RIKEN Accel. Prog. Rep. 50 (2017)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

Activation cross sections of deuteron-induced reactions on natural palladium
for 103Ag production
N. Ukon,*1,*2 M. Aikawa,*2,*3 Y. Komori,*2 and H. Haba*2103

Pd with a half life of 16.991 days decays (100% electron
capture (EC)) to 103mRh (100% isomeric transition to 103Rh
with 39.5-keV J-ray emission) is a medical radioisotope (RI)
for brachytherapy. For the effective production of 103Pd, avariety of reactions should be investigated. They also include
reactions to produce 103Ag (T1/2 = 65.7 min), a parent of 103Pd.
A process to produce 103Ag is a deuteron-induced reaction on
natural palladium, which has only been studied up to 20.3MeV.1) Therefore, we measured the activation cross sectionsof the natPd(d,x)103Ag reaction using a 24-MeV deuteronbeam.
The excitation function of the natPd(d,x)103Ag reaction wasmeasured by the stacked-foil method, activation method andhigh-resolution J-ray spectroscopy. natPd foils (purity:99.95%, Nilaco Corp., Japan) were stacked with natTi (purity:99.6%, Nilaco Corp., Japan) and natZn foils (purity: 99.95%,Nilaco Corp., Japan) for monitoring the beam parameters anddegrading the beam energy. The thicknesses of Pd, Ti and Zn
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 averageintensity of 174.74 nA was irradiated on the target for 20 min.
The incident beam energy was measured by the time-offlight method using plastic scintillator monitors. The beamenergy degraded in the stacked target was calculated using
the polynomial approximation of stopping-power data.2) The
J-ray spectra of the activated foils were measured by HPGedetectors. Nuclear decay data are summarized in Table 1 andare taken from the online NuDat 2.6 database.3)
From the net peak area of the 118.75-keV J-ray, theactivation cross sections for the natPd(d,x)103Ag reaction werededuced using the standard activation formulaߪൌ

Table 1. Decay data of 103Ag.
Nuclide103

AgT1/2

EJ (keV)

IJ (%)

65.7 min118.74

31.2

148.2

28.3

266.8613.3

531.928.8

1273.83

9.4

Fig.1. Excitation function of the natPd(d,x)103Ag reactions.
The result is compared with a previous study1) andTENDL-2015. 4)
We found that our result is in good agreement withprevious data obtained by Hermanne et al.1) up to 20.3 MeV.
On the other hand, the theoretical calculation reproduces
well the experimental cross sections up to 15 MeV, while athigher energies, the calculation overestimates the crosssection. This is probably because the theoretical calculation
overestimates cross section of the 104Pd (d,3n)103Ag reaction.
In conclusion, we performed an experiment of deuteroninduced reactions on natural palladium to produce 103Ag. The
excitation function of the natPd(d,x)103Ag reaction wasmeasured for the first time from 22 MeV to 24 MeV.

ܶఊ ߣିఒ௧ߝௗ ߝఊ ߝ௧ ܰ௧ ܰ௕ ሺͳ െ ݁ ್ ሻ݁ ିఒ௧೎ ሺͳ െ ݁ ିఒ௧೘ ሻ

where Nt denotes the surface density of target atoms: Nb thenumber of bombarding particles per unit time: TȖ the numberof counts in photo-peak: İd the detector efficiency: İȖ thegamma ray abundances: İt the measurement dead time, whichis the ratio of live time to real time: Ȝ the decay constant: tb
the bombarding time: tc the cooling time: and tm acquisition
time.

References1)2)

䠆1

Nuclear Reaction Data Center (JCPRG), Hokkaido University
RIKEN Nishina Center
䠆3
Faculty of Science, Hokkaido University

3)

䠆24)

- 258 -A. Hermanne et al., Radiochim. Acta 92, 215 (2004).
H. H. Andersen, J. F. Ziegler: Hydrogen Stopping Powers andRanges in All Elements, Vol. 3 (Pergamon, Oxford, 1997).
National Nuclear Data Center: the NuDat 2 database,
http://www.nndc.bnl.gov/nudat2/.
A. J. Koning et al.: TENDL-2015: TALYS-based evaluatednuclear data library.