Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 48 (2015)

Measurements of alpha-induced cross section for 48Cr and 49Cr up to50 MeV
H. Kikunaga,∗1,∗2 M. Murakami,∗3,∗2 Y. Komori,∗2 and H. Haba∗2

∗1
∗2
∗3

Research Center for Electron Photon Science, Tohoku University
RIKEN Nishina Center
Graduate School of Science and Technology, Niigata University96F

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lated values with the Talys code reproduce the experimental values of 48 Cr and 49 Cr with a reasonable accuracy although each peak position of the excitation
functions is deviated slightly.

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Fig. 1. A γ-ray spectrum of a Ti foil sample at an eﬀectiveenergy of around 50 MeV.

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Chromium is one of the essential trace elements insome animals but it also can be toxic in high concentrations. Understanding the behavior of chromium inanimals, plants, and the environment is important andinﬂuential on the various ﬁelds such as biological sciences.
The radioactive tracer technique has been widely
recognized as a powerful tool for behavior analysis ofelements in trace amounts. The isotopes 48 Cr (T1/2= 21.6 h), 49 Cr (T1/2 = 42.3 m), and 51 Cr (T1/2 =27.7 d) have potential as tracers because of their suitable half-lives. In this work, the cross sections for thereactions nat Ti(α, X)48 Cr and nat Ti(α, X)49 Cr up to
50 MeV were measured to produce these isotopes eﬃciently.
The excitation functions of these reactions were measured by the stacked-foil technique. The target stack
containing 20 natural Ti foils (99.5% pure) with thickness of 20 and 40 μm were irradiated with a α-particle
beam delivered from the RIKEN K70 AVF Cyclotronfor 30 min. The cyclotron was operated at a beam energy of 50.4 MeV, which was conﬁrmed by TOF measurement, with a mean current of around 0.4 μA.
After the irradiation, the target foils were enclosed
in a polyethylene ﬁlm separately and were subjectedto γ-ray spectrometry using a high-purity germanium
detector. The incident beam energy and ﬂux were determined by activation of the monitor foil techniqueusing the nat Ti(α, X)51 Cr reaction. The reference data
were obtained from the IAEA Reference Data1) . Theenergy loss in each foil was calculated using the TRIM
code2) .
A γ-ray spectrum of a Ti foil sample at an eﬀectiveenergy of around 50 MeV is shown in Fig. 1. The γpeaks of scandium, vanadium, and chromium are observed in the spectrum. During the tracer preparation,
it is necessary to separate chromium from titanium andthe other elements.
The cross sections for the nat Ti(α, X)48 Cr andnatTi(α, X)49 Cr reaction obtained in this work areshown in Fig. 2. For comparison, the earlier experimental data3–6) of the nat Ti(α, X)48 Cr reaction andthe values calculated using the Talys 1.6 code7) withdefault parameters are included in Fig. 1. The crosssections of 48 Cr obtained in this work is in good agreement with the earlier experimental data. The calcu-㻝㻜㻝㻌㻹㼕㼏㼔㼑㼘㻌㼑㼠㻌㼍㼘㻚㻌㻔㻯㼞㻙㻠㻤㻕㻌㼃㼑㼕㼚㼞㼑㼕㼏㼔㻌㼑㼠㻌㼍㼘㻚㻌㻔㻯㼞㻙㻠㻤㻕㻌㻴㼑㼞㼙㼍㼚㼚㼑㻌㼑㼠㻌㼍㼘㻚㻌㻔㻯㼞㻙㻠㻤㻕㻌㻼㼑㼚㼓㻌㼑㼠㻌㼍㼘㻚㻌㻔㻯㼞㻙㻠㻤㻕㻌㼀㼔㼕㼟㻌㼣㼛㼞㼗㻌㻔㻯㼞㻙㻠㻤㻕㻌㼀㼔㼕㼟㻌㼣㼛㼞㼗㻌㻔㻯㼞㻙㻠㻥㻕㻌㻌㼀㼍㼘㼥㼟㻌㻝㻚㻢㻌㻔㻯㼞㻙㻠㻤㻕㻌㼀㼍㼘㼥㼟㻌㻝㻚㻢㻌㻔㻯㼞㻙㻠㻥㻕㻜㻚㻝㻌㻜㻚㻜㻝㻝㻜㻞㻜㻟㻜㻠㻜㻡㻜㻱㼚㼑㼞㼓㼥㻌㻔㻹㼑㼂㻕

Fig. 2. Cross sections for the nat Ti(α, X)48 Cr and nat Ti(α,X)49 Cr reactions.

References
1) IAEA-Tecdoc-1211 2001 Charged particle cross section
database for medical radioisotope production: diagnostic radiosotopes and monitor reactions (IAEA, Vienna,2001).
2) J. F. Ziegler et al.: The stopping and range of ions insolids (Pergamon Press, New York, 1985).
3) R. Michel et al.: Radiochim. Acta 32,32, 173 (1983).
4) R. Weinreich et al.: Appl. Radiat. Isot. 31
31, 223 (1980).
152, 1875) A. Hermanne et al.: Nucl. Instrum. Meth. B 152,(1999).
140, 9 (1998).
6) X. Peng et al.: Nucl. Instrum. Meth. B 140,
7) A. J. Koning et al.: ”TALYS-1.0”, Proc.. Int. Conf.
Nucl. Data Sci. Technol. ND2007, Nice, France, 200704 (EDP Sciences, 2008) p.211.

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