Results 131 to 140 of about 2,824 (166)

Air-kerma cavity standards

Metrologia, 2009
This paper reviews the current status of air-kerma cavity standards for gamma rays from 60Co, 137Cs and 192Ir sources. It describes the basic principles and the theories to determine the air-kerma rate from the ionization current of graphite-walled cavity ionization chambers. A typical design of a cavity chamber is shown and described.
L Büermann, D T Burns
openaire   +1 more source

Seasonal variation of air kerma rate in Sicily

Journal of Environmental Radioactivity, 2008
Thermoluminescence dosimetry has been used to measure air kerma in 29 sites in Sicily. Four three month measurement campaigns have been carried out in order to assess seasonal variations. Average annual values between 20 and 90 nGy h(-1), after cosmic background subtraction, are reported.
BASILE, Salvatore, BRAI, Maria, MARRALE, Maurizio, RIZZO, Salvatore   +3 more
openaire   +3 more sources

103Pd loaded cartridge air kerma strength verification

Medical Dosimetry, 1999
Using radioactive 125I or 103Pd seeds in large number to treat prostate cancer has become popular. This procedure's popularity translates to increased physicist and dosimetrist workloads with regard to performing source strength assays. In addition, radiation exposure to the physicists' and dosimetrists' hands as a result of source handling has ...
D E, Mellenberg, E C, Pennington
openaire   +2 more sources

Calibration and features of air-kerma length product meters

Radiation Protection Dosimetry, 2012
Pencil-type air-kerma length product meters are generally used for quality control and radiation exposure measurements in computed tomography. To ensure reliable results, these meters should be calibrated so that measurements are traceable to international standards.
K, Merimaa, M, Tapiovaara, A, Kosunen, P, Toroi   +3 more
openaire   +2 more sources

Changes to the VNIIM air kerma primary standard

Metrologia, 2007
The result of extensive Monte Carlo calculations and a re-evaluation of the volume of the primary standard has led to an increase in the determination of air kerma at the VNIIM by 9.6 ? 10?3. The contributions to this change are summarized in this short note to announce that the VNIIM primary standard changed with effect from 1 November 2007.
I A Kharitonov, A V Oborin, A Y Villevalde   +2 more
openaire   +1 more source

Inherent uncertainty of air kerma

Metrologia, 2013
Air kerma is defined in air, the constituents and the amounts of which are determined experimentally with some uncertainties. The inherent uncertainty of air kerma in a photon beam stemming from the uncertainties of atomic weights and composition data in air was evaluated as a function of photon energy.
openaire   +1 more source

Development and characterization of air kerma cavity standard

Measurement: Journal of the International Measurement Confederation, 2019
Abstract Ionization chambers are the most common detectors for precise measurements such as these required in radiation protection and radiotherapy. This paper presents the design, development and characterization of a new graphite-walled cavity ionization chamber used as a primary standard for air kerma rate for 137Cs and 60Co gamma radiation of the
M.M. Szymko, L. Michalik, A.B. Knyziak, A.W. Wójtowicz   +3 more
exaly   +2 more sources

Comparison of air kerma area product and air kerma meter calibrations for X-ray radiation qualities used in diagnostic radiology

Metrologia, 2015
The EURAMET #1177 project, identified as EURAMET RI(I) - S9 comparison, was the first EURAMET wide scale supplementary comparison in the field of diagnostic radiology for air kerma area product, PKA, and air kerma, K. It was conducted with the goal of testing the measurement and calibration capabilities for PKA and K, as well as of ...
C J Hourdakis, I Csete, J Daures, H Jarvinen, L-C Mihailescu, V Sochor, L Novak, M Pedersen, A Kosunen, P Toroi, M Denoziere, L Büermann, A Megzifene, G Einarsson, P Ferrari, J dePooter, H Bjerke, M Brodecki, J Cardoso, S Bercea, O Ciraj-Bjelac, J Compel, D Glavič-Cindro, M Ginjaume, L Persson, J -E Grindborg   +25 more
openaire   +3 more sources

Determining air kerma from pixel values in digital mammography

Physics in Medicine and Biology, 2009
The pixels in digital detectors used in x-ray imaging can be considered as small dose meters. In mammography, the image detector area is commonly only partly covered by tissue and the incident air kerma could be monitored by using pixel values from the detector elements in the unattenuated primary beam area.
P, Toroi, M T, Nieminen, P, Tenkanen-Rautakoski, M, Varjonen   +3 more
openaire   +2 more sources

Air kerma based dosimetry calibration for the Leksell Gamma Knife

Medical Physics, 2009
No accepted official protocol exists for the dosimetry of the Leksell Gamma Knife® (GK) stereotactic radiosurgery device. Establishment of a dosimetry protocol has been complicated by the unique partial‐hemisphere arrangement of 201 individual beams simultaneously focused on the treatment volume and by the rigid geometry of the GK unit itself.
Sheridan Griffin, Meltsner, Larry A, DeWerd   +1 more
openaire   +2 more sources