Comparison of pencil-type ionization chamber calibration results and methods between dosimetry laboratories.
A comparison of calibration results and procedures in terms of air kerma length product, PKL, and air kerma, K, was conducted between eight dosimetry laboratories. A pencil-type ionization chamber (IC), generally used for computed tomography dose measurements, was calibrated according to three calibration methods, while its residual signal and other characteristics (sensitivity profile, active length) were assessed. The results showed that the "partial irradiation method" is the preferred method for the pencil-type IC calibration in terms of PKL and it could be applied by the calibration laboratories successfully. Most of the participating laboratories achieved high level of agreement (>99%) for both dosimetry quantities (PKL and K). Estimated relative standard uncertainties of comparison results vary among laboratories from 0.34% to 2.32% depending on the quantity, beam quality and calibration method applied. Detailed analysis of the assigned uncertainties have been presented and discussed.
Greek Atomic Energy Commission (IRCL/GAEC-EIM), P.O.Box 60092, Agia Paraskevi, 15310 Attiki, Greece. Electronic address: costas.hourdakis@eeae.gr.
Costas J
CJ
Hourdakis
Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany.
Ludwig
L
Büermann
Vinca Institute of Nuclear Science, Radiation and Environmental Protection Laboratory (VINCA), University of Belgrade, P.O. Box 522, 11001 Belgrade, Serbia.
Olivera
O
Ciraj-Bjelac
International Atomic Energy Agency, (IAEA) PO Box 100, 1400 Vienna, Austria.
Istvan
I
Csete
International Atomic Energy Agency, (IAEA) PO Box 100, 1400 Vienna, Austria.
Harry
H
Delis
International Atomic Energy Agency, (IAEA) PO Box 100, 1400 Vienna, Austria.
Igor
I
Gomola
Swedish Radiation Safety Authority (SSM), Solna strandväg 96, SE-171 16, Stockholm, Sweden.
Linda
L
Persson
National Radiation Protection Institute (SURO), Batroskova 28, 140 00 Prague 4, Czech Republic.
Leos
L
Novak
Metrology of Ionizing Radiation, National Center of Radiobiology and Radiation Protection (NCRRP), 3 St.Georgi Sofiiski st, 1606 Sofia, Bulgaria.
Ivailo
I
Petkov
Radiation and Nuclear Safety Authority (STUK), P.O.Box 14, Laippatie 4, FI-00881 Helsinki, Finland.
Paula
P
Toroi
D000388:Air; D002138:Calibration; D005060:Europe; D007391:International Cooperation; D007477:Ions; D007753:Laboratories / Q000592:standards*; D015233:Models, Statistical; D015588:Observer Variation; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*
D007477:Ions
Air kerma length product; CT dosimetry; CT pencil type ionization chambers; Calibration; Comparison