Competition between the compound and the pre-compound emission processes in α-induced reactions at near astrophysical energy to well above it

8th European Summer School on Experimental Nuclear Astrophysics (Santa Tecla School)

物理学;天文学

Sharma, Manoj Kumar^1 ; Sharma, Vijay Raj^2 ; Yadav, Abhiskek^3 ; Singh, Pushpendra P.^4 ; Singh, B.P.^2 ; Prasad, R.^2

Department of Physics, Sri Varsheny College, Aligarh, India^1

Department of Physics, Aligarh Muslsim Uinversity, Aligarh, India^2

Interuniversity Accelerator Centre, New Delhi, India^3

Department of Physics, IIT, Ropar, India^4

关键词: Activation techniques;    Alpha induced reactions;    Analysis of data;    Astrophysical energies;    Emission calculation;    Excitation function;    Gamma ray spectrometry;    Geometry dependent hybrid models;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/703/1/012025/pdf
DOI  :  10.1088/1742-6596/703/1/012025

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

The study of pre-compound emission in α-induced reactions, particularly at the low incident energies, is of considerable interest as the pre-compound emission is more likely to occur at higher energies. With a view to study the competition between the compound and the pre-compound emission processes in α-induced reactions at different energies and with different targets, a systematics for neutron emission channels in targets51V,55Mn,93Nb,121, 123Sb and141Pr at energy ranging from astrophysical interest to well above it, has been developed. The off-line γ-ray-spectrometry based activation technique has been adopted to measure the excitation functions. The experimental excitation functions have been analysed within the framework of the compound nucleus mechanism based on the Weisskopf-Ewing model and the pre-compound emission calculations based on the geometry dependent hybrid model. The analysis of the data shows that experimental excitation functions could be reproduced only when the pre-compound emission, simulated theoretically, is taken into account. The strength of pre-compound emission process for each system has been obtained by deducing the pre-compound fraction. Analysis of data indicates that in α-induced reactions, the pre-compound emission process plays an important role, particularly at the low incident energies, where the pure compound nucleus process is likely to dominate.