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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? - PowerPoint PPT Presentation
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Nuclear structure
~65% of Uk nuclear physics community is studying nuclear structure
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?
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
Future FAIR facility
SuperFRS
Future facility
Future facility
100 m
GSI todayGSI today
SIS 100/300
UNILAC
ESR
SIS 18
HESR
RESR
NESR
Rare isotope production target
UK is heavily involved in 3 “experiments” within NuSTAR
R3B : Reactions with Relativistic Radioactive Beams
HISPEC: High-resolution in-flight spectroscopy
DESPEC: Decay spectroscopy
One –nucleon knockout reactions measure the spectroscopic factors....how appropriate is a mean-field description for exotic nuclei?
R3B: Reactions with Relativistic Radioactive Beams: an example of
the physics…
n-rich p-rich
RIB from FRS
Light target e.g H2
R3B: Inverse kinematics
“Stripped „ beam carries on
Light particles are emitted here…. UK building a tracker to measure energy and direction
High energy IonsFrom this direction
Liquid Hydrogen TargetGold Foil surround (Not Shown)
3 Layers of Silicon
Vacuum Chamber
Calorimeter
R3B Si Tracker Layout WG leader: R. Lemmon, M. ChartierSTFC Daresbury Laboratory (+ STFC RAL for ASIC)
Universities of Birmingham, Edinburgh, Liverpool, Surrey
Nuclear Structure and Reactions within NUSTAR 8
High energy IonsFrom this direction
Liquid Hydrogen TargetGold Foil surround (Not Shown)
3 Layers of Silicon
Vacuum Chamber
Calorimeter
R3B Si Tracker Layout WG leader: R. Lemmon, M. ChartierSTFC Daresbury Laboratory (+ STFC RAL for ASIC)
Universities of Birmingham, Edinburgh, Liverpool, Surrey
Nuclear Structure and Reactions within NUSTAR 9
More information in Andy Bosto
n’s talk
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?
58
65 r-processpath
rp-processpath
2028
50
82
8
8
20
28
50
82
126
m asses m easured at the FR S-ESR
stable nucle i
nuclides w ith know n m asses
W ill be m easured w ith SU PER -FR S-C R -N ESR
Proton drip-lin
e
HISPEC: High-resolution in-flight spectroscopy: an example of the physics…
In-flight spectroscopy
Produce proton drip-line nuclei.
RIB from FRS
Secondary target Identify products usingLYCCA Lund, York, Cologne calorimeter
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
The Experiment:Slide from S.Milne, L.Scruton, University of York
46V
Look for Tz dependencein B(E2) from first 2+
1 mm 1 mm
Slide from S.Milne, L.Scruton, University of York
Motivation: Isospin Mixing in 46V
Continuing the work at York on mirror pairs and Coulomb energy differences
P.J.Davies et al.,: Physical Review Letters 111 (2013) 072501
-decay
TAS
-b delayed neutron detector
β,n, g-decay of exotic (neutron-rich) nuclei...DESPEC is the most sensitive piece of equipment
Neutron spectrometer MONSTER
g-ray time measurements
DESPEC: Decay spectroscopy, what’s the physics?
g-ray time measurements
Precision tests of wavefunctions by measuring level lifetimes.
RIB from FRS
Stopper
b-decay
or isomeric
decay
g1
g2
• 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/
Active stopper…AIDA...Advanced Implantation Detector Array
Design by University of Liverpool and STFC Daresbury Laboratory
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)
EURICA @ Riken12 RISING clusters 18 LaBr3(Ce) detectors
BigRIPS separator at RIBF at RIKEN
Implant into WAS3ABI - 5 DSSD’swith 2 plastic scintillators
PID plot for 102Y setting, 5 x 105 102Y implants in 2.5 hours
102Y
b correlation time set at 5 t1/2
Cluster spectrum scaled by a factor of 0.06
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
Motivation here is shape evolution towards more neutron rich
Calculated using Grodzin’s formula
Frequency (MHz)
102
101
100
99
98
96
94
93
92
95
97
Cheal et al., Phys.Letts B645 (2007) 133
Static deformation only
b rms=
0.43b rm
s=0.0
Ytrrium (Z=39) shapes measured with lasers
IGISOL IV
Slide from P.Campbell
First on-line laser spectroscopy experiment
104MoIGISOL 3July 2008
104MoIGISOL 4April 2013
107MoIGISOL 4April 2013 • First “commissioning run”
• Already seeing improvements• 107Mo now measured
Slide from P.Campbell
(p,f) 100 μA on 30 g/cm250kW 25MeV photon
Slide from P.Campbell
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
Multiparticle spin trap 19- isomer
Isomeric states (from fragmentation)
208Hg,209TlN. Aldahan et al., PRC80, 061302(R) (2009).
Isomeric stateRISING: isomeric decays
S. Steer et al., Phys. Rev. C 84 (2011) 044313
■
■
*
A. Gottardo et al.PRL109(2012)162502210Hg:PLB 725 (2013)292
M.Reed et al., PRL 105 (2010) 172501, PRC 86 (2012) 054321 (ESR storage ring)
■ ■
■
* *
Slide from Zs.Podolyak
In box: E(4+)/E(2+) ratio
Pb
π νf7/2 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
1.9
1.4 1.4
Core-excited states around 208Pb
Slide from Zs.Podolyak
Isomeric states (from fragmentation)
208Hg,209TlN. Aldahan et al., PRC80, 061302(R) (2009).
Isomeric stateRISING: isomeric decays
S. Steer et al., Phys. Rev. C 84 (2011) 044313
■
■
*
A. Gottardo et al.PRL109(2012)162502210Hg:PLB 725 (2013)292
M.Reed et al., PRL 105 (2010) 172501, PRC 86 (2012) 054321 (ESR storage ring)
■ ■
■
* *
Slide from Zs.Podolyak
GSI accelerator complex
UNILAC
ES
RF
RS
SIS
9Be target
Experimental Storage Ring (ESR)Slide from P.M.Walker
10-s
econ
d sn
apsh
ots
197Au fragmentation
A = 184, q = 72+
2.5 MeV
bare(single ions)
Reed et al., Phys. Rev. Lett. 105 (2010) 172501
0
tim
e (m
inut
es)
20
10
m2 g Ta 0e 1e
2.5 MeV
Hf
frequency
Stored ions: high-K isomers in n-rich 184Hf
Schottky mass spectrometry● first observation of m2 isomer● long-lived β-decaying isomer
T1/2 ≈ 12 min
Slide from P.M.Walker
Spectroscopy Data
Slide from R.-D.Herzberg
Internal Conversion
Slide from R.-D.Herzberg
Overview
Slide from R.-D.Herzberg
SAGE campaigns
1st Campaign (2012)• 251-Md• 253-No• 255-Lr
• 186-Hg• 152-Sm
2nd Campaign (now)
254-No 249-Md
186-Pb 179-Au 222-Th
Slide from R.-D.Herzberg
Identification Problem Z > 112
100
120
114
162
184
108
152
GSI Elements
Z = 107-112Cn
N
Z
DsMt
HsBh
a
b+ EC
SF
b-
Rg
End points fission!
FlLv
IUPAC & IUPAP: direct measurement of atomic number Z !
Z=115
Separation and implantation of fusion-evaporation productsEnergy, position, and time correlation of implantation and decayAlpha-decay chains into known isotopes
JINR H
ot Fusion
48 Ca +
Actinides
Z = 113-11
8
S.G. Nilsson et al.NPA131, 1 (1969)
D. Rudolph, Lund University Föreningen Rydbergs minne, Lund, November 2013
Slide from R.-D.Herzberg
Special thanks to …
The TASISpec / TASCA E115 Collaboration
D. Rudolph, Lund University Föreningen Rydbergs minne, Lund, November 2013
111, 112502 (2013)
ENSARUNILAC
Slide from R.-D.Herzberg
Other highlights:fission mechanism
A Andreyev, M.Huyse and P. Van Duppen: Reviews of Modern Physics 85 (2013) 1541
Beta-delayed fission : ISOLDE/SHIP/GARISFusion fission : JAEA, Tokai, Japan
Other highlights:pear-shaped nuclei
Gaffney, Butler at al.,: Nature 497 (2013) 1541
Used Coulex of radioactive 220Rn and 224Ra beams to measure octupole transition strengths. Conclude stronger octupole deformation in 224Ra than in 220Rn.
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 12C at 22.4 MeV which is interpreted as built ona triangular configuration. Contradicts ab initio calculations which indicate a linear chain of three alpha clusters.
Mentioned specifically becauseit used the Birmingham cyclotron……a UK facility!
On behalf of: