%0 Journal Article
%T Observation of Doppler broadening in $¦Â$-delayed proton-$¦Ã$ decay
%A S. B. Schwartz
%A C. Wrede
%A M. B. Bennett
%A S. N. Liddick
%A D. Perez-Loureiro
%A A. Bowe
%A A. A. Chen
%A K. A. Chipps
%A N. Cooper
%A D. Irvine
%A E. McNeice
%A F. Montes
%A F. Naqvi
%A R. Ortez
%A S. D. Pain
%A J. Pereira
%A C. Prokop
%A J. Quaglia
%A S. J. Quinn
%A J. Sakstrup
%A M. Santia
%A S. Shanab
%A A. Simon
%A A. Spyrou
%A E. Thiagalingam
%J Statistics
%D 2015
%I arXiv
%R 10.1103/PhysRevC.92.031302
%X Background: The Doppler broadening of $\gamma$-ray peaks due to nuclear recoil from $\beta$-delayed nucleon emission can be used to measure the energies of the nucleons. This method has never been tested using $\beta$-delayed proton emission or applied to a recoil heavier than $A=10$. Purpose: To test and apply this Doppler broadening method using $\gamma$-ray peaks from the $^{26}$P($\beta p\gamma$)$^{25}$Al decay sequence. Methods: A fast beam of $^{26}$P was implanted into a planar Ge detector, which was used as a $^{26}$P $\beta$-decay trigger. The SeGA array of high-purity Ge detectors was used to detect $\gamma$ rays from the $^{26}$P($\beta p\gamma$)$^{25}$Al decay sequence. Results: Radiative Doppler broadening in $\beta$-delayed proton-$\gamma$ decay was observed for the first time. The Doppler broadening analysis method was verified using the 1613 keV $\gamma$-ray line for which the proton energies were previously known. The 1776 keV $\gamma$ ray de-exciting the 2720 keV $^{25}$Al level was observed in $^{26}$P($\beta p\gamma$)$^{25}$Al decay for the first time and used to determine that the center-of-mass energy of the proton emission feeding the 2720-keV level is 5.1 $\pm$ 1.0 (stat.) $\pm$ 0.6 (syst.) MeV, corresponding to a $^{26}$Si excitation energy of 13.3 $\pm$ 1.0 (stat.) $\pm$ 0.6 (syst.) MeV for the proton-emitting level. Conclusions: The Doppler broadening method has been demonstrated to provide practical measurements of the energies for $\beta$-delayed nucleon emissions populating excited states of nuclear recoils at least as heavy as $A=25$.
%U http://arxiv.org/abs/1510.07652v1