Synchronous measurements of alpha-decay of 239 Pu carried out at north pole, antarctic, and in Puschino confirm that the shapes of the respective histograms depend on the diurnal rotation of the earth and on the direction of the alpha-particle
When the transfer of energy from the center and from the inner envelopes to the periphery occurs, alpha-particles leaving the nucleus surface have the energy excess equal to the energy difference between the corresponding levels, i.e.
Thus, when the excitation transfer from the third to the second envelope the energy of alpha-particles having two protons may be not more than 2 x 2.75 = 5.5 MeV, and when the excitation transfer from the fourth to the second envelope-- twice as much, not more than 11 MeV.
Experiments with collimators that allow studies of alpha-particle beams with definite directions indicate that this regularity is related to non-uniformity (anisotropy) of space [1,6].
In 2003, we found out that diurnal changes in histogram shapes also disappear when alpha-radioactivity is measured with collimators that issue alpha-particle beams directed towards the Pole star.
A histogram shape depends on a direction which alpha-particles
issued at radioactive decay follow; this was shown in measurements of [sup.239]Pu alpha-radioactivity fluctuations.
For initial operation before evaluating gamma-ray detector performance of the Sb[I.sub.3] detectors, [sup.241]Am alpha-particle energy spectra were recorded using the Sb[I.sub.3] detectors in a conventional measurement system comprising a preamplifier, bias supply, shaping amplifier, and a multichannel pulse-height analyzer.
Figures 8 and 9 show the alpha-particle energy spectra obtained from a typical Sb[I.sub.3] detector at room temperature.