DEVELOPMENT OF THE DOSIMETRIC STANDARDS BASE

The article deals with the development of the reference means of support and metrological insurance required for  metrological  verification  and  calibration  of  beta  and  gamma  radiation  dosimeters.  The  latter  are  extremely  necessary  for dosimetric measurements of radiation characteristics in the field of radiation safety, radiation diagnosis and therapy. In addition to traditional  requirements and  issues related to  the design, development and use of  these standards, there are considered a row of problems caused by radiation safety, during the metrological inspection and calibration of dosimeters, as well as while creating and operating  the  standards  themselves.  The  purpose  of  this  work  is  an  analysis  of  the  state  of  the  metrological  provision  of measurements of gamma radiation characteristics in the area of dosimetric measurements and the search for ways to improve the reference base.

The  issue  of  transmitting  the  size  of  the  measurement  unit  with  reference  ionization  chambers  in  the  process  of metrological  checking/calibration  of  dosimeters  at  the  UDD-Inter  facility  is  also  considered.  It  is  shown  that  metrological verification/calibration is allowed for devices that have been compensated energetically.  It is underlined that testing of standards and calibration devices  for dosimetric control should meet  two main  requirements, namely  the contribution of external scattered radiation to radiation from the source in the capsule must not exceed 5 % of the total power in the air; the power of the considered radiation  in  the air should be  inversely proportional to  the square of  the distance  from  the center of  the  ionization source to  the detector center within deviations ± 5 %.