About how far do 5.5MeV alpha particles travel in (not heavy) water?

>>8807354
Is all probablistic. It could travel a long ways before interacting with anything

>>8807454
I hate you so goddam much.

>>8807472
I mean, your question is pretty vague.

Each time it passes by a water molecule, it loses energy. The complicated part is that it loses a different amount of energy depending on the scattering angle. So you need to find an average angle. Then you can see how many particles it hits before it loses all its momentum. The spacing of the water molecules tells you how far it goes basically.

Fortunately, you can do it using classical mechanics

>>8807454
its not a photon, alphas have discreet ranges in whatever medium they are travelling in.
the question is not vague at all, there is a finite answer (about 4 cm)

http://www.alpharubicon.com/basicnbc/article16radiological71.htm

http://s3.amazonaws.com/zanran_storage/www.maths.tcd.ie/ContentPages/383913277.pdf

http://www.maths.tcd.ie/~tkachev/alpha_particles.pdf

>>8807454
charged particles interact continuously electromagnetically, and then also collisionally. they aren't like gammas or neutrons that interact stochastically.
that's why charged particles have well defined. LET/RBE and range characteristics, and gammas dont

>>8807777
>>8807780
www.med.harvard.edu/jpnm/physics/nmltd/radprin/sect7/7.2/7_2.2.html

>>8807354
I just calculated that of 5.0 MeV in 20°C
It's 65.000 km/s

>>8807802
>asks for range
>gives some velocity figure
>as if velocity is ever constant, and the alpha isnt continuously decelerating

>>8807777
I never said anything about photons.

This is basically a Rutherford scattering problem.

>>8808017
Alphas have finite maximum ranges in any medium. Their interactions are not stochastic. There are very simple formulas for determining the maximum range in water.

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http://www.alpharubicon.com/basicnbc/article16radiological71.htm