Difference between revisions of "Forest Scintillators"

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;Scintillation
 
;Scintillation
; the process by which atoms or molecules of a material are given enough energy by an incident particle of radiation to "excite" the system where upon its relaxation to a lower energy state is accomplished through the emission of light.
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: the process by which atoms or molecules of a material are given enough energy by an incident particle of radiation to "excite" the system where upon its relaxation to a lower energy state is accomplished through the emission of light.
  
 
In general, most materials are capable of scintillating.
 
In general, most materials are capable of scintillating.
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This air can loose its energy via collisions instead of through the emmision of light.
 
This air can loose its energy via collisions instead of through the emmision of light.
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The situation for your average solid isn't much better
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:<math>t_{collision}^{solid} = 0.1 ns</math>
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An atom in a solid can collide with 10 other atoms before loosing energy by emmitting a photon.

Revision as of 17:30, 8 June 2008

Scintillation
the process by which atoms or molecules of a material are given enough energy by an incident particle of radiation to "excite" the system where upon its relaxation to a lower energy state is accomplished through the emission of light.

In general, most materials are capable of scintillating.

It takes about 10^{-9} s ( 1 ns) for an atom to de-excite by giving off light. Atoms can , however, loose there energy by colliding with other atoms. Atoms which collide on time scales less than 1 ns could loose their energy via the collision instead of through the emmission of light.


At standard temperature and pressure, air has a velocity of about

[math]v_{air}^{STP} = 500 m/s[/math]

and a mean free path (distance between collisions) of 0.3 nm

this means the time between air molecule collision is about

[math]t= \frac{0.3 nm}{500 m/s} = 15 \times 10^{-12} sec \lt \lt 1 ns[/math]

This air can loose its energy via collisions instead of through the emmision of light.

The situation for your average solid isn't much better

[math]t_{collision}^{solid} = 0.1 ns[/math]

An atom in a solid can collide with 10 other atoms before loosing energy by emmitting a photon.