In a recent experiment performed with the EUROGAM II gamma-ray spectro
meter three superdeformed (SD) bands have been established in Ho-153.
The properties of these bands are discussed in terms of single-particl
e proton excitations and are compared with respect to the SD magic nuc
leus Dy-152. These results represent the first observation of SD struc
tures in a holmium nucleus and provide further information on the prot
on orbitals lying above the Z = 66 shell gap.