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

RIKEN Accel. Prog. Rep. 56 (2023)

Production cross sections of 52g Mn in α-particle-induced reactions onnat †V
G. Damdinsuren,∗1,∗2 M. Aikawa,∗1,∗2,∗3 Kh. Tegshjargal,∗4 N. Erdene,∗4 S. Ebata,∗5,∗2 and H. Haba∗2
Manganese-52 has the longer-lived ground stateMn (T1/2 = 5.6 d, ε + β + : 100%) and the shorterlived excited state 52m Mn (T1/2 = 21.1 min, IT: 1.78%,ε + β + : 98.22%). The decay processes of 52g Mn
are electron capture (70.6%) and positron emission(29.4%, ⟨Eβ + ⟩ = 242 keV).1) The positrons emitted
from the decay of 52g Mn can be used for PositronEmission Tomography (PET).2) The direct routes to
produce 52g Mn involve charged-particle-induced reactions on chromium and vanadium. Whereas, the indirect route involves the internal transition of 52m Mn
co-produced simultaneously in the reactions. This
study, we focused on the α-particle-induced reaction
on nat V. Eleven experimental cross section data of
the nat V(α, x)52g Mn reactions were found in the EXFOR library.3) However, their data are largely scattered. Therefore, we measured the excitation functionof the nat V(α, x)52g Mn reaction up to 50 MeV. The obtained cross sections were compared with the literature
data and theoretical calculation in the TENDL-2019
library.4)
The stacked-foil activation technique and highresolution γ-ray spectrometry were used to measure
the cross sections. Pure metallic foils of nat V (25µm thick, 99% purity), nat Ti (5-µm thick, 99.6% purity), and 27 Al (5-µm thick, >99% purity) were purchased from Nilaco Corp., Japan, and used for thestacked target. The nat Ti foils were interleaved for thenatTi(α, x)51 Cr monitor reaction. The 27 Al foils wereused to catch recoiled products from the nat V and nat Ti
foils. The average target thicknesses were derived fromthe measured size and weight of the original foils. Derived average thicknesses of nat V, nat Ti, and 27 Al foils
were 20.4, 2.24, and 1.22 mg/cm2 , respectively. Theoriginal foils were cut into a size of 8 × 8 mm. Elevensets of V-Al-Ti-Ti-Al foils were stacked into a target
holder, which served as a Faraday cup.
The stacked target was irradiated with an α-particle
beam for 30 min. The primary beam energy was measured by the time-of-ﬂight method.5) The measured
beam energy was 50.6 ± 0.2 MeV. Consequently, theenergy degradation in the stacked target was calcu-lated using stopping powers obtained from the SRIM
code.6) The average beam intensity measured using theFaraday cup was 194 nA.
γ rays emitted from each irradiated foil were measured by a high-resolution HPGe detector (ORTECGEM-25185-P), which was calibrated with a multiple
gamma-ray emitting point source. The spectra wereanalyzed using dedicated software (SEIKO EG&GGamma Studio). Each nat V foil with the following
27
Al catcher foil was measured several times. The distance between the detector and foils was arranged toensure a dead time of less than 3%.
The cross sections of the nat Ti(α, x)51 Cr monitor reaction were derived and used to assess the beam parameters and target thicknesses. The measurement ofthe γ line at 320.08 keV (Iγ = 9.91%) from the decayof 51 Cr (T1/2 = 27.7025 d) was performed following acooling time of 3 days. Only the Ti foils at the beam
downstream of each Ti-Ti foil pair in the stack wereused for cross section deduction because the compensation of recoiled 51 Cr was expected. The dead time
during the measurements was maintained at less than1%. Subsequently, the derived cross sections were compared with the IAEA-recommended values7) and foundto be consistent with each other. We adopted the measured beam parameters and target thicknesses without
any corrections for data analyses.
The cross sections of the nat V(α, x)52g Mn reaction
were derived. The γ line at 935.544 keV (Iγ = 94.5%)
from the decay of 52g Mn was measured following a cooling time of 17 d. During the cooling time, the excitedstate 52m Mn completely decayed to the ground state
52g
Mn or the stable nuclide 52 Cr. The cumulative cross52g

†
∗1
∗2
∗3
∗4
∗5

400

natV(α,x)52gMn(cum)350

Cross section [mb]300

Condensed from the article in Appl. Radiat. Isot. 184,110204 (2022)
Graduate School of Biomedical Science and Engineering,
Hokkaido University
RIKEN Nishina Center
Faculty of Science, Hokkaido University
School of Engineering and Applied Sciences, National University of Mongolia
Graduate School of Science and Engineering, Saitama University- 169 -◐

250200150
1005001015This work
Bowman (1969)
Dmitriev (1969)
Michel (1982)
Rama (1987)
Levkovski (1991)
Singh (1993)
Sonzogni (1993)
Ismail (1993)
Singh (1995)
Chowdhury (1995)
Bindu (1998)
TENDL-2019

2025◐◐ ◐30◐◐◐◐◐◐35404550

Energy [MeV]Fig. 1. Excitation functions of the nat V(α, x)52g Mn reaction.

Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 56 (2023)

sections could be derived from the measured net countsof the γ line. The excitation functions are shown inFig. 1 along with the literature data and TENDL2019 values.4) The measured cross sections exhibiteda smooth curve and agreement with part of the previous experimental data. However, the shape of theTENDL-2019 values was largely diﬀerent from the experimental data.
G. Damdinsuren was granted a scholarship by theM-JEED project (Mongolian-Japan Engineering Education Development Program, J11B16).
References
1) Y. Dong et al., Nucl. Data Sheets 128, 185 (2015).
2) F. Bianchi et al., Appl. Radiat. Isot. 166, 109329 (2020).
3) N. Otuka et al., Nucl. Data Sheets 120, 272 (2014).
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), (2014), p. 3566.
6) J. F. Ziegler et al., Nucl. Instrum. Methods Phys. Res.
B 268, 1818 (2010).
7) F. Tárkányi et al., IAEA-TECDOC-1211 (2007).

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