Freehand experiment Diffraction

From the rim to the diffraction pattern: a disorder-order transition

Experiment series as a freehand test.

With the film set for freehand experiments for diffraction, the transition from the wreath to the diffraction pattern of a cross grating can be observed. One looks at small, bright lights in a dark environment with one eye and holds the film directly in front of the eye. The film structure is seen through while looking at the lamp. A prerequisite for a clear transition from one appearance to the other is a sufficiently large distance between the lamp and the observer; 5 m and more are recommended here.

This classic structure of a freehand experiment for diffraction is used in a series of experiments in which there are 11 slides on each slide. A large number of the same elements are increasingly arranged on them in the places of a cross grid. A statistical distribution of the elements, combined with a certain disorder (slide 1), gradually recedes in favor of a regular arrangement in a cross grid (slide 11). The elements themselves are - insofar as the film material allows - transparent on a black (opaque) background and have the form of circles, tilted squares or lying drops.

If you slide the film from right to left in front of your eyes in a darkened room, the gradual transition from disorder to order in the pattern of the transparent film changes the view of the lamp from the rim (slide 1) to the diffraction pattern (slide 11). In the transition from slide 1 to slide 11, the diffraction pattern appears with increasing contrast in the appearance of the ring until the pure diffraction pattern of the cross grating is reached in the last station.

Freehand experiments diffraction set of 3 Foil strips with 11 "slides" per strip, each consisting of one strip: circle, tilted square, drop. A 26-page, illustrated instruction manual is included.

Use: Physics (optics) 12th grade
Dimensions: 29.5 x 9 cm

Additionally required: A halogen lamp with a small filament.