[en] We report on the remarkable property of silver exchanged zeolites to efficiently adsorb radon at room temperature. We investigated three commercially available zeolite materials and compared their adsorption performance to commonly available activated carbons by measuring ²²²Rn breakthrough curves under different experimental conditions. Depending on the type of carrier gas and gas velocity, dynamic adsorption factors k were found to be at least two orders of magnitude higher for zeolite materials as compared to activated carbons. Moisture control was found to be crucial for effective ²²²Rn adsorption since water has shown to exhibit a strong competitive effect. This contribution will present experimental results obtained from systematic investigations involving the practical usage of these materials. It is shown that more compact and economic room-temperature ²²²Rn adsorption systems can be designed using silver exchanged zeolites considerably reducing the impact of ²²²Rn originating from ²²⁶Ra emanations in environmental, scientific and industrial applications

[en] The interest in ⁸⁹Zr radioisotopes is increasing in the last years due to its half-life that allows to label biomolecules, such as monoclonal antibodies, for pharmacokinetic studies and clinical trials to trace slow biological process. Due to the availability of the target material in natural form, the ⁸⁹Y(p,n)⁸⁹Zr is considered the best nuclear reaction for the production of ⁸⁹Zr in medical cyclotrons. Nowadays, the design and manufacturing of appropriate cyclotron solid targets for the production of large amounts of ⁸⁹Zr with high specific activity remain a technological challenge. The LNL-INFN group, in the framework of the LARAMED (laboratories for radioisotopes of medical interest) project, has developed two methods for ⁸⁹Y targets realization for the production of ⁸⁹Zr. The targets have been tested in collaboration with IRCCS Sacro Cuore-Don Calabria Hospital in Negrar (VR). The first proposed method is Magnetron Sputtering (MS) deposition of yttrium material directly onto niobium backing (chosen due to its chemical inertness). MS is a physical vapour deposition technique that takes place in a vacuum by means of inert gas plasma (Ar). The material of interest is attached to the cathode, and plasma is created when a difference of potential is applied between the cathode and the substrate (anode). The positive ions of the inert gas are accelerated towards the cathode. When the ions collide with the atoms of the sputtering target, the energy transfer causes the detachment of some atoms, which are then deposited on the substrate. Magnetron sputtering is characterized by elevated plasma utilization efficiency thanks to its magnetic confinement.

[en] The great advancement of nuclear medicine (NM) held in the last decades mainly relies in the development and use of a wide range of different and more effective radiopharmaceuticals. This goal has been achieved by combining the biological behaviour of new ligand molecules, selective for the specific tumour target, and the main nuclear properties of novel radioisotopes, specific for diagnostic, therapy and theranostic applications. The use and availability of a variety of radionuclides has experienced a great development as a result of the increase of technologies related to their production, even based on cyclotrons. At INFN-LNL a BEST 70p high performance cyclotron was installed in 2015, to be dedicated not only to the new frontiers of nuclear physics studies (SPES project), but also to the interdisciplinary and medical physics investigations, through the LARAMED project, acronym for LAboratory of RADionuclides for MEDicine. Albeit the facility is currently under development (installation of beam-lines, laboratories etc), since 2012 the team started working on the production of conventional and innovative radionuclides for NM applications. LARAMED activities have started with TECHN-OSP and APOTEMA projects, aimed at the direct production of Tc-99m with small cyclotrons already installed in hospitals. The focus is now devoted on studying new emerging radionuclides such as Cu-67 (COME project), Sc-47 (PASTA project) and Mn-52 (METRICS project). These studies have allowed the development of new techniques for producing thin solid targets by using High Energy Vibrational Powder Plating (HIVIPP) method (E- PLATE project) and high-power target (TERABIO premium-project). The collaboration with NM radiopharmacies holding a PET cyclotron (e.g. the Sant’Orsola Hospital in Bologna and the Sacro Cuore Don Calabria Hospital in Negrar), as well as with national and international research institutes, such as several INFN sections, the University of Ferrara, the CNR in Milan and the ARRONAX facility (Nantes, France), made all this effort possible. An up-dated overview of the on-going projects regarding different radiometals, produced by using proton cyclotrons, is the purpose of this poster. Results from cross-section measurements, target production, irradiation runs, target processing and recovery, that was carried out by the LARAMED research group will be presented. (author)

[en] Cyclotron solid target realization is often crucial for radioisotope production. A set of most standard techniques for target preparation is often inefficient for the refractory metals, like Ti, Mo, W, Zr. In the case of enriched isotopes, a technique that causes minimal material losses is absolutely essential. The High Energy Vibrational Powder Plating (HIVIPP) method, based on the motion of material powders in an electric field, provides a solution to minimize losses and deposition of “problematic” refractory metals. The deposition process is carried out in a vacuum inside a quartz cylinder with electrodes mounted at its top and bottom. A high voltage (>2 kV) applied to the electrodes causes the powder motion towards the electrode of the opposite charge on which particles are deposited. The HIVIPP method allows preparation of targets with areal densities ranging from μg/cm2 up to mg/cm2, with a very high yield and of excellent thickness homogeneity, superior to the one obtained by conventional evaporation. In order to guarantee a reliable and reproducible application of the HIVIPP method for other enriched materials, a deep study of the process is required. The “E-PLATE: Electrostatic Powder Plating for Accelerator Targets” project of INFN (2018-2019) is devoted to R&D on HIVIPP technique aimed to depose optimization and overcoming thickness limitation (evident from previous works of I. Sugai). This is done to allow the preparation of the targets as for nuclear cross-section measurements (program-minimum), as for medical radionuclides production (program-maximum).

[en] ⁴⁷Sc is an emerging theranostic radionuclide included in the CRP No. F22053 by the IAEA, together with ⁶⁷Cu and ¹⁸⁶Re. The long half-life of ⁴⁷Sc (about 3.35 days) is suitable to follow the slow biodistribution of monoclonal antibodies and large molecules, while its β- and γ radiation are useful to deliver cytotoxic dose to small medium size tumours and to perform SPECT imaging studies to select patient prior therapy. In addition, ⁴⁷Sc can be paired to β+ emitters such as ⁴⁴Sc or ⁴³Sc to perform low-dose PET with the same radiopharmaceutical, to tailor the dose to the specific patient before therapy. The critical issue in the use of ⁴⁷Sc is the lack of availability in sufficient quantities and at a reasonable cost. In the framework of the LARAMED program, the PASTA project (acronym of Production with Accelerator of Sc-47 for Theranostic Applications) was funded at INFN-LNL. The goal of the PASTA project is to measure several nuclear cross sections, comparing them with previous experimental data and theoretical predictions, in order to find out the best irradiation conditions for ⁴⁷Sc production.

[en] Multimodality imaging is a diagnostic technique that combines morphological and functional information for improving the power of current imaging methods. PET or SPECT with CT are currently the most popular multimodal imaging technologies in this field while the combination of PET or SPECT with MRI (magnetic resonance imaging) is a newly-established technology. This multimodal technology usually involves the use of two different compounds, a contrast agent for MRI (i.e. Gadolinium-based molecules) and a radioactive tracer for PET/SPECT, generating a mismatch in the diagnostic information content. In this regard, we want to investigate the possibility and the effect of having a molecular fusion between PET and MRI by using a bimodal probe, a molecule able to be detected by both techniques. The same compound will act as a contrast and as a radioactive agent, preserving both the paramagnetic and nuclear characteristics. Manganese is the only transition element having paramagnetic properties suitable for MRI and two manganese isotopes, ⁵²Mn and ⁵¹Mn, positron emitters that could be employed as PET tracers. The scope of the METRICS project (METRICS: Multimodal pET/mRi Imaging with Cyclotron-produced ^52/51Mn iSotopes), funded by INFN (CSN5 2018–2020), aims to develop a perfect molecular matching between PET and MRI using paramagnetic and radioactive manganese isotopes to afford an unprecedented type of PET/MRI hybrid imaging and to develop the technology, target, and separation module to self-produce by cyclotron the ^51/52Mn. So far, natural chromium targets have been successfully produced and tested under a proton beam up to 50 μA (~ 1 kW) for thermomechanical tests, manganese paramagnetic complexes have been synthesized and characterized, while dosimetric studies and Cr/Mn radiochemical separation are currently under development. In this work we present the preliminary results of the METRICS project. The possible efficacy of having a real molecular fusion between PET and MRI by using a new bimodal probe, based on the use of manganese paramagnetic complexes, labelled with ^51/52Mn radionuclides will be underlined. (author)

[en] ^99mTc (T1/2=6.06 h, Eγ =140 keV (89%)) is the most used radionuclide worldwide for Single Photon Emission Computed Tomography scans (SPECT). It is commonly obtained from the decay of its parent nuclide ⁹⁹Mo (T1/2=66 h), by eluting compact and transportable ⁹⁹Mo/^99mTc generator systems that makes it available directly in nuclear medicine departments. The majority of ⁹⁹Mo is produced in a few ageing nuclear reactors around the world, using highly enriched uranium (HEU) targets. The unexpected worldwide Technetium-99m (t1/2=6h, Eγ=140keV) shortening occurred on the radioisotope market in 2009-2010, due to the reactor produced parent nuclide ⁹⁹Mo production crisis. It has prompted new ideas about alternative production routes of this important gamma emitter radionuclide used in 85% of diagnostic nuclear medicine procedures. In the framework of INFN-funded (National Scientific Committees 5-CSN5, (2012-2017) research programs APOTEMA/TECHN-OSP, and of a Coordinated Research Project (CRP Code: F22062) promoted by the International Atomic Energy Agency (IAEA), we developed in collaboration with other Italian Universities and Research Institutions, a technology to produce GBq amount of ^99mTc by the existing medical cyclotron network in Italy, through the (p,2n) nuclear reaction on a ¹⁰⁰Mo enriched metal target.

[en] Highlights: • Nb–Ta, Nb–Zr and Ta–Zr alloy films were deposited by co-sputtering. • Co-sputtered Nb–Zr and Nb–Ta alloy coatings had crystalline microstructures. • Diffusion barrier efficiency of Nb–Zr and Nb–Ta decreased with the increase of Nb %. • Co-sputtered Ta–Zr films with 30–73 at.% Ta were amorphous. • Sputtered amorphous Ta–Zr films showed superior diffusion barrier efficiency. - Abstract: Protective corrosion resistant coatings serve for decreasing the amount of ionic contaminants from Havar® entrance foils of the targets for ["1"8F] production. The corrosion damage of coated entrance foils is caused mainly by the diffusion of highly reactive products of water radiolysis through the protective film toward Havar® substrate. Since amorphous metal alloys (metallic glasses) are well-known to perform a high corrosion resistance, the glass forming ability, microstructure and diffusion barrier efficiency of binary alloys containing chemically inert Nb, Ta, Zr were investigated. Nb–Ta, Nb–Zr and Ta–Zr films of different alloy composition and ∼1.5 μm thickness were co-deposited by magnetron sputtering. Diffusion barrier efficiency tests used reactive aluminum underlayer and protons of acid solution and gallium atoms at elevated temperature as diffusing particles. Though co-sputtered Nb–Ta and Nb–Zr alloy films of different contents were crystalline, Ta–Zr alloy was found to form dense amorphous microstructures in a range of composition with 30–73% atomic Ta. The diffusion barrier efficiency of Nb–Zr and Nb–Ta alloy coatings decreased with increase of Nb content. The diffusion barrier efficiency of sputtered Ta–Zr alloy coatings increased with the transition from nanocrystalline columnar microstructure to amorphous for coatings with 30–73 at.% Ta

[en] The goal of PASTA project (acronym for production with accelerator of ⁴⁷Sc for theranostic applications) is the determination of excitation functions associated to several nuclear reactions, aimed at yielding the theranostic radionuclide ⁴⁷Sc. This work reports the main results obtained by irradiating natural vanadium targets with proton beams up to 70 MeV. Particular care is also given to the co-production of ⁴⁶Sc, the only isotopic contaminant with half-life longer than ⁴⁷Sc. Experimental results are compared with theoretical studies by means of known nuclear reaction software tools that are publicly available.

[en] Chemically inert coatings on Havar"® entrance foils of the targets for ["1"8F] production via proton irradiation of enriched water at pressurized conditions are needed to decrease the amount of ionic contaminants released from Havar"®. During current investigation, magnetron sputtered niobium and niobium oxide were chosen as the candidates for protective coatings because of their superior chemical resistance. Aluminated quartz substrates allowed us to verify the protection efficiency of the desirable coatings as diffusion barriers. Two modeling corrosion tests based on the extreme susceptibility of aluminum to liquid gallium and acid corrosion were applied. As far as niobium coatings obtained by magnetron sputtering are columnar, the grain boundaries provide a fast diffusion path for active species of corrosive media to penetrate and to corrode the substrate. Amorphous niobium oxide films obtained by reactive magnetron sputtering showed superior barrier properties according to the corrosion tests performed. In order to prevent degrading of brittle niobium oxide at high pressures, multilayers combining high ductility of niobium with superior diffusion barrier efficiency of niobium oxide were proposed. The intercalation of niobium oxide interlayers was proved to interrupt the columnar grain growth of niobium during sputtering, resulting in improved diffusion barrier efficiency of obtained multilayers. The thin layer multilayer coating architecture with 70 nm bi-layer thickness was found preferential because of higher thermal stability. - Highlights: • Diffusion barrier efficiency of niobium, niobium oxide and their multilayers was studied. • The intercalation of niobium oxide layers interrupted the columnar grain growth of niobium. • The bilayer architectures influenced the stability of the multilayer coatings. • The thin layer multilayer coating with 70 nm double-layer was found superior.