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

[nykon]

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

 

[zhermes]

Then you should multiple by the number of sr

 

[nykon]

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

 

[zhermes]

Yeah, I think that looks great!

 

[pmacias]

,

Thank you for your question. Converting proton flux measurements from 1/(cm^2 s sr) to 1/(cm^2 s) is a common conversion in the field of particle physics. This conversion involves taking into account the solid angle subtended by the detector, which is represented by the "sr" unit in your measurement. To convert from 1/(cm^2 s sr) to 1/(cm^2 s), you will need to divide your original measurement by the solid angle in steradians (sr). The solid angle can be calculated using the formula Ω = A/R^2, where A is the area of the detector and R is the distance from the source to the detector. Once you have calculated the solid angle, you can then divide your original measurement by this value to obtain the desired units of 1/(cm^2 s). I hope this helps. If you need further assistance, please don't hesitate to ask.