1. Name of Experiment:
 ------------------
 Winfrith Water Benchmark Experiment (ASPIS)

2. Purpose and Phenomena Tested:
 ----------------------------
 Determination of the fast neutron spectra above 1 MeV and detector
 reaction rates up to 50 cm in water.

3. Description of the Source and Experimental Configuration:
 --------------------------------------------------------
 Winfrith Water Benchmark Experiment comprised a central air-filled
 measurement tube surrounded by up to 8 symmetrically located Cf-252
 sources. The whole arrangement was contained within a water tank. The
 sources were movable along the support arms by units of 50.8 mm in order
 to alter the source-detector separation distance.

4. Measurement System and Uncertainties:
 ------------------------------------
 The detectors used were:

 Detector Diameter Thickness Mass Systematic Statistical
 (mm) (mm) (g) Error (%) Error (%)
 ---------------------------------------------------------------------
 S-32(n,p)P-32 28 28 32.07+-1.6 6

 NE213 Spectr. vol.= 3ml 5 1 - 10
 ---------------------------------------------------------------------


5. Description of Results and Analysis:
 -----------------------------------
 The measured data comprises spectra unfolded by RADAK [4] from the
 pulse-hight spectra of a NE213 organic liquid scintillator and the
 S-32(n,p)P-32 reaction rates.
 Spectrometer measurements were performed, on axis only, at 10.16, 15.24,
 20.32, 25.4, 30.48, 35.56 and 50.8 cm source/detector separation. Sulphur
 measurements were on axis and displaced vertically +-15 cm and +-30 cm at
 source/detector separations of 10.16, 15.24, 25.40, 30.45 and 35.56 cm.

 Calculations by Sn code DOT and M/C code MCBEND, TRIPOLI and direct
 integration code PALLAS-2D were reported in the literature [2], [3], [5],
 [6], [7] and [8]. P-5 approximated calculation was found to improve the
 accuracy of the calculation as compared with that by P-3 approximation.


6. Special Features:
 ----------------

 None

7. Author/Organizer
 ----------------
 Experiment and analysis:
 M.D. Carter, A. Packwood:
 AEA Technology
 WINFRITH, Dorchester
 Dorset DT2 8DH, UK

 Compiler of data for Sinbad:
 I. Kodeli
 OECD/NEA, 12 bd des Iles, 92130 Issy les Moulineaux, France

 Reviewer of compiled data:
 S. Zheng
 CEA-Saclay/DMT/SERMA/LEPP
 91191 Gif-sur-Yvette CEDEX, France


8. Availability:
 ------------

 Unrestricted

9. References:
 ----------
 [1] M.D. Carter and A. Packwood,
 "The Winfrith Water Benchmark Experiment", NEARCRP-A-628 (1984)
 [2] A.K. McCracken, A.E.E. Winfrith,
 "An Analysis of the Winfrith Water Benchmark Experiment Using the
 MCBEND Monte Carlo Code",
 NEACRP Specialists' Meeting on Shielding Benchmarks, Paris (1986)
 [3] P. C. Miller, A.E.E. Winfrith, E. Sartori,
 "An Analysis of the Winfrith Water Benchmark Experiment Using the
 VITAMIN-J/175 Multigroup Library of the JEF-1 Cross-Section File",
 NEACRP Specialists' Meeting on Shielding Benchmarks, Paris (1986)
 [4] M.J. Grimstone,
 The RADAK User's Manual, AEEW-M1455 (1976)
 [5] G.A. Wright et al.,
 "Monte Carlo Sensitivity Analysis of the Winfrith Benchmark
 Experiments using JEF-1 Cross-sections",
 Proc. 7th Int. Conf. Radiation Shielding, Bournemouth, Sept. 1988,
 2, pp. 725-733.
 [6] H.F. Locke, G.A. Wright,
 "Benchmark testing of JEF2.2 Data for Shielding Applications: Analysis
 of the Winfrith Water Benchmark Experiment", AEA-RS-1232 (1993)
 [7] J. C. Nimal, S. H. Zheng, Rapport DMT 94/159, CEA-Saclay
 [8] N. Sasamoto, H. Narita, A. Tsubosaka, K. Sakurai, K. Ueki,
 "An Analysis of the Winfrith Water Benchmark Experiment with DOT-DDX",
 private communication (1987)
 [9] G. A. Wright, A. Avery, M. J. Grimstone, H. F. Locke, S. Newbon,
 Benchmarking of the JEFF2.2 Data Library for Shielding Applications,
 Proceedings, 8th International Conference on Radiation Shielding,
 April 24-28, 1994, Arlington, Texas, U.S.A., vol.2, p.816.


10. Data and Format:
 ---------------

 Filename Size[bytes] Content
 ---------------- ----------- -------------
 1 ah2o-abs.htm 8.218 This information file
 2 ah2o-exp.htm 20.414 Description of Experiment
 3 ASP-H2O.INP 25.134 Input data of TRIPOLI calculation for 25.4 cm
 4 H2O-1V.TIF 17.036 Figure 1: Schematic of the Water Benchmark Experiment 
   (high quality)
 5 H2O-2V.TIF 15.456 Figure 2: Detail of the Water Benchmark Experiment 
   (high quality)
 6 H2O-3V.TIF 52.874 Figure 3: Model of the Source Capsule (high quality)
 7 H2O-4V.TIF 25.824 Figure 4: NPL Anisotropy Measurement Cf-252 Source 
   (high quality)
 8 H2O-1V.gif 13.269 Figure 1: Schematic of the Water Benchmark Experiment 
   (preview)
 9 H2O-2V.gif 10.941 Figure 2: Detail of the Water Benchmark Experiment (preview)
10 H2O-3V.gif 16.195 Figure 3: Model of the Source Capsule (preview)
11 H2O-4V.gif 16.519 Figure 4: NPL Anisotropy Measurement Cf-252 Source (preview)
12 H20_1.pdf 593.771 Reference
13 H20_2.pdf 255.310 Reference
14 H20_3.pdf 465.952 Reference
15 H20_5.pdf 466.125 Reference
16 H20_6.pdf 1.235.986 Reference
17 H20_7.pdf 1.733.460 Reference
18 H20_8.pdf 388.905 Reference
19 jef-476.pdf 578.980 Reference

 Figures are included in TIFF and GIF (preview) file format.

 TABLES
 1. Composition of the Source Capsule
 2. Experimental Source Arrangements
 3. Neutron Spectrum at 10.16 cm
 4. Neutron Spectrum at 15.24 cm
 5. Neutron Spectrum at 20.32 cm
 6. Neutron Spectrum at 25.4 cm
 7. Neutron Spectrum at 30.48 cm
 8. Neutron Spectrum at 35.56 cm
 9. Neutron Spectrum at 50.8 cm
 10. S-32(n,p)P-32 Measured Reaction Rates