Q2. What future works have the authors mentioned in the paper "Concerning the time dependence of the decay rate of 137 cs" ?
This result, in addition to the results of decay experiments listed in Table 1, indicates that the failure to observe the annual ( or other ) periodicity in one isotope does not exclude that possibility in others. In light of Table 1, the authors can state in general that their studies to date suggest the following: ( a ) not all nuclides exhibit variability in decay constants ; ( b ) among nuclides that do exhibit this variability, the patterns of variability ( e. g., amplitude and phase of any oscillation ) are not all the same ; and ( c ) for nuclides that do exhibit variability, the patterns themselves may vary over time.
Q3. How do the authors analyze the PTB data?
The authors have also analyzed the PTB measurements in terms of ‘‘phasegrams,’’ which are analogous to spectrograms, displaying the power as a function of time and phase for an assumed annual oscillation.
Q4. What is the significance of the ionization chambers?
One of the significant factors leading to the selection of ionization chambers in these types of measurements is their inherent stability with respect to systematic and environmental effects.
Q5. How long did the rod remain in the irradiator?
The rod was placed in the neutron irradiator for 5 min, activated, and then was placed in the counting bed and counted for fifteen minutes.
Q6. How many sources were used to determine the decay rate of 137Cs?
The 137Cs standard set referenced above, which was used to determine system stability and calibration, consisted of nineindividual sources of 0:5 mCi each.
Q7. What was the standard deviation of the 137Cs counts over a six month period?
Over a six month period of initial set-up and calibration, as reported in Cohn et al. (1969), the standard deviation of the 137Cs counts was 0.54%, implying good stability, and the background over the same period was 2:32 10470:56% counts/min over a 2:5 MeV spectrum window.
Q8. What is the simplest explanation for the difference in decay rates?
Based on the care and thorough effort in the design, construction and calibration of the counting system in the Ellis experiment, aimed at reducing possible background and systematic variations, it seems probable that the observed differences in the fluctuations in the measured decay rates are intrinsic to the 56Mn and 137Cs decays themselves.
Q9. What was the use of the counting system?
This counting system was utilized in conjunction with a broad beam neutron irradiator (Cohn et al., 1972), for the in vivo NAA experiments described in Ellis (1990), as mentioned above.