Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 53

Production cross sections of dysprosium-159 radioisotope from thedeuteron-induced reactions on terbium-159 up to 24 MeV†
D. Ichinkhorloo,∗1,∗2,∗3 M. Aikawa,∗1,∗3,∗4 Ts. Zolbadral,∗4,∗2,∗3 Y. Komori,∗3 and H. Haba∗3Dysprosium-159 (T1/2 = 144.4 d) can be used
to determine of bone mineral density.1) The dysprosium radionuclide can be produced by the chargedparticle-induced reactions on the monoisotopic elementterbium-159. In this work, the production cross sections of 157, 159 Dy and 160 Tb in the deuteron-induced
reactions on 159 Tb were studied. The results were compared with experimental data published previously2,3)
and TENDL-2017 data.4)
The experiment was performed at the RIKEN AVF
cyclotron. The stacked foil technique, the activation
method, and high-resolution γ-ray spectrometry wereused to determine the activation cross sections.
The stacked target consisted of 10 × 10 mm2 foils
cut from a large Tb foil (25 µmt, 25 × 50 mm2 , 99.9%
purity, Nilaco Corp., Japan) and two Ti foils (5 µmt,50×100 mm2 , 99.6% purity and 20 µm, 120×100 mm2 ,99.5% purity, Nilaco Corp., Japan). The sizes andweights of the large foils were measured to derive thethicknesses. The thicknesses of the Tb and two Ti foils
were found to be 20.56, 2.25, and 9.31 mg/cm2 , respectively. The Ti foils were interleaved to check the beam
parameters using the nat Ti(d, x)48 V monitor reaction.
The cut foils were stacked in a target holder, which
also served as a Faraday cup.
The deuteron beam was accelerated to 23.9 MeV using the RIKEN AVF cyclotron. The beam energy wasmeasured by the time-of-ﬂight method.5) The stackedtarget was irradiated by the beam for 60 min withan average intensity of 94.3 nA. The beam intensity
was measured using the Faraday cup. Energy degradation in the stacked target was calculated using SRIM
code.6)The γ-rays emitted from the irradiated foils weremeasured using a high-resolution high-purity germanium (HPGe) detector. The γ-ray spectra were analyzed using the software Gamma Studio (SEIKOEG&G). The γ line at 58.0 keV (Iγ = 2.27%) emittedwith the 159 Dy decay (T1/2 = 144.4 d) was measured
to derive the cross sections of the 159 Tb(d, 2n)159 Dy
reaction. The measurements were performed after acooling time of 94 days. The γ line had negligible interference with the x-ray of the lead shielding of thedetector, which could be conﬁrmed by the absence ofpeaks at the energy in the two foils at the downstream
†
∗1
∗2
∗3
∗4Fig. 1. Excitation function of the 159 Tb(d, 2n)159 Dy reaction.

of the beam. The self-absorption of the low-energy
γ line in the Tb foils was considered using the massattenuation coeﬃcient.
The cross sections derived from the corrected activities for 159 Dy production are presented with previous experimental data2,3) and TENDL-2017 data4) inFig. 1.
Our experimental data show a peak at approximately 14 MeV, which is consistent with other experimental data, while the amplitudes are substantialy
diﬀerent. The TENDL-2017 data slightly deviate fromours.
In summary, we performed an experiment to measure the excitation functions of deuteron-induced reactions on 159 Tb up to 24 MeV at the RIKEN AVF
cyclotron. The production cross sections of 157, 159 Dyand 160 Tb were determined. The results were compared with previously obtained experimental data andTENDL data.
This work was supported by JSPS KAKENHI Grant
Number 17K07004.
References
1) D. V. Rao et al., Med. Phys. 4, 109 (1977).
2) T. M. Duc et al., C. R. Acad. Sci. Ser. B 266, 100(1968).
3) F. Tárkányi et al., Nucl. Instrum. Methods Phys. Res.
B 316, 183 (2013).
4) A. J. Koning et al., Nucl. Data Sheets 155, 1 (2019).
5) T. Watanabe et al., Proc. 5th Int. Part. Accel. Conf.
(IPAC 2014), 3566 (2014).
6) J. F. Ziegler et al., SRIM: the Stopping and Range ofIons in Matter, http://www.srim.org .

Condensed from the article in Nucl. Instrum. Methods Phys.
Res. B 461, 102 (2019)
Faculty of Science, Hokkaido University
Nuclear Research Center, National University of Mongolia
Nishina Center for Accelerator-Based Science, RIKEN
Graduate School of Biomedical Science and Engineering,
Hokkaido University- 23 -