Những người quan tâm trong bức xạ cần phải có, sau khi đọc cuốn sách này, các kiến thức để thực hiện tính toán liều lượng và đánh giá kích thước và mức độ ô nhiễm phóng xạ có thể xảy ra. Để thực hiện các tính toán về phóng xạ, chúng tôi sẽ sử dụng các phương trình được trình bày trong Chương 3. Nếu bạn có thể sử dụng các phương trình đơn giản 3,1, 3,2 và 3,3, bạn có thể tham gia vào tất cả các loại dự toán. Người đọc được mời để thực hiện các. | In this chapter we would like to give you an opportunity to exercise your knowledge about radioactivity and radiation doses Chapter 14 Exercises Examples and Scenarios Those interested in radiation should have after reading this book the knowledge to undertake dose calculations and to judge the size and extent of possible radioactive pollution. In order to perform calculations about radioactivity we will use the equations presented in Chapter 3. If you can use the simple equations and you can embark on all kinds of estimates. The reader is invited to perform the exercises presented on the following pages. You can look at the answers and follow the explanations given but you should try first. Exercise 1. Carbon-14 and number of atoms for 1 Bq It was noted in Chapter 3 that the C-14 activity can be used to determine the age of artifacts. Two types of measuring techniques were discussed either to determine the number of disintegrations number of Bq in a sample or to calculate the total number of C-14 atoms in the sample. The latter method is far more sensitive because billion C-14 atoms are needed to give one Bq. The first exercise proves this. 2003 Taylor Francis 206 Radiation and Health The question is How many C14 atoms are in a radioactive source with an activity of 1 Bq The half-life for C-14 is 5 730 years. E Solution You can solve this question by starting with the equation for the activity . the number of disintegrations per second dN dt NẢ Here N is the number of atoms in the source the answer to our question . Furthermore dN dt 1 Bq. The disintegration constant X in sec-1 is according to equation in Chapter 3 given by Ẳ _ _ _ t1 2 _ 5730 365 24 60 60 As you can see the half-life which was given in years is transformed to seconds because the activity is given in Bq. It should now be easy to find that N 1 X billion atoms. 2003 Taylor Francis Exercises Examples and Scenarios 207 Exercise 2. Ra-226 and I-131 a The .
