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Boll, Rose Ann

Publications and source records attributed to Boll, Rose Ann.

10 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Microfluidics-based separation of actinium-225 from radium-225 for medical applications

Separation of 225 Ra (t 1/2 = 15 d) from its daughter isotope 225 Ac (t 1/2 = 10 d) is necessary to obtain pure 225 Ac for cancer alpha-therapy. In this study, microscale separation of 225 Ra from its daughter 225 Ac using BioRad AG50X4 cation exchange resin was achieved with good reproducibility across microdevices, and ≥90% purity was achieved for 225 Ac, which is comparable to conventional chromatography. These results indicate the potential for greater use of microfluidics for biomedical radiochemistry. The modularity of the system and its compatibility with different resins allows for quick and easy adaptation to the various needs of a separation campaign.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2017

Simultaneous Separation of Actinium and Radium Isotopes from a Proton Irradiated Thorium Matrix

A new method has been developed for the isolation of 223,224,225 Ra, in high yield and purity, from a proton irradiated 232 Th matrix. We report an all-aqueous process using multiple solid-supported adsorption steps including a citrate chelation method developed to remove >99.9% of the barium contaminants by activity from the final radium product. Moreover, we developed a procedure involving the use of three columns in succession, and the separation of 223,224,225 Ra from the thorium matrix was obtained with an overall recovery yield of 91 ± 3%, average radiochemical purity of 99.9%, and production yields that correspond to physical yields based on previously measured excitation functions.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2016

Effects of annealing temperature on morphology and thickness of samarium electrodeposited thin films

Electroplated depositions of Sm were prepared using a vertical well-type electrodeposition unit with an aqueous ammonium acetate electrolyte system, with an average deposition yield just over 87%. The depositions were analyzed for morphology and thickness by scanning electron microscopy (SEM) and chemical composition by energy dispersion X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) before and after firing. The depositions were fired at 125–700 °C, while varying the heating rate from 0.5 to 10 °C/min in either an oxidizing or reducing atmosphere. A heating rate of 10 °C/min was slow enough to prevent disruption of the deposition morphology during firing. Furthermore, a gas sweep enhanced the removal of any organic substituents, with an oxidizing environment being more advantageous than a reducing environment.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Reactor production of Thorium-229

Limited availability of 229 Th for clinical applications of 213 Bi necessitates investigation of alternative production routes. In reactor production, 229 Th is produced from neutron transmutation of 226 Ra, 228 Ra, 227 Ac and 228 Th. Here, we evaluate irradiations of 226 Ra, 228 Ra, and 227 Ac targets at the ORNL High Flux Isotope Reactor.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2015

Actinide targets for the synthesis of super-heavy elements

Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242 Pu, 244 Pu, 243 Am, 245 Cm, 248 Cm, 249 Cf, and 249 Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including 249 Bk, 251 Cf, and 254 Es are described.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Electrodeposition of actinide compounds from an aqueous ammonium acetate matrix. Experimental development and optimization

Electrodeposition is a technique that is routinely employed in nuclear research for the preparation of thin solid films of actinide materials which can be used in accelerator beam bombardments, irradiation studies, or as radioactive sources. The present study investigates the deposition of both lanthanides and actinides from an aqueous ammonium acetate electrolyte matrix. Electrodepositions were performed primarily on stainless steel disks; with yield analysis evaluated using -spectroscopy. Experimental parameters were studied and modified in order to optimize the uniformity and adherence of the deposition while maximizing the yield. The initial development utilized samarium as the plating material, with and without a radioactive tracer. As a result, surface characterization studies were performed by scanning electron microscopy, electron microprobe analysis, radiographic imaging, and x-ray diffraction.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2015

Californium Electrodepositions at Oak Ridge National Laboratory

Electrodepositions of californium isotopes were successfully performed at Oak Ridge National Laboratory (ORNL) during the past year involving two different types of deposition solutions, ammonium acetate (NH 4 C 2 H 3 O 2 ) and isobutanol ((CH 3 ) 2 CHCH 2 OH). A californium product that was decay enriched in 251 Cf was recovered for use in super-heavy element (SHE) research. This neutron-rich isotope, 251 Cf, provides target material for SHE research for the potential discovery of heavier isotopes of Z=118. The californium material was recovered from aged 252 Cf neutron sources in storage at ORNL. These sources have decayed for over 30 years, thus providing material with a very high 251 Cf-to- 252 Cf ratio. After the source capsules were opened, the californium was purified and then electrodeposited using the isobutanol method onto thin titanium foils for use in an accelerator at the Joint Institute for Nuclear Research in Dubna, Russia. Another deposition method, ammonium acetate, was used to produce a deposition containing 1.7 0.1 Ci of 252 Cf onto a stainless steel substrate. This was the largest single electrodeposition of 252 Cf ever prepared. The 252 Cf material was initially purified using traditional ion exchange media, such as AG50-AHIB and AG50-HCl, and further purified using a TEVA-NH 4 SCN system to remove any lanthanides, resulting in the recovery of 3.6 0.1 mg of purified 252 Cf. The ammonium acetate deposition was run with a current of 1.0 amp, resulting in a 91.5% deposition yield. Purification and handling of the highly radioactive californium material created additional challenges in the production of these sources.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2014

Californium purification and electrodeposition

The staff at the Radiochemical Engineering Development Center, located at Oak Ridge National Laboratory, produced a 6.3 ± 0.4 GBq (1.7 ± 0.1 Ci) 252 Cf source for the Californium Rare Isotope Breeder Upgrade (CARIBU) project at Argonne National Laboratory’s Argonne Tandem Linac Accelerator System. The source was produced by electrodeposition of a 252 Cf sample onto a stainless steel substrate, which required material free from excess mass for efficient deposition. The resulting deposition was the largest reported 252 Cf electrodeposition source ever produced. Several different chromatographic purification methods were investigated to determine which would be most effective for final purification of the feed material used for the CARIBU source. The separation of lanthanides from the Cf was of special concern. Furthermore, the separation, using 145 Sm, 153 Gd, and 249 Cf as tracers, was investigated using BioRad AG 50X8 in α-hydroxyisobutyric acid, Eichrom LN resin in both HNO 3 and HCl, and Eichrom TEVA resin in NH 4 SCN. The TEVA NH 4 SCN system was found to completely separate 145 Sm and 153 Gd from 249 Cf and was adopted into the purification process used in purifying the 252 Cf.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2014

Methods for separating medical isotopes using ionic liquids

A method for extracting a radioisotope from an aqueous solution, the method comprising: a) intimately mixing a non-chelating ionic liquid with the aqueous solution to transfer at least a portion of said radioisotope to said non-chelating ionic liquid; and b) separating the non-chelating ionic liquid from the aqueous solution. In preferred embodiments, the method achieves an extraction efficiency of at least 80%, or a separation factor of at least 1.times.10.sup.4 when more than one radioisotope is included in the aqueous solution. In particular embodiments, the method is applied to the separation of medical isotopes pairs, such as Th from Ac (Th-229/Ac-225, Ac-227/Th-227), or Ra from Ac (Ac-225 and Ra-225, Ac-227 and Ra-223), or Ra from Th (Th-227 and Ra-223, Th-229 and Ra-225).

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗