  A pair of superconducting transverse deflecting RF cavities has been studied
in the QBA low emittance lattices of the 3 GeV TPS for generating ultra short
X-ray pulses. Three configurations with different locations for the two
cavities in a super-period of the TPS ring are investigated. During numerous
turns of the electron tracking, the nonlinear effects between the cavities, the
energy spread, the momentum compaction factor, and the synchrotron radiation
effects are taken into account. The configuration with positioning the RF
deflectors between the QBA cells in each super-period as an optimum arrangement
gives rise to better quality electron bunches and radiated photon pulses. The
FWHM of the radiated photon pulses of about 540 fs with an acceptable intensity
is attained by optimizing the compression optical elements of the TPS photon
beam line. Furthermore, the effects of the electron bunch length are studied by
alternatively employing an accelerating RF cavity operating with 1.1 MV and 3.0
MV, respectively. The operation of the accelerating RF cavity at 3.0 MV
improved the intensity of the photon pulses up to 30% and reduced the
equilibrium vertical emittance down to 70 pm-rad. The error tolerance for the
deflecting cavities, QBA lattice and injection process are also evaluated.
