Dr. Günther Dietze passed away in January 2015. He was very highly regarded within the ICRU and made significant contributions to its work, in particular in the field of metrology of ionizing radiation. For many years he was a member of the ICRU Standing Committee on Fundamental Quantities and Units which published a few years ago ICRU Report 85a on Fundamental Quantities and Units for Ionizing Radiation, the basis for metrology of all applications of ionizing radiation. Günther Dietze assisted the ICRU in preparing a number of other reports concerning dosimetry of ionizing radiation, including Report 47, Measurement of Dose Equivalents from External Photon and Electron Radiation and Report 57, Conversion Coefficients for Use in Protection against External Radiation. More recently and until his untimely death he was engaged working on a committee report on operational quantities for external radiation. 

Due to his exceptional scientific reputation, his outstanding analytical and conceptual competence as well as his communication skills, Günther Dietze was invited to serve on numerous national and international scientific and advisory committees. From 1990 to 2004 he was member, and 2001 to 2003 chairman, of the German Radiation Protection Commission, advising the German Government. From 1993 to 2013 he was a member of ICRP Committee 2. He made major contributions to the work of its Task Groups and to ICRP publication 103, The 2007 Recommendations of the International Commission on Radiological Protection. He was chairman of the ICRP Task Group that prepared ICRP publication 123, Assessment of Radiation Exposure of Astronauts in Space. In the years 1991 to 2001 he was the chairman of EURADOS (European Radiation Dosimetry Group). 

In 1968 Günther Dietze graduated with a Ph.D. in physics from the University Hamburg. He joined PTB (Physikalisch-Technische Bundesanstalt), the German national metrology laboaratory, in 1970. His main field of interest initially was the dosimetry of neutrons but was involved in the dosimetry of ionizing radiation in all fields of their application including medicine, radiation protection and in industry. In 1989 he became the Head of PTB’s Department on Ionizing Radiation, a position he held until his retirement in 2001. Günther Dietze’s scientific and conceptual contribution to the field of metrology of ionizing radiation is also documented by his more than 140 publications in scientific journals. 

Günther Dietze was a devoted family man. He is survived by his wife Inge, his son and daughter and 6 grandchildren. A large circle of both professional and private friends appreciated his warmth and dry sense of humor as well as his unfailing social commitment and reliability. He will be missed by us all.

Hans Menzel, Chairman
Paul DeLuca, Vice Chairman