caa a22 4500 397503822 CHVBK 20180308164539.0 cr unu---uuuuu 161202e19950801xx s 000 0 eng 10.1093/oxfordjournals.rpd.a082785 doi 0144-8420 pii (NATIONALLICENCE)oxford-10.1093/oxfordjournals.rpd.a082785 A Feasability Study of Scintillator Microdosemeters for Measurement of the Biological Effectiveness of Ionising Radiations [Elektronische Daten] [D.E. Watt, A.S. Alkharam] Double-strand breaks in the intranuclear DNA are generally considered to be the precursors leading to the deleterious effects of ionising radiations in mammalian cells. If instrumentation can be designed with a detection response which simulates that of the DNA in cells then there is the possibility of developing a unified system of dosimetry which will be independent of radiation type. Interactions in site sizes of nanometre dimensions are involved. Active centres in the crystalline lattice of a scintillator, or the fluor solute in a plastic phosphor, have interaction cross sections for light emission which are typically a few nanometres squared. By adjusting the concentration of the activator, the mean of the random distance between centres can be modified to simulate the strand-pair distributions of the DNA in mammalian cells. To simulate the yield of initial damage (double-strand breaks), one must identify the number of pairs of sites activated which are separated by the requisite spacing of (2 nm and to distinguish these from unwanted pairs of sites that may be activated at different separation distances. Starting from a knowledge of the equilibrium slowing down electron spectrum in the material, a simplified approach is used to determine the yields of scintillation photons and paired events and their relationship to biological effectiveness. As may be expected, the results show that the combination from the paired events is very small compared to the normal scintillation yield but is of the same order as the ratio of double to single strand breaks for electron irradiation of mammalian cells cells. Both the theory and preliminary experimental investigation with a semi-infinite disc of plastic phosphor, 20 µm thick, reveals that the method is potentially promising but that more detailed study is required for optimisation of the fluor concentration and on the process for extraction of the desired signal from the practical device. Validation of the instrumental response function could be made by direct comparison with effect cross section data available for various damage end-points in mammalian cells. Radiation Protection Dosimetry Watt D.E. aut Alkharam A.S. aut Radiation Protection Dosimetry Oxford University Press 61/1-3(1995-08-01), 211-214 0144-8420 61:1-3<211 1995 61 rpd https://doi.org/10.1093/oxfordjournals.rpd.a082785 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.rpd.a082785 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Watt D.E. aut NATIONALLICENCE 700 1- Alkharam A.S. aut NATIONALLICENCE 773 0- Radiation Protection Dosimetry Oxford University Press 61/1-3(1995-08-01), 211-214 0144-8420 61:1-3<211 1995 61 rpd Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford