RIKEN Accel. Prog. Rep. 50 (2017)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

Excitation functions of natCu(ǂ, x)57,58g+mCo nuclear reactions†
A. R. Usman,䠆1,䠆2 M. U. Khandaker,䠆1,䠆2 H. Haba,䠆1 N. Otuka,䠆1,䠆3 M. Murakami,䠆1 and Y. Komori䠆1
Studies on radionuclides production cross-sections
through the (p,x) route is relatively more active compared tothe other light-charged particles production-routes, thoughsometimes, the production of the same radionuclides are
more effective via the (d,x) or (Į,x) reaction process. Usingcopper (Cu) as a target material, several importantradionuclides can be produced. Some of such radionuclides
are gallium (Ga) and cobalt (Co) radionuclides. In particular,
66
Ga was recently tested in in vivo studies as 66Ga-labelednano-graphene and reported to be a good candidate for
imaging (PET) of vascular system1). The radionuclide 67Ga
(T1/2 = 3.2617 d) is useful due to its short half-life and theAuger and Coster-Kronig electron emissions, making
67
Ga-labeled radiopharmaceuticals more appropriate topatients (in clinical terms) compared to its prototype 125I
(T1/2 = 59.4 d) equivalent 2). Additionally, 57Co is a popular
candidate in Mössbauer spectroscopy and also as acalibration standard in Ȗ-ray spectrometry as well as insingle photon emission computed tomography (SPECT) 3).
Our extensive literature survey of previous experimental
data shows that Cu have been used as target inradionuclides production. However, these studies reported
mainly the production of Ga and Zn radionuclides for Į
beam monitoring purposes. In addition, there are also
obvious discrepancies among the studies in the reported
data. More so, the reported studies on cobalt (Co)radionuclides through this route is relatively less. Present
work therefore reports new Į-particle-induced reaction
cross-sections on natCu to reduce the observed discrepancies
and also to enrich Co production cross-sections database.
The stacked-foil activation method and Ȗ-ray
spectrometry were used for the excitation functions
measurements. The stack was irradiated for 2.0 hours by a50.4 MeV Į beam in a Faraday cup-like water-cooled target
holder using AVF cyclotron of the RIKEN RI Beam Factory,
Japan. The intensity of the beam was determined from themeasured activities of the front Ti of the stack, the foil
directly facing the incident beam. The natTi(Į,x)51Cr IAEA 4)
recommended monitor reaction (ı = 26.4 mb at Ed = 50.0
MeV) was used for the evaluation of the beam intensity.
The intensity was considered as a constant in the stack andwas used to deduce cross-sections of the 51Cr from each Ti
foil of the stack.
The production cross-sections of 66,67Ga, 65Zn, and57,58g+m,60
Co have been assessed and presented with theirrelevant total uncertainties in Tables of Ref.4) while thecorresponding excitation factions of these radionuclides†

have been presented in the Figures of Ref.4).
The present results were compared with the previous
experimental data as well as the extracted theoretical
TENDL-2014 data. Due to space constrain, only excitation
functions of 57Co and 58g+mCo are presented in this report.
The cross-sections of 57Co (T1/2 = 271.74 d) were assessedusing its interference-free Ȗ line (EȖ = 122.0607 keV; IȖ =85.60%). The evaluated TENDL-2014 library data indicatethat the 57Co production is due to the 63Cu(Į,2n2Į)57Co
process below 50 MeV. Two earlier studies5,6) have beenreported for the production of 57Co. The TENDL-2014
library reproduced the excitation function of 58g+mCo moreclosely as compared to 57Co.

Fig. 1. Excitation function of the natCu(Į,x)57Co reaction.

Fig. 2. Excitation function of the natCu(Į,x)58g+mCo reaction.
References
1) H. Hong et al.: Biomaterials 33, 4147 (2012).
2) E. Koumarianou et al.: Nucl. Med. Bio. 41, 441 (2014).
3) A. R. Usman et al.: Nucl. Instr. Meths Phys. B 368, 112 (2016).
4) A. R. Usman, et al.: Appl. Radiat. Isot. 114, 104 (2016).
5) S. S. Rattan etal.: Radiochimica Acta 39, 61 (1986).
6) M. J. Ozafrán et al.: J. Radioanal. Nucl. Chem. 131, 467 (1989).

Condensed from the article in Appl. Radiat. Isot. 114, 104 (2016)
1
RIKEN Nishina Center2
Department of Physics, University of Malaya
3
Nuclear Data Section, International Atomic Energy Agency- 256 -