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Nuclear structure

Nuclear structure. ~ 65% of Uk nuclear physics community is studying nuclear structure. Questions we address:. What are the limits of nuclear existence? What is the heaviest element we can make and where does the nuclear dripline lie?

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Nuclear structure

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  1. Nuclear structure ~65% of Uk nuclear physics community is studying nuclear structure

  2. Questions we address: • What are the limits of nuclear existence? What is the heaviest element we can make and where does the nuclear dripline lie? • Do new forms of collective motion occur far from the valley of nuclear stability? • Are there new forms of nuclear matter in very loosely bound nuclear systems? • How does the ordering of quantum states alter in highly dilute or neutron-rich matter? • Do symmetries seen in near-stable nuclei also appear far from stability and do we observe new symmetries? 2007 nuclear physics strategy document

  3. Major investments in time and money at GSI/FAIR University of Jyvaskyla CERN/ISOLDE (to a lesser extent) …will focus on these three but mention other highlights

  4. Future FAIR facility SIS 100/300 Future facility SIS 18 GSI today UNILAC ESR Rare isotope production target HESR Super FRS 100 m RESR NESR

  5. UK is heavily involved in 3 “experiments” within NuSTAR R3B : Reactions with Relativistic Radioactive Beams HISPEC: High-resolution in-flight spectroscopy DESPEC: Decay spectroscopy

  6. R3B: Reactions with Relativistic Radioactive Beams: an example of the physics… n-rich p-rich One –nucleon knockout reactions measure the spectroscopic factors....how appropriate is a mean-field description for exotic nuclei?

  7. R3B: Inverse kinematics Light particles are emitted here…. UK building a tracker to measure energy and direction Light target e.g H2 RIB from FRS “Stripped „ beam carries on

  8. WG leader: R. Lemmon, M. Chartier STFC Daresbury Laboratory (+ STFC RAL for ASIC) Universities of Birmingham, Edinburgh, Liverpool, Surrey R3B Si Tracker Layout Calorimeter Vacuum Chamber 3 Layers of Silicon High energy Ions From this direction Liquid Hydrogen Target Gold Foil surround (Not Shown) Nuclear Structure and Reactions within NUSTAR

  9. More information in Andy Boston’s talk WG leader: R. Lemmon, M. Chartier STFC Daresbury Laboratory (+ STFC RAL for ASIC) Universities of Birmingham, Edinburgh, Liverpool, Surrey R3B Si Tracker Layout Calorimeter Vacuum Chamber 3 Layers of Silicon High energy Ions From this direction Liquid Hydrogen Target Gold Foil surround (Not Shown) Nuclear Structure and Reactions within NUSTAR

  10. HISPEC: High-resolution in-flight spectroscopy: an example of the physics… Spectroscopy of proton drip-line nuclei (a) How does the basic neutron-proton exchange symmetry evolve or break down at the drip-line (b) Can we understand exotic particle decays from proton-rich nuclear matter? (c) What is the structure of nuclei along the crucial rp process path? Proton drip-line

  11. In-flight spectroscopy Identify products using LYCCA Lund, York, Cologne calorimeter Secondary target RIB from FRS Produce proton drip-line nuclei.

  12. The LYCCA Array: Lund-York-Cologne CAlorimeter Secondary Target Start Detector Stop Detector CsI scintillator for residual E 3.6 m Si DSSSD for tracking Si DSSSDs for ΔE and tracking Slide from S.Milne, L.Scruton, University of York

  13. Slide from S.Milne, L.Scruton, University of York The Experiment:

  14. Motivation: Isospin Mixing in 46V 46V Look for Tz dependence in B(E2) from first 2+ 1 mm 1 mm Slide from S.Milne, L.Scruton, University of York

  15. Continuing the work at York on mirror pairs and Coulomb energy differences P.J.Davies et al.,: Physical Review Letters 111 (2013) 072501

  16. -decay DESPEC: Decayspectroscopy, what’s the physics? TAS Neutron spectrometer MONSTER b-delayedneutron detector g-raytime measurements β,n, g-decay of exotic (neutron-rich) nuclei... DESPEC is the most sensitive piece of equipment

  17. g-raytime measurements b-decay or isomeric decay Stopper g1 RIB from FRS g2 Precision tests of wavefunctions by measuring level lifetimes.

  18. Active stopper… AIDA...Advanced Implantation Detector Array • Uses 12 x 8cm x 8cm DSSSD • Compatible with BELEN, MONSTER, TAS….. • Measures position of implant • Fast overload recovery (~ms} • Time stamping http://www2.ph.ed.ac.uk/~td/DSSD/

  19. Design by University of Liverpool and STFC Daresbury Laboratory

  20. ROSPHERE @ Bucharest • 15 HPGe detectors (A/C) were used to detect gamma rays; • 10 x HPGe detectors placed @ 37o • 1 x HPGe detector placed @ 64o • 4 x HPGe detectors placed @ 90o • 11 LaBr3(Ce) detectors were also used: • ø2”x2” @ 90 and 64o (three) (Cylindrical) • ø1.5”x1.5” @ 90 (six) (Cylindrical) • ø1”x1.5” @ 64o (two) (Conical)

  21. EURICA @ Riken • 12 RISING clusters 18 LaBr3(Ce) detectors

  22. BigRIPS separator at RIBF at RIKEN Implant into WAS3ABI - 5 DSSD’s with 2 plastic scintillators

  23. PID plot for 102Y setting, 5 x 105102Y implants in 2.5 hours Cluster spectrum scaled by a factor of 0.06 102Y b correlation time set at 5 t1/2

  24. Time between the beta (measured in the plastic) and the gamma-ray in the LaBr. Measured t1/2 = 2.0 (2) and 2.0 (3) ns, in agreement with literature values

  25. Motivation here is shape evolution towards more neutron rich Calculated using Grodzin’s formula

  26. Ytrrium (Z=39) shapes measured with lasers 102 101 100 99 brms=0.43 98 97 96 95 brms=0.0 94 93 Static deformation only 92 Frequency (MHz) Cheal et al., Phys.Letts B645 (2007) 133

  27. IGISOL IV Slide from P.Campbell

  28. First on-line laser spectroscopy experiment 104Mo IGISOL 3 July 2008 104Mo IGISOL 4 April 2013 107Mo IGISOL 4 April 2013 • First “commissioning run” • Already seeing improvements • 107Mo now measured Slide from P.Campbell

  29. (p,f) 100 μA on 30 g/cm2 50kW 25MeV photon Slide from P.Campbell

  30. PROMPT gammas Isomeric state Isomeric state Delayed Gammas JUROGAM, RITU, GREAT and the TDR. Trigger-less Data Acquisition System D.M. Cullen, Physics with Large Arrays of Novel Scintillators, Dublin, Jan 2014

  31. Multiparticle spin trap 19- isomer

  32. Isomeric states (from fragmentation) ■ ■ * * ■ Gottardo et al. PRL109(2012)162502 210Hg: PLB 725 (2013)292 ■ ■ 208Hg,209Tl N. Aldahan et al., PRC80, 061302(R) (2009). M.Reed et al., PRL 105 (2010) 172501, PRC 86 (2012) 054321 (ESR storage ring) Isomeric state * RISING: isomeric decays S. Steer et al., Phys. Rev. C 84 (2011) 044313 Slide from Zs.Podolyak

  33. πν f7/2 j15/2 i13/2 i11/2 h9/2 g9/2 Z=82 N=126 s1/2 p1/2 d3/2 f5/2 h11/2 p3/2 d5/2 i13/2 Core-excited states around 208Pb Pb 1.4 1.4 1.9 Slide from Zs.Podolyak In box: E(4+)/E(2+) ratio

  34. Isomeric states (from fragmentation) ■ ■ * * ■ Gottardo et al. PRL109(2012)162502 210Hg: PLB 725 (2013)292 ■ ■ 208Hg,209Tl N. Aldahan et al., PRC80, 061302(R) (2009). M.Reed et al., PRL 105 (2010) 172501, PRC 86 (2012) 054321 (ESR storage ring) Isomeric state * RISING: isomeric decays S. Steer et al., Phys. Rev. C 84 (2011) 044313 Slide from Zs.Podolyak

  35. GSI accelerator complex SIS FRS UNILAC ESR 9Be target Experimental Storage Ring (ESR) Slide from P.M.Walker

  36. Stored ions: high-K isomers in n-rich 184Hf 197Au fragmentation ● first observation of m2 isomer ● long-lived β-decaying isomer Schottky mass spectrometry 0e 1e A = 184, q = 72+ m2 g Ta bare (single ions) 0 Hf 2.5 MeV 10-second snapshots time (minutes) 10 2.5 MeV T1/2 ≈ 12 min 20 frequency Reed et al., Phys. Rev. Lett. 105 (2010) 172501 Slide from P.M.Walker

  37. Spectroscopy Data Slide from R.-D.Herzberg

  38. Internal Conversion Slide from R.-D.Herzberg

  39. Overview Slide from R.-D.Herzberg

  40. SAGE campaigns 2nd Campaign (now) • 254-No • 249-Md • 186-Pb • 179-Au • 222-Th 1st Campaign (2012) • 251-Md • 253-No • 255-Lr • 186-Hg • 152-Sm Slide from R.-D.Herzberg

  41. 120 114 108 184 SF 100 a b+ EC 152 162 b- Identification Problem Z > 112 Separation and implantation of fusion-evaporation products Energy, position, and time correlation of implantation and decay Alpha-decay chains into known isotopes JINR Hot Fusion 48Ca + Actinides Z = 113-118 Z Lv Z=115 Fl GSI Elements Z = 107-112 Cn S.G. Nilsson et al. NPA131, 1 (1969) Rg Ds Mt Hs Bh End points fission! IUPAC & IUPAP: direct measurement of atomic number Z ! N Slide from R.-D.Herzberg D. Rudolph, Lund University Föreningen Rydbergs minne, Lund, November 2013

  42. The TASISpec/ TASCAE115 Collaboration 111, 112502 (2013) Special thanks to … UNILAC ENSAR Slide from R.-D.Herzberg D. Rudolph, Lund University Föreningen Rydbergs minne, Lund, November 2013

  43. Other highlights:fission mechanism Beta-delayed fission : ISOLDE/SHIP/GARIS Fusion fission : JAEA, Tokai, Japan A Andreyev, M.Huyse and P. Van Duppen: Reviews of Modern Physics 85 (2013) 1541

  44. Other highlights:pear-shaped nuclei Used Coulex of radioactive 220Rn and 224Ra beams to measure octupole transition strengths. Conclude stronger octupole deformation in 224Ra than in 220Rn. Gaffney, Butler at al.,: Nature 497 (2013) 1541

  45. Other highlights: Carbon-12 caught in a triangle Observed a 5- state in 12C at 22.4 MeV which is interpreted as built on a triangular configuration. Contradicts ab initio calculations which indicate a linear chain of three alpha clusters. Mentioned specifically because it used the Birmingham cyclotron… …a UK facility! D.J.Marin-Lambarri et al., : Physical Review Letters 113 (2014) 1541

  46. On behalf of:

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