absorptions coefficient

[Kahsi]

Hi.

I have done this lab where I had a GM-detector and some leadboards. I was mesuring how many decay it detected and tryed 0 - 6 leadboards to see the difference.

We know that

I = I_0e^{-x\mu}

How can I find out the value of \mu in the graph (http://home.tiscali.se/21355861/bilder/absorption.GIF) (the linear absorption coefficient)?

I = number of decays?

I just need some hints.

Thank you.

[Kahsi]

I have done this,

I = I_0e^{-x\mu}
\frac{I}{I_0} =e^{-x\mu}
\ln\left(\frac{I}{I_0}\right) =-x\mu
\ln\left I =-x\mu + \ln I_0

Then if we take ln(numbers of decays) we would have this graph:
y = ax + b

a = \mu = y'

then I just have to do a linear regression and get the value of \mu.

Then \mu = 0,205. Does this seem correct?

[OlderDan]

I have done this,

I = I_0e^{-x\mu}
\frac{I}{I_0} =e^{-x\mu}
\ln\left(\frac{I}{I_0}\right) =-x\mu
\ln\left I =-x\mu + \ln I_0

Then if we take ln(numbers of decays) we would have this graph:
y = ax + b

a = \mu = y'

then I just have to do a linear regression and get the value of \mu.

Then \mu = 0,205. Does this seem correct?

Except for dropping a minus sign when relating your slope parameter (a) to \mu, everything looks good. Your graph should be linear with negative slope giving you a positive value for \mu.