Proposed Measurement of the 242mAm(n,g) cross section using DANCE/LANSCE

Radiochemists at LLNL have produced a 98{\%} enriched sample of $^{242m}$Am (t$_{1/2}$ = 141 y) via $^{241}$Am(n,g) in the Hi-Flux reactor at ORNL and subsequent calutron enrichment. The availability of such a rare sample provides a unique opportunity to study properties of $^{242m}$Am . A proposal has been submitted to use the DANCE array at the LANSCE to measure the (n,g) cross section on the $^{242m}$Am isomer. At DANCE, capture cross sections can be measured for neutron energies ranging from thermal to about 100 keV on milligram-size radioactive targets. LLNL and LANL collaborators are currently working to build and install a fission-tagging detector in DANCE. With this extended capability, fission and capture events can be discriminated, leading to a better signal-to-noise ratio for the (n, g) measurement and enabling a simultaneous measurement of the (n,f) cross section. Progress on the implementation of the fission-tagging detector at DANCE and details of the proposed $^{242m}$Am(n,g) experiment will be presented. *Work performed under the auspices of the U.S.DOE. by the University of California, LLNL, and LANL under contracts W-7405-ENG-48 and W-7405-ENG-36.