1. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 1 Radioactivity

2. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 2 Radioactivity

3. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 3 Radioactivity Natural decay series Other 2? HW 10

4. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 4 Radioactivity

5. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 5 Radioactivity

6. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 6 Radioactivity ≡ decay constant. Compare to human life time!!!

7. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 7 Show that the mean lifetime. N is difficult to measure. Instead, measure  N ≡ number of decays between t and t +  t :  t <<  (i.e. << t 1/2 ) If  t <<  (i.e. << t 1/2 ) then show that and thus defining the activity A(t ): RadioactivitySlope=?!!!!!!!!!! Be careful.

8. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 8 Radioactivity HW 11 Krane Problem 6.1 Activity measured in units of becquerel (Bq) = 1 decay/s. 1 curie (Ci) = 3.7 x 10 10 Bq. Activity is not dose!!!!!

9. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 9 Radioactivity Exponential decay of species 1 and exponential growth of species 2. Isotope 1 (initial number N 0 ) decays into “stable” isotope 2.

10. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 10 Radioactivity If parent nucleus decays by two modes: Derive.

11. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 11 Radioactivity If radioactive species 1 is produced in a reactor or accelerator with rate R. ProductionDecay Show that and thus secular equilibrium almost linear HW 12

12. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 12 Radioactivity How long should we irradiate? Activity per cost?

13. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 13 Radioactivity If species 2 is radioactive. Possible also that species 3 is radioactive. 1  2  3  4 ….. until we reach a stable isotope. But for now let us consider species 3 to be stable. For the parent nucleus assume that N 1 (t=0)=N 0. For the daughters assume that N 2 (t=0) = N 3 (t=0) = 0. Verify the following: What if 2 = 0? What if 1 is very small? N 1 ( t ) = ?

14. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 14 Secular equilibrium 1 is very small ( 1 << 2 ) ► For large time t, A 2  N 0 1 which is the limiting value for secular equilibrium. Constant activity ► production = decay. Radioactivity ▼ What if t ½ for 132 Te were 78d?

15. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 15 Radioactivity Transient equilibrium If 1 is smaller than 2 ( 1 < 2 ), show that

16. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 16 Radioactivity As t increases, but the activities themselves are not constant. 230 Th decays, in effect, with the decay constant of 234 U. Parallel !?

17. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 17 Radioactivity Discuss the case when 1 is larger than 2 ( 1 > 2 ).

18. Nuclear Physics, JU, Second Semester, 2010-2011 (Saed Dababneh). 18 Radioactivity In general, 1  2  3  4 ….. until we reach a stable isotope. If N 0 of type 1 and N 2 (t=0) = N 3 (t=0) = … = 0 ► Bateman equations. Exclude the term ( k - k ).