Center for Quantum Electronics University of Texas at Dallas

Deexcitation of the 31-year isomer of 178Hf with Synchrotron Radiation (SR)

Comparison of results from significant experiments conducted in 2001


SPring-8, Hyogo, JAPAN


APS, Argonne, USA

X-ray spectrum Narrowband tunable; DE = 0.5 eV   "White"; DE = ~50,000 eV  
Target parentage

Virgin 75% of 1979 LANL spallation


Unknown beamstop


"Texas Group:" 15 scientists from 8 Labs in 5 Countries


"Argonne Consortium:" 15 scientists from 3 Labs in the US


All previous positive results CONFIRMED; 0.2% branch of photoionization at L1 and L3 ionization edges causes decay of isomeric state.


Totally negative results; all published positive reports CONTRADICTED.


Europhys. Lett. 57, 677 (2002)


PRL 87, 072503 (2001)


Please send comments and recommended revisions to:C.B. Collins