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Liquid Oxygen Slab TOF Experiment (FNS/JAERI)

1. Name of Experiment:
 FNS/JAERI Time-of-Flight Experiment on Liquid Oxygen Slab With 14 MeV D-T
 Neutrons (1989)

2. Purpose and Phenomena Tested:
 The angular neutron spectra leaking from the 200 mm slab of liquid Oxygen
 were measured at several angles.

3. Description of Source and Experimental Configuration:
 The pulsed beam line of the intense 14 MeV neutron source facility at
 Fusion Neutronic Source (FNS) at JAERI was used. The D-T neutrons were
 produced by bombarding the tritium-titanium target with 350 keV deuteron
 beam. The energy spectrum of the neutron source is given in Table 2.

 The slab assembly of liquid gas was set at the distance of 200 mm from the
 D-T neutron source. The assembly is made of a cylinder with a double wall
 for for thermal insulation. The void between the walls was evacuated.
 Aluminum foil layers between the walls were inserted to prevent the thermal
 radiation heating. The central area of the container walls was made of very
 thin windows of 300 and 465 mm in diameter to reduce neutron scattering for
 measuring angles. The thickness of the inner cylinder is 200 mm and the
 diameter 600 mm. The details of the container geometry are shown in Figure 1.

 The atom density of Oxygen is 4.2947E-2 atoms/barn.cm.

4. Measurement System:
 The neutron spectra were measured with the time-of-flight (TOF) technique.
 A cylindrical NE213 scintillator (50.8 mm-diameter, 50.8 mm-long) was
 used as a neutron detector. The aperture size of the collimator was such
 that the scintillator detected only neutrons leaking from the central
 area of the slab surface behind the source. The scintillators were
 located about 7 m (see Table 1) from the cylindrical slab and at angles
 of 0, 12.2, 24.9, 41.8, and 66.8 degrees with respect to the deuteron beam
 axis. The energy range between 0.05 and 15 MeV was measured by combination
 of two bias schemes described in [2]. The details of the experimental
 set-up are shown on Figure 2.

5. Description of Results and Analysis:
 The measured angular neutron flux spectra are given in Table 3.
 The spectra were calculated from the following expression (see Figure 3
 for definitions):


 where C(E) is detected neutron counts, eps(E) the neutron detection
 efficiency, dOmega the solid angle subtended by the detector to the point
 on the center of slab surface (=Ad/L*L, where Ad=detector area and
 L=distance from the slab surface to the detector), As is the effective
 measured area defined by the detector-collimator system on the plane
 perpendicular to its axis, Sn number of source neutrons emitted from the
 D-T target, and T(E) the attenuation correction due to scattering in air.

 Error Assessment:
 The experimental errors in the measured neutron spectra include only
 statistical deviation (1 sigma).

 Example of Experiment Analysis:
 The sample input for the MCNP-4B code in ref. [10] is given in file
 mcnp4b.inp. The calculations were performed using ENDF/B-VI Rev.1 data
 from the original MCNP library. The results for the neutron spectrum
 calculation are compared with the measurements in Figures 5 and 6 for
 different angles.

 The sample input for the DOT-3.5 code taken from ref. [9] is given in
 file dot35.inp. For the description of the calculational procedure see
 ref. [4] and [8].

6. Special Features:

7. Author/Organizer:
 Experiment and analysis:
 Yukio OYAMA and Hiroshi MAEKAWA
 Japan Atomic Energy Research Institute
 Tokai-mura, Naka-gun, Ibaraki-ken, 319-1195 Japan
 Phone: 81-292-82-6809 (for Y.O.) or -6015 (for H.M.)
 Fax: 81-292-82-5996 (for Y.O.) or -6365 (for H.M.)
 e-mail: oyama@cens.tokai.jaeri.go.jp
 or maekawa@fnshp.tokai.jaeri.go.jp

 Compiler of data for Sinbad:
 I. Kodeli
 Institute Jozef Stefan, Jamova 39, 1000 Ljubljana, Slovenia
 E-mail: Ivan.Kodeli@ijs.si

 Reviewer of compiled data:
 A. Trkov
 Institute Jozef Stefan, Jamova 39, 1000 Ljubljana, Slovenia
 E-mail: Andrej.Trkov@ijs.si

 F. Maekawa
 JAERI, Tokai-mura, Naka-gun, Ibaraki-ken, 319-1195 JAPAN
 E-mail: fujio@fnshp.tokai.jaeri.go.jp

8. Availability:

9. References:

 [1] Oyama Y., Maekawa H.: "Measurement and Analysis of an Angular Neutron
 Flux on a Beryllium Slab Irradiated with Deuteron-Tritium Neutrons,"
 Nucl. Sci. Eng., 97, 220-234 (1987).
 [2] Oyama Y., Yamaguchi S., Maekawa H.: "Experimental Results of Angular
 Neutron Flux Spectra Leaking from Slabs of Fusion Reactor Candidate
 Materials (I)," JAERI-M 90-092 (1990).
 [3] Oyama Y., Maekawa H.: "Measurements of Angle-Dependent Neutron
 Spectra from Lithium-Oxide Slab Assemblies by Time-of-Flight Method,"
 JAERI-M 83-195 (Nov. 1983).
 [4] Oyama Y., Yamaguchi S., Maekawa H.: "Analysis of Time-of-Flight
 Experiment on Lithium-Oxide Assemblies by a Two-Dimensional
 Transport Code DOT3.5," JAERI-M 85-031 (March 1985).
 [5] Oyama Y., Maekawa H.: "Spectral Measurement of Angular Neutron Flux on
 the Restricted Surface of Slab Assemblies by the Time-of-Flight Method,"
 Nucl. Instr. Methods, A245 173-181 (1986).
 [6] Oyama Y., Yamaguchi S., Maekawa H.: "Measurements and Analyses of
 Angular Neutron Flux Spectra on Graphite and Lithium-Oxide Slabs
 Irradiated with 14.8 MeV Neutrons," J. Nucl. Sci. Technol., 25,
 419-428 (1988).
 [7] Oyama Y., Kosako K., Maekawa H.: "Measurements and Analyses of
 Angular Neutron Flux Spectra on Liquid Nitrogen, Liquid Oxygen and
 Iron Slabs," Proc. Int'l Conf. on Nuclear Data for Science and
 Technology, 13-17 May, Juelich (1991).
 [8] Oyama Y., Kosako K., Maekawa H.: "Measurement and Calculations of
 Angular Neutron Flux Spectra Leaking from Slabs Bombarded with 14.8 MeV
 Neutrons," Nucl. Sci. Eng., 115, 24-37 (1993)
 [9] International Atomic Energy Agency, Nuclear Data Section:
 Compilation for FENDL benchmarks,
 [10] Fujio Maekawa, Masayuki Wada, Chihiro Ichihara, Yo Makita,
 Akito Takahashi, Yukio Oyama:
 Compilation of Benchmark Results for Fusion Related Nuclear Data,
 JAERI-Data/Code 98-024, Nov. 1998.

10. Data and Format:

 FILE bytes Description NAME
 ---- ----- ---------------------------------------------------- ------------
 1 10.628 This information file fnso-abs htm
 2 46.830 Description of Experiment and Results fnso-exp htm
 3 9.842 Input data for MCNP-4B 3D calculations mcnp4b inp
 4 19.177 Input data for GRTUNCL/DOT-3.5 2D calculations dot35 inp
 5 177.379 Fig. 1: Vacuum thermal insulating container geometry fnso-f1 tif
 6 11.156 Fig. 1: Vacuum thermal insulating container geometry fnso-f1 gif
 7 15.149 Fig. 2: Experimental setup for TOF Experiment fnso-f2 gif
 8 8.203 Fig. 3: Definition of parameters for flux calculation fnso-f3 gif
 9 9.445 Fig. 4: Calculational geometry for MCNP fnso-f4 gif
 10 54.896 Fig. 5: Measured vs. MCNP4B (ENDF/B-VI) spectra fnso-f5 gif
 11 131.031 Fig. 6: Measured vs. MCNP4B (ENDF/B-VI) spectra fnso-f6 pdf
 12 7.028.305 Reference j90-092.pdf
 13 4.077.259 Reference j83-195.pdf
 14 975.835 Reference j85-031.pdf
 15 253.594 Reference ndst91.pdf
 16 1.325.531 Reference nse115-93.pdf
 17 7.518.191 Reference j98-024.pdf

 The file fnso-exp.htm contains the following tables:

 Tab. 1: Flight path and measured area
 Tab. 2: A table with the source neutron spectrum from ref.[9].
 Tab. 3: Measured angular neutron spectra from ref.[9]
 (0, 12.2, 24.9, 41.8 and 66.8 deg.).

 Figures are included in TIFF format using LZW compression and GIF format (preview).

SINBAD Benchmark Generation Date: 08/2000
SINBAD Benchmark Last Update: 08/2000