Evaluation of RQR beam quality at SSDL Jakarta Indonesia

Calibration services for radiodiagnostic X ray beam quality based on IAEA TRS457 guidance are being prepared by Secondary Standard Dosimetry Laboratory Jakarta, Indonesia. The RQR beam quality measurement has been completed, and most radiodiagnostic facility using general X ray equipment is our priority. Study of the characteristics of X ray spectra using XCOMP5R and Monte Carlo have also been undertaken for selected energy of the SSDL's X ray machine to evaluate the effective energy of Xray spectra. The measurements are done using Farmer type chamber NE2571 and Keithley Electrometer. The HVL measurements were undertaken based on IAEA TRS457 configuration; the additional filters are located 50cm from the source while detector is positioned at 100cm. All spectra of RQR beam quality were evaluated by using XCOMP5R. The RQR2, RQR5 and RQR10 spectra were evaluated using BEAMnrc monte carlo code. The X ray spectrum, effective energy and FWHM from XCOMP5R are compared with BEAMnrc. FWHM of each spectrum was calculated using correlation between standard deviation (δ) and FWHM with Gaussian distribution as the basis of calculation. The following equation is used FWHM= 2√2In(2) δ. Peaks of Spectrum of X ray characteristic appear for tube voltage above 70kV. In order to have Gaussian distribution the peak need to be removed since it will affect the relationship between standard deviation and FWHM