Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Electronic Resource  (21)
Source
Material
  • Electronic Resource  (21)
Years
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Steady flow approximations to the heliumR-process (1983)
    Springer
    Astrophysics and space science 91 (1983), S. 221-234 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract R-process yields for a helium layer have been calculated within a network of 6033 heavy nuclei using a steady flow approximation. The calculation of the neutron capture cross sections has been improved. The beta decay rates computed by Klapdor and his colleagues have been used in the calculation. We find that ther-process yield peaks near mass numbers 80 and 130 require a neutron number density of approximately 1020 cm−3 and a freezing time comparable to or less than 0.1 s. The peak near mass number 195 requires a neutron number density of about 1021 cm−3 and a freezing time comparable to or less than about 0.01 s. The individual yield features of the steady flowr-process depend entirely upon the neutron capture cross sections of the nuclei along the flow path and the beta decay rates, which can shift the flow path and thereby introduce inappropriate capture cross sections into the determination of the yields.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00656111
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Structure in the beta strength function of very neutron-rich Rb-isotopes (1979)
    Springer
    The European physical journal 292 (1979), S. 73-77 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The beta strength functionS β is calculated in a schematical Brown-Bolsterli model for the Gamow-Tellerβ − decay of89–99Rb. The position of the peaks inS β resulting from the back spin flip transitions and the calculated life-times are in good agreement with recent experimental results. A simple regularity is found to govern the energy position of the lowest-lying structures inS β. By calculations of the type given here thus it should be possible to produce much more reliable input data concerningS β forr-orn-process calculations than have been used up to now in astrophysical calculations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01434633
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Determination of fission barrier heights from β-delayed fission (1979)
    Springer
    The European physical journal 292 (1979), S. 249-255 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Beta delayed fission (βDF) gives a possibility to investigate the fission barrier for nuclei far off beta stability. However, before any information on the fission barrier can be extracted, the effect of low-lying structures in the beta-strength function (S β) on theβDF branching ratio has to be considered. This is in general not done. In this paper the lowlying structures that occur inS β are discussed and microscopic calculations for the Gamow-Teller strength function are presented for232Th (β −-decay) and232Pu,240Cm,244,248Cf and248Fm (β +-decay). Using the calculated strength functionsβ +DF branching ratios are calculated and compared with the experimental ones. The sensitivity of the results to different shapes ofS β is investigated. It is concluded that, when the expected structures inS β are considered, there are at present no indications fromβ + DF measurements that the errors in the fission barrier calculations are larger than the uncertainty given for those calculations. The difference in magnitude between theβ − DF and theβ +DF branching ratios is also explained by the occurrence of low-lying structures inS β.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01547469
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Beta-delayed fission and neutron emission: Consequences for the astrophysicalr-process and the age of the galaxy (1983)
    Springer
    The European physical journal 309 (1983), S. 301-317 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Beta-delayed neutron emission and beta-delayed fission probabilities (P n andP β d j ) were calculated for neutron-rich nuclei between the beta stability line and the neutron-drip line in the range 10≦Z≦100 and 75≦Z≦100, respectively. These results were obtained by applying recentβ-strength function calculations, fission barrier height predictions, and a neutron optical potential from infinite nuclear matter calculations. An area of ∼100% fission probability is predicted around Z=94,N=168 extending beyond the well-known island of spontaneous fission in that region. Astrophysicalr-process calculations were performed including the calculatedP n and Pβ d f values. This puts the method to determine the age of the Galaxy by the actinide chronometers on a reliable basis. An excellent overall agreement with the observedr-abundance distribution is obtained. The predictedr-process production ratios for the Chronometrie pairs232Th/238U,235U/238U and244Pu/238U result in an age of the Galaxy oft G =(20.8± 4 2 )×109 a, which is by almost a factor two larger than earlier predictions by this method, but in accordance with recent astronomical observations from globular clusters. The predicted island of 100%β-delayed fission acts as a sink to ther-process with the consequence that no superheavy elements are produced in nature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01413833
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Derp 3/2-Analogzustand in51V (1970)
    Springer
    The European physical journal 238 (1970), S. 11-22 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract In an investigation ofT=7/2 analogue states in51V the50Ti(p, γ) excitation curve has been measured for proton bombarding energies 1280–1480 keV and 2340–2660 keV. From the (p, γ) resonances 29 new virtual levels in the region of 9316–9510 keV excitation energy in51V were determined. The strong resonance atE p=1 371 keV has been identified as the isobaric analogue state of the51Ti ground state by determining spin and parity of this resonance to be 3/2−. There is no evidence for a strong analogue resonance in51V corresponding to the 1.16 MeV p 1/2 state in51Ti. The γ-decay of the p 3/2 analogue state has been studied by measuring branching ratios and angular distributions of primary γ-transitions with a Ge(Li) detector.M1E2 mixing ratios have been determined for these transitions. The total width of the resonance for γ-decay is found to be Γγ=1.6±0.4 eV. New bound levels in51V have been introduced at 3576, 4651 and 4661 keV excitation energy. TheJ π values of the 3085, 4770, and 4863 keV states are determined to be 5/2−, 5/2−, 3/2−, respectively. The analogue-antianalogueM1 transition strength is found to be considerably reduced compared to the situation ins-d shell nuclei.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01399574
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Study of the ground state doublet in57Fe (1973)
    Springer
    The European physical journal 260 (1973), S. 247-252 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The56Fe(d,p)57Fe reaction has been studied at an incident energy of about 10 MeV. The ground state doublet of57Fe has been resolved using the Heidelberg Q 3 D magnetic spectrograph and the Minnesota split-pole spectrograph. The ratio of the spectroscopic strengths (2J+1)S for the transitions to the first excited state at 14.4 keV excitation energy (J π=3/2−) and the ground state (J π=1/2−) has been determined to be 5.80±0.5. This number is of special interest with respect to a possible deformation of the nucleus57Fe and in connection with the corresponding analogue resonances in57Co.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01395983
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Eine Quelle für polarisierte Lithiumkerne (1967)
    Springer
    The European physical journal 199 (1967), S. 68-81 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A source for nuclear polarized lithium-6 and -7 ions was built following the method of separation of the atomic hyperfine states in a strong inhomogeneous magnetic sextupole field and ionisation of the selected atoms by electron bombardment in a weak homogeneous field. The velocity distribution of the atomic beam formed by a Laval nozzle and the focussing properties of the sextupole magnet were determined using a mechanical velocity selector. After separation of the two isotopes the ion beam has an intensity of 10−9 ampere. As no background of unpolarized lithium ions was found, a vector polarisation of (32±1)% and (24±1)% for lithium-6 and -7 and a tensor polarisation of (−32±1)% for lithium-6 can be expected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01326015
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Spin assignments by a high spin selective heavy ion reaction (1973)
    Springer
    The European physical journal 262 (1973), S. 83-94 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The reaction12C(14N,d)24Mg is investigated atE Lab=52 MeV by means or a multigap magnetic spectrograph. Angular distributions of levels between 6.00 and 20.21 MeV are measured using nuclear track emulsions. By quantitative analysis of the angular distributions (FRDWBA- and Hauser-Feshbach calculations), the reaction is shown to proceed almost completely via compound mechanism. The reaction is applied for selective excitation of high spin states in24Mg. Evidence is given by this example that under suitably chosen conditions a complex heavy ion reaction can be a powerful means for spin assignments at high excitation energies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01394810
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    High spin states in106in (1981)
    Springer
    The European physical journal 301 (1981), S. 29-34 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract High spin states have been investigated by the reaction90Zr(19F, 3nγ), using an Anticompton spectrometer device, for the nucleus106In, for which no in-beamγ-spectroscopic information was available up to now. A level scheme has been constructed up to anI =(13,14) state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01412460
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Proton-neutron quasiparticle RPA and charge-changing transitions (1989)
    Springer
    The European physical journal 333 (1989), S. 125-129 
    Details
    ISSN: 1434-601X
    Keywords: 21.60.Jz ; 23.40.Hc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract General formulae for a proton-neutron QRPA calculation are presented. All terms in the RPA order are retained, and no specific assumptions on the residual interaction and one-body charge-changing transitions are made. QRPA phonon correlations are introduced in first-order perturbation for quasiparticle transitions from odd-mass and odd-odd parent nuclei.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01565141
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...