Pre-Lab Questions to Lab 7 - X-Rays and Atomic Structure

1. Download and print out the Table of Binding Energies and bring it to class and to the lab. This table is needed to answer the questions below, as well as for work during the laboratory period

2. In Experiment 3 we used X-rays generated in a tube with a copper anode. Other types of X-ray tubes have a cobalt anode. Use the table of binding energies to calculate the wavelengths of cobalt K$\alpha$1 and K$\alpha$2 X-rays. (Note: while in optical spectroscopy it is common to use wavelengths or inverse wavelengths (so-called wave numbers) to describe the observed photons, in X-ray and $\gamma$-ray spectroscopy it became convention to describe photons in terms of their energy). Show your work.
   Another note: This lab requires frequent look-up of binding energies; therefore print out the table of binding energies and bring it with you to the lab.

3. The spectra that we will analyze during this experiment have been recorded with a proportional counter. Do you expect to see such features as the K$\alpha$1 and K$\alpha$2 lines in the X-ray spectrum? Explain why or why not.

4. Suppose you are irradiating a five-cent coin (a nickel) with a 100 keV gamma ray to produce fluoresence radiation. According to the Department of Treasury web site the nickel "is composed of a homogeneous alloy containing 75 percent copper and 25 percent nickel." What is the energy of the fluoresence radiation you will most likely measure from the irradiated nickel?

5. Examine the periodic table of the elements on the inside-cover of the lab manual. It has two mystery entries in the upper right-hand corner of each element. The meaning of these numbers remain for you to be discovered, but once you know what they are, the work during the lab will be greatly expedited. Here is a hint: combine the numbers you find in the Table of Binding Energies in a meaningful way!

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