Radiography

Radiography is a technique that produces images on photographic film using a radiation source. The basic principle is similar to traditional photography; however, radiation is used in place of visible light. Ionizing radiation exposes the undeveloped film, and after processing, the film reveals the location and intensity of the radiation source as well as the shape and structure of any objects positioned between the source and the film.

Objective   

To investigate the intensity of beta particles on photographic film.

Procedure

1. Place film with lens side up on a flat surface.

2. Uncoil a paper clip and place it in the center of the film.

3. Next, place the beta source over the clip, so that the quarter inch window is directly over the object. Carefully tape the objects to the film.

4. Allow the film to absorb the radiation overnight.

5. Remove the objects from the film.

6. Turn select lever on film holder to "load" and load film.

7. Next, turn select lever on film holder to "process" and remove film.

8. Allow 60 seconds for the development of the film before removing the picture.

9. Repeat the same procedures, but move the source 1 cm from the clip and film.

10. For a control, repeat steps 1-8 without using a paper clip.

Questions:

1. Why is it necessary to have a control?

2. Compare the paper clip images with the control image.

3. Why was there a difference in intensity?

4. Would gamma radiation produce an image of the paper clip? Explain.

Optional: 

1. Try different types of objects, such as a plastic comb, rubber band, or string.

2. Determine the maximum distances and lengths of exposure time needed to produce images of the above objects.