Small-animal tomography with a liquid-metal-jet x-ray source

X-ray tomography of small animals is an important tool for medical research. For high-resolution x-ray imaging of few-cm-thick samples such as, e.g., mice, high-brightness x-ray sources with energies in the few-10-keV range are required. In this paper we perform the first small-animal imaging and tomography experiments using liquid-metal-jet-anode x-ray sources. This type of source shows promise to increase the brightness of microfocus x-ray systems, but present sources are typically optimized for an energy of 9 keV. Here we describe the details of a high-brightness 24-keV electron-impact laboratory microfocus x-ray source based on continuous operation of a heated liquid-In/Ga-jet anode. The source normally operates with 40 W of electron-beam power focused onto the metal jet, producing a 7x7 mu m(2) FWHM x-ray spot. The peak spectral brightness is 4x10(9) photons/(sxmm(2)xmrad(2)x0.1%BW) at the 24.2 keV In K-alpha line. We use the new In/Ga source and an existing Ga/In/Sn source for high-resolution imaging and tomography of mice.