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The Prompt Gamma-Ray, Prompt Electron and Prompt X-Ray Spectra Associated with Fission Fragments of Specific Mass; Spectres de Rayons Gamma Instantanes, d'Electrons Instantanes et de Rayons X Instantanes Associes a des Fragments de Fission de Masse Donnee; 041c 0413 041d 041e 0414 ; Espectros de Rayos Gamma. Electrones y Rayos X Inmediatos, Vinculados a Fragmentos de Fision de Masa Determinada

Conference:

Abstract

Well-defined prompt gamma-rays, prompt-conversion elections and prompt K-X-rays have been observed in coincidence with moving fission fragments of Cf{sup 252}. In a few cases, the masses and charges of the nuclei emitting the gamma-rays and conversion electrons have been identified. The gamma-ray, prompt-electron and prompt X-ray energies as well as the two fission fragments energies were measured with high-resolution solid-state detectors. The masses of the fragments were deduced from their energies, and the nuclear charges were determined by measuring the K-X - ray energies associated with different masses. The magnitude and sign of the Doppler shift in gamma-ray energy allowed assignment of the gamma-ray lines to single members of fragment pairs. The Doppler shift also provides an independent measure of the fragment velocity and hence the fragment mass after neutron emission. The results of the X-ray measurements are consistent with the view that the majority of the prompt X-rays emitted during the spontaneous fission of Cf{sup 252} are the result of internal conversion during the de-excitation of low-energy collective states of the primary fission fragments. Apart from the specific results discussed above, the most important consequence of these experiments has been the demonstration that it is possible to study the  More>>
Authors:
Bowman, H. R.; Thompson, S. G.; Watson, R. L.; Kapoor, S. S.; Rasmussen, J. O. [1] 
  1. Lawrence Radiation Laboratory, University of California, Berkeley, CA (United States)
Publication Date:
Jul 15, 1965
Product Type:
Conference
Report Number:
IAEA-SM-60/53
Resource Relation:
Conference: Symposium on Physics and Chemistry of Fission, Salzburg (Austria), 22-26 Mar 1965; Other Information: 12 refs., 13 figs., 1 tab.; Related Information: In: Physics and Chemistry of Fission. Vol. II. Proceedings of the Symposium on Physics and Chemistry of Fission| 485 p.
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ATOMIC NUMBER; CALIFORNIUM 252; DE-EXCITATION; DOPPLER EFFECT; FISSION FRAGMENTS; GAMMA RADIATION; INTERNAL CONVERSION; MASS; NEUTRON EMISSION; PROMPT ELECTRONS; SPONTANEOUS FISSION; VELOCITY; X RADIATION; X-RAY SPECTRA
OSTI ID:
22184515
Research Organizations:
International Atomic Energy Agency, Vienna (Austria)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA13M3191008523
Submitting Site:
INIS
Size:
page(s) 125-141
Announcement Date:
Jan 30, 2014

Conference:

Citation Formats

Bowman, H. R., Thompson, S. G., Watson, R. L., Kapoor, S. S., and Rasmussen, J. O. The Prompt Gamma-Ray, Prompt Electron and Prompt X-Ray Spectra Associated with Fission Fragments of Specific Mass; Spectres de Rayons Gamma Instantanes, d'Electrons Instantanes et de Rayons X Instantanes Associes a des Fragments de Fission de Masse Donnee; 041c 0413 041d 041e 0414 ; Espectros de Rayos Gamma. Electrones y Rayos X Inmediatos, Vinculados a Fragmentos de Fision de Masa Determinada. IAEA: N. p., 1965. Web.
Bowman, H. R., Thompson, S. G., Watson, R. L., Kapoor, S. S., & Rasmussen, J. O. The Prompt Gamma-Ray, Prompt Electron and Prompt X-Ray Spectra Associated with Fission Fragments of Specific Mass; Spectres de Rayons Gamma Instantanes, d'Electrons Instantanes et de Rayons X Instantanes Associes a des Fragments de Fission de Masse Donnee; 041c 0413 041d 041e 0414 ; Espectros de Rayos Gamma. Electrones y Rayos X Inmediatos, Vinculados a Fragmentos de Fision de Masa Determinada. IAEA.
Bowman, H. R., Thompson, S. G., Watson, R. L., Kapoor, S. S., and Rasmussen, J. O. 1965. "The Prompt Gamma-Ray, Prompt Electron and Prompt X-Ray Spectra Associated with Fission Fragments of Specific Mass; Spectres de Rayons Gamma Instantanes, d'Electrons Instantanes et de Rayons X Instantanes Associes a des Fragments de Fission de Masse Donnee; 041c 0413 041d 041e 0414 ; Espectros de Rayos Gamma. Electrones y Rayos X Inmediatos, Vinculados a Fragmentos de Fision de Masa Determinada." IAEA.
@misc{etde_22184515,
title = {The Prompt Gamma-Ray, Prompt Electron and Prompt X-Ray Spectra Associated with Fission Fragments of Specific Mass; Spectres de Rayons Gamma Instantanes, d'Electrons Instantanes et de Rayons X Instantanes Associes a des Fragments de Fission de Masse Donnee; 041c 0413 041d 041e 0414 ; Espectros de Rayos Gamma. Electrones y Rayos X Inmediatos, Vinculados a Fragmentos de Fision de Masa Determinada}
author = {Bowman, H. R., Thompson, S. G., Watson, R. L., Kapoor, S. S., and Rasmussen, J. O.}
abstractNote = {Well-defined prompt gamma-rays, prompt-conversion elections and prompt K-X-rays have been observed in coincidence with moving fission fragments of Cf{sup 252}. In a few cases, the masses and charges of the nuclei emitting the gamma-rays and conversion electrons have been identified. The gamma-ray, prompt-electron and prompt X-ray energies as well as the two fission fragments energies were measured with high-resolution solid-state detectors. The masses of the fragments were deduced from their energies, and the nuclear charges were determined by measuring the K-X - ray energies associated with different masses. The magnitude and sign of the Doppler shift in gamma-ray energy allowed assignment of the gamma-ray lines to single members of fragment pairs. The Doppler shift also provides an independent measure of the fragment velocity and hence the fragment mass after neutron emission. The results of the X-ray measurements are consistent with the view that the majority of the prompt X-rays emitted during the spontaneous fission of Cf{sup 252} are the result of internal conversion during the de-excitation of low-energy collective states of the primary fission fragments. Apart from the specific results discussed above, the most important consequence of these experiments has been the demonstration that it is possible to study the properties of individual fission fragments, as identified by their characteristic radiations, rather than studying the properties of an average fission fragment with an average mass and charge. The consequences of this advance in the technique of studying fission fragments ate being explored. (author) [French] Des rayons gamma instantanes, des electrons de conversions instantanes et des rayons X K instantanes bien definis ont ete observes en coincidences avec des fragments de fission de {sup 252}Cf en mouvement. Dans un petit nombre de cas' Les masses, et charges des noyaux emettant les rayons gamma et les electrons de conversion ont ete identifiees. Les energies des rayons gamma, des electrons instantanes et des rayons X instantanes ainsi que les energies des deux fragments de fission ont ete mesurees au moyen de detecteurs a semi-conducteurs a fort pouvoir de resolution. Les masses des fragments ont ete obtenues a partir de leurs energies, et les charges des noyaux ont ete calculees par mesure des energies des rayons X K associees a differentes masses. La grandeur et le signe du deplacement Doppler dans l'energie des rayons gamma ont permis d'atuibuer les raies gamma a des membres isoles de paires de fragments. Le deplacement Doppler permet aussi de determiner independamment la vitesse du fragment et, partant, la masse du fragment apres l'emission de neutrons. Les resultats des mesures des rayons X confirment l'impression que la majorite des rayons X instantanes emis au cours de la fission spontanee de {sup 252}Cf sont dus a une conversion interne pendant la desexcitation d'etats collectifs de faible energie des fragments de fission primaires. En dehors des resultats particuliers decrits ci-dessus, les auteurs estiment que la consequence la plus importante de leurs recherches a ete de demontrer la possibilite d'etudier les proprietes des differents fragments de fission, identifies par leur rayonnement propre - au lieu d'etudier les proprietes d'un fragment de fission moyen, de masse et de charge moyennes. Les auteurs etudient les consequences de ce perfectionnement de la methode utilisee pour etudier les fragments de fission. (author) [Spanish] En coincidencia con fragmentos en movimiento provenientes de la fision del {sup 252}Cf, los autores observaron rayos gamma, electrones de conversion y rayos X-K inmediatos. En algunos casos, pudieron identificar las masas y Las cargas de los nucleos que emiten los rayos gamma y los electrones de conversion. Las energias de los rayos gamma, de los electrones y de los rayos X inmediatos, asi como tambien las energias de los dos fragmentos de fision, se midieron con detectores de semiconductores, de elevado poder de resolucion. Las masas de los fragmentos se dedujeron de sus respectivas energias y las cargas nucleares se determinaron midiendo las energias de los rayos X-K vinculadas a las distintas masas. La magnitud y el signo del desplazamiento de Doppler permitio asignar les lineas espectrales de ios rayos gamma, a cada uno de los componentes de cada par de fragmentos. El desplazamiento de Doppler permite tambien medir independientemente la velocidad de los fragmentos y, por consiguiente, la masa de estos despues de la emision de un neutron. Los resultados de las mediciones realizadas sobre los rayos X concuerdan con la hipotesis de que la mayoria de los rayos X inmediatos emitidos durante la fision espontanea del {sup 252}Cf, son resultado de la conversion interna en los fragmentos de la fision primaria,, durante la desexcitacion de estados colectivos de baja energia. Ademas de los resultados concretos examinados en U memoiia, la consecuencia mas importante de los experimentos descritos es la demostracion de que es posible estudiar por separado las propiedades de cada fragmento de fision, identificado por sus radiaciones caracteristicas (en lugar de estudiar las propiedades de un fragmento de fision medio, con masa y carga tambien medias). Se estudian actualmente las consecuencias de este adelanto logrado en la tecnica de estudio de los fragmentos de fision. (author) [Russian] Nabljudalis' horosho opredelennye mgnovennye gamma-kvanty, mgnovennye konversionnye jelektrony i rentgenovskoe K-izluchenie v sovpadenii s dvizhushhimisja oskolkami delenija kalifornija-252. V neskol'kih sluchajah byli ustanovleny massy i zarjady jader, ispuskajushhih gamma-kvanty i konversionnye jelektrony. Jenergii gamma-kvantov, mgnovennyh jelektronov i mgnovennyh rentgenovskih luchej, a takzhe jenergii dvuh oskolkov delenija byli izmereny s pomoshh'ju tverdogo schetchika s vysokoj razreshajushhej sposobnost'ju. Massy oskolkov byli vyvedeny na osnove ih jenergij, a jadernye zarjady byli opredeleny putem izmerenija jenergij rentgenovskogo K-izluchenija, svjazannyh s razlichnymi massami. Velichina i otmetka Dopplerovskogo smeshenija v jenergii gamma-kvanta pozvolili prichislit' linii gamma-kvantov k otdel'nym chlenam oskolochnyh par. Dopplerovskoe smeshhenie obespechivaet takzhe nezavisimoe izmerenie skorosti oskolka i, sledovatel'no, massy oskolka posle ispuskanija nejtronov. Rezul'taty izmerenij rentgenovskih luchej soglasujutsja s mneniem, chto bol'shinstvo mgnovennyh rentgenovskih luchej, izluchaemyh vo vremja spontannogo delenija kalifornija-252, javljaetsja rezul'tatom vnutrennej konversii v hode vysvechivanija sovokupnyh sostojanij nizkoj jenergii pervichnyh oskolkov delenija . Avtory polagajut, chto pomimo obsuzhdennyh vyshe konkretnyh rezul'tatov naibolee vazhnym sledstviem ih jeksperimentov javilas' demonstracija togo, chto imeetsja vozmozhnost' izuchenija svojstv otdel'nyh oskolkov delenija, ustanovlennyh harakteristikami iz izluchenij (vmesto togo, chtoby izuchat' svojstva srednego oskolka delenija s pomoshh'ju srednej massy i zarjada). Raskryvajutsja preimushhestva jetogo usovershenstvovanija v metode izuchenija oskolkov delenija. (author)}
place = {IAEA}
year = {1965}
month = {Jul}
}