How Do You Convert Proton Flux from 1/(cm^2 s sr) to 1/(cm^2 s)?

AI Thread Summary
To convert proton flux from 1/(cm^2 s sr) to 1/(cm^2 s), it is necessary to multiply by the solid angle in steradians (sr). The user calculated the solid angle based on a detector with an effective area of 1 cm^2 at a distance of 1 meter, resulting in a solid angle of approximately 9.92 x 10^-5 sr. This calculation involves determining the surface area of a sphere and the ratio of the detector's area to that surface area. The forum participants confirmed the calculation as accurate. Understanding the concept of solid angles is crucial for this conversion.
nykon
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Dear forum users,

I have a quite simple question. I have got a flux of protons measured in 1/(cm^2 s sr), I would like to have it in 1/(cm^2 s).


nykon
 
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Then you should multiple by the number of sr
 
zhermes said:
Then you should multiple by the number of sr

Yes, I have got problem with sr concept:p Let's say that the distance between source and the detector is 1m. My detector has effective area of 1 cm^2. So by how many sr I should multiply my flux?

My answer would be:

The area of the sphere with radius of 1m^2 is:

S = 40000 \pi [cm^2]

the effectiv area of the detector is D = 1cm^2, so:

\frac{D}{S} = \frac{1}{40 000 \pi} = \frac{1}{125600} = 7.9 \times 10^{-6}

So the soild angle of my detector should be:

θ_{D} = 4\pi \times 7.9 \times 10^{-6}[sr]

So finally:

θ_{D} = 9.92 \times 10^{-5} [sr]

Am I right?


nykon
 
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Yeah, I think that looks great!
 
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