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
Dietrich Wilhelm Heinrich Busch Dietrich Wilhelm Heinrich Busch Dietrich Wilhelm Heinrich Busch (16 March 1788 – 15 March 1858) was a German obstetrician born in Marburg. In 1806 he earned his medical doctorate at the University of Marburg, becoming an associate professor of surgery in 1814. In 1817 he was appointed professor of obstetrics at Marburg, where from 1820 to 1829 he was director of the department of obstetrics. In 1829 he succeeded Adam Elias von Siebold (1775-1828) as professor and director of the obstetrics clinic at Friedrich Wilhelm University in Berlin, serving as university rector in 1835/36. He would remain as director of