Models for dead time correction x and gama ray detectors

Electronic devices are used to detection of radiation due to x or gamma rays. The dead time of counting systems is based on time limitations of these electronic devices that used at counting systems. This work was done to determine of a analytic equation for the dead time and of counting losses at low and high counting rates and at pile up peak counting rates and at pile up pulse reject counting rates and of counting losses due to minimum resolving time of amplifier according as this dead time and to correct these counting losses.In this work contain to determination of proper peaking time of counting system and to a dead time correction model for observed spectrum at low counting rates and to a model for correction of counting rates at medium and high counting rates and to correction of counting rates pile up peak and pile up pulse reject and to correction of counting rate losses result from peaking time of amplifier and simulation programs.Consequently, proper peaking time, critical resolving time and characteristic resolving time of the amplifier was founded as 3.84, 3.66 and 3.73 ?s for first part, respectively. Also, a new model for low count rates was proposed in second part. In addition to these, new proposed theoretical models at third and fourth parts of working compared with results from coded simulations programs. A pretty good agreement is obtained between theoretical models and simulation programs.