The evaporation behaviour of tellurium from liquid lead–bismuth eutectic was investigated using the transpiration method in an inert atmosphere between 220 and 600 °C. The results showed a significant retention of Te within the LBE matrix compared to the vapour pressure of pure Te. The temperature dependence of the Henry’s law volatility constant above 350 °C was determined using data from this study and compared with data reported in the literature. A noticeable deviation from linearity was observed at temperatures below 350 °C, possibly due to surface enrichment phenomena connected to chemical reactions enhancing Te volatilisation, highlighting the need for further investigation at lower temperatures.

The AGGIE gas-filled separator has been installed at the Cyclotron Institute at Texas A&M University and is now in routine use. Named Albert Ghiorso's Gas-filled Ion Equipment and formerly known as SASSY II and later SASSYER, the separator has a DvQhDv configuration and is currently used for nuclear reaction studies and online chemistry experiments. This manuscript describes the separator and experiments to measure its transmission, which was found to be approximate to 22% using the 164Dy(40Ar, xn)204-xPo reactions. Additionally, an investigation into AGGIE's ability to measure beam luminosity with a new, diamond detector was performed. The response of the diamond detector was characterized relative to the traditionally used silicon detector. The diamond detector was found to be overall suitable for luminosity measurements with a notable improvement in radiation hardness as evaluated based on the centroid, spectroscopic resolution and count rate of the implanting ions, thus minimizing potential for downtime while replacing detectors during an irradiation.

Radiocesium is a volatile fission product of high radiological relevance in nuclear release scenarios, yet its retention and potential release from lead-based reactor coolants remain poorly understood due to the lack of reliable thermodynamic data. In this work, radioactive 134Cs was used as a tracer to quantitatively determine the Henry’s Law constant governing cesium evaporation from liquid lead and lead–bismuth eutectic over a broad temperature range. Measurements were performed using a gas-phase transpiration method at dilute (Henry-regime) concentrations consistent with predicted cesium inventories in lead-based reactor coolants, enabling the direct use of derived thermodynamic data in source-term and release modeling. The resulting temperature-dependent constants reduce key uncertainties in predicting radiocesium release during incidents, such as fuel pin failure, in heavy liquid metal-cooled reactors. In addition to providing model parameters, the study identifies impurity‑driven speciation effects that may strongly influence cesium mobilization under off‑normal conditions. Overall, the work provides high-quality, experimentally constrained thermodynamic inputs required for more quantitative assessment of radiocesium release potential and associated radiological impact.

Abstract Tellurium (Te) volatilization from lead–bismuth eutectic (LBE) was investigated by thermosublimatography to resolve the chemical form of Te transported from a Pb-rich liquid metal and its subsequent surface-mediated transformations. For dilute Te in LBE (xTe ≈ 10–3), the dominant transported species was assigned to PbTe(g), which deposited at high temperature in both fused-silica and 316L stainless-steel columns. This indicates that lead-based coolants intrinsically suppress Te release, as Te bound in PbTe is less volatile than elemental Te. In fused-silica columns, deposited PbTe partially decomposed under more oxidizing carrier-gas conditions, causing secondary release and low-temperature deposition of elemental Te, most consistently explained by Te2(g) formation. In contrast, PbTe remained stable on 316L stainless-steel surfaces even under water-saturated conditions, consistent with local redox buffering by the steel surface. These results demonstrate that Te transport from Pb-rich liquid metal is governed not only by its chemical form, but also by gas-phase conditions and surface-mediated processes. The findings provide insight into chalcogen transport at liquid metal/material interfaces and demonstrate how surface selection and carrier-gas redox conditions can influence Te mobility.

Isothermal vacuum adsorption chromatography (IVAC) in the molecular-flow regime offers the speed and chemical selectivity needed to study superheavy elements beyond flerovium (Fl, Z = 114). In this study, the GLACIER buffer gas cell and RF quadrupole combination was coupled with IVAC behind the gas-filled separator AGGIE for benchmark experiments with short-lived mercury radioisotopes 179Hg (t 1/2 = 1.05(3) s) and 178Hg (t 1/2 = 0.2665(24) s). GLACIER provided stable transport conditions over multiple days thereby enabling a clean chromatographic separation of Hg from less-volatile nuclear reaction byproducts on fused silica. These experiments validated the employed microscopic-kinetic transport model at zero surface coverage implemented in the form of a Monte Carlo simulation. The presented findings render this approach applicable to superheavy elements such as moscovium (Mc, Z = 115).

Auger-electron emitters have steadily acquired considerable attention in the last decade due to their potential to treat micrometastases. However, the limited availability of Auger-electron emitters has restricted investigations of the radiobiological effects induced by Auger cascades. Among the medically relevant Auger-electron-emitting radiolanthanides, 161Ho stands out as a suitable candidate thanks to its high emission of low-energy electrons. Its low-intensity, low-energy γ rays would enable dosimetry evaluation, while minimizing the deposited dose.This project involved the measurement of proton-induced activation cross sections of holmium radioisotopes, focusing on 160m,161cum,162mHo, using nat,161,162Dy targets irradiated with an 18 MeV cyclotron at the Bern medical cyclotron laboratory. Additionally, production yields were measured at the Paul Scherrer Institute using a 72 MeV separated-sector cyclotron, where dysprosium targets were irradiated for the 161Ho direct production and 165Ho targets to study the indirect production pathway via 161Er decay.Comparison with previously published experimental data showed good agreement for the production cross sections of relevant holmium radioisotopes, while those of 160gHo were reported here for the first time. The nuclear reaction cross sections of 161cum,162 g,162mHo were determined by inverting a system of linear equations. Theoretical predictions from the TENDL 2023 library generally overestimated the experimental excitation functions by up to 50%. Irradiation runs of production targets validated the cross sections measured. 165Ho emerged as optimal target material for large-scale production of highly radionuclidically pure 161Ho. Six-hour irradiation of 165Ho targets yielded 15 GBq of 161Er’s end-of-bombardment activity at up to 99.98% of radionuclidic purity using 45 MeV proton beams.

This study provides insights into the formation of Tb/Pd films produced by electroplating in combination with the so-called coupled reduction technique. The use of 149Tb as an α-emitting radionuclide enabled for the first time the study of the distribution of Tb across the surface and along the thickness of the Pd bulk by means of radiography and α-spectroscopy combined with Monte Carlo simulations of the energy loss of emitted α-particles, respectively. Additionally, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy were employed for surface analysis, whereas X-ray diffraction provided conclusive evidence of the formed crystalline phases. The obtained results indicate the formation of either the intermetallic phase TbPd3 or a Tb/Pd solid solution, depending on the heating time and temperature as well as the local Tb/Pd atomic ratio. These insights pave the way to the production of stable targets for heavy ion-beam irradiations as well as other applications.

Pd-Gd samples, intended as model of target materials for nuclear physics experiments, were produced via molecular plating followed by coupled reduction. Using high-resolution X-ray diffraction, performed with a highly focused X-ray beam at the Swiss Light Source, at the Paul Scherrer Institute, the formation of single intermetallic GdPd3 compounds dispersed within a Pd-Gd solid solution were identified. A homogeneous distribution of Gd was detected throughout the thickness of the samples. The micro-scale analysis provided detailed insights into the phase composition and elemental distribution, revealing that due to the low Gd concentration used, the bulk structure is likely predominantly a Pd-Gd solid solution with uniformly dispersed intermetallic domains, rather than a complete intermetallic single phase. Additionally, Gd-aggregated regions were observed at the samples surface, where µ-XPS measurements revealed the presence of Gd(III), most probably in the form of Gd2O3. This study suggests that previously reported ’intermetallic targets’ were not pure intermetallic compounds and offers design insights for future target manufacturing with similar materials. Furthermore, this study highlights the advantages of using high-resolution micro-characterization techniques.

This study investigates the evaporation and deposition of iodine from lead–bismuth eutectic (LBE) systems with iodine mole fractions of 10–5 to 10–3, crucial for the safety of LBE-cooled nuclear reactors. Combining thermosublimatography, morphological analysis and thermodynamic calculations, it identifies PbI2 and BiI3 as the two primarily deposited species, while revealing BiI disproportionation. This work provides novel insights into iodine speciation, emphasizing its importance for the safety of LBE-cooled reactors and gives input for advancing experimental setups and modeling approaches for complex nuclear systems.

In the field of superheavy element chemistry, the study of the chemical properties of nihonium (Nh, Z = 113) is currently in the focus. To chemically characterize Nh, fast gas-phase chemistry experiments are essential. Hereto, a new thermochromatographic detection system named LEGEND has been developed for chemistry experiments behind the gas-filled recoil separators SHANS/SHANS2. The presented system will be further developed to higher starting point temperatures of the negative temperature gradient, thereby enabling the investigation of less volatile chemical species. A recoil transfer chamber with a vacuum window acts as an interface between the separator and the thermochromatography detector array, whereas a gas circulation and purification system ensures the required high gas purities. Finally, a state-of-the-art data acquisition system allows for event-by-event alpha-particle and spontaneous fission fragment spectroscopy. The measurement efficiency of detecting alpha-particles adsorbed on the active surface is 89.1%. Using the nuclear fusion-evaporation reactions 169 Tm( 40 Ar, x n) 204-206 Fr and 153 Eu( 40 Ar, x n) 184-185 Tl, short-lived radioisotopes 205 Fr ( t 1 /2 = 3.92 s) and 185 Tl ( t 1/2 = 1.93 s) were produced for first online experiments behind SHANS. The herein presented results render the LEGEND system suitable for gas adsorption chromatography experiments with short-lived 284 Nh ( t 1/2 approximate to 0.77 s).

The Paul Scherrer Institut (PSI) is the largest research institute for natural and engineering sciences in Switzerland, focusing on cutting-edge research in four fields, namely, Future Technologies, Energy and Climate, Health Innovation and Fundamentals of Nature. PSI develops, builds and operates complex large research facilities, in particular, one of the most powerful proton accelerators worldwide. An important component of innovative radiopharmaceuticals, especially in oncology, is the availability of various radionuclides with optimal decay properties for the improvement of diagnostic or therapeutic efficacy. The Laboratory od Radiochemistry (LRC) at PSI, in collaboration with the Center of Radiopharmaceutical Sciences (CRS), produces and further develops a variety of accelerator, reactor (or Spallation Neutron Source) and spallation-induced radionuclides via its vast networks. Medical radionuclides must be available with high-specific activity and purity. Here, the choice of nuclear reaction and subsequent radiochemical isolation strategy play a key role.

Terbium-149 (T1/2 = 4.1 h, Eα = 3.98 MeV (16.7%), 28 µm range in tissue) is a radionuclide with potential for targeted alpha therapy. Due to the negligible emission of α-emitting daughter nuclides, toxicity to healthy tissue may be reduced in comparison with other α-particle emitters. In this study, terbium-149 was produced via 1.4 GeV proton irradiation of a tantalum target at the CERN-ISOLDE facility. The spallation products were mass separated and implanted on zinc-coated foils and, later, radiochemically processed. Terbium-149 was separated from the co-produced isobaric radioisotopes and the zinc coating from the implantation foil, using cation-exchange and extraction chromatographic techniques, respectively. At the end of separation, up to 260 MBq terbium-149 were obtained with > 99% radionuclidic purity. Radiolabeling experiments were performed with DOTATATE, achieving 50 MBq/nmol apparent molar activity with radiochemical purity > 99%. The chemical purity was determined by inductively coupled plasma–mass spectrometry measurements, which showed lead, copper, iron and zinc only at ppb level. The radiolabeling of the somatostatin analogue DOTATATE with [149Tb]TbCl3 and the subsequent in vivo PET/CT scans conducted in xenografted mice, showing good tumor uptake, further demonstrated product quality and its ability to be used in a preclinical setting.

Introduction: Targeted Radionuclide Therapy is used for the treatment of tumors in nuclear medicine, while sparing healthy tissues. Its application to cancer treatment is expanding. In particular, Auger-electron emitters potentially exhibit high efficacy in treating either small metastases or single tumor cells due to their short range in tissue. The aim of this paper is to study the feasibility of a large-scale production of thulium-167, an Auger-electron emitter radionuclide, in view of eventual systematic preclinical studies.Methods: Proton-irradiated enriched erbium-167 and erbium-168 oxides were used to measure the production cross sections of thulium-165, thulium-166, thulium-167, and thulium-168 utilizing an 18-MeV medical cyclotron equipped with a Beam Transport Line (BTL) at the Bern medical cyclotron laboratory. The comparison between the experimental and the TENDL 2021 theoretical cross-section results were in good agreement. Additional experiments were performed to assess the production yields of thulium radioisotopes in the BTL. Thulium-167 production yield was also measured irradiating five different target materials (167Er2O3, 168Er2O3, natTm2O3, natYb2O3, 171Yb2O3) with proton beams up to 63 MeV at the Injector II cyclotron of Paul Scherrer Institute.Results and Discussion: Our experiments showed that an 8-h irradiation of enriched ytterbium-171 oxide produced about 420 MBq of thulium-167 with a radionuclidic purity of 99.95% after 5 days of cooling time with a proton beam of about 53 MeV. Larger activities of thulium-167 can be achieved using enriched erbium-168 oxide with a 23-MeV proton beam, obtaining about 1 GBq after 8-h irradiation with a radionuclidic purity of <99.5% 5 days post end of bombardment.

We report on the irradiation of a modified silica-filled room temperature vulcanized (RTV) PDMS. The irradiation experiments were conducted in air with combined neutron (approx. 6 center dot 10(12) n center dot cm(-2)center dot s(-1) at energies 1 meV to 1 MeV with an approximated maximum of 3% tail towards higher energy neutrons from 1 MeV up to 100 MeV) and gamma rays (739-28,900 Gy at energies 0.01 MeV to 50 MeV) in the NAA position in the Swiss Spallation Neutron Source SINQ. Softening of the gel prevailed for the shorter exposures, hardening for the longer exposures within the explored range of exposure time (1.5 to 47 min). The material changes were sensed using dynamic mechanical analysis (DMA), analysis of the swelling in good solvents (o-, m-, p- xylene), Raman and FTIR spectroscopy, and water contact angle measurement. While the irradiation of PDMS influenced the swelling in the xylenes, melting temperature and elastic modulus, it did not discernibly influence the Raman and FTIR spectra, sol content, and water contact angle. Irradiation can be used as a post treatment of PDMS items enabling the optimization of elastic modulus and swelling characteristics.

During recent online gas-phase experiments with the transactinide elements copernicium (Cn, Z = 112) and flerovium (Fl, Z = 114), the transport of a volatile astatine species was observed. Comprehensive Monte Carlo simulations of the deposition pattern of At-211 on the given quartz, selenium, and gold chromatographic surfaces were carried out, and the corresponding adsorption enthalpies were estimated. Based on the astatine speciation from previous model experiments, the compound observed in this work was ascribed to AtOH/HAtO. The herein presented results assist in paving the way toward a future chemical characterization of tennessine (Ts, Z = 117) with similar gas adsorption chromatography techniques.

The Swiss Spallation Neutron Source SINQ of the Paul Scherrer Institute provides neutrons via proton-induced spallation reactions in a lead target. Produced neutrons are thermalized and impinge on 235U-targets, enclosed in a three-part chamber assembly, which is located in the inner wall of the SINQ shielding. The thermal-neutron-induced fission products can be readily transported from this chamber assembly to a radiochemical laboratory using the gas-jet technique either with a pure carrier gas or with an aerosol-particle-loaded carrier gas. In the past, mainly radioisotopes of the elements Se, Br, Rb, and Kr were retrieved and used for gas-phase chemistry experiments. Here, we present first experiments after the commissioning of the SINQ gas-jet facility as a source of recoverable, non-volatile and volatile, carrier-free fission products for general radiochemical studies and other applications.

Abstract A multi-target recoil chamber technique was applied to study online chemical properties of protactinium in chlorinating and brominating gas media using 226Pa (T 1/2 = 1.8 min) decaying by alpha emission (74%) and β+/EC decay (26%). A 58 MeV proton beam passing 15 × 50 μg/cm2 thick 232Th targets enabled production of 226Pa formed in the reaction 232Th(p,7n). Isothermal gas chromatography in quartz columns allowed for the determination of adsorption enthalpies of oxohalides and pure halides of Pa5+ compounds. On the basis of empirical correlations, these adsorption enthalpies (ΔH0 ads) could be converted to sublimation enthalpies (ΔH0 subl). Resulting values for the assumed compounds PaCl5, PaOCl3, PaBr5, and PaOBr3 were 113 ± 15, 329 ± 16, 165 ± 5 and 235 ± 17 kJ/mol, respectively. These values are rather similar to known ΔH0 subl data for group-5 elements Nb, Ta and Db in support of the assumption that Pa is a pseudo-group 5 element.

The efficient removal of the long-lived fission product 137 Cs from radioactive water by a filter material based on whey protein fibrils and activated carbon.