Roentgen (unit) One roentgen deposits of absorbed dose in dry air, or in soft tissue. One roentgen of X-rays may deposit anywhere from in bone depending on the beam energy. This tissue-dependent conversion from kerma to absorbed dose is called the F-factor in radiotherapy contexts. The conversion depends on the ionizing energy of a reference medium, which is ambiguous in the latest NIST definition. The roentgen has its roots in the Villard unit defined in 1908 by the American Roentgen Ray Society as "the quantity of radiation which liberates by ionisation one esu of electricity per cm of air under normal conditions
David Roentgen David Roentgen David Roentgen (1743 in HerrnhaagFebruary 12, 1807), was a famous German cabinetmaker of the eighteenth century, famed throughout Europe for his marquetry and his secret drawers and mechanical fittings. His work embraces the late Rococo and the Neoclassical styles. In 1753 his father Abraham Roentgen, who had trained in London in the workshop of William Gomm, migrated to the Moravian settlement at Neuwied, near Coblenz, where he established a furniture factory. David learned his trade in his father's workshop, inherited the paternal business in 1772, and entered into partnership with the clockmaker Kintzing. By that time, the name