II-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 55 (2022)

RIKEN Accel. Prog. Rep. 55 (2022)

Analysis of 48 Cr(p, n) reaction in inverse kinematics
M. Sasano,∗1 J. Gao,∗1,∗3 L. Stuhl,∗9,∗22 Y. Hirai,∗4 T. Wakasa,∗4 D. S. Ahn,∗1 J. K. Ahn,∗13 H. Baba,∗1K. Chae,∗20 A. Chilug,∗5,∗1 K. Cook,∗15 Y. Fujino,∗7 N. Fukuda,∗1 B. Gao,∗19 S. Goto,∗4 I. S. Hahn,∗8,∗22
Y. Hamano,∗4 Z. Halász,∗9 T. Harada,∗10,∗1 S. Hong,∗20 S. Huang,∗1,∗3 N. Inabe,∗1 D. Inomoto,∗4 T. Isobe,∗1H. Kasahara,∗4 D. Kim,∗8 T. Kobayashi,∗14,∗1 Y. Kondo,∗15,∗1 Z. Korkulu,∗1 A. Krasznahorkai,∗9 H. Miki,∗15K. Miki,∗14,∗1 S. Mitsumoto,∗4 M. Miwa,∗18,∗1 T. Motobayashi,∗1 T. Nakamura,∗15,∗1 M. Nishimura,∗1H. Oshiro,∗4 H. Otsu,∗1 V. Panin,∗1 S. Sakaguchi,∗4,∗1 D. Sakai,∗14 H. Sakai,∗1 S. Sakaki,∗4 H. Sato,∗1T. Shimada,∗15 Y. Shimizu,∗1 B. Sun,∗21 X. Sun,∗1,∗3 H. Suzuki,∗1 J. Tanaka,∗1 Y. Togano,∗7,∗1 T. Tomai,∗15,∗1T. Uesaka,∗1 Y. Utsuki,∗14 H. Wang,∗15 X. Xu,∗19 K. Yako,∗2 A. Yasuda,∗15 K. Yoneda,∗1 K. Yoshida,∗1Y. Yoshitome,∗15 and J. Zenihiro∗1
In this report, we present the progress of data analysis of the SAMURAI11 experiments performed at theRI Beam Factory of RIKEN Nishina Center in thespring of 2019. These experiments were conducted tomeasure the (p, n) reaction on N = Z unstable nuclei, 48 Cr and 64 Ge. Previously, in Refs. 1) and 2), wereported the experimental setup and the particle identiﬁcation (PID) analysis of the reaction residues using
the SAMURAI spectrometer,3) respectively. Herein,
we present the analysis of the data recorded using theparticle analyzer neutron detector of real-time acquisition (PANDORA)4) system.
The PANDORA neutron detector setup consists of
37 plastic scintillators and was placed on the left
and right sides of a liquid hydrogen target.5) The
neutron-gamma pulse-shape discrimination method
was employed to separate low-energy neutrons fromthe gamma-ray background. The neutron kinetic energies were deduced employing the time-of-ﬂight method,whereas the neutron scattering angles of the (p, n) reaction in the laboratory frame were determined fromthe scintillator bar positions.
Figure 1 shows the kinetic curve for the48
Cr(p, n)48 Mn reaction. Here, the reaction residue
47
Cr was selected from the PID analysis. 47 Cr is pro-Fig. 1. Two-dimensional plot of neutron kinetic energy vs.
neutron scattering angle in the laboratory frame. Solidand dashed curves represent the excitation energies andscattering angles in center-of-mass system of 48 Cr(p, n)reaction, respectively.

duced via the proton emission from the excited statesof 48 Mn populated by the (p, n) reaction. The proton
separation energy of 48 Mn is 2.05 MeV. We successfully identify a locus along the curve corresponding to4 MeV excitation energy of 48 Mn, above the separationenergy. Figure 1 shows events due to the backgroundin a low kinetic-energy region below 500 keV. A further
analysis is ongoing to substract the background.
We are grateful to the RIKEN accelerator staﬀ and
the CNS, University of Tokyo, for their continuous efforts to accomplish this stable beam acceleration.

∗1RIKEN Nishina CenterCenter for Nuclear Study, University of Tokyo∗3 School of Physics, Peking University∗4 Department of Physics, Kyushu University∗5 Horia Hulubei National Institute for R&D in Physics andNuclear Engineering∗7 Department of Physics, Rikkyo University∗8 Department of Physics, Ewha Womans University∗9 Institute for Nuclear Research, Hungarian Academy of Sciences∗10 Department of Physics, Toho University∗11 KVI - CART, University of Groningen∗12 GSI Helmholtzzentrum für Schwerionenforschung∗13 Department of Physics, Korea University∗14 Department of Physics, Tohoku University∗15 Department of Physics, Tokyo Institute of Technology∗16 Department of Physics, University of Tokyo∗18 Department of Physics, Saitama University∗19 Institute of Modern Physics, Chinese Academy of Sciences∗20 Department of Physics, Sungkyunkwan University∗21 School of Physics and Nuclear Engineering, Beihang University∗22 Center for Exotic Nuclear Studies, Institute for Basic Science∗2References
1) M. Sasano et al., RIKEN Accel. Prog. Rep. 53, 40(2019).
2) J. Gao et al., RIKEN Accel. Prog. Rep. 54, 14 (2020).
3) T. Kobayashi et al., Nucl. Instrum. Methods Phys. Res.
B 317, 294 (2013).
4) L. Stuhl et al., Nucl. Instrum. Methods Phys. Res. A866, 164 (2017).
5) M. Miwa et al., RIKEN Accel. Prog. Rep. 52, 149(2018).

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