  We report the discovery of nine previously unknown gamma-ray pulsars in a
blind search of data from the Fermi Large Area Telescope (LAT). The pulsars
were found with a novel hierarchical search method originally developed for
detecting continuous gravitational waves from rapidly rotating neutron stars.
Designed to find isolated pulsars spinning at up to kHz frequencies, the new
method is computationally efficient, and incorporates several advances,
including a metric-based gridding of the search parameter space (frequency,
frequency derivative and sky location) and the use of photon probability
weights. The nine pulsars have spin frequencies between 3 and 12 Hz, and
characteristic ages ranging from 17 kyr to 3 Myr. Two of them, PSRs J1803-2149
and J2111+4606, are young and energetic Galactic-plane pulsars (spin-down power
above 6e35 erg/s and ages below 100 kyr). The seven remaining pulsars, PSRs
J0106+4855, J0622+3749, J1620-4927, J1746-3239, J2028+3332, J2030+4415,
J2139+4716, are older and less energetic; two of them are located at higher
Galactic latitudes (|b| > 10 deg). PSR J0106+4855 has the largest
characteristic age (3 Myr) and the smallest surface magnetic field (2e11 G) of
all LAT blind-search pulsars. PSR J2139+4716 has the lowest spin-down power
(3e33 erg/s) among all non-recycled gamma-ray pulsars ever found. Despite
extensive multi-frequency observations, only PSR J0106+4855 has detectable
pulsations in the radio band. The other eight pulsars belong to the increasing
population of radio-quiet gamma-ray pulsars.
