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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
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SEQUENCE:0
UID:UW-Physics-Event-2173
DTSTART:20110512T160000Z
DURATION:PT1H0M0S
DTSTAMP:20260420T120339Z
LAST-MODIFIED:20110422T130634Z
LOCATION:5310 Chamberlin
SUMMARY:Radioargon dating with Atom Trap Trace Analysis (detection of 
 39Ar at the part-per quadrillion level)\, Atomic Physics Seminar\, Wil
 l Williams\, Argonne National Lab
DESCRIPTION:Atom Trap Trace Analysis (ATTA)\, a laser-based atom count
 ing method\, has been used to analyze atmospheric 39Ar (half-life = 26
 9 yr)\, a cosmogenic isotope with an isotopic abundance of 0.8 parts-p
 er-quadrillion (8.x10-16). In addition to the superior selectivity dem
 onstrated in this work\, both the counting rate and counting efficienc
 y of ATTA have been improved by two orders of magnitude over prior res
 ults. Along with the previously demonstrated detection of 81Kr (229\,0
 00 yr) and 85Kr (10.8 yr) at the 10-12 level\, ATTA can now be used to
  analyze all three long-lived noble gas radioisotopes covering a wide 
 range of ages and applications.<br>
\n<br>
\nThis project is supported
  by DOE Nuclear Physics
URL:https://www.physics.wisc.edu/events/?id=2173
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