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
  • 1980-1984  (8)
Source
Material
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    The15N(p,α 0)12C reaction at stellar energies (1982)
    Springer
    The European physical journal 305 (1982), S. 325-333 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The15N(ρ, α0)12C reaction has been investigated in the energy range ofE p (lab)=78-810keV. The measurement of the excitation functions and α-particle angular distributions involved solid targets as well as a quasi-point supersonic jet gas target. The determination of absolute cross sections has been carried out with the gas target. The observed energy dependence of the total cross sections can be described in terms of two-level Breit-Wigner shapes including the resonances atE p (J π)=335(1−) and 1,028(1−)keV. The data lead to a zero-energy intercept of the astrophysicalS(E) factor ofS(0)= 65±4MeV-b. The angular distributions are asymmetric around 90° and require an additional amplitude in the reaction mechanism, which interferes predominantly with the 335 keV resonance. The origin of this background amplitude is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01419081
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The4He(12C, γ)16O reaction at stellar energies (1982)
    Springer
    The European physical journal 308 (1982), S. 73-94 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The capture reaction4He(12C, γ)16O (E c.m.= 1.34–3.38 MeV) as well as the elastic scattering process4He(12C,12C)4He (E c.m.=1.44–3.38 MeV) have been investigated with the use of an intense12C beam and a windowless and4He recirculating gas target system. The measurements involved two large NaI(T1) crystals in close geometry to an extended gas target, whereby angle-integrated γ-ray yields were obtained. A large area plastic detector was used for the suppression of time-independent background. A search for cascade γ-ray transitions was carried out by coincidence techniques. The measurement of absolute cross sections is also reported. Theoretical fits of the excitation function for the groundstate γ-ray transition requireE1 as well asE2 capture amplitudes, which are of equal importance at stellar energies. This result increases significantly the stellar burning rate of4He(12C, γ)16O and leads to16O as the dominant product at the end of helium burning in massive stars. The observed capture yield to the 6.92 MeV state is dominated by the direct capture mechanism and plays a small role at stellar energies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01415851
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Destruction of26Al via the26Al(n, p)26Mg-reaction (1984)
    Springer
    The European physical journal 318 (1984), S. 121-122 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The cross section, averaged over a Maxwell-Boltzmann distribution with kT=30 keV, has been measured for the p1-group of the26A1 (n, p)26Mg reaction to be π=4.1±1.2mb. This result is converted into a reaction rate at T9=2.9K and compared with Hauser-Feshbach-calculations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02117223
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The3He(α,γ)7Be reaction and the solar neutrino problem (1982)
    Springer
    The European physical journal 304 (1982), S. 307-332 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The capture reaction3He(α,γ)7Be has been investigated in the energy range ofE c.m. =107 to 1,266 keV. The4He or3He beams of up to 300 μA particle current were incident on3He or4He gas targets, respectively. The gas target systems were all of the windowless and recirculating type. Excitation functions have been obtained with the use of an extended-static gas target, while the measurements ofγ-ray angular distributions involved a quasi-point supersonic jet system. The determination of absolute cross sections has been carried out with both types of gas target systems. Theγ-ray yields in the3He(α,γ)7Be reaction were detected using 80 cm3 Ge(Li) detectors. The data lead to a zero-energy intercept of the astrophysicalS(E) factor ofS(0)=0.30±0.03 keV-b. This result reduces the calculated solar neutrino rate by a factor of 1.76.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01421513
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Resonance strengths of some light nuclei (1982)
    Springer
    The European physical journal 305 (1982), S. 319-323 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The strengths of theE c.m.=324 and 829 keV resonances in19F(ρ, αγ)16O have been determined relative to the Rutherford elastic scattering cross section. With these values as standards, the strengths of theE c.m.=259, {pp143} (also 1,106) and 1,259 keV resonances in14N(ρ, γ)15 O,18O(ρp, γy)19F and14N(α, γ)18F were measured, respectively. In addition, the cross section of the direct capture process in16O(ρ, γ)17F atE c.m.=853 keV has been obtained. All measurements were carried out by interchanging the role of projectiles and target nuclei, i.e.14N,16O,18O and19F ion beams of appropriate energies were guided into windowless gas target systems filled with hydrogen or helium gas. The results are compared with previous work.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01419080
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Search forγ-ray transitions within the5Li groundstate (1983)
    Springer
    The European physical journal 310 (1983), S. 243-245 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A search forγ-ray transitions within the broad groundstate of5Li has been carried out via the4He(p, γp *)4He reaction atE p (lab)=1.5−7.0 MeV. Differentially pumped gas targets of the extended and quasi-point types have been used. The results show that the set-up and detection techniques utilized are not sensitive enough to observe such intrastate transitions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01415229
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The12C+12C reaction at subcoulomb energies (II) (1981)
    Springer
    The European physical journal 303 (1981), S. 305-312 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The reaction12C+12C has been studied in the energy range Ec.m.=2.8–6.3 MeV by charged-particle spectroscopy. Angular distributions of the proton and α-particle exit channels were obtained. The excitation functions do not reveal evidence for the phenomenon of absorption under the barrier. The data have been extrapolated to the energy region of astrophysical interest. The existence of reported and new intermediate resonance structures is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01421528
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Comparison of the fusion reactions12C+20Ne and16O+16O near the Coulomb barrier (1980)
    Springer
    The European physical journal 297 (1980), S. 161-183 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The partial cross sections of heavy residual nuclei produced in the heavy ion fusion of12C+20Ne have been measured atE c.m.=6–15 MeV viaγ-ray spectroscopy with a Ge(Li) detector. Windowless and recirculating gas target systems have been used. The dominant residual nuclei are24Mg,27Al,28Si,30Si,30P and31P, which arise from two- and three-body breakups in the exit channels. The observed excitation functions are smooth in their energy dependence and give no indications for the existence of pronounced resonance structures, in contrast to theoretical predictions. The Coulomb excitation of20Ne served as an intrinsic calibration standard in the determination of absolute partial and total fusion cross sections. The same experimental set-up was also used in the reaction studies of16O+16O atE c.m.=7–14 MeV, going through the same compound nucleus32S at similar excitation energies. The observed energy dependence in the excitation functions is in good agreement with previous work. The total fusion cross section agrees fairly well with two sets of values reported previously, but deviates significantly from other reported absolute cross section values. The relative evaporation distributions of the residual nuclei are similar for both heavy ion reactions. However, the ratio of their total fusion cross sections deviates from model predictions and suggests that compound nucleus formation does depend on the microscopic structure of the colliding nuclei in the entrance channel. From the observed energy dependence of the above ratio, particularly at subcoulomb energies, geometrical effects in the entrance channel (due to deformed and spherical nuclei) appear to be weak. The astrophysical aspects of the data in the context of late stellar nucleosynthesis are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01421473
    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...