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Sahm, C.C.
Technische Hochschule Darmstadt (Germany, F.R.). Fachbereich 5 - Physik1984
Technische Hochschule Darmstadt (Germany, F.R.). Fachbereich 5 - Physik1984
AbstractAbstract
[en] At the velocity filter SHIP of the Society for Heavy Ion Research in Darmstadt cross sections for the evaporation-residual nucleus formation in the reactions 86Kr+sup(121,123)Sb and 124Sn+sup(90,92,94,96)Zr, 100Mo have been measured. The probability for compound-nucleus formation in these reactions was determined by comparison of the measured cross sections with evaporation-residual nucleus cross sections and fusion cross sections from 40Ar-induced reactions which yield the same compound nuclei. It is valid for nearly central collisions of the reaction partners. The fusion probability is compared with the prediction of a conventional fusion model, in which it is described by the transmission coefficient of a one-dimensional potential barrier, at energies near the fusion barrier of the conventional model suppressed by up to three orders of magnitude. It reaches its saturation value one at energies between 9 and 26 MeV higher than expected by the conventional model. The increase of the fusion probability below the saturation value with the energy is very much weaker than expected in the conventional model. The results can be parametrized by means of Gauss-shaped fluctuations of a mean fusion barrier. The measured mean fusion barriers are compared with the prediction of a semiempirical macroscopic model for nucleus-nucleus collisions which predicts a dynamic increase of the fusion barrier for massive systems. (orig./HSI)
[de]
Am Geschwindigkeitsfilter SHIP der Gesellschaft fuer Schwerionenforschung in Darmstadt sind Wirkungsquerschnitte fuer Verdampfungsrestkernbildung in den Reaktionen 86Kr+sup(121,123)Sb und 124Sn+sup(90,92,94,96)Zr, 100Mo gemessen worden. Die Wahrscheinlichkeit fuer Compoundkernbildung in diesen Reaktionen wurde durch Vergleich der gemessenen Wirkungsquerschnitte mit Verdampfungsrestkernquerschnitten und Fusionsquerschnitten aus 40Ar induzierten Reaktionen, die dieselben Compoundkerne ergeben, bestimmt. Sie ist gueltig fuer nahezu zentrale Stoesse der Reaktionspartner. Die Fusionswahrscheinlichkeit ist, verglichen mit der Vorhersage eines konventionellen Fusionsmodells, in dem sie durch den Transmissionskoeffizienten einer eindimensionalen Potentialbarriere beschrieben wird, bei Energien nahe der Fusionsbarriere des konventionellen Modells um bis zu drei Groessenordnungen unterdrueckt. Sie erreicht ihren Saettigungswert eins bei Energien zwischen 9 und 26 MeV hoeher als nach dem konventionellen Modell erwartet. Die Zunahme der Fusionswahrscheinlichkeit unterhalb des Saettigungswertes mit der Energie ist sehr viel schwaecher als im konventionellen Modell erwartet. Die Ergebnisse koennen parametrisiert werden mit Hilfe gaussfoermiger Fluktuationen einer mittleren Fusionsbarriere. Die gemessenen mittleren Fusionsbarrieren werden mit der Vorhersage eines semiempirischen makroskopischen Modells fuer Kern-Kern-Stoesse verglichen, das eine dynamische Erhoehung der Fusionsbarriere fuer massive Systeme vorhersagt. (orig./HSI)Original Title
Schwellenverhalten der Compoundkernbildung in den Reaktionen Kr+Sb, Sn+Zr und Sn+Mo
Primary Subject
Source
6 Jul 1984; 81 p; Diss. (Dr.rer.nat.).
Record Type
Miscellaneous
Literature Type
Thesis/Dissertation; Numerical Data
Report Number
Country of publication
ACTINIUM ISOTOPES, ALPHA PARTICLES, ANTIMONY 121 TARGET, ANTIMONY 123 TARGET, COMPOUND-NUCLEUS REACTIONS, ENERGY DEPENDENCE, EVAPORATION MODEL, EXCITATION FUNCTIONS, EXPERIMENTAL DATA, FRANCIUM ISOTOPES, HEAVY ION FUSION REACTIONS, HEAVY NUCLEI, INTEGRAL CROSS SECTIONS, KRYPTON 86 REACTIONS, MEV RANGE 100-1000, MOLYBDENUM 100 TARGET, NEUTRONS, PROTONS, RADIUM ISOTOPES, THORIUM ISOTOPES, TIN 124 REACTIONS, ZIRCONIUM 90 TARGET, ZIRCONIUM 92 TARGET, ZIRCONIUM 94 TARGET, ZIRCONIUM 96 TARGET
BARYONS, CATIONS, CHARGED PARTICLES, CROSS SECTIONS, DATA, ELEMENTARY PARTICLES, ENERGY RANGE, FERMIONS, HADRONS, HEAVY ION REACTIONS, HELIUM IONS, HYDROGEN IONS, HYDROGEN IONS 1 PLUS, INFORMATION, IONIZING RADIATIONS, IONS, MATHEMATICAL MODELS, MEV RANGE, NUCLEAR MODELS, NUCLEAR REACTIONS, NUCLEI, NUCLEONS, NUCLEOSYNTHESIS, NUMERICAL DATA, RADIATIONS, SYNTHESIS, TARGETS
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Vandenbosch, R.; Murakami, T.; Sahm, C.C.; Leach, D.D.; Ray, A.; Murphy, M.J.
Washington Univ., Seattle (USA). Nuclear Physics Lab1985
Washington Univ., Seattle (USA). Nuclear Physics Lab1985
AbstractAbstract
[en] The mean-square spin value of the compound nucleus 248Cf has been determined from fission fragment angular distributions for the 12C+236U and 16O+232Th reactions. The anisotropy and hence the mean-square spin values are much larger than expected. Models which reproduce the enhancement observed in the sub-barrier fusion excitation functions fail to account for the spin distribution observations. 12 refs., 3 figs
Primary Subject
Source
1985; 12 p; Available from NTIS, PC A02/MF A01; 1 as DE86004305; Portions of this document are illegible in microfiche products.
Record Type
Report
Literature Type
Numerical Data
Report Number
Country of publication
ACTINIDE NUCLEI, ALPHA DECAY RADIOISOTOPES, ANGULAR MOMENTUM, CALIFORNIUM ISOTOPES, DATA, DAYS LIVING RADIOISOTOPES, DISTRIBUTION, EVEN-EVEN NUCLEI, HEAVY ION REACTIONS, HEAVY NUCLEI, INFORMATION, ISOTOPES, NUCLEAR FRAGMENTS, NUCLEAR REACTIONS, NUCLEI, NUMERICAL DATA, PARTICLE PROPERTIES, RADIOISOTOPES, TARGETS
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Sahm, C.C.; Murakami, T.; Vandenbosch, R.; Leach, D.D.; Murphy, M.J.; Ray, A.
Gross properties of nuclei and nuclear excitations1986
Gross properties of nuclei and nuclear excitations1986
AbstractAbstract
[en] The mean-square spin value of the compound nucleus has been determined from fission fragment angular distributions for the reactions 236U(12C,f), 232Th(16O,f) and 208Pb(16O,f). Currently used fusion models which successfully describe the fusion excitation function fail to reproduce the observed large spin values. (orig.)
Primary Subject
Secondary Subject
Source
Feldmeier, H. (ed.); Technische Hochschule Darmstadt (Germany, F.R.). Inst. fuer Kernphysik; Gesellschaft fuer Schwerionenforschung m.b.H., Darmstadt (Germany, F.R.); 297 p; 1986; p. 252-258; 14. international workshop on gross properties of nuclei and nuclear excitations; Hirschegg (Austria); 13-18 Jan 1986; Available from Technische Hochschule Darmstadt (Germany, F.R.). Inst. fuer Kernphysik
Record Type
Miscellaneous
Literature Type
Conference
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Keller, J.G.; Schmidt, K.H.; Hebberger, F.P.; Muenzenberg, G.; Reisdorf, W.; Clerc, H.G.; Sahm, C.C.
Proceedings of the symposium on the many facets of heavy ion fusion reactions1986
Proceedings of the symposium on the many facets of heavy ion fusion reactions1986
AbstractAbstract
[en] Sub-barrier fusion was studied with zirconium projectiles on various intermediate mass targets in the energy range 160-200 MeV at the UNILAC facility. Single evaporation residues were identified and cross sections for different excitation channels were determined. Fusion probabilities averaged over angular momenta which give rise to the residues were determined. Barrier distributions for the systems considered were obtained. Results are compared to coupled channel calculations
Primary Subject
Secondary Subject
Source
Argonne National Lab., IL (USA); p. 533-540; 1986; p. 533-540; Symposium on the many facets of heavy ion fusion reactions; Argonne, IL (USA); 24-26 Mar 1986; Available from NTIS, PC A99/MF A01; 1 as DE87010055
Record Type
Report
Literature Type
Conference; Numerical Data
Report Number
Country of publication
ALPHA DECAY, ANGULAR MOMENTUM, COUPLED CHANNEL THEORY, CROSS SECTIONS, DEEP INELASTIC HEAVY ION REACT, ENERGY DEPENDENCE, EXCITATION FUNCTIONS, EXPERIMENTAL DATA, FISSION, HEAVY ION FUSION REACTIONS, MASS NUMBER, MEV RANGE 100-1000, MOLYBDENUM 94 TARGET, TIME-OF-FLIGHT METHOD, TRANSFER REACTIONS, UNILAC, YTTRIUM 89 TARGET, ZIRCONIUM 90 REACTIONS, ZIRCONIUM 90 TARGET, ZIRCONIUM 92 TARGET, ZIRCONIUM 96 TARGET
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Schmidt, K.H.; Simon, R.S.; Keller, J.G.; Hessberger, F.P.; Muenzenberg, G.; Quint, B.; Clerc, H.G.; Schwab, W.; Gollerthan, U.; Sahm, C.C.
Gesellschaft fuer Schwerionenforschung m.b.H., Darmstadt (Germany, F.R.)1985
Gesellschaft fuer Schwerionenforschung m.b.H., Darmstadt (Germany, F.R.)1985
AbstractAbstract
[en] The γ rays emitted in the radiative-fusion reaction 90Zr + 90Zr -> 180Hg + xγ were measured. No indication was found for a specific direct capture process associated with a high-energy γ ray. The shape of the observed γ spectrum is compatible with a statistical deexcitation of the compound nucleus. (orig.)
Primary Subject
Source
Oct 1985; 11 p; Available from Gesellschaft fuer Schwerionenforschung m.b.H., Darmstadt (Germany, F.R.); Submitted to Phys. Lett.
Record Type
Report
Literature Type
Numerical Data
Report Number
Country of publication
BARYONS, BOSONS, DATA, ELEMENTARY PARTICLES, ENERGY RANGE, ENERGY-LEVEL TRANSITIONS, EVEN-EVEN NUCLEI, EVEN-ODD NUCLEI, FERMIONS, HADRONS, HEAVY ION REACTIONS, INFORMATION, INTERMEDIATE MASS NUCLEI, MASSLESS PARTICLES, MERCURY ISOTOPES, MEV RANGE, NUCLEAR CASCADES, NUCLEAR REACTIONS, NUCLEI, NUCLEONS, NUCLEOSYNTHESIS, NUMERICAL DATA, SPECTRA, SYNTHESIS, TARGETS
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] A prescription for the error analysis of experimental data in the case of stochastic background is formulated. Several relations are given which allow to establish the significance of mother-daughter relationships obtained from delayed coincidences. Both, the probability that a cascade is produced randomly and the probability that the parameters of an observed event chain are incompatible with known properties of a given species are formulated. The expressions given are applicable also in cases of poor statistics down even to single events. (orig.)
Primary Subject
Secondary Subject
Source
Record Type
Journal Article
Literature Type
Numerical Data
Journal
Zeitschrift fuer Physik. A, Atoms and Nuclei; ISSN 0340-2193; 
; v. 316(1); p. 19-26
; v. 316(1); p. 19-26
Country of publication
ACTINIUM ISOTOPES, ALPHA SPECTRA, BACKGROUND NOISE, CASCADE THEORY, COINCIDENCE METHODS, CORRELATIONS, COUNTING TECHNIQUES, ENERGY SPECTRA, ERRORS, EXPERIMENTAL DATA, FRANCIUM ISOTOPES, HEAVY ION FUSION REACTIONS, HYDROGEN ISOTOPES, INCLUSIVE INTERACTIONS, LIFETIME, MEV RANGE 100-1000, NEUTRONS, RADIUM ISOTOPES, RADON ISOTOPES, RANDOMNESS, STATISTICS, STOCHASTIC PROCESSES, THORIUM ISOTOPES, TIN 124 REACTIONS, ZIRCONIUM 96 TARGET
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
No abstract available
Original Title
Alphazerfallseigenschaften der neutronenarmen Nuklide 199Rn und sup(199m)Rn
Primary Subject
Source
Conferences on nuclear physics - particle physics; Karlsruhe, Germany, F.R; 22 - 27 Mar 1982; Published in summary form only.
Record Type
Journal Article
Literature Type
Conference
Journal
Verhandlungen der Deutschen Physikalischen Gesellschaft; ISSN 0420-0195; ; v. 17(6); p. 1098
; v. 17(6); p. 1098
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
No abstract available
Primary Subject
Source
Gesellschaft fuer Schwerionenforschung m.b.H., Darmstadt (Germany, F.R.); 302 p; Jul 1980; p. 125; Published in summary form only.
Record Type
Report
Literature Type
Numerical Data
Report Number
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] A new α-line with Esub(α) = 9.912 +- 0.020 MeV is assigned to an isomeric state in 216Th. It decays with a half-life of Tsub(1/2) = 180 +- 40 μs. There are indications for a dominating ß-branch. (orig.)
Primary Subject
Source
Record Type
Journal Article
Literature Type
Numerical Data
Journal
Nuclear Physics. A; ISSN 0375-9474; ; v. 404(1); p. 51-57
; v. 404(1); p. 51-57
Country of publication
ALPHA DECAY, ALPHA SPECTRA, ARGON 40 REACTIONS, BRANCHING RATIO, ENERGY DEPENDENCE, ENERGY SPECTRA, EXPERIMENTAL DATA, GAMMA DECAY, HAFNIUM 178 TARGET, HAFNIUM 179 TARGET, HAFNIUM 180 TARGET, HALF-LIFE, HEAVY ION FUSION REACTIONS, INTEGRAL CROSS SECTIONS, ISOMERIC NUCLEI, MEV RANGE 100-1000, NEUTRONS, PROTONS, TANTALUM 181 TARGET, THORIUM 216, TIN 124 REACTIONS, ZIRCONIUM 94 TARGET, ZIRCONIUM 96 TARGET
ACTINIDE NUCLEI, BARYONS, CATIONS, CHARGED PARTICLES, CROSS SECTIONS, DATA, DECAY, ELEMENTARY PARTICLES, ENERGY RANGE, EVEN-EVEN NUCLEI, FERMIONS, HADRONS, HEAVY ION REACTIONS, HEAVY NUCLEI, HYDROGEN IONS, HYDROGEN IONS 1 PLUS, INFORMATION, IONS, MEV RANGE, NUCLEAR DECAY, NUCLEAR REACTIONS, NUCLEI, NUCLEONS, NUCLEOSYNTHESIS, NUMERICAL DATA, SPECTRA, TARGETS, THORIUM ISOTOPES
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
No abstract available
Original Title
Systematische Untersuchung von Wirkungsquerschnitten fuer die Bildung neutronenarmer Verdampfungsrestkerne zwischen At und Pa
Primary Subject
Source
Conferences on nuclear physics - particle physics; Karlsruhe, Germany, F.R; 22 - 27 Mar 1982; Published in summary form only.
Record Type
Journal Article
Literature Type
Conference
Journal
Verhandlungen der Deutschen Physikalischen Gesellschaft; ISSN 0420-0195; ; v. 17(6); p. 1107
; v. 17(6); p. 1107
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
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