scholarly journals Innovative Target for Production of Technetium-99m by Biomedical Cyclotron

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 25 ◽  
Author(s):  
Hanna Skliarova ◽  
Sara Cisternino ◽  
Gianfranco Cicoria ◽  
Mario Marengo ◽  
Vincenzo Palmieri
Keyword(s):  
Mechanical Stability ◽  
Gamma Spectroscopy ◽  
Target Material ◽  
Spectroscopy Analysis ◽  
Target Preparation ◽  
Technetium 99M ◽  
Backing Plate ◽  
Design And Manufacturing ◽  
Enriched Uranium ◽  
Beam Currents

Technetium-99m (99mTc) is the most used radionuclide worldwide in nuclear medicine for diagnostic imaging procedures. 99mTc is typically extracted from portable generators containing 99Mo, which is produced normally in nuclear reactors as a fission product of highly enriched Uranium material. Due to unexpected outages or planned and unplanned reactor shutdown, significant 99mTc shortages appeared as a problem since 2008 The alternative cyclotron-based approach through the 100Mo(p,2n)99mTc reaction is considered one of the most promising routes for direct 99mTc production in order to mitigate potential 99Mo shortages. The design and manufacturing of appropriate cyclotron targets for the production of significant amounts of a radiopharmaceutical for medical use is a technological challenge. In this work, a novel solid target preparation method was developed, including sputter deposition of a dense, adherent, and non-oxidized Mo target material onto a complex backing plate. The latter included either chemically resistant sapphire or synthetic diamond brazed in vacuum conditions to copper. The target thermo-mechanical stability tests were performed under 15.6 MeV proton energy and different beam intensities, up to the maximum provided by the available GE Healthcare (Chicago, IL, USA) PET trace medical cyclotron. The targets resisted proton beam currents up to 60 µA (corresponding to a heat power density of about 1 kW/cm2) without damage or Mo deposited layer delamination. The chemical stability of the proposed backing materials was proven by gamma-spectroscopy analysis of the solution obtained after the standard dissolution procedure of irradiated targets in H2O2.

Thermal-Mechanical Response of Non-Uniformly Heated LEU Foil Based Target

2011 ◽  
Author(s):  
Kyler K. Turner ◽  
Gary L. Solbrekken ◽  
Charlie W. Allen
Keyword(s):  
Mechanical Response ◽  
Metal Foil ◽  
Transfer Coefficients ◽  
Technetium 99M ◽  
Heat Transfer Coefficients ◽  
Plate Design ◽  
Enriched Uranium ◽  
Aluminum Plates ◽  
Sandwiched Structure ◽  
Global Threat

Technetium-99m is a diagnostic radiopharmaceutical that is currently used in 80% of the global nuclear diagnostic imaging procedures. The parent isotope for technetium-99m is molybdenum-99, most commonly obtained through the irradiation of high enriched uranium (HEU) targets. In accordance with the Department of Energy’s Global Threat Reduction Initiative (GTRI) an effort is underway to develop a process to produce molybdenum-99 using low enriched uranium (LEU) targets to maintain production yield relative to HEU targets. Conversion of targets to LEU material effectively mandates that the most efficient process is to cast LEU in the form of a metal foil as opposed to current powder based dispersion designs for HEU. Using a foil requires a significant modification to the current target design. One design concept uses an LEU foil sandwiched between two nominally flat aluminum plates. The LEU is enclosed in the sandwiched structure by welding the aluminum plates together about their edges. The plate design is inspired by high density monolithic LEU fuel plates with the exception that the LEU is not bonded to the aluminum plates nor is it necessary to clamp the plate edges to prevent lateral translation. The lack of bonding between the LEU foil and the plates allows the edges of the plate to be cut off so the foil can be removed after irradiation to be chemically processed. The un-heated edges of the plate target produce 3-D temperature gradients that induce plate deformations. This paper will review thermal mechanical response of an LEU foil based molybdenum-99 plate target geometry. This study describes the effect of various edge holding conditions, thermal loads, and heat transfer coefficients on the thermal-induced deflection and stress in the plates.

Thermal-Mechanical Response of Non-Uniformly Heated Nominally Flat and Curved LEU Foil Based Target

2012 ◽  
Author(s):  
Kyler K. Turner ◽  
Gary L. Solbrekken ◽  
Charlie W. Allen
Keyword(s):  
Mechanical Response ◽  
Three Dimensional ◽  
Department Of Energy ◽  
Transfer Coefficients ◽  
Technetium 99M ◽  
Plate Design ◽  
Enriched Uranium ◽  
Aluminum Plates ◽  
Sandwiched Structure ◽  
Global Threat

Technetium-99m is a radiopharmaceutical currently used in 85% of all diagnostic imaging procedures. The relative long lived parent isotope of technetium-99m is molybdenum-99, which is commonly produced by irradiating highly enriched uranium. In accordance with the Department of Energy: National Nuclear Security Administration’s Global Threat Reduction Initiative an effort is underway to develop low enriched uranium based molybdenum-99 production concepts. Achieving comparable molybdenum-99 yields in a low enriched uranium target effectively mandates the use of a high density metal low enriched uranium foil. Using a foil requires a significant modification to the current highly enriched uranium dispersion target designs. One design concept uses a low enriched uranium foil sandwiched between either two flat or curved aluminum plates. The low enriched uranium is enclosed in the sandwiched structure by welding the aluminum plates together about their edges. The plate design is inspired by low enriched uranium fuel plates with the exception that the low enriched uranium is not bonded to the aluminum plates nor is it necessary to clamp the plate edges to prevent lateral translation. The lack of bonding between the low enriched uranium foil and the plates allows easy removal of the foil after irradiation for chemically processing and separation. The un-heated edges of the plate target produce three-dimensional temperature gradients inducing deformations and stress. This paper will review the thermal mechanical response of a low enriched uranium foil based molybdenum-99 production target. This study describes the effect of various curvatures, thermal loads, and heat transfer coefficients on the thermal-induced deflection and stress.

scholarly journals Heavy-ion beam pumping as a model for nuclear-pumped lasers

1993 ◽  
Vol 11 (3) ◽  
pp. 509-519 ◽  
Author(s):  
A. Ulrich ◽  
B. Busch ◽  
W. Krötz ◽  
G. Ribitzki ◽  
J. Wieser ◽  
...  
Keyword(s):  
Ion Beam ◽  
Target Material ◽  
Heavy Ion ◽  
Rare Gas ◽  
Line Radiation ◽  
Time Resolved ◽  
High Pulse ◽  
Beam Currents ◽  
Almost All ◽  
Collisional Rate

Heavy-ion accelerators can provide various beams from protons to uranium ions with energies ranging from a few keV/u to more than 1 GeV/u. The Munich Tandem van de Graaff accelerator has been used for most of the experiments described in this article. It can provide continuous or pulsed beams of almost all elements with particle energies of about 3.5 MeV/u. The pulse width is typically 2 ns. Maximum DC-beam currents of the order of 10 μA can be obtained, for example, for 32S ions. When the beam is focused to a beam spot of about 3 mm diameter, the flux of the ions is comparable to the flux of fission fragments used for nuclear-pumped lasers. Ion beam pumping is therefore well suited for model experiments of nuclear-pumped lasers. Technical aspects of ion beam-pumped lasers are discussed and the results of the lasers that have thus far been pumped by this method aresummarized. As ion beams are available either continuous or at high-pulse repetition rates ranging from tens of kHz to MHz, detailed spectroscopic and time-resolved studies of the emission of light induced by heavy-ion excitation of the target material can easily be performed. Experiments in which the emission by rare gas excimers and line radiation from atoms and ions has been studied are described. Lifetime measurements of excited levels at different target densities were used to measure collisional rate constants.

scholarly journals Gamma spectroscopy analysis of archived Marshall Island soil samples

2015 ◽  
Vol 307 (3) ◽  
pp. 2563-2566
Author(s):  
S. Herman ◽  
K. Hoffman ◽  
K. Lavelle ◽  
A. Trauth ◽  
S. P. LaMont ◽  
...  
Keyword(s):  
Gamma Spectroscopy ◽  
Soil Samples ◽  
Spectroscopy Analysis ◽  
Marshall Island

Study of Synthesis of Nanoparticulate Zinc Oxide Aiming at the Confection of Appropriated Targets for the Production of Radioisotopes

2016 ◽  
Vol 881 ◽  
pp. 485-490
Author(s):  
Nelcy D.S. Mohallem ◽  
Juliana B. da Silva ◽  
Cristiana P. Rezende
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Gamma Spectroscopy ◽  
Low Cost ◽  
Average Particle Size ◽  
Average Particle ◽  
Radioisotope Production ◽  
Target Preparation ◽  
Multifunctional Material ◽  
Freeze Dried

Zinc Oxide (ZnO) is a multifunctional material, which produces radionuclides of gallium by irradiation, widely used in diagnosis and nuclear medicine. In this work, two precursors were tested as well as two routes of synthesis, with the objective of obtaining nanoparticles appropriate to the production of pellets with grain size and porosity suitable for target preparation used in the radioisotope production by irradiation. The sintered pellets obtained from zinc acetate and NH4OH, and freeze-dried presented density of 90% of the theoretical density, average particle size of 1 μm and macropore size of 500 nm. These targets generated radionuclide of gallium (67Ga and 66Ga) inside the pores, without rupture of the pellets, confirmed by gamma spectroscopy, at low cost of production.

ELECTRICAL, THERMAL AND MECHANICAL STABILITY OF AFM BSCCO-2223 COMPOSITE CONDUCTORS FOR CURRENT LEAD APPLICATIONS

2003 ◽  
Vol 17 (04n06) ◽  
pp. 477-483
Author(s):  
L. MARTINI
Keyword(s):  
Thermal Stability ◽  
Mechanical Stability ◽  
Mechanical Reinforcement ◽  
Technical Problems ◽  
Mechanical Characterisation ◽  
Composite Conductors ◽  
Current Leads ◽  
Design And Manufacturing ◽  
Technical Solutions ◽  
Thermal Stability Of

In this work, the relevant properties of AFM BSCCO-2223/AgAu composite conductors and the most crucial technical problems faced in the design and manufacturing of current leads (CLs) are presented and discussed. Important issues such as thermal stability of AFM conductors, their effective mechanical reinforcement and the viable technical solutions for kA-class CLs are addressed. AFM BSCCO-2223 composite conductors and kA-class AFM bundles went through an extensive electrical, thermal and mechanical characterisation in order to evaluate and possibly improve their overall performances and to increase their potential and range of application. Experimental results on ageing tests on AFM specimens, with and without mechanical reinforcement, after thermal cycling in liquid nitrogen and quench experiments, induced by overcurrents and/or lacking of cooling, are reported and discussed in detail.

Portable Non-Destructive Assay Methods for Screening and Segregation of Radioactive Waste

2010 ◽  
Author(s):  
Alan Simpson ◽  
Stephanie Jones ◽  
Martin Clapham ◽  
Randy Lucero
Keyword(s):  
High Resolution ◽  
Radioactive Waste ◽  
Gamma Spectroscopy ◽  
Fission Products ◽  
Cost Savings ◽  
Assay Method ◽  
Waste Streams ◽  
Enriched Uranium ◽  
Non Destructive

Significant cost-savings and operational efficiency may be realised by performing rapid non-destructive classification of radioactive waste at or near its point of retrieval or generation. There is often a need to quickly categorize and segregate bulk containers (drums, crates etc.) into waste streams defined at various boundary levels (based on its radioactive hazard) in order to meet disposal regulations and consignor waste acceptance criteria. Recent improvements in gamma spectroscopy technologies have provided the capability to perform rapid in-situ analysis using portable and hand-held devices such as battery-operated medium and high resolution detectors including lanthanum halide and high purity germanium (HPGe). Instruments and technologies that were previously the domain of complex lab systems are now widely available as touch-screen “off-the-shelf” units. Despite such advances, the task of waste stream screening and segregation remains a complex exercise requiring a detailed understanding of programmatic requirements and, in particular, the capability to ensure data quality when operating in the field. This is particularly so when surveying historical waste drums and crates containing heterogeneous debris of unknown composition. The most widely used portable assay method is based upon far-field High Resolution Gamma Spectroscopy (HRGS) assay using HPGe detectors together with a well engineered deployment cart (such as the PSC TechniCART™ technology). Hand-held Sodium Iodide (NaI) detectors are often also deployed and may also be used to supplement the HPGe measurements in locating hot spots. Portable neutron slab monitors may also be utilised in cases where gamma measurements alone are not suitable. Several case histories are discussed at various sites where this equipment has been used for in-situ characterization of debris waste, sludge, soil, high activity waste, depleted and enriched uranium, heat source and weapons grade plutonium, fission products, activation products, americium, curium and other more exotic nuclides. The process of acquiring and analyzing data together with integration of historical knowledge to resolve and delineate waste streams (for example between low-level waste and transuranic waste) is described.

scholarly journals Synthesis and Characterization of Molybdenum Phthalocyanine as Target Material for High Specific Activity Molybdenum-99 Production

2019 ◽  
Vol 19 (3) ◽  
pp. 556 ◽  
Author(s):  
Muhamad Basit Febrian ◽  
Duyeh Setiawan ◽  
Hilda Hidayati
Keyword(s):  
Optimum Condition ◽  
Trifluoroacetic Acid ◽  
Specific Activity ◽  
High Specific Activity ◽  
Target Material ◽  
Radioisotope Generators ◽  
Promising Target ◽  
Band Absorption ◽  
Enriched Uranium

High specific activity is a necessity in the fabrication of 99Mo/99mTc radioisotope generators. Recoil reaction, or the Szilard-Chalmers effect, is a method that could be used as an alternative method for increasing specific activity in radioisotope production in light of tightening regulation of highly enriched uranium (HEU) irradiation. Phthalocyanine compounds are usually used as the target material in recoil reactions for the production of high specific radioisotope activity via the (n,γ) reaction. Molybdenum phthalocyanine (Mo-Pc) could be a promising target material in recoil reactions for producing high specific activity of 99Mo. Mo-Pc was synthesized via solid-state reaction between ammonium heptamolybdate and phthalonitrile in a reflux system at 300 °C for 3 h. This optimum condition was identified after performing several variations of temperature and time of reaction, considering FTIR spectra, the yield of product and melting point of the product. XRD measurement showed that Mo-Pc synthesized at optimum condition was free from MoO2, phthalimide and unreacted molybdenum. Mo-Pc has UV-vis properties of Q-band absorption between 600 and 750 nm when dissolved in tetrahydrofuran, dimethylformamide and trifluoroacetic acid. Splitting at absorption peak in tetrahydrofuran and dimethylformamide solution indicated that protonation had occurred. This split peak did not appear in a trifluoroacetic acid solution. In the preliminary study of irradiation of 1 g Mo-Pc at 3.5x1012 n cm–2 s–1 neutron flux, followed by dissolution in tetrahydrofuran and extraction of Mo-99 into NaOH, we obtained Mo-99 solution with a specific activity of 682.35 mCi/g Mo, this being 254.61 times higher than in the regular MoO3 target.

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