No coin nor oath required. For personal study only.
This issue marks the further extension of the Nuclear Data Sheets to include the heavy elements. Nuclear Data Sheets for 213 < A < 228 were published in 1966 (Nuclear Data B1-5); a third compilation for 229 < A < 242 is in _preParation. I Final corrections to this issue have been made by members of the Nuclear Data Group in the absence of Dr. Wapstra.
Data have been considered from references included in the Nuclear Data Gro@ files as of March 1969, a-Particle Energies Alpha-particle energies have been corrected, where necessary, to a common set of calibration energies. Standard a-particle energies have been taken from A. H. Wapstra, Nucl. Phys. 57, 48 (1964). Changes in the data caused by use of the new standard energies are explicitly noted on the Sheets. Older, less precise ionization chamber measurements have not been revised although they are probably systematically low by about 0.1%. AQal = Q% -Q~l: where Qa = Ea+ Erecoil
The quantity AQai, which can be determlnedmore accurately than absolute values of Ea, is listed when reported by an experimenter.
The a-hindrance factor(the ratio of the measured partial half-life for a-emission to the theoretical half-life) was calculated for each transition by K. Poggenburg using the technique developed by H. Michel. The spin-independent equations of hi. A. Preston [Phys. Rev. 71, 865 (1947)] were used to calehlate theoretical half-lives for a-emlssion. The nuclear radius for each even-even nucleus was determined by assuming that the g.s. to g.s. a-transition is not hindered, i.e., the hindrance factor is one. For odd-A and odd-odd nuclei, the radius was chosen to be the average of the radii for the adjacent even-even nuclei. In the few cases where only one adjacent even-even radius was known, that value was "corrected for the A x/3 mass dependence and used in the calculation.
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i Available mass difference data have been combined in a least-squares adjustment program developed by Mattauch, TbieIe, and Wapstra [Nucl. Phys. 67, 73 (1965)]. All adopted Q-values and separation energies shown in this issue were taken from a new adjustment described by Wapstra et al. at the Winnipeg conference [
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