Speaker
Description
The slow neutron capture process (s-process) and the intermediate process (i-process) play important roles in the nucleosynthesis of heavy elements from iron to uranium. As the dominant neutron source for the s- and i-processes, the reaction cross section of $^{13}$C(α,n)$^{16}$O reaction in the Gamow window(E$_{c.m.}$=140-500keV) is critical. Limited by the cosmic-rat and nature backgrounds, direct measurement of the extremely low reaction cross section in the Gamow window is very challenging.
The Jinping Underground Laboratory Nuclear Astrophysics (JUNA) team measured the $^{13}$C(α,n)$^{16}$O reaction cross section directly in the Gamow window with a high-current accelerator in China Jinping Underground Laboratory(CJPL).
While nearly all the cosmic-ray background is shielded in CJPL, radiations from uranium and thorium in the rocks of CJPL limit the detection sensibility. In this thesis, we introduce a method of background suppression technique by using the pulsed beam in CJPL. This method can increase the ratio of signal to background, suppress the influences of natural radiation in CJPL, improve the detection sensibility. It provides a new experimental technique for the future challenges of measuring the even reaction lower cross section.
