Subjects: Nuclear Science and Technology >> Radiation Physics and Technology submitted time 2024-04-10
LIN Shen
SONG Luyang
SU Jun
CHEN Xin
SHEN Zhilin
ZHANG Hao
SHENG Yaode
ZHANG Liyong
HE Jianjun
CHEN Size
SHEN Yangping
JIN Shilun
LU Fei
XIAO Dan
ZHANG Yong
NAN Wei
JIANG Yuchen
ZHANG Yuqiang
ZHANG Yang
TIAN Junwen
Abstract： In thermonuclear reactions of nuclear astrophysical interest, some can produce short-lived products that emit positrons. The positrons emitted by these products will annihilate with electrons in the target and then produce a pair of 511 keV γ-rays, which can be used to determine the reaction yield and calculate the cross-section as well as the astrophysical S-factor. Recently, it has been found that the spatial coincidence measurements can be performed basing on the opposite direction of the 511 keV-511 keV γ-ray pair, which can reduce the natural background and enables the in situ measurement of the reaction yield using activity method. In this paper, based on the recently developed large modular BGO detector array LAMBDA-II, this method has been investigated and validated in the ground laboratory, which provides good basis for further application of this method in the nuclear astrophysical investigations in the future.
Peer Review Status:
Awaiting Review
Subjects: Physics >> Nuclear Physics submitted time 2024-03-11
Abstract： Fusion triple product represents a crucial parameter for evaluating the potential of self-sustained fusion nuclear reactions. It employs the product of three physical properties: the fuel nuclei number density ($n$), plasma confinement time ($τ_ mathrm{E}$) and fuel temperature ($T$) to establish a condition for assessing the feasibility of achieving self-sustained nuclear fusion. This study considers a fusion reaction system using $^{6}$Li-D as nuclear fuel, neglects cyclotron radiation, incorporates the impact of relativistic effects on bremsstrahlung radiation and the impact of recycled energy on the energy gain factor $Q$. Based on this foundation, the minimum triple product ($n_ mathrm{i}Tτ_ mathrm{E}$= SI{4.9e23}{ per cubic meter kilo electronvolt second}) is calculated for the $^{6}$Li-D reaction to yield energy gain of Q=1. These results show that although the $^{6}$Li-D fusion reaction can achieve a positive energy gain but the condition required for the $^6$Li-D fusion reaction is more difficult than the D-T fusion reaction.
Subjects: Physics >> Nuclear Physics submitted time 2023-09-04 Cooperative journals: 《核技术》
Abstract： Supernovae are the most gorgeous fireworks that people can observe in the universe. Their explosion can produce a maximum luminosity 10 billion times that of the Sun, helping scientists see farther. Type Ia supernovae can be used as a standard candle to facilitate measurement of the distance between galaxies in the universe. A supernova explosion will also propel a large number of heavy elements into interstellar space, which is a major driving force for the chemical evolution of galaxies. In addition, supernovae are crucial to the origin of elements in the Milky Way, the formation of the structure of the solar system, and the evolution of life on the Earth. The study of supernovae will further enrich our understanding of the universe and help us solve the mysteries of the expansion of the universe, the generation of heavy elements, and the origin of life. At present, scientists predict that the next supernova will explode at any time, and preparations are in progress for observing the coming supernova.
Hits
Hits
Downloads
Comment
YES