  To realize and test advanced accelerator concepts and hardware, a beamline is
being reconfigured in the Linac Extension Area (LEA) of APS linac. A
photo-cathode RF gun installed at the beginning of the APS linac will provide a
low emittance electron beam into the LEA beamline. The thermionic RF gun beam
for the APS storage ring, and the photo-cathode RF gun beam for LEA beamline
will be accelerated through the linac in an interleaved fashion. In this paper,
the design studies for interleaving lattice realization in APS linac is
described with initial experiment result
