IMS SCIENCE                                                          Name(s): ________________

Alpha, Beta, Gamma Rays Lab                                Period: ___ Date: _____ Score: _____/ 20
Academic Standards:  3.1, 3.2., 3.4.
The purpose of this lab is to investigate the detection, shielding, and storage considerations needed when handling radioactive sources.

The source will be the mantels we worked with before.  Source distance: The distances of source from Geiger counter in centimeters.

Shielding Type: determine which shielding materials seem to provide the “best” overall shielding for the given source, using the following materials.

Net Count Rate: This is the difference between the background rate and source rate and should be about 40 to 50 counts per minute at a certain distance from the Geiger counter. This would be the counts due to the source.
 

Source rate         : _______ (c/p/min) Source distance: ____ c.m.initial

 

Subtract the    Background rate: _______ (c/p/min)   (Determined as a class)

                     ----------------------------------------------------

                       Net Count Rate :   _______ (c/p/min) 

(The difference between the source rate and the background rate)

DO NOT CHANGE SOURCE DISTANCE FROM THE GEIGER COUNTER ONCE YOU START ACTIVITY.

                              Net Count Rate      Is It A ___ Ray               RATE SHIELDING   Name Particle

Materials:                 (c/p/min)            Alpha/Beta/Gamma    Good/Better/Best      Stopped (A/B/G)

1. Index Card:

 

 

 

 

2. Thin Plastic

 

 

 

 

3. thick Plastic

 

 

 

 

4. Aluminum

 

 

 

 

5. lead

 

 

 

 

6. Wood

 

 

 

 

7. other
 

 

 

 

 

Questions:
1.  What is the distance required to reduce the Net count rate to one-half its initial strength. 
Net count rate initial: ______(c/p/min)   / 2 should be    = ______  (c/p/min) at _____ c.m.
                                                                  It actually was = ______ (c/p/min)  at  _____cm.

2. Describe the relationship between distance and count rate? _______________________________

3. Describe the relationship between shield thickness and count rate? __________________________

4. Do different forms of radiation travel differently through the air?____________________________

5. How do you know if a shielding material has completely stopped a radiation type?_______________

6. What are the three* independent variables in this experiment? ___________  ___________   ____*