Mass and Its Effect on Wavelength

The conclusions we can draw from the exploration with protons and neutrons are:

1. that protons and neutrons both exhibit wave behavior;
2. the charge on the particle does not appear to effect the interference pattern; and
3. perhaps due to their similar size and mass their interference patterns are the same.

We will need to investigate the effect of mass further however in order to confirm the third conclusion.

Use the Double Slit program to compare the interference patterns of electrons, pions and neutrons. These three particles differ widely in mass, so if we keep the other variables (energy and slit separation) constant we will be able to see if mass effects the interference pattern.

HINT: Use a slit separation of 0.5 nm and an energy of 200 eV for all three particles.

When you have compared the interference patterns of electrons, pions and neutrons answer the following questions:

• As the mass of the particle increases what happens to the distance between dark regions in the patterns?
• If we assume that E = hc/l as for light, what happens to the wavelength as mass increases?