Department of Physics

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IGISOL

The exotic nuclei and beams group studies properties of nuclei employing Penning-trap mass spectrometry as well as laser and decay spectroscopy at the IGISOL-4 facility.

Contact persons: , and

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JYFLTRAP - A part of IGISOL system.

The exotic nuclei and beams group, aka the IGISOL group is a part of the Center of Excellence (CoE) of the Academy of Finland. In 2016 the number of major nuclear physics experiments at the Jyväskylä Ion Guide Isotope Separator On-Line (IGISOL) facility was lower than usual; instead, a significant effort was invested into improving the ion beam transmission to and through the JYFLTRAP Penning trap, resulting in record-breaking transmissions of over 30 % from the IGISOL switchyard to the post-trap setup.

In addition to our home laboratory, our research takes place in number of other laboratories, such as the ISOLDE facility in CERN, GANIL and Helmholzzentrum GSI, the location of the future radioactive beam facility FAIR. We are also actively involved in work to support the development of international future facilities EURISOL and aforementioned FAIR, which we have done in close collaboration with HIP, the Helsinki Institute of Physics.

An important form of our international collaboration is also participation in research networks. Recently, our group has benefited from the EU FP7 and Horizon 2020 programs within ENSAR2, CHANDA and nuClock projects. The research at IGISOL is strongly supported by the Academy of Finland with two Academy Research Fellows and an Academy postdoctoral researcher working in the group. The Academy’s FIRI funding has been essential for renewing our research infrastructure.

The research at the IGISOL facility in Jyväskylä since early 1980's until 2010 has been pictured in a laboratory portrait: "Three decades of research at IGISOL", whose articles are published in special issues of European Physical Journal A and Hyperfine Interactions.


  • Technical developments
    • FIRI infrastructure funding »
    • Magneto-optical trapping of Cs atoms»
    • Post-trap decay spectroscopy »
  • Recent research
    • Laser resonance ionization studies of Pu and Th»
    • JYFLTRAP»
    • High-precision mass measurements for IMME at A = 52»
      According to the Isobaric Multiplet Mass Equation (IMME) [1], the masses of Isobaric Analoque States (IAS) in a mass multiplet with a mass number A and isospin T should lie on a parabola: M(A, T, TZ) = a(A, T) + b(A,T)TZ + c(A, T )TZ2 where a, b and c are interpreted as being the scalar, vector and tensor Coulomb energies. High precision mass measurements with Penning traps have offered new possibilities to investigate the validity of the IMME. Masses of 52Co, 52mCo, 52Fe, 52mFe, and 52Mn were determined with JYFLTRAP. 52Co and 52mCo were measured for the first time and were found more bound than predicted. The JYFLTRAP mass values were employed to study IMME for the T = 2 quintet at A = 52. No significant breakdown (beyond the 3σ level) of the quadratic form of the IMME was observed (χ2/n = 2.4). The excitation energies for the isomer and the T = 2 isobaric analogue state in 52Co were determined to be 374(13) keV and 2922(13) keV, respectively. The proton separation energies of 52Co and 53Ni relevant for the astrophysical rapid proton capture process were measured for the first time. [1] S. B. Weinberg, S. and Treiman, Phys. Rev. 116, 465 (1959).
  • Highlights of 2015
    • I-187 Collinear laser spectroscopy of long-lived Pu isotopes »
    • I-199: Quantum-state selective decay spectroscopy: Proton decay branch of 53Com »
    • I-207: Single and double beta decay Q-value of 96Zr »


      The neutrinoless double beta (0νββ) decay is currently of significant interest in nuclear and particle physics. An observation of this decay mode not only gives insight into the nature of the neutrino but also provides information about its absolute mass scale. The critical quantity which enters in theoretical model calculations is the nuclear matrix element [1]. It describes the underlying nuclear physics, and because of its complexity, neither the matrix elements nor the adequacy of the models can be easily assessed.

      We measured the single and double beta decay Q-value of 96Zr. This nucleus has the third largest ββ Q-value, topped only by 48Ca and 150Nd. Furthermore, it is also one of the two nuclides (the other is 48Ca) unstable against single β-decay. If single β-decay is observed in either of these systems, matrix element calculations can be directly tested for double beta decay. Presently, the matrix element is only theoretically determined. Its value has been calculated within the framework of the QRPA model by J. Suhonen’s group.

      Just prior to our work, the 96Zr double beta decay Q-value was measured with Michigan State University's LEBIT trap to be nearly 7 keV higher [2] than in the most recent atomic mass evaluation (AME2012 [3]). Whether this discrepancy would be manifest also in the single beta decay Q-value was still to be confirmed. The measurement imposed an experimental challenge since 96Zr and96Nb are separated by only about 1.8 parts per million in mass. Although challenging, the two were separated with the in-house developed Ramsey cleaning method [4].

      No discrepancy in the single β-decay Q-value was found. The precision of the value was, nevertheless, improved by 20-fold. The 7 keV discrepancy found by the LEBIT group in the ββ Q-value was confirmed.

      This project was done in collaboration with the University of Münster, Calgary, Bratislava and with JYFL J. Suhonen's theory group.

      [1] J. Shone, et al., J. Phys. G: Nucl. Part. Phys. 39 (2012) 124005, doi:10.1088/0954-3899/39/12/124005
      [2] K. Gulyuz, et al., Phys. Rev. C 91, 055501 (2015), doi:10.1103/PhysRevC.91.055501
      [3] G. Audi, et al. , Chinese physics C 36(12) 1157 (2012).
      [4] T. Eronen, et al., Nuclear Instr. and Methods B 266 (2008) 4527–4531, doi:10.1016/j.nimb.2008.05.076.

    • I-200: The first Penning-trap mass measurement of the TZ=-3/2 nucleus 31Cl »
  • Recent publications
    • 19/2017. Caballero-Folch R, et al.: First evidence of multiple β-delayed neutron emission for isotopes with A>100 Acta Physica Polonica B, 48 (3), 529-532 - DOI: 10.5506/APhysPolB.48.529 Submitted on 14 December 2016 , published March 2017
      Authors R. Caballero-Folch, I. Dillmann, J. Agramunt, J.L. Taín, C. Domingo-Pardo, A. Algora, J. Äysto, F. Calvino,L. Canete, G. Cortès, T. Eronen, E. Ganioglu, W. Gelletly, D. Gorelov, V. Guadilla, J. Hakala, A. Jokinen, A. Kankainen, V. Kolhinen, J. Koponen, M. Marta, E. Mendoza, A. Montaner-Pizá, I. Moore, Ch. Nobs, S. Orrigo, H. Penttilä, I. Pohjalainen, J. Reinikainen, A. Riego, S. Rinta-Antila, B. Rubio, P. Salvador-Castineira, V. Simutkin, A. Voss
      Abstract The β-delayed neutron emission probability, Pn, of very neutron-rich nuclei allows us to achieve a better understanding of the nuclear structure above the neutron separation energy, Sn. The emission of neutrons can become the dominant decay process in neutron-rich astrophysical phenomena such as the rapid neutron capture process (r-process). There are around 600 accessible isotopes for which β-delayed one-neutron emission (β1n) is energetically allowed, but the branching ratio has only been determined for about one third of them. β1n decays have been experimentally measured up to the mass A ∼ 150, plus a single measurement of 210Tl. Concerning two-neutron emitters (β2n), ∼ 300 isotopes are accessible and only 24 have been measured so far up to the mass A = 100. In this contribution, we report recent experiments which allowed the measurement of β1n emitters for masses beyond A > 200 and N > 126 and identified the heaviest β2n emitter measured so far, 136Sb.
      Acknowledgements This work is supported by the Spanish Ministerio de Economía y Com- petitividad under grants: CPAN CSD-2007-00042 (Ingenio2010), FPA2008- 04972-C03-03, FPA2008-06419, FPA2010-17142, FPA2011-28770-C03-03, FPA2011-24553, FPA2014-52823-C2-1-P, FPA2014-52823-C2-2-P and the program Severo Ochoa (SEV-2014-0398). It is also supported by the Academy of Finland under Project No. 213503, Nuclear and Accelerator- Based Physics Research at JYFL, and by the European Commission un- der the FP7/EURATOM contract 605203. I.D. and M.M. acknowledge the support of the German Helmholtz Association via the Young Investigators Grant No. VH-NG 627. W.G. acknowledges the support of the UK Science Technology Faculties Council (STFC) under grant No. ST/F012012/1 and the University of Valencia. R.C.F. and I.D. are supported by the National Research Council of Canada (NSERC) Discovery Grants SAPIN-2014-00028 and RGPAS 462257-2014 at TRIUMF.
    • 18/2017. V. Guadilla, et al.: Study of the β decay of fission products with the DTAS detector Acta Physica Polonica B, 48 (3), 517-522 - DOI: 10.5506/APhysPolB.48.517 Submitted on 14 December 2016 , published March 2017
      Authors V. Guadilla, A. Algora, J.L. Tain, J. Agramunt, J. Äystö J.A. Briz, A. Cucoanes, T. Eronen, M. Estienne, M. Fallot, L.M. Fraile, E. Ganioğlu, W. Gelletly, D. Gorelov, J. Hakala, A. Jokinen, D. Jordan, A. Kankainen, V. Kolhinen, J. Koponen, M. Lebois, T. Martinez, M. Monserrate, A. Montaner-Pizá, I. Moore, E. Nácher, S.E.A. Orrigo, H. Penttilä, I. Pohjalainen, A. Porta, J. Reinikainen, M. Reponen, S. Rinta-Antila, B. Rubio, K. Rytkönen, T. Shiba, V. Sonnenschein, A.A. Sonzogni, E. Valencia, V. Vedia, A. Voss, J.N. Wilson, A.-A. Zakari-Issoufou.
      Abstract Total Absorption Spectroscopy measurements of the β decay of 103Mo and 103Tc, important contributors to the decay heat summation calculation in reactors, are reported in this work. The analysis of the experiment, performed at IGISOL with the new DTAS detector, show new β intensity that was not detected in previous measurements with Ge detectors.
      Acknowledgements This work has been supported by the Spanish Ministerio de Economía y Competitividad under the FPA2011-24553, the AIC-A-2011-0696, the FPA 2014-52823-C2-1-P and the SEV-2014-0398 grants, and by the Spanish Min- isterio de Educación under the FPU12/01527 grant.
    • 17/2017. C. Magron, et al.: Precise measurements of half-lives and branching ratios for the β decay of two mirror nuclei, 23Mg and 27Si European Physical Journal A 53: 77 (2017) - DOI: 10.1140/epja/i2017-12271-0 - Submitted on 4 December 2016, accepted 4 April 2017, published 24 April 2017
      Authors C. Magron, A. Alfaurt, B. Blank, L. Daudin, T. Eronen, M. Gerbaux, J. Giovinazzo, D. Gorelov, H. Guérin, J. Hakala, V. Kolhinen, J. Koponen, T. Kurtukian Nieto, I. Moore, H. Penttilä, I. Pohjalainen, J. Reinikainen, M. Reponen, S. Rinta-Antila, M. Roche, A. de Roubin, N. Smirnova, B. Thomas, A. Voss, and L. Xayavong
      Abstract Half-lives and branching ratios for the two mirror β decays of 23Mg and 27Si have been measured at the University of Jyvaskyla with the IGISOL facility. The results obtained, T1/2 = 11.303(3) s and T1/2 = 4.112(2) s for the half-lives of 23Mg and 27Si, respectively, are 7 and 9 times more precise than the averages of previous measurements. The values obtained for the superallowed branching ratios of 23Mg and 27Si are B.R. = 92.18(8)% and B.R. = 99.79(3)%, respectively. The result for 23Mg is three times more precise than the average of the previous measurements, while for 27Si the precision has not been improved, the average of the previous measurements being already very precise. Isospin breaking corrections have been calculated for the two nuclei to determine the corrected Ft value.
      Acknowledgements The authors would like to acknowledge the continuous effort of the whole Jyvaskyla accelerator laboratory staff for ensuring a smooth running of the experiment. This work was supported by the Academy of Finland under the Finnish Centre of Excellence Programme 2012-2017 (Project No. 213503, Nuclear and Accelerator-Based Physics Research at JYFL), by the Conseil Régional d’Aquitaine, and by the European Community FP7 - Capacities - Integrated Infrastructure Initiative - contract ENSAR nO 262010. by the European Union 7th Framework Programme ”Integrated Infrastructure Initiative - Transnational Access”, ENSAR.
    • 16/2017. A. Voss, et al.: High-resolution laser spectroscopy of long-lived plutonium isotopes Physical Review A 95, 032506 (2017) - DOI: 10.1103/PhysRevA.95.032506 - Submitted on 8 December 2016, published 24 March 2017
      Authors A. Voss, V. Sonnenschein, P. Campbell, B. Cheal, T. Kron, I.D. Moore, I. Pohjalainen, S. Raeder, N. Trautmann, K. Wendt
      Abstract Long-lived isotopes of plutonium were studied using two complementary techniques, high-resolution resonance ionisation spectroscopy (HR-RIS) and collinear laser spectroscopy (CLS). Isotope shifts have been measured on the 5f6 7s2 7F0 → 5f5 6d2 7s (J=1) and 5f6 7s2 7F1 → 5f6 7s 7p (J=2) atomic transitions using the HR-RIS method and the hyperfine factors have been extracted for the odd mass nuclei 239,241Pu. Collinear laser spectroscopy was performed on the 5f6 7s 8F 1/2 →J=1/2(27523.61cm−1 ) ionic transition with the hyperfine A factors measured for 239Pu. Changes in mean-squared charge radii have been extracted and show a good agreement with previous non-optical methods, with an uncertainty improvement by approximately one order of magnitude. Plutonium represents the heaviest element studied to date using collinear laser spectroscopy.
      Acknowledgements We thank P. Thörle-Pospiech and J. Runke for preparing the Pu filaments. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 654002, the Academy of Finland under the Finnish Centre of Excellence Programme 2012–2017 (Project No. 251353, Nuclear and Accelerator-Based Physics Research at Jyfl), the Sciences and Technology Facilities Council (Stfc) of the United Kingdom, the Fwo-Vlaanderen (Belgium), Goa/2010/010 (Bof KU Leuven), the Iap Belgian Science Policy (BriX network P7/12) and a Grant from the European Research Council (Erc-2011-Adg-291561-Helios).
    • 15/2017. D. A. Nesterenko, et al.: High-precision mass measurements for the isobaric multiplet mass equation at A = 52 Journal of Physics G: Nuclear and Particle Physics 44 065103 (2017) - DOI: 10.1088/1361-6471/aa67ae - Accepted 20 March 2017, Published 19 April 2017, Available online 20 March 2017
      Authors D.A. Nesterenko, A. Kankainen, L. Canete, M. Block, D. Cox, T. Eronen, C. Fahlander, U. Forsberg, J. Gerl, P. Golubev, J. Hakala, A. Jokinen, V.S. Kolhinen, J. Koponen, N. Lalovic, Ch. Lorenz, I.D. Moore, P. Papadakis, J. Reinikainen, S. Rinta-Antila, D. Rudolph, L.G. Sarmiento, A. Voss, and J. Äystö
      Abstract Masses of 52Co, 52Com, 52Fe, 52Fem, and 52Mn have been measured with the JYFLTRAP double Penning trap mass spectrometer. Of these, 52Co and 52Com have been experimentally determined for the first time and found to be more bound than predicted by extrapolations. The isobaric multiplet mass equation for the T = 2 quintet at A = 52 has been studied employing the new mass values. No significant breakdown (beyond the 3σ level) of the quadratic form of the IMME was observed (χ2/n = 2.4). The cubic coefficient was 6.0(32) keV (χ2/n = 1.1). The excitation energies for the isomer and the T = 2 isobaric analogue state in 52Co have been determined to be 374(13) keV and 2922(13) keV, respectively. The Q value for the proton decay from the 19/2 isomer in 53Co has been determined with an unprecedented precision, Qp = 1558.8(17) keV. The proton separation energies of 52Co and 53Ni relevant for the astrophysical rapid proton capture process have been experimentally determined for the first time.
      Acknowledgements This work has been supported by the Academy of Finland under the Finnish Centre of Excellence Programme 2012 - 2017 (Nuclear and Accelerator Based Physics Research at JYFL) and the Swedish Research Council (VR 2013-4271). A.K., D.N., and L.C. acknowledge support from the Academy of Finland under grant No. 275389.
    • 14/2017. P. V. Bilous, et al.: Internal conversion from excited electronic states of 229Th ions > Editor's Suggestion Physical Review A 95, 032503 (2017) - DOI: 10.1103/PhysRevA.95.032503 Submitted on 22 December 2016, published 13 March 2017
      Authors Pavlo V. Bilous, Georgy A. Kazakov, Iain D. Moore, Thorsten Schumm, and Adriana Palffy
      Abstract The process of internal conversion from excited electronic states is investigated theoretically for the case of the vacuum-ultraviolet nuclear transition of 229Th. Due to the very low transition energy, the 229Th nucleus offers the unique possibility to open the otherwise forbidden internal conversion nuclear decay channel for thorium ions via optical laser excitation of the electronic shell. We show that this feature can be exploited to investigate the isomeric state properties via observation of internal conversion from excited electronic configurations of Th+ and Th2+ ions. A possible experimental realization of the proposed scenario at the nuclear laser spectroscopy facility IGISOL in Jyväskylä, Finland is discussed.
      Acknowledgements The authors gratefully acknowledge funding by the EU FET-Open project 664732.
    • 13/2017. R. P. Groote, et al.: Efficient, high-resolution laser ionization spectroscopy using weak transitions to long-lived excited states Physical Review A 95, 032502 (2017) - DOI: 10.1103/PhysRevA.95.032502 Submitted on 2 December 2016, published 7 March 2017
      Authors R. P. de Groote, M. Verlinde, V. Sonnenschein, K. T. Flanagan, I. Moore, and G. Neyens
      Abstract Laser spectroscopic studies on minute samples of exotic radioactive nuclei require very efficient experimental techniques. In addition, high resolving powers are required to allow extraction of nuclear structure information. Here we demonstrate that by using weak atomic transitions, resonance laser ionization spectroscopy is achieved with the required high efficiency (1%–10%) and precision (linewidths of tens of MHz). We illustrate experimentally and through the use of simulations how the narrow experimental linewidths are achieved and how distorted resonance ionization spectroscopy line shapes can be avoided. The role of the delay of the ionization laser pulse with respect to the excitation laser pulse is crucial: the use of a delayed ionization step permits the best resolving powers and line shapes. A high efficiency is maintained if the intermediate level has a lifetime that is at least of the order of the excitation laser pulse width. A model that describes this process reproduces well the observed features and will help to optimize the conditions for future experiments. The simulation code is available upon request to the authors.
      Acknowledgements We acknowledge the support of the ISOLDE collaboration and technical teams. We are grateful to the COLLAPS collaboration for the use of their cw Ti:sapphire laser system and WaveTrain doubling unit. We thank W. Gins for fruitful discussions and for comparisons to simulations with rate equation codes. Thisworkwas supported by the BriX Research Program No. P7/12 and FWO-Vlaanderen (Belgium) and GOA 15/010 from KU Leuven, ERC Consolidator Grant No. 648381, the Science and Technology Facilities Council Consolidated Grant No. ST/F012071/1 and Continuation Grant No. ST/J000159/1, and the EU Seventh Framework through ENSAR (506065). K.T.F. was supported by STFC Advanced Fellowship Scheme Grant No. ST/G006415/1. This work was also supported by the Academy of Finland under the Center of Excellence Programme 2012–2017 (Nuclear and Accelerator Based Physics Research at JYFL).
    • 12/2017. Oliver S. Kirsebom, et al.: Towards an experimental determination of the transition strength between the ground states of 20F and 20Ne Japanese Physical Society Conference Proceedings 14, 021008 (2017) - DOI: 10.7566/JPSCP.14.021008 Submitted on 19 August 2016, published 28 February 2017
      Authors Oliver S. Kirsebom, Joakim Cederkäll, David G. Jenkins, Pankaj Joshi, Rauno Julin, Anu Kankainen, Tibor Kibédi, Olof Tengblad, and Wladyslaw H. Trzaska
      Proceedings of the 14th International Symposium on Nuclei in the Cosmos (NIC2016)
      Abstract Electron capture on 20Ne is thought to play a crucial role in the final evolution of electron-degenerate ONe stellar cores. Recent calculations suggest that the capture process is dominated by the second-forbidden transition between the ground states of 20Ne and 20F, making an experimental determination of this transition strength highly desirable. To accomplish this task we are refurbishing an intermediate-image magnetic spectrometer capable of focusing 7 MeV electrons, and designing a scintillator detector surrounded by an active cosmic-ray veto shield, which will serve as an energy-dispersive device at the focal plane.
    • 11/2017. Anu Kankainen, et al.: Mass measurements for the rp process Japanese Physical Society Conference Proceedings 14, 011002(2017) - DOI: 10.7566/JPSCP.14.011002Submitted on 18 August 2016, published 28 February 2017
      Authors Anu Kankainen, Laetitia Canete, Tommi Eronen, Dmitry Gorelov, Jani Hakala, Ari Jokinen, Veli S. Kolhinen, Jukka Koponen, Iain D. Moore, Dimitrii Nesterenko, Juuso Reinikainen, Sami Rinta-Antila, and Juha Äystö
      Proceedings of the 14th International Symposium on Nuclei in the Cosmos (NIC2016)
      Abstract One of the key parameters for the reaction network calculations for the rapid proton capture (rp) process, occurring e.g., in type I X-ray bursts, are the masses of the involved nuclei. Nowadays, masses of even rather exotic nuclei can be measured very precisely employing Penning-trap mass spectrometry. With the JYFLTRAP Penning trap at the IGISOL facility, masses of around 100 neutron-deficient nuclei have been determined with a typical precision of a few keV. Most recently, 25Al, 30P, 31Cl and 52Co have been measured. Of these, the precision of the mass-excess value of , 31Cl was improved from 50 to 3.4 keV, and the mass of 52Co was experimentally determined for the first time. The mass of 31Cl is relevant for estimating the waiting-point conditions for , 30S as the 31Cl 30S–30S(p, γ)31Cl equilibrium ratio depends exponentially on the Q value. For 52Co , located at the path towards 56Ni, a deviation from the extrapolated mass value has been revealed. In this contribution, recent JYFLTRAP experiments for the rp process will be discussed.
      Acknowledgements This work has been supported by the Academy of Finland under the Finnish Centre of Excellence Programme 20122017 (Nuclear and Accelerator Based Physics Research at JYFL). A.K., D.N., and L.C. acknowledge support from the Academy of Finland under grant No. 275389.
    • 10/2017. J.L. Tain, et al.: r process (n,γ) rate constrainsts from the γ-emission of neutron unbound states in β decay Japanese Physical Society Conference Proceedings 14, 010607 (2017) - DOI: 10.7566/JPSCP.14.010607 Submitted on 10 September 2016, published 28 February 2017
      Authors J. L. Tain, V. Guadilla, E. Valencia, A. Algora, A.-A. Zakari-Issoufou, S. Rice, J. Agramunt, J. Äystö, L. Batist, M. Bowry, J. A. Briz, V. M. Bui, R. Caballero-Folch, D. Cano-Ott, A. Cucoanes, V.-V. Elomaa, T. Eronen, E. Estevez, M. Estienne, M. Fallot, G. F. Farrelly, L. M. Fraile, E. Ganioglu, A. R. Garcia, W. Gelletly, B. Gomez-Hornillos, D. Gorelov, V. Gorlychev, J. Hakala, A. Jokinen, M. D. Jordan, A. Kankainen, V. S. Kolhinen, F. G. Kondev, J. Koponen, M. Lebois, T. Mart´ınez, P. Mason, E. Mendoza, M. Monserrate, A. Montaner-Piz´ a, I. Moore, E. Nacher, S. Orrigo, H. Penttilä, Zs. Podoly´ak, I. Pohjalainen, A. Porta, P. Regan, J. Reinikainen, M. Reponen, S. Rinta-Antila, J. Rissanen, B. Rubio, K. Rytkönen, T. Shiba, V. Sonnenschein, A. A. Sonzogni, V. Vedia, A. Voss, J.N. Wilson
      Proceedings of the 14th International Symposium on Nuclei in the Cosmos (NIC2016)
      Abstract Total absorption gamma-ray spectroscopy is used to measure accurately the intensity of γ emission from neutron unbound states populated in the β-decay of delayed neutron emitters. From the comparison of this intensity with the intensity of neutron emission a constraint on the (n,γ) cross sectionforhighlyunstableneutron-richnucleicanbededuced.Asurprisinglylarge γ branchingwas observed for a number of isotopes which might indicate the need to increase by a large factor the Hauser-Feshbach (n,γ) cross-section estimates with impact on r process abundance calculations.
    • 9/2017. Laetitia Canete et al.: High-Precision Proton-Capture Q Values for 25Al(p, γ)26Si and 30P(p, γ)31 Japanese Physical Society Conference Proceedings 14, 020503 (2017) - DOI: 10.7566/JPSCP.14.020503 Submitted on 16 August 2016, published 28 February 2017
      Authors Laetitia Canete, Anu Kankainen, Tommi Eronen, Dmitry Gorelov, Jani Hakala, Ari Jokinen, Veli Kolhinen, Jukka Koponen, Iain D. Moore, Juuso Reinikainen, and Sami Rinta-Antila
      Proceedings of the 14th International Symposium on Nuclei in the Cosmos (NIC2016)
      Abstract The masses of astrophysically relevant nuclei, 25Al and 30P, have recently been measured with the JYFLTRAP double Penning trap at the new IGISOL-4 facility at the University of Jyväskylä. Unparalleled precisions of 63 and 64 eV were achieved for the 25Al and 30P masses, respectively. The proton-capture Q values for 25Al(p, γ)26Si and 30P(p, γ)31S were also determined, and their precisions improved by a factor of 4 and 2, respectively, in comparison with AME12. The impact of the more precise values on the resonant proton-capture rate has also been studied.
      Acknowledgements This work has been supported by the EU 7th framework programme Integrating Activities - Transnational Access, project number: 262010 (ENSAR) and by the Academy of Finland under the Finnish Centre of Excellence Programme 2012-2017 (Nuclear and Accelerator Based Physics Research at JYFL). The authors acknowledge the support from the Academy of Finland under project No. 275389.
    • 8/2017. A. Kankainen, et al.: Measurement of key resonance states for the 30P(p, γ)31S reaction rate, and the production of intermediate-mass elements in nova explosions Physics Letters B (2017). - DOI: 10.1016/j.physletb.2017.01.084 Submitted 26 August 2016, accepted 14 January 2017, available online 17 February 2017
      Authors A. Kankainen, P.J. Woods, H. Schatz, T. Poxon-Pearson, D. Doherty, V. Bader, T. Baugher, D. Bazin, B.A. Brown, J. Browne, A. Estrade, A. Gade, J. José, A. Kontos, C. Langer, G. Lotay, Z. Meisel, F. Montes, S. Noji, F. Nunes, G. Perdikakis, J. Pereira, F. Recchia, T. Redpath, M. Scott, D. Seweryniak, J. Stevens, R. Stroberg, D. Weisshaar, K. Wimmer, and R. Zegers
      Abstract We report the first experimental constraints on spectroscopic factors and strengths of key resonances in the 30P(p, γ)31S reaction critical for determining the production of intermediate-mass elements up to Ca in nova ejecta. The 30P(p, γ)31S reaction was studied in inverse kinematics using the GRETINA γ-ray array to measure the angle-integrated cross-sections of states above the proton threshold. In general, negative-parity states are found to be most strongly produced but the absolute values of spectroscopic factors are typically an order of magnitude lower than predicted by the shell-model calculations employing WBP Hamiltonian for the negative-parity states. The results clearly indicate the dominance of a single 3/2 resonance state at 196 keV in the region of nova burning T≈0.10–0.17GK, well within the region of interest for nova nucleosynthesis. Hydrodynamic simulations of nova explosions have been performed to demonstrate the effect on the composition of nova ejecta.
      Acknowledgements The Edinburgh group is grateful for the support from the STFC grants. A.K. acknowledges the support from the Academy of Finland under project No. 275389. J.J. acknowledges sup-port from the Spanish MINECO grant AYA2014-59084-P, the E.U. FEDER funds, and from the AGAUR/Generalitat de Catalunya grant SGR0038/2014. This work was supported by the National Science Foundation under Grants No. PHY-1403906, PHY-1430152 (JINA Center for the Evolution of the Elements) and PHY-1404442, in part by the National Nuclear Security Administration under the Stewardship Science Academic Alliance program through the DOE cooperative agreement DE-FG52-08NA28552, and by the US DOE, Office of Science, Office of Nuclear Physics, under contract number DE-AC02-06CH11357 (ANL). GRETINA was funded by the US DOE Office of Science. Operation of the array at NSCL is supported by the NSF under Cooperative Agreement PHY-1102511(NSCL) and by the DOE under Grant No. DE-AC02-05CH11231(LBNL). We thank L. Riley for providing us the UCGretina GEANT4 code.
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