MCNPX Benchmark Experiment Number 5 Rev. 0.0.1 <br>Neutron Production from Thick Targets of Carbon, Iron, Copper, and Lead by 30- and 52-MeV Protons(1982)

SINBAD ABSTRACT NEA-1552/30

MCNPX Benchmark Experiment Number 5 Rev. 0.0.1
Neutron Production from Thick Targets of Carbon, Iron, Copper, and Lead by 30- and 52-MeV Protons(1982)

1. Name of Experiment:
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Measurements of angular neutron spectra produced from 30- and 52-MeV protons striking thick targets of various materials, performed
at the University of Tokyo and the University of Osaka

2. Purpose and Phenomena Tested:
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A series of experiments performed at the University of Tokyo and the University of Osaka measured the angular neutron spectra
produced from 30- and 52-MeV protons striking thick targets of various materials. The results of these benchmark experiments
were reported by Nakamura [1,2] et al. for 30- and 52-MeV protons incident on carbon, iron, copper, and lead targets. Nakamura
reported secondary neutron spectra at several angles, as well as total neutron yield. The targets used in these experiments were
about twice the range of an incident proton so that the proton beam was completely stopped. The targets were sufficiently thin
so that the neutrons had negligible interaction within the targets.

3. Description of Source and Experimental Configuration:
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The SF cyclotron of the Institute for Nuclear Study (INS) at the University of Tokyo was used to produce a 30-MeV proton beam
that bombarded carbon, iron, copper, and lead targets. The targets were arranged perpendicular to the beam. A diagram of the SF
cyclotron is shown in Fig. 1. The targets were 20-mm in diameter, with thickness and densities as shown in Table 1.

A 52-MeV proton beam at the FM-cyclotron at the Institute for Nuclear Study at the University of Tokyo was also used to bombard thick
targets of carbon, iron, copper, and lead. A diagram of the FM cyclotron is shown in Fig. 2. The proton beam passed through a 0.15 mm
thick stainless steel window, then impinged on the targets given in Table 1.

4. Measurement System:
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The secondary neutrons produced by the 30-MeV proton beam were measured at angles of 0, 15, 30, 45, 75, and 135 degrees using a
7.62-cm-diameter x 7.62-cm-long NE 213 scintillator placed 4.03 m from the target.
The secondary neutrons produced by the 52-MeV proton beam were measured at angles of 0, 15, 30, 45, and 75 degrees using a
5.08-cm-diameter x 5.08-cm-long NE 213 organic liquid scintillator and iron and aluminum activation detectors. The neutron
pulse-height distributions from the NE 213 detector were converted to the neutron spectrum using the FERDO unfolding code and
calculated response functions[3].

5. Description of Results and Analysis:
-----------------------------------
The experimentally measured energy spectrum of neutrons produced from 30-MeV protons at various angles is shown in Figures
3, 4, 5, and 6 for the carbon, iron, copper, and lead targets, respectively. The data given in these graphs have been
digitized and are provided in Tables 2, 3, 4, and 5 for the carbon, iron, copper, and lead targets respectively.
The measured angular distributions of neutrons integrated from 3-MeV to 30-MeV from 30-MeV protons on the carbon, iron, copper, and
lead targets are given in Table 6, and are shown in Figure Figure 7.
The experimentally measured energy spectrum of neutrons produced from 52-MeV protons at various angles is shown in Figures
8, 9, 10, and 11 for the carbon, iron, copper, and lead targets, respectively. The data given in these graphs have been
digitized and are provided in Tables 7, 8, 9, and 10 for the carbon, iron, copper, and lead targets respectively.
The measured angular distributions of neutrons integrated from 5-MeV to 52-MeV from 52-MeV protons on the carbon, iron, copper, and
lead targets are given in Table 11, and are shown in Figure 12.
The experimental uncertainties are shown in the figures and have been digitized and are given in the data tables. The uncertainties
in the angular neutron spectrum for the 52-MeV experiments is not given for every data point, but are provided every fifth energy bin.

These 30- and 52-MeV angular neutron production experiments were modeled with the high energy particle transport code MCNPX[5]. The
new 150-MeV cross section set, LA150, was used in each of these calculations[6].
The computational model for the experiments consisted of a parallel beam of protons impinging upon the targets. The proton energy was
30-MeV for the SF cyclotron experiments and 52-MeV for the FM cyclotron experiments.
The 0.15 mm thick stainless steel window was included in the model of the FM cyclotron experiment. The target was surrounded by a sphere
of air. Current tallies were performed on the spherical surface in angular intervals and the results converted to neutrons per steradian
per proton for comparison with the experimental results.
Performing tallies at small solid angles covering the same solid angle as the detector would have required excessively long run times to
obtain acceptable statistical error.
The composition of the stainless steel window is assumed to be Stainless Steel 316 and its composition is given by Reference 4.
The Hybrid MPM option in MCNPX provided the best results for the 52-MeV proton calculations. For the 30-MeV proton calculations the best
results were provided with Bertini INC without preequilibrium.
The calculated angular neutron spectra are plotted against the measured neutron spectra in Figures 13, 14, 15, and 16 for 30-MeV protons
incident on carbon, iron, copper, and lead targets respectively.
The calculated angular distributions of neutrons integrated from 3-MeV to 30-MeV from 30-MeV protons on the carbon, iron, copper, and
lead targets are shown in Figure 17.
In order to make a simple comparison with the calculated neutron spectra and the measured neutron spectra the ratios of calculated to measured
total neutron yield for fast neutrons from 30-MeV protons on carbon, iron, copper, and lead have been calculated.

The calculated angular neutron spectra are plotted against the measured neutron spectra in Figures 18, 19, 20, and 21 for 52-MeV protons
incident on carbon, iron, copper, and lead targets respectively.
The calculated angular distributions of neutrons integrated from 5-MeV to 52-MeV from 52-MeV protons on the carbon, iron, copper, and lead
targets are shown in Figure 22.
In order to make a simple comparison with the calculated neutron spectra and the measured neutron spectra the ratios of calculated to measured
total neutron yield for fast neutrons from 52-MeV protons on carbon, iron, copper, and lead have been calculated.

6. Special Features:
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None

7. Author/Organizer:
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Experiment and analysis:

Compiler of data for Sinbad:
B. Maidou
URANUS, 78 470 St R�my les Chevreuse, France

Screened by:
I. Kodeli
OECD/NEA, 12 bd des Iles, 92130 Issy les Moulineaux, France

8. Availability:
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Unrestricted

9. References:
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[1] Nakamura T., Fujii M., and Shin K., "Neutron Production from Thick Targets of Carbon, Iron, Copper,
and Lead by 30- and 52-MeV Protons," Nuclear Science and Engineering, Vol. 83, 444-458 (1983).

[2] Nakamura T., Yoshida M., and Shin K., "Spectral Measurements of Neutrons and Photons from Thick
Targets of C, Fe, Cu, and Pb by 52 MeV Protons," Nuclear Instruments and Methods, 151, 493-503 (1978).

[3] Shin K., Uwamino Y., and Hyodo T., Nucl. Technol., 53, 78 (1981).

[4] O'Dell R. "Specification and Atom Densities of Selected Materials" in Criticality Calculations with
MCNP: A Primer, LA-12827-M, August 1994.

[5] H. Grady Hughes, Richard E. Prael, and Robert C. Little.: "MCNPX - The LAHET/MCNP Code Merger." Los
Alamos National Laboratory Memorandum XTM-RN(U) 97-012, April 22, 1997.

[6] M.B. Chadwick, P.G. Young, S. Chiba, S.C. Frankle, G.M. Hale, H.G. Hughes, A.J. Koning, R.C.
Little, R.E. MacFarlane, R.E. Prael and L.S. Waters. Cross Section Evaluations to 150 MeV for
Accelerator-driven Systems and Implementation in MCNPX. Nucl. Sci. and Eng., 131(3),
p. 293, March 1999.

10. Data and Format:
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DETAILED FILE DESCRIPTIONS
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Filename Size[bytes] Content
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1 30-52-a.html 53,282 This information file
2 30-52-e.html 28,163 Tables with numerical data
3 Figure_1.gif 356 Fig. 1: SF Cyclotron Experimental Arrangement
4 Figure_2.gif 356 Fig. 2: FM Cyclotron Experimental Arrangement
5 Figure_3.gif 442 Fig. 3: Measured Angular spectrum from 30 MeV protons on carbon
6 Figure_4.gif 438 Fig. 4: Measured Angular spectrum from 30 MeV protons on iron
7 Figure_5.gif 442 Fig. 5: Measured Angular spectrum from 30 MeV protons on copper
8 Figure_6.gif 438 Fig. 6: Measured Angular spectrum from 30 MeV protons on lead
9 Figure_7.gif 479 Fig. 7: Measured angular distributions of neutrons integrated
from 3-MeV to 30-MeV from 30-MeV protons on four targets
10 Figure_8.gif 442 Fig. 8: Measured Angular spectrum from 52 MeV protons on carbon
11 Figure_9.gif 438 Fig. 9: Measured Angular spectrum from 52 MeV protons on iron
12 Figure_10.gif 444 Fig. 10: Measured Angular spectrum from 52 MeV protons on copper
13 Figure_11.gif 440 Fig. 11: Measured Angular spectrum from 52 MeV protons on lead
14 Figure_12.gif 481 Fig. 12: Measured angular distributions of neutrons integrated
from 5-MeV to 52-MeV from 52-MeV protons on four targets
15 Figure_13.gif 446 Fig. 13: Angular distribution of neutron spectra from 30-MeV protons on carbon
16 Figure_14.gif 442 Fig. 14: Angular distribution of neutron spectra from 30-MeV protons on iron
17 Figure_15.gif 446 Fig. 15: Angular distribution of neutron spectra from 30-MeV protons on copper
18 Figure_16.gif 442 Fig. 16: Angular distribution of neutron spectra from 30-MeV protons on lead
19 Figure_17.gif 479 Fig. 17: Angular distributions of neutrons integrated from 3-MeV to 30-MeV from 30-MeV protons
20 Figure_18.gif 435 Fig. 18: Angular distribution of neutron energy spectra from 52-MeV protons on carbon.
21 Figure_19.gif 431 Fig. 19: Angular distribution of neutron energy spectra from 52-MeV protons on iron.
22 Figure_20.gif 435 Fig. 20: Angular distribution of neutron energy spectra from 52-MeV protons on copper.
23 Figure_21.gif 431 Fig. 21: Angular distribution of neutron energy spectra from 52-MeV protons on lead.
24 Figure_22.gif 481 Fig. 22: Angular distributions of neutrons integrated from 5-MeV to 52-MeV from 52-MeV protons.

File 30-52-e.html contains the following table:

Table 1: Thickness and Density of Targets.
Table 2: Measured Angular spectrum from 30 MeV protons on carbon.
Table 3: Measured Angular spectrum from 30 MeV protons on iron.
Table 4: Measured Angular spectrum from 30 MeV protons on copper.
Table 5: Measured Angular spectrum from 30 MeV protons on lead.
Table 6: Measured angular distributions of neutrons integrated from 3-MeV to 30-MeV from 30-MeV protons on four targets.
Table 7: Measured Angular spectrum from 52 MeV protons on carbon.
Table 8: Measured Angular spectrum from 52 MeV protons on iron.
Table 9: Measured Angular spectrum from 52 MeV protons on copper.
Table 10: Measured Angular spectrum from 52 MeV protons on lead.
Table 11: Measured angular distributions of neutrons integrated from 5-MeV to 52-MeV from 52-MeV protons on four targets.

Figures are included in the GIF format.

SINBAD Benchmark Generation Date: 11/2008
SINBAD Benchmark Last Update: 11/2008