As the results obtained from the study of ²³³Pa
have been discussed at some length in earlier sections
of this chapter, this section will consist simply of a
recapitulation of the main conclusions.
1. γ-rays and internal conversion electrons.
In the region above 19 keV, 12 γ-rays have been identified from a study of their internal conversion electrons. The energies of the γ-rays agree well with
those given by Keller and Cork (1950) who, however,
list one additional weak γ -ray of 377 keV. The
relative intensities of the internal conversion electrons have been measured and the results agree well
with the values given by Elliott and Underhill (1952).
2. The spectrum at low energies. Interpretation
of the L-Auger spectrum is complicated by the presence
of internal conversion electrons, but the transitions
suggested to explain those lines definitely identified
as Auger lines are in agreement with transitions occurring in the spectra of RaE or RdTh or both. L conversion electrons of the 28.7 keV X-ray have been identified in the 7 keV region, and some evidence has been
obtained for a 17.2 keV γ-ray.
3. The continuous ß-spectra. The main part of
the (3-spectrum of ²³³Pa ends at 256 keV but there is a
low intensity partial spectrum extending to 568 keV.
These results agree very well with those of Elliott and
Underhill. The main part of the continuum has been
shown to consist of three partial ß-spectra, the
intensities of which have been roughly estimated.
4. Disintegration Scheme. The energies and intensities of the ß-spectra and of the γ-rays and internal conversion electrons fit satisfactorily into the
decay scheme given in Figure 5.14.
5. The number of electrons emitted per disintegration of ²³³Pa. The number of electrons emitted per
disintegration of ²³³Pa, excluding M and N -Auger electrons, was found to be 2.0 ± 0.15. This is lower than
the figures published by ICarraker (1951) and by Seaborg
(1942), but it is suggested that their values may include the M-Auger electrons and possibly an appreciable
fraction of the M x -rays.