Oak Ridge National Laboratory

Physics Division

Physics Division Seminars

Physics Division Seminars bring us speakers on a variety of physics related subjects. Usually these are held in the Building 6008 large Conference Room, at 3:00 pm on the chosen day, but times and locations may vary. For more information, contact our seminar chairman,

Alfredo Galindo-Uribarri
Tel (Office): (865) 574-6124  (FAX): (865) 574-1268


Fri., May 23, 2014, at 11:00 am - 12:00 PM (refreshments at 10:40 PM)

Actinides & AMS: Nuclear (Astro) Physics and Environmental Applications

Anton Wallner, Australian National University, Canberra, ACT 0200 Australia
ORNL, Bldg. 6008 Large Conference Room

Accelerator mass spectrometry (AMS) represents a direct atom-counting technique with unsurpassed sensitivity for studying long-lived radionuclides. In this talk, I will highlight some AMS applications involving actinides:

(i) The search for live supernova-produced radionuclides in terrestrial archives. Such studies probe directly specific nucleosynthesis sites and will help understanding heavy element nucleosynthesis in massive stars. Interstellar 244Pu (t1/2 = 81 Myr) is a perfect nuclide to study r-process nucleosynthesis that serves also as a probe for r-process sites.

(ii) Improved and highly accurate nuclear data are urgently required for the design of advanced reactor concepts. Neutron activation with subsequent AMS measurement of the reaction products represents a new independent and complementary method. Such data serve as important anchor points to solve present discrepancies as well as impact on data used in the nuclear astrophysics community.

(iii) The concentrations of actinides in our environment provide unique information and can give valuable information on its sources. Their isotopic fingerprint allows tracing anthropogenic activities (e.g., from nuclear weapons tests, accidental local fallout products, nuclear-fuel reprocessing plants) or environmental processes (soil erosion, climate change).

Contact: Alfredo Galindo-Uribarri, (865) 574-6124