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Barrett, Kendall E.

Publications and source records attributed to Barrett, Kendall E..

7 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Cyclotron production of 43Sc and 44gSc from enriched 42CaO, 43CaO, and 44CaO targets

Introduction: 43 Sc and 44g Sc are both positron-emitting radioisotopes of scandium with suitable half-lives and favorable positron energies for clinical positron emission tomography (PET) imaging. Irradiation of isotopically enriched calcium targets has higher cross sections compared to titanium targets and higher radionuclidic purity and cross sections than natural calcium targets for reaction routes possible on small cyclotrons capable of accelerating protons and deuterons. Methods: In this work, we investigate the following production routes via proton and deuteron bombardment on CaCO 3 and CaO target materials: 42 Ca(d,n) 43 Sc, 43 Ca(p,n) 43 Sc, 43 Ca(d,n) 44g Sc, 44 Ca(p,n) 44g Sc, and 44 Ca(p,2n) 43 Sc. Radiochemical isolation of the produced radioscandium was performed with extraction chromatography using branched DGA resin and apparent molar activity was measured with the chelator DOTA. The imaging performance of 43 Sc and 44g Sc was compared with 18 F, 68 Ga, and 64 Cu on two clinical PET/CT scanners. Discussion: The results of this work demonstrate that proton and deuteron bombardment of isotopically enriched CaO targets produce high yield and high radionuclidic purity 43 Sc and 44g Sc. Laboratory capabilities, circumstances, and budgets are likely to dictate which reaction route and radioisotope of scandium is chosen.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Excitation function of 54 Fe(p, α ) 51 Mn from 9.5 MeV to 18 MeV

Excitation function of the 54 Fe(p,α) 51 Mn reaction was measured from 9.5 to 18 MeV $E_{0,p^+}$ by activating a foil stack of 54 Fe electrodeposited on copper substrates. Residual radionuclides were quantified by HPGe gamma ray spectrometry. Both 51 Mn ($t_{1/2}$ = 46.2 min, $\langle E_{β^+}\rangle$=963.7keV, $I_{β^+}$ = 97%; $E_γ$ = 749.1keV, $I_γ$ = 0.265%) and its radioactive daughter, 51 Cr ($t_{1/2}$ = 27.704d, $E_γ$ = 320.1 keV, $I_γ$ = 9.91%), were used to indirectly quantify formation of 51 Mn. Results agree within uncertainty to the only other measurement in literature and predictions of default TALYS theoretical code. Final relative uncertainties are within ±12%.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

A heavy-ion production channel of 149 Tb via 63 Cu bombardment of 89 Y

We report the radionuclide 149 Tb (t 1/2 = 4.1 h) is a potential theranostic isotope which can simultaneously be used for targeted-alpha-particle therapy and positron-emission tomography. Feasibility experiments were performed to test a near-symmetric heavy-ion reaction of 63 Cu bombardment on monoisotopic 89 Y. The indirect reaction was studied to avoid isomer production. Offline gamma spectroscopy was used to quantify thick-target physical yields and experimental results show modest agreement to the fusion-evaporation code PACE4. A near-symmetric fission yield was also observed.

149Tb↗
DOE OSTI2021

Production, Purification, and Applications of a Potential Theranostic Pair: Cobalt-55 and Cobalt-58m

The emerging success of [68Ga/177Lu]Ga/Lu-DOTATATE as a theranostic pair has spurred interest in other isotopes as potential theranostic combinations. Here, we review cobalt-55 and cobalt-58m as a potential theranostic pair. Radionuclidically pure cobalt-55 and cobalt-58m have been produced on small cyclotrons with high molar activity. In vitro, DOTATOC labeled with cobalt has shown greater affinity for SSTR2 than DOTATOC labeled with gallium and yttrium. Similarly, [58mCo]Co-DOTATATE has shown improved cell-killing capabilities as compared to DOTATATE labeled with either indium-111 or lutetium-177. Finally, PET imaging with an isotope such as cobalt-55 allows for image acquisition at much later timepoints than gallium, allowing for an increased degree of biological clearance of non-bound radiotracer. We discuss the accelerator targetry and radiochemistry used to produce cobalt-55,58m, emphasizing the implications of these techniques to downstream radiotracers being developed for imaging and therapy.

60 APPLIED LIFE SCIENCES↗