Interstellar ^{60}Fe in Antarctica.

Earth is constantly bombarded with extraterrestrial dust containing invaluable information about extraterrestrial processes, such as structure formation by stellar explosions or nucleosynthesis, which could be traced back by long-lived radionuclides. Here, we report the very first detection of a recent ^{60}Fe influx onto Earth by analyzing 500 kg of snow from Antarctica by accelerator mass spectrometry. By the measurement of the cosmogenically produced radionuclide ^{53}Mn, an atomic ratio of ^{60}Fe/^{53}Mn=0.

Ultratrace Determination of Tc in Small Natural Water Samples by Accelerator Mass Spectrometry with the Gas-Filled Analyzing Magnet System.

In the frame of studies on the safe disposal of nuclear waste, there is a great interest for understanding the migration behavior of Tc. Tc originating from nuclear energy production and global fallout shows environmental levels down to 10 atoms/g of soil (∼2 fg/g). Extremely low concentrations are also expected in groundwater after diffusion of Tc through the bentonite constituting the technical barrier for nuclear waste disposal.

Assessment of Mn deposition on Earth via accelerator mass spectrometry.

The Mn flux onto Earth is a quantity relevant for different extraterrestrial and astrophysical questions. It is a proxy for related fluxes, such as supernova-produced material or interplanetary dust particles. In this work, we performed a first attempt to assess the Mn flux by measuring the Mn/Be isotopic ratio in a 1400 L sample of molten Antarctic snow by AMS (Accelerator Mass Spectrometry).

Plutonium Isotopes (Pu) Dissolved in Pacific Ocean Waters Detected by Accelerator Mass Spectrometry: No Effects of the Fukushima Accident Observed.

The concentration of plutonium (Pu) and the isotopic ratios of Pu to Pu and Pu to Pu were determined by accelerator mass spectrometry (AMS) in Pacific Ocean water samples (20 L each) collected in late 2012. The isotopic Pu ratios are important indicators of different contamination sources and were used to identify a possible release of Pu into the ocean by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. In particular, Pu is a well-suited indicator for a recent entry of Pu because Pu from fallout of nuclear weapon testings has already significantly decayed.

Time-resolved 2-million-year-old supernova activity discovered in Earth's microfossil record.

Massive stars ([Formula: see text]), which terminate their evolution as core-collapse supernovae, are theoretically predicted to eject [Formula: see text] of the radioisotope (60)Fe (half-life 2.61 Ma). If such an event occurs sufficiently close to our solar system, traces of the supernova debris could be deposited on Earth.

Separation of samarium and neodymium: a prerequisite for getting signals from nuclear synthesis.

(146)Sm (T(1/2) = 10(8) y) is a long-lived radionuclide which has been produced in significant amounts during burning in a supernova (SN). Detection of this SN produced long-lived radionuclide on Earth may be helpful for getting information on nuclear synthesis at the time of our solar system's formation. Only accelerator mass spectrometry (AMS) can determine such minute traces of (146)Sm still expected in the Earth's crust.

Separation of no-carrier-added 52Mn from bulk chromium: a simulation study for accelerator mass spectrometry measurement of 53Mn.

53Mn radionuclide (T(1/2) = 3.7 x 10(6) y) is produced through the interaction of cosmic rays. Measurements of concentrations of 53Mn in rocks might help to understand Earth surface processes that occurred in time periods not accessible with other cosmogenic nuclides.

Separation of trace level hafnium from tungsten: a step toward solving an astronomical puzzle.

182Hf (T(1/2) = 9 x 10(6) y) is believed to be formed by pure r-process during a supernova explosion, and therefore, the search for minute traces of 182Hf in the earth's crust is of great interest. Only accelerator mass spectrometry (AMS) is well suited for detecting such low levels of 182Hf. But any attempt to measure 182Hf by AMS must ensure that the sample is free from its naturally occurring stable isobar 182W.