| Autor: |
Kootte, B., Reiter, M. P., Andreoiu, C., Beck, S., Bergmann, J., Brunner, T., Dickel, T., Dietrich, K. A., Dilling, J., Dunling, E., Flowerdew, J., Graham, L., Gwinner, G., Hockenbery, Z., Izzo, C., Jacobs, A., Javaji, A., Klawitter, R., Lan, Y., Leistenschneider, E., Lykiardopoulou, E. M., Miskun, I., Mukul, I., Murböck, T., Paul, S. F., Plaß, W. R., Ringuette, J., Scheidenberger, C., Silwal, R., Simpson, R., Teigelhöfer, A., Thompson, R. I., Tracy, Jr., J. L., Vansteenkiste, M., Weil, R., Wieser, M. E., Will, C., Kwiatkowski, A. A. |
| Rok vydání: |
2024 |
| Předmět: |
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| Druh dokumentu: |
Working Paper |
| Popis: |
Direct observation of proton emission with very small emission energy is often unfeasible due to the long partial half-lives associated with tunneling through the Coulomb barrier. Therefore proton emitters with very small Q-values may require masses of both parent and daughter nuclei to establish them as proton unbound. Nuclear mass models have been used to predict the proton drip-line of the thulium (Tm) isotopic chain ($Z=69$), but up until now the proton separation energy has not been experimentally tested. Mass measurements were therefore performed using a Multiple Reflection Time-Of-Flight Mass Spectrometer (MR-TOF-MS) at TRIUMF's TITAN facility to definitively map the limit of proton-bound Tm. The masses of neutron-deficient, $^{149}$Tm and $^{150}$Tm, combined with measurements of $^{149m,g}$Er (which were found to deviate from literature by $\sim$150 keV), provide the first experimental confirmation that $^{149}$Tm is the first proton-unbound nuclide in the Tm chain. Our measurements also enable the strength of the $N=82$ neutron shell gap to be determined at the Tm proton drip-line, providing evidence supporting its continued existence. |
| Databáze: |
arXiv |
| Externí odkaz: |
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