Ⅳ. OPERATION RECORDS

RIKEN Accel. Prog. Rep. 56 (2023)
RIKEN
Accel. Prog. Rep. 56 (2023)

Fee-based activities performed by the RI application research groupA. Nambu,∗1 H. Haba,∗1 A. Yoshida,∗1 K. Watanabe,∗1 and T. Kambara∗1
This article summarizes the fee-based activities performed by the RI Application Research Group in 2022,
which include the distribution of radioisotopes (RIs)
and utilization of heavy-ion beams in the industry.
Since 2007, RIKEN has distributed RIs to users inJapan for a fee in collaboration with the Japan Radioisotope Association1) (JRIA). The nuclides include
65Zn (T1/2 = 244 d), 109 Cd (T1/2 = 463 d), 88 Y (T1/2= 107 d), 85 Sr (T1/2 = 65 d), and 67 Cu (T1/2 = 61.8 h)
produced in the RIKEN AVF cyclotron by the Nuclear
Chemistry Research Team of the RI Application Research Group.
According to a material transfer agreement (MTA)
drawn between JRIA and RIKEN, JRIA mediates thetransaction of RIs and distributes them to users. 65 Zn
and 109 Cd are delivered approximately two weeks after the acceptance of an order. 85 Sr, 88 Y, and 67 Cu,
which have short half-lives, are not stocked like 65 Zn
and 109 Cd; instead, they are produced in a scheduled
beamtime after an order is accepted. Therefore, they
are delivered after two or more months. Details regarding RIKEN RIs can be found on the online orderingsystem, J-RAM,2) of JRIA. In 2022, we delivered 5, 1,5, and 1 shipments of 65 Zn, 109 Cd, 85 Sr, and 67 Cu witha total activity of 17.7, 5, 11.7, and 10 MBq, respectively; there was no shipment of 88 Y. The 67 Cu delivery
was the second since the beginning of its distribution in
2018. The ﬁnal recipients of RIs included six universities, one research institute, and two private companies.
Figure 1 shows the yearly trends in the number of orders and amount of distributed RIs. Compared with2021, the amounts of distributed 109 Cd and 67 Cu increased, and those of 65 Zn, 88 Y, and 85 Sr decreased.
The amount of 85 Sr distributed in 2022 was still thesecond highest since the beginning of its distribution.
The number of orders for 65 Zn in 2022 increased again
and reached its highest in the last eight years.
In addition, we also provide 211 At (T1/2 = 7.2 h)through an MTA drawn between Osaka University andRIKEN, and among University of Tokyo, Saitama Medical University, and RIKEN. 211 At is delivered to theuniversities directly from RIKEN due to its short halflife. In 2022, we delivered a total of 5.4 GBq of 211 Atto Osaka University in 11 shipments, and 250 MBq toUniversity of Tokyo in 5 shipments.
The Industrial Application Research Team of the RI
Application Research Group promotes the utilization ofheavy-ion beams in the industry. The RIKEN Nishina
Center allows the use of the AVF cyclotron, RILAC2,and RIKEN Ring Cyclotron (RRC) by private companies in Japan for a fee.3) Currently, the main users
include semiconductor companies that irradiate space∗1

RIKEN Nishina CenterFig. 1. Number of orders (upper) and amount (lower) of RIs
distributed annually from 2007 to 2022. The distributionof 88 Y, 85 Sr, and 67 Cu started in 2010, 2015, and 2018,
respectively.

use semiconductor devices with 40 Ar, 84 Kr, or 136 Xeions from the RRC to simulate single-event eﬀects dueto the heavy-ion components of cosmic radiation.
The proposals for beam utilization are reviewed bya program advisory committee dedicated to industrialuse (In-PAC).
In January 2022, In-PAC reviewed and approved two
proposals via e-mail. In July, In-PAC held its 19thmeeting, where it reviewed and approved seven proposals, including four new proposals.
In 2022, seven companies executed 25 fee-based
beamtimes, 14 of which used a 84 Kr beam with a total
beamtime of 234 hours, 9 utilized an 40 Ar beam witha total beamtime of 129 hours, and 2 utilized a 136 Xebeam with a total beam time of 20 hours.
References
1) http://www.jrias.or.jp/ (Japanese),
http://www.jrias.or.jp/e/ (English).
2) https://j-ram.org/ (Japanese).
3) http://ribf.riken.jp/sisetu-kyoyo/HIbeam/ (Japanese).

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