انت هنا الان : شبكة جامعة بابل > موقع الكلية > نظام التعليم الالكتروني > مشاهدة المحاضرة

Activity radiation

Share |
الكلية كلية التربية للعلوم الصرفة     القسم قسم الفيزياء     المرحلة 7
أستاذ المادة بهاء حسين صالح ربيع الحسيني       29/03/2017 07:55:42
Activity
It is easy to see that a radionuclide with a short half-life will undergo radioactive decay at a very rapid rate, while a radionuclide with a long half-life will have a much smaller rate of decay. If you have a sample of one billion (109) sodium-25 atoms, you would expect about 11 million of these to decay during the next second. On the other hand, if you have sample of one billion tritium atoms, you would expect only 1 or 2 of these atoms to decay during the next second.
For convenience, radioactivity is measured in units of activity, or the number of decays taking place each second. The traditional unit of activity is the curie, named after Marie and Pierre Curie (the discoverers of radium). One curie, abbreviated Ci, is equal to 3.7 x 1010 disintegrations per second (dps). Since this is an extremely large number of decays per second, the activity is usually expressed in smaller multiples:
1 x 10-6 Ci = 1 microcurie, or
1 x 10-3 Ci = 1 millicurie.
The International System of Units (Système International, or SI) utilizes a different unit of activity, the becquerel. One becquerel, or Bq, is equal to one dps. Since this amount of activity is inconveniently low, the SI units are normally expressed in large multiples of Bq (megabecquerel or gigabecquerel). The SI and traditional units are summarized


المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
download lecture file topic