Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 52 (2019)

Production cross sections of deuteron-induced reactions on naturalpalladium for Ag isotopes†
N. Ukon,∗1,∗2,∗3 M. Aikawa,∗3,∗4 Y. Komori,∗3 and H. Haba∗3Radioisotopes (RI) are available for medical therapy and diagnostics.1) 103 Pd with a half-life of T1/2
= 16.991 d decays (100% electron capture (EC)) into103mRh, which successively decays (100% isomeric transition) into 103 Rh with a 39.5-keV γ-ray emission. 103 Pdis a medical radioisotope and is available for brachytherapy.2) For the eﬀective production of 103 Pd, a variety ofreactions should be investigated for comparison, including reactions to produce 103 Ag (T1/2 = 65.7 min), which
is a parent of 103 Pd. One of the processes used for producing 103 Ag is deuteron-induced reactions on naturalpalladium, which has only been studied up to 20.3 MeV
in previous studies.3–5)
In addition to 103 Pd, the radionuclide 104g Ag which
has a short β + decay half-life (T1/2 = 69.2 min) can beused for diagnostic imaging in positron emission tomography (PET). 111 Ag has signiﬁcant potential as a therapeutic β − radionuclide decaying (92% β − , Eβ max ) =1037 keV) directly to the ground state of 111 Cd. The
PET using 104 Ag has the possible combination of diagnostic studies to investigate the uptake of 111 Ag labelled compounds of the therapeutic radionuclide before
treatment.6) Ag, 104m, g Ag, and 111 Ag can be obtained bycharged particle reactions on nat Pd. Therefore, we investigated the activation cross sections of deuteron-induced
reactions on metallic foils of natural palladium (102 Pd1.02%; 104 Pd 11.14%; 105 Pd 22.33%; 106 Pd 27.33%;
108
Pd 26.46%; 110 Pd 11.72%) in connection with theproduction of medically relevant radioisotopes.
The excitation functions of the nat Pd(d, x) reactions
were measured by the stacked-foil method, activation
method and high-resolution γ-ray spectroscopy. nat Pdfoils (purity: 99.95%, Nilaco Corp., Japan) were stacked
with nat Ti (purity: 99.6%, Nilaco Corp., Japan) andnatZn foils (purity: 99.95%, Nilaco Corp., Japan) for
monitoring the beam parameters and degrading thebeam energy. The thicknesses of the Pd, Ti, andZn foils were 8.15, 4.93, and 25.14 mg/cm2 , respectively.The irradiation was performed at the RIKEN AVF
cyclotron. A 24-MeV deuteron beam with an average intensity of about 174 nA was irradiated on the target for
20 min. The incident beam energy was measured by
the time-of-ﬂight method using plastic scintillator monitors. The beam energy degraded in the stacked target
was calculated using the polynomial approximation ofstopping-power data.7) The γ-ray spectra of the acti†∗1∗2∗3∗4Condensed from the article in Nucl. Instrum. Methods Phys.
Res. B 426, 13 (2018)
Nuclear Reaction Data Center (JCPRG), Hokkaido University
Advanced Clinical Research Center, Fukushima Medical University
RIKEN Nishina Center
Faculty of Science, Hokkaido University

Fig. 1. Excitation function of the nat Pd(d, x)103 Ag reaction.
The result is compared with a previous study4) andTENDL-2017.9)

vated foils were measured using HPGe detectors. The
nuclear decay data were taken from the online NuDat
2.6 database.8)
We found that our result is in good agreement withthe previous data obtained by Hermanne et al.4) up
to 20.3 MeV. On the other hand, the theoretical calculation reproduces well the experimental cross sections up to 15 MeV; however at higher energies, thecalculation overestimates the experimental cross sections. We performed an experiment of the deuteroninduced reactions on natural palladium to produce Ag
isotopes by using the stacked foil activation technique.
The excitation functions of the nat Pd(d, x)103 Ag reaction from 20.3 MeV to 24 MeV, nat Pd(d, x)104g Ag, andnatPd(d, x)104m Ag were measured for the ﬁrst time. Theproduction cross sections of 105 Ag, 106m Ag, 110m Ag, and111
Ag are in good agreement with the previous experimental data. Above 20.3 MeV, all excitation functionsin this work continued smoothly to the data in the previous study.
References
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8) National Nuclear Data Center: the NuDat 2 database,
http://www.nndc.bnl.gov/nudat2/.
9) A. J. Koning et al., TENDL-2017: TALYS-based evaluated nuclear data library.

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