SUCCESSIVE GAMMA-RAY IRRADIATION AND CORRESPONDING POST-IRRADIATION ANNEALING OF pMOS DOSIMETERS

摘要

Размотрена je могуhност примене pMOS дозиметара за поновно меренъе дозе гама зраченъа. Ови дозиметри су озрачивани до дозе 35 Су, потом опоравлъани на собноj и повишеноj температури и поново озрачивани до исте дозе. Праhене су промене напона прага током ових процеса и показано jе да нъихова поновна примена зависи од напона на геjту током зраченъа. За напон на геjту од 5 V pMOS дозиметри се могу ефикасно применити за поновно меренье дозе после опоравка. Такоъе, pMOS дозиметри чиjа jе поларизациjа на геjту 2.5 V могу се применити за поновно меренье дозе уз претходну калибрациjу. За поновну примену pMOS дозиметара потребно jе извршити опоравак тако да фединг буде веhи од 50%.%The paper investigates a possibility of pMOS dosimeter re-use for the measurement of gamma-ray irradiation. The dosimeters were irradiated to the dose of 35 Gy, annealed at room and elevated temperatures, after which they were irradiated again to the same dose value. Changes in the threshold voltage shift during those processes were followed, and it was shown that their re-use depends on a gate polarization during irradiation. For the gate polarization of 5 V during irradiation the pMOS dosimeters can be re-used for measurements of the irradiation dose after annealing without prior calibration. The pMOS dosimeters with the gate polarization during irradiation of 2.5 V can also be re-used for irradiation dose measurements but they require calibration. It is shown that for their re-use it is necessary to anneal the pMOS dosimeter so that the fading is higher than 50%.