Question

a Geiger ionization chamber contains 60 cubic cm of air and records 500 mR/min. calculate (a). the current produce by the chamber (b). the total number of ion pairs produced per hour of exposure.
please answer, thank you!,

Answer 1

V=60 cm³
500 mR/min= 500•10⁻³/60 = 8.33•10⁻³ R/s,
the charge in 1 cm³ is
q= 8.33•10⁻³•3.33•10⁻¹º =2.78•10⁻¹² C
in chamber
Q=2.78•10⁻¹²•60 =1.67•10⁻¹º C
I=Q/t= 1.67•10⁻¹º A
1 R produces 2.08 •10⁹ pairs of ions in 1 cm³
N= 8.33•10⁻³•2.08 •10⁹ = 1.73•10⁷ pairs per second