Qucosa – Hemholtz-Zentrum Dresden-Rossendorf
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Contribution of the massive photon decay channel to the neutrino cooling of neutron stars
Get PDFThe role of the massive photon decay via intermediate states of electron-electron-holes and proton-proton-holes into neutrino-anti-neutrino pairs in the course of neutron star cooling is investigated. These reactions may ba operative in hot neutron stars in the region of proton pairing. The corresponding contribution to the neutrino emissivity is calculated. It varies with the temperature as T3/2e−mγ/T for T < m γ, where mγ is an effective photon mass in superconducting matter. Estimates show that this process appears as strong cooling channel of neutron stars at temperatures T ≈ ( 10^9 - 10^10) K
Asymmetry of the Dielectron Emission Rate in an Isospin-Asymmetric Pion Medium
Get PDFAsymmetry of the Dielectron Emission Rate in an Isospin-Asymrnetric Pion Medium T.I. GULANOVA,1 A. I. TITOV Bogoliubov Theoretical Laboratory, Joint Institute for Nuclear Research, 141980 Dubna, Russia B. Kämpfer Research Center Rossendorf, Institute for Nuclear and Hadron Physics, PF 510119, 01314 Dresden, Germany Institute for Theoretical Physics, Technical University Dresden, Mommsenstr. 13, 01062 Dresden, Germany Abstract The dielectron emission by pion annihilation in an isospin-asymmetric pion gas at finite temperature is considered. Due to the differente between the longitudinal and tramverse parts of the in-medium p meson self-energy a specific asymmetry of the rates is caused for electron pairs with relative momenta perpendicular or parallel to the total pair momentum. This asymmetry may be considered as a sensitive signal of in-medium-modifications of the p properties. 1Permanent- address: Physical and Technical Institute of Uzbek Academy of Sciences, 700084 Tashkent, RepubIic Uzbekista
Zur Herausbildung verschiedener Zeitskalen beim Zerfall von Compoundkern-Resonanzen als Folge des Trapping-Effekts
Get PDF1% Cold leg break experiment on PMK-2 Test results and computer code analysis
Get PDFIn the framework of the computer code assessment programme for the VVER-440 type Paks Nuclear Power Plant a 1% cold leg break experiment has been conducted on the PMK-2 integral type test facility. It was followed by calculations using RELAP 5Mod3.1 and ATHLET in order to assess code capabilities. This experiment was started from the nominal operational parameters and it was considered that only the high pressure injection system (HPIS) is available and there is no injection from the safety injection tanks (SIT). This experiment was the repetition of the test measured in 1990 with improved data aquisition system. The first part of this report includes a short description of the facility, the measurement description, the test results including the local void measurement and a short interpretation of the main phenomena. In the second part of the report the analysis performed by the RELAP 5Mod3.1 and ATHLET Mod1.1 Cycle A codes are given
