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
Kevin Roentgen co-produced with Noah Shain a project called Hott Mess, an album of 10 songs written and performed by Roentgen, Shain and singer Shayna Ross. In 2009, Croire en l'homme, was released as the b-side to the debut title track single from Johnny Hallyday's latest album, Ca n'finira jamais. Written by Roentgen and Oliver Leiber, the single debuted at #1 on the French Single Charts, the week of November 14, 2008, and remained number one for two weeks. Later that year, Roentgen produced the Light of Day EP for LA band, Analog Smith. In May 2012, Goldsboro, featuring Roentgen, Chris Cano