•The excitation functions of alpha-particle-induced reactions on natLa up to 50 MeV were measured.•The production cross sections of 139,138m,142Pr, and 141,139Ce were determined.•The results were ...compared with the previous experimental data and the TENDL data.•The physical yield of the medical radionuclide 142Pr was derived from the measured cross sections.
We performed experiments to measure the activation cross sections of α-particle-induced reactions on natLa up to 50 MeV. The production cross sections of the medical radionuclide 142gPr and simultaneously formed 139,138mPr, and 141,139gCe were obtained. The stacked-foil activation method and the high-resolution γ-ray spectrometry were employed for the measurements. The results were compared with previous experimental data and theoretical values deduced by TALYS (TENDL library). The production cross section data for 139gCe and 138mPr were determined for the first time.
•Activation cross sections of deuteron-induced reactions on natural chromium were measured up to 24 MeV.•The stacked-foil activation method and high-resolution gamma-ray spectrometry were used for ...the measurement.•Production cross sections of 48V, 51Cr, 52g,52m,54Mn were determined in this experiment.•The results were compared with the previous experimental data and the TENDL-2019 values.
Radioisotopes in the transition elements such as 51Cr and 52gMn can be used for medical applications. Investigation on the production reactions of such radioisotopes is valuable. Therefore, excitation functions of the natCr(d,x)48V, 51Cr, 52g,52m,54Mn reactions were measured up to 24-MeV deuteron energy. The experiment was performed at the RIKEN AVF cyclotron. Stacked-foil activation method and gamma-ray spectrometry were used for the measurement. The results were compared with previous experimental data and the prediction values of TENDL-2019. Physical thick target yields of 51Cr and 52gMn were derived from the measured cross sections.
Activation cross sections of alpha-particle-induced reactions on natural vanadium were measured. The production cross sections of 54, 52gMn, 51Cr, 48V, and 47, 46gSc were determined up to 50 MeV. The ...stacked-foil activation technique and high-resolution gamma-ray spectrometry were used. The experimental results were compared with previous experimental data and theoretical calculations in the TENDL-2019 library. The physical yield of the medical radionuclide 52gMn was derived from the measured cross sections.
•The excitation functions of alpha-particle-induced reactions on natV up to 50 MeV were measured.•The production cross sections of 54,52gMn, 51Cr, 48V, and 47,46gSc were determined.•The results were compared with the previous experimental data and the TENDL data.•The physical yield of the medical radionuclide 52gMn was derived from the measured cross sections.
Activation cross sections of deuteron-induced reactions on natural gadolinium were measured up to 24 MeV. The stacked-foil activation technique and γ-ray spectrometry were used for the measurement. ...The production cross sections of 153,154m1,154m2,155,156,160,161Tb and 153,159Gd were determined. The cross sections were compared with previous experimental data and TENDL values.
To investigate sulfate complex formation of Rf, we performed batch-wise ion-exchange experiments of its homologues Zr and Hf and its pseudo homologue Th in H
2
SO
4
using anion- and cation-exchange ...resins and fibers. From the time dependence of the distribution ratios, it was found that the anion-exchange resin is applicable for the experiments with the
261
Rf
a
. To obtain the comparison data for Rf, we investigated the distribution coefficients of Zr, Hf, and Th in 0.06–1 M H
2
SO
4
. From these results, we propose the anion-exchange experiments of Rf with the resin in 0.1–0.7 M H
2
SO
4
using the extraction apparatus (AMBER).
To observe the γ rays emitted from the low-lying isomeric state of
229
Th (
229m
Th), we aim to dope fluoride crystals with its precursor
229
Pa. In this study, we produced
229
Pa by a 30 MeV proton ...bombardment on
232
Th and developed a chemical separation method. The chemical yield of Pa was 93(4)%, and the physical production yield of
229
Pa for the proton energy range of 29.0–30.1 MeV was measured to be 9.4(8) MBq/µAh, which was more than 10 times higher than those of
232,230,228,233
Pa. These high chemical and production yields will allow us to prepare fluoride crystals having a sufficient amount of
229
Pa for the observation of the γ rays of
229m
Th.
The periodic table as we know it now seems complete, its current 118 elements nicely fitting in the seven familiar rows. How many more can be synthesized — and how will the table expand to ...accommodate them? The search for ever-heavier elements is pointing towards new periods, though perhaps not as neatly ordered as the first seven.
A gas-jet transport system has been installed to the RIKEN GAs-filled Recoil Ion Separator, GARIS to start up SuperHeavy Element (SHE) chemistry. This system is a promising approach for exploring new ...frontiers in SHE chemistry: background radioactivities from unwanted by-products are suppressed, a high gas-jet transport yield is achieved, and new chemical reactions can be investigated. Useful radioisotopes of 261Rfa,b, 262Db, and 265Sga,b for chemical studies were produced in the reactions of 248Cm(18O,5n)261Rfa,b, 248Cm(19F,5n)262Db, and 248Cm(22Ne,5n)265Sga,b, respectively. They were successfully extracted to a chemistry laboratory by the gas-jet method. Production and decay properties of 261Rfa,b, 262Db, and 265Sga,b were investigated in detail with the rotating wheel apparatus for α- and spontaneous fission spectrometry. Present status and perspectives of the SHE chemistry at GARIS are also briefly presented.
Activation cross sections of proton-induced reactions on natural platinum were measured. The stacked-foil activation technique and high-resolution gamma-ray spectrometry were used. The production ...cross sections of 198, 196, 196m2, 195, 194, 193, 192, 191Au, 191Pt, and 192, 190Ir were determined up to 30 MeV. The experimental results were compared with previous experimental data and theoretical calculations in the TENDL-2019 library.
•The excitation functions of proton-induced reactions on natPt up to 30 MeV were measured.•The stacked-foil activation technique and gamma-ray spectrometry were used.•The production cross sections of 198, 196, 196m2, 195, 194, 193, 192, 191Au, 191Pt, and 192, 190Ir were determined.•The results were compared with the previous experimental data and the TENDL data.
PDF