Beta-delayed-neutron studies of $^{135,136}$Sb and $^{140}$I performed with trapped ions

• Main Authors: Alan, B. S, Caldwell, S. A, Scielzo, N. D, Czeszumska, A, Clark, J. A, Savard, G, Aprahamian, A, Burkey, M. T, Chiara, C. J, Harker, J, Levand, A. F, Marley, S. T, Morgan, G. E, Munson, J. M, Norman, E. B, Nystrom, A, Orford, R, Padgett, S. W, Galvan, A. Perez, Sharma, K. S, Siegl, K, Strauss, S. Y
• Format: Journal Article
• Language: English
• Published: 14-04-2019
• Subjects: Physics - Instrumentation and Methods for Astrophysics; Physics - Nuclear Experiment
• DOI: 10.48550/arxiv.1904.06623

Phys. Rev. C 101, 025806 (2020) Beta-delayed-neutron ($\beta$n) spectroscopy was performed using the
Beta-decay Paul Trap and an array of radiation detectors. The $\beta$n
branching ratios and energy spectra for $^{135,136}$Sb and $^{140}$I were
obtained by measuring the time of flight of recoil ions emerging from the
trapped ion cloud. These nuclei are located at the edge of an isotopic region
identified as having $\beta$n branching ratios that impact the r-process
abundance pattern around the A~130 peak. For $^{135,136}$Sb and $^{140}$I,
$\beta$n branching ratios of 14.6(11)%, 17.6(28)%, and 7.6(28)% were
determined, respectively. The $\beta$n energy spectra obtained for $^{135}$Sb
and $^{140}$I are compared with results from direct neutron measurements, and
the $\beta$n energy spectrum for $^{136}$Sb has been measured for the first
time.