Thread: Alpha radiation
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May16-11, 05:31 AM
P: 152
I agree with the bremsstrahlung...

beta plus produces positrons which can annihilate with electrons releasing photons

heres one source

heres another

and another...

"The slowing-down processes have the same effect on both β− and β+ particles. However, as antimatter, the positron (β+) cannot exist for long in the presence of matter. It soon combines with an atomic electron, with which it annihilates, the masses of both particles being replaced by electromagnetic energy. Usually this annihilation occurs after the positron has come to rest and formed a positronium atom, a bound but short-lived positron-electron system. In that case, the electromagnetic energy that is emitted from the annihilation takes the form of two 511-keV gamma rays that are emitted in opposite directions to conserve momentum. See also Positronium."

I didn't think about the bremsstrahlung from the alpha particles....

"The total power radiated in the two limiting cases is proportional to γ4 (a \perp v) or γ6 (a \parallel v). Since E = γmc2, we see that the total radiated power goes as m − 4 or m − 6, which accounts for why electrons lose energy to bremsstrahlung radiation much more rapidly than heavier charged particles (e.g., muons, protons, alpha particles). This is the reason a TeV energy electron-positron collider (such as the proposed International Linear Collider) cannot use a circular tunnel (requiring constant acceleration), while a proton-proton collider (such as the Large Hadron Collider) can utilize a circular tunnel. The electrons lose energy due to bremsstrahlung at a rate (m_p/m_e)^4 \approx 10^{13} times higher than protons do."

but apparently they decelerate relatively slow due to their large mass, producing longer wavelength radiation.