STRUCTUR5 OF LOW-LYING ENERGY LEVELS OF HG-200

The decay scheme of Tl200→Hg200 has been reinvestigated with a Ge(Li) detector. The construction of the level scheme allows us to remove some of the ambiguities of previous investigations. From spectrum and angular-correlation measurements, the spin and parity of the 1029.5-keV third excited level of Hg200 is established as 0+. The low-energy level scheme of Hg200 is interpreted as due to the perturbation of the vibrational spectrum of bosons by a quadrupole interaction. © 1969 The American Physical Society.