β-delayed proton emission in the100Sn region

Abstract

β-delayed proton emission from nuclides in the neighborhood of 100 Sn was studied at the National Superconducting Cyclotron Laboratory. The nuclei were produced by fragmentation of a 120 MeV/nucleon 112 Sn primary beam on a Be target. Beam purification was provided by the A1900 Fragment Separator and the Radio Frequency Fragment Separator. The fragments of interest were identified and their decay was studied with the NSCL Beta Counting System (BCS) in conjunction with the Segmented Germanium Array (SeGA +1.9 −1.7 %, 1.3(5)%, 1.9(1)%, 7.5(5)% and 2.5(3)%, respectively. The b βp = 22(1)% for 101 Sn was deduced with higher precision than previously reported. The impact of the newly measured b βp values on the composition of the type-I X-ray burst ashes was studied.

Properties of γ -decaying isomers and isomeric ratios in the Sn100 region

“…Particle decay events were correlated to ion implantation events as described in Ref. [19], which used a similar set of segmented Si detectors. γ rays following decay events were detected with the Euroball-RIKEN Cluster Array (EURICA) [44], featuring a total of 84 HPGe crystals that surrounded WAS3ABi in a 4π geometry.…”

“…Among the relevant topics are the robustness of the N = Z = 50 shell closures in 100 Sn and the superallowed Gamow-Teller decay [1]; the limit of bound N = Z heavy nuclei and the location of the proton dripline; the role of T = 0 proton-neutron (pn) interactions in contrast isomers in 94 Ag, 96 Cd, and 98 In [3,[13][14][15][16][17][18][19]; and core-excited isomers in 96 Ag and 98 Cd [20][21][22]. This is by no means an exhaustive list.…”

Classical novae and type I X-ray bursts: Challenges for the 21st century

“…(Following a few recent measurements, 120, 241 we note that "laboratory" weak interaction rates are available for most species involved in XRBs; as well, beta-delayed proton decay seems to have little influence on model predictions, at least in the mass range A = 92-101. 242 ) Stellar weak interaction rates have previously been computed for different ranges of nuclei (e.g., A = 1-39; 243 A = 45-65; 244 A = 21-60; 245 A = 65-80 246 ). For some species, these rates may differ significantly from laboratory weak rates (see, e.g., Sarriguen 247 ) which may dramatically affect predictions of XRB light curves.…”

β -particle energy-summing correction for β -delayed proton emission measurements

“…β-delayed proton emission experiments can be used to populate proton-emitting states in nuclei which are otherwise difficult to access. Such proton-emitting states can be of interest to nuclear astrophysics and nuclear structure studies [1][2][3]. Rare-isotope beam facilities that produce short-lived isotopes either by projectile fragmentation or using the isotope separation online (ISOL) technique provide the opportunity to study the exotic nuclei which exhibit β-delayed proton emission, βp nuclei.…”

“…To date, the most common method for studying βp nuclei employs the production of nuclei via projectile fragmentation followed by the subsequent implantation of the βp nucleus into a double-sided silicon-strip detector (DSSD) with a thickness on the order of 50-1000 µm [e.g. References 1,2,[4][5][6][7]. After implantation into the DSSD, the βp nucleus undergoes β-delayed proton emission and the energy of the proton and the corresponding nuclear recoil (referred to here as the proton-decay energy) is then detected within the DSSD.…”