قياس عامل التراكم لأشعة كاما في مادة الحديد والألمنيوم كدروع متحركة باستخدام الكاشف ألوميضي

Abstract

In the present work , the gamma ray buildup factor has been Calculated for iron and aluminum as a fixed and moving shields with two velocities ( V1= 16 cm/sec ) and ( V2= 18 cm/sec ) for thicknesses ( 0.1 – 1 ) cm . by using the scintillation detector NaI(Tl) ( 2″ x 2″ ) and two radioactive sources Cs-137 & Co-60 .The effect of the shield movement , its thickness and the radioactive source energy on the buildup factor has been studied .It was found that the buildup factor for iron decreased with a moving shield , The buildup factor at (V1) velocity was less than that at (V2) velocity . while , the buildup factor increased for aluminum The buildup factor at (V2) velocity was greater than that at (V2) velocity . The buildup factor increased with the thickness of the shield for all studied cases . It was found that the buildup factor with Co-60 source was greater with Cs-137 source for all fixed and moving cases .