Published 1964 | Version v1
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Measurements of spectral indices in homogeneous multiplying media

  • 1. Commissariat a l'Energie Atomique, Saclay (France). Centre d'Etudes Nucleaires

Description

Methods for computation of spectra in light water are developed at Saclay and it is interesting to carry out at the same time experimental studies of simple media such as solutions of fissionable salts which allow quite direct comparisons with computed values. The spectral indices measurements were made with two small fission chambers, one containing deposited plutonium, the other deposited uranium 235. Their response, when neutron spectrum is modified, allows to study the epithermal part of the flux. The media studied with these chambers are fissionable solutions (of plutonium or 90 per cent enriched uranium) which were made critical in bare cylindrical geometry in the Alecto reactor. If the ratio of the chambers is normalized to unity in a Maxwell spectrum, then the noted variation of the ratio of the counts Pu chamber/ U235 chamber reaches 1,4 in the range of the studied concentrations. (authors)

Availability note (English)

Available from INIS in electronic form

Abstract (French)

Des calculs de spectres dans l'eau legere sont mis au point a Saclay et il est interessant de mener parallelement des etudes experimentale sur des milieux simples tels que des solutions de sels fissiles, qui permettent des comparaisons tres directes avec les valeurs calculees. On a choisi d'effectuer des mesures d' 'indices de spectres' a l'aide de de deux petites chambres a fission contenant des depots, l'une de plutonium, l'autre d'uranium 235. Leur reponse lorsque le spectre des neutrons est modifie permet d'etudier la partie epithermique du flux. Les milieux etudies a l'aide de ces chambres sont des solutions fissiles (plutonium ou uranium enrichi a 90 pour cent) rendus critiques, en geometrie cylindrique nue, dans le reacteur Alecto. Si le rapport des chambres est normalise a un dans un spectre de Maxwell, la variation constatee du rapport des comptages chambre Pu/ chambre U235 atteint, dans les gammes de concentrations etudiees, 1,4. (auteurs)

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Additional details

Additional titles

Original title (French)
Mesures d'indices de spectre dans les milieux multiplicateurs homogenes

Publishing Information

Imprint Pagination
65 p.
Report number
CEA-R--2455

Optional Information

Notes
15 refs.