Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 52 (2019)

Activation cross sections of deuteron-induced reactions on niobium
up to 24 MeV†
M. Aikawa,∗1,∗2 Y. Komori,∗2 and H. Haba∗2†∗1∗2Condensed from the article in Nucl. Instrum. Methods Phys.
Res. B 436, 217 (2018)
Faculty of Science, Hokkaido University
RIKEN Nishina Center- 197 -Ditroi 2000
Tarkanyi 2007
Avrigeanu 2013
TENDL2017
This work

Cross section (mb)20015093Nb(d,x)93mMo

100
50005101520

Energy (MeV)

Fig. 1. Excitation function of the 93 Nb(d, 2n)93m Mo reaction.

250

Dmitriev 1983
Ditroi 2016
This work93m

Mo

Physical yield (MBq/µAh)

One of the potential radioisotopes for nuclear
medicine is 93m Mo.1) Several reactions to produce
93m
Mo were studied, for example, proton- anddeuteron-induced reactions on Nb, α-induced reactions
on Zr, and 7 Li-induced reactions on Y. In this paper, we focus on the deuteron-induced reactions onNb because the cross sections of these reactions areabout four times larger than those of the protoninduced reactions.2) Four experimental data sets upto 50 MeV2–5) were found in a literature survey, andthey were scattered over several tens of mb at apeak of around 17 MeV. Therefore, we performed
an experiment to measure the cross sections of the93
Nb(d, 2n)93m Mo reaction.
We used standard methods such as the stackedfoil activation method and oﬀ-line γ-ray spectrometry.
The stacked target of the experiment was composedof thin metallic foils of 93 Nb (27.11 mg/cm2 , 99.9%
purity, Nilaco Corp., Japan) and nat Ti (9.13 mg/cm2 ,99.6% purity, Nilaco Corp., Japan). The nat Ti foils
were used to monitor the beam parameters. The target was irradiated by a 23.6-MeV deuteron beam at
the AVF cyclotron of the RIKEN RI Beam Factory.
The incident beam energy was measured by the timeof-ﬂight method using a plastic scintillator monitor.6)
The irradiation lasted for 30 min with an average intensity of 200.3 nA, which was measured using a Faraday cup. The energy degradation of the beam in thestacked target was calculated using the SRIM code.7)
The beam parameters and the target thicknesses wereassessed by the nat Ti(d, x)48 V monitor reaction. The
γ lines from the foils were measured by using a highresolution HPGe detector.
The 263.049-keV γ line (Iγ = 57.4%) from the93m
Mo IT decay (T1/2 = 6.85 h) was measured after acooling time of about 10 h. The excitation functionof the 93 Nb(d, 2n)93m Mo reaction was derived fromthe measurement. The result is shown in Fig. 1 together with the earlier experimental data3–5) and theTENDL-2017 data.8) Our result shows good agreementwith the other experimental data in the entire energyregion. The theoretical calculation overestimates theexperimental data.
The physical yield of 93m Mo from the 93 Nb(d,2n)93m Mo reaction was calculated from the excitation
function using the spline ﬁtting shown in Fig. 1 and thestopping power calculated by the SRIM code.7) The re-200
150
1005000510152025

Energy (MeV)

Fig. 2. Physical yield of 93m Mo.

sult, together with the other experimental data,2,9) isshown in Fig. 2. Our result is consistent with the twodata studied earlier.2,9)References
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