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Two-phonon-octupole excitation in {sup 208}Pb; Zwei-Phononen-Oktupol-Anregung in {sup 208}Pb

Abstract

In the framework of the present thesis quasi-elastic processes in the reactions {sup 206} Pb+{sup 208} Pb and {sup 208} Pb+{sup 208} Pb were studied at an incident energy slightly above the Coulomb barrier (6.2 MeV/u) were studed. By means of the measured Particle-gamma correlations the quasi-elastic collisions were separated from the deep inelastic ones. Determined were the absolute cross sections and angular distributions of the exitation by inelastic collisions as well as by one- and two-neutron transfer. For the states excited by inelatic scattering the multiplicities of the {gamma} quanta emitted in their decay were experimentally determined. The measured angular distributions of the inelastic reactions were compared with CCBA calculations. As most important result of this thesis the experimental detection of a member of the 2-phonon-octupole multiplet is to be considered. A hitherto unknown {gamma} transition in the spectrum of {sup -}2{sup -}0{sup -}8 Pb with an energy of 2.485 MeV was detected. Because of the measured {gamma}{gamma} coincidence ratios in {sup 208} Pb this transition was assigned to the level scheme of {sup 208}Pb. Its decay to the 1-phonon state 3{sup -} pursues via an E1-transition to the 5{sup -} -state and a following E2-transition. The angular distribution  More>>
Authors:
Publication Date:
Jun 01, 1992
Product Type:
Thesis/Dissertation
Report Number:
GSI-92-14
Reference Number:
SCA: 663450; 663110; 663220; 663580; PA: DEN-92:016357; SN: 93000906087
Resource Relation:
Other Information: TH: Diss. (Dr.rer.nat.); PBD: Jun 1992
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; LEAD 208 TARGET; LEAD 206 REACTIONS; LEAD 208 REACTIONS; INELASTIC SCATTERING; NEUTRON TRANSFER; LEAD 208; ROTATIONAL STATES; GAMMA CASCADES; LEAD 205; LEAD 206; LEAD 207; LEAD 209; LEAD 210; ONE-NUCLEON TRANSFER REACTIONS; DIFFERENTIAL CROSS SECTIONS; DWBA; ANGULAR DISTRIBUTION; WOODS-SAXON POTENTIAL; OPTICAL MODELS; EXPERIMENTAL DATA; DE-EXCITATION; SPIN; GEV RANGE 01-10; PARITY; COUPLED CHANNEL BORN APPROXIMATION; MULTIPOLARITY; E1-TRANSITIONS; E2-TRANSITIONS; E3-TRANSITIONS; GAMMA RADIATION; PHOTONS; GAMMA SPECTRA; ENERGY SPECTRA; INTEGRAL CROSS SECTIONS; COULOMB EXCITATION; INTERFERENCE; TWO-NUCLEON TRANSFER REACTIONS; 663450; 663110; 663220; 663580; HEAVY-ION-INDUCED REACTIONS AND SCATTERING; GENERAL AND AVERAGE PROPERTIES OF NUCLEI AND NUCLEAR ENERGY LEVELS; ELECTROMAGNETIC TRANSITIONS; A = 190-219
OSTI ID:
10106187
Research Organizations:
Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Frankfurt Univ. (Germany). Fachbereich 13 - Physik
Country of Origin:
Germany
Language:
German
Other Identifying Numbers:
Other: ON: DE93744614; TRN: DE9216357
Availability:
OSTI; NTIS (US Sales Only); INIS
Submitting Site:
DEN
Size:
95 p.
Announcement Date:
Jun 30, 2005

Citation Formats

Martin, N. Two-phonon-octupole excitation in {sup 208}Pb; Zwei-Phononen-Oktupol-Anregung in {sup 208}Pb. Germany: N. p., 1992. Web.
Martin, N. Two-phonon-octupole excitation in {sup 208}Pb; Zwei-Phononen-Oktupol-Anregung in {sup 208}Pb. Germany.
Martin, N. 1992. "Two-phonon-octupole excitation in {sup 208}Pb; Zwei-Phononen-Oktupol-Anregung in {sup 208}Pb." Germany.
@misc{etde_10106187,
title = {Two-phonon-octupole excitation in {sup 208}Pb; Zwei-Phononen-Oktupol-Anregung in {sup 208}Pb}
author = {Martin, N}
abstractNote = {In the framework of the present thesis quasi-elastic processes in the reactions {sup 206} Pb+{sup 208} Pb and {sup 208} Pb+{sup 208} Pb were studied at an incident energy slightly above the Coulomb barrier (6.2 MeV/u) were studed. By means of the measured Particle-gamma correlations the quasi-elastic collisions were separated from the deep inelastic ones. Determined were the absolute cross sections and angular distributions of the exitation by inelastic collisions as well as by one- and two-neutron transfer. For the states excited by inelatic scattering the multiplicities of the {gamma} quanta emitted in their decay were experimentally determined. The measured angular distributions of the inelastic reactions were compared with CCBA calculations. As most important result of this thesis the experimental detection of a member of the 2-phonon-octupole multiplet is to be considered. A hitherto unknown {gamma} transition in the spectrum of {sup -}2{sup -}0{sup -}8 Pb with an energy of 2.485 MeV was detected. Because of the measured {gamma}{gamma} coincidence ratios in {sup 208} Pb this transition was assigned to the level scheme of {sup 208}Pb. Its decay to the 1-phonon state 3{sup -} pursues via an E1-transition to the 5{sup -} -state and a following E2-transition. The angular distribution of the 2-phonon-octupole state was calculated in the framework of the CCBA and compared with the experiment. The comparison with the CCBA calculation indicates a spin of I{sup {pi}}=6{sup +} or 4{sup +} . The experimental angular distributions of the one-neutron transfer reactions to {sup 207} Pb and {sup 209} Pb were compared with DWBA calculations. (orig./HSI). [Deutsch] Im Rahmen der vorliegenden Arbeit wurden quasielastische Prozesse bei den Reaktionen {sup 206} Pb+ {sup 208} Pb und {sup 208} Pb+ {sup 208} Pb bei einer Einschussenergie leicht oberhalb der Coulombbarriere (6.2 MeV/u) untersucht. Mit Hilfe der gemessenen Teilchen-Gamma-Korrelationen wurden die quasielastischen Stoesse von den tiefinelastischen separiert. Ermittelt wurden die absoluten Wirkungsquerschnitte und Winkelverteilungen der Anregung durch inelastische Stoesse sowie durch Ein- und Zweineutronentransfer. Fuer die durch inelastische Streuung angeregten Zustaende wurden Multiplizitaeten der bei ihrem Zerfall ausgesandten {gamma}-Quanten experimentell bestimmt. Die gemessenen Winkelverteilungen der inelastischen Reaktionen wurden mit CCBA-Rechnungen verglichen. Daraus wurden optischen Parameter fuer die untersuchten Systeme bestimmt. Als wichtigstes Ergebnis dieser Arbeit ist der experimentelle Nachweis eines Mitglieds des 2-Phononen-Oktupol-Multipletts anzusehen. Es wurde ein bislang unbekannter {gamma}-Uebergang in das Niveauschema von {sup 208}Pb eingeordnet. Sein Zerfall zum 1-Phonon-Zustand 3{sup -} erfolgt ueber einen E1-Uebergang in den 5{sup -}-Zustand und einen anschliessenden E2-Uebergang. Die Winkelverteilung des 2-Phononen-Oktupol-Zustands wurde im Rahmen der CCBA berechnet und mit dem Experiment verglichen. Der Vergleich mit der CCBA-Rechnung deutet auf einen Spin von I{sup {pi}} = 6{sup +} oder 4{sup +} hin. Die experimentellen Winkelverteilungen der Ein-Neutronen-Transfer-Reaktionen zu {sup 207} Pb und {sup 209} Pb wurden mit DWBA-Rechnungen verglichen. (orig./HSI).}
place = {Germany}
year = {1992}
month = {Jun}
}