Since the simulation has only two rows of "atoms", there are only two reflected waves interfering. The applet shows the relative phase of the incident and reflected waves. Users can vary the interatomic spacing d, the wavelength l, and the grazing angle q. Only angles between 5 deg and 50 deg are permitted. Clicking on the "Details" button brings up a meter that shows the intensity of the combined waves. Since only two waves are combined, the intensity varies smoothly from a maximum at the angles satisfying Bragg's Law:
2dsinq = ml (m=1,2,3...)
Complete the following tables using the given values for each parameter. In each case, calculate the value of m from the values for d, l, and q.
For some combinations of d and l in the table above, there is more than one angle that satisfies Bragg's Law. Identify these case by determining the other angle(s) that work and calculate the corresponding value of m in each case. List your answers in the table below. Note: The number of rows in the table is not equal to the number of cases.