I calculating the number of Electrons? (Current/Electron Density/Velocity)

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To calculate the number of protons in the beam at Fermilab's Tevatron, one must understand the relationship between current, electron density, and velocity. The current of 11.17 mA can be related to the number of protons using the equation for current density, which involves the cross-sectional area, drift velocity, and charge of the protons. The user expresses confusion over how to derive the necessary values, particularly the cross-sectional area, from the given information. Additionally, there is a query about the significance of current density in this context. Understanding these concepts is crucial for solving the problem effectively.
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Homework Statement




How many protons are in the beam traveling at the speed of light in the Tevatron at Fermilab, which is carrying 11.17 mA of current around the 6.3-km circumference of the main Tevatron ring?

Homework Equations



Not sure...



The Attempt at a Solution



I don't know how to calculate the the protons (electrons). I tried multiple different things but al the equations I have use the Cross Sectional area value (A) which can't be found from the given information.

I tried manipulating such equations as

current density = (number of electrons)(e)(drift velocity)

and other similar equations but the all contain some form of the value of A?

Please help :(
 
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What is current?
 


voko said:
What is current?

and how do you find J {current density} from I {current} and a circumference?
 


Liquidxlax said:
and how do you find J {current density} from I {current} and a circumference?

What is the significance of current density here?
 


Ok got it! Thank You!
 
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