  We demonstrate the highest flux tabletop source of coherent soft X-rays to
date, driven by a single-stage 10 mJ Ti:sapphire regenerative amplifier at 1
kHz. We first down-convert the laser to 1.3 um using a parametric amplifier,
before up-converting it to soft X-rays using high harmonic generation in a
high-pressure, phase matched, hollow waveguide geometry. The resulting
optimally phase matched broadband spectrum extends to 200 eV, with a soft X-ray
photon flux of > 10^6 photons/pulse/1% bandwidth at 1 kHz, corresponding to >
10^9 photons/s/1% bandwidth, or approximately a three order-of-magnitude
increase compared with past work. Finally, using this broad bandwidth X-ray
source, we demonstrate X-ray absorption spectroscopy of multiple elements and
transitions in molecules in a single spectrum, with a spectral resolution of
0.25 eV, and with the ability to resolve the near edge fine structure.
