Re: Solution to Unusual Gamma Spec Spectrum -Reply

[Michael McNaughton <mcnaught@lanl.gov>]

At 02:18 PM 8/20/99 -0500, you wrote:
>Now.... would someone please explain "Doppler peak broadening"
>to the now-apparent gamma spec dunce (i.e., me)?

Let me try (for fun).

When an object such as a racing car is moving rapidly toward the listener,
the sound increases in frequency, and vice versa. Similarly, when an atom
is moving rapidly toward the detector, the frequency and energy increase,
and vice versa.

What would cause an atom to be moving rapidly? Answer: recoil after
emitting a massive object, in this case an alpha. The alpha has large mass
compared with the lithium atom, so the lithium recoils rapidly to conserve
momentum. Depending on the direction of recoil, the gamma may increase or
decrease in frequency and energy.

mike
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