Question

15 Points) The following absorption data were taken using aluminum absorbers. a) Plot the data. What type of radiations does the results suggest? b) What are the energies of the radiations? c) What is the most likely isotope? Absor (em) ber Thickness Counts per Minute Absorber Thickness Counts per Minute (em) 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 1000 576 348 230 168 134 120 107 0.16 0.2 0.4 0.8 1.5 96 95 90 82 68 60 2.8 50

Answer 1

From the given absorption data using aluminium absorbers

a) Drawn below is the plot of counts per min versus absorber thickness

Plot 1200 1000 드 800 600 8 400 200 C/min 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.2 0.4 0.815 2 2.8 Absorber thickness (cm)

Type of radiation = beta radiation

These radiations can penetrate few milimetres of Al sheets but is stopped by thick sheets of same metal

b) energies range from low KeV to low MeV.

c) Most likely isotope is tritium which gives off beta particle.