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Improved method for lifetime measurements; Methode perfectionnee de mesure de la duree de vie; Usovershenstvovannyj metod izmereniya vremeni zhizni; Metodo perfeccionado para medir la vida media de los estados de excitacion

Conference:

Abstract

The measurement of the lifetime of excited states of nuclei is mostly based on the measurement of the delay of a {gamma}-ray (II) in respect to another {gamma}-ray (I) or a {beta}-particle. Organic scintillators allow the best time resolution for the measurement of this decay time, but for complicated decay schemes the identification of {gamma}-energy is important and best achieved by NaI(Tl) scintillators. To combine the merits of both detectors the {gamma}-ray (II) is at first scattered in an organic crystal (stilbene) and the scattered quantum is detected in a Nal(Tl) crystal. In order to allow large acceptance angles between the two scintillators, the measurement of the {gamma}-energy is achieved after adding the pulse heights of both scintillation pulses. To allow a reliable function of the adding unit the pulses from the organic crystal pass first through a gate circuit which is triggered by coincidence between the two scintillators. The pulse spectrum from the adding unit is fed to a single-channel analyser for energy selection. {gamma}-ray (I) is detected in another organic crystal. Fast pulses from both organic scintillators go to a time-to-pulse-height converter and multichannel analyser. This analyser is gated by a slow coincidence between the pulse-height discriminators. (author)  More>>
Authors:
Weinzierl, P; Bartl, W [1] 
  1. Oesterreichische Studiengesellschaft fuer Atomenergie, Seibersdorf (Austria)
Publication Date:
Apr 15, 1962
Product Type:
Conference
Resource Relation:
Conference: Conference on Nuclear Electronics, Belgrade, Yugoslavia (Serbia), 15-20 May 1961; Other Information: 5 figs; Related Information: In: Nuclear Electronics III. Proceedings of the Conference on Nuclear Electronics. V. III| 544 p.
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CRYSTALS; DISCRIMINATORS; EXCITED STATES; GATING CIRCUITS; LIFETIME; NAI DETECTORS; PULSES; SODIUM IODIDES; STILBENE; TIME RESOLUTION
OSTI ID:
22082837
Research Organizations:
International Atomic Energy Agency, Vienna (Austria)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA12N2055041836
Submitting Site:
INIS
Size:
page(s) 223-229
Announcement Date:
Apr 12, 2013

Conference:

Citation Formats

Weinzierl, P, and Bartl, W. Improved method for lifetime measurements; Methode perfectionnee de mesure de la duree de vie; Usovershenstvovannyj metod izmereniya vremeni zhizni; Metodo perfeccionado para medir la vida media de los estados de excitacion. IAEA: N. p., 1962. Web.
Weinzierl, P, & Bartl, W. Improved method for lifetime measurements; Methode perfectionnee de mesure de la duree de vie; Usovershenstvovannyj metod izmereniya vremeni zhizni; Metodo perfeccionado para medir la vida media de los estados de excitacion. IAEA.
Weinzierl, P, and Bartl, W. 1962. "Improved method for lifetime measurements; Methode perfectionnee de mesure de la duree de vie; Usovershenstvovannyj metod izmereniya vremeni zhizni; Metodo perfeccionado para medir la vida media de los estados de excitacion." IAEA.
@misc{etde_22082837,
title = {Improved method for lifetime measurements; Methode perfectionnee de mesure de la duree de vie; Usovershenstvovannyj metod izmereniya vremeni zhizni; Metodo perfeccionado para medir la vida media de los estados de excitacion}
author = {Weinzierl, P, and Bartl, W}
abstractNote = {The measurement of the lifetime of excited states of nuclei is mostly based on the measurement of the delay of a {gamma}-ray (II) in respect to another {gamma}-ray (I) or a {beta}-particle. Organic scintillators allow the best time resolution for the measurement of this decay time, but for complicated decay schemes the identification of {gamma}-energy is important and best achieved by NaI(Tl) scintillators. To combine the merits of both detectors the {gamma}-ray (II) is at first scattered in an organic crystal (stilbene) and the scattered quantum is detected in a Nal(Tl) crystal. In order to allow large acceptance angles between the two scintillators, the measurement of the {gamma}-energy is achieved after adding the pulse heights of both scintillation pulses. To allow a reliable function of the adding unit the pulses from the organic crystal pass first through a gate circuit which is triggered by coincidence between the two scintillators. The pulse spectrum from the adding unit is fed to a single-channel analyser for energy selection. {gamma}-ray (I) is detected in another organic crystal. Fast pulses from both organic scintillators go to a time-to-pulse-height converter and multichannel analyser. This analyser is gated by a slow coincidence between the pulse-height discriminators. (author) [French] La mesure de la duree de vie des etats excites des noyaux repose essentiellement sur celle du retard d'un rayon gamma (II) par rapport a un autre rayon gamma (I) ou a une particule beta. Les scintillateurs organiques permettent de mesurer cette duree de vie avec la meilleure resolution en temps; toutefois, pour les processus des excitations complexes, il est important de determiner l'energie gamma; les scintillateurs a NaI(Tl) sont les plus indiques a cette fin. Pour combiner les avantages de ces deux types de detecteurs, les rayons gamma (II) sont d'abord diffuses dans un cristal organique (stilbene); le quantum emergeant est ensuite detecte dans un cristal de Nal(Tl). Pour assurer une grande liberte de disposition geometrique entre les deux scintillateurs, on mesure l'energie gamma apres avoir additionne les amplitudes des impulsions issues de l'un et l'autre detecteur. La precision de fonctionnement du dispositif additionneur est obtenue en faisant d'abord passer les impulsions provenant du cristal organique dans un conditionneur qui ne s'ouvre que s'il y a coincidence entre les deux scintillateurs. Le spectre des impulsions fourni par le dispositif additionneur est transmis a un selecteur a un seul canal pour selection de l'energie gamma. Les rayons gamma (I) sont detectes dans un autre cristal organique. Les impulsions rapides issues des deux scintillateurs organiques sont appliquees a un convertisseur temps-amplitude et a un selecteur multicanaux. Ce selecteur est declenche par coincidence differee entre les discriminateurs d'amplitude des impulsions. (author) [Spanish] Las mediciones de la vida media de los estados excitados de los nucleos se basan en general en la medicion del retardo de un rayo {gamma} (II) respecto de otro rayo {gamma} (I) o de una particula {beta}. Los contadores de centelleo organicos dan el mejor tiempo de resolucion para dicha medida; pero cuando se presentan esquemas complejos de desintegracion, la identificacion de la energia y es importante y la mejor manera de lograrla es mediante detectores de Nal(TI). Para combinar las ventajas de ambos detectores, el rayo {gamma} (II) se hace incidir primeramente sobre un cristal organico (estilbeno) y el quantum de dispersion se detecta en un cristal de Nal(TI). Con el objeto de permitir grandes angulos de admision entre los dos detectores, la medicion de la energia {gamma} se efectua despues de sumar las alturas de los impulsos correspondientes de ambos detectores. Para asegurar el funcionamiento correcto del dispositivo sumador, los impulsos provenientes del cristal organico se hacen pasar primeramente por un circuito de puerta, accionado por cada coincidencia entre los dos detectores. El espectro de impulsos del dispositivo sumador se hace incidir sobre un analizador de un solo canal para la seleccion de la energia deseada. El rayo {gamma} (I) se detecta en otro cristal organico. Los impulsos rapidos de ambos detectores organicos pasan a un convertidor tiempo-altura de impulsos y a un analizador multicanal. Este analizador se hace actuar como puerta mediante una coincidencia lenta entre los discriminadores de alturas de impulsos. (author) [Russian] Izmerenie vremeni zhizni yadra v vozbuzhdennom sostoyanii obychno osnovano na izmerenii otstavaniya odnogo gamma-lucha (II) po otnosheniyu k drugomu gamma-luchu (I) ili k beta-chastitse. Organicheskie stsintillyatory dayut nailuchshuyu razreshayushchuyu sposobnost' po vremeni dlya izmereniya vremeni takogo raspada, no dlya slozhnykh protsessov raspada opredelenie gamma-ehnergii predstavlyaet bol'shoe znachenie i mozhet byt' luchshe vsego dostignuto stsintillyatorami s kristallom NaI(Tl). Dlya sovmestnogo ispol'zovaniya preimushchestv detektorov togo i drugogo tipa gamma-luch (II) prezhde vsego rasseivaetsya v organicheskom kristalle (stil'ben), a rasseyannyj kvant detektiruetsya kristallom Nal(Tl). Dlya osushchestvleniya bol'shikh uglov priemki mezhdu dvumya stsintillyatorami izmerenie gamma-ehnergii dostigaetsya posle slozheniya amplitudy oboikh stsintillyatsionnykh impul'sov. Dlya obespecheniya nadezhnogo dejstviya ustanovki dlya slozheniya postupayushchie iz organicheskogo kristalla impul'sy prokhodyat prezhde vsego cherez strobiruyushchuyu skhemu, kotoraya initsiiruetsya sovpadeniem mezhdu dvumya stsintillyatorami. Spektr impul'sov, postupayushchij iz ustanovki dlya slozheniya, napravlyaetsya v odnokanal'nyj analizator dlya otbora po ehnergii. Gamma-luch (I) detektiruetsya v drugom organicheskom kristalle. Bystrye impul'sy oboikh organicheskikh stsintillyatorov napravlyayutsya v amplitudno-vremennoj preobrazovatel' impul'sov i v mnogokanal'nyj analizator. EHtot analizator initsiiruetsya medlennym sovpadeniem mezhdu amplitudnymi diskriminatorami impul'sov. (author)}
place = {IAEA}
year = {1962}
month = {Apr}
}