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1. Probing exotic cross-shell interactions at N=28 with single-neutron transfer on 47K

Author

Paxman, C. J., Matta, A., Catford, W. N., Lotay, G., Assié, M., Clément, E., Lemasson, A., Ramos, D., Orr, N. A., Galtarossa, F., Girard-Alcindor, V., Dudouet, J., Achouri, N. L., Ackermann, D., Barrientos, D., Beaumel, D., Bednarczyk, P., Benzoni, G., Bracco, A., Canete, L., Cederwall, B., Ciemala, M., Delahaye, P., Doherty, D. T., Domingo-Pardo, C., Fernández-Domínguez, B., Fernández, D., Flavigny, F., Fougères, C., de France, G., Franchoo, S., Gadea, A., Gibelin, J., González, V., Gottardo, A., Goyal, N., Hammache, F., Harkness-Brennan, L. J., Harrouz, D. S., Jacquot, B., Judson, D. S., Jungclaus, A., Kaşkaş, A., Korten, W., Labiche, M., Lalanne, L., Lenain, C., Leoni, S., Ljungvall, J., Lois-Fuentes, J., Lokotko, T., Lopez-Martens, A., Maj, A., Marqués, F. M., Martel, I., Menegazzo, R., Mengoni, D., Million, B., Nyberg, J., Pérez-Vidal, R. M., Plagnol, L., Podolyák, Zs., Pullia, A., Quintana, B., Regueira-Castro, D., Reiter, P., Rejmund, M., Rezynkina, K., Sanchis, E., Şenyiğit, M., de Séréville, N., Siciliano, M., Sohler, D., Stezowski, O., Thomas, J. -C., Utepov, A., Valiente-Dobón, J. J., Verney, D., and Zielińska, M.

Subjects
Nuclear Experiment
Abstract

We present the first measurement of the $^{47}$K($d,p\gamma$)$^{48}$K transfer reaction, performed in inverse kinematics using a reaccelerated beam of $^{47}$K. The level scheme of $^{48}$K has been greatly extended with nine new bound excited states identified and spectroscopic factors deduced. Detailed comparisons with SDPF-U and SDPF-MU shell-model calculations reveal a number of discrepancies with these results, and a preference for SDPF-MU is found. Intriguingly, an apparent systematic overestimation of spectroscopic factors and a poor reproduction of the energies for 1$^-$ states suggests that the mixing between the $\pi s^{\,\,\,1}_{1/2} d^{\,\,\,4}_{3/2}$ and $\pi s^{\,\,\,2}_{1/2} d^{\,\,\,3}_{3/2}$ proton configurations in $^{48}$K is not correctly described using current interactions, challenging our descriptions of light $N=28$ nuclei., Comment: 7 pages, 3 figures, 1 table

Published
2024

2. Direct Measurement of Carbon Fusion at Astrophysical Energies with Gamma-Particle Coincidences

Author

Heine M., Fruet G., Courtin S., Jenkins D.G., Adsley P., Brown A., Canavan R., Catford W.N., Charon E., Curien D., Della Negra S., Duprat J., Hammache F., Lesrel J., Lotay G., Meyer A., Monpribat E., Montanari D., Morris L., Moukaddam M., Nippert J., Podolyák Zs., Regan P.H., Ribaud I., Richer M., Rudigier M., Shearman R., de Séréville N., and Stodel C.

Subjects
Physics, QC1-999
Abstract

We present 12C+12C direct fusion measurements with STELLA UKFATIMA, that reach into the region of astrophysics interest relevant to massive stars (M⊙ ≈ 25) using self-supporting thin rotating carbon foils [1]. We demonstrate that detecting gammas and light charged particles in coincidence with nanosecond timing is key for effective background reduction achieving reliable measurements in the sub-nanobarn range. We give details about core developments of the detection apparatus as well as the coincidence-analysis procedure of low count statistics. The present data largely follows the phenomenological hindrance interpolation and shows indication for resonant behaviour at the lowest energy explored.

Published
2022
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3. α decay of the neutron-deficient isotope At190

Author

Andreyev, AN, Seweryniak, D, Andel, B, Antalic, S, Doherty, DT, Korichi, A, Barton, C, Canete, L, Carpenter, MP, Clark, RM, Copp, PA, Cubiss, JG, Heery, J, Hrabar, Y, Huang, H, Huang, T, Karayonchev, V, Kondev, FG, Lauritsen, T, Liu, Z, Lotay, G, Müller-Gatermann, C, Nandi, S, Page, C, Potterveld, DH, Regan, PH, Reviol, W, Rudolph, D, Siciliano, M, Sidhu, RS, Sitarčík, A, Woods, PJ, Yue, Z, and Zhang, W

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract

The α decay of the neutron-deficient At190 isotope was observed following the Rh103(Zr90,3n)At190 reaction at Argonne National Laboratory. The reaction products were separated from the beam using the Argonne Gas-Filled Analyzer and implanted into a double-sided Si strip detector. The spatial and temporal correlations between implanted nuclei and subsequent α decays towards the known daughter isotope Bi186 were used to identify and characterize At190 nuclei. Two possible decay scenarios are proposed for the At190→Bi186 decay.

Published
2023

4. Cross Sections of the $^{83}$Rb(p,$\gamma)^{84}$Sr and $^{84}$Kr(p,$\gamma)^{85}$Rb Reactions at Energies Characteristic of the Astrophysical $\gamma$ Process

Author

Williams, M., Davids, B., Lotay, G., Nishimura, N., Rauscher, T., Gillespie, S. A., Alcorta, M., Amthor, A. M., Ball, G. C., Bhattacharjee, S. S., Bildstein, V., Catford, W. N., Doherty, D. T., Esker, N. E., Garnsworthy, A. B., Hackman, G., Hudson, K., Lennarz, A., Natzke, C., Olaizola, B., Psaltis, A., Svensson, C. E., Williams, J., Walter, D., and Yates, D.

Subjects
Nuclear Experiment, Astrophysics - Solar and Stellar Astrophysics
Abstract

We have measured the cross section of the $^{83}$Rb(p,$\gamma)^{84}$Sr radiative capture reaction in inverse kinematics using a radioactive beam of $^{83}$Rb at incident energies of 2.4 and $2.7 A$ MeV. Prior to the radioactive beam measurement, the $^{84}$Kr(p,$\gamma)^{85}$Rb radiative capture reaction was measured in inverse kinematics using a stable beam of $^{84}$Kr at an incident energy of $2.7 A$ MeV. The effective relative kinetic energies of these measurements lie within the relevant energy window for the $\gamma$ process in supernovae. The central values of the measured partial cross sections of both reactions were found to be $0.17-0.42$ times the predictions of statistical model calculations. Assuming the predicted cross section at other energies is reduced by the same factor leads to a slightly higher calculated abundance of the $p$ nucleus $^{84}$Sr, caused by the reduced rate of the $^{84}$Sr($\gamma$,p)$^{83}$Rb reaction derived from the present measurement., Comment: 11 pages, 11 figures. arXiv admin note: text overlap with arXiv:2109.06775

Published
2023
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5. Single neutron transfer on 23Ne and its relevance forthepathway ofnucleosynthesis in astrophysical X-ray bursts

Author

Lotay, G., Henderson, J., Catford, W. N., Ali, F. A., Berean, J., Bernier, N., Bhattacharjee, S. S., Bowry, M., Caballero-Folch, R., Davids, B., Drake, T. E., Garnsworthy, A. B., GhaziMoradi, F., Gillespie, S. A., Greaves, B., Hackman, G., Hallam, S., Hymers, D., Kasanda, E., Levy, D., Luna, B. K., Mathews, A., Meisel, Z., Moukaddam, M., Muecher, D., Olaizola, B., Orr, N. A., Patel, H. P., Rajabali, M. M., Saito, Y., Smallcombe, J., Spencer, M., Svensson, C. E., Whitmore, K., and Williams, M.

Subjects
Nuclear Experiment
Abstract

We present new experimental measurements of resonance strengths in the astrophysical 23Al(p, {\gamma})24Si reaction, constraining the pathway of nucleosynthesis beyond 22Mg in X-ray burster scenarios. Specifically, we have performed the first measurement of the (d, p) reaction using a radioactive beam of 23Ne to explore levels in 24Ne, the mirror analog of 24Si. Four strong single-particle states were observed and corresponding neutron spectroscopic factors were extracted with a precision of {\sim}20{\%}. Using these spectroscopic factors, together with mirror state identifications, we have reduced uncertainties in the strength of the key {\ell} = 0 resonance at Er= 157 keV, in the astrophysical 23Al(p, {\gamma}) reaction, by a factor of 4. Our results show that the 22Mg(p, {\gamma})23Al(p, {\gamma}) pathway dominates over the competing 22Mg({\alpha}, p) reaction in all but the most energetic X-ray burster events (T>0.85GK), significantly affecting energy production and the preservation of hydrogen fuel., Comment: 5 pages, 3 figures

Published
2022
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6. β-γ and isomeric decay spectroscopy of 168Dy

Author

Zhang G.X., Watanabe H., Kondev F.G., Lane G.J., Regan P.H., Söderström P.-A., Walker P.M., Kanaoka H., Korkulu Z., Lee P.S, Liu J.J, Nishimura S., Wu J., Yagi A., Ahn D.S., Alharbi T., Baba H., Browne F., Bruce A.M., Carroll R.J., Chae K.Y., Dombradi Zs., Doornenbal P., Estrade A., Fukuda N., Griffin C., Ideguchi E., Inabe N., Isobe T., Kanaya S., Kojouharov I., Kubo T., Kubono S., Kurz N., Kuti I., Lalkovski S., Lee C.S., Lee E.J., Lorusso G., Lotay G., Moon C.-B, Nishizuka I., Nita C.R., Odahara A., Patel Z., Phong V.H., Podolyák Zs., Roberts O.J., Sakurai H., Schaffner H., Shand C.M., Shimizu Y., Sumikama T., Suzuki H., Takeda H., Terashima S., Vajta Zs., Valiente-Dóbon J.J., and Xu Z.Y.

Subjects
Physics, QC1-999
Abstract

This contribution will report on the experimental work on the level structure of 168Dy. The experimental data have been taken as part of the EURICA decay spectroscopy campaign at RIBF, RIKEN in November 2014. In the experiment, a 238U primary beam is accelerated up to 345 MeV/u with an average intensity of 12 pnA. The nuclei of interest are produced by in-flight fission of 238U impinging on Be target with a thickness of 5 mm. The excited states of 168Dy have been populated through the decay from a newly identified isomeric state and via the β decay from 168Tb. In this contribution, scientific motivations, experimental procedure and some preliminary results for this study are presented.

Published
2018
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7. Fast-timing measurements in neutron-rich odd-mass zirconium isotopes using LaBr3:Ce detectors coupled with Gammasphere

Author

Gamba E.R., Lalkovski S., Rudigier M., Bruce A.M., Bottoni S., Carpenter M.P., Zhu S., Ayangeakaa A.D., Anderson J.T., Berry T.A., Burrows I., Carroll R.J., Copp P., Carmona Gallardo M., Cullen D.M., Daniel T., Greene J.P., Gurgi L.A., Hartley D.J., Ilieva R., Ilieva S., Janssens R.V.F., Kondev F.G., Kröll T., Lane G.J., Lauritsen T., Lazarus I., Lotay G., Fernández Martínez G., Podolyák Zs., Pucknell V., Reed M., Regan P.H., Rohrer J., Sethi J., Seweryniak D., Shand C.M., Simpson J., Smolen M., Stefanova E.A., Vedia V., and Yordanov O.

Subjects
Physics, QC1-999
Abstract

A fast-timing experiment was performed at the Argonne National Laboratory to measure the lifetimes of the lowest lying states of nuclei belonging to the deformed regions around mass number A≃110 and A≃150. These regions were populated via spontaneous fission of 252Cf and the gamma radiation following the decay of excited states in the fission fragments was measured using 51 Gammasphere detectors coupled with 25 LaBr3:Ce detectors. A brief description of the acquisition system and some preliminary results from the fast-timing analysis of the fission fragment 100Zr are presented. The lifetime value of τ = 840(65) ps was found for the 2+ state in 100Zr consistent within one standard deviation of the adopted value with 791 +26 -35ps. This is associated with a quadrupole deformation parameter of 0.36(2) which is within one standard deviation of the literature value of 0.3556+82 -57.

Published
2018
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8. Constraining the 19Ne(p,γ)20Na Reaction Rate Using a Direct Measurement at DRAGON

Author

Wilkinson R., Lotay G., Lennarz A., Ruiz C., Christian G., Akers C., Catford W. N., Chen A. A., Connolly D., Davids B., Hutcheon D. A., Jedrejcic D., Laird A. M., Martin L., McNeice E., Riley J., and Williams M.

Subjects
Physics, QC1-999
Abstract

A direct measurement of the 19Ne(p, γ)20 Na reaction has been performed in inverse kinematics at the DRAGON recoil separator, at an energy ∼ 10 keV higher than previous measurements. The key resonance in the 19 Ne + p system relevant for ONe novae and Type-I X-ray burst temperatures have been successfully measured for the first time. Preliminary estimates of the resonance energy and strength are reported as Ec.m. ≈ 458 keV and ωγ ≈ 18 meV. These results are consistent with previous direct measurements, but disagree with the most recent study of the 19Ne(p, γ)20 Na reaction rate. These preliminary results will be finalised after a forthcoming negative log-likelihood analysis.

Published
2017
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9. Isomer-delayed gamma-ray spectroscopy of neutron-rich 166Tb

Author

Gurgi L.A., Regan P.H., Söderström P.-A., Watanabe H., Walker P.M., Podolyák Zs., Nishimura S., Berry T.A., Doornenbal P., Lorusso G., Isobe T., Baba H., Xu Z.Y., Sakurai H., Sumikama T., Catford W.N., Bruce A.M., Browne F., Lane G.J., Kondev F.G., Odahara A., Wu J., Liu H.L., Xu F.R., Korkulu Z., Lee P., Liu J.J., Phong V.H., Yagi A., Zhang G.X., Alharbi T., Carroll R.J., Chae K.Y., Dombradi Zs., Estrade A., Fukuda N., Griffin C., Ideguchi E., Inabe N., Kanaoka H., Kojouharov I., Kubo T., Kubono S., Kurz N., Kuti I., Lalkovski S., Lee E.J., Lee C.S., Lotay G., Moon C.B., Nishizuka I., Nita C.R., Patel Z., Roberts O.J., Schaffner H., Shand C.M., Suzuki H., Takeda H., Terashima S., Vajta Zs., Kanaya S., and Valiente-Dobòn J.J.

Subjects
Physics, QC1-999
Abstract

This short paper presents the identification of a metastable, isomeric-state decay in the neutron-rich odd-odd, prolate-deformed nucleus 166Tb. The nucleus of interest was formed using the in-flight fission of a 345 MeV per nucleon 238U primary beam at the RIBF facility, RIKEN, Japan. Gamma-ray transitions decaying from the observed isomeric states in 166Tb were identified using the EURICA gamma-ray spectrometer, positioned at the final focus of the BigRIPS fragments separator. The current work identifies a single discrete gamma-ray transition of energy 119 keV which de-excites an isomeric state in 166Tb with a measured half-life of 3.5(4) μs. The multipolarity assignment for this transition is an electric dipole and is made on the basis internal conversion and decay lifetime arguments. Possible two quasi-particle Nilsson configurations for the initial and final states which are linked by this transition in 166Tb are made on the basis of comparison with Blocked BCS Nilsson calculations, with the predicted ground state configuration for this nucleus arising from the coupling of the v(1-/2)[521] and π(3+/2) Nilsson orbitals.

Published
2017
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10. First Direct Measurement of an Astrophysical p-Process Reaction Cross Section Using a Radioactive Ion Beam

Author

Lotay, G., Gillespie, S. A., Williams, M., Rauscher, T., Alcorta, M., Amthor, M., Andreoiu, C. A., Baal, D., Ball, G. C., Bhattacharjee, S. S., Behnamian, H., Bildstein, V., Burbadge, C., Catford, W. N., Doherty, D. T., Esker, N. E., Garcia, F. H., Garnsworthy, A. B., Hackman, G., Hallam, S., Hudson, K. A., Jazrawi, S., Kasanda, E., Kennington, A. R. L., Kim, Y. H., Lennarz, A., Lubna, R. S., Natzke, C. R., Nishimura, N., Olaizola, B., Paxman, C., Psaltis, A., Svensson, C. E., Williams, J., Wallis, B., Yates, D., Walter, D., and Davids, B.

Subjects
Nuclear Experiment
Abstract

We have performed the first direct measurement of the 83Rb(p,g) radiative capture reaction cross section in inverse kinematics using a radioactive beam of 83Rb at incident energies of 2.4 and 2.7 A MeV. The measured cross section at an effective relative kinetic energy of Ecm = 2.393 MeV, which lies within the relevant energy window for core collapse supernovae, is smaller than the prediction of statistical model calculations. This leads to the abundance of 84Sr produced in the astrophysical p process being higher than previously calculated. Moreover, the discrepancy of the present data with theoretical predictions indicates that further experimental investigation of p-process reactions involving unstable projectiles is clearly warranted., Comment: 6 pages, 4 figures, published in Physical Review Letters

Published
2021
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11. Study of ($^6$Li, $d$) and ($^6$Li, $t$) reactions on $^{22}$Ne and implications for $s$-process nucleosynthesis

Author

Ota, S., Christian, G., Catford, W. N., Lotay, G., Pignatari, M., Battino, U., Bennett, E. A., Dede, S., Doherty, D. T., Hallam, S., Herwig, F., Hooker, J., Hunt, C., Jayatissa, H., Matta, A., Mouhkaddam, M., Rao, E., Rogachev, G. V., Saastamoinen, A., Scriven, D., Tostevin, J. A., Upadhyayula, S., and Wilkinson, R.

Subjects
Nuclear Experiment
Abstract

We studied $\alpha$ cluster states in $^{26}$Mg via the $^{22}$Ne($^{6}$Li,$d\gamma$)$^{26}$Mg reaction in inverse kinematics at an energy of $7$ MeV/nucleon. States between $E_x$ = 4 - 12 MeV in $^{26}$Mg were populated and relative $\alpha$ spectroscopic factors were determined. Some of these states correspond to resonances in the Gamow window of the $^{22}$Ne($\alpha$,n)$^{25}$Mg reaction, which is one of the main neutron sources in the astrophysical $s$-process. We show that $\alpha$-cluster strength of the states analyzed in this work have critical impact on s-process abundances. Using our new $^{22}$Ne($\alpha$,n)$^{25}$Mg and $^{22}$Ne($\alpha$,$\gamma$)$^{26}$Mg reaction rates, we performed new s-process calculations for massive stars and Asymptotic Giant Branch stars and compared the resulting yields with the yields obtained using other $^{22}$Ne+$\alpha$ rates from the literature. We observe an impact on the s-process abundances up to a factor of three for intermediate-mass AGB stars and up to a factor of ten for massive stars. Additionally, states in $^{25}$Mg at $E_x$ $<$ 5 MeV are identified via the $^{22}$Ne($^{6}$Li,$t$)$^{25}$Mg reaction for the first time. We present the ($^6$Li, $t$) spectroscopic factors of these states and note similarities to the $(d,p$) reaction in terms of reaction selectivity.

Published
2021
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13. Decay properties of $^{22}\mathrm{Ne} + \alpha$ resonances and their impact on $s$-process nucleosynthesis

Author

Ota, S., Christian, G., Lotay, G., Catford, W. N., Bennett, E. A., Dede, S., Doherty, D. T., Hallam, S., Hooker, J., Hunt, C., Jayatissa, H., Matta, A., Moukaddam, M., Rogachev, G. V., Saastamoinen, A., Tostevin, J. A., Upadhyayula, S., and Wilkinson, R.

Subjects
Nuclear Experiment, Astrophysics - Solar and Stellar Astrophysics, Nuclear Theory
Abstract

The astrophysical $s$-process is one of the two main processes forming elements heavier than iron. A key outstanding uncertainty surrounding $s$-process nucleosynthesis is the neutron flux generated by the ${}^{22}\mathrm{Ne}(\alpha, n){}^{25}\mathrm{Mg}$ reaction during the He-core and C-shell burning phases of massive stars. This reaction, as well as the competing ${}^{22}\mathrm{Ne}(\alpha, \gamma){}^{26}\mathrm{Mg}$ reaction, is not well constrained in the important temperature regime from ${\sim} 0.2$--$0.4$~GK, owing to uncertainties in the nuclear properties of resonances lying within the Gamow window. To address these uncertainties, we have performed a new measurement of the ${}^{22}\mathrm{Ne}({}^{6}\mathrm{Li}, d){}^{26}\mathrm{Mg}$ reaction in inverse kinematics, detecting the outgoing deuterons and ${}^{25,26}\mathrm{Mg}$ recoils in coincidence. We have established a new $n / \gamma$ decay branching ratio of $1.14(26)$ for the key $E_x = 11.32$ MeV resonance in $^{26}\mathrm{Mg}$, which results in a new $(\alpha, n)$ strength for this resonance of $42(11)~\mu$eV when combined with the well-established $(\alpha, \gamma)$ strength of this resonance. We have also determined new upper limits on the $\alpha$ partial widths of neutron-unbound resonances at $E_x = 11.112,$ $11.163$, $11.169$, and $11.171$ MeV. Monte-Carlo calculations of the stellar ${}^{22}\mathrm{Ne}(\alpha, n){}^{25}\mathrm{Mg}$ and ${}^{22}\mathrm{Ne}(\alpha, \gamma){}^{26}\mathrm{Mg}$ rates, which incorporate these results, indicate that both rates are substantially lower than previously thought in the temperature range from ${\sim} 0.2$--$0.4$~GK., Comment: 17 pages, 4 figures, accepted for publication in Phys. Lett. B

Published
2020
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14. Shell evolution approaching the N=20 island of inversion: Structure of 29Mg

Author

Matta, A., Catford, W. N., Orr, N. A., Henderson, J., Ruotsalainen, P., Hackman, G., Garnsworthy, A. B., Delaunay, F., Wilkinson, R., Lotay, G., Tsunoda, Naofumi, Otsuka, Takaharu, Knapton, A. J., Ball, G. C., Bernier, N., Burbadge, C., Chester, A., Cross, D. S., Cruz, S., Diget, C. Aa., Domingo, T., Drake, T. E., Evitts, L. J., Garcia, F. H., Hallam, S., MacConnachie, E., Moukaddam, M., Muecher, D., Padilla-Rodal, E., Paetkau, O., Park, J., Pore, J. L., Rizwan, U., Smallcombe, J., Smith, J. K., Starosta, K., Svensson, C. E., Williams, J., and Williams, M.

Subjects
Nuclear Experiment
Abstract

The "Island of Inversion" for neutron-rich nuclei in the vicinity of N=20 has become the testing ground par excellence for our understanding and modelling of shell evolution with isospin. In this context, the structure of the transitional nucleus 29Mg is critical. The first quantitative measurements of the single particle structure of 29Mg are reported, using data from the d(28Mg,p gamma)29Mg reaction. Two key states carrying significant ell=3 (f-wave) strength were identified at 2.40 +/- 0.10 (Jpi = 5/2-) and 4.28 +/- 0.04 MeV (7/2-). New state-of-the-art shell model calculations have been performed and the predictions are compared in detail with the experimental results. Whilst the two lowest 7/2- levels are well described, the sharing of single-particle strength disagrees with experiment for both the 3/2- and 5/2- levels and there appear to be general problems with configurations involving the p3/2 neutron orbital and core-excited components. These conclusions are supported by an analysis of the neutron occupancies in the shell model calculations., Comment: 15 pages, 10 figures, 4 tables

Published
2019
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15. Direct Measurement of Astrophysically Important Resonances in $^{38}\mathrm{K}(p, \gamma){}^{39}\mathrm{Ca}$

Author

Christian, G., Lotay, G., Ruiz, C., Akers, C., Burke, D. S., Catford, W. N., Chen, A. A., Connolly, D., Davids, B., Fallis, J., Hager, U., Hutcheon, D., Mahl, A., Rojas, A., and Sun, X.

Subjects
Nuclear Experiment, Astrophysics - Solar and Stellar Astrophysics
Abstract

According to sensitivity studies, the $^{38}\mathrm{K}\left( p, \gamma \right){}^{39}\mathrm{Ca}$ reaction has a significant influence on $\mathrm{Ar}$, $\mathrm{K}$, and $\mathrm{Ca}$ production in classical novae. In order to constrain the rate of this reaction, we have performed a direct measurement of the strengths of three candidate $\ell = 0$ resonances within the Gamow window, at $386 \pm 10~\mathrm{keV}$, $515 \pm 10~\mathrm{keV}$, and $689 \pm 10~\mathrm{keV}$. The experiment was performed in inverse kinematics using a beam of unstable $^{38}\mathrm{K}$ impinged on a windowless $\mathrm{H}_2$ target. The $^{39}\mathrm{Ca}$ recoils and prompt $\gamma$ rays from $^{38}\mathrm{K}\left( p, \gamma \right){}^{39}\mathrm{Ca}$ reactions were detected in coincidence using a recoil mass separator and a BGO array, respectively. For the $689$ keV resonance, we observed a clear recoil-$\gamma$ coincidence signal and extracted resonance strength and energy values of $120^{+50}_{-30}~\mathrm{(stat.)}^{+20}_{-60}~\mathrm{(sys.)}~\mathrm{meV}$ and $679^{+2}_{-1}~\mathrm{(stat.)} \pm 1~\mathrm{(sys.)}~\mathrm{keV}$, respectively. We also performed a singles analysis, extracting a resonance strength of $120 \pm 20~\mathrm{(stat.)} \pm 15~\mathrm{(sys.)}~\mathrm{meV}$, consistent with the coincidence result. For the $386$ keV and $515$ keV resonances, we extract $90\%$ confidence level upper limits of $2.54$ meV and $18.4$ meV, respectively. We have established a new recommended $^{38}\mathrm{K}(p, \gamma){}^{39}\mathrm{Ca}$ rate based on experimental information, which reduces overall uncertainties near the peak temperatures of nova burning by a factor of ${\sim} 250$. Using the rate obtained in this work in model calculations of the hottest oxygen-neon novae reduces overall uncertainties on $\mathrm{Ar}$, $\mathrm{K}$, and $\mathrm{Ca}$ synthesis to factors of $15$ or less in all cases., Comment: 11 pages, 6 figures, accepted for publication in Phys. Rev. C

Published
2018
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16. The rate of the astrophysical 48Cr(p,γ)49Mn reaction and its influence on the potential A = 48 waiting point in the rp process

Author

O'Shea, C., primary, Lotay, G., additional, Doherty, D.T., additional, Seweryniak, D., additional, Lau, R., additional, Bartram, G., additional, Byrne, S., additional, Canete, L., additional, Carpenter, M.P., additional, Chipps, K.A., additional, Copp, P.A., additional, Cousins, C., additional, Henderson, J., additional, Huang, T., additional, Jayatissa, H., additional, Kondev, F., additional, Müller-Gatermann, C., additional, Pain, S.D., additional, Paxman, C., additional, Reed, B.J., additional, Reviol, W., additional, Rogers, A.M., additional, Russell, R., additional, Schatz, H., additional, and Siciliano, M., additional

Published
2024
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17. Spectroscopy of proton-rich 66^Se up to J^{\pi} = 6^+: isospin-breaking effect in the A = 66 isobaric triplet

Author

Ruotsalainen, P., Jenkins, D. G., Bentley, M. A., Auranen, K., Davies, P. J., Grahn, T., Greenlees, P. T., Henderson, J., Herzáň, A., Jakobsson, U., Joshi, P., Julin, R., Juutinen, S., Konki, J., Leino, M., Lotay, G., Nichols, A. J., Obertelli, A., Pakarinen, J., Partanen, J., Peura, P., Rahkila, P., Sandzelius, M., Sarén, J., Scholey, C., Sorri, J., Stolze, S., Uusitalo, J., and Wadsworth, R.

Subjects
Nuclear Experiment
Abstract

Candidates for three excited states in the 66^Se have been identified using the recoil-{\beta} tagging method together with a veto detector for charged-particle evaporation channels. These results allow a comparison of mirror and triplet energy differences between analogue states across the A = 66 triplet as a function of angular momentum. The extracted triplet energy differences follow the negative trend observed in the f_7/2 shell. Shell-model calculations indicate a continued need for an additional isospin non-conserving interaction in addition to the Coulomb isotensor part as a function of mass., Comment: Submitted to Physical Review Letters on Jul. 18, 2013. 5 pages, 3 figures

Published
2013
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18. Measurement of the 18Ne(a,p_0)21Na reaction cross section in the burning energy region for X-ray bursts

Author

Salter, P. J. C., Aliotta, M., Davinson, T., Falou, H. Al, Chen, A., Davids, B., Fulton, B. R., Galinski, N., Howell, D., Lotay, G., Machule, P., Murphy, A. StJ., Ruiz, C., Sjue, S., Taggart, M., Walden, P., and Woods, P. J.

Subjects
Nuclear Experiment
Abstract

The 18Ne(a,p)21Na reaction provides one of the main HCNO-breakout routes into the rp-process in X-ray bursts. The 18Ne(a,p_0)21Na reaction cross section has been determined for the first time in the Gamow energy region for peak temperatures T=2GK by measuring its time-reversal reaction 21Na(p,a)18Ne in inverse kinematics. The astrophysical rate for ground-state to ground-state transitions was found to be a factor of 2 lower than Hauser-Feshbach theoretical predictions. Our reduced rate will affect the physical conditions under which breakout from the HCNO cycles occurs via the 18Ne(a,p)21Na reaction., Comment: 5 pages, 3 figures, accepted for publication on Physical Review Letters

Published
2012
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19. Spectroscopy of $^{18}$Na: Bridging the two-proton radioactivity of $^{19}$Mg

Author

Assié, M., Santos, F. de Oliveira, Davinson, T., de Grancey, F., Achouri, L., Alcántara-Núñez, J., Kalanee, T. Al, Angélique, J. -C., Borcea, C., Borcea, R., Caceres, L., Celikovic, I., Chudoba, V., Pang, D. Y., Ducoin, C., Fallot, M., Kamalou, O., Kiener, J., Lam, Y., Lefebvre-Schuhl, A., Lotay, G., Mrazek, J., Perrot, L., Sánchez-Benítez, A. M., Rotaru, F., Saint-Laurent, M-G., Sobolev, Yu., Smirnova, N., Stanoiu, M., Stefan, I., Subotic, K., Ujic, P., Wolski, R., and Woods, P. J.

Subjects
Nuclear Experiment
Abstract

The unbound nucleus $^{18}$Na, the intermediate nucleus in the two-proton radioactivity of $^{19}$Mg, was studied by the measurement of the resonant elastic scattering reaction $^{17}$Ne(p,$^{17}$Ne)p performed at 4 A.MeV. Spectroscopic properties of the low-lying states were obtained in a R-matrix analysis of the excitation function. Using these new results, we show that the lifetime of the $^{19}$Mg radioactivity can be understood assuming a sequential emission of two protons via low energy tails of $^{18}$Na resonances.

Published
2011
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20. Confirmation of a new resonance in Si26 and contribution of classical novae to the galactic abundance of Al26

Author

Canete, L., primary, Doherty, D. T., additional, Lotay, G., additional, Seweryniak, D., additional, Campbell, C. M., additional, Carpenter, M. P., additional, Catford, W. N., additional, Chipps, K. A., additional, Henderson, J., additional, Izzard, R. G., additional, Janssens, R. V. F., additional, Jayatissa, H., additional, José, J., additional, Kennington, A. R. L., additional, Kondev, F. G., additional, Korichi, A., additional, Lauritsen, T., additional, Müller-Gatermann, C., additional, Paxman, C., additional, Podolyák, Zs., additional, Reed, B. J., additional, Regan, P. H., additional, Reviol, W., additional, Siciliano, M., additional, Wilson, G. L., additional, Yates, R., additional, and Zhu, S., additional

Published
2023
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21. Isomer spectroscopy of neutron-rich 168Tb103

Author

Gurgi, L.A., Regan, P.H., Söderström, P.-A., Watanabe, H., Walker, P.M., Podolyák, Zs., Nishimura, S., Berry, T.A., Doornenbal, P., Lorusso, G., Isobe, T., Baba, H., Xu, Z.Y., Sakurai, H., Sumikama, T., Catford, W.N., Bruce, A.M., Browne, F., Lane, G.J., Kondev, F.G., Odahara, A., Wu, J., Liu, H.L., Xu, F.R., Korkulu, Z., Lee, P., Liu, J.J., Phong, V.H., Yag, A., Zhang, G.X., Alharbi, T., Carroll, R.J., Chae, K.Y., Dombradi, Zs., Estrade, A., Fukuda, N., Griffin, C., Ideguchi, E., Inabe, N., Kanaoka, H., Kojouharov, I., Kubo, T., Kubono, S., Kurz, N., Kuti, I., Lalkovski, S., Lee, E.J., Lee, C.S., Lotay, G., Moon, C.-B., Nishizuka, I., Nita, C.R., Patel, Z., Roberts, O.J., Schaffner, H., Shand, C.M., Suzuki, H., Takeda, H., Terashima, S., Vajta, Zs., Yoshida, S., and Valiente-Dòbon, J.J.

Published
2017
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25. Cross sections of the Rb83(p,γ)Sr84 and Kr84(p,γ)Rb85 reactions at energies characteristic of the astrophysical γ process

Author

Williams, M., primary, Davids, B., additional, Lotay, G., additional, Nishimura, N., additional, Rauscher, T., additional, Gillespie, S. A., additional, Alcorta, M., additional, Amthor, A. M., additional, Ball, G. C., additional, Bhattacharjee, S. S., additional, Bildstein, V., additional, Catford, W. N., additional, Doherty, D. T., additional, Esker, N. E., additional, Garnsworthy, A. B., additional, Hackman, G., additional, Hudson, K., additional, Lennarz, A., additional, Natzke, C., additional, Olaizola, B., additional, Psaltis, A., additional, Svensson, C. E., additional, Williams, J., additional, Walter, D., additional, and Yates, D., additional

Published
2023
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26. Progress on nuclear reaction rates affecting the stellar production of 26Al

Author

Laird, A M, primary, Lugaro, M, additional, Kankainen, A, additional, Adsley, P, additional, Bardayan, D W, additional, Brinkman, H E, additional, Côté, B, additional, Deibel, C M, additional, Diehl, R, additional, Hammache, F, additional, den Hartogh, J W, additional, José, J, additional, Kurtulgil, D, additional, Lederer-Woods, C, additional, Lotay, G, additional, Meynet, G, additional, Palmerini, S, additional, Pignatari, M, additional, Reifarth, R, additional, de Séréville, N, additional, Sieverding, A, additional, Stancliffe, R J, additional, Trueman, T C L, additional, Lawson, T, additional, Vink, J S, additional, Massimi, C, additional, and Mengoni, A, additional

Published
2023
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27. Single neutron transfer on Ne and its relevance for the pathway of nucleosynthesis in astrophysical X-ray bursts

Author

Lotay, G., Henderson, J., Catford, W.N., Ali, F.A., Berean, J., Bernier, N., Bhattacharjee, S.S., Bowry, M., Caballero-Folch, R., Davids, B., Drake, T.E., Garnsworthy, A.B., Ghazi Moradi, F., Gillespie, S.A., Greaves, B., Hackman, G., Hallam, S., Hymers, D., Kasanda, E., Levy, D., Luna, B.K., Mathews, A., Meisel, Z., Moukaddam, M., Muecher, D., Olaizola, B., Orr, N.A., Patel, H.P., Rajabali, M.M., Saito, Y., Smallcombe, J., Spencer, M., Svensson, C.E., Whitmore, K., and Williams, M.

Abstract

We present new experimental measurements of resonance strengths in the astrophysical $^{23}$Al(p,γ)$^{24}$Si reaction, constraining the pathway of nucleosynthesis beyond $^{22}$Mg in X-ray burster scenarios. Specifically, we have performed the first measurement of the (d,p) reaction using a radioactive beam of $^{23}$Ne to explore levels in $^{24}$Ne, the mirror analog of $^{24}$Si. Four strong single-particle states were observed and corresponding neutron spectroscopic factors were extracted with a precision of ∼20%. Using these spectroscopic factors, together with mirror state identifications, we have reduced uncertainties in the strength of the key ℓ = 0 resonance at Er = 157 keV, in the astrophysical $^{23}$Al(p,γ) reaction, by a factor of 4. Our results show that the $^{22}$Mg(p,γ)$^{23}$Al(p,γ) pathway dominates over the competing $^{22}$Mg(α,p) reaction in all but the most energetic X-ray burster events (T>0.85 GK), significantly affecting energy production and the preservation of hydrogen fuel.

Published
2022

28. Single neutron transfer on 23Ne and its relevance for the pathway of nucleosynthesis in astrophysical X-ray bursts

Author

Lotay, G., primary, Henderson, J., additional, Catford, W.N., additional, Ali, F.A., additional, Berean, J., additional, Bernier, N., additional, Bhattacharjee, S.S., additional, Bowry, M., additional, Caballero-Folch, R., additional, Davids, B., additional, Drake, T.E., additional, Garnsworthy, A.B., additional, Ghazi Moradi, F., additional, Gillespie, S.A., additional, Greaves, B., additional, Hackman, G., additional, Hallam, S., additional, Hymers, D., additional, Kasanda, E., additional, Levy, D., additional, Luna, B.K., additional, Mathews, A., additional, Meisel, Z., additional, Moukaddam, M., additional, Muecher, D., additional, Olaizola, B., additional, Orr, N.A., additional, Patel, H.P., additional, Rajabali, M.M., additional, Saito, Y., additional, Smallcombe, J., additional, Spencer, M., additional, Svensson, C.E., additional, Whitmore, K., additional, and Williams, M., additional

Published
2022
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29. Angle-integrated measurements of the 26Al (d, n)27Si reaction cross section: a probe of spectroscopic factors and astrophysical resonance strengths

Author

Kankainen, A., Woods, P. J., Nunes, F., Langer, C., Schatz, H., Bader, V., Baugher, T., Bazin, D., Brown, B. A., Browne, J., Doherty, D. T., Estrade, A., Gade, A., Kontos, A., Lotay, G., Meisel, Z., Montes, F., Noji, S., Perdikakis, G., Pereira, J., Recchia, F., Redpath, T., Stroberg, R., Scott, M., Seweryniak, D., Stevens, J., Weisshaar, D., Wimmer, K., and Zegers, R.

Published
2016
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30. Revised decay properties of the key 93-keV resonance in the Mg25(p,γ) reaction and its influence on the MgAl cycle in astrophysical environments

Author

Lotay, G., primary, Doherty, D. T., additional, Janssens, R. V. F., additional, Seweryniak, D., additional, Albers, H. M., additional, Almaraz-Calderon, S., additional, Carpenter, M. P., additional, Champagne, A. E., additional, Chiara, C. J., additional, Hoffman, C. R., additional, Iliadis, C., additional, Kankainen, A., additional, Lauritsen, T., additional, and Zhu, S., additional

Published
2022
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31. Revised decay properties of the key 93-keV resonance in the 25Mg(p,γ) reaction and its influence on the MgAl cycle in astrophysical environments

Author

Lotay, G., Doherty, D. T., Janssens, R. V. F., Seweryniak, D., Albers, H. M., Almaraz-Calderon, S., Carpenter, M. P., Champagne, A. E., Chiara, C. J., Hoffman, C. R., Iliadis, C., Kankainen, A., Lauritsen, T., and Zhu, S.

Subjects
astrofysiikka, magnesium, alumiini, gammasäteily, ydinfysiikka, kosminen säteily
Abstract

The γ-decay properties of an excited state in 26Al at 6398.3(8) keV have been reexamined using the 11B+16O fusion-evaporation reaction. This level represents a key 93.1(8)-keV resonance in the 25Mg+p system and its relative branching to the 26Al ground state, f0, has been determined to be 0.76±0.03 (stat.) ±0.10 (syst.). This is a significantly higher value than the most recent evaluation and implies a considerable increase in the production of cosmic γ rays from 26Al radioactivity. peerReviewed

Published
2022

32. Revised decay properties of the key 93-keV resonance in the Mg 25 (p,γ) reaction and its influence on the MgAl cycle in astrophysical environments

Author

Lotay, G., Almaraz-Calderon, S., Zhu, S., Champagne, A.E., Janssens, R.V.F., Albers, H.M., Kankainen, A., Iliadis, C., Lauritsen, T., Seweryniak, D., Hoffman, C.R., Carpenter, M.P., Doherty, D.T., and Chiara, C.J.

Abstract

The γ-decay properties of an excited state in Al26 at 6398.3(8) keV have been reexamined using the B11+O16 fusion-evaporation reaction. This level represents a key 93.1(8)-keV resonance in the Mg25+p system and its relative branching to the Al26 ground state, f0, has been determined to be 0.76±0.03 (stat.) ±0.10 (syst.). This is a significantly higher value than the most recent evaluation and implies a considerable increase in the production of cosmic γ rays from Al26 radioactivity.

Published
2022
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33. Radiative Capture on Nuclear Isomers: Direct Measurement of the Al26m(p,γ)Si27 Reaction

Author

Lotay, G., primary, Lennarz, A., additional, Ruiz, C., additional, Akers, C., additional, Chen, A. A., additional, Christian, G., additional, Connolly, D., additional, Davids, B., additional, Davinson, T., additional, Fallis, J., additional, Hutcheon, D. A., additional, Machule, P., additional, Martin, L., additional, Mountford, D. J., additional, and Murphy, A. St. J., additional

Published
2022
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34. (Li6, d) and (Li6, t) reactions on Ne22 and implications for s -process nucleosynthesis

Author

Ota, S., primary, Christian, G., additional, Catford, W. N., additional, Lotay, G., additional, Pignatari, M., additional, Battino, U., additional, Bennett, E. A., additional, Dede, S., additional, Doherty, D. T., additional, Hallam, S., additional, Herwig, F., additional, Hooker, J., additional, Hunt, C., additional, Jayatissa, H., additional, Matta, A., additional, Moukaddam, M., additional, Rao, E., additional, Rogachev, G. V., additional, Saastamoinen, A., additional, Scriven, D., additional, Tostevin, J. A., additional, Upadhyayula, S., additional, and Wilkinson, R., additional

Published
2021
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35. First Direct Measurement of an Astrophysical p -Process Reaction Cross Section Using a Radioactive Ion Beam

Author

Lotay, G., primary, Gillespie, S. A., additional, Williams, M., additional, Rauscher, T., additional, Alcorta, M., additional, Amthor, A. M., additional, Andreoiu, C. A., additional, Baal, D., additional, Ball, G. C., additional, Bhattacharjee, S. S., additional, Behnamian, H., additional, Bildstein, V., additional, Burbadge, C., additional, Catford, W. N., additional, Doherty, D. T., additional, Esker, N. E., additional, Garcia, F. H., additional, Garnsworthy, A. B., additional, Hackman, G., additional, Hallam, S., additional, Hudson, K. A., additional, Jazrawi, S., additional, Kasanda, E., additional, Kennington, A. R. L., additional, Kim, Y. H., additional, Lennarz, A., additional, Lubna, R. S., additional, Natzke, C. R., additional, Nishimura, N., additional, Olaizola, B., additional, Paxman, C., additional, Psaltis, A., additional, Svensson, C. E., additional, Williams, J., additional, Wallis, B., additional, Yates, D., additional, Walter, D., additional, and Davids, B., additional

Published
2021
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36. New constraints on the Al25(p,γ) reaction and its influence on the flux of cosmic γ rays from classical nova explosions

Author

Canete, L., primary, Lotay, G., additional, Christian, G., additional, Doherty, D. T., additional, Catford, W. N., additional, Hallam, S., additional, Seweryniak, D., additional, Albers, H. M., additional, Almaraz-Calderon, S., additional, Bennett, E. A., additional, Carpenter, M. P., additional, Chiara, C. J., additional, Greene, J. P., additional, Hoffman, C. R., additional, Janssens, R. V. F., additional, José, J., additional, Kankainen, A., additional, Lauritsen, T., additional, Matta, A., additional, Moukaddam, M., additional, Ota, S., additional, Saastamoinen, A., additional, Wilkinson, R., additional, and Zhu, S., additional

Published
2021
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37. Storage ring at HIE-ISOLDE: Technical design report

Author

Grieser, M., Litvinov, Yu. A., Raabe, R., Blaum, K., Blumenfeld, Y., Butler, P. A., Wenander, F., Woods, P. J., Aliotta, M., Andreyev, A., Artemyev, A., Atanasov, D., Aumann, T., Balabanski, D., Barzakh, A., Batist, L., Bernardes, A. -P., Bernhardt, D., Billowes, J., Bishop, S., Borge, M., Borzov, I., Bosch, F., Boston, A. J., Brandau, C., Catford, W., Catherall, R., Cederkäll, J., Cullen, D., Davinson, T., Dillmann, I., Dimopoulou, C., Dracoulis, G., Düllmann, Ch. E., Egelhof, P., Estrade, A., Fischer, D., Flanagan, K., Fraile, L., Fraser, M. A., Freeman, S. J., Geissel, H., Gerl, J., Greenlees, P., Grisenti, R. E., Habs, D., von Hahn, R., Hagmann, S., Hausmann, M., He, J. J., Heil, M., Huyse, M., Jenkins, D., Jokinen, A., Jonson, B., Joss, D. T., Kadi, Y., Kalantar-Nayestanaki, N., Kay, B. P., Kiselev, O., Kluge, H. -J., Kowalska, M., Kozhuharov, C., Kreim, S., Kröll, T., Kurcewicz, J., Labiche, M., Lemmon, R. C., Lestinsky, M., Lotay, G., Ma, X. W., Marta, M., Meng, J., Mücher, D., Mukha, I., Müller, A., Murphy, A. St J., Neyens, G., Nilsson, T., Nociforo, C., Nörtershäuser, W., Page, R. D., Pasini, M., Petridis, N., Pietralla, N., Pfützner, M., Podolyák, Z., Regan, P., Reed, M. W., Reifarth, R., Reiter, P., Repnow, R., Riisager, K., Rubio, B., Sanjari, M. S., Savin, D. W., Scheidenberger, C., Schippers, S., Schneider, D., Schuch, R., Schwalm, D., Schweikhard, L., Shubina, D., Siesling, E., Simon, H., Simpson, J., Smith, J., Sonnabend, K., Steck, M., Stora, T., Stöhlker, T., Sun, B., Surzhykov, A., Suzaki, F., Tarasov, O., Trotsenko, S., Tu, X. L., Van Duppen, P., Volpe, C., Voulot, D., Walker, P. M., Wildner, E., Winckler, N., Winters, D. F. A., Wolf, A., Xu, H. S., Yakushev, A., Yamaguchi, T., Yuan, Y. J., Zhang, Y. H., and Zuber, K.

Published
2012
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38. Level structure of the Tz=-1 nucleus Ar 34 and its relevance for nucleosynthesis in ONe novae

Author

Kennington, A. R. L., Lotay, G., Doherty, D.T., Seweryniak, D., Andreoiu, C., Auranen, K., Carpenter, M. P., Catford, W.N., Deibel, C. M., Hadynska-Klek, K., Hallam, S., Hoff, D. E. M., Huang, T., Janssens, R. V. F., Jazrawi, S., José, J., Kondev, F.G., Lauritsen, T., Li, J., Rogers, A. M., Saiz, J., Savard, G., Stolze, S., Wilson, G. L., Zhu, S., Department of Energy (US), Science and Technology Facilities Council (UK), Natural Sciences and Engineering Research Council of Canada, Ministerio de Economía y Competitividad (España), Generalitat de Catalunya, Ministerio de Ciencia e Innovación (España), and European Commission

Subjects
Nuclear Experiment
Abstract

The Mg24+C12 fusion reaction was used to perform a detailed γ-ray spectroscopy study of the astrophysically important nucleus Ar34. In particular, an experimental setup, coupling the advanced γ-ray tracking array GRETINA with the well-established Argonne fragment mass analyzer (FMA), was employed to obtain excitation energies and spin-parity assignments for excited states in Ar34, both above and below the proton separation energy. For the first time, an angular distribution analysis of in-beam γ rays from fusion-evaporation reactions, using a tracking array, has been performed and Coulomb energy differences of analog states in the T=1, A=34 mirror system, explored from 0 to 6 MeV. Furthermore, we present a comprehensive discussion of the astrophysical Cl33(p,γ) stellar reaction rate, together with implications for the identification of nova presolar grains from sulfur isotopic abundances., This work was supported by the U. S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract No. DEAC02-06CH11357 and Grants No. DEFG02- 94-ER40834, No. DEFG02-97-ER41041, No. DEFG02- 97-ER41043, No. DEFG02-94-ER40848, and No. DESC0014231. United Kingdom personnel were supported by the Science and Technologies Facilities Council (STFC) and C.A. was supported by the Natural Sciences and Engineering Research Council of Canada. J.J. acknowledges support from Spanish MINECO Grant No. AYA2017-86274-P, the E.U. FEDER funds, and AGAUR/Generalitat de Catalunya Grant No. SGR-661/2017. This research uses resources of ANL’s ATLAS facility, which is a DOE Office of Science User facility

Published
2021
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39. New constraints on the Al 25 (p,γ) reaction and its influence on the flux of cosmic γ rays from classical nova explosions

Author

Matta, A., Bennett, E.A., Almaraz-Calderon, S., Doherty, D.T., Moukaddam, M., Chiara, C.J, Carpenter, M.P., Ota, S., Saastamoinen, A., Kankainen, A., José, J., Hoffman, C.R., Greene, J.P., Catford, W.N., Hallam, S., Canete, L., Wilkinson, R., Lauritsen, T., Janssens, R.V.F., Zhu, S., Albers, H.M., Christian, G., Seweryniak, D., and Lotay, G.

Abstract

The astrophysical Al25(p,γ)Si26 reaction represents one of the key remaining uncertainties in accurately modeling the abundance of radiogenic Al26 ejected from classical novae. Specifically, the strengths of key proton-unbound resonances in Si26, that govern the rate of the Al25(p,γ) reaction under explosive astrophysical conditions, remain unsettled. Here, we present a detailed spectroscopy study of the Si26 mirror nucleus Mg26. We have measured the lifetime of the 3+, 6.125-MeV state in Mg26 to be 19(3)fs and provide compelling evidence for the existence of a 1- state in the T=1,A=26 system, indicating a previously unaccounted for=1 resonance in the Al25(p,γ) reaction. Using the presently measured lifetime, together with the assumption that the likely 1- state corresponds to a resonance in the Al25+p system at 435.7(53) keV, we find considerable differences in the Al25(p,γ) reaction rate compared to previous works. Based on current nova models, we estimate that classical novae may be responsible for up to ≈15% of the observed galactic abundance of Al26.

Published
2021
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40. New constraints on the Al 25 (p,γ) reaction and its influence on the flux of cosmic γ rays from classical nova explosions

Author

Canete, L., Lotay, G., Christian, G., Doherty, D.T., Catford, W. N., Hallam, S., Seweryniak, D., Albers, H. M., Almaraz-Calderón, S., Bennett, E. Andrew, Carpenter, M. P., Chiara, C. J., Greene, J. P., Hoffman, C. R., Janssens, R. V. F., Kankainen, A., Lauritsen, T., Matta, A., Moukaddam, M., Department of Energy (US), Science and Technology Facilities Council (UK), Ministerio de Economía y Competitividad (España), and Generalitat de Catalunya

Subjects
Nucleon induced nuclear reactions, Radiative capture, Nuclear astrophysics, Nuclear reactions, Lifetimes and widths, Nuclear structure and decays, Nucleosynthesis in explosive environments
Abstract

The astrophysical Al25(p,γ)Si26 reaction represents one of the key remaining uncertainties in accurately modeling the abundance of radiogenic Al26 ejected from classical novae. Specifically, the strengths of key proton-unbound resonances in Si26, that govern the rate of the Al25(p,γ) reaction under explosive astrophysical conditions, remain unsettled. Here, we present a detailed spectroscopy study of the Si26 mirror nucleus Mg26. We have measured the lifetime of the 3+, 6.125-MeV state in Mg26 to be 19(3)fs and provide compelling evidence for the existence of a 1- state in the T=1,A=26 system, indicating a previously unaccounted for=1 resonance in the Al25(p,γ) reaction. Using the presently measured lifetime, together with the assumption that the likely 1- state corresponds to a resonance in the Al25+p system at 435.7(53) keV, we find considerable differences in the Al25(p,γ) reaction rate compared to previous works. Based on current nova models, we estimate that classical novae may be responsible for up to ≈15% of the observed galactic abundance of Al26., This work was supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract No. DEAC02-06CH11357 and Grants No. DEFG02-94-ER40834, No. DEFG02-97-ER41041, No. DEFG02-97-ER41043, and No. DE-FG02-93ER4077. U.K. personnel were supported by the Science and Technologies Facilities Council (STFC). This work was partially supported by the Spanish MINECO Grant No. AYA2017-86274-P, by the E.U. FEDER funds, and by the AGAUR/Generalitat de Catalunya Grant No. SGR-661/2017. This article benefited from discussions within the “ChETEC” COST Action (Grant No. CA16117). This research used resources of ANL's ATLAS facility, which is a DOE Office of Science User facility.

Published
2021

41. New constraints on the Al25(p,γ) reaction and its influence on the flux of cosmic γ rays from classical nova explosions

Author

Canete, L., Lotay, G., Christian, G., Doherty, D. T., Catford, W. N., Hallam, S., Seweryniak, D., Albers, H. M., Almaraz-Calderon, S., Bennett, E. A., Carpenter, M. P., Chiara, C. J., Greene, J. P., Hoffman, C. R., Janssens, R. V. F., José, J., Kankainen, A., Lauritsen, T., Matta, A., Moukaddam, M., Ota, S., Saastamoinen, A., Wilkinson, R., and Zhu, S.

Subjects
astrofysiikka, gammasäteily, ydinfysiikka, kosminen säteily, novat
Abstract

The astrophysical 25Al(p,γ)26Si reaction represents one of the key remaining uncertainties in accurately modeling the abundance of radiogenic 26Al ejected from classical novae. Specifically, the strengths of key proton-unbound resonances in 26Si, that govern the rate of the 25Al(p,γ) reaction under explosive astrophysical conditions, remain unsettled. Here, we present a detailed spectroscopy study of the 26Si mirror nucleus 26Mg. We have measured the lifetime of the 3+, 6.125-MeV state in 26Mg to be 19(3)fs and provide compelling evidence for the existence of a 1− state in the T=1,A=26 system, indicating a previously unaccounted for ℓ=1 resonance in the 25Al(p,γ) reaction. Using the presently measured lifetime, together with the assumption that the likely 1− state corresponds to a resonance in the 25Al+p system at 435.7(53) keV, we find considerable differences in the 25Al(p,γ) reaction rate compared to previous works. Based on current nova models, we estimate that classical novae may be responsible for up to ≈15% of the observed galactic abundance of 26Al. peerReviewed

Published
2021

43. Half-life measurements in 164,166Dy using γ−γ fast-timing spectroscopy with the ν-Ball spectrometer

Author

Canavan, R. L., Rudigier, M., Regan, P. H., Lebois, M., Wilson, J. N., Jovancevic, N., Söderström, P.-A., Collins, S. M., Thisse, D., Benito, J., Bottoni, S., Brunet, M., Cieplicka-Oryńczak, N., Courtin, S. (Sandrine), Doherty, D. T., Fraile, L. M., Hadyńska-Klęk, K., Häfner, G., Heine, M. (Marcel), Iskra, Ł. W., Karayonchev, V., Kennington, A., Koseoglou, P., Lotay, G., Lorusso, G., Nakhostin, M., Niţă, C. R., Oberstedt, S., Podolyák, Zs., Qi, L., Régis, J.-M., Sánchez-Tembleque, V., Shearman, R., Vedia, V., and Witt, W.

Subjects
Aucun
Published
2020
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44. Level structure of the Tz=−1 nucleus Ar34 and its relevance for nucleosynthesis in ONe novae

Author

Kennington, A. R. L., primary, Lotay, G., additional, Doherty, D. T., additional, Seweryniak, D., additional, Andreoiu, C., additional, Auranen, K., additional, Carpenter, M. P., additional, Catford, W. N., additional, Deibel, C. M., additional, Hadyńska-Klȩk, K., additional, Hallam, S., additional, Hoff, D., additional, Huang, T., additional, Janssens, R. V. F., additional, Jazrawi, S., additional, José, J., additional, Kondev, F. G., additional, Lauritsen, T., additional, Li, J., additional, Rogers, A. M., additional, Saiz, J., additional, Savard, G., additional, Stolze, S., additional, Wilson, G. L., additional, and Zhu, S., additional

Published
2021
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45. Exploiting Isospin Symmetry to Study the Role of Isomers in Stellar Environments

Author

Hallam, S., primary, Lotay, G., additional, Gade, A., additional, Doherty, D. T., additional, Belarge, J., additional, Bender, P. C., additional, Brown, B. A., additional, Browne, J., additional, Catford, W. N., additional, Elman, B., additional, Estradé, A., additional, Hall, M. R., additional, Longfellow, B., additional, Lunderberg, E., additional, Montes, F., additional, Moukaddam, M., additional, O’Malley, P., additional, Ong, W.-J., additional, Schatz, H., additional, Seweryniak, D., additional, Schmidt, K., additional, Timofeyuk, N. K., additional, Weisshaar, D., additional, and Zegers, R. G. T., additional

Published
2021
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46. A High-Resolution Study of the 110Tc → 110Ru → 110Rh → 110Pd Decay Chain with the GRETINA Array

Author

Jazrawi, S., primary, Doherty, D.T., additional, Allmond, J.M., additional, Regan, P.H., additional, Janssens, R.V.F., additional, Korten, W., additional, Zhu, S., additional, Zielińska, M., additional, Radford, D., additional, Ansari, S., additional, Auranen, K., additional, Bucher, B., additional, Carpenter, M.P., additional, Catford, W.N., additional, Hadyńska-Klek, K., additional, Henderson, J., additional, Hendricks, M., additional, Komorowska, M., additional, Kondev, F.G., additional, Lauritsen, T., additional, Li, J., additional, Lotay, G., additional, Napiorkowski, P.J., additional, Padilla-Rodal, E., additional, Pardo, R.C., additional, Rasco, B.C., additional, Reviol, W., additional, Sarantites, D.G., additional, Seweryniak, D., additional, Santiago-Gonzalez, D., additional, Savard, G., additional, Singh, P., additional, Stolze, S.M., additional, Vondrasek, R., additional, Wilson, G., additional, Wu, C.Y., additional, and Wu, J., additional

Published
2020
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47. Reaction Channel selection techniques and γ – γ fast-timing spectroscopy using the ν-Ball Spectrometer

Author

Canavan, R.L., primary, Rudigier, M., additional, Regan, P.H., additional, Lebois, M., additional, Wilson, J.N., additional, Jovancevic, N., additional, Söderström, P.-A., additional, Thisse, D., additional, Benito, J., additional, Bottoni, S., additional, Brunet, M., additional, Cieplicka-Oryńczak, N., additional, Collins, S.M., additional, Courtin, S., additional, Doherty, D.T., additional, Fraile, L.M., additional, Hadyńska-Klęk, K., additional, Heine, M., additional, Iskra, Ł.W., additional, Karayonchev, V., additional, Kennington, A., additional, Koseoglou, P., additional, Lotay, G., additional, Lorusso, G., additional, Nakhostin, M., additional, Niţă, C.R., additional, Oberstedt, S., additional, Podolyák, Zs., additional, Qi, L., additional, Régis, J.-M., additional, Shearman, R., additional, Vedia, V., additional, and Witt, W., additional

Published
2020
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49. Isomeric and β -decay spectroscopy of Ho173,174

Author

Liu, J. J., primary, Lee, J., additional, Watanabe, H., additional, Nishimura, S., additional, Zhang, G. X., additional, Wu, J., additional, Walker, P. M., additional, Regan, P. H., additional, Söderström, P.-A., additional, Kanaoka, H., additional, Korkulu, Z., additional, Lee, P. S., additional, Yagi, A., additional, Dai, A. C., additional, Xu, F. R., additional, Ahn, D. S., additional, Alharbi, T., additional, Baba, H., additional, Browne, F., additional, Bruce, A. M., additional, Carroll, R. J., additional, Chae, K. Y., additional, Dombradi, Zs., additional, Doornenbal, P., additional, Estrade, A., additional, Fukuda, N., additional, Griffin, C., additional, Ideguchi, E., additional, Inabe, N., additional, Isobe, T., additional, Kanaya, S., additional, Kojouharov, I., additional, Kondev, F. G., additional, Kubo, T., additional, Kubono, S., additional, Kurz, N., additional, Kuti, I., additional, Lalkovski, S., additional, Lane, G. J., additional, Lee, C. S., additional, Lee, E. J., additional, Lorusso, G., additional, Lotay, G., additional, Moon, C.-B., additional, Nishizuka, I., additional, Nita, C. R., additional, Odahara, A., additional, Patel, Z., additional, Phong, V. H., additional, Podolyák, Zs., additional, Roberts, O. J., additional, Sakurai, H., additional, Schaffner, H., additional, Shand, C. M., additional, Shimizu, Y., additional, Sumikama, T., additional, Suzuki, H., additional, Takeda, H., additional, Terashima, S., additional, Vajta, Zs., additional, Valiente-Dobón, J. J., additional, and Xu, Z. Y., additional

Published
2020
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50. Search for Nova Presolar Grains: γ -Ray Spectroscopy of Ar34 and its Relevance for the Astrophysical Cl33(p,γ) Reaction

Author

Kennington, A. R. L., primary, Lotay, G., additional, Doherty, D. T., additional, Seweryniak, D., additional, Andreoiu, C., additional, Auranen, K., additional, Carpenter, M. P., additional, Catford, W. N., additional, Deibel, C. M., additional, Hadyńska-Klęk, K., additional, Hallam, S., additional, Hoff, D. E. M., additional, Huang, T., additional, Janssens, R. V. F., additional, Jazrawi, S., additional, José, J., additional, Kondev, F. G., additional, Lauritsen, T., additional, Li, J., additional, Rogers, A. M., additional, Saiz, J., additional, Savard, G., additional, Stolze, S., additional, Wilson, G. L., additional, and Zhu, S., additional

Published
2020
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