Abstract
The slowing down of neutrons in thin hydrogeneous moderators of different thickness and finite lateral dimensions is studied using two experimental methods, a) the direct method of measuring the time distribution of neutrons slowed down to a specified energy and leaving the moderator, b) an indirect method which consists of determining the influence of such a moderator on the resonance width of a known neutron resonance at low energy measured by the time-of-flight neutron spectrometer. The experimental results are compared with Monte Carlo calculations and with theoretical expressions derived elsewhere. Fairly good agreement is obtained between experiment and the Monte Carlo calculations. The theoretical predictions are seen to be of limited range of validity only and especially a great difference between the theoretical and experimental time variance of the slowing-down time is observed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Marshak R. E.: Rev. Mod. Physics19 (1947), 3.
Claesson A.: AE-71, Aktiebolaget Atomenergi, Stockholm 1962.
Claesson A.: Arkiv för Fysik33 (1967), 443.
Claesson A.: AE-129, Aktiebolaget Atomenergi, Stockholm 1963.
Beckurts K. H.: Neutron Physics. Springer-Verlag, Berlin 1964.
Michaudon A.: Reactor Science and Technology17 (1963), 165.
Michaudon A.: Proc. Symp. on Neutron Time-of-Flight Methods, Saclay, 24–27 July 1961.
Crouch M. F.: Nucl. Sci. Eng.2 (1957), 631.
Engelmann P.: Nukleonik1 (1958), Heft 4.
Möller E., Sjöstrand N. G.: Arkiv för Fysik27 (1964), 501.
Uttley C. A., Jones R. H.: AERE-R 3281, Harwell 1960.
Solal M.: Rep. No. 196, Service de calcul electronique, CEN Saclay 1965.
Asghaw M. et al.: Nuclear Physics85 (1966), 305.
Fabián V.: Fundamental Statistical Methods (in Czech). Academia, Praha 1963.
Janko J.: Statistical Tables (in Czech). Academia, Praha 1958.
Reisenauer R.: Methods of Mathematical Statistics and their Applications (in Czech). SNTL — Práce, Praha 1965.
šor J. B.: Statističeskie metody analiza i kontrola kačestva i nadĚŽnosti (translation into Czech). SNTL, Praha 1965.
Kendall M. G., Stuart A.: The Advanced Theory of Statistics, Vol. I., London. Russian translation, Moscow 1966.
Hald A.: Statistical Theory with Engineering Application. John Wiley & Sons Inc., New York-London 1957.
King J. D.: Saskatchevan Accelerator Laboratory. Internal report No. 6 unpublished.
Drawbaugh D. W. et al.: Conf. on Neutron Cross Section Technology. March 22–24, Washington 1966.
Girard J., Ribon P.: Rep. DRP/SMNF No. 616/68. CEN Saclay 1968.
Author information
Authors and Affiliations
Additional information
The author would like to thank Dr. R. Joly and Dr. A. Michaudon for their suggestion that this work be performed in CEN Saclay as well as for their support and interest during the measurements in Saclay. He would also like to acknowledge the help of Dr. P. Ribon, Mr. Paya, Mr. Derrien, his wife Jarmila and Mr. Girard and the accelerator group in CEN Cadarache under the direction of Mr. Leroy during the measurements on the Van de Graaff accelerator. He is very obliged to the International Atomic Energy Agency in Vienna for having offered a stipend in France without which the present work could not have been done.
Rights and permissions
About this article
Cite this article
Bayer, R. The slowing down of fast neutrons in thin hydrogeneous moderators. Czech J Phys 19, 1103–1126 (1969). https://doi.org/10.1007/BF01691760
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01691760