Introduction: Due to its simplicity, fast response and high reliability, ion chamber detectors are one of the most suitable dosimetry instruments for X and gamma rays. The dosimeter    of photon beams, which used in radiotherapy centers, requires high accuracy and should pass requirements of IEC 60731 standards. About 80 percent of the IEC 60731 standard tests such as stabil...

introduction: delivering maximum dose to tumor and minimum dose to normal tissues is the most important goal in radiotherapy. according to icru, the maximum acceptable uncertainty in the delivered dose compared to the prescribed dose should be lower than 5%, and this is because of the relationship between absorbed dose, tumor control and normal tissue damage. absorbed dose accuracy is investiga...

Introduction Computed Tomography scans are a very important tool for diagnosis and assessment of response to treatment in the practice of medicine. Ionizing radiation in medical imaging is undoubtedly one of the most powerful diagnostic tools in medicine. Yet, as with all medical interventions, there are potential risks in addition to the clear potential benefits. Materials and Methods Two refe...

A tandem ionization chamber, developed at the Instituto de Pesquisas Energéticas e Nucleares (IPEN), for X radiation beams, radiotherapy level, was applied into a quality control program of the Calibration Laboratory of IPEN. This ionization chamber is composed by two ionization chambers, with a volume of 0.6 cm each one. Its inner plane-parallel electrodes and guard rings are made of different...

Background: The effectiveness and safety of brachytherapy treatment is mainly concerned with the calibration of sources and their traceability to internationally accepted Standards. Secondary Standard Dosimetry Laboratory (SSDL) does not offer calibration of ionization chambers with gamma-ray spectrum of high dose rate source 192Ir . This work has been carried out to calibrate the high dose rat...

A time-of-flight mass spectrometer (TOF-MS) developed in our laboratory at Isfahan University of Technology is described here. The TOF-MS instrument uses laser as the ionization source which provides an opportunity to investigate the ions formed in laser ablation or desorption. The TOF-MS has an ionization chamber containing an accelerator and an ion lens to focus the ions into a one meter line...