Liquid ionography for diagnostic radiology

In liquid ionography the x-ray photons are absorbed in a liquid containing a high-atomic-number atom, such as tetra-methyl-tin. The liquid is contained between two parallel electrodes separated by a few millimeters. Most of the ions produced in the liquid recombine. Those that escape recombination are collected on an insulating foil covering one of the electrodes. The resulting charge pattern is rendered visible using powder-cloud development. For a 4-mm electrode separation and using 45-kVp x rays, about 98% of the radiation is absorbed; for 105-kVp x rays, about 88% of the radiation is absorbed. We studied the sensitivity of a 4-mm chamber as a function of the applied electric field and found that, for 65-kVp x rays and an electric field of 70 kV/cm, the sensitivity is 1 nC/cm2-mR. We present an image of a test pattern with a resolution of better than 10 1p/mm produced by this system.