These condensation trails from photoelectrons were produced by an Iron-55 source (TEL-400XS) of 5.9 keV K-shell capture x-rays which was located below the photograph field, and slightly above the chamber's sensitive plane. The low energy x-rays interact with air through the photoelectric effect. Because the x-rays typically travel many centimeters before interacting, and the photoelectron range is much shorter, a fairly uniform array of dots were observed. Each dot was caused by a single photoelectron.