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Rhenium-186 [t½ = 3.7 d, 1.07 MeV β−-particles, 137 keV γ-ray] is an emerging radioisotope which holds tremendous potential in preparation of theranostic radiopharmaceuticals. This radioisotope was produced in a no-carrier-added form by irradiation of enriched 186W target via 186W(p, n) 186Re reaction in a pelletron. A facile radiochemical separation procedure based on selective solvent extraction in methylethyl ketone medium followed by column chromatography using mesoporous alumina sorbent has been developed to obtain 186Re in a form suitable for radiopharmaceutical preparation. This approach is expected to promote widespread utilization of this radioisotope for the benefit of cancer patients. [ABSTRACT FROM AUTHOR]

Effect of fast neutron irradiation induced defects on the anti-ferromagnetic (AFM) to ferromagnetic (FM) transition in Ce(Fe0.96Ru0.04)2 is studied by magnetic measurements. We observe that at a given temperature, AFM-FM transition occurs at a lower field in irradiated specimens compared to that in pristine samples. While irradiation does not seem to affect the hysteresis of the transition, zero field susceptibility is enhanced by more than an order of magnitude. Analysis of reversible magnetization vs field data at low fields indicates superparamagnetic behavior of nano-sized FM domains, which are conjectured to nucleate on the crystal defects produced by the fast neutron irradiation. The number density and size of the nano-sized domains in the irradiated and pristine samples are estimated from the magnetization data. [ABSTRACT FROM AUTHOR]

In this article, we describe a simple and facile approach for the production of 125I from the neutron-irradiated natural Xe using wet chemical distillation. First, we outline the design of the irradiation container, its fabrication, cryogenic loading of the gaseous Xe target into the irradiation container, and hermetic sealing of the irradiation container. Quality-assurance tests of the irradiation containers were performed to ensure their safety during neutron irradiation. In light of the implicit need to obtain 125I activity with minimum126I radionuclidic contamination, the irradiation time, neutron flux, and target cooling time were judiciously optimized. A thorough optimization of experimental parameters of distillation was carried out to obtain the optimal yield of 125I having the desired purity. In each batch, typically 4 g of natural xenon gas was irradiated in the BARC Dhruva reactor for 15 days with a thermal neutron flux of approximately 5 × 1013 cm–2 s–1. After irradiation, the targets were left to decay for typically ∼50 days to reduce the 126I contamination. Several batches of 125I were successfully produced using the developed procedure at a level of ∼18.5 GBq (500 mCi) 125I per batch. The 125I quality in terms of radionuclidic purity, radiochemical purity, and radioactive concentration was evaluated and found to be acceptable for radiolabeling studies. This reported method currently has been adapted for the routine production of 125I to meet local needs. [ABSTRACT FROM AUTHOR]

Radiotracers are extensively used in many industries for trouble shooting and optimization of process parameters leading to considerable savings in time and huge economic benefits. In chemical and petrochemical industries different gases and vapours flowing in the conversion reactors play a major role in the final production. Gaseous radiotracers are ideal to study hydrodynamics of gas phases in process vessels. 41Ar and 79Kr are the preferred gaseous radiotracers for such studies. Owing to the increase in demand from Indian industries for gas phase radiotracers, efforts have been made to produce 41Ar and 79Kr indigenously by irradiation of 40Ar and enriched 78Kr gaseous targets in research reactors. Prequalification of the containers used, safety aspects concerning accidental rupture and mandatory tests necessary for irradiation of gaseous targets in the reactors have been studied. The paper describes some of the important safety aspects involved and the results of trial irradiations on the production of 41Ar and 79Kr radiotracers. Standardization of suitable assay protocols for their regular production and supply for applications in industries is also described. [ABSTRACT FROM AUTHOR]

Technetium-99 is a radioactive waste produced primarily in nuclear reactors. It is also left as radioactive waste in hospitals, directly from 99m Tc isomeric state. To bring down the quantity of technetium-99 radioactive waste, the nuclear reactions using photon beam is explored. The integral cross section of the reaction 99 Tc(γ,γ') 99m Tc has been determined using the photo-nuclear activation method. The experiment was done using bremsstrahlung photons having endpoint energies viz. 6, 9, 12, 16, and 20 MeV. 115 In(γ,γ') 115m In reaction has been used as a monitor reaction, for the flux normalization of the bremsstrahlung spectrum. Theoretical model calculations have been done using the nuclear reaction code Talys 1.9. Theoretical parameter values are optimized with the presently obtained data. Total cross sections are estimated and investigated the feasibility of re-utilization of the technetium-99 radioactive isotope., Competing Interests: Declaration of competing interest I hereby declare that this article does not contain any conflict of interests by any other authors., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Copper-64 is an excellent theranostic radiometal that is gaining renewed attention of the clinical community in the recent times. In order to meet the increasing demand of this radiometal, we have demonstrated the viability of its production via 64 Zn (n,p) 64 Cu reaction in a nuclear reactor. A semi-automated radiochemical separation module based on selective extraction of 64 Cu as dithizonate complex was developed. The maximum available activity at the end of irradiation was ~ 700 MBq. The overall yield of 64 Cu after the separation process was >85% and it could be obtained with ~12 GBq/μg specific activity, >99.9% radionuclidic purity and >98% radiochemical purity. The separated 64 Cu could be utilized for preparation of a wide variety of radiopharmaceuticals., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Routine availability of high specific activity 186 Re would provide a significant boost to the development of potent theranostic radiopharmaceuticals. In the present study, 181- 186 Re was produced by proton bombardment (12 MeV, average beam intensity 180 nΑ) for 60 h on natural tungsten oxide target. A facile electrochemical method has been developed for radiochemical separation of Re radioisotopes from irradiated target material. The overall yield of the process was >80% and Re radioisotopes could be separated in a form suitable for preparation of radiopharmaceuticals., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This paper describes prerequisite tests, analysis and the procedure for irradiation of gaseous targets and production of gaseous radioisotopes i.e. argon-41 ((41)Ar) and krypton-79 ((79)Kr) in a 100MWTh DHRUVA reactor located at Bhabha Atomic Research Center (BARC), Trombay, Mumbai, India. The produced radioisotopes will be used as radiotracers for tracing gas phase in industrial process systems. Various details and prequalification tests required for irradiation of gaseous targets are discussed. The procedure for regular production of (41)Ar and (79)Kr, and assay of their activity were standardized. Theoretically estimated and experimentally produced amounts of activities of the two radioisotopes, irradiated at identical conditions, were compared and found to be in good agreement. Based on the various tests, radiological safety analysis and standardization of the irradiation procedure, necessary approval was obtained from the competent reactor operating and safety authorities for regular production of gaseous radiotracers in DHRUVA reactor., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

This paper describes development of (169)Yb-seeds by encapsulating 0.6-0.65 mm (ϕ) sized (169)Yb2O3 microspheres in titanium capsules. Microspheres synthesized by a sol-gel route were characterized by XRD, SEM/EDS and ICP-AES. Optimization of neutron irradiation was accomplished and (169)Yb-seeds up to 74 MBq of (169)Yb could be produced from natural Yb2O3 microspheres, which have the potential for use in prostate brachytherapy. A protocol to prepare (169)Yb-brachytherapy sources (2.96-3.7 TBq of (169)Yb) with the use of enriched targets was also formulated., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Large-scale production of ³²P for its clinical use in palliative care of painful bone metastasis in the form of Na3[³²P]PO₄ (³²P-sodium orthophosphate) has been practiced for six decades. The classical route of production of ³²P by (n,p) reaction on high purity elemental sulfur yields no-carrier-added (NCA) ³²P. Since high specific activity ³²P is not essential for the formulation of Na₃[³²P]PO₄ for bone pain palliation, an alternate route of production of ³²P by direct neutron capture using elemental phosphorus target [(31)P(n,γ)³²P] was envisaged and its suitability for use in bone pain palliation was evaluated. Toward this, irradiation of elemental red phosphorus target was carried out at a neutron flux of 8×10¹³ n/cm².s for 60 days and this yielded ³²P with a specific activity of 230±15 MBq/mg (6.2±0.4 mCi/mg) having >99.9% radionuclidic purity. About 370-555 MBq (10-15 mCi) doses of Na₃[³²P]PO₄ were formulated in sterile saline (pH 7.4) using the ³²P produced. The radiochemical purity of the formulation was found to be ~99% with respect to PO₄³⁻. The formulation exhibited good in vitro stability in saline and in human serum. Biodistribution studies carried out in normal Wistar rats revealed comparable pharmacokinetic properties of the formulation prepared using (n,γ) produced ³²P with that of NCA ³²P produced by (n,p) route. Besides having the advantages of simplicity in radiochemical processing and minimum radioactive waste generation, use of the proposed production route in place of the traditional ³²S(n,p)³²P route would result in better utilization of irradiation volume of research reactors.