1. Modern Physics (PC300) Class #10: 1)Experimental basis for the Introduction of Quantum Theory a) Photoelectric Effect b) X-Ray Production c) Charge/mass of an electron d) Blackbody Radiation Ultraviolet Catastrophe Stefan-Boltzmann Law Wien’s Displacement Law 2) Gamma Rays…the ultimate photon How do gamma particles get detected… how do they interact with matter?

2. Quantum Homework Questions Blackbody and gamma spectroscopy questions. Also some from Thornton and Rex– Due Wednesday "Yeah, well I got mine first

3. Experimental basis for the introduction of a quantum theory. Photoelectric Effect – Almost done X-Ray Production Charge/mass of an electron Blackbody Radiation Stefan-Boltzmann law Wien’s Displacement Law Ultraviolet Catastrophe Review what we know about how gamma particles are absorbed by matter. Photoelectric effect Compton Scattering Pair Production

5. Ultraviolet Catastrophe Classical Physics – Rayleigh-Jeans Law

6. 1900 - Planck’s Law Unusual (Crick-Watson) type approach: -> Equation that fits data -> Make it work -> Could not justify finding 1918 Planck - Nobel Prize

7. How do we detect gamma rays?

24. Review: What is each peak? Why are they there? Calculate the location of the Compton edges and backscattering!