L. Keith Fifield

The timing of the last r-process event near Earth from interstellar 60Fe, 244Pu and 247Cm deposition on Earth

Dominik Koll, Sebastian Fichter, M.A.C. Hotchkis, S T Battisson et autres

Abstract Where are the heavy elements produced in the Universe? While core-collapse supernovae are confirmed sources of 60 Fe, the origin of heavier r-process nuclei such as 244 Pu and 247 Cm remains debated. Here we used single-atom counting of live 60 …

au, de (code pays fourni par la source)

Gas Detector Developments in AMS: Vertical position, total energy, and Bragg detector

Jackson T. H. Dowie, L. Keith Fifield, Stefan Pavetich, Stephen G. Tims

Gas ionisation chamber detectors are the workhorses of Accelerator Mass Spectrometry (AMS), providing essential isobar suppression and ion identification. Continued developments in detector resolution, performance, and reliability directly translate into improved AMS sensitivity and precision. In this contribution we report three recent …

au (code pays fourni par la source)

The Age and Origin of Block Deposits in the Victorian Alps, Australia

Timothy T. Barrows, Michelle S. Worland, Julian Murton, Stephanie Mills et autres

ABSTRACT Large periglacial block deposits are found in the mountains of southeastern Australia. Despite their widespread distribution, their mode of formation and age are poorly understood. These landforms hold considerable potential to shed light on the nature of cooling during glacial periods. …

au, gb (code pays fourni par la source)

Gas Detector Developments in AMS: Vertical position, total energy, and Bragg detector

Jackson T. H. Dowie, L. Keith Fifield, Stefan Pavetich, Stephen G. Tims

Gas ionisation chamber detectors are the workhorses of Accelerator Mass Spectrometry (AMS), providing essential isobar suppression and ion identification. Continued developments in detector resolution, performance, and reliability directly translate into improved AMS sensitivity and precision. In this contribution we report three recent …

au (code pays fourni par la source)

Technetium-99 determination in low-volume samples from the global environment with accelerator mass spectrometry

Karin Hain, Stephanie Adler, T. Faestermann, L. Keith Fifield et autres

The long-lived fission product technetium-99 ( 99 Tc, t 1/2 = (2.111± 0.012) × 10 5 years) was successfully detected in small-volume (10 L, and 1 g, respectively) environmental samples such as Pacific Ocean and river water, Antarctic snow, and peat.Its presence …

Record of ³H and ³⁶Cl from the Fukushima nuclear accident recovered from soil water in the unsaturated zone at Koriyama

Tomoko Ohta, L. Keith Fifield, László Palcsu, Stephen G. Tims et autres