[ RadSafe ] Beat phenomena and health physics

[JPreisig at aol.com]

Dear Radsafe,
 
     The phenomena of beats (see your undergraduate  text in 
physics/mechanics) involves what happens when 2 or more fundamental  frequencies of a 
system are close in frequency (or Energy)  to one  another.  Two such sinusoidal 
signals (or more) produce sum and difference  frequencies, which can be 
important in problems.
 
     I've been discussing beats concerning the  fundamental wobble 
frequencies.  I also said something perhaps about beats  and the Sodium doublet.
 
     Another situation where beats might be important  is in health physics 
and perhaps even physics.  We Health Physicists  measure gamma and other 
spectra using a MultiChannel Analyzer and similar  equipment.  There may be 
times when our gamma spectra have peaks that are  close to one another and may 
produce beat (sum and difference frequency)  peaks.  Do we observe such 
peaks in our spectra???  Will these beat  phenomena affect our physics 
results???  Quite possibly.  These extra  peaks may affect spectral stripping and 
other results.
 
     Remember,   E = h x nu, where nu is the  frequency in atomic and/or 
nuclear physics.
 
     Perhaps physicists doing sensitive experiments  account for such beat 
phenomena.  I don't remember hearing about beat  phenomena in my Health 
Physics courses.  I first heard about beat phenomena  in a physics course or 
two.  Then I heard about it again in geophysics  research.
 
     Beat phenomena might affect our every day Health  Physics work???  Oh 
my.
 
     I seem to remember Cesium-137 having closely  spaced decay (energy) 
gamma peaks.???
 
     Regards,    Joe Preisig