2024年度核データ研究会/Symposium on Nuclear Data 2024

Measurement of residual nuclei with active-target TPCs and Si detectors/アクティブ標的TPCおよびSi半導体検出器を用いた残留核の測定

15 Nov 2024, 15:30

30m

熊取交流センター　すまいるズ　煉瓦館

Applications of Nuclear Data/核データの応用

Speaker

Takahiro/貴裕 Kawabata/川畑 (Osaka University/大阪大学)

Description

Time Projection Chambers (TPCs) and silicon (Si) semiconductor detectors are useful to examine residual nuclei in nuclear reaction.
We developed MAIKo and MAIKo+, which are TPC-based active target systems [1]. They enable tracking of low-energy charged particles over a large solid angle by using gas as both the detection medium and target. We utilize them to study triple-alpha reaction, which is one of the most important in nucleosynthesis in the universe. We inject a neutron beam into the MAIKo(+) active targets filled with a detection gas containing carbon, and measure 3 alpha particles emitted from excited states of residual carbon nuclei. A test measurement was conducted at the OKTAVIAN neutron beam facility in Osaka University, and it showed significant potential to measure residual nuclei in nuclear reactions [2].
We also developed a Si detector array SAKRA to detect decay particles from residual nuclei. It has particle-identification capabilities via pulse shape analysis. We demonstrated that SAKRA is capable to distinguish protons from alpha particles at E > 2 MeV and alpha particles from carbon nuclei at E > 5 MeV, and useful to examine decay processes of residual nuclei and to clarify their internal structures. We employed SAKRA to search for alpha cluster states in ${}^{24}$Mg [3].
In this talk, we will report the performance of MAIKo(+) and SAKRA, and present their application in our recent experimental works.

References
[1]. T. Furuno, T. Kawabata $\mathit{e}\mathit{t}\mathit{a}\mathit{l}$., “Performance test of the MAIKo active target”, Nucl. Instrum. Methods Phys. Res. A $\mathbf{908}$, 215 (2018).
[2]. T. Furuno $\mathit{e}\mathit{t}\mathit{a}\mathit{l}$., “Measurement of ${}^{12}$C($n,n^{\prime }$) reaction cross section to determine triple-alpha reaction rate in high-density environments”, EPJ Web of Conf. $\mathbf{260}$, 11010 (2022).
[3]. Y. Fujikawa, T. Kawabata $\mathit{e}\mathit{t}\mathit{a}\mathit{l}$., “Search for the 6$\alpha$ condensed state in ${}^{24}$Mg using the ${}^{12}$C + ${}^{12}$C scattering”, Phys. Lett. B $\mathbf{848}$, 138384 (2023).