Enrichment System, Method for Producing 177LU Using an Enrichment System, System for Converting 176YB to 177LU, Method for Preparing 177LU Product Material from 176YB Source Material, Cyclic Method for Generating and Separating 177LU, Cyclic Enrichment Method and Enrichment System

Description

Title: ENRICHMENT SYSTEM, 177LU PRODUCTION METHOD USING ENRICHMENT SYSTEM, SYSTEM FOR CONVERTING 176YB INTO 177LU, METHOD FOR PREPARING 177LU PRODUCT MATERIAL FROM 176YB SOURCE MATERIAL, CYCLIC METHOD OF GENERATING AND SEPARATING 177LU, CYCLIC ENRICHMENT METHOD AND ENRICHMENT SYSTEM (51) Int. Cl.: G21G 1 / 06; G21G 1 / 00; B01D 7 / 00. (30) Unionist Priority: 04 / 04 / 2023 US 18 / 130,461; 27 / 12 / 2023 US 18 / 397,202. (71) Depositor(s): CVF INTERNATIONAL LLC. (72) Inventor(s): PAVEL MOSEEV; ALEKSANDR KLACHKOV; ROMAN TERTYCHNYY; ALEKSANDR KHASIN. (86) PCT Application: PCT IB2024053194 of 02 / 04 / 2024 (87) PCT Publication: WO 2024 / 209343 of 10 / 10 / 2024 (85) National Phase Date: 26 / 09 / 2025 (57) Abstract: Methods and systems are provided for cyclic enrichment, especially of rare earth elements and isotopes. A tube, or ampoule, optionally with a crucible, or with two coaxially opposed crucibles in fluid communication, is used to hold a source material in vacuum and irradiate the source material to enrich it with the product material. After irradiation of the parent substance (e.g., Yb, enriched with 176Yb) to produce the product substance (e.g., 177Lu), the mixture can be sublimated to remove most of the parent substance and concentrate the product material, for example, by heating the bottom and cooling the top of the tube to condense the sublimated parent material at the top of the tube.Subsequently, the concentrated product substance can be purified, while the solidified source structure can be reused in irradiation / sublimation cycles to further enrich and concentrate the product material. Fig. 1A 1 / 33 Enrichment System, Production Method of 177LU Using the Enrichment System, System for Converting 176YB into 177LU, Method for Preparing 177LU Product Material FROM SOURCE MATERIAL176YB, CYCLIC METHOD OF GENERATION AND SEPARATION OF177LU, CYCLIC ENRICHMENT METHOD AND ENRICHMENT SYSTEM FIELD OF THE INVENTION

[0001] The present invention relates to the field of physical-chemical methods for separating substances, and more particularly, to systems and methods for separating lutetium (Lu) and ytterbium (Yb). BACKGROUND OF THE INVENTION

[0002] The following patents and patent applications are incorporated herein by reference in their entirety: 1. Gschneidner 1965 (The application of vacuum metallurgy in the purification of rare metals, OSTI technical report, Ames Lab., Iowa State Univ. of Science and Tech., From Vacuum Metallurgy Conference, New York.) teaches vacuum distillation and melting separation processes for rare earth metals and provides various reduction and purification techniques. 2. Russian Patent No. 2704005 describes a method for the carrier-free production of the radionuclide lutetium-177 by irradiating metallic ytterbium as the target substance in a thermal neutron stream in the reactor. The separation of the target substance is carried out by its evaporation in the ballast volume under high vacuum at a temperature of 700-800°C, resulting in the radionuclide lutetium-177 as the reaction product (Yb-176(n,y)>Yb-177>Lu-177) on the inner surface of the vessel, washing it with a hydrochloric or nitric acid solution. Petition 870250087577, dated 09 / 26 / 2025, page 10 / 82 2 / 33 3. WIPO Publication No. 2019106182 teaches compounds of the following formula for chromatographic separation of rare earth elements and / or s-, P-, d- metals: 4. WIPO publications WO2021102167 and WO2021202914 teach methods for purifying lutetium by providing a solid composition comprising ytterbium and lutetium and sublimating or distilling ytterbium from the solid composition at a temperature of about 1196°C to about 3000°C to leave a lutetium composition comprising a higher percentage by weight of lutetium than that present in the solid composition. 5. US Publication No. 20240011125 teaches the sublimation or distillation of a ytterbium composition from an initial solid composition comprising ytterbium and lutetium in an inert or reduced pressure environment and at a first average temperature for a first sublimation / distillation period to leave a lutetium composition comprising a higher weight percentage of lutetium than was present in the initial solid composition, collecting the ytterbium composition; retaining the ytterbium composition for a holding period to form a decayed ytterbium composition, wherein the holding period is longer than the first sublimation / distillation period; and subsequently to the holding period, sublimating or distilling a refined ytterbium composition from the decayed ytterbium composition in an inert or reduced pressure environment and at a second average temperature for a second sublimation / distillation period to leave a residual composition. Petition 870250087577, dated 09 / 26 / 2025, p. 11 / 82 3 / 33 6. U.S. Publication No. 20240068071 describes a sublimation / distillation apparatus including a crucible with one open end, a heating device thermally coupled to the crucible, an actively cooled collection substrate disposed above the open end of the crucible, and a vacuum chamber housing the crucible, the heating device, and the actively cooled collection substrate. 7. U.S. Publication No. 20240035118 describes a phase change crucible comprising an inner chamber comprising an inner chamber wall extending from the floor of the inner chamber to the upper end of the inner chamber, an outer chamber comprising an outer chamber wall extending from the floor of the outer chamber to the upper end of the outer chamber, wherein the upper end of the inner chamber terminates beyond the upper end of the outer chamber and the outer chamber wall encircles the inner chamber wall, an inner collection region formed by the inner chamber wall and the inner chamber floor, and an outer collection region formed by the outer chamber wall, the inner chamber wall, and the outer chamber floor.

[0003] As discussed below, the disclosed modalities are advantageous compared to the state of the art in several aspects, such as yield, safety, 177Lu collection efficiency and / or product purity and / or concentration. The radioisotope 177Lu is useful, for example, in medical applications, such as image labeling or tumor treatment. BRIEF DESCRIPTION OF THE INVENTION

[0004] The following is a brief description that provides an initial understanding of the invention. The brief description does not necessarily identify the key elements nor limit the scope of the invention, but serves only as an introduction to the description that follows. Petition 870250087577, dated 09 / 26 / 2025, page 12 / 82 4 / 33

[0005] One aspect of the present invention provides an enrichment system comprising: a sealing unit configured to heat and generate a vacuum in a tube and consecutively seal the tube, wherein the tube is neutron permeable, heat resistant to at least 600°C and includes a source material, an irradiation unit configured to irradiate the source material in the sealed tube with neutrons to enrich the source material with a product material contained therein, a sublimation unit configured to sublimate the source material in the sealed tube to concentrate the product material within the sealed tube, and a handling unit configured to break the tube seal, separate the concentrated product material from the sublimated source material, and use the sublimated source material as source material for a consecutive enrichment cycle through the system.

[0006] One aspect of the present invention provides a method for producing 177Lu using the enrichment system, the method comprising: irradiating the 176Yb source material in the sealed tube with neutrons to enrich the source material with the 177Lu product material, sublimating 176Yb from the irradiated source material to concentrate the 177Lu product material within the sealed tube, and repeating the irradiation with the sublimated 176Yb as source material and the sublimation of 176Yb from the irradiated source material – to further concentrate the 177Lu product material.

[0007] One aspect of the present invention provides a cyclic method for generating and separating 177Lu comprising: placing a first crucible with 176Yb coaxially opposed and in fluid communication with a second crucible, with both crucibles placed inside a tube and both crucibles and the tube being transparent (permeable) to neutrons, heating and generating a vacuum in the tube and, subsequently, sealing the tube, irradiating the 176Yb in the first crucible in the sealed tube with neutrons to generate 176Yb enriched with 177Lu therein, sublimating 176Yb from the first crucible to the second crucible to concentrate the 177Lu in the first crucible, inside the sealed tube, breaking the tube seal, separating the first Petition 870250087577, dated 09 / 26 / 2025, p. 13 / 82 5 / 33 crucible with concentrated 177Lu from the second crucible with sublimated 176Yb, repeat the aforementioned configuration, heat, irradiate, sublimate and break through a plurality of cycles, use the second crucible with the sublimated 176Yb from each cycle to prepare the first crucible with 176Yb for the next cycle, and post-process the concentrated 177Lu from the plurality of cycles to produce purified 177Lu.

[0008] One aspect of the present invention provides a cyclic enrichment method comprising: placing a first crucible containing a coaxially opposed source material in fluid communication with a second crucible, with both crucibles placed inside a tube and both crucibles and the tube being transparent (permeable) to neutrons; heating and generating a vacuum in the tube; and subsequently sealing the tube; irradiating the source material in the first crucible of the sealed tube with neutrons to enrich the source material with a product material contained therein; sublimating the source material from the first crucible to the second crucible to concentrate the product material in the first crucible, inside the sealed tube; breaking the tube seal; separating the first crucible with the concentrated product material from the second crucible with the sublimated source material; repeating said configuration, heating, irradiating, sublimating, and breaking a plurality of cycles.Use the second crucible containing the sublimated source material from each cycle to prepare the first crucible containing the source material for the next cycle, and post-process the concentrated product material from multiple cycles to produce purified product material.

[0009] One aspect of the present invention provides an enrichment system comprising: a sealing unit configured to heat and generate a vacuum in a tube and subsequently seal the tube, wherein the tube includes a first crucible with a coaxially opposed source material in fluid communication with a second crucible, with both crucibles placed inside the tube and both crucibles and the tube being transparent (permeable) to neutrons, an irradiation unit configured to irradiate the source material in the first crucible. Petition 870250087577, dated 09 / 26 / 2025, p. 14 / 82 6 / 33 crucible in a neutron-sealed tube to enrich the source material with a product material contained therein, a sublimation unit configured to sublimate the source material from the first crucible to the second crucible to concentrate the product material in the first crucible, inside the sealed tube, a handling unit configured to break the tube seal, separate the first crucible with the concentrated product material from the second crucible with the sublimated source material and use the second crucible with the sublimated source material as the first crucible with the source material for a consecutive enrichment cycle through the system, and a post-processing unit configured to produce purified product material from the concentrated product material from a plurality of enrichment cycles.

[0010] One aspect of the present invention provides a system for converting 176Yb into 177Lu, the system comprising: a vacuum-sealed tube; a first crucible comprising a first open end and having a 176Yb source material contained therein positioned within the sealed tube; a second crucible comprising a second open end positioned within the sealed tube, the second crucible coaxially aligned and in fluid communication with the first crucible and positioned with the second open end opposite the first open end of the first crucible; and an irradiation unit configured to irradiate the 176Yb source material in the sealed tube with neutrons to produce a 177Lu product material, wherein the tube and both crucibles are made of neutron-transparent (permeable) material.

[0011] One aspect of the present invention provides a method for preparing product177Lu material from source176Yb material, the method comprising irradiating the source176Yb material with neutrons in a vacuum-sealed tube to sublimate the source176Yb material and produce product177Lu material, wherein the sealed tube comprises a first crucible comprising a first open end having the source176Yb material contained therein and a second crucible comprising a second open end positioned within the Petition 870250087577, dated 09 / 26 / 2025, page 15 / 82 7 / 33 sealed tube, wherein the first and second crucibles are coaxially aligned and in fluid communication within the sealed tube, with the second open end of the second crucible opposite the first open end of the first crucible, and wherein the tube and both crucibles are made of neutron-permeable material.

[0012] These additional and / or other aspects and / or advantages of the present invention are presented in the detailed description below, possibly inferred from the detailed description and / or learnable by practicing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] For a better understanding of the embodiments of the invention and to demonstrate how it can be implemented, reference will be made, by way of example only, to the attached drawings, in which identical numerals designate corresponding elements or sections. In the attached drawings:

[0014] Figures 1A and 1B are high-level schematic block diagrams of enrichment systems in operation, according to some embodiments of the invention.

[0015] Figures 2A-2C are high-level flowcharts illustrating cyclic enrichment methods according to some embodiments of the invention.

[0016] Figure 3 is a high-level, non-limiting schematic example of the operation of enrichment systems for cyclic generation and separation of 177Lu, according to some embodiments of the invention.

[0017] Figure 4 is a high-level schematic illustration of a possible configuration and operating principle of the sealing unit during the tube sealing process, according to some embodiments of the invention.

[0018] Figure 5A is a high-level schematic illustration of a possible embodiment of the sublimation unit during the ytterbium sublimation process. Petition 870250087577, dated 09 / 26 / 2025, p. 16 / 82 8 / 33 as an example for the source material, according to some embodiments of the invention.

[0019] Figure 5B provides high-level schematic illustrations of the sealed tube and the sublimation process contained therein, according to some embodiments of the invention.

[0020] Figure 6 is a high-level schematic illustration of a possible configuration and operating principle of the handling unit during the sealed tube rupture process, according to some embodiments of the invention.

[0021] Figures 7A-7C provide basic information, including the decay scheme of the radionuclide 177Lu illustrated schematically in Figure 7A, the dependence of the yield of 177Lu on the irradiation time of 176Yb for different values ​​of neutron flux density illustrated schematically in Figure 7B, and the specific activity of 177Lu as a function of irradiation duration and post-reactor storage / processing at different % contents of 174Yb in the initial isotope mixture illustrated schematically in Figure 7C.

[0022] It should be noted that, for simplicity and clarity of illustration, the elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some elements may be exaggerated in relation to other elements for greater clarity. In addition, when deemed appropriate, reference numbers may be repeated between figures to indicate corresponding or analogous elements. DETAILED DESCRIPTION OF THE INVENTION

[0023] The following description describes various aspects of the present invention. For explanatory purposes, specific configurations and details are presented in order to provide a complete understanding of the present invention. However, it will also be evident to a person skilled in the art that the present invention may Petition 870250087577, dated 09 / 26 / 2025, page 17 / 82 9 / 33 cannot be put into practice without the specific details presented here. Furthermore, well-known features may have been omitted or simplified so as not to obscure the present invention. With specific reference to the drawings, it is emphasized that the details presented are only by way of example and for the purpose of illustrative discussion of the present invention, and are presented with the aim of providing what is believed to be the most useful and easily understandable description of the principles and conceptual aspects of the invention. In this sense, there is no attempt to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, and the description made with the drawings makes evident to those skilled in the art how the various forms of the invention can be implemented in practice.

[0024] Before at least one embodiment of the invention is explained in detail, it should be understood that the invention is not limited in its application to the construction details and component arrangement presented in the following description or illustrated in the drawings. The invention is applicable to other embodiments that can be practiced or performed in various ways, as well as to combinations of the disclosed embodiments. Furthermore, it should be understood that the phraseology and terminology used herein are for descriptive purposes only and should not be considered limiting.

[0025] Some embodiments of the present invention provide efficient and economical methods and mechanisms for generating and separating materials, thus providing improvements in the technological field of materials separation and, especially, in the generation of radionuclides. Methods and systems are provided for cyclic enrichment, especially of rare earth elements and isotopes. A tube, or ampoule, optionally with a crucible, or with two coaxially opposed crucibles in fluid communication, is used to maintain a source material under vacuum and irradiate the source material to enrich it with the product material. After irradiation of the source substance (e.g., metallic Yb, enriched with 176Yb) to produce the product substance (by Petition 870250087577, dated 09 / 26 / 2025, page 18 / 82 10 / 33 example, 177Lu), the mixture can be sublimated to remove most of the parent substance and concentrate the product material, for example, by heating the bottom and removing the heat (cooling) from the top of the tube, to condense the sublimated parent material at the top of the tube. Subsequently, the concentrated product substance can be purified, while the solidified parent structure can be reused in irradiation / sublimation cycles to further enrich and concentrate the product material.

[0026] Figures 1A and 1B are high-level schematic block diagrams of an enrichment system 100 in operation, according to some embodiments of the invention. Figures 2A to 2C are high-level flowcharts illustrating cyclic enrichment methods 200, according to some embodiments of the invention. The steps of the method can be performed with respect to the enrichment system 100 described above, which can optionally be configured to implement the cyclic enrichment method 200. In some embodiments, the cyclic enrichment method 200 may comprise the cyclic generation and separation of 177Lu from 176Yb, and Figure 3 is a non-limiting high-level schematic example of the operation of the enrichment system 100 for cyclic generation and separation of 177Lu, according to some embodiments of the invention.However, the enrichment systems 100 and cyclic enrichment methods 200 disclosed may be applied to separate other elements and / or isotopes, as disclosed herein. The elements of Figures 1A-7C may be combined in any operable combination, and the illustration of certain elements in certain figures and not in others serves only an explanatory purpose and is not limiting.

[0027] The enrichment system 100 may comprise a sealing unit 150 configured to heat and generate vacuum in a tube 110 (e.g., a quartz ampoule in Figure 3) and consecutively seal the tube 110, which includes a first crucible 120A with a coaxially opposed source material and in Petition 870250087577, dated 09 / 26 / 2025, page 19 / 82 11 / 33 Fluid communication (face-to-face, with openings that allow the flow of material between the crucibles) with a second crucible 120B, with both crucibles 120A and 120B disposed within tube 110 and both crucibles 120A and 120B and tube 110 being neutron permeable, as schematically illustrated in the illustration inserted in Figure 1A. Crucibles 120A and 120B may be tightly fixed to each other (but are illustrated in Figure 1A as slightly separated, for clarity purposes only) and are coaxially aligned, possibly by an alignment device 125 (illustrated quite schematically). In some embodiments, the alignment device 125 may comprise an inert metal sealing ring. In certain embodiments, tube 110 may not comprise crucibles 120A and 120B, but may have the source and product materials deposited and sublimated on the inner surfaces of tube 110, as schematically illustrated in Figure 1B.After sublimation, tube 110 can be separated into two parts: the first section 110A with the remaining concentrated o177Lu, which can then be post-processed, and the second section 110B with the sublimated o176Yb, which can then be reused. In some embodiments, tube 110 may comprise only one crucible 120A or 120B – for which the respective materials are deposited and / or collected, as schematically illustrated in Figure 5B.

[0028] Correspondingly, as illustrated in Figure 2A, the cyclic enrichment method 200 may comprise configuring a first crucible 120A with a coaxially opposed source material in fluid communication with a second crucible 120B, with both crucibles placed inside a tube and both crucibles and the tube being neutron permeable (stage 210) and, optionally, aligning the crucibles coaxially (stage 215). The cyclic enrichment method 200 may further comprise heating and vacuum generation in the tube, and subsequent sealing of the tube (stage 220). For example, the source material may comprise 176Yb (e.g., with a 174Yb fraction of less than 1%) and the cyclic enrichment method 200 may comprise the cyclic generation and separation of 177Lu, as disclosed herein. Petition 870250087577, dated 09 / 26 / 2025, page 20 / 82 12 / 33 Alternatively, as illustrated in Figure 2B, the cyclic enrichment method 200 may comprise depositing the source material at the bottom of the tube, optionally in a crucible (stage 212), heating and generating a vacuum in the tube and consecutively sealing the tube (stage 220) and cyclically generating and separating the product material.

[0029] In several embodiments, the source material may be deposited in a first section 110A (e.g., the lower part, optionally including crucible 120A) of the sealed tube 110, from where the concentrated product material is collected; and the sublimated source material is collected within a second section 110B (e.g., the upper part, optionally including crucible 120B) of the sealed tube 110. If two crucibles 120A and 120B are used, they are arranged coaxially, in fluid communication through their opposite open ends. The tube 110 and the crucibles 120A and 120B, when used, are made of material(s) chemically inert to the respective source material and sublimated material, such as crucibles made of niobium or its alloys, and tubes made of quartz, or aluminum or its alloys. The handling unit 180 can be configured to separate sections 110A and 110B from tube 110 and / or crucibles 120A and 120B, when used, by various means.For example, as illustrated in Figures 1A, 1B, 5B and 6, the handling unit 180 can be configured to cut the tube 110 into two parts, for example, by forming a circular groove in the sealed tube and rupturing the tube consecutively along the groove to separate the concentrated product material from the sublimated source material.

[0030] Note that the terms upper and lower are used here in a relative sense in relation to the opposing crucibles or other parts of the systems and tubes revealed – to simplify the explanation, but not in a limiting way. In practice, and as verified experimentally, tube 110 can be adjusted and handled in any orientation (e.g., vertical, horizontal, oblique, or any other position, including inverting the parts indicated here as upper and lower), and the sublimation process can be conducted with tube 110 sealed in Petition 870250087577, dated 09 / 26 / 2025, page 21 / 82 13 / 33 any orientation (e.g., vertical, horizontal, or positioned at some intermediate angle), with the sublimated material passing from one crucible to the opposite crucible, or from one end of the tube to the opposite end of the tube, regardless of its spatial orientation.

[0031] Crucibles 120A and 120B and / or tube 110 (for example, when no or only one crucible is used) may be made of refractory material for high-temperature processing. For example, crucibles 120A and 120B (or possibly tube 110) may be made of niobium and / or niobium alloys further comprising in total up to 50% by mass of at least one of the following: zirconium, tungsten, tantalum, titanium, nickel, their combinations and / or alloys. Crucibles 120A and 120B may have a height (or length) between 3 mm and 100 mm (for example, within any of the following: 3-100 mm, 3-30 mm, 3-100 mm), or between 10 mm and 50 mm (for example, any of the following: 10 mm, 20 mm, 25 mm, 30 mm, 40 mm, 50 mm or intermediate values), a diameter between 4 mm and 30 mm (for example, any of the following: 4 mm, 6 mm, 8 mm, 10 mm, 15 mm, 20 mm, 30 mm or intermediate values) and a thickness of up to 2 mm.The thickness of the side walls of crucibles 120A and 120B may be less than 0.2 mm or within any of the following: 0.2-0.5 mm, 0.5-1 mm, 1-2 mm, or intermediate ranges or values. Crucibles 120A and 120B may be made with a ratio between the inner crucible width and the crucible wall thickness ranging from 1:1 to 20:1, preferably 5:1, to provide heat transfer perpendicular to the target axis.

[0032] Alignment device 125 may be installed between crucibles 120A and 120B and may comprise one or more inner and / or outer rings, or any other parts configured to ensure strict coaxial orientation of crucibles 120A and 120B relative to each other during sealing, irradiation and sublimation processes. The gap between crucibles 120A and 120B may be minimal or non-existent. The fitting of crucibles 120A and 120B to the inner tube 110 may be configured to prevent damage due to thermal changes in crucibles 120A and Petition 870250087577, dated 09 / 26 / 2025, page 22 / 82 14 / 33 120B during the processes, for example, not being completely airtight, to avoid damage to tube 110, for example, due to thermal expansion of crucibles 120A and 120B or other mechanical or thermal stresses applied during the process.

[0033] Tube 110 may be made of quartz and configured to be coupled to a vacuum device 152 and then sealed after separation from the vacuum device 152, maintaining an internal vacuum. For example, tube 110 may be welded or otherwise sealed at one end and welded or glued to a quartz tube of the vacuum device 152 at its opposite end (schematically indicated as vacuum seal 151, which may, for example, comprise a flange joint 151A (see Figures 3 and 4, with or without an additional vacuum seal 151) containing a quartz tube designed to connect to the unwelded end of the quartz tube 110 using a fastening sealing device, using glue or implementing other means of connection.

[0034] For example, tube 110 can be heated, for example, between 300°C and 600°C to desorb gases from the surface of the components, and vacuum can be applied to achieve a residual pressure in the tube of up to 10-7 hPa. In certain embodiments, the sealed tube 110 can be heated by the sublimation unit 170 between 400°C and 1000°C in its lower part, which contains the source material, and between 20°C and 300°C in its upper part, which contains the sublimated material. The volume of the sealed tube 110 can be at most any of the following: 100 ml, 30 ml, 10 ml or 3 ml, or intermediate values. The pressure inside the sealed tube 110 can be less than 100 kPa (1 bar) or be within any of the following: 1 to 100 kPa, 10⁻² to 1 kPa, 10⁻⁴ to 10⁻² kPa, 10⁻⁶ to 10⁻⁴ kPa or 10⁻⁸ to 10⁻⁶ kPa, or sub-ranges or intermediate values. After vacuum generation in tube 110, tube 110 can be sealed and separated from the vacuum device 152; the seal 153 is illustrated in a rather schematic way.For example, tube 110 can be welded or glued, for example, under static vacuum (e.g., under pressure up to 10-7 hPa) and by hydrogen flame welding using a burner. Petition 870250087577, dated 09 / 26 / 2025, page 23 / 82 15 / 33 single flame without injector, or by other means, such as an acetylene torch or laser welding. During welding for sealing, tube 110 can be consistently heated to a temperature not lower than 1100°C (for example, when tube 110 is made of quartz, 1100°C being close to the melting point of quartz), for example, under constant rotation of the burner tip around tube 110. The burner can be positioned so that the flame preferably enters at a 90° angle to the wall of tube 110, producing, in non-limiting examples, a triangular seal 153, as schematically illustrated in Figure 3, for example, by moving the burner tip around tube 110 along a zigzag path (up and down on the tip of tube 110, schematically illustrated and indicated by the numeral 153A) to ensure consistent heating.After a constriction is formed in tube 110 (for example, triangular seal 153 illustrated in the quartz ampoule), the flame intensity can be increased by simultaneously stretching the lower part of tube 110. Flame power control can be performed in both manual and automatic modes. The vacuum resistance of tube 110 can be checked by immersing the sealed ampoule in a container of water and discarding it if traces of water are found inside. The ytterbium-filled tube 110 can also be placed in a container made of aluminum, steel, or zirconium alloys to ensure mechanical resistance.

[0035] The enrichment system 100 may further comprise an irradiation unit 160 configured to irradiate the source material (e.g., metallic Yb, enriched with 176Yb) in the first crucible 120A within the neutron-sealed tube 110 to enrich the source material with a product material (e.g., 177Lu). Correspondingly, as illustrated in Figure 2A, the cyclic enrichment method 200 may comprise irradiating the source material in the first crucible 120A within the neutron-sealed tube to enrich the source material with a product material contained therein (stage 230), for example, irradiating 176Yb in the first crucible 120A of the neutron-sealed tube to generate 176Yb enriched with 177Lu. Alternatively, as Petition 870250087577, dated 09 / 26 / 2025, page 24 / 82 16 / 33 illustrated in Figure 2B, the cyclic enrichment method 200 may comprise irradiating the source material at the bottom of the sealed tube (or in a corresponding crucible) with neutrons to enrich the source material with product material contained therein (stage 230A).

[0036] Figure 4 is a high-level schematic illustration of a possible configuration and operating principle of the sealing unit 150 during the sealing process of the tube 110, according to some embodiments of the invention. In Figure 4, the tube 300 represents a non-limiting embodiment of the tube 110, and the crucibles 301 represent a non-limiting embodiment of the crucibles 120A and 120B.

[0037] The tube 300 with crucibles 301 inside the tube 300 can be fixed in a vacuum hermetic tube compression connection 302 (as a non-limiting example of the vacuum connection and / or sealing embodiment 151). The connection 302 can be connected to a vacuum rotary passage 303, for example, with an electric actuator motor configured to rotate the connection 302 and the tube 300, for example, at a constant speed. The rotary passage 303 can be in place and positioned with a support 304 (which can be adjustable). Vacuum pump 305 (as a non-limiting example of an embodiment of vacuum device 152) may comprise a turbomolecular pump with a dry (oil-free) mechanical (pre-vacuum) pump, possibly via a connecting bellows tube 306. Vacuum pump 305 may be configured to create a vacuum of up to 10-7 hPa in tube 300.A gas torch 307 (e.g., an oxygen-hydrogen torch), for example, configured to generate a flame temperature of at least 1500°C (2700°F), may be supplied with working gas from a gas supply unit 308. In some embodiments, the gas torch 307 may be configured to generate a flame temperature of up to 2800°C (5100°F), or any intermediate value. In some embodiments, the gas torch 307 may be replaced by a high-power laser. A tube holder 309, for example, weighing up to ½ lb (approximately 230 g), may... Petition 870250087577, dated 09 / 26 / 2025, page 25 / 82 17 / 33 to be fixed to the bottom of the tube to apply mechanical traction to the tube. After pumping the tube 300, it can be heated with a gas torch 307 in a position 310 above the upper crucible while rotated by the rotary passage 303, for example, to form the seal 153. The tube material can be selected to become malleable under the heat of the gas torch 307 and collapse by atmospheric pressure into the hermetic seal 153 over the upper crucible, forming a sealed tube, indicated as a tube 400 in Figure 5A described below (see also tube 110 after sealing in Figures 1A and 1B).

[0038] Figure 5A is a high-level schematic illustration of a possible embodiment of the sublimation unit 170 during the ytterbium sublimation process as an example for the source material, according to some embodiments of the invention. The irradiated sealed tube 400 can be placed in a heat-resistant support 401 to allow heating of the lower part of the sealed tube 400 with an electric heater 402. In some embodiments, a heat absorber 403 can be placed on top of the sealed tube 400. In some embodiments, the heat absorber 403 can be made in the form of a metal tube radiator / support. In some embodiments, the circulation of cold gas 405 (e.g., at ambient temperature) from a fan 404 or nozzle can be introduced over the top of the sealed tube 400 and the heat absorber 403 (if present).

[0039] Figure 5B provides high-level schematic illustrations of the sealed tube 400 and the sublimation process contained therein, according to some embodiments of the invention. Figure 5B provides a non-limiting example of the sublimation process, also described, for example, in Figures 1A-3. In Figure 5B, the sealed tube 406, 411, 415 represents a non-limiting embodiment of the tube 110, the crucibles 412, 416, 418 represent a non-limiting embodiment of the crucibles 120A and 120B. The ytterbium source material 408, 413, 417 provides a non-limiting example for the source material and the product material 410, 414, 419 provides a non-limiting example for the product material, respectively. Petition 870250087577, dated 09 / 26 / 2025, page 26 / 82 18 / 33 Note that Figure 5B schematically describes embodiments in which the bottom and / or top of tube 110 are used for deposited and / or sublimated material (respectively), replacing the use of one or both crucibles in the respective position in the tube.

[0040] Line A schematically illustrates an embodiment of a compact vacuum-sealed tube 406 with the ytterbium metallic source material 408 deposited, pressed, or poured in liquid form and solidified inside the tube (left). After the sublimation process is conducted (right) in the sublimation unit 170, the ytterbium is deposited at the unheated (upper) end of the sealed tube 406. The concentrated product material 410 remains at the hot (lower) end of the sealed tube 406. Line B schematically illustrates an embodiment of a compact vacuum-sealed tube 411 with a crucible 412 containing the ytterbium source material 413 placed inside (left).After the sublimation process is conducted (right) in sublimation unit 170, ytterbium 413 is deposited at the unheated (upper) end of the sealed tube 411, while the concentrated product material 414 remains at the hot (lower) end of the sealed tube, inside crucible 412. Line C schematically illustrates an embodiment of using a compact vacuum-sealed tube 415 with an empty crucible 418 and a crucible 416 containing the ytterbium 417 source material placed inside (left). After the sublimation process is conducted (right) in sublimation unit 170, ytterbium 417 is deposited in crucible 418 at the unheated (upper) end of the sealed tube 415, while the concentrated product material 419 remains at the hot (lower) end of the sealed tube, inside crucible 416.

[0041] Figure 6 is a high-level schematic illustration of a possible configuration and operating principle of the handling unit 180 during the process of breaking the sealed tube 502, according to some embodiments of the invention. In Figure 6, the sealed tube 502 represents a non-limiting embodiment of the tube 110. Petition 870250087577, dated 09 / 26 / 2025, page 27 / 82 19 / 33

[0042] The handling unit 180 may comprise a tube holder 500, having, for example, a cylindrical cavity 501 to support the sealed tube 502 with a depth of, for example, about half the length of the sealed tube 502 in some embodiments. On top of the cylindrical cavity 501 and, for example, coaxial to it, a tube 503 with a hinge 504 may be placed. In some embodiments, the hinge 504 may be replaced by a piece of elastic tube. The sealed tube 502 may be placed in the cavity 501 and then the mechanical force of an electric, pneumatic or manual pusher 505 may be applied to the tube 503 until the sealed tube 502 is broken. In some embodiments, a circular groove 506 may be made in the sealed tube 502 with a glass cutting tool prior to its placement in the cavity 501, to act as an intended breaking point.

[0043] For the non-limiting examples of 177Lu generation from 176Yb irradiation disclosed herein, Figures 7A-7C provide basic information, including the decay scheme of the 177Lu radionuclide schematically illustrated in Figure 7A, the dependence of 177Lu yield on 176Yb irradiation time for different neutron flux density values ​​schematically illustrated in Figure 7B, and the specific activity of 177Lu as a function of irradiation duration and post-reactor storage / processing at different % 174Yb contents in the initial isotope mixture schematically illustrated in Figure 7C. Further discussion of these properties is provided below.

[0044] The irradiation unit 160 may comprise a nuclear reactor core, as, for neutron irradiation. The irradiation time may be determined in relation to the desired activity of 177Lu and the specific reactor parameters (neutron flux at the target).

[0045] In some embodiments, the irradiation unit 160 may comprise any nuclear fusion-based source, such as devices (e.g., reactors) Petition 870250087577, dated 09 / 26 / 2025, page 28 / 82 20 / 33 or generators) that conduct Deuterium-Tritium or Deuterium-Deuterium fusion reactions, generating neutrons in a vacuum tube or chamber.

[0046] In some embodiments, the irradiation unit 160 may comprise any type of particle accelerator-based neutron source, in which an accelerated beam of protons or deuterium is directed at a converter, or target body, containing beryllium, lithium, or other light nuclei, so that the neutron flux is generated by the impact of the beam.

[0047] In some embodiments, the irradiation unit 160 may further comprise a moderator medium in the path of the neutrons to the irradiated sealed tube to reduce the energy of the moderated (slowed down) neutrons to thermal energy (below 0.5 eV) or resonance energy (below 10 keV). In some embodiments, the moderator medium may comprise, for example, polyethylene, carbon, beryllium or heavy water.

[0048] The enrichment system 100 may further comprise a sublimation unit 170 configured to sublimate (transform from solid to gas and vice versa) the source material (e.g., metallic Yb, enriched with 176Yb) from the first crucible 120A to the second crucible 120B (in which it may condense, transforming from gas to solid) to concentrate the product material (e.g., 177Lu) in the first crucible 120A, inside the sealed tube 110. Correspondingly, as illustrated in Figure 2B, the cyclic enrichment method 200 may comprise sublimation of the source material from the first crucible 120A to the second crucible 120B to concentrate the product material in the first crucible 120A, within the sealed tube (stage 240), for example, sublimation of 176Yb from the first crucible 120A to the second crucible 120B to concentrate 177Lu in the first crucible 120A, within the sealed tube.Alternatively, as illustrated in Figure 2B, the cyclic enrichment method 200 may comprise sublimation of the source material from the bottom of the sealed tube (or a corresponding crucible) to the top of the tube. Petition 870250087577, dated 09 / 26 / 2025, p. 29 / 82 21 / 33 sealed (or a corresponding crucible contained therein) to concentrate the product material within the sealed tube (stage 240A).

[0049] For example, sublimation can be carried out by heating the first crucible 120A and condensing the sublimated Yb at the bottom of the second crucible 120B, opposite an opening of the same. The heating of the first crucible 120A can be carried out at temperatures between 400°C and 1000°C (for example, any of 400°C, 500°C, 600°C, 700°C, 800°C, 900°C, 1000°C or any intermediate values) and the temperature of the second crucible 120B can be maintained between 20°C and 300°C (for example, any of 20°C, 40°C, 50°C, 70°C, 100°C, 200°C, 300°C or any intermediate values), and sublimation can be carried out between 10 minutes and 10 hours (for example, any of 10, 30, 60 minutes, 2, 4, 6, 10 hours or any intermediate values). In several embodiments, heating can be carried out gradually and / or any of the revealed temperatures can be modified during the process to optimize the resulting yields and / or other process parameters.

[0050] The temperature difference between crucibles 120A and 120B can be obtained by heating the former and cooling the latter, and / or using a partition to obtain at least a partial thermal separation of the upper and lower parts of tube 110, for example, by controlling different heat transfers in a furnace and / or electromagnetic induction and / or radio frequency heating, by blowing air at one or more temperatures, by providing heat shields and / or reflectors, etc.

[0051] In several embodiments, the 176Yb sublimated in the second crucible 120B may include at least 97% by weight, 98% by weight, 99% by weight, 99.5% by weight, or any intermediate or higher values, and the 177Lu concentrated in the first crucible 120A includes at most 3% by weight, 2% by weight, 1% by weight, 0.5% by weight, or any intermediate or lower values ​​of the 176Yb originally defined in the first crucible 120A. Consequently, the ytterbium obtained in the sublimation process can be used to produce a new target without further processing, and the lutetium content in the total mass in the lower crucible can reach 50%. Petition 870250087577, dated 09 / 26 / 2025, page 30 / 82 22 / 33 (1:1 Yb / Lu ratio), as a non-limiting example, which greatly facilitates the extraction and chromatographic post-treatment process revealed here.

[0052] In several embodiments, sublimation can be used or applied to purify the source material from non-volatile impurities. In several embodiments, the enrichment system 100 can be configured to prepare the source material by heating and sublimation (possibly repeated). For example, the processes described can be performed one or more times without the irradiation and product extraction steps, to purify the source material one or more times before the formation (by irradiation) and extraction of the product material from the source material.For example, the sublimation unit 170 can be further configured to sublimate the source material in preparation for irradiation, for example, with the source material being deposited in the first section 110A and / or the first crucible 120A of the sealed tube 110, from which the source material is sublimated in the second section 110B and / or the second crucible 120B of the sealed tube 110 - to form purified source material, which is then used as the source material that is irradiated to enrich the target material and sublimated to concentrate the product material, while the non-volatile impurities remain in the first section 110A and / or the first crucible 120A of the sealed tube 110.Correspondingly, handling unit 180 can be configured to rupture tube 110 after purification of the source material by sublimation, to separate the purified source material from the ruptured tube (and optionally from the first crucible 120A), and to use the purified source material as source material for subsequent enrichment by irradiation and sublimation, as disclosed herein. Correspondingly, sealing unit 150 can be configured to seal tube 110 containing the purified source material for subsequent enrichment by irradiation and sublimation, as disclosed herein.

[0053] Non-limiting examples of non-volatile impurities that can be totally or partially removed from the source material include lanthanum La, gadolinium Gd, Petition 870250087577, dated 09 / 26 / 2025, page 31 / 82 23 / 33 lutetium Lu (including the decay product of 175Lu from 175Yb, which may be present due to the presence of 174Yb impurities during previous irradiations), hafnium Hf, erbium Er, thulium Tm (including the decay product of 169Tm from 169Yb, which may be present due to the presence of 168Yb impurities during previous irradiations), etc. As schematically illustrated in Figure 2C, the cyclic enrichment method 200 may comprise purifying the source material and / or product of non-volatile impurities (stage 205) by: depositing the source material at the bottom of the tube, optionally in a crucible (stage 212A), heating and generating a vacuum in the tube and subsequently sealing the tube (stage 220A), sublimating the material from the bottom of the sealed tube (or a corresponding crucible) to the top of the sealed tube (or a corresponding crucible within it) to concentrate the source material or product within the sealed tube (stage 240B), optionally breaking the tube seal,Separating the bottom of the sealed tube (or crucible within it) containing non-volatile impurities from the top of the sealed tube (or crucible within it) containing the sublimated material (stage 250B) and, optionally, repeating the stages of method 212A, 220A, 240B, 250B (deposit 212A, heat 220A, sublimate 240B and break 250B) for multiple cycles, using the sublimated material from the top of the tube from each cycle to supply the material at the bottom of the tube for the next cycle (stage 260B).

[0054] The enrichment system 100 may further comprise a handling unit 180 configured to break the tube seal 153, separate the first crucible 120A containing concentrated product material (e.g., 177Lu) from the second crucible 120B containing sublimated source material (e.g., metallic Yb, enriched with 176Yb), and use the second crucible 120B containing sublimated source material as the first crucible 120A containing source material for a consecutive enrichment cycle through the system 100 (shown schematically). Correspondingly, as illustrated in Figure 2A, method 200 may comprise opening the tube seal, separating the first crucible 120A containing concentrated product material from the second crucible 120B containing sublimated source material (stage 250), for example, by breaking the Petition 870250087577, dated 09 / 26 / 2025, page 32 / 82 24 / 33 sealing the tube, separating the first crucible 120A with concentrated 177Lu from the second crucible 120B with the sublimated Yb and repeating the stages of the method 210 - 250 (adjust 210, heat 220, irradiate 230, sublimate 240 and break 250) for several cycles, using the second crucible 120B with the sublimated source material from each cycle as the first crucible 120A with the source material for the next cycle (stage 260), for example, repeating stages 210 to 250 of the method for a plurality of cycles, using the second crucible 120B with the sublimated Yb from each cycle to prepare the first crucible 120A with Yb for the next cycle (see schematic illustration in Figure 1A, at the top of the illustration of handling unit 180). Alternatively, as illustrated in Figure 2B, the cyclic enrichment method 200 may involve opening the tube seal,Separating the bottom of the sealed tube (or the crucible contained therein) with the concentrated product material from the top of the sealed tube (or crucible therein) with the sublimated source material (stage 250A), for example, breaking the tube seal, separating the bottom of the tube with concentrated 177Lu from the top of the tube with the sublimated Yb, and repeating the stages of method 212-250A (deposit 212, heat 220, irradiate 230A, sublimate 240A, and break 250A) for multiple cycles, using the sublimated source material from the top of the tube from each cycle to provide the source material at the bottom of the tube for the next cycle (stage 260A), for example, repeating the stages of method 212-250A for a plurality of cycles, using the top of the tube with the sublimated Yb from each cycle for deposition in the bottom of the tube with Yb for the next cycle (see schematic illustration in Figure 1B, at the top of the illustration of handling unit 180).

[0055] It is observed that the tube can be ruptured in a specific environment, such as in an inert atmosphere, for example, of noble gases (e.g., Ar, He, Ne, Kr, Xe) or other inert gas or partial vacuum. Consequently, in some embodiments, the rupture 250 of the sealed tube can be carried out in an inert atmosphere. Petition 870250087577, dated 09 / 26 / 2025, p. 33 / 82 25 / 33

[0056] As normally less than 1% by weight of the source material is transformed into product material, the remaining source material (after sublimation of the first crucible 120A and solidification in the second crucible 120B) can be used as source material in the next cycle of the process, possibly without further processing. The second crucible 120B with the condensed source material can be removed from tube 110 and used as the first crucible 120A in the new tube 110 used in the consecutive cycle of the systems 100 and cyclic enrichment methods 200 disclosed, repeating the entire vacuum-tight connection process of the ampoule with the quartz tube of the vacuum system described above (stages 210 / 212, 215, 220), etc. This is a key advantage of the revealed target processing method – the absence of additional stages of handling expensive isotope-enriched ytterbium, which could lead to material loss or contamination.

[0057] The enrichment system 100 may further comprise a post-processing unit 190 configured to produce purified product material (e.g., 177Lu) from the concentrated product material of a plurality of enrichment cycles. Correspondingly, the cyclic enrichment method 200 may comprise post-processing the concentrated product material from the plurality of cycles to produce purified product material (stage 270), for example, post-processing the concentrated 177Lu from the plurality of cycles to produce purified 177Lu.

[0058] Post-processing can be used to remove impurities from non-volatile ytterbium compounds. For example, post-processing may comprise dissolving concentrated 177Lu (with the remaining 176Yb) in the first crucible 120A (or part of the tube) in hydrochloric and / or nitric acids (or combinations or mixtures thereof) and chromatographic purification. Additionally or complementarily, organophosphoric acids may be used, in particular, di-(2-ethylhexyl)-orthophosphoric acid (DEHPA or HDEHP) (structural formula 1), 2-ethylhexyl-2-ethylhexylphosphonic acid (HEH[EHP]) (structural formula 2), for example, Petition 870250087577, dated 09 / 26 / 2025, page 34 / 82 26 / 33 available under the trademarks LN resin and LN2 resin (Triskem ©), possibly after separation in hydrochloric acid solutions and / or extraction chromatography on an insoluble hydrophilic aliphatic polymer (e.g., acrylic ether). (2)

[0059] In certain embodiments, post-processing can be implemented as a multi-stage separation and purification (e.g., due to the significant difference in the amount of ytterbium and lutetium). In a non-limiting example, post-processing can be carried out in at least three separation stages: (i) separation of large amounts of ytterbium, (ii) primary isolation of 177Lu, and (iii) secondary (final) purification of the product. In all three stages, the separation can be carried out in the LN2 resin. In the transitions between stages, involving the desorption of lutetium (with ytterbium) from the column of the previous stage and its sorption in the column of the subsequent stage, the acidity differs significantly. The simplest way to remove the acid is to evaporate the solution. However, this is a long and time-consuming operation, which can be replaced by sorption, using TODGA (or DGA) resin as a sorbent.This resin contains tetraoctyldiglycolamide (structural formula 3), capable of absorbing REEs (rare earth elements) from strongly acidic solutions and retaining REEs weakly in dilute acidic solutions. Petition 870250087577, dated 09 / 26 / 2025, page 35 / 82 27 / 33

[0060] In a non-limiting experimental environment, the yield of 177Lu in this process reached 73%, and the total purification coefficient of ytterbium exceeded 106, which is sufficient for the production of 177Lu for pharmaceutical purposes. The total process time was approximately four hours, which is also a good indicator. In the case of using a combination of two steps: sublimation and chromatography, the extraction of 177Lu can be up to 90%, and the mass of processed ytterbium targets can be increased by up to several grams.

[0061] In several embodiments, the post-processing yield can be greater than 50%, 60%, 70%, 80% or intermediate values ​​(for extraction of product material, such as 177Lu from concentrated product material), and a total purification coefficient of the cyclic enrichment method 200 can be at least one million (106) - increasing the concentration of product material, such as 177Lu in the final product relative to the initial material.

[0062] In certain embodiments, enrichment systems 100 and / or cyclic enrichment methods 200 can be applied to metals and / or isotopes with very different boiling points, for example, to source material and product material with boiling points that differ (in °K) by at least 10%, 20%, 30%, 40%, 50%, intermediate values ​​or more. In non-limiting examples, the source material may be zinc and the product material may be copper, or the source material may be europium and the product material may be terbium.

[0063] Advantageously, certain modalities provide efficient production of lutetium-177 (177Lu), which is one of the most promising radionuclides for cancer therapy due to its unique radiochemical properties and the possibility of chemical binding with organic molecules. The modalities revealed surpass Petition 870250087577, dated 09 / 26 / 2025, page 36 / 82 28 / 33 Several difficulties of the previous technique in the production of this isotope. 177Lu is a radioactive isotope with a half-life T1 / 2 = 6.646 days, decaying with the emission of medium-energy beta and gamma radiation, as schematically illustrated in Figure 7A. 177Lu is obtained by neutron irradiation of the reactor starting material, which can be used as an isotope of lutetium-176 (176Lu) or ytterbium-176 (176Yb); however, of much greater practical interest is the production of 177Lu by irradiation of 176Yb. In the absence of other competing processes, irradiation of 176Yb leads to the formation of only one isotope of lutetium -177Lu. Therefore, this method allows obtaining a product with a specific activity corresponding to the theoretical value, i.e., 110 kCi / g. The dependence of the 177Lu yield (Ci per gram of initial 176Yb) on neutron fluxes of different densities is shown in Figure 7B.The dependencies do not have pronounced maxima in practically significant ranges of the irradiation cycle duration. This means that it is possible to choose the irradiation duration or the initial mass of the radionuclide according to a given performance. Even in a high-flux reactor, there is very low burn-up of the starting material. The relatively short half-life of the intermediate product of the accumulation of 177Lu-177Yb (T1 / 2 = 1.91 hours) allows the reuse of the starting material after exposure for the decay of this radionuclide in a few days. However, the actual activity of the irradiated material (therefore, the required exposure duration) is determined by the decay of other impurity isotopes. In any case, multiple uses of the starting material are possible, which is extremely important given the high price of material enriched with starting isotopes.

[0064] An equally important aspect is the isotopic composition of the starting material. The yield and specific activity calculations of 177Lu presented above were performed based on the assumption of 100% 176Yb content in the starting material. In practice, however, the ytterbium-176 oxide supplied by enrichment plants may have up to 2-3% of the 174Yb isotope. The presence of the 174Yb isotope in the starting composition leads to the accumulation of 175Yb (T1 / 2 = 4.18 d), which decays into 175Lu after the end of irradiation and therefore reduces the specific activity. Petition 870250087577, dated 09 / 26 / 2025, page 37 / 82 29 / 33 of 177Lu accumulated during irradiation. The effect of insufficiently high enrichment of the starting material is shown in Figure 7C. Calculations of the specific activity of 177Lu are presented for a model irradiation scheme in the SM-3 reactor (Atomic Reactor Research Institute, Dimitrovgrad, Russia), taking into account the actual duration of the reactor cycle, the operating time to extract the irradiated targets from the reactor and deliver them to the processing site, as well as the radiochemical processing itself. When the 174Yb content is greater than 1%, the specific activity of 177Lu during irradiation and subsequent post-reactor operations changes drastically and decreases to the value of the specific activity of 177Lu produced by the direct method (irradiation of 176Lu enriched with isotopes). In other words, the presence of 174Yb isotopic impurities in the starting material can, in the state of the art, lead to the production of a substandard product.This leads to the need to use starting material with the highest possible degree of enrichment, which, however, currently does not represent a major problem, since material with a 174Yb fraction of less than 0.2% is commercially available. It is also worth noting that, with repeated use (recycling) of the starting material, the 174Yb content decreases due to burning, that is, each successive irradiation cycle improves the quality of the starting material.

[0065] Depending on the irradiation conditions, the amount of 177Lu produced on the target varies from 0.05 to 0.3% (by weight). Assuming that the amount of ytterbium in the final product should not exceed 5% of the mass of lutetium (otherwise, the yield of the usable fraction during the synthesis of labeled compounds will decrease proportionally), then the separation factor of these two elements should be at least nd06. Since the electron shell structures of ytterbium and lutetium are extremely similar (the outer electron shell configuration 4f146s2e and 4f145d16s2, respectively), the separation of these two elements is an extremely difficult chemical task, as their chemical properties are very similar. Petition 870250087577, dated 09 / 26 / 2025, page 38 / 82 30 / 33

[0066] When separating ytterbium and lutetium in the +3 oxidation state, the separation is generally characterized by a low separation factor (coefficient). This leads to the need for multiple repetitions of the separation procedures, particularly due to the chromatographic design of the process. This approach is used for separation by extraction methods (extraction chromatography) or ion exchange (ion exchange chromatography).

[0067] The boiling points of metallic lutetium and metallic ytterbium are 3395°C and 1196°C, respectively. This characteristic can be used to separate lutetium and ytterbium. At high temperatures (above 400°C), the saturated vapor pressure of elemental metallic ytterbium significantly exceeds the saturated vapor pressure of elemental lutetium, which fundamentally allows their separation. However, this method has not yet become widely used due to the technical complexity of remotely handling radioactive substances in radiation shielding chambers. The separation must be carried out under vacuum, at temperatures above 400°C, and the materials of the device must be inert to ytterbium vapor.

[0068] The following is a non-limiting experimental example for carrying out the described procedure. 0.5 g of enriched metallic ytterbium containing more than 99% of the ytterbium-176 isotope (176Yb) was placed in a first niobium crucible 120A. The first ytterbium crucible 120A and a second empty crucible 120B were placed coaxially in a quartz tube, which was sealed at one end. The quartz tube was then coupled by its open end to sealing unit 150, which generated a vacuum below 10-2 kPa in the quartz tube by applying a vacuum pump 305. Heating and sealing of the tube were conducted by a hydrogen-oxygen torch from sealing unit 150. The sealed tube was then placed in an aluminum package and positioned in an irradiation channel inside the core of a nuclear reactor – and irradiated for 150 minutes. The packaging was then removed from the reactor and the sealed tube was extracted from the aluminum packaging.The amounts of lutetium-177 (177Lu) and ytterbium-175 (175Yb) were measured by their activity using spectrometry. Petition 870250087577, dated 09 / 26 / 2025, page 39 / 82 31 / 33 gamma and the generation of lutetium-177 (177Lu) within the tube was confirmed. The sealed tube was then delivered in a shielded container to the laboratory and placed in a sublimation unit 170 so that the end of the sealed tube with the first crucible 120A was heated by induction currents generated by a radio frequency (RF) coil of the sublimation unit 170. Temperature-controlled air was supplied to the opposite end of the sealed tube to control the accumulation of 176Yb at that end of the tube. Based on the brightness of the first crucible 120A, its temperature during the process ranged between 400°C and 1000°C, over the 60 minutes that the sublimation process was conducted. After sublimation, the sealed tube was broken within an argon bath and the first and second crucibles 120B were extracted from the broken tube.The sublimated and accumulated ytterbium material (in an amount exceeding 99% of the original mass) was collected in the second crucible 120B and subsequently sealed in a new tube as the new first crucible 120A – to repeat the irradiation and sublimation processes to generate more 177Lu. The residue inside the first crucible 120A was washed with 3M nitric acid and measured by gamma spectrometry to confirm the presence and quantity of lutetium (177Lu) as the product material. The amount of lutetium observed in the solution was confirmed as exceeding 90% of the amount calculated to be present in the sealed tube at the beginning of sublimation.

[0069] Advantageously, in relation to the prior art, such as WIPO Publication No. 2021102167, which uses a mobile cold finger to collect Yb vapor, the disclosed embodiments overcome the disadvantages of the prior art, such as (i) requiring a large volume of reaction apparatus, leading to a large amount of residual gas that can form non-volatile compounds with the ytterbium metal and interfere with the evaporation of the metal, (ii) lack of a simple and obvious way to collect and return the ytterbium collected in a cold finger to the sublimation cycle, and (iii) due to the small surface area of ​​the cold finger on which the ytterbium vapor condenses, some of the vapor may end up being in a finely dispersed form, which is pyrophoric and may explode upon contact with air. Petition 870250087577, dated 09 / 26 / 2025, page 40 / 82 32 / 33

[0070] Advantageously, the disclosed embodiments overcome the disadvantages of the prior art. For example, prior art, such as US Publication No. 20240011125, which utilizes a vacuum chamber with multiple passages and connections, presents the following disadvantages compared to the disclosed embodiments of the present invention. For example, the teaching of US Publication No. 20240011125 requires (i) sealing and pumping of the vacuum chamber before the start of the sublimation process, which takes a significant amount of time during which the product material, lutetium-177, is partially lost by radioactive decay; (ii) a dedicated, undisclosed process for collecting the separated ytterbium after each sublimation, which, besides being unclear and complex, also introduces additional material loss (ytterbium); and (iii) a dedicated pelletizing process for ytterbium, which requires additional effort and time to produce homogeneous targets and likely involves additional material losses.All of these issues are not required and / or resolved by the disclosed embodiments of the present invention, as explained above.

[0071] Advantageously, the disclosed modalities increase the useful yield of lutetium-177 radionuclides (increase the extraction of the radionuclide from the resulting material) by implementing direct (without intermediate steps) and highly efficient (yield greater than 90% by mass) recovery of enriched ytterbium material from the processed target. The disclosed modalities allow the separation of other metals and / or isotopes with very different boiling points, for example, zinc and copper, europium and terbium.

[0072] In the description above, an embodiment is an example or implementation of the invention. The various appearances of an embodiment, the embodiment, certain embodiments, or some embodiments do not necessarily refer to the same embodiments. Although several features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. On the other hand, although the invention may be described here in the context of embodiments Petition 870250087577, dated 09 / 26 / 2025, p. 41 / 82 33 / 33 separated for greater clarity, the invention can also be implemented in a single embodiment. Certain embodiments of the invention may include features from different embodiments disclosed above, and certain embodiments may incorporate elements from other embodiments disclosed above. Disclosure of elements of the invention in the context of a specific embodiment should not be interpreted as limiting its use only in that specific embodiment. Furthermore, it should be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in certain embodiments different from those disclosed in the description above.

[0073] The invention is not limited to these diagrams or the corresponding descriptions. For example, the flow need not move through each box or state illustrated, or in exactly the same order in which it is illustrated and described. The meanings of the technical and scientific terms used herein should be understood as being obvious to a person skilled in the art to which the invention pertains, unless otherwise defined. Although the invention has been described with respect to a limited number of embodiments, these should not be interpreted as limitations to the scope of the invention, but rather as examples of some of the preferred embodiments. Other possible variations, modifications, and applications are also within the scope of the invention. Consequently, the scope of the invention should not be limited by what has been described so far, but by the appended claims and their legal equivalents. Petition 870250087577, dated 09 / 26 / 2025, p. 42 / 82

Claims

1 / 14 CLAIMS 1. Enrichment system (100) characterized in that it comprises: a sealing unit (150) configured to heat and generate a vacuum in a tube (110, 300, 400, 406, 411, 415, 502, 503) and subsequently seal the tube (110, 300, 400, 406, 411, 415, 502, 503), wherein the tube (110, 300, 400, 406, 411, 415, 502, 503) is neutron permeable, heat resistant up to at least 600°C and includes a source material, an irradiation unit (160) configured to irradiate the source material in the tube (110, 300, 400, 406, 411, 415, 502, 503) sealed with neutrons to enrich the source material with a product material contained therein, a sublimation unit (170) configured to sublimate the source material in the sealed tube (110, 300, 400, 406, 411, 415, 502, 503) to concentrate the product material within the sealed tube (110, 300, 400, 406, 411, 415, 502, 503), and a handling unit (180) configured to break the sealing of the tube (110, 300, 400, 406,411, 415, 502, 503), separate the concentrated product material from the sublimated source material and use the sublimated source material as source material for a consecutive enrichment cycle through the system.

2. Enrichment system (100) according to claim 1, characterized in that the source material is deposited in a first section (110A) of the sealed tube (110, 300, 400, 406, 411, 415, 502, 503), from which the concentrated product material is collected, and the sublimated source material is collected within a second section (110B) of the sealed tube (110, 300, 400, 406, 411, 415, 502, 503).

3. Enrichment system (100) according to claim 2, characterized in that at least one of the first and second sections Petition 870250087577, dated 09 / 26 / 2025, page 43 / 82 2 / 14 comprises a corresponding crucible (301, 412, 416, 418) that is chemically inert to the respective source material and to the sublimated material.

4. Enrichment system (100) according to claim 3, characterized in that neither or one of the first and second sections comprises a crucible (301, 412, 416, 418) and the handling unit (180) is further configured to form a circular groove (506) in the sealed tube (110, 300, 400, 406, 411, 415, 502, 503) and subsequently break the tube (110, 300, 400, 406, 411, 415, 502, 503) along the groove to separate the concentrated product material from the sublimated parent material.

5. Enrichment system (100) according to claim 3, characterized in that both the first and second sections comprise corresponding crucibles (301, 412, 416, 418), arranged coaxially, in fluid communication through opposite open ends.

6. Enrichment system (100) according to claim 5, characterized in that the crucibles (301, 412, 416, 418) are made of niobium or its alloys, and the tube (110, 300, 400, 406, 411, 415, 502, 503) is made of quartz, niobium or its alloys, or aluminum or its alloys.

7. Enrichment system (100) according to claim 5, characterized in that the thickness of the side walls of the crucibles (301, 412, 416, 418) is less than 0.2 mm or within: 0.2-0.5 mm, 0.5-1 mm, 1-2 mm.

8. Enrichment system (100) according to claim 5, characterized in that the height of the crucibles (301, 412, 416, 418) is within any of the following: 3-100 mm, 3-30 mm, 30-100 mm.

9. Enrichment system (100) according to any one of claims 1 to 8, characterized in that the volume of the tube (110, 300, 400, 406, 411, 415, 502, 503) is at most: 100 ml, 30 ml, 10 ml or 3 ml.

10. Enrichment system (100) according to any one of claims 1 to 9, characterized in that the pressure inside the sealed tube (110, 300, 400, 406, 411, 415, 502, 503) is less than 100 kPa (1 bar) or Petition 870250087577, dated 09 / 26 / 2025, p. 44 / 82 3 / 14 within any of the following: 1 to 100 kPa, 10-2 to 1 kPa, 10-4 to 10-2 kPa, 10-6 to 10-4 kPa or 10-8 to 10-6 kPa.

11. Enrichment system (100) according to any one of claims 1 to 10, characterized in that the source material comprises ytterbium enriched in the isotope 176Yb in more than 90% by mass and the product material comprises 177Lu.

12. Enrichment system (100) according to any one of claims 1 to 11, characterized in that it further comprises a post-processing unit (190) configured to produce purified product material from concentrated product material from a plurality of enrichment cycles.

13. Enrichment system (100) according to claim 12, characterized in that the post-processing unit (190) is configured to dissolve the concentrated 177Lu in hydrochloric and / or nitric acids and to purify the 177Lu chromatographically.

14. Enrichment system (100) according to claim 12, characterized in that the yield of the post-processing unit (190) is greater than 60% and a total purification coefficient is at least one million.

15. Enrichment system (100) according to any one of claims 1 to 14, characterized in that the sublimation unit (170) is further configured to sublimate at least 99% by weight of the 176Yb from the source material, leaving at most 1% by weight of the 176Yb in the remaining 177Lu concentrate.

16. Enrichment system (100) according to any one of claims 1 to 15, characterized in that the sublimation unit (170) further comprises a heater (402) configured to heat the source material between 400°C and 1000°C, and a heat absorber (403) configured to maintain a sublimation unit (170) of the tube (110, 300, 400, 406, 411, 415, 502, 503) between 20°C and 300°C. Petition 870250087577, dated 09 / 26 / 2025, page 45 / 82 4 / 14 17. Enrichment system (100) according to any one of claims 1 to 16, characterized in that the sublimation (170) and handling (180) units are further configured to purify the source material before irradiation, sublimating the source material in the sealed tube (110, 300, 400, 406, 411, 415, 502, 503), removing non-volatile impurities that are left behind and using the purified source material for irradiation.

18. Method for producing 177Lu using the enrichment system (100) as defined in claim 1, characterized in that the method comprises: irradiating the 176Yb source material in the sealed tube (110, 300, 400, 406, 411, 415, 502, 503) with neutrons to enrich the source material with the 177Lu product material, sublimating the 176Yb from the irradiated source material to concentrate the 177Lu product material within the sealed tube (110, 300, 400, 406, 411, 415, 502, 503), and repeating the irradiation with the sublimated 176Yb as source material and the sublimation of the 176Yb from the irradiated source material – to further concentrate the product material. 177Lu.

19. Method according to claim 18, characterized in that it further comprises post-processing of the concentrated 177Lu product material.

20. Method according to claim 18 or 19, characterized in that the irradiation and sublimation are carried out inside the sealed tube (110, 300, 400, 406, 411, 415, 502, 503) without any crucible (301, 412, 416, 418).

21. Method according to any one of claims 18 to 20, characterized in that irradiation and sublimation are carried out on the source material within a crucible (301, 412, 416, 418) in a sealed tube (110, 300, 400, 406, 411, 415, 502, 503). Petition 870250087577, dated 09 / 26 / 2025, p. 46 / 82 5 / 14 22. Method according to any one of claims 18 to 21, characterized in that it further comprises collecting the 176Yb sublimated in another crucible (301, 412, 416, 418).

23. Method according to any one of claims 18 to 22, characterized in that it further comprises purifying the source material of non-volatile impurities prior to irradiation.

24. System for converting 176Yb to 177Lu, characterized in that the system comprises: a vacuum-sealed tube (110, 300, 400, 406, 411, 415, 502, 503); a first crucible (120A) comprising an open first end and having a 176Yb source material contained therein, positioned inside the sealed tube (110, 300, 400, 406, 411, 415, 502, 503); a second crucible (120B) comprising a second open end positioned within the sealed tube (110, 300, 400, 406, 411, 415, 502, 503), the second crucible (120B) being coaxially aligned and in fluid communication with the first crucible (120A) and positioned with the second open end opposite the first open end of the first crucible (120A);and an irradiation unit (160) configured to irradiate the 176Yb source material in the sealed tube (110, 300, 400, 406, 411, 415, 502, 503) with neutrons to produce a 177Lu product material, wherein the tube (110, 300, 400, 406, 411, 415, 502, 503) and both crucibles (120A, 120B) are made of neutron-transparent (permeable) material.

25. System according to claim 24, characterized in that: the crucibles (301, 412, 416, 418) are made of niobium and / or niobium alloys further comprising, in total, up to 50% by mass of at least one of: zirconium, tungsten, tantalum, titanium, nickel, and their combinations and / or alloys, Petition 870250087577, dated 09 / 26 / 2025, p. 47 / 82 6 / 14 the crucibles (301, 412, 416, 418) have a length between 10 and 50 mm, a diameter between 4 and 30 mm and a thickness of up to 2 mm, and the tube (110, 300, 400, 406, 411, 415, 502, 503) is made of quartz.

26. Method for preparing 177Lu product material from 176Yb source material, characterized in that the method comprises irradiating the 176Yb source material with neutrons in a vacuum-sealed tube (110, 300, 400, 406, 411, 415, 502, 503) to sublimate the 176Yb source material and produce the 177Lu product material, wherein the sealed tube (110, 300, 400, 406, 411, 415, 502, 503) comprises a first crucible (120A) comprising a first open end containing the 176Yb source material and a second crucible (120B) comprising a second open end positioned inside the tube (110, 300, 400, 406, 411, 415, 502, 503) sealed, wherein the first (120A) and second crucibles (120B) are coaxially aligned and in fluidic communication within the sealed tube (110, 300, 400, 406, 411, 415, 502, 503), with the second open end of the second crucible (120B) opposite the first open end of the first crucible (120A), and wherein the tube (110,300, 400, 406, 411, 415, 502, 503) and both crucibles (120A, 120B) are made of neutron-permeable material.

27. Method according to claim 26, characterized in that it further comprises: breaking the sealed tube (110, 300, 400, 406, 411, 415, 502, 503), separating the first crucible (120A) containing 177Lu from the second crucible (120B) containing the sublimated 176Yb, repeating the method for a plurality of cycles, using the second crucible (120B) containing the sublimated 176Yb from each cycle to prepare the first crucible (120A) containing 176Yb for a subsequent cycle, and purifying the concentrated 177Lu from the plurality of cycles to produce the purified 177Lu product. Petition 870250087577, dated 09 / 26 / 2025, p. 48 / 82 7 / 14 28. Method according to claim 27, characterized in that: the crucibles (301, 412, 416, 418) are made of niobium and / or niobium alloys further comprising, in total, up to 50% by mass of at least one of the following: zirconium, tungsten, tantalum, titanium, nickel, and their combinations and / or alloys; the crucibles (301, 412, 416, 418) have a length between 10 and 50 mm, a diameter between 4 and 30 mm and a thickness of up to 2 mm; and the tube (110, 300, 400, 406, 411, 415, 502, 503) is made of quartz.

29. Method according to claim 27 or 28, characterized in that the sublimation is carried out by heating the first crucible (120A) and condensing the sublimated 176Yb in a bottom of the second crucible (120B), opposite the second open end of the second crucible (120B).

30. Method according to claim 29, characterized in that it further comprises heating the first crucible (120A) between 400°C and 1000°C and maintaining a temperature of the second crucible (120B) between 20°C and 300°C, and wherein the sublimation is carried out between 10 minutes and 10 hours.

31. Method according to any one of claims 26 to 30, characterized in that the 176Yb sublimed in the second crucible (120B) includes at least 99% by weight of the 176Yb originally contained in the first crucible (120A), and the 177Lu concentrated in the first crucible (120A) includes at most 1% by weight of the 176Yb originally contained in the first crucible (120A).

32. Method according to any one of claims 26 to 31, characterized in that the purification comprises dissolving the 177Lu concentrate in the first crucible (120A) in hydrochloric and / or nitric acids and chromatographic purification.

33. Method according to any one of claims 26 to 32, characterized in that the purification yield is greater than 60% and the total purification coefficient is at least one million. Petition 870250087577, dated 09 / 26 / 2025, p. 49 / 82 8 / 14 34. Method according to any one of claims 26 to 33, characterized in that the 176Yb sublimed in the second crucible (120B) includes at least 99% by weight of the 176Yb originally in the first crucible (120A), and the 177Lu concentrated in the first crucible (120A) includes at most 1% by weight of the 176Yb originally contained in the first crucible (120A).

35. Method according to any one of claims 26 to 34, characterized in that it further comprises purifying the 176Yb source material of non-volatile impurities prior to irradiation.

36. Cyclic method for generating and separating 177Lu characterized in that it comprises: placing a first crucible (120A) with 176Yb coaxially opposite and in fluid communication with a second crucible (120B), with both crucibles (120A, 120B) contained within a tube (110, 300, 400, 406, 411, 415, 502, 503) and both crucibles (120A, 120B) and the tube (110, 300, 400, 406, 411, 415, 502, 503) being transparent (permeable) to neutrons, heating and generating a vacuum in the tube (110, 300, 400, 406, 411, 415, 502, 503) and, consecutively, seal the tube (110, 300, 400, 406, 411, 415, 502, 503), irradiate the 176Yb in the first crucible (120A) in the sealed tube (110, 300, 400, 406, 411, 415, 502, 503) with neutrons to generate 176Yb enriched with 177Lu in it, sublimate 176Yb from the first crucible (120A) to the second crucible (120B) to concentrate the 177Lu in the first crucible (120A), inside the sealed tube (110, 300, 400, 406, 411, 415, 502, 503), break the seal of the tube (110, 300, 400, 406, 411, 415, 502,503), separating the first crucible (120A) with concentrated 177Lu from the second crucible (120B) with sublimated 176Yb, repeating the aforementioned configuration, heating, irradiation, sublimation and disruption for a plurality of cycles, using the second crucible (120B) Petition 870250087577, dated 09 / 26 / 2025, page 50 / 82 9 / 14 with the sublimated 176Yb from each cycle to prepare the first crucible (120A) with 176Yb for the next cycle, and post-processing the concentrated 177Lu from the plurality of cycles to produce purified 177Lu., 37. Method according to claim 36, characterized in that: the crucibles (301, 412, 416, 418) are made of niobium and / or niobium alloys further comprising, in total, up to 50% by mass of at least one of: zirconium, tungsten, tantalum, titanium, nickel, and their combinations and / or alloys; the crucibles (301, 412, 416, 418) have a length between 10 and 50 mm, a diameter between 4 and 30 mm and a thickness of up to 2 mm; and the tube (110, 300, 400, 406, 411, 415, 502, 503) is made of quartz and is configured to be connected to a vacuum device (152) and then sealed after separation from the vacuum device (152), maintaining a vacuum. internal.

38. Method according to claim 36 or 37, characterized in that it further comprises the coaxial alignment of the crucibles (301, 412, 416, 418).

39. Method according to any one of claims 36 to 38, characterized in that the sublimation is carried out by heating the first crucible (120A) and condensing the sublimated 176Yb in a bottom of the second crucible (120B), opposite an opening thereof.

40. Method according to claim 39, characterized in that the heating of the first crucible (120A) is between 400°C and 1000°C and the temperature of the second crucible (120B) is maintained between 20°C and 300°C, and the sublimation is carried out between 10 minutes and 10 hours.

41. Method according to any one of claims 36 to 40, characterized in that the 176Yb sublimated in the second crucible (120B) Petition 870250087577, dated 09 / 26 / 2025, pp. 51 / 82 10 / 14 includes at least 99% by weight of the 176Yb originally contained in the first crucible (120A), and the 177Lu concentrated in the first crucible (120A) includes at most 1% by weight of the 176Yb originally contained in the first crucible (120A).

42. Method according to any one of claims 36 to 41, characterized in that the post-processing comprises dissolving the 177Lu concentrate in the first crucible (120A) in hydrochloric and / or nitric acids and chromatographic purification.

43. A method according to any one of claims 36 to 42, characterized in that the post-processing yield is greater than 60% and the total purification coefficient of the method is at least one million.

44. A method for any one of claims 36 to 43, characterized in that it further comprises purifying the 176Yb source material of non-volatile impurities prior to irradiation.

45. Cyclic enrichment method (200) characterized in that it comprises: placing a first crucible (120A) with a coaxially opposite source material in fluid communication with a second crucible (120B), with both crucibles (120A, 120B) contained within a tube (110, 300, 400, 406, 411, 415, 502, 503) and both crucibles (120A, 120B) and the tube (110, 300, 400, 406, 411, 415, 502, 503) being transparent (permeable) to neutrons, heating and generating a vacuum in the tube (110, 300, 400, 406, 411, 415, 502, 503) and, consecutively, seal the tube (110, 300, 400, 406, 411, 415, 502, 503), irradiate the source material in the first crucible (120A) of the sealed tube (110, 300, 400, 406, 411, 415, 502, 503) with neutrons to enrich the source material with a product material contained therein, sublimate the source material from the first crucible (120A) to the second crucible (120B) to concentrate the product material in the first crucible (120A), inside the tube (110, 300, 400, 406, 411, 415,502, 503) sealed, Petition 870250087577, dated 09 / 26 / 2025, page 52 / 82 11 / 14 break the sealing of the tube (110, 300, 400, 406, 411, 415, 502, 503), separating the first crucible (120A) with the concentrated product material from the second crucible (120B) with the sublimated source material, repeat the aforementioned configuration, heating, irradiating, sublimating and breaking a plurality of cycles, using the second crucible (120B) with the sublimated source material from each cycle to prepare the first crucible (120A) with the source material for the next cycle, and post-process the concentrated product material from the plurality of cycles to produce purified product material.

46. ​​Cyclic enrichment method (200) according to claim 45, characterized in that the source material comprises 176Yb and the product material comprises 177Lu.

47. Cyclic enrichment method (200) according to claim 45 or 46, characterized in that the source material and the product material have boiling points that differ by at least 20%.

48. Cyclic enrichment method (200) according to claim 47, characterized in that the source material is zinc and the product material is copper, or in that the source material is europium and the product material is terbium.

49. Enrichment system (100), according to claim 1, characterized in that it comprises: a sealing unit (150) configured to heat and generate vacuum in a tube (110, 300, 400, 406, 411, 415, 502, 503) and consecutively sealing the tube (110, 300, 400, 406, 411, 415, 502, 503), wherein the tube (110, 300, 400, 406, 411, 415, 502, 503) includes a first crucible (120A) with a coaxially opposed source material in fluid communication with a second crucible (120B), with both crucibles (120A, 120B) contained within the tube (110, 300, 400, 406, 411, 415, 502, 503) and both crucibles (120A, 120B) and the tube (110, 300, 400, 406, 411, 415, 502, 503) being transparent (permeable) to neutrons, Petition 870250087577, dated 09 / 26 / 2025, page 53 / 82 12 / 14 an irradiation unit (160) configured to irradiate the source material in the first crucible (120A) in the tube (110, 300, 400, 406, 411, 415, 502,503) sealed with neutrons to enrich the source material with a product material contained therein, a sublimation unit (170) configured to sublimate the source material from the first crucible (120A) to the second crucible (120B) to concentrate the product material in the first crucible (120A), inside the sealed tube (110, 300, 400, 406, 411, 415, 502, 503), a handling unit (180) configured to break the seal of the tube (110, 300, 400, 406, 411, 415, 502, 503), separate the first crucible (120A) with the concentrated product material from the second crucible (120B) with the sublimated source material and use the second crucible (120B) with the sublimated source material as the first crucible (120A) with the source material for a consecutive enrichment cycle through the system, and a post-processing unit (190) configured to produce purified product material from the concentrated product material of a plurality of enrichment cycles., 50. System (100) according to claim 49, characterized in that: the crucibles (301, 412, 416, 418) are made of niobium and / or niobium alloys further comprising, in total, up to 50% by mass of at least one of: zirconium, tungsten, tantalum, titanium, nickel, and their combinations and / or alloys; the crucibles (301, 412, 416, 418) have a length between 10 and 50 mm, a diameter between 4 and 30 mm and a thickness of up to 2 mm; and the tube (110, 300, 400, 406, 411, 415, 502, 503) is made of quartz and is configured to be connected to a vacuum device (152) and then sealed after separation from the vacuum device. (152), maintaining an internal vacuum. Petition 870250087577, dated 09 / 26 / 2025, pp. 54 / 82 13 / 14 51. System (100) according to claim 49 or 50, characterized in that the tube (110, 300, 400, 406, 411, 415, 502, 503) further comprises an alignment device (125) configured to keep the crucibles (301, 412, 416, 418) coaxially aligned.

52. System (100) according to any one of claims 49 to 51, characterized in that the sublimation unit (170) is configured to heat the first crucible (120A) and condense the sublimated 176Yb in a bottom of the second crucible (120B), opposite an opening thereof.

53. System (100) according to claim 52, characterized in that the heating of the first crucible (120A) is between 400°C and 1000°C and the temperature of the second crucible (120B) is maintained between 20°C and 300°C, and the sublimation is carried out between 10 minutes and 10 hours.

54. System (100) according to any one of claims 49 to 53, characterized in that the 176Yb sublimated in the second crucible (120B) includes at least 99% by weight of the 176Yb originally contained in the first crucible (120A), and the 177Lu concentrated in the first crucible (120A) includes at most 1% by weight of the 176Yb originally contained in the first crucible (120A).

55. System (100) according to any one of claims 49 to 54, characterized in that the post-processing unit (190) is configured to dissolve the 177Lu concentrated in the first crucible (120A) in hydrochloric and / or nitric acids and to purify the 177Lu chromatographically.

56. System (100) according to any one of claims 49 to 55, characterized in that the yield of the post-processing unit (190) is greater than 60% and a total purification coefficient is at least one million.

57. System (100) according to any one of claims 49 to 56, characterized in that the sublimation (170) and handling (180) units are further configured to purify the source material before irradiation, sublimating the source material in the sealed tube (110, 300, 400, 406, 411, Petition 870250087577, dated 09 / 26 / 2025, page 55 / 82 14 / 14 415, 502, 503), removing non-volatile impurities that are left behind and using the purified source material for irradiation.

58. System (100) according to claim 57, characterized in that the non-volatile impurities comprise at least one of the following: Lanthanum (La), Gadolinium (Gd), Erbium (Er), Thulium (Tm), including the decay product of Ytterbium-169, Hafnium (Hf) and / or Lutetium (Lu), including the decay product of Ytterbium-175. Petition 870250087577, dated 09 / 26 / 2025, pp. 56 / 82

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