Published March 1962
| Version v1
Book
Study of the kinetics of a research reactor by the probability method
Description
Among the statistical methods used to determine kinetic parameters of critical and near-critical assemblies, the most suitable for the intermediate energy range is the Feynman alpha method, which is based on measurement of the relationship between relative dispersion (n-bar2 - n-bar2)/n-bar=1+φ(t) in the number of counts n for a given interval of time, and the duration of the interval (t). According to the papers presented by a number of American scientists at the 1958 Geneva Conference, their dispersion measurements were carried out by direct recording of the number of pulses in the intervals, and involved subsequently a laborious process of squaring the numerous data obtained. In order to obtain the value of α=(1-kp)/l, Lukov processed data for ∼104 intervals. By the method described in this paper, dispersion values are obtained indirectly by applying the law of distribution for the number of counts, as distinct from Poisson's law. In this way the laborious operations needed to obtain the data can be performed automatically in the process of measurement. Further, a five-channel statistical analyser has been developed and is described in the paper. This device, which is constructed of the simplest elements (triggers), can carry out the operations referred to above simultaneously for five different intervals. Thus, even in the case of a thermal reactor, processed data for ∼3x 105 intervals can generally be accumulated in five minutes, a fact which guarantees a high degree of statistical precision and permits a better utilization of the information obtained. In the intermediate-energy range, data can be processed for more than 106 intervals in the same period of time. The paper gives examples of the application of statistical analysis, and the results of measurements made with a multi-channel statistical analyser. (author)
Abstract (French)
Parmi les diverses methodes statistiques qui permettent de determiner les parametres de cinetique des ensembles critiques et installations analogues, la plus utile dans la region des energies moyennes est la methode de Feynman-α fondee sur la mesure de la dependance de la dispersion relative (n-bar2 - n-bar2)/n-bar=1+φ(t) du nombre de coups n pour un intervalle de temps donne, par rapport a la duree de cet intervalle t. Dans les etudes d'un certain nombre d'auteurs americains qui ont ete presentees a la Conference de Geneve de 1958, la dispersion est mesuree par enregistrement direct du nombre d'impulsions dans les intervalles, suivi d'un depouillement complexe, par l'intermediaire d'un grand nombre d'elevations au carre. Pour obtenir la grandeur α=(1-kp)/l, V. Loukov a depouille les donnees dans ∼104 intervalles. Le present memoire determine la valeur de la dispersion d'une facon indirecte, en appliquant la loi de distribution du nombre de coups - loi qui differe de celle de Poisson - ce qui permet d'effectuer automatiquement, au cours des mesures, les operations les plus complexes, indispensables pour l'obtention de α. De plus, l'analyseur statistique a cinq canaux decrit dans le memoire, qui se compose des elements les plus simples (declencheurs), effectue ces operations simultanement dans cinq intervalles differents. Par consequent, il se produit en 5 minutes, meme pour un reacteur thermique, une accumulation dans ∼3x105 intervalles de donnees completement exploitees, ce qui assure une grande precision statistique grace a une meilleure utilisation des renseignements. Dans la region des energies moyennes, le traitement des donnees exige le meme laps de temps dans plus de 106 intervalles. Le memoire cite des exemples d'application d'une analyse statistique, ainsi que les resultats des mesures effectuees a l'aide d'un analyseur statistique multicanaux. (author)Abstract (Spanish)
Entre los metodos estadisticos utilizados para determinar los parametros cineticos de los conjuntos criticos y cuasi-criticos el que mayor utilidad tiene en el terreno de las energias intermedias es el alfa de Feynman, que se basa en la determinacion de la relacion de dependencia existente entre la dispersion relativa (n-bar2 - n-bar2)/n-bar=1+φ(t), para un numero n de lecturas en un intervalo de tiempo dado t y la duracion de este ultimo. En los trabajos de una serie de autores estadounidenses , presentados a la Conferencia de Ginebra del ano 1958, la determinacion de la dispersion se efectuaba por registro directo del numero de impulsos en los intervalos correspondientes, seguida por un laborioso calculo de cuadrados. Para obtener el valor de α=(1-kp)/l, V. Lukov trabajo con datos de hasta 104 intervalos, aproximadamente. En cambio, en el presente trabajo los valores de dispersion se determinan indirecta- mente aplicando la ley de distribucion del numero de impulsos que, a diferencia de la ley de Poisson, permite efectuar automaticamente , durante el proceso de medicion, las laboriosas operaciones necesarias para obtener el valor de alfa. Ademas, un ana- lizador estadistico de cinco canales ideado especialmente y descrito en la memoria, que se construyo con los elementos mas sencillos (disparadores), efectua dichas opera- ciones simultaneament e para cinco intervalos diferentes. Gracias a este metodo, aun en el caso de los reactores de neutrones termicos, es posible obtener en cinco minutos datos elaborados que correspondan a 3x105 intervalos, aproximadamente, lo que permite alcanzar una elevada exactitud estadistica y aprovechar mejor la informacion asi obtenida. En el caso de las energias intermedias, es posible elaborar en el tiempo senalado los datos correspondiente s a mas de 106 intervalos. El autor presenta ejemplos de la aplicacion del analisis estadistico y resultados de las determinaciones efectuadas por medio del analizador estadistico multicanal. (author)Abstract (Russian)
Sredi primenyaemykh statisticheskikh metodov opredeleniya parametrov kinetiki kriticheskikh i blizkikh k nim sborok naibol'shej prigodnost'yu v promezhutochnoj oblasti ehnergij obladaet metod Fejnmana-alfa, osnovannyj na izmerenii zavisimosti otnositel'noj dispersii (n-bar2 - n-bar2)/n-bar=1+φ(t) v chisle otschetov l za nekotoryj interval vremeni ot dlitel'nosti ehtogo intervala t. V rabotakh ryada amerikanskikh avtorov, predstavlenny kh na Zhenevskuyu konferentsiyu 1958 goda, izmereniya dispersii vypolnyayutsya putem neposredstvenno j zapisi chisla im- pul'sov v intervalakh s posleduyushchej trudoemkoj obrabotkoj posredstvom mnogochislennykh vozvedenij v kvadrat. Dlya polucheniya velichiny α=(1-kp)/l, Lukov obrabatyval dannye po ∼104 intervalam. V nastoyashchej rabote znachenie dispersii opredelyaetsya kosvenno na osnove ispol'zovaniya zakona raspredeleniya dlya chisla otschetov, otlichnogo ot zakona Puassona, chto pozvolyaet naibolee trudoemkie operatsii, neobkhodimye dlya polucheniya os, vypolnyat' avtomaticheski v protsesse izmereniya. Bolee togo, razrabotannyj i opisannyj v doklade 5-kanal'nyj statisticheskij analizator, postroennyj iz prostejshikh ehlementov (triggerov), vypolnyaet ehti operatsii odnovremenno dlya 5 razlichnykh intervalov. V rezul'tate dazhe dlya teplo- vogo reaktora za 5 minut nakaplivayutsya v osnovnom obrabotannye dannye po ∼3x105 intervalam, chto obespechivaet vysokuyu statisticheskuyu tochnost' za schet luchshego ispol'zovaniya informatsii. V promezhutochnoj oblasti ehnergij za ehto zhe vremya obrabatyvayuts ya dannye bolee chem za 106 intervalov. V doklade privodyatsya primery primeneniya statisticheskog o analiza i rezul'taty izmerenij, vypolnennykh s pomoshch'yu mnogokanal'nog o statisticheskog o analizatora. (author)Additional details
Additional titles
- Original title (Russian)
- Етуде де ла cинетиqуе дьун реаcтеур пхысиqуе пар ла метходе де пробабилите; Изучение кинетики физического реактора вероятностным методом; Естудио де ла cинетиcа де ун реаcтор де инвестигаcион медианте ел cалcуло де пробабилидадес
Publishing Information
- Publisher
- Globus, Druck- und Verlagsanstalt, Vienna
- Imprint Place
- Vienna (International Atomic Energy Agency (IAEA))
- Imprint Title
- Physics of Fast and Intermediate Reactors. V. III. Proceedings of the Seminar on the Physics of Fast and Intermediate Reactors. V. III
- Imprint Pagination
- 633 p.
- Series
- Proceedings Series
- Journal Page Range
- p. 33-40
- ISSN
- 0074-1884
Conference
- Title
- Seminar on Physics of Fast and Intermediate Reactors
- Dates
- 3-11 Aug 1961
- Place
- Vienna (Austria)
INIS
- Country of Publication
- International Atomic Energy Agency (IAEA)
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 44050772
- Subject category
- S22: GENERAL STUDIES OF NUCLEAR REACTORS; S73: NUCLEAR PHYSICS AND RADIATION PHYSICS;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- DISPERSIONS; ENERGY RANGE; PROBABILITY; REACTOR KINETICS; RESEARCH REACTORS; THERMAL REACTORS; ZERO POWER REACTORS
- Descriptors DEC
- EXPERIMENTAL REACTORS; KINETICS; REACTORS; RESEARCH AND TEST REACTORS
Optional Information
- Notes
- 9 refs, 4 figs Imprint:In three volumes
- Secondary number(s)
- IAEA-SM--18/87