Measurements of the Equivalent Dose in Aircraft with TLDs

For measurements of the equivalent dose of the mixed radiation fields in aircraft many different measuring devices are usually necessary for consideration of the different components of the radiation field. The possibility is discussed of using thermoluminescence dosemeters (TLDS) for determination of absorbed dose and average LET of this complex radiation field in aircraft. The HTR method, developed for determination of the equivalent dose in spacecraft, enables the measurement of the average LET in addition to the absorbed dose. Furthermore, a rem counter based on TLDs and a modified pair method (TLD-600, TLD-700) was used for determination of the absorbed dose due to the neutron component. Using small TLD crystals it is possible to obtain the depth distribution of absorbed dose and average LET by exposing TLDs in Bonner spheres with different diameters. The results indicate that the standards for determination of the effective dose may not be applicable in these mixed radiation fields in aircraft.