ISOLDE Workshop and Usersmeeting. Wednesday 05 December - Friday 07 December 2018 .CERN ( ISOLDE User Support. PH Departmen - CERN/CH-1211 Geneve 23).   --.https://indico.cern.ch/event/736872/contributions

Ciemny, Aleksandra

Dominik, W.

Fijalkowska, A.

Fraile, L.M.

García Borge, María José

Giska, Amanda

Janas, Z.

Janiak, U.

Kaminski, G.

Korgul, A. B.

Kubiela, Adam

Mazzocchi, Ch.

Miernik, K.

Ovejas, J. D.

Pfutzner, M. L.

Pomorski, Marcin

Sokolowska, Natalia Anna

English

Fraile, Luis M.

Digital.CSIC

ISOLDEWorkshop and Usersmeeting 2018Wednesday 05 December 2018 - Friday 07 December 2018CERNBook of AbstractsISOLDE Workshop and Users meeting 2018 / Book of Abstractsinformation about SP energies for νp3/2, νp1/2, νh9/2 and νf5/2 neutron orbitals relative to theνf7/2 ground state of 133Sn [1-5]. Still, the knowledge about neutron SP states is not complete andthe question of the position of the neutron-unbound νi 13/2 state remains open for investigation [6].Moreover, information about other unbound states, corresponding to neutron-hole configurations,is also limited. The need to revise studies of 133Sn via β decay of 133In and 134In emerges from therecently-reported significant role of γ ray emission from states at excitation energies more than 1MeV above the neutron separation energy [1].Our experimentwas performed at the ISOLDEDecay Station, where excited states in 133Snwere stud-ied via the β decay of 133In and complemented by studies of the βn decay branch of 134In. Isomer-selective ionization using the ISOLDE RILIS ion source enabled the β decays of 133gIn (Iπ=9/2+) and133mIn (Iπ=1/2−) to be studied independently for the first time [7]. Preliminary results on γ decayof unbound states in 133Sn are presented and discussed.[1] V. Vaquero et al., Phys. Rev. Lett. 118, 202502 (2017).[2] J. M. Allmond et al., Phys. Rev. Lett. 112, 172701 (2014).[3] K. L. Jones et al., Phys. Rev. C 84, 034601 (2011).[4] K. L. Jones et al., Nature (London) 465, 454 (2010).[5] P. Hoff et al., Phys. Rev. Lett. 77, 1020 (1996).[6] A. Korgul et al., Phys. Rev. C 91, 027303 (2015).[7] M. Piersa et al., Acta Phys. Pol. B 49, 523 (2018).Poster Session / 14The impact of dielectronic recombination on the charge state dis-tribution at REXEBISHannes Pahl1 ; Niels Killian Noal Bidault2 ; Fredrik John Carl Wenander31 CERN, Heidelberg University2 CERN, INFN & Sapienza University of Rome3 CERNCorresponding Author(s): hannes.pahl@cern.chDielectronic Recombination (DR) is a resonant process that describes the capture of an electron by a(highly charged) ion, occurring at sharply defined collision energies. In an electron beam ion source,where charge breeding is achieved through successive electron impact ionisation, DR transitions canbe selectively driven by adjusting the electron beam energy. The increased recombination rate on aDR resonance can inhibit the breeding into higher charge states and shift the charge state distributionof the extracted ion beam. This study aims to understand the significance of DR for the operationa charge breeder and to learn if this effect can be exploited for a more selective charge breeding.We have performed simulations and measurements using REXEBIS at ISOLDE for the example ofhighly charged potassium ions (12+ to 17+). Here, we present our preliminary results which showa good agreement between the theoretical predictions and the measured charge state distributions.Our results suggest that the relevance of DR depends strongly on the ion species and the electronbeam parameters. We conclude that DR can be of operational interest and potentially serve as adiagnostic mechanism in special cases.Poster Session / 12Searching for β-delayed protons from 11 BeNatalia Anna Sokolowska1 ; Maria Garcia Borge2 ; Aleksandra Ciemny3 ; WojtekDominik1 ; Aleksandra Fijałkowska4; Luis M Fraile5 ; Amanda Giska4 ; Zenon Janas6 ; Łukasz Janiak4 ; Grzegorz Kaminski7 ; Agnieszka Barbara Korgul1; Adam Kubiela4 ; Chiara Mazzocchi1 ; Krzysztof Miernik4 ; Marek Leslaw Pfutzner1 ; Marcin Pomorski4 ; Ovejas8 ;Silvia Vinals Onses9Page 24ISOLDE Workshop and Users meeting 2018 / Book of Abstracts1 University of Warsaw (PL)2 CSIC Madrid3 Faculty of Physics, University of Warsaw, Poland4 Faculty of Physics, University of Warsaw5 Universidad Complutense (ES)6 Warsaw University7 Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141 980 Dubna, Moscow region, Russia8 IEM/CSIC9 Consejo Superior de Investigaciones Cientificas (CSIC) (ES)Corresponding Author(s): natalia.anna.sokolowska@cern.ch11-Be is the neutron - rich nucleus expected to be a β-delayed proton emitter. The (very mall) branch-ing ratio for this exotic decay mode (∼ 10e−6 ) was obtained through indirectobservations based on accelerator mass spectrometry [1, 2] and resulted to be about twoorders of magnitude larger than predicted by theory [3]. The direct measurement of thedelayed proton emission probability and energy spectrum is particulary challenging, gi-ven the small energy window available (∼ 280 keV). The measurement of the βp energyspectrum is important for estimating the Gamow-Teller strength at high excitatiom ener-gies and testing calculations that predict a direct relation between βp and halo structure.Moreover, recently, a new hypothesis, which may explain results of the AMS experiment,appeard. According to it, the neutron may have another decay channel in which unknownparticles are produced in the final state [4, 5].In August 2018 we performed the experiment IS629 at the HIE-ISOLDE facility, se-arching for β-delayed protons from 11-Be. We used the Warsaw Optical Time ProjectionChamber (OTPC) [6]. The OTPC detector is well suited for detecting charged particlesof low energy backgroung-free. The measurement was extremly challenging because of thecombination of very low branching ratio (10e−8 ∼ 10e−6 ), long half-life (T_1/2 = 13.7 s) andlow energy of the protons. It required development of new solutions for the acquisitionsystem and analysis software.The descriptions of the experiment and the status of the data analysis will be presen-ted.[1] K. Riisager, Nucl. Phys. A 925, 112 (2014).[2] K. Riisager et al., Phys. Lett. B 732, 305 (2014).[3] M. J. G. Borge, et al. J. Phys. G, 40, 035109 (2013).[4] B. Fornal and B. Grinstein, Phys. Rev. Lett. 120, 191801 (2018).[5] M. Pfützner, K. Riisager, Phys. Rev. C 97, 042501(R) (2018).[6] M. Pomorski et al., Phys. Rev. C 90, 014311 (2014).Poster Session / 11Isolde VTim Giles11 CERNCorresponding Author(s): tim.giles@cern.chThe Isolde facility was established in 1967 and since then has been rebuilt three times, in 1976, 1983and in 1992. The fourth and current incarnation is 26 years old, and there is now a strong case foranother major upgrade to address increasing demands on the targets, the isotope separators, and theexperimental hall.The existing target areas are well designed and have already been upgraded with new frontends in2010 and 2011. However the scope for further upgrades is limited. For this reason an extension of thetarget area is proposed, with two new target stations alongwith new isotope separators and amodernbeam delivery system. This would modernise and expand Isolde’s capabilities whilst minimisingperturbation of the existing facility.Page 25

Searching for ß-delayed protons from 11 Be

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Searching for ß-delayed protons from 11 Be

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