By: Evan A. Killilea Spring Seminar

Outline Nuclear Batteries Initial activity per unit mass Calculated activity in Curies(Ci) for 1 gram of pure Tritium Initial power produced per unit mass Calculated mass of pure Tritium necessary to produce initial power of 1 nW from decay Power is time dependent Comparing energy produced in first year to the energy produced 5 years later

Nuclear Batteries Generates electricity by the decay of a radioactive isotope Betavoltaics Emitting beta particles to generate electricity Non-thermal conversion process Tritium symbol T 2 or 3 H 2 atomic mass of u STP containing one proton and two neutrons years Decay energy MeV Extremely long life and high energy density

Activity Decay rate Radioactive Decay Equation A=A o e -λt A= current amount of radioactivity A o = initial amount of radioactivity λ =Decay constant - represents the average number of decays occurring per unit time = ln(2)/T 1/2

Number of Radioactive Nuclei Radioactive Decay Equation N=N o e -λt N= current number of radioactive nuclei N o = Initial of radioactive nuclei λ =Decay constant - represents the average number of decays occurring per unit time = ln(2)/T 1/2

Initial Activity A o α N o Initial amount of radioactivity α initial number of radioactive nuclei A o = initial amount of decay rate N o = Initial of radioactive nuclei λ =Decay constant - A o = λ N o

Initial Activity per Unit Mass

Tritium

Initial Power

Power Time Dependent

Conclusion

References K. Heyde, Basic Ideas and Concepts in Nuclear Physics, (IOP, Bristol, 1994). K. S. Krane, Introductory Nuclear Physics, (Wiley, New York, 1988). D. Lal and H. Suess, “The Radioactivity of t he Atmosphere and Hydrosphere,” Ann.Rev. Nucl. Sci. 18, 407 (1968).

Questions??