Comparison of national air kerma standards for ISO 4037 narrow spectrum series in the range 30 kV to 300 kV

Abstract

(b) , D. Butler (c) , I. Csete (d) , F. Gabris (e) , A. Hakanen (f) , J.-H. Lee (g) , M. Palmer (h) , N. Saito (i) and W. de Vries (j)

Comparison of air kerma standards for medium-energy x-radiation between the MKEH and the IAEA

“…The comparison results, R, for the selected beam qualities are the mean of the IAEA/MKEH ratios in the final column of Tables 4 and 5 for the two transfer chambers. It is interesting to note that these ratios are close to unity despite the fact that the results for the MKEH and the PTB (where the IAEA reference chamber was calibrated) in the EURAMET.RI(I)-S3 have a systematic difference as seen in column 8 of Table 8 showing the PTB/MKEH ratio R K taken from [3]. Normalizing the present results for IAEA/MKEH to the results for PTB/MKEH obtained in the EURAMET.RI(I)-S3 comparison would give the results R/R K for IAEA/PTB shown in the last two columns of the table.…”

“…Details of the MKEH primary standard free-air chamber for air kerma and its uncertainty are given in [3]. For the calibration of the transfer chambers the secondary standard chamber, type ND 1001 (#7807) was used, having a volume of 22 cm 3 and diameter39 mm.…”

“…EURAMET.RI(I)-S3.1 -Final Report dated 2012-06-13 comparison reference values, together with their combined uncertainties. These latter ratios, the resulting differences D for the IAEA from the EURAMET.RI-S3 comparison reference values [3] and the associated expanded uncertainties U D are listed in Table 9, which therefore shows the degrees of equivalence (D,U D ). It should be noted that the degrees of equivalence for the EURAMET.RI-S3 participants were established using the results for the smallest transfer chamber from the three transfer chambers used.…”

“…The relevant IAEA secondary standard ionization chambers are traceable to the Physikalisch-Technische Bundesanstalt (PTB), Germany in terms of air kerma and ambient dose equivalent. The comparison partner MKEH has a primary standard for air kerma and published degrees of equivalence (DoE) in the KCDB of the CIPM MRA based on the EURAMET.RI-S3 comparison results [3]. The ambient and personal dose equivalent quantities are derived by application of conversion coefficients published in ISO 4037 Part 3, similar to the PTB practice.…”

Establishment of ISO 4037‐1 X‐ray narrow‐spectrum series

“…The ISO 4037 narrow‐spectrum series X‐ray qualities are mainly used to calibrate radiation protection detectors of very large dimensions. Existing key comparison for air kerma for the ISO 4037 narrow‐spectrum series that cover the range from 30 to 300 kV is not direct comparison, such as BIPM.RI(I)‐K2 and ‐K3, but indirect comparison, such as EUROMET.RI(I)‐S3 whose results are available [3–5].…”