Medidas de vidas medias de estados excitados en 136Te en EXILL-FATIMA V.Vedia1 , L. M. Fraile1, H. Mach1,+, B. Olaizola1, V. Paziy1, J.M. Udías1, P. Spagnoletti2, G.S. Simpson3, J-M. Régis4, A. Blanc5, A. M. Bruce6, G. de France7, M. Jentschel5, J. Jolie4, W. Korten10, U. Köster5, T. Kröll9, S. Lalkovski11, N. Marginean8, P. Mutti5, P.H. Regan12, 13, N. Saed-Samii4, T. Soldner5, C.A. Ur14 and W. Urban15 1Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa 28040 Madrid, Spain 2School of Engineering, University of the West of Scotland, Paisley, PA1 2BE, United Kingdom 3LPSC, Université Joseph Fourier Grenoble 1, CNRS/IN2P3, 4Institut für Kernphysik der Universität zu Köln, Zülpicher Str 77, D-50937 Köln Germany 5Institut Laue-Langevin, CS 20156, 38042 Grenoble Cedex 9, France 6SCEM, University of Brighton, Lewes Road, Brighton, BN2 4GJ, United Kingdom 7Grand Accélérateur National d’Ions Lourds, Caen, France 8Horia Hulubei NIPNE, 77125 Bucharest, Romania 9Institut für Kernphysik, TU Darmstadt, Schlossgartenstr. 9, 64289 Darmstadt, Germany 10CEA de Saclay, IRFU, 91191 Gif-sur-Yvette, France 11Faculty of Physics, University of Sofia, 1164 Sofia, Bulgaria 12Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom 13National Physical Laboratory, Teddington, Middlesex, TW11 0LW, United Kingdom 14INFN, via Marzolo 8, 35131 Padova, Italy 15 Faculty of Physics, University of Warsaw, ul. Pasteura 5, PL-02-093 Warsaw, Poland mv.vedia@ucm.es XXXV Bienal de Física – Gijón 16 Julio
Motivation 136Te 132Sn 2p 2n 136Te N=84, Z=52 132Sn 78Ni 208Pb Onset of Collectivity Single-particle states Seniority scheme (B(E2)) Theoretical models (SM) Lifetimes B(E2) 136Te N=84, Z=52 XXXV Bienal de Física – Gijón 16 Julio
L. M. Fraile et al., Nucl. Phys. A805, 218 (2008) Previous Results 136Te CoulEx studies from REX-ISOLDE on 138,140,142Xe T. Kröll et al., Eur. Phys. J 150 (2007) Fast-Timing at ISOLDE L. M. Fraile et al., Nucl. Phys. A805, 218 (2008) B(E2; 2+0+) 132Sn region CoulEx studies at Oak Ridge. J.M Allmond et al., PRL 118 (2017) Exp Technique CoulEX b-Decay+ATD B(E2; 2+0+) 208(29) e2fm4 245(50) e2fm4 362(31) e2fm4 Reference D. Radford et al., PRL 88, 222501 (2002) L. M. Fraile et al., Nucl. Phys. A805, 218 (2008) J.M. Allmond et al., PRL 118, 092503 (2017)
L. M. Fraile et al., Nucl. Phys. A805, 218 (2008) Previous Results 136Te CoulEx studies from REX-ISOLDE on 138,140,142Xe T. Kröll et al., Eur. Phys. J 150 (2007) Fast-Timing at ISOLDE L. M. Fraile et al., Nucl. Phys. A805, 218 (2008) B(E2; 2+0+) 132Sn region Lifetimes of higher excited states will provide clarification CoulEx studies at Oak Ridge. J.M Allmond et al., PRL 118 (2017) Exp Technique CoulEX b-Decay+ATD B(E2; 2+0+) 208(29) e2fm4 245(50) e2fm4 362(31) e2fm4 Reference D. Radford et al., PRL 88, 222501 (2002) L. M. Fraile et al., Nucl. Phys. A805, 218 (2008) J.M. Allmond et al., PRL 118, 092503 (2017)
THE EXILL-FATIMA CAMPAIGN AND THE HYBRID SPECTROMER 2013 Experimental Set up THE EXILL-FATIMA CAMPAIGN AND THE HYBRID SPECTROMER 2013 Neutron beam Characteristics First experiment on Nuclear Spectroscopy of Prompt Fission Fragments Nuclear reactor ILL, Grenoble France Cold collimated neutron beam of =1.2cm on 235U and 241Pu targets XXXV Bienal de Física – Gijón 16 Julio
THE EXILL-FATIMA CAMPAIGN AND THE HYBRID SPECTROMER 2013 Experimental Set up THE EXILL-FATIMA CAMPAIGN AND THE HYBRID SPECTROMER 2013 Detectors 8 Ge-Clovers from EXOGAM 8 BGO for Compton suppression 16 LaBr3(Ce) detectors in 2 rings Source 1 2 3 4 5 6 7 8 9. 10 16 15 14 13 11 12 Ge: Good Energy Resolution Spectroscopy Branch selection for timing LaBr3(Ce): TIMING Fast response γ-detectors Start and stop detectors Electronics Analogic (CFD, TAC) CAEN VME digitizers 40 TB of Triggerless data XXXV Bienal de Física – Gijón 16 Julio
System resolution (PRD) Fast-Timing ggg(t) Ge-LaBr3-LaBr3(t) 1 2 3 4 5 6 7 8 9. 10 16 15 14 13 11 12 stop start 1 2 T1/2 TAC ATD : Advanced Time Delayed P(t): Prompt Response System resolution (PRD) D(t): Time Distribution TAC spectrum Sub-nanosecond range Picoseconds sensitive Assuming no background H. Mach et al., NPA 523 (1991)
The Generalized Centroid Difference Method (GCD) PRD J-M. Régis et al., NIM A726 (2013) J-M. Régis et al., 6th Workshop on Nuclear Fission on Neutron rich Nuclei. Chamrousse France Assuming no background!
Preliminary Results
136Te Lifetime 2+ PRD 353 keV Ge 607keV LaBr3(Ce) 353 keV Ge XXXV Bienal de Física – Gijón 16 Julio
136Te Lifetime 2+ t=36 (9) ps B(E2;2+ 0+) = 277 (69) e2fm4 Ge: 353 keV LaBr3(Ce) :607-423 keV t=36 (9) ps START STOP B(E2;2+ 0+) = 277 (69) e2fm4 PRD XXXV Bienal de Física – Gijón 16 Julio
B(E2; 2+0+) in 136Te B(E2; 2+0+) 132Sn region Exp Technique CoulEx studies from REX-ISOLDE on 138,140,142Xe T. Kröll et al., Eur. Phys. J 150 (2007) Fast-Timing at ISOLDE L. M. Fraile et al., Nucl. Phys. A805, 218 (2008) CoulEx studies at Oak Ridge. J.M Allmond et al., PRL 118 (2017) B(E2; 2+0+) 132Sn region GCD and Fission fragments at EXILL-FATIMA. Presemt work Exp Technique CoulEX b-Decay+ATD B(E2; 2+0+) 208(29) e2fm4 245(50) e2fm4 362(31) e2fm4 277(70) e2fm4 Present work
136Te Lifetime 4+ Lifetime of 41+ Ge:660 keV LaBr3(Ce) :353-424 keV START STOP Ge:660 keV LaBr3(Ce) :353-424 keV Background corrections need to be done An in depth study of the background is currently being performed PRD XXXV Bienal de Física – Gijón 16 Julio
Conclusiones We have measure the lifetime of the 21+excited state in 136Te providing a preliminary value of t=36 (9) ps The present value is in good agreement with previous b-decay studies t=43(9) ps Measured B(E2;2+->0+)= 277(69) e2fm4 An in depth study of the background contribution to the time distributions is currently being performed Preliminary measurement of higher lying states XXXV Bienal de Física – Gijón 16 Julio
Thank you for your attention!
THE EXILL-FATIMA CAMPAIGN AND THE HYBRID SPECTROMER 2013 Experimental Set up THE EXILL-FATIMA CAMPAIGN AND THE HYBRID SPECTROMER 2013 Source 1 2 3 4 5 6 7 8 9. 10 16 15 14 13 11 12 Detectors 8 Ge-Clovers from EXOGAM 8 BGO for Compton suppression 16 LaBr3(Ce) detectors in 2 rings. LaBr3(Ce): TIMING Fast response γ-detectors Start and stop detectors LaBr3(Ce) 3.3 % @ 662 keV 1.5 in. 180 ps @ 1332-1173 keV 2.0 in. 210 ps @ 1332-1173 keV J-M Régis et al. NIM A 763 (2014) O. Roberts et al. NIM A 748 (2014) XXXV Bienal de Física – Gijón 16 Julio
2D representation of EXOGAM + FATIMA detectors LaBr3(Ce) 2×1.5 inch or 1.5×1.5 inch HV Dynode (Energy) Source 1 2 3 4 5 6 7 8 9. 10 16 15 14 13 11 12 Hamamatsu R9779 PMT 1400V Anode (Time) 4 segmented CLOVER HPGe crystals 20% photopeak efficiency @1.3MeV BGO crystal LN2 HV Energy The total solid angle covered by the germaniums is about 30% and for LaBr3 about 20% for this system. The efficiency differs a little bit from this numbers.
The Generalized Centroid Difference Method (GCD) J-M. Régis et al., NIM A726 (2013) J-M. Régis et al., NIM A763 (2014)
The Generalized Centroid Difference Method (GCD) PRD J-M. Régis et al., NIM A726 (2013) J-M. Régis et al., 6th Workshop on Nuclear Fission on Neutron rich Nuclei. Chamrousse France
Theoretical calculations Previous Results B(E2; 2+0+) transition rates in 136Te Theoretical calculations B(E2; 2+0+) Reference Method 500 e2fm4 A. Covello in PRL 88, (2002) SM 180 e2fm4 J. Teresaki et al. QRPA 300 e2fm4 N. Shimizu et al. MCSM 290 e2fm4 S. M. Wang et al. a-Cluster 340 e2fm4 B.A. Brown in PRL 118 (2017) 410 e2fm4 A. Gargano in PRL 118 (2017)
136Te Lifetimes XXXV Bienal de Física – Gijón 16 Julio
Outline Motivation Experimental details. Preliminary results for 136Te. Conclusions XXXV Bienal de Física – Gijón 16 Julio