  We present experimental work for improved atom loading in the optical
molasses of a caesium fountain clock, employing a low-velocity intense source
of atoms (LVIS) [Lu et al., Phys. Rev. Lett. 77, 3331 (1996)], which we
modified by adding a "dark" state pump laser. With this modification the atom
source has a mean flux of $4 \times 10^{8}$ atoms/s at a mean atom velocity of
$8.6$ m/s. Compared to fountain operation using background gas loading, we
achieved a significant increase of the loaded and detected atom number by a
factor of 40. Operating the fountain clock with a total number of detected
atoms $N_{\mathrm{at}}=2.9 \times 10^6$ in the quantum projection noise-limited
regime, a frequency instability $\sigma_y\left(1\text{s}\right)=2.7 \times
10^{-14}$ was demonstrated.
