array system was experimentally evaluated, demonstrating the neutron spectroscopy capabilities of the DNSC. The reconstructed spectrum of the 239Pu-Be source manifested the characteristic peaks of the source. The advantage of a DNSC over a NSC is its ability to define any neutron double-scattering events without the need to absorb incident neutrons in the second detector, and atomic recoil energy information is not needed to determine the incident neutron energy.

Neutron spectroscopy using pure LaCl3 crystal and the dependence of pulse shape discrimination on Ce-doped concentrations

  • Vuong, Phan Quoc;Kim, Hongjoo;Luan, Nguyen Thanh;Kim, Sunghwan
    • Nuclear Engineering and Technology
    • /
    • v.53 no.11
    • /
    • pp.3784-3789
    • /
    • 2021
  • We report a simple technique for direct neutron spectroscopy using pure LaCl3 crystals. Pure LaCl3 crystals exhibit considerably better pulse shape discrimination (PSD) capabilities with relatively good energy resolution as compared with Ce-doped LaCl3 crystals. Single crystals of pure and Ce-doped LaCl3 were grown using an inhouse-developed Bridgman furnace. PSD capabilities of these crystals were investigated using 241Am and 137Cs sources. Fast neutron detection was tested using a252Cf source and three separate bands corresponding to electron, proton, and alpha were observed. The proton band induced by the 35Cl(n,p)35S reaction can be used for direct neutron spectroscopy because proton energy is proportional to incident neutron energy. Owing to good scintillation performance and excellent PSD capabilities, pure LaCl3 is a promising candidate for space detectors and other applications that necessitate gamma/fast neutron discrimination capability.

Electrical characteristics and deep-level transient spectroscopy of a fast-neutron-irradiated 4H-SiC Schottky barrier diode

  • Junesic Park;Byung-Gun Park;Hani Baek;Gwang-Min Sun
    • Nuclear Engineering and Technology
    • /
    • v.55 no.1
    • /
    • pp.201-208
    • /
    • 2023
  • The dependence of the electrical characteristics on the fast neutron fluence of an epitaxial 4H-SiC Schottky barrier diode (SBD) was investigated. The 30 MeV cyclotron was used for fast neutron irradiation. The neutron fluences evaluated through Monte Carlo simulation were in the 2.7 × 1011 to 1.45 × 1013 neutrons/cm2 range. Current-voltage and capacitance-voltage measurements were performed to characterize the samples by extracting the parameters of the irradiated SBDs. Neutron-induced defects in the epitaxial layer were identified and quantified using a deep-level transient spectroscopy measurement system developed at the Korea Atomic Energy Research Institute. As the neutron fluence increased from 2.7 × 1011 to 1.45 × 1013 neutrons/cm2, the concentration of the Z1/2 defects increased by approximately 20 times. The maximum defect concentration was estimated as 1.5 × 1014 cm-3 at a neutron fluence of 1.45 × 1013 neutrons/cm2.

Structural and component characterization of the B4C neutron conversion layer deposited by magnetron sputtering

  • Jingtao Zhu;Yang Liu;Jianrong Zhou;Zehua Yang;Hangyu Zhu;Xiaojuan Zhou;Jinhao Tan;Mingqi Cui;Zhijia Sun
    • Nuclear Engineering and Technology
    • /
    • v.55 no.9
    • /
    • pp.3121-3125
    • /
    • 2023
  • Neutron conversion detectors that use 10B-enriched boron carbide are feasible alternatives to 3He-based detectors. We prepared boron carbide films at micron-scale thickness using direct-current magnetron sputtering. The structural characteristics of natural B4C films, including density, roughness, crystallization, and purity, were analyzed using grazing incidence X-ray reflectivity, X-ray diffraction, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and scanning electron microscopy. A beam profile test was conducted to verify the practicality of the 10B-enriched B4C neutron conversion layer. A clear profile indicated the high quality of the neutron conversion of the boron carbide layer.

Thermal-annealing behavior of in-core neutron-irradiated epitaxial 4H-SiC

  • Junesic Park ;Byung-Gun Park;Gwang-Min Sun
    • Nuclear Engineering and Technology
    • /
    • v.55 no.1
    • /
    • pp.209-214
    • /
    • 2023
  • The effect of thermal annealing on defect recovery of in-core neutron-irradiated 4H-SiC was investigated. Au/SiC Schottky diodes were manufactured using a 4H-SiC epitaxial wafer that was neutron-irradiated at the HANARO research reactor. The electrical characteristics of their epitaxial layers were analyzed under various conditions, including different neutron fluences (1.3 × 1017 and 2.7 × 1017 neutrons/cm2) and annealing times (up to 2 h at 1700 ℃). Capacity-voltage measurements showed high carrier compensation in the neutron-irradiated samples and a recovery tendency that increased with annealing time. The carrier density could be recovered up to 77% of the bare sample. Deep-level-transient spectroscopy revealed intrinsic defects of 4H-SiC with energy levels 0.47 and 0.68 eV below the conduction-band edge, which were significantly increased by in-core neutron irradiation. A previously unknown defect with a high electron-capture cross-section was discovered at 0.36 eV below the conduction-band edge. All defect concentrations decreased with 1700 ℃ annealing; the decrease was faster when the defect level was shallow.

Development of Neutron Induced Prompt γ-ray Spectroscopy System Using 252Cf (252Cf 선원을 이용한 즉발감마선 계측시스템 구성)

  • Park, Yong-Joon;Song, Byung-Chul;Jee, Kwang-Yong
    • Analytical Science and Technology
    • /
    • v.16 no.1
    • /
    • pp.12-24
    • /
    • 2003
  • For the design and set-up of neutron induced prompt ${\gamma}$-ray spectroscopy system using $^{252}Cf$ neutron source, the effects of shielding and moderator materials have been examined. The $^{252}Cf$ source being used for TLD badge calibration in Korea Atomic Energy Research Institute was utilized for this preliminary experiment. The ${\gamma}$-ray background and prompt ${\gamma}$-ray spectrum of the sample containing Cl were measured using HPGe (GMX 60% relative efficiency) located at the inside of the system connected to notebook PC at the outside of the system (about 20 meter distance). The background activities of neutron and ${\gamma}$-rays were measured with neutron survey meter as well as ${\gamma}$-ray survey meters, respectively and the system was designed to minimize the activities. Prompt ${\gamma}$-ray spectrum was measured using ${\gamma}$-${\gamma}$ coincident system for reduce the background and the continuum spectrum. The optimum system was designed and set up using the experimental data obtained.

Study in Background Reduction for the Neutron Induced Prompt Gamma-ray Spectroscopy

  • Song, Byoung-Chul;Jee, Kwang-Yong;Park, Yong-Joon
    • Proceedings of the Korean Radioactive Waste Society Conference
    • /
    • 2004.06a
    • /
    • pp.433-433
    • /
    • 2004
  • Neutron induced prompt gamma-ray spectroscopy (NIPS) system measures the prompt gamma-ray, emitting by the interaction of a neutron with various materials. This system will be of great benefit to scientists worldwide, since it provides the non-destructive measurement of many elements in either solid or liquid wastes. A NIPS facility has been developed in Nuclear Chemistry Research Division, at Korea Atomic Energy Research Institute (KAERI) with the aim of analyzing the major component elements in both aqueous and solid samples.(omitted)

  • PDF

Neutron diagnostics using nickel foil activation analysis in the KSTAR

  • Chae, San;Lee, Jae-Yong;Kim, Yong-Soo
    • Nuclear Engineering and Technology
    • /
    • v.53 no.9
    • /
    • pp.3012-3017
    • /
    • 2021
  • The spatial distribution and the energy spectrum of the neutron yield were investigated with the neutron activation analysis and MCNP simulation was carried out to verify the analysis results and to extend the results to a 3D mapping of the neutron yield distribution in the KSTAR. High purity Ni specimen was selected in the neutron activation analysis. Total neutron yields turned out to be 3.76 × 1012 n/s - 7.56 × 1012 n/s at the outer vessel of the KSTAR, two orders of magnitude lower than those at the inner vessel of the KSTAR, which demonstrates the attenuation of neutron yield while passing through the different structural materials of the reactor. Based on the fully expanded 3D simulation results, 2D cross-sectional distributions of the neutron yield on XY and ZX planes of KSTAR were examined. The results reveal that the neutron yield has its maximum concentration near the center of blanket and decreases with increasing proximity to the vacuum vessel wall.