THE STUDY OF THE DEPENDENCE OF THE BETA DECAY RATES IN R-PROCESS NUCLEI ON MASS NUMBER (A) BY PYATOV METHOD

Abstract

In this study,  the dependence of the beta decay rates in r-process nuclei on mass number has been investigated by using Pyatov Method within the framework of the quasi-particle Random Phase Approzimation(QRPA). In this respect, first of all, half lives for have been calculated for ^68-78Ni isotopes lying around N=50, Z= 28 region and in the mass region of A=60-90. Then, the variation  of the calculated half lives with respect to mass number has been investigated and compared with the available experimental results.It has been seen that our calculation results obtained for regions mentioned above  are not so far from the experimental results.Moreover, in order to see whether Pyatov method is successful or not in explaining the half lives of nuclei in different regions, half lives for ^124-132Cd isotopes near N=82, Z=50 region have also been calculated in additon to the above calculations, and compared with the corresponding experimental values. 

Keywords

• R-process,beta decay rate,Gamow-Teller transitions

PYATOV YÖNTEMİYLE R SÜRECİ ÇEKİRDEKLERDE BETA BOZUNUM HIZLARININ KÜTLE NUMARASINA (A) BAĞLILIĞININ İNCELENMESİ

Abstract

Bu çalışmada, Pyatov yöntemi kullanılarak R süreci çekirdeklerde beta bozunum hızlarının kütle numarasına olan bağlılığı kuazi parçacık rastgele faz yaklaşımı (QRPA) çerçevesinde incelendi ve öncelikle A=60-90 bölgesinde ve N=50, Z=28 yakınlarında yer alan ^68-78Ni izotopları için yarı ömür değerleri hesaplandı. Daha sonra bu değerlerin kütle numarasına göre değişimleri incelendi ve mevcut deneysel sonuçlarla karşılaştırıldı. Yukarıda bahsettiğimiz bölgeler için elde edilen sonuçlarımızın deneysel değerlerden çok da uzak olmadığı görüldü. Ayrıca, Pyatov yönteminin farklı bölgelerdeki çekirdeklerde yarı ömür değerlerini açıklamada ne kadar başarılı olduğunu görmek amacıyla yukarıda bahsettiğimiz hesaplara ek olarak, N=82, Z=50 bölgesi civarındaki ^124-132Cd izotopları için de yarı ömür değerleri hesaplandı ve sonuçlarımız deneysel değerlerle karşılaştırıldı.

Keywords

• R- süreci,beta bozunum hızı,Gamow-Teller geçişleri

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