The Forbidden Beta-Decay ofSr90andY90

Small-Order Shape Factors inIn114,P32, andNichols1, McAdams2, Jensen3 1961Phys. Rev.

“…The beta transition to the ground state of Zr 90 must be once-forbidden, unique (A/=2, yes) from nuclear shell model considerations, 34 the log ft value, 34 and the spectral shape. 37 …”

Small-Order Effects in Beta Spectra

“…[11][12][13][14][15][16][17] As the shape factor for this transition is uniquely known, any deviations of the observed spectrum from that predicted by theory should result from instrumental errors.…”

“…Also, as a check on the instruments the unique firstforbidden spectrum of Y 90 was carefully examined. [11][12][13][14][15][16][17] The careful examination of this spectrum also served to indicate the validity with which this type of spectrum could be subtracted from a total beta spectrum.…”