Origin of Cosmic Rays: Intensity Explained

[logearav]

we all know the cosmic rays comes from outer surface of the Earth from higher altitudes and enter the Earth's atmosphere in all directions. but experimental studies have revealed that intensity of cosmic rays increases with altitude and reaches a maximum at about 20 km above Earth surface and above that altitude , the intensity decreases. cosmic rays, being high energetic, comes from outer surface but its intensity is less at higher altitudes above 20 km. what is the reason for this?

 

[NobodySpecial]

Most of the cosmic rays you detect eg. as noise in CCDs are muons created in the atmosphere when higher energy particles form space hit atoms

At low altitudes these secondary muons will have been absorbed by hitting other atoms, at very high altitudes there aren't enough atmospheric atoms to be hit by high energy particles and so fewer muons are generated.

 

[Chronos]

Any notion that cosmic rays originate more from Earth than anywhere else seriously conflicts with observational evidence.

 

[logearav]

thanks nobody special for your explanation

 

[NobodySpecial]

Just to make Chronos' point clear.
Primary cosmic rays originate in space. When they enter the atmosphere they collide with atoms in the atmosphere and make a whole shower of secondary cosmic rays, it's these secondary rays that you mostly detect and have a characteristic height profile.

 

[physalpha]

That's the area of accumulated energy problem.
Actually the cosmic ray intensity is high in the space.
But accumulated amount of the ionized particle is high around ~ 20km altitude.

--- high altitude area very low moleclular concentration, collison possiblity very low
.
.
--- middle altitude area low molecular concentraiton , collision probablity is high
.........(high amount of ionic atoms exist)
.
--- low altitude area very high molecular concentraion, low amount cosmic ray reached from the space
.
That's the amount of accumulated high energy particle problem.