234-238U ve 231,233Pa ÇEKİRDEKLERİNİN (n,f) TESİR KESİTLERİNİN HESAPLANMASI

Yıl 2009, Cilt: 25 Sayı: 1, 197 - 207, 01.02.2009

Musa Yiğit Mehmet Emin Korkmaz Mustafa Günay B. Şarer

Öz

Bu çalışmada 234-238U ve 231,233Pa çekirdeklerinin fisyon tesir kesitleri hesaplandı. Hesaplamalar 1-20 MeV gelme enerjili nötronlarla gerçekleştirildi. Hesaplamalarda ALICE-ASH ve CEM95 bilgisayar programları kullanıldı. CEM95 ile yapılan hesaplamalarda her bir çekirdek için seviye yoğunluğu parametresinin (IFAM) tüm sistematikleri kullanıldı. ALICE-ASH ile yapılan hesaplamalarda RFRM (Rotation-Finite-Range Model) ve RLDM (Rotation-liquid-Drop Model) modelleri kullanıldı. Hesaplanan fisyon tesir kesitleri Deneysel Nükleer Reaksiyon Veri (Experimental Nuclear Reaction Data-EXFOR) kütüphanesinden elde edilen deneysel değerlerle karşılaştırıldı [1].

Anahtar Kelimeler

Tesir kesiti, Fisyon engeli, Seviye yoğunluğu parametresi, Çığ eksiton modeli

THE CALCULATIONS OF (n,f) CROSS SECTIONS OF 234-238U AND 231,233Pa NUCLEI

Öz

In this study, cross section of 234-238U and 231,233Pa have been calculated. Calculations have been studied by 1-20 MeV incident energy neutrons. ALICE-ASH and CEM95 computer programs was used for calculations. In CEM95 calculations, all sistematics of level density parameters (IFAM) was used for each of nuclei. In ALICE-ASH calculations, RFRM (Rotation-Finite-Range Model) and RLDM (Rotation-liquid-Drop Model) was used. The calculated fission cross section was compared with the experimental data taken from the Experimental Nuclear Reaction Data (EXFOR) [1].

Anahtar Kelimeler

Cross section, Fission barrier, Level density parameter, Cascade exciton model

Kaynakça

• Experimental Nuclear Reaction Data, http://www.nndc.bnl.gov/exfor/exfor00.htm, 2008.
• Broeders C.H.M., Konobeyev A.Yu., Korovin A.Yu., Lunev V.P., Blann M., ALICE/ASH-Pre-compound and Evaporation Model Code System for Calculation of Excitation Functions, Energy and Angular Disributions of Emitted Particles in Nuclear Reactions at Intermediate Energies, Forschungszentrum Karlsruhe in der Helmoltz-Gemeinschaft, Wissenschaftliche Berichte, FZKA 7183, 2006.
• Mashnik S.G., Code CEM95, Bogoliubov Laboratory of Theoritical Physics, Joint Institute for nuclear research, Moskow, 1995.
• Weisskopf V.F., Ewing D.H., On the yield of nuclear reactions with heavy elements, Phys. Rev., 57, 472, 1940.
• Bohr N., Wheeler J.A., The mechanism of nuclear fission, Phys. Rev., 56, 426, 1939.
• Iljinov A.S., Mebel M.V., Bianchi N., De Sanctis E., Guardalo C., Lucherini V., Muccifora V., Polli E., Reolon A.R., Rossi P., Phenomenological statistical analysis of level densities, decay widths and lifetimes of excited nuclei, Nucl. Phys., A543, 517, 1992.
• Cameron A.G.W., Nuclear Radiation Widths, Can. J. Phys., 35, 1957.
• Dostrovsky I., Fraenkel Z., Friedlander G., Monte Carlo Calculations of Nuclear Evaporation Processes. III. Application to Low-Energy Reactions, Phys. Rev., 116, 683, 1959.
• Blann M., Bibplinghoff J., Code ALICE/LIVERMORE 82, Livermore Lawrence Laboratory, UCID-19614, 1982.
• Blann M., Code ALICE/85/300, Livermore Lawrence Laboratory, UCID-20169, 1984.
• Blann M., International Center for Theoretical Physics Workshop on Applied Nuclear theory and Nuclear Model Calculations for Nuclear Technology Applications, Italy, 1988.
• Blann M., ALICE 87 (Livermore) Precompound Nuclear Model Code, 1988.
• Sierk A.J., Macroscopic model of rotating nuclei, Phys. Rev., 33, 2039, 1986.
• Cohen S., Plasil F., Swiatecki W.J., Equilibrium Configurations of rotating Charged or Graviting Liquid Masses with Surface Tension, Ann. of Phys., 82, 557, 1974.
• Mustafa M.G., Baisden, P.A., Chandra H., Equilibrium shapes and fission barriers of rotating nuclei with a macroscopic two center model, Phys. Rev. 25, 2524, 1982.