Advantages of introducing microdosimetric instruments and methods into radiation protection

The state of the art concerning the practical implementation of low-pressure proportional counters in radiation protection is described. Because of its approximate tissue equivalence, this counter is essentially an absorbed-dose measuring instrument. In addition, the pulse height information can be used to estimate dose equivalent. By a suitable choice of the counter wall and by appropriate calibration, the gas volume can be made to simulate a measurement of either dose equivalent at 10 mm depth in the ICRU sphere or effective dose equivalent. Finally this instrument measures the corresponding y-distributions which are closely related to LETsub(infinity) distributions. The implementation of these advantages to working area dosemeters, individual dosemeters and calibration standards is discussed. Particular attention is given to working area and environmental monitoring and the Juelich system developed for this purpose. (author)