  We report enhanced three-dimensional degenerated Raman sideband cooling (3D
DRSC) of caesium (Cs) atoms in a standard single-cell vapour-loading
magneto-optical trap. Our improved scheme involves using a separate repumping
laser and optimized lattice detuning. We load $1.5 \times 10^7$ atoms into the
Raman lattice with a detuning of -15.5 GHz (to the ground F = 3 state).
Enhanced 3D DRSC is used to cool them from 60 $\mu$K to 1.7 $\mu$K within 12 ms
and the number of obtained atoms is about $1.2 \times 10^7$. A theoretical
model is proposed to simulate the measured number of trapped atoms. The result
shows good agreement with the experimental data. The technique paves the way
for loading a large number of ultracold Cs atoms into a crossed dipole trap and
efficient evaporative cooling in a single-cell system.
