Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 49 (2016)

Excitation function of α-induced reaction on nat Pd for 103 Agproduction
M. Aikawa,∗1,∗2 M. Saito,∗3,∗2 H. Haba,∗2 Y. Komori,∗2 S. Takács,∗4 F. Ditrói,∗4 and Z. Szücs∗4

∗1
∗2
∗3
∗4

Faculty of Science, Hokkaido University
RIKEN Nishina Center
Graduate School of Science, Hokkaido University
MTA ATOMKI, Hungarian Academy of Sciences- 247 -

Result (Preliminary)
Hermanne et al. (2005)
TENDL-2014

1210σ (mb)Radioactive isotopes (RIs) are available in many application ﬁelds, such as engineering and medicine. Production of such RIs is possible through various reactions involving combinations of projectiles and targets.
The best process to obtain RIs can be discussed basedon the information of all the reactions. The production
cross sections induced by neutrons and light chargedparticles thus constitute fundamental information forthe applications.
One such RI for medical applications is 103 Pd(T1/2 = 16.991 d) for brachytherapy1,2) and targetedradionuclide therapy as part of the 103 Pd/103m Rh invivo generator3) . In addition to direct 103 Pd production, the production of its generator, 103 Ag, is worthlyof investigation. 103 Ag has the isomeric state 103m Ag
at 134.4 keV (T1/2 = 5.7 s, IT: 100%), which cumulatively contributes to 103g Ag (T1/2 = 65.7 min, � + β + :100%) production through IT decay. In the case of
α-induced reactions on nat Pd, only experimental data
are available only below 37 MeV4) . Therefore, we performed an experiment to obtain the excitation function of nat Pd(α,x)103 Ag up to about 50 MeV. This experiment is promising as it would provide fundamental information for establishing the best process for103
Ag/103 Pd production.
The experiment was performed at the RIKEN AVF
cyclotron by using the stacked foil technique and theactivation method. nat Pd foils (purity: 99.95%, Nilaco, Japan) were used with nat Ti monitor foils (purity: 99.9%, Goodfellow, UK). The thicknesses of thePd and Ti foils were 9.80 mg/cm2 and 4.95 mg/cm2 ,respectively. The stacked target consisted of 12 sets ofthe Pd-Pd-Ti-Ti foils to reduce the possible recoil effect in every second foil. The target was irradiated for2 h by the 51.2 MeV α beam with the average intensityof 55.7 pnA. This beam energy was measured by thetime-of-ﬂight method using a plastic scintillator monitor5) . γ rays from the irradiated foils were measuredby HPGe detectors.
According to the NuDat 2.6 database6) , there aremany speciﬁc γ lines from 103g Ag decays. We adopted
the intense γ line at 118.74 keV (31.2%) to derive theproduction cross sections of 103g Ag since the γ line
at 148.20 keV (28.3%) overlaps with that of 111m Cd(T1/2 = 48.54 min, IT: 29.1%) at 150.824 keV. Our
preliminary result is shown in Fig. 1 with the previous experimental data4) and theoretical calculation of864
20303540E (MeV)

4550Fig. 1. Excitation function of the nat Pd(α,x)103g+m Ag reaction. Our preliminary result (solid circles) with statistical errors is compared with the previous experimental data (open triangles)4) and the theoretical calculation7) of 102 Pd(α,x)103 Ag with normalization of the102
Pd abundance.

102Pd(α,x)103 Ag in TENDL-20147) with normalizationof the 102 Pd abundance (1.02%). Our result showsslightly larger values than the previous data4) below
37 MeV. The peak could be found at around 42 MeV
in our result but at around 45 MeV in TENDL-20147) .
Further analysis will be performed on the data and theTi monitor reaction to ﬁnalize the result.
In summary, we performed an experiment onnatPd(α,x)103g+m Ag by using the stacked foil technique and the activation method. The preliminary result of the excitation function of the reaction showsslightly diﬀerent values from the previous experimentand theoretical calculation. The ﬁnal result based on
further analysis will be reported in a separate paper.
We will also analyze the spectral data to derive production cross sections of other RIs.
This work is supported by the Japan - Hungary Research Cooperative Program, JSPS and HAS.
References
1) S. Nag et al., Int. J. Radiat. Oncol. Biol. Phys. 44, 789(1999).
2) A. Hermanne et al., Radiochim. Acta 92, 215 (2004).
3) Z. Szücs et al., Appl. Rad. Isot. 67, 1401 (2009).
4) A. Hermanne et al., Nucl. Instr. Meth. B 229, 321(2005).
5) T. Watanabe et al.: Proc. 5th Int. Part. Accel. Conf.
(IPAC2014) (2014), p.3566.
6) National Nuclear Data Center: the NuDat 2 database,
http://www.nndc.bnl.gov/nudat2/.
7) A.J. Koning et al.: TENDL-2014: TALYS-based evaluated nuclear data library.