Ⅲ-3. Radiochemistry & Nuclear Chemistry
RIKEN
Accel. Prog. Rep. 56 (2023)

RIKEN Accel. Prog. Rep. 56 (2023)

Activation cross sections of 28 Mg via α-particle-induced reaction on27Al
M. Aikawa,∗1,∗2 H. Huang,∗3,∗2 G. Damdinsuren,∗3,∗2 S. Ebata,∗4,∗2 H. Haba,∗2 S. Takács,∗5,∗2 F. Ditrói,∗5,∗2and Z. Szücs∗5,∗2

∗1
∗2
∗3
∗4
∗5

mended values, the incident beam energy and thickness
of Al target foils were corrected within their uncertainties by +0.2 MeV and −1%, respectively. The othermeasured parameters were adopted without correction.
The corrected cross sections were consistent with therecommended values, indicating proper beam parameters and energy loss determination within the stack,as shown in Fig. 1.
The cross sections of the 27 Al(α, 3p)28 Mg reaction
were determined using the γ line at 1342 keV (Iγ =54%), which was emitted with the decay of 28 Mg (T1/2= 20.9 h). Figure 2 shows our preliminary result withthe earlier experimental data obtained from the EXFOR library2) and the TENDL-2021 theoretical values.6) The theoretical values are considerably lower
than the experimental data.
700

natTi(α,x)51Cr

Cross section (mb)

600

Faculty of Science, Hokkaido University
RIKEN Nishina Center
Graduate School of Biomedical Science and Engineering,
Hokkaido University
Graduate School of Science and Engineering, Saitama University
Institute for Nuclear Research (ATOMKI)- 165 -500

IAEA (2018)
This work

400
300
200
100
00102030

4050

α-particle energy (MeV)

Fig. 1. Cross sections of the nat Ti(α, x)51 Cr monitor reaction with the IAEA recommended values.5)

0.5
Cross section (mb)Magnesium-28 (T1/2 = 20.9 h) decays with emission of a β − particle and γ rays. This radionuclide can be used as a radiotracer in several applications.1) The promising production reaction of 28 Mg
is the α-particle-induced reaction on 27 Al targets.
Ten experimental studies on the cross sections of the27Al(α, 3p)28 Mg reaction were found in the EXFOR
library.2) However, the cross sections of the previous
studies are broadly scattered. Therefore, we performed
an experiment to obtain reliable cross sections of the27Al(α, 3p)28 Mg reaction.
An experiment using a 50.7-MeV α-particle beam
was conducted at the RIKEN AVF cyclotron employing the stacked-foil activation technique and highresolution γ-ray spectrometry.
Pure metallic foils of 27 Al (>99% purity, 50 and5 µm thick) and nat Ti (99.6% purity, 5 µm thick) werepurchased from Nilaco Corp., Japan. The 50- and 5µm Al foils were used as target and catcher foils, respectively. The Ti foil was used for the nat Ti(α, x)51 Cr
monitor reaction. The size and weight of all foils were
measured for the average thicknesses. The thicknessesof the Al target, Al catcher, and Ti monitor foils weredetermined as 13.2, 1.22, and 2.37 mg/cm2 , respectively. The foils were cut into a 10 × 10 mm size andstacked in a target holder that served as a Faradaycup.
The stacked target was irradiated for 30 min witha 50.7-MeV α-particle beam. The initial beam energy
was determined using the time-of-ﬂight method.3) The
average beam intensity measured using the Faraday
cup was obtained as 205 nA. The beam energy degradation in the stacked target was calculated using stopping powers obtained from the SRIM code.4) γ rays
emitted from the irradiated foils were measured using ahigh-purity germanium detector (ORTEC GEM30P470) and dedicated analysis software (SEIKO EG&GGamma Studio) without chemical separation.
The cross sections of the nat Ti(α, x)51 Cr monitor reaction were derived using the γ line at 320 keV (Iγ =9.91%) from the decay of 51 Cr (T1/2 = 27.7 d). The
derived cross sections were compared with the International Atomic Energy Agency recommended values.5)
For best agreement between the measured and recom-27Al(α,3p)28Mg

0.4

Nethaway (1958)
Martens (1970)
Nozaki (1975)
Probst (1976)
Rattan (1985)
Rattan (1986)
Karamyan (1992)
This work

0.3
0.2
0.1
0253035404550

α-particle energy (MeV)

Fig. 2. Measured cross sections of the 27 Al(α, 3p)28 Mg reaction with the literature data and the TENDL-2021
values.6)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 56 (2023)

References
1) N. P. van der Meulen et al., Appl. Radiat. Isot. 115,125 (2016).
2) N. Otuka et al., Nucl. Data Sheets 120, 272 (2014).
3) T. Watanabe et al., Proc. 5th Int. Part. Accel. Conf.
(IPAC2014), (2014), p. 3566.
4) J. F. Ziegler et al., Nucl. Instrum. Methods Phys. Res.
B 268, 1818 (2010).
5) A. Hermanne et al., Nucl. Data Sheets 148, 338 (2018).
6) A. J. Koning et al., Nucl. Data Sheets 155, 1 (2019).

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