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FNG/TUD TUNGSTEN EXPERIMENT
1. Name of experiment:
-------------------
TUD/FNG measurement of neutron and photon flux spectra in the FNG tungsten
assembly (2002).
2. Purpose and phenomena tested:
-----------------------------
Transport data benchmark by determination of spectral neutron flux and
spectral photon flux at four positions in a thick block of W irradiated
with 14 MeV neutrons
3. Description of source and experimental configuration:
-----------------------------------------------------
The Frascati Neutron Generator [1] was used as 14 MeV D-T neutron
source. The angular dependence of the source intensity is presented in
Fig. 1. The angular dependence of the source energy distribution is
given in Fig. 2. Note that these figures were obtained using the obsolete
D-T source subroutine (source.for) and may vary slightly from those of
the new recommended subroutine (DT_MCNP5.TXT for MCNP5, source.F and
srcdx.F for MCNPX).
The geometry of the assembly is shown in Fig. 3. The angle between the
deuteron beam of the neutron generator and an axis crossing neutron
source and centre of the detector was 0 degrees. The dimensions of the
W alloy block were 47 cm * 47 cm * 49 cm of length (z-axis). The tritium
target of the neutron source was located at z = -5.3 cm.
The W alloy of the central part had a density of 18.1 g/cm3 and an elemental
composition of 95 wt-% of W, 1.6 wt-% of Fe and 3.4 wt-% of Ni.
Neutron and photon flux spectra were measured on the central axis of
the assembly in four positions (P1,...,P4) at z = 5, 15, 25 and 35 cm.
4. Measurement system:
----------------------
Neutron and photon pulse-height spectra were measured simultaneously
using an NE 213 scintillation spectrometer. The dimensions of the
cylindrical active volume of the detector were 3.8 cm in both height
and diameter. Its material had a mass density of 0.874 g/cm3 and an
elemental composition of 54.8 at-% H and 45.2 at-% C.
The scintillator was coupled to a photomultiplier by means of a 50 cm
long light guide. When the detector was located at one of the
positions (P 2 in Fig. 3), the other ones were filled with rods of W
alloy.
5. Description of results and analysis:
---------------------------------------
Data evaluation:
The DIFBAS code developed at PTB Braunschweig [2,3] was employed for
unfolding the measured pulse-height distributions in order to generate
the neutron and photon flux spectra. They were obtained as absolute
fluxes, as the response matrices have been determined on an absolute
scale by detailed simulations of experimental distributions from mono-
energetic neutron and photon sources with Monte Carlo codes.
Calculations:
A computational analysis was performed with the Monte Carlo code MCNP-
4C [4] using a full 3D model of the assembly, the neutron generator and
the experimental hall. Nuclear data were taken from the FENDL/MC-2.0
data library [5]. The spectra were calculated as average flux in the
scintillator volume by means of the track length estimator of MCNP.
Results are shown in Figs. 4, 5, 6, 7, 8, 9, 10 and 11. More details
are given in Ref. [6].
For the activation foil and TLD measurements on the same Tungsten block see
FNG Tungsten Experiment.
6. Quality assessment:
------------
The TUD/FNG TUNGSTEN experiment could be ranked as benchmark quality
experiment, provided that supplementary experimental information is
available on:
– realistic and complete estimation of neutron and gamma flux point–wise
uncertainties,
- availability of the original pulse-height distributions measured by
spectrometers and the detector geometry would be useful for those who
wish to carry out their own spectra unfolding,
- some inconsistencies observed with the FNG-W benchmark results should
be explained and resolved.
For detailed evaluation see Ref. [8].
7. Authors/Organizer:
------------------
Experiment and analysis:
K. Seidel, H. Freiesleben, C. Negoita, S. Unholzer
Technische Universitaet Dresden
Institut fuer Kern- und Teilchenphysik
D-01062 Dresden
Germany
U. Fischer, D. Leichtle
Forschungszentrum Karlsruhe
Institut fuer Reaktorsicherheit
D-76021 Karlsruhe
Germany
M. Angelone, P. Batistoni, M. Pillon
Associazione ENEA-EURATOM
Settore Fusione - Divisione Neutronica
Via E. Fermi 27
I-00044 Frascati (Rome)
Italy
Compiler of data for Sinbad:
K. Seidel
Technische Universitaet Dresden
Institut fuer Kern- und Teilchenphysik
D-01062 Dresden, Germany
Quality assessment:
A. Milocco, Institut Jožef Stefan, Jamova 39, Ljubljana, Slovenia
Reviewer of compiled data:
I. Kodeli
OECD/NEA, 12 bd des Iles, 92130 Issy les Moulineaux, France
8. Availability:
-------------
Unrestricted
9. References:
-----------
[1] M. Angelone, M. Pillon, P. Batistoni, M. Martini, M. Martone, V.
Rado, "Absolute experimental and numerical calibration of the 14
MeV neutron source at the Frascati Neutron Generator", Rev. Sci.
Instr. 67(1996)2189.
[2] M. Tichy, "The DIFBAS Program - Description and User's Guide",
Report PTB-7.2- 193-1, Braunschweig 1993.
[3] S. Guldbakke, H. Klein, A. Meister, J. Pulpan, U. Scheler, M.
Tichy, S. Unholzer, "Response Matrices of NE213 Scintillation
Detectors for Neutrons", Reactor Dosimetry ASTM STP 1228, Ed. H.
Farrar et al., American Society for Testing Materials,
Philadelphia, 1995, p. 310.
[4] J. F. Briesmeister (Ed.), "MCNP - A general Monte Carlo n-particle
transport code", version 4C, Report LA-13709, Los Alamos National
Laboratory, 2000.
[5] H. Wienke, M. Herman, "FENDL/MG-2.0 and FENDL/MC-2.0 - The
processed cross section libraries for neutron and photon transport
calculations", Report IAEA-NDS-128, Vienna, 1998.
[6] H. Freiesleben, C. Negoita, K. Seidel, S. Unholzer, U. Fischer, D.
Leichtle, M. Angelone, P. Batistoni, M. Pillon, "Measurement and
analysis of neutron and gamma-ray flux spectra in Tungsten",
Report TUD-IKTP/01-03, Dresden, EFFDOC-857 (2003)
[7] U. Fischer et al., Monte Carlo Transport and Sensitivity Analyses
for the TUD Neutron Transport Benchmark Experiment on Tungsten,
EFFDOC-860 (2002)
[8] A. Milocco, The Quality Assessment of the FNG/TUD Benchmark Experiments,
IJS-DP-10216, April 2009
[9] A. Milocco, A. Trkov, MCNPX/MCNP5 Routine for Simulating D–T Neutron
Source in Ti-T Targets, IJS-DP-9988, July 2008
10. Data and Format:
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DETAILED FILE DESCRIPTIONS
--------------------------
No. File name Size (kB) Content
------------- --------- ---------------
1 tudw-a.htm 11,751 This abstract
2 tudw-e.htm 42,286 Description of experiment
3 tudw-c.htm 15,189 Description of transport calculations
4 FNG-TUD.pdf 221,831 Document describing the quality assessment of the
FNG and TUD benchmarks
5 D-T.pdf 493,108 Document describing the D–T source routine for MCNPX(5)
6 DT_MCNP5.TXT 51,672 Patch with MCNP5 source subroutines for the calculation
of 14-MeV D-T source (new release)
7 source.F 29,688 source.F subroutine for MCNPX-2.6f to calculate 14-MeV
D-T source (new release)
8 srcdx.F 12,709 srcdx.F subroutine for MCNPX-2.6f containing also
subroutines for numerics to calculate 14-MeV D-T
source (new revised version)
9 source.for 39,959 FNG D–T source routine for MCNP4C (obsolete)
10 mcnp.inp 36,252 3-D model for MCNP-4C code
11 fig1.jpg 27,072 Fig. 1: Angular dependence of the neutron source
12 fig2.jpg 50,616 Fig. 2: Neutron source energy/angular distribution
13 fig3.jpg 24,793 Fig. 3: Geometry of the assembly
14 fig4.jpg 31,016 Fig. 4: Neutron spectra at position P-1
15 fig5.jpg 31,869 Fig. 5: Neutron spectra at position P-2
16 fig6.jpg 31,057 Fig. 6: Neutron spectra at position P-3
17 fig7.jpg 32,138 Fig. 7: Neutron spectra at position P-4
18 fig8.jpg 32,047 Fig. 8: Gamma-ray spectra at position P-1
19 fig9.jpg 32,657 Fig. 9: Gamma-ray spectra at position P-2
20 fig10.jpg 33,364 Fig. 10: Gamma-ray spectra at position P-3
21 fig11.jpg 32,926 Fig. 11: Gamma-ray spectra at position P-4
22 eff-857.pdf 290,424 Reference [6] EFFDOC-857
23 eff-860.pdf 1,067,715 Reference [7] EFFDOC-860
Files tudw-e.htm and tudw-c.htm contain the following tables:
Tab. 1: Angular dependence of the source
Tab. 2: Angular dependence of the source energy distribution
Tab. 3: Spectral neutron fluences for P1...P4, experiment
Tab. 4: Uncertainties of the measured neutron fluences
Tab. 5: Spectral photon fluences for P1...P4, experiment
Tab. 6: Uncertainties of the measured photon fluences
Tab. 7: Spectral neutron fluences for P1...P4, calculation
Tab. 8: Spectral photon fluences for P1...P4, calculation
The figures describing the geometry of the experiment and the
spectral fluences are included as PostScript and jpg files.
SINBAD Benchmark Generation Date: 4/2004
SINBAD Benchmark Last Update: 2/2010