I'm looking for some experimental evidence of quantum wave packets spread to propose to my students. I notice that a huge attention is devoted in books to the theoretical frame, while almost nothing is said about real experiments with electrons or other particles. Still we have quantitative predictions (mainly, on variance dependence on time) and I'm sure they have been tested. Actually the complex experiments on packet revival do the job, but I'm looking for conceptually simpler (possibly historical) cases.
Can you help me?