7D10.21 HALF-LIFE ( Measurement)

7D10.10 Radioactive Materials

Demonstrate radioactive decay using ratemeter. Alpha, beta and gamma sources available. Device provided will differ from that in photograph.


Setup Requirements:. Ratemeter with sound will normally be provided.


Equations: N = No( e-lt )


Safety Issues: Exposure to radiation.Damage to GM tube.

7D10.21 Half-Life Measurement

Demonstrate radioactive decay and half-life audible ratemeter. Uses Cs> Ba isotope generator to provide isotope with short half-life (%7e 3 min). Basic version shown.


Setup Requirements: Radioactive sample prepared shortly before use. 

Equations: N(t) = N(0) (1/2)^( t/half-life) 

Safety Issues: Exposure to radiation. Allow to decay away during class. Return planchet and remaining radioactive liquid to Demo Room.  Damage to fragile GM tube.

7D10.50 Probability

Dice and coins available to discuss probability in relation to half-life and quantum mechanics.


Setup Requirements: Minimal

Equations: Probability equations 

Safety Issues: None 

7D10.60 Shielding

Demonstrate different amounts of shielding needed for different sources using ratemeter. Beta and gamma sources available. Alpha source may be available. Device provided will differ from device in photograph.


Setup Requirements: Use Ratemeter with sound. Alpha source may have to be borrowed from Advanced Lab.  Ask at least 1 working day ahead of time.

Equations: None 

Safety Issues: Exposure to radiation. Damage to GM tube

7D10.80 Cosmic Rays

Demonstrate that detector is responding to some type of radiation when all sources removed. The counter produces random bursts of noise as cosmic ray showers pass through. This detector can be used to provide audible response to sources. Ratemeter provided may not be one shown below.


Setup Requirements: New ratemeter instead of one in picture may be provided. Old one erratic.

Equations: None 

Safety Issues: High voltage to GM tube. Damage to tube.