VI. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 54 (2021)

Nuclear Science and Transmutation Research Division
Nuclear Transmutation Data Research Group
Slow RI Data Team
1. Abstract

This team is in charge of the development of low-energy RI beams of long-lived fission fragments (LLFP) from the 238 U by meansof degrading the energy of beams produced by the BigRIPS fragment separator.

2. Major Research Subjects

Studies of the slowing down and purification of RI beams are the main subjects of the team. Developments of devices used forthe slowing down of RI beams are also an important subject.
(1) Study and development of the slowed-down methods for LLFP.
(2) Development of the devices used for the slowing down.
(3) Operation of the BigRIPS separator and supply the low energy LLFP beam to the experiment in which the cross sections ofLLFP are measured at the low energy.
(4) Development of the framework to seamlessly handle device, detector, DAQ, and analysis for the easy control of the complicate
slowed-down RI beam production and its development.

3. Summary of Research Activity

A new OEDO beam line, designed for the slowed-down RI beams, was constructed under the collaboration with CNS, the University of Tokyo. Our group was responsible for the construction of the infrastructure such as the cooling water and the electricalequipment, and the movement and alignment of existing vacuum chambers, quadrupole magnets. The power supply for the Superconducting Triplet Quadrupoles (STQ) was made, which had a stability also under the low current condition.
Slowed-down 93 Zr beams with 20 or 50 MeV/nucleon were successfully developed at June 2016 for the first time. The methods
to obtain the narrow energy, position, and angle distribution were developed. The methods of the energy adjustment and the particle
identification at 50 MeV/nucleon were developed. The 93 Zr and 107 Pd beams with 50 MeV/nucleon were produced for the nucleartransmutation experiments using proton or deuteron targets at October 2016. The commissioning experiment of the OEDO beamline was successfully performed at June 2017. The first transmutation experiments using OEDO beam line were performed with 93 Zr,
107
Pd, and 79 Se around 20 MeV/nucleon.
With our developments, the slowed-down RI beams became ready for the transmutation experiments. On the other hand, theprocedure to make the slowed-down RI beams became highly specialized. In order to easily produce the slowed-down RI beam, theframework is under the development to seamlessly handle the device, detector, DAQ, and analysis. The procedure of the RI-beamenergy control was implemented in the web application.

Members
Team Leader
Toshiyuki SUMIKAMA
Student Trainees
SungHan BAE (Seoul Nat’l Univ.)
Hiroya FUKUDA (Kyushu Univ.)

Misaki SAITSU (Kyushu Univ.)

List of Publications & Presentations
Publications[Original Papers]
T. Sumikama, D. S. Ahn, N. Fukuda, Y. Shimizu, H. Suzuki, H. Takeda, H. Wang, K. Yoshida, J. Amano, N. Chiga, K. Chikaato,
A. Hirayama, N. Inabe, S. Kawase, S. Kubono, M. Matsushita, S. Michimasa, K. Nakano, H. Otsu, and H. Sakurai, “Energy-control
and novel particle-identification methods combined with range in a multi-sampling ionization chamber for experiments using sloweddown RI beams,” Nucl. Instrum. Methods Phys. Res. A 986, 164687 (2021).
K. Nakano, Y. Watanabe, S. Kawase, H. Wang, H. Otsu, H. Sakurai, N. Chiga, J. Suwa, T. Sumikama, S. Takeuchi, T. Nakamura,
K. Chikaato, M. Takechi, S. Koyama, D. S. Ahn, H. Baba, S. Chen, M. L. Cortes, P. Doornenbal, N. Fukuda, A. Hirayama, R. Hosoda,T. Isobe, S. Kawakami, Y. Kondo, S. Kubono, Y. Maeda, S. Masuoka, S. Michimasa, I. Murray, R. Nakajima, M. Niikura, T. Ozaki,
A. Saito, T. Saito, H. Sato, Y. Shimizu, S. Shimoura, Y. Soudo, P. -A. Söderström, X. Sun, D. Suzuki, H. Suzuki, H. Takeda, Y. Togano,
T. Tomai, H. Yamada, M. Yasuda, and K. Yoshida, “Isotope-production cross sections of residual nuclei in proton- and deuteron-induced
reactions on 93 Zr at 50 MeV/nucleon,” EPJ Web Conf. 239, 20006 (2020).
H. Wang, H. Otsu, H. Sakurai, D. S. Ahn, M. Aikawa, T. Ando, S. Araki, S. Chen, N. Chiga, P. Doornenbal, N. Fukuda, T. Isobe,S. Kawakami, S. Kawase, T. Kin, Y. Kondo, S. Koyama, S. Kubono, Y. Maeda, A. Makinaga, M. Matsushita, T. Matsuzaki, S. Michimasa, S. Momiyama, S. Nagamine, T. Nakamura, K. Nakano, M. Niikura, T. Ozaki, A. Saito, T. Saito, Y. Shiga, M. Shikata, Y. Shimizu,- 250 -VI. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 54 (2021)

S. Shimoura, T. Sumikama, P. -A. Söderstrom, H. Suzuki, H. Takeda, S. Takeuchi, R. Taniuchi, Y. Togano, J. Tsubota, M. Uesaka,
Y. Watanabe, Y. Watanabe, K. Wimmer, T. Yamamoto, and K. Yoshida, “Spallation reaction study for long-lived fission products innuclear waste,” EPJ Web Conf. 239, 06003 (2020).
J. Ha, T. Sumikama, F. Browne, N. Hinohara, A. M. Bruce, S. Choi, I. Nishizuka, S. Nishimura, P. Doornenbal, G. Lorusso,
P. -A. Söderström, H. Watanabe, R. Daido, Z. Patel, S. Rice, L. Sinclair, J. Wu, Z. Y. Xu, A. Yagi, H. Baba, N. Chiga, R. Carroll,F. Didierjean, Y. Fang, N. Fukuda, G. Gey, E. Ideguchi, N. Inabe, T. Isobe, D. Kameda, I. Kojouharov, N. Kurz, T. Kubo, S. Lalkovski,
Z. Li, R. Lozeva, H. Nishibata, A. Odahara, Zs. Podolyák, P. H. Regan, O. J. Roberts, H. Sakurai, H. Schaﬀner, G. S. Simpson,
H. Suzuki, H. Takeda, M. Tanaka, J. Taprogge, V. Werner, and O. Wieland, “Shape evolution of neutron-rich 106, 108, 110 Mo isotopes inthe triaxial degree of freedom,” Phys. Rev. C 101, 044311 (2020).
T. Sumikama, N. Fukuda, N. Inabe, D. Kameda, T. Kubo, Y. Shimizu, H. Suzuki, H. Takeda, K. Yoshida, H. Baba, F. Browne, A. M. Bruce,
R. Carroll, N. Chiga, R. Daido, F. Didierjean, P. Doornenba, Y. Fang, G. Gey, E. Ideguchi, T. Isobe, S. Lalkovski, Z. Li, G. Lorusso,
R. Lozeva, H. Nishibata, S. Nishimura, I. Nishizuka, A. Odahara, Z. Patel, Zs. Podolyák, P. H. Regan, S. Rice, O. J. Roberts, H. Sakurai,
G. S. Simpson, L. Sinclair, P. -A. Söderström, M. Tanaka, J. Taprogge, H. Watanabe, V. Werner, O. Wieland, J. Wu, Z. Y. Xu, andA. Yagi, “Observation of new neutron-rich isotopes in the vicinity of 110 Zr,” Phys. Rev. C 103, 014614 (2021).

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