Table of Nuclides

Frequently Asked Questions

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2.1: Decay Data
Unit of Intensity

Could you please explain me the meaning of the column Intensity for beta ray and Gamma ray. Please take for example the diagram  for Cs137?
What is the meaning of the numbers inside the parentesis for Half life(3) and Q(17)

137CS B- DECAY Parent state: G.S.
Half life: 30.04 Y(3)
Q(gs): 1175.63(17) keV
Branch ratio:        1.0

Beta ray:

    Max.E(keV)    Avg.E(keV)     Intensity(rel)
      1176( 1)   416.264(72)       5.6( 2)
     892.1( -)   300.570(68)    5.8E-4( 8)
    514.03(23)   174.320(61)      94.4( 2)

Gamma ray:
   Energy(keV)    Intensity(rel)
     283.5( 1)    5.8E-4( 8)
   661.657( 3)      85.1( 2)


 Intensity is number of quata per 100 disintegration.  85.1 gamma quanta of 661.657 keV is emitted per 100 disintegration.
 You know about beta-ray.

 Those are uncertainty of last digits. It is a widely accepted convention.
  30.04 +- 0.03  and 1175.63 +- 0.17


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