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

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Presentation on theme: "Nuclear structure ~65% of Uk nuclear physics community is studying nuclear structure."— Presentation transcript:

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

2 Questions we address: 2007 nuclear physics strategy document 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?

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

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

6 One –nucleon knockout reactions measure the spectroscopic factors....how appropriate is a mean-field description for exotic nuclei? R 3 B: Reactions with Relativistic Radioactive Beams: an example of the physics… n-richp-rich

7 RIB from FRS Light target e.g H 2 R 3 B: Inverse kinematics “Stripped „ beam carries on Light particles are emitted here…. UK building a tracker to measure energy and direction

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

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

10 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 HISPEC: High- resolution in-flight spectroscopy: an example of the physics…

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

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

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

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

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

16  -decay TAS  delayed neutron detector β,n,  -decay of exotic (neutron- rich) nuclei... DESPEC is the most sensitive piece of equipment Neutron spectrometer MONSTER  - ray time measurements DESPEC: Decay spectroscopy, what’s the physics?

17  -ray time measurements Precision tests of wavefunctions by measuring level lifetimes. RIB from FRS Stopper  -decay or isomeric decay 11 22

18 Uses 12 x 8cm x 8cm DSSSD Compatible with BELEN, MONSTER, TAS….. Measures position of implant Fast overload recovery (~  s} Time stamping Active stopper… AIDA...Advanced Implantation Detector Array

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20 Design by University of Liverpool and STFC Daresbury Laboratory

21 Bucharest 15 HPGe detectors (A/C) were used to detect gamma rays; 10 x HPGe detectors 37 o 1 x HPGe detector 64 o 4 x HPGe detectors 90 o 11 LaBr 3 (Ce) detectors were also used: 90 and 64 o (three) (Cylindrical) 90 (six) (Cylindrical) 64 o (two) (Conical)

22 Riken 12 RISING clusters 18 LaBr 3 (Ce) detectors

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

24 PID plot for 102 Y setting, 5 x Y implants in 2.5 hours 102 Y  correlation time set at 5 t 1/2 Cluster spectrum scaled by a factor of 0.06

25 Time between the beta (measured in the plastic) and the gamma-ray in the LaBr. Measured t 1/2 = 2.0 (2) and 2.0 (3) ns, in agreement with literature values

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

27 Frequency (MHz) Cheal et al., Phys.Letts B645 (2007) 133 Static deformation only  rms =0.43  rms =0.0 Ytrrium (Z=39) shapes measured with lasers

28 IGISOL IV Slide from P.Campbell

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

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

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

32 Multiparticle spin trap 19 - isomer

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

34 In box: E(4 + )/E(2 + ) ratio Pb π ν 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/ Core-excited states around 208 Pb Slide from Zs.Podolyak

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

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

37 10-second snapshots 197 Au fragmentation A = 184, q = MeV bare (single ions) Reed et al., Phys. Rev. Lett. 105 (2010) time (minutes) m2 g Ta 0e 1e 2.5 MeV Hf frequency Stored ions: high-K isomers in n-rich 184 Hf Schottky mass spectrometry ● first observation of m2 isomer ● long-lived β-decaying isomer T 1/2 ≈ 12 min Slide from P.M.Walker

38 Spectroscopy Data Slide from R.-D.Herzberg

39 Internal Conversion Slide from R.-D.Herzberg

40 Overview Slide from R.-D.Herzberg

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

42 Identification Problem Z > 112 GSI Elements Z = Cn N Z Ds Mt Hs Bh   + EC SF -- Rg End points fission! Fl Lv IUPAC & IUPAP: direct measurement of atomic number Z ! Z=115 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 48 Ca + Actinides Z = S.G. Nilsson et al. NPA131, 1 (1969) D. Rudolph, Lund University Föreningen Rydbergs minne, Lund, November 2013 Slide from R.-D.Herzberg

43 Special thanks to … The TASISpec / TASCA E115 Collaboration D. Rudolph, Lund University Föreningen Rydbergs minne, Lund, November , (2013) ENSAR UNILAC Slide from R.-D.Herzberg

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

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

46 D.J.Marin-Lambarri et al., : Physical Review Letters 113 (2014) 1541 Other highlights: Carbon-12 caught in a triangle Observed a 5 - state in 12 C 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!

47 On behalf of:


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