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Cross sections of alpha-particle induced reactions were determined on antimony targets using alpha-particle irradiation with a primary energy of 50 MeV. The standard stacked target technique, activation method and offline gamma-ray spectrometry were applied for determination of the reaction cross sections. Thin Sb targets prepared by vacuum evaporation onto Kapton backings were activated. Ti foils were inserted into the stack for monitoring the alpha-particle beam parameters and energy loss of the particles in the target by using the natTi(α,x)51Cr monitor reaction. Reaction cross sections for formation of 121,123,124,125,126I, 121m,g,123m,125mTe and 118m,120m,122gSb were determined and compared to the available literature data and theoretical estimation of the cross sections from the TENDL-2019 data library.

Clinical studies intended for regulatory approval must demonstrate the clinical benefits of the drug in a target population. Clinical development of a drug proceeds by stepwise clinical studies; after safety and pharmacokinetics are evaluated and the recommended dosage and administration are determined, efficacy and safety are evaluated in an exploratory manner, and finally clinical benefits are compared with conventional standard therapies. Guidelines for the clinical evaluation of anti‐cancer drugs in Japan were established in 1991 and amended in 2006 after molecular‐targeted drugs were introduced. Recent progress in the development of drugs acting on the immune system and cancer genomic medicine targeting rare but important molecular subtypes have altered the strategy for development of anti‐cancer drugs. It is often difficult to conduct a confirmatory randomized controlled study using overall survival as the primary endpoint in rare molecular subtypes, and the primary evaluation of the efficacy of some drugs and subsequent approval is based on the tumor response. As conducting clinical studies for rare subtypes solely within Japan is difficult, drug development needs to be conducted within a global study. However, this requires robust monitoring to detect possible ethnic differences in pharmacokinetics and drug efficacy. Development using the conditional approval system for drugs enforced in 2020 may be considered, when clinical utility is evaluated based on surrogate endpoints. Because of these changes, we have revised the guidelines for the clinical evaluation of anti‐cancer drugs in Japan. To promote global development of anti‐cancer drugs involving Japan, the guidelines have been translated into English., Recent progress in development of drugs acting on the immune system and cancer genomic medicine targeting rare but important molecular subtypes have altered the strategy for development of anti‐cancer drugs. As conducting clinical studies for rare subtypes solely within Japan is difficult, drug development needs to be conducted within a global study with monitoring possible ethnic differences. Because of these changes, we have revised the guidelines for the clinical evaluation of anti‐cancer drugs in Japan.

The activation cross sections of the alpha-particle-induced reactions on natural gadolinium up to 50 MeV were measured. The stacked foil technique, the activation method and the γ-ray spectrometry were used for the measurement. We determined the experimental production cross sections of 155,157,159Dy, 153,155,156g,160,161Tb and 153Gd. No previous experimental data of 155,159Dy, and 153Gd were found in the literature. The measured values were compared with the previous experimental data and the TENDL-2019 data.

Activation cross sections of proton-induced reactions on 141Pr were measured. Stacked foil activation technique and γ-ray spectrometry were adopted to derive the cross sections. The production cross sections of 141,140,139mNd, and 139Ce were determined up to 30 MeV. The physical yield of 140Nd was deduced using the measured cross sections of the 141Pr(p,2n)140Nd reaction. The physical yields of the proton- and deuteron-induced reactions on 141Pr and 3He-induced reaction on natCe for 140Nd production were compared.

211At, an α-particle emitter, has recently attracted attention for radioimmunotherapy of intractable cancers. However, our sodium dodecyl sulfate polyacrylamide gel electrophoresis and flow cytometry analyses revealed that 211At-labeled immunoconjugates are easily disrupted. Luminol assay revealed that reactive oxygen species generated from radiolysis of water caused the disruption of 211At-labeled immunoconjugates. To retain their functions, we explored methods to protect 211At-immunoconjugates from oxidation and enhance their stability. Among several other reducing agents, sodium ascorbate most safely and successfully protected 211At-labeled trastuzumab from oxidative stress and retained the stability of the 211At-labeled antibody and its cytotoxicity against antigen-expressing cells for several days.

Tissue factor (TF), the trigger protein of the extrinsic blood coagulation cascade, is abundantly expressed in various cancers including gastric cancer. Anti‐TF monoclonal antibodies (mAbs) capable of targeting cancers have been successfully applied to armed antibodies such as antibody‐drug conjugates (ADCs) and molecular imaging probes. We prepared an anti‐TF mAb, clone 1084, labeled with astatine‐211 (211At), as a promising alpha emitter for cancer treatment. Alpha particles are characterized by high linear energy transfer and a range of 50‐100 µm in tissue. Therefore, selective and efficient tumor accumulation of alpha emitters results in potent antitumor activities against cancer cells with minor effects on normal cells adjacent to the tumor. Although the 211At‐conjugated clone 1084 (211At‐anti‐TF mAb) was disrupted by an 211At‐induced radiochemical reaction, we demonstrated that astatinated anti‐TF mAbs eluted in 0.6% or 1.2% sodium ascorbate (SA) solution were protected from antibody denaturation, which contributed to the maintenance of cellular binding activities and cytocidal effects of this immunoconjugate. Although body weight loss was observed in mice administered a 1.2% SA solution, the loss was transient and the radioprotectant seemed to be tolerable in vivo. In a high TF–expressing gastric cancer xenograft model, 211At‐anti‐TF mAb in 1.2% SA exerted a significantly greater antitumor effect than nonprotected 211At‐anti‐TF mAb. Moreover, the antitumor activities of the protected immunoconjugate in gastric cancer xenograft models were dependent on the level of TF in cancer cells. These findings suggest the clinical availability of the radioprotectant and applicability of clone 1084 to 211At‐radioimmunotherapy., Although the astatinated anti–tissue factor (TF) monoclonal antibody (mAb) was disrupted by an astatine‐211–induced radiochemical reaction, we demonstrated that the immunoconjugates eluted in 0.6 or 1.2% sodium ascorbate (SA) solution were protected from antibody denaturation, which contributed to maintaining their cellular binding and antitumor activities. In gastric cancer xenograft models, astatine‐211–conjugated anti‐TF mAb protected by 1.2% SA exerted a potent antitumor effect dependent on TF expression on the cell membrane.

All superheavy elements (SHEs), with atomic numbers (Z) ≥104, have been artificially synthesized one atom at a time and their chemical properties are largely unknown. Because these heavy nuclei have short lifetimes as well as extremely low production rates, chemical experiments need to be carried out on single atoms and have mostly been limited to adsorption and extraction. We have now investigated the precipitation properties of the SHE Rf (Z = 104). A co-precipitation method with samarium hydroxide had previously established that the co-precipitation behaviour of a range of elements reflected these elements’ tendency to form hydroxide precipitates and/or ammine complex ions. Here we investigated co-precipitation of Rf in basic solutions containing NH3 or NaOH. Comparisons between the behaviour of Rf with that of Zr and Hf (lighter homologues of Rf) and actinide Th (a pseudo-homologue of Rf) showed that Rf does not coordinate strongly with NH3, but forms a hydroxide (co)precipitate that is expected to be Rf(OH)4. It is difficult to investigate the chemical properties of superheavy elements, which are only available an atom at a time and rapidly decay. A co-precipitation method with samarium has now been developed that suggests rutherfordium would form hydroxide precipitates—but not ammine ones—if it were possible to perform these experiments on macroscopic quantities.

The 67Cu is considered as one of the most perspective radio isotopes in targeted radio-immunotherapy medical applications. 67Cu is a β–-emitter with a mean β– energy, which allows treating tumors in size up to about 4 mm. Its decay is followed by emission of low energy gamma-rays suitable for gamma-camera imaging. The about three days half-life (T1/2 = 61.83 h) is optimal for human applications. However, one of the main drawback factors for its application is still the limited supply of 67Cu. There are several possibilities to produce 67Cu. High flux reactors, charged particle accelerators and high-energy bremsstrahlung radiations can be used to produce 67Cu. In this work we have studied one of the promising charged particle production routes based on the 64Ni(α,p)67Cu nuclear reaction. Cross sections for formation of 67,64,61,60Cu, 62,63Zn and 56,57Ni were studied up to 50 MeV alpha-particle energy on nickel targets with natural isotopic composition.

Activation cross sections of the deuteron-induced reactions on 89Y were measured up to 24 MeV deuteron energy. The experiment was performed at the RIKEN AVF cyclotron. Excitation functions of the reactions 89Y(d,x)88,89Zr, 88,90mY, 87mSr were obtained by using the stacked-foil activation method and gamma-ray spectrometry. The results were compared with previous experimental data and the prediction of the TALYS nuclear reaction model code adopted from TENDL-2017 library. Physical thick target yield of 89Zr was derived from the measured cross sections.

Activation cross sections of the 169Tm(p,n)169Yb reaction were measured up to 18 MeV. The stacked-foil activation technique and the high-resolution gamma-ray spectrometry were adopted to derive the cross sections. The result is compared with previous experimental data and theoretical model calculation. Physical yield of 169Yb is derived from the measured cross sections and compared with those from other production routes.

Excitation functions for the natEr(d,x)163,165,166,167,168,170Tm and natEr(d,x)171Er nuclear reactions were measured from the respective thresholds up to 24 MeV by using a stacked-foil activation technique combined with HPGe γ-ray spectrometry. Measured data show a partial agreement when compared with the available literature data, theoretical data extracted from the TENDL-2019 library, and predicted data by the model code EMPIRE-3.2.2. Estimated physical thick target yields of the reaction products show close values to the directly measured ones available in the literature. The deduced yield curves indicate that a typical irradiation (Ed = 15 MeV, Id = 100 µA, tirr = 72 h) of enriched 167Er target by a low energy deuteron cyclotron is suitable to obtain more than a hundred GBq activity of 167Tm with negligible impurity from 168Tm. Measured data of 170Er(d,p)171Er reaction have great significance to improve the predicting capability of the model code.

Chemical studies of transactinide elements (atomic number Z ≥ 104) are of great importance to understand the relativistic effects; however, the experimental methodology is limited owing to the sing...

Production cross sections of

Experimental production cross sections of the deuteron-induced reactions on terbium-159 up to 24 MeV were measured. The stacked foil technique, the activation method and the γ-ray spectrometry were used for the measurement. The production cross sections of 157,159Dy and 160Tb were determined and compared with the experimental data studied earlier and the theoretical calculation.

An experiment of α -induced reactions on yttrium-89 was performed to investigate the excitation functions of 89 Zr and 90 Nb , which are suitable for immuno-PET studies. The stacked-foil method, activation technique, and off-line γ -ray spectrometry were used for this investigation. The excitation functions of 92 m , 91 m , 89 m , 89 g Nb , 88 Zr , and 90 m , 88 g , 87 m , 87 g Y were also derived and compared with earlier experimental and the TENDL-2017 data. Good agreements with part of the previous studies were found.

As an alternative production route for the medically interesting 178mTa isotope production cross sections of alpha particle induced nuclear reaction of the natHf(α,x)178W–178mTa process was investigated. Activation method, stacked target technique, and high resolution off-line γ-ray spectrometry were applied. Excitation functions of the natHf(α,x)178W reaction and of several other side reactions were determined up to 51 MeV. Activation cross section data were determined for the following reactions: natHf(α,x)176,177,178W, natHf(α,x)175,176,177,178g,180g,182g,183Ta, and natHf(α,x)173,175,179m2,180m,181Hf. The measured experimental data were compared with the results of earlier experimental data and the results of TALYS nuclear reaction model code calculation tabulated in the TENDL-2017 data library. Experimental data are presented for the first time in the 40–50 MeV energy region. Thick target yields were calculated for elemental hafnium target using the fitted experimental cross section data.

Activation cross sections of α-particle induced reactions on natYb were measured. The stacked foil technique, the activation method and the γ-ray spectrometry were used. The stacked target consisted of natYb and natTi foils was irradiated with a 51.0-MeV α beam at the RIKEN AVF cyclotron. The γ rays emitted from the irradiated foils were measured using a high-resolution HPGe detector. Production cross sections of 170,171,172,173,175Hf, 171,172,173,177gLu and 169Yb were determined. The results were compared with previous experimental studies and theoretical calculations. For most of the reactions a consistent agreement was found.

The activation cross sections of the alpha-particle induced reactions on natural palladium were determined up to 50 MeV using the stacked-foil technique and high-resolution gamma-ray spectrometry. Production cross sections of 111m,109,107,105,104Cd and 111g,110m,106m,105g,103gAg were obtained. The results were compared with the data of previous experiments and results of theoretical model calculations.

This work presents the recoil and secondary implantation of radioisotopes at different bombarding energies in the range of ~ 13 to ~ 40 MeV by using an α-particle beam of 50 MeV irradiating a stack of Ag, Ni and Ti metal foils. Activation cross-sections for the produce radioisotopes were calculated and confronted with literature data. The implanted activity is presented as a function of the primary beam energy for six produced radioisotopes 57Ni, 57Co, 65Zn, 51Cr, 48V and 46Sc. The use of each of these radioisotopes in engineering experiments based on the nano-thin layer activation is discussed.

Cross sections of α-induced reactions on natural zirconium were measured up to 50 MeV using the stacked-foil technique, activation method and high resolution γ-ray spectrometry. The production cross sections of 93m,99Mo, 90g,92m,95g,95m,96Nb and 88,89g,95Zr were determined and compared with other experimental data measured earlier and result of theoretical calculations. The integral thick target yield of 99Mo was deduced from the measured cross section data.

Natural silver targets have been irradiated by using a 50 MeV alpha-particle beam in order to measure the activation cross sections of radioisotopes in the 40–50 MeV energy range. Among the radio-products there are medically important isotopes such as 110mIn and 111In. For optimizing the production of these radioisotopes and regarding their purity and specific activity the cross section data for every produced radioisotope are important. New data are measured in this energy range and the results of some previous measurements have been confirmed. Physical yield curves have been calculated by using the new cross section data completed with the results from the literature.

Online gas-solid adsorption studies with single atom quantities of Hg, Tl, and Pb on SiO$_{2}$ and Au surfaces were carried out using short-lived radioisotopes with half-lives in the range of 4-49 s. This is a model study to measure adsorption enthalpies of superheavy elements Cn, Nh, and Fl. The short-lived isotopes were produced and separated by the gas-filled recoil separator TASCA at GSI. The products were stopped in He gas, and flushed into gas chromatography columns made of Si detectors whose surfaces were covered by SiO$_{2}$ or Au. The short-lived Tl and Pb were successfully measured by the Si detectors with the SiO$_{2}$ surface at room temperature. On the other hand, the Hg did not adsorb on the SiO$_{2}$ surface, but adsorbed on the Au surface. The results demonstrated that the adsorption properties of short-lived Hg, Tl, and Pb could be studied with this setup, and that this method is applicable to the experiment for Cn, Nh, and Fl., 半減期4$\sim$49秒の短寿命同位体を用いて、水銀(Hg), タリウム(Tl), 鉛(Pb)の単一原子レベルでのSiO$_{2}$及びAu表面への固体吸着挙動をオンライン気相実験により調べた。超重元素Cn, Nh, Flの吸着エンタルピー測定のためのモデル実験として実施した。短寿命同位体はドイツ重イオン研究所の反跳核分離装置TASCAを用いて生成・分離した。生成核はヘリウムガス中に捕集された後、SiO$_{2}$あるいはAuで表面を覆われたSi検出器で作製されたガスクロマトグラフィーカラムへと導入した。短寿命Tl及びPb同位体は室温においてSiO$_{2}$表面に吸着し、Si検出器で測定することに成功した。一方、HgはSiO$_{2}$表面には吸着せず、Au表面に吸着した。この結果より、本実験のセットアップを用いることで短寿命Hg, Tl, Pb同位体の吸着特性を調べることができると証明され、この手法がCn, Nh, Flの実験にも適用できることが確認された。

We measured cross sections of deuteron-induced reactions on a niobium target up to 24 MeV using the stacked-foil activation technique and off-line γ-ray spectrometry. The production cross sections of 93mMo, 92mNb and 89Zr were determined. The results were compared with the experimental data studied earlier and the predictions of theoretical calculations.

Excitation functions of alpha-particle induced reactions on natNd up to 50 MeV were measured at the RIKEN AVF cyclotron. To derive cross sections activation method, stacked target technique and gamma-ray spectrometry were adopted. Formations of 153,145Sm, 151,150,149,148m,148g,144,143Pm, and 149,147Nd were investigated. The results were compared with the previous experimental data and the TENDL-2019 data. Discrepancies among most of them were found.

211At, an α-particle emitter, has recently attracted attention for radioimmunotherapy of intractable cancers. However, our sodium dodecyl sulfate polyacrylamide gel electrophoresis and flow cytometry analyses revealed that 211At-labeled immunoconjugates are easily disrupted. Luminol assay revealed that reactive oxygen species generated from radiolysis of water caused the disruption of 211At-labeled immunoconjugates. To retain their functions, we explored methods to protect 211At-immunoconjugates from oxidation and enhance their stability. Among several other reducing agents, sodium ascorbate most safely and successfully protected 211At-labeled trastuzumab from oxidative stress and retained the stability of the 211At-labeled antibody and its cytotoxicity against antigen-expressing cells for several days.

We developed a positron emission tomography (PET) system for multiple-isotope imaging. Our PET system, named multiple-isotope PET (MI-PET), can distinguish between different tracer nuclides using coincidence measurement of prompt gamma-rays, which are emitted after positron emission. In MI-PET imaging with a pure positron emitter and prompt-gamma emitter, because of the imperfectness of prompt gamma-ray detection, an image for a pure positron emitter taken by MI-PET is superposed by a positron-{\gamma} emitter. Therefore, in order to make isolated images of the pure positron emitter, we developed image reconstruction methods based on data subtraction specific to MI-PET. We tested two methods, subtraction between reconstructed images and subtraction between sinogram data. In both methods, normalization for position dependence of the prompt {\gamma}-ray sensitivity is required in addition to detector sensitivity normalization. For these normalizations, we performed normalization scans using cylindrical phantoms of the positron-gamma emitters Sc-44m and Na-22. A long period measurement using the activity decay of Sc-44m (Half-life 58.6 hours) elucidated that the acquisition ratio between the prompt gamma-rays coincided with PET event and pure PET event changes on the basis of object activities. Therefore, we developed a correction method that involves subtraction parameters dependent on the activities, i.e., the counting rate. From analysis of dual-tracer phantom images, data subtraction in the sinogram data with sensitivity correction gives a higher quality of isolated images for the pure positron emitter than those from image subtractions. Furthermore, from dual-isotope (F-18-FDG and Sc-44m) mouse imaging, we concluded that our developed method can be used for practical imaging of a living organism., Comment: 17 pages, 12 figures

Activation cross sections of the medically interesting radionuclide

The aim of this study was to identify relevant Rf chemical species by using reversed-phase extraction chromatography with 2-thenoyltrifluoroacetone (TTA) resin as the stationary phase. Because TTA can be used to extract specific metal ions, the distribution ratios of the system enabled determination of the specific complex formation constant of Rf. We performed several experiments on chemical systems with Zr, Hf, No, and Rf, determined their adsorption coefficients, and deduced the K d values for Rf.

The production of 117mSn by charged-particle induced reactions is an interesting topic for medical application. Production cross sections of α-induced reactions on natIn for 117mSn up to 50 MeV were measured using the stacked foil technique and activation method. The integral yield of 117mSn was estimated using the measured cross sections. The results were compared with experimental data investigated earlier and theoretical calculation. Measured cross sections for 113Sn and 116m,117,118mSb isotopes were also presented.

Activation cross sections for deuteron-induced reactions on natural palladium were measured up to 24 MeV using the stacked-foil method and the high resolution gamma-ray spectroscopy. The production cross sections of 103Ag, the parent of a medical radioactive isotope 103Pd, were obtained. We found that our result is in good agreement with the previous data up to 20.3 MeV, and obtained new data at higher energies. In addition, the production cross sections of 104g+mAg, 105Ag, 106mAg, 110mAg and 111Ag were presented.

We have studied extraction behavior of group-6 elements Mo and W to search for suitable conditions for an on-line extraction experiment of their heavier homolog, seaborgium (Sg). Batch-wise extraction of carrier-free radiotracers 93mMo and 177,179,181W were carried out from 0.10 – 8.6 M H2SO4 and 1.0 × 10−4 − 5.0 M HF/1.0 M HCl into toluene with a quaternary ammonium compound, Aliquat336. Anionic sulfate complexes of Mo and W with charge − 2 were extracted with Aliquat336 from H2SO4 solutions with concentrations of [H2SO4] > 2 M. In HF/1.0 M HCl, oxyfluoro complexes of Mo and W with charge − 1 were interpreted to be formed and extracted with Aliquat336. From these results, favorable conditions for the extraction of Sg are discussed.

The excitation functions of deuteron-induced reactions on 169Tm were measured using the stacked-foil method and high resolution gamma-ray spectrometry. The production cross sections of a medical radionuclide 169Yb were investigated. The result was compared with the previous experiments and found to be in good agreement. In addition to 169Yb, the production cross sections of Tm isotopes, 170Tm, 168Tm and 167Tm, were measured. These results were compared with the TALYS calculations taken from the TENDL-2015 online data library.

Activation cross sections of the deuteron-induced reactions on natural zinc are studied for the production of the medical radionuclide

A gas-phase chemical study of rhenium carbonyls was carried out using short-lived radioisotopes produced at a heavy-ion accelerator. The Re isotopes produced in the nuclear reactions of natGd(23Na,xn)172–177Re were pre-separated with a gas-filled recoil ion separator and their carbonyls were synthesized in a mixture of inert gas and carbon monoxide. Using a low temperature isothermal chromatography apparatus, the adsorption enthalpies of Re carbonyls were derived to be ΔHads = −42 ± 2 kJ mol−1 on a Teflon® surface by fitting the external chromatograms with a Monte Carlo simulation program. A chemical yield of 25% relative to that of the transport yield for Re by a He/KCl gas-jet was achieved. The laser-ablation time-of-flight mass-spectrometric technique was employed to identify the species of Re carbonyls produced in the gas phase. The most stable species was deduced to be Re(CO)5 based on the mass-spectrometric analysis as well as quantum chemistry calculations.

Activation cross sections of the medically interesting radionuclide 45Ti were investigated in the deuteron-induced reaction on 45Sc. 45Ti can be produced in a radioactive-contamination-free form in the 45Sc(d,2n)45Ti reaction below 15 MeV deuteron energy. The stacked foil activation technique and γ-ray spectrometry were used to determine the cross sections. The physical yield of 45Ti was deduced from the measured cross sections.

$^{117m}$Sn is one of the radioisotopes can be beneficially produced through alpha particle irradiation. The targets were prepared by deposition of $^{116}$Cd metal onto high purity 12 $\mu$m thick Cu backing. The average deposited thickness was 21.9 $\mu$m. The beam energy was thoroughly measured by Time of Flight (TOF) methods and proved to be 51.2 MeV. For the experiment the well-established stacked foil technique was used. In addition to the Cd targets, Ti foils were also inserted into the stacks for energy and intensity monitoring. The Cu backings were also used for monitoring and as recoil catcher of the reaction products from the cadmium layer. The activities of the irradiated foils were measured with HPGe detector for gamma-ray spectrometry and cross section values were determined. As a result excitation functions for the formation of $^{117m}$Sn, $^{117m,g}$In, $^{116m}$In, $^{115m}$In and $^{115m,g}$Cd from enriched $^{116}$Cd were deduced and compared with the available literature data and with the results of the nuclear reaction model code calculations EMPIRE 3.2 and TALYS 1.8. Yield curves were also deduced for the measured nuclear reactions and compared with the literature.

The cross sections of alpha particles induced nuclear reactions on natural germanium were investigated by using the standard stacked foil target technique, the activation method and high resolution gamma spectrometry. Targets with thickness of about 1 mu m were prepared from natural Ge by vacuum evaporation onto 25 mu m thick polyimide (Kapton) backing foils. Stacks were composed of Kapton-Ge-Ge-Kapton sandwich target foils and additional titanium monitor foils with nominal thickness of 11 mu m to monitor the beam parameters using the Ti-nat(alpha,x)Cr-51 reaction. The irradiations were done with E-alpha = 20.7 and E-alpha = 51.25 MeV, I-alpha = 50 nA alpha particle beams for about 1 h. Direct or cumulative activation cross sections were determined for production of the Se-72,Se-73,Se-75, (71,72,74,76,78)AS and Ge-69 radionuclides: The obtained experimental cross sections were compared to the results of theoretical calculations taken from the TENDL data library based on the TALYS computer code. A comparison was made with available experimental data measured earlier. Thick target yields were deduced from the experimental cross sections and compared with the data published before.

The excitation functions were measured for the (nat)Cu(α,x)(66,67)Ga,(65)Zn,(57,58,60)Co reactions in the energy range of 16.5 -50MeV. A conventional stacked-foil activation technique combined with HPGe γ-ray spectrometry was employed to determine cross-sections. The measured cross-sections were critically compared with relevant previous experimental data and also with the evaluated data in the TENDL-2014 library. Present results confirmed some of the previous experimental data, whereas only a partial agreement was found with the evaluated data. The measured data are useful for reducing the existing discrepancies in the literature, to improve the nuclear reaction model codes, and to enrich the experimental database towards various applications.

We successfully observed the equilibrium state of the chemical reactions for superheavy elements on a one-atom-at-a-time scale; we investigated the time dependence of the extraction behaviour of element 104, Rf. The distribution coefficient of Rf in 9 M HCl was found to be higher than those of its homologous elements, probably due to differences in the chloride complexation of Rf.