We mounted a NaCl crystal on the crystal post of the machine, set the machine to 30 kV and .05 Amps then used the GM tube to collect the counts. We took the measurements for 10 seconds and did three trials for each degree. We moved the GM tube by one degree starting at 20° and ending at 90°.
Our data resembles the data provided in the manual but heights of the peak are smaller in our data. This could be because the beam is not running at full strength due to age or another problem we have not identified yet.
To measure the wavelength we used Bragg's law. Bragg's law states nλ=2dsinθ, where n is an integer, λ is wavelength of the x ray, d is the distance between atoms in the crystal and θ is the angle. For this experiment n=1. The distance for a NaCl crystal is .282 nm. The two peaks are at 31° and 58°.The wavelengths at the two peaks are .29 nm and .49 nm respectively. Both of these wavelengths are consistent for x-rays.
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