FP-CIT Research Articles

Photon Activation Analysis in Gallium, Nickel, and Vanadium

This research explored the development of the photonuclear production method of 67 Cu from 71 Ga as well as 47 Sc from 51 V. Both products serve as high-demand research medical radioisotopes. Furthermore, an understanding of these reactions is significant to fundamental nuclear physics and astrophysics. Bremsstrahlung flux was induced by an electron linac and a 1-mm tungsten radiator. Irradiation of gallium oxide powder, 98.78% pure 71 Ga, and a natural vanadium foil at 30.9 MeV and 100 W for 1 h produced 64.4 ± 0.4 Bq/W·s·kg of 67 Cu and 164 ± 3.1 Bq/W·s·kg of 47 Sc. A secondary irradiation with 99.6% pure 71 Ga and natural vanadium at 31.5 MeV and 100 W for 1.1 h produced 79.8 ± 0.9 Bq/W·s·kg of 67 Cu and 136 ± 7.2 Bq/W·s·kg of 47 Sc. The photoinduced activation is promising; however, further research into optimal geometry and power is required to maximize specific activity. Natural nickel was also irradiated to serve as a benchmark comparison. Effective cross sections for each reaction were inferred.

From crystal phase mixture to pure metal-organic frameworks – Tuning pore and structure properties

In this study, a sonochemical route for the preparation of a new Hf-MIL-140A metal–organic framework from a mixture of UiO-66/MIL-140A is presented. The sonochemical synthesis route not only allows the phase-pure MIL-140A structure to be obtained but also induces structural defects in the MIL-140A structure. The synergic effect between the sonochemical irradiation and the presence of a highly acidic environment results in the generation of slit-like defects in the crystal structure, which increases specific surface area and pore volume. The BET-specific surface area in the case of sonochemically derived Zr-MIL-140A reaches 653.3 m2/g, which is 1.5 times higher than that obtained during conventional synthesis. The developed Hf-MIL-140A structure is isostructural to Zr-MIL-140A, which was confirmed by synchrotron X-ray powder diffraction (SR-XRD) and by continuous rotation electron diffraction (cRED) analysis. The obtained MOF materials have high thermal and chemical stability, which makes them promising candidates for applications such as gas adsorption, radioactive waste removal, catalysis, and drug delivery.

A Two-Dimensional Non-Destructive Beam Monitoring Detector for Ion Beams

A two-dimensional beam monitoring detector named π2 has been developed and tested at the Bern University Hospital, using an 18 MeV proton beam provided by a medical cyclotron. This non-destructive device utilises a scintillating compound (P47 phosphor) coated onto a thin aluminium foil that is angled at 45∘ with respect to the beam axis. The scintillating light produced when the beam passes through the foil is captured by a CMOS camera, resulting in a two-dimensional image of the beam profile. Custom software is then used to analyse the image and extract valuable information about the beam’s position, shape, and intensity. The focus of the experimental work was on characterising the performance of the π2 with the 18 MeV proton beam. The linearity of the detector’s output signal was evaluated for proton fluxes ranging from 2·1010cm−2·s−1 to 5·1011cm−2·s−1. Furthermore, the beam profiles measured with the π2 were found to be consistent with reference measurements obtained using alternative beam monitors. Additionally, the experiments also involved studying the beam scattering caused by the foil and scintillating layer. Finally, in a long-term radiation test, the detector demonstrated a stable response up to an integrated proton flux of 3·1015cm−2. The π2 is currently being used at the Bern cyclotron for monitoring beams in the development of new methods for medical radioisotope production and for radiation hardness studies. The π2 has potential applications in several fields that involve the use of accelerated ions, such as cancer particle therapy, medical radioisotope production and radiation hardness studies.

Beam dynamics and space charge studies for the InnovaTron cyclotron

At IBA a high-intensity compact self-extracting cyclotron is being studied. There is no dedicated extraction device but instead, a special shaping of the magnetic iron and the use of harmonic coils to create large turn-separation. Proton currents up to 5 mA are aimed for. This would open new ways for large-scale production of medical radioisotopes. The main features of the cyclotron are presented. A major variable of the beam simulations is the space charge effect in the cyclotron centre. Using the SCALA-solver of Opera3D, we attempt to find the ion source plasma meniscus and the beam phase space and current extracted from it. With these properties known, we study the bunch formation and acceleration under high space charge condition with our in-house tracking code AOC. We also discuss a new tool that automates optimization of cyclotron settings for maximizing beam properties such as extraction efficiency.

Transparency - a patient-centric view on radiopharmaceutical extravasations.

Most radiopharmaceuticals are intravenously administered during nuclear medicine imaging or therapy procedures. When a nuclear medicine clinician delivers some or all of a radioactive drug into a patient's healthy tissue rather than the vein as intended, a patient experiences an extravasation. Radiopharmaceutical extravasations provide zero patient benefit and considerable potential downsides, depending on the severity of the extravasations. What nuclear medicine patients want and need regarding the administration of radiopharmaceuticals is transparency. And yet in the year 2023, little transparency exists regarding these extravasations. From the patient perspective, transparency regarding extravasations is essential to improving care, ensuring radiation protection, reducing health inequities, and untangling the deeply disturbing and irregular relationship between the nuclear medicine community and their regulating body, The U.S. Nuclear Regulatory Commission. Transparency is also critical to help address many other questions regarding radiopharmaceutical extravasations.

Neutronic simulation of medical radioisotope 99Mo and 177Lu production in IPR 14 MeV neutron generator facility

An accelerator based 14 MeV neutron generator is commissioned at Institute for Plasma Research India. The generator is based on the linear accelerator concept where the deuterium ion beam impinged to the tritium target to produce neutrons. The generator is designed to produce 5 × 1012 n/s (max.). The 14 MeV neutron source facilities are an emerging tool for the lab scale experiments and research. In order to utilize the generator for the welfare of humanity, the assessment is made for the production of medical radioisotopes using the neutron facility.The usage of radioisotopes in the treatment and diagnosis of a disease is an important factor in the healthcare sector. A series of calculations are conducted to generate radioisotopes, especially 99Mo and 177Lu those are having huge applications in the medical and pharmaceutical industries. 99Mo can be also generated through neutron reactions 98Mo(n, g)99Mo and 100Mo(n, 2n)99Mo apart from fission reaction. The cross section of 98Mo(n, g)99Mo is high in the thermal energy range whereas 100Mo(n,2n)99Mo occurs at a high energy range. 177Lu can be produced using the reactions 176Lu (n, g)177Lu and 176Yb (n, g)177Yb. The cross section of both 177Lu production routes is higher at thermal energy range. The neutron flux level near the target is around 1010 cm−2s−1. In order to enhance production capabilities, the neutron energy spectrum moderators are used to thermalize the neutrons. The materials used as a moderator are beryllium, HDPE, graphite, etc. Moderators enhance the capabilities of medical isotope production in neutron generators.

Dissolution of Molybdenum in Hydrogen Peroxide: A Thermodynamic, Kinetic and Microscopic Study of a Green Process for 99mTc Production.

99mTc-based radiopharmaceuticals are the most commonly used medical radioactive tracers in nuclear medicine for diagnostic imaging. Due to the expected global shortage of 99Mo, the parent radionuclide from which 99mTc is produced, new production methods should be developed. The SORGENTINA-RF (SRF) project aims at developing a prototypical medium-intensity D-T 14-MeV fusion neutron source specifically designed for production of medical radioisotopes with a focus on 99Mo. The scope of this work was to develop an efficient, cost-effective and green procedure for dissolution of solid molybdenum in hydrogen peroxide solutions compatible for 99mTc production via the SRF neutron source. The dissolution process was extensively studied for two different target geometries: pellets and powder. The first showed better characteristics and properties for the dissolution procedure, and up to 100 g of pellets were successfully dissolved in 250-280 min. The dissolution mechanism on the pellets was investigated by means of scanning electron microscopy and energy-dispersive X-ray spectroscopy. After the procedure, sodium molybdate crystals were characterized via X-ray diffraction, Raman and infrared spectroscopy and the high purity of the compound was established by means of inductively coupled plasma mass spectroscopy. The study confirmed the feasibility of the procedure for production of 99mTc in SRF as it is very cost-effective, with minimal consumption of peroxide and controlled low temperature.

Feasibility Study to Byproduce Medical Radioisotopes in a Fusion Reactor.

Currently, international nuclear fission reactors producing medical isotopes face the problem of shutdown and maintenance, decommissioning, or dismantling, while the production capacity of domestic research reactors for medical radioisotopes is inadequate, and the supply capacity for medical radioisotopes faces major challenges in the future. Fusion reactors are characterized by high neutron energy, high flux density, and the absence of highly radioactive fission fragments. Additionally, compared to fission reactors, the reactivity of the fusion reactor core is not significantly affected by the target material. By building a preliminary model of the China Fusion Engineering Test Reactor (CFETR), a Monte Carlo simulation was performed for particle transport between different target materials at a fusion power of 2 GW. The yields (specific activity) of six medical radioisotopes (14C, 89Sr, 32P, 64Cu, 67Cu, and 99Mo) with various irradiation positions, different target materials, and different irradiation times were studied, and compared with those of other high-flux engineering test reactors (HFETR) and the China Experimental Fast Reactor (CEFR). The results show that this approach not only provides competitive medical isotope yield, but also contributes to the performance of the fusion reactor itself, e.g., tritium self-sustainability and shielding performance.

Study of [formula omitted] reactions in the [formula omitted] targets

The development of novel medical radioisotopes for diagnostic and therapeutic purposes is critical for the advancement of personalized nuclear medicine. Radio metals contain promising theranostic pairs and can be used to label proteins and peptides. Scandium radionuclides have recently gained a lot of attention for their radiation characteristics (such as half-life, β particle and gamma emission energies) in order to improve the efficiency of medical care or therapeutic benefit for specific groups of patients.An accurate understanding of the production cross-sections is required to maximize the production yield and radionuclidic purity, as well as to improve the model predictions. In this paper, we report the measurement of the cross-section of (p,x) reactions for the production of 47Ca, 42K, 43K, and 44mSc, 46Sc, 47Sc, 48Sc using natCaO targets using proton beam of energy up to 60 MeV. The reported data for 47Sc is the first experimental data with a natCaO target in the 16–60 MeV energy range. All radioisotope cross sections produced by natCaO(p, x) reactions are compared to literature data and TALYS predictions.

Development of purification of no-carrier-added 47Sc of theranostic interest: selective separation study from the natTi(n,p) process

Abstract Scandium-47 is one of the most promising medical radioisotopes, and its production and trace separation make it an attractive candidate for theranostic application. In this study, the production of no-carrier-added (NCA) 47Sc through the natTi(n,p) reaction and subsequent purification using liquid–liquid extraction was done for the theranostic application. The comparative separation of NCA 47Sc after the dissolution of an activated Ti target using Di-2-Ethylhexyl Phosphoric Acid (HDEHP) in kerosene was evaluated. The extraction process was optimized in terms of the concentration of extractant, extraction time, pH, and reaction temperature to achieve the maximum possible separation. HDEHP is efficient and promising for rapid extraction and separation of NCA 47Sc from Ti ions at low acidity (pH 0.85) with high extraction percent (>99%), contaminated with 22.3% of Ti ions after 5 min of extraction time. Different stripping reagents were used to separate loaded 47Sc and Ti ions. Firstly, 5 M HCl was enough for stripping the loaded Ti ions. Then the loaded 47Sc was separated with a purity of 100% using 0.05 M NaOH. The obtained results find the HDEHP a promising extractant for efficient separation of 47Sc from irradiated Ti target for preparing the 47Sc radiopharmaceuticals for theranostics applications.

Novel solid target and irradiation methods for theranostic radioisotope production at the Bern medical cyclotron

The production of medical radioisotopes for theranostics is essential for the development of personalized nuclear medicine. Among them, radiometals can be used to label proteins and peptides and their supply in quantity and quality suitable for clinical applications represents a scientific challenge. A research program is ongoing at the Bern medical cyclotron, where an IBA Cyclone 18/18 HC is in operation. The cyclotron provides 18 MeV proton beams up to 150 μA and is equipped with a Solid Target Station (STS) and a 6 m Beam Transport Line (BTL), ending in a separate bunker with independent access. A novel magnetic target coin was realized to bombard isotope-enriched materials in the form of compressed powders, together with a compact focalization system to enhance the irradiation procedure. For an optimized production yield with the required radionuclidic purity, novel methods were developed to precisely measure the extracted beam energy and the involved reaction cross sections. In particular, a target station was realized to measure nuclear cross sections using materials in the form of powder deposited on an aluminium disc by sedimentation, bombarded by a monitored flat beam.

Feasibility study of laser-driven neutron sources for pharmaceutical applications

Abstract We predict the production yield of a medical radioisotope ${}^{67}$ Cu using ${}^{67}$ Zn(n, p) ${}^{67}$ Cu and ${}^{68}$ Zn(n, pn) ${}^{67}$ Cu reactions with fast neutrons provided from laser-driven neutron sources. The neutrons were generated by the p+ ${}^9\mathrm{Be}$ and d+ ${}^9$ Be reactions with high-energy ions accelerated by laser–plasma interaction. We evaluated the yield to be (3.3 $\pm$ 0.5) $\times$ 10 ${}^5$ atoms for ${}^{67}$ Cu, corresponding to a radioactivity of 1.0 $\pm$ 0.2 Bq, for a Zn foil sample with a single laser shot. Using a simulation with this result, we estimated ${}^{67}$ Cu production with a high-frequency laser. The result suggests that it is possible to generate ${}^{67}$ Cu with a radioactivity of 270 MBq using a future laser system with a frequency of 10 Hz and 10,000-s radiation in a hospital.

Assessment of the usability conditions of Sb2O3–PbO–B2O3 glasses for shielding purposes in some medical radioisotope and a wide gamma-ray energy spectrum

Abstract We report some fundamental gamma-ray shielding properties and individual transmission factors (TFs) of five distinct glass samples with a nominal composition of xSb2O3·(40 − x)PbO·60B2O3·0.5CuO and (where; 0 ≤ x ≤ 40 mol%). Phy-X/PSD and MCNPX (version 2.7.0) Monte Carlo code are utilized to determine several critical parameters, such as cross-sections, attenuation coefficients, half and tenth value layers, build-up factors, and TFs. A general transmission setup is designed using basic requirements. Accordingly, TFs are evaluated for several medical radioisotopes. Next, the gamma-ray shielding parameters and TFs are assessed together in terms of providing the validity of the findings. Our results showed that there is a positive contribution of increasing Sb2O3 amount in the glass matrix owing its direct effect to the density increment as well. This positive effect on gamma-ray shielding properties is also observed for decreasing mean free path values from S1 to S5 samples. The exposure build-up factor (EBF) and energy absorption build-up factor (EABF) values, increasing the quantity of Sb2O3 supplementation, resulted in a general reduction in EBF and EABF values (i.e., from 0.5 to 40 mfp). When the quantity of Sb2O3 rises from S1 to S5, the collision rate of incoming gamma rays in glass samples increases significantly. The TF figures reveal that S5 showed the least transmission behavior across all the above-mentioned studied glass thicknesses. It can be concluded that increasing the Sb2O3 additive is a beneficial and monotonic technique, when the gamma-ray shielding qualities or TF values must be further enhanced.

Determination of gamma-ray transmission factors of WO3–TeO2–B2O3 glasses using MCNPX Monte Carlo code for shielding and protection purposes

Abstract The aim of this study is to assess the individual gamma-ray transmission factors (TFs) and some fundamental gamma-ray attenuation properties of several types of glasses based on WO3–TeO2–B2O3 glasses system. MCNPX (version 2.7.0) is used for the calculation of TFs. Other critical parameters are determined using the Phy-X/PSD program. To determine the TFs of studied glasses, several medical radioisotopes are determined along with their characteristic gamma-ray energies. The superior values for the investigated parameters are found in glass sample S6. Furthermore, the exposure build-up factor and energy absorption build-up factor values for glass sample S6 were the lowest. S6 glass sample with the chemical composition 0.03833B + 0.26075O + 0.11591Zn + 0.52783Te + 0.05718W and a density of 3.3579 g/cm3 is found to have exceptional gamma-ray attenuation qualities, according to our findings. It can be concluded that the prospective attributes of WO3-doped glass systems and associated glass compositions would be beneficial for scientific community in terms of providing a clearer view for some advanced applications of these glass types.

Highly Enriched Uranium-Free Medical Radioisotope Production Methods: An Integrative Review

The ever-growing need for radiopharmaceuticals, i.e., compounds containing pharmaceutical drugs and radioisotopes used for medical diagnostic imaging (SPECT/PET scan) and treating neoplasms, is significantly leading to an increased demand for such substances in hospitals and clinics worldwide. Currently, most large-scale productions of radioisotopes required for radiopharmaceuticals are carried out in research reactors, via the fission of highly enriched uranium. However, because large amounts of radioactive waste are produced as byproducts in this process, new greener methods are needed for radioisotope production. This work presents an integrative literature review and summarizes enriched uranium-free methods for radioisotope production, accomplished through the adoption of new reaction routes, distinct acceleration technologies, or by using other physical processes. This review considered forty-eight studies published from 2010 to 2021 on three established virtual databases. Among these selected works, a cyclotron is the most adopted HEU-free method for radioisotope production, and 44Sc, 68Ga, and 99mTc are the medical radioisotopes most often reported as produced by using the investigated HEU-free production methods.

Excitation functions of alpha particle induced nuclear reactions on natBa up to 60 MeV

The excitation functions of nuclear reactions natBa(α,xn)132, 133m, 134, 135, 137m,g, 139, 141Ce, natBa(α,x)135, 140La and natBa(α,x)131, 133m, 135mBa were measured for the first time in the energy range of 60 → 20 MeV using stack foil technique combined with γ-ray spectrometry. A comparative analysis of the experimental results with TENDL-2021 data was carried out. The thick target yields of radioisotopes Ba, La, and Ce were calculated by integrating the values of the cross sections. The feasibility of practical use of the studied reactions for the production of medical radioisotopes 134Ce and 135La is discussed.

Gadolinium-tungsten-boron trioxide glasses: A multi-phase research on cross-sections, attenuation coefficients, build-up factors and individual transmission factors using MCNPX

The oxide of the rare earth element gadolinium has the chemical formula Gd2O3. Also known as gadolinium sesquioxide, gadolinium trioxide, and Gadolinia, gadolinium oxide. In this study, various types of fundamental cross-sections, attenuation coefficients, build-up factors and individual transmission factors of high density gadolinium-tungsten-boron trioxide glasses with a chemical composition of (70-x)WO3-xGd2O3 –30B2O3 (where x: 17.5, 20.0, 22.5, 25.0 and 27.5 mol%) are determined using advanced Monte Carlo methods. In addition, gamma transmission factors (TFs) for a range of medical and industrial radioisotopes were calculated using MCNPX (version 2.7.0) Monte Carlo code. The investigated glasses were classified Gd17.5, Gd20.0, Gd22.5, Gd25.0, and Gd27.5 in accordance with xGd2O3. Our findings suggest that the Gd27.5 sample (with highest of Gd2O3 content mol. %) has possessed the maximum linear (µ) and mass (µ/ρ) attenuation coefficients at all gamma-ray energies investigated. The coded glass sample Gd27.5 is achieved the maximum effective atomic number (Zeff) and effective electron density (Neff) owing its superior attenuation properties. In terms of build-up factors, increasing the concentration of xGd2O3 in glasses is decreased the EBF and EABF values for all mean free path values (0.5–40 mfp). At a thickness of 3 cm, the lowest transmission factor (i.e., highest attenuation) was verified for all Gd17.5-Gd27.5 glasses investigated. Consequently, the Gd27.5 sample exhibits superior radiation shielding properties for a large range of photon energy and various medical and industrial radioisotope energies.

PHOTONUCLEAR PRODUCTION OF 99Mo/ 99mТс-GENERATOR WITH USING EFFECT SZILARD-CHALMERS AND ELECTROLYSIS METHOD

The possibility of photonuclear production of 99Mo medical radioisotope using recoil nuclei of molybdenite nanoparticles from reaction 100Mo(γ,n)99Mo was investigated. The enrichment of radioactive isotopes is carried out by the effect of Szilard-Chalmers. Molybdenite nanoparticles were irradiated by bremsstrahlung with Emax = 39 MeV. The recoil nuclei of 99Mo are separated by electrolysis. The yield of 99Mo from the extractable phase amounted to ~3%. This technology will allow producing 0.8 GBq/g of 99mTc with high specific activity per day. Key words: linear electron accelerator, photonuclear production, electrolysis, specific activity, recoil nuclei, molybdenite nanoparticles.

Optical fibre array detector to monitor irradiations for medical radioisotope production

Low-energy cyclotrons are in use worldwide to produce medical radioisotopes for nuclear medicine. Beam monitoring during the irradiation of targets is difficult due to the high-power density of low-energy protons, space limitations, and interference with beam delivery. Doped silica fibres are sensitive to prompt ionizing radiation from the bombarded target, and produce radiation induced luminescence (RIL) when exposed. The fibres can be attached to the outside of the target in a low-profile fibre array, ensuring efficient and safe operation. Here, we present the results from our prototype of such a fibre array. It consists of four Ce-doped fibres with a diameter of 200 μm and has been installed at the TR13 medical cyclotron at TRIUMF where it has been tested at different irradiation conditions.

PROGRESS IN NICKEL TARGET DESIGNS FOR DEUTERON IRRADIATION: A MILESTONE IN RADIOISOTOPE PRODUCTION OPTIMIZATION

Medical radioisotopes play significant roles in nuclear medicine, particularly in tumor diagnosis and its therapy. Optimization in production of these important isotopes is very essential for the overall health of the target patients. In this work, we analyzed general trends in the use of various forms of nickel metal as target for radioisotopes production in nuclear accelerators. A careful study of all previously used forms of nickel metal in the literature up to 2016 indicate that different physical forms of the metal, such as its very high purity and impure forms, alloys, compounds and powdered forms have, over the years, been used for various radioisotope productions under deuteron irradiation route, each providing different production effect. The excitation functions of several useful radioisotopes could be studied under deuteron irradiation of nickel. In a recent experimental work by the authors, some very pure, thin nickel foils of natural isotopic composition were also used in form of stacked arrangement for deuteron irradiation. The study found that most of the recent studies on radioisotopes production cross sections use very high purity and solid nickel forms.