Isoscaling parameters α and β have been explored as a function of breakup angle in binary excited projectile-like fragment decays produced in collisions of 70 Zn + 70 Zn and 64 Zn + 64 Zn at 35 MeV per nucleon. In this analysis, focus was placed on isoscaling the second heaviest fragment with 4 ≤ ZL ≤ 8 emitted from the excited projectile-like fragment in events that contained a heavy fragment with ZH ≥ 12. The breakup orientation θprox was defined as the angle between the heavy and light fragments' center of mass velocity and the fragment pairs' relative velocity. Breakups between 0 • < θprox ≤ 80 • have been shown to be dominated by dynamical contributions, while break-up angles of θprox > 100 • are predominantly statistical. Historically, isoscaling has often been understood and applied in a statistical context, assuming that the fragments are produced after statistical equilibrium is achieved. Studying isoscaling parameters as a function of θprox reveals the sensitivity of α and β to the mechanism of fragment production.

Ketones have been proven effective in extracting astatine­(III) from aqueous solvents. Previous theoretical studies suggested a mechanism where the “sp2” lone pair on the carbonyl oxygen donates electron density into the π system of the AtO+ molecular cation to form a dative-type bond. In this study, co-extraction of NO3 – as AtO­(NO3)·(OCR1R2) species into the organic phase appears to be a key factor. Adjusting the electronic properties of the ketone, by having an aryl group instead of an alkyl group in the alpha position of the ketone, increased the electron density on CO, increased the bond strength between the ketone and AtO+, and in turn increased the extraction of 211At into the organic phase. Extraction with diketones shows dependence on the bridging distance between the two carbonyl moieties, where a C3 or longer bridge results in a 10-fold increase in extraction into the organic phase. DFT calculations show the longer bridge allows for the chelation of AtO­(NO3) by either the second carbonyl or the phenyl ring.

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Alpha emitting radionuclides with medically relevant half-lives are interesting for treatment of tumors and other diseases because they deposit large amounts of energy close to the location of the radioisotope. Researchers at the Cyclotron Institute at Texas A&M University are developing a program to produce 211At, an alpha emitter with a medically relevant half-life. The properties of 211At make it a great candidate for targeted alpha therapy for cancer due to its short half-life (7.2 h). Astatine-211 has now been produced multiple times and reliability of this process is being improved.

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