RIKEN Nishina Center for Accelerator-Based Science Next-Generation Heavy-Ion Accelerator Systems Development Team

Team Leader: Hiroshi Imao (D.Sc.)

Japanese Page

Research Summary

We are advancing the RIBF Upgrade Program to further increase beam intensity at the RI Beam Factory (RIBF), focusing on the development of the Charge Stripper Ring (CSR). The CSR is a unique accelerator in which an ion beam circulates in the ring while repeatedly undergoing charge exchange until the desired charge state is reached. Our work covers the simultaneous and stable circulation of multi-charge-state beams, gas charge-exchange schemes, and beam control techniques that exploit charge exchange. We also explore a future extension of the CSR concept toward a heavy-ion internal-target ring, referred to as “Chreostron.”

Main Research Fields

Interdisciplinary Science & Engineering

Related Research Fields

Engineering
Mathematical & Physical Sciences

Keywords

High-intensity heavy-ion beams
Charge stripper ring
Multi-charge-state beams
Gas stripper
Beam cooling

Selected Publications

1. Imao H.:
"A Charge Stripper Ring at RIKEN RI Beam Factory"
Proc. of HIAT2025, East Lansing, USA, FRX01, 282-287, (2025).
2. Imao H.:
"Status update of the Charge Stripper Rings project"
Journal of Instrumentation 18, P03028 (2023).
3. Imao H.:
"The Present Status and Future Plan with Charge Stripper Ring at RIKEN RIBF"
Proc. of the 13th International Particle Accelerator Conference (IPAC’22), pp. 796–801 (2022).
4. Imao H.:
"Charge Stripper Ring for RIKEN RI Beam Factory"
Journal of Instrumentation 15, P12036 (2020).
5. Imao H., Kamigaito O., Oyamada K., Sakamoto N., Watanabe T., Watanabe Y., Yamada K.:
"Non-Evaporative Getter-Based Differential Pumping System for SRILAC at RIBF"
Proc. of the 19th International Conference on RF Superconductivity (SRF’19), pp. 419–423 (2019).
6. Imao H.:
"Development of Gas Stripper at RIBF"
Proc. of the 9th International Particle Accelerator Conference (IPAC’18), pp. 41–46 (2018).
7. Imao H., Kamigaito O., Okuno H., Fukunishi N., Sakamoto N., Yamada K., Yano Y.:
"Charge Stripper Ring for Cyclotron Cascade"
Proc. of the 21st International Conference on Cyclotrons and Their Applications (CYC’16), pp. 155–159 (2016).
8. Imao H., Okuno H., Kuboki H., Kamigaito O., Hasebe H., Fukunishi N., Watanabe T., Fujimaki M., Watanabe Y., Maie T., Kase M., Yano Y.
"Charge-Stripping System for a 238U Ion Beam with Recirculating He Gas"
Journal of Radioanalytical and Nuclear Chemistry 299, 941–944 (2014).
9. Imao H., Okuno H., Kuboki H., Kamigaito O., Hasebe H., Fukunishi N., Watanabe Y., Fujimaki M., Maie T., Dantsuka T., Kumagai K., Yamada K., Watanabe T., Kase M., Yano Y.:
"R&D of Helium Gas Stripper for Intense Uranium Beams"
Proc. of the 13th International Conference on Cyclotrons and Their Applications (CYC’13), Vancouver, BC, Canada, TU3PB03, p. 265 (2013).
10. Imao H., Okuno H., Kuboki H., Yokouchi S., Fukunishi N., Kamigaito O., Hasebe H., Watanabe T., Watanabe Y., Kase M., Yano Y.:
"Charge Stripping of a 238U Ion Beam by a Helium Gas Stripper"
Physical Review ST Accelerators and Beams 15, 123501 (2012).

Lab Members

Principal investigator

Hiroshi Imao: Team Leader

Contact Information

2-1 Hirosawa,
Wako, Saitama
351-0198, Japan
Email: imao@riken.jp