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Nuclear Astrophysics in the UK: A profile
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University of Edinburgh
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PJ Woods
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Academics and Research Fellows
Edinburgh University
M. Aliotta, A. Kankainen (Finnish Senior Fellowship), C. Lederer,
(Schroedinger Fellow, Austria), A. Murphy, A Shotter (Emeritus Prof.),
P.J. Woods and L. Zhang (Chinese Scholarship Council Fellow)
York University
C Diaget, B Fulton, A Laird
Surrey University
G. Lotay (Ernest Rutherford Fellow)
This underestimates the actual effort as there is often strong overlap
with nuclear structure eg M Freer (Birmingham), Z Podolyak (Surrey),
A Bruce (Brighton), D Jenkins (York) and nuclear matter, D Watts
(Edinburgh), and astrophysical modelling, R Hirschi (Keele), T
Rauscher (Hertfordshire)
Advanced Implantation Detector Array (AIDA) will be used
for decay studies of r-process nuclei at RIKEN and FAIR
compact high density ASIC electronics instrumentation for multi-channel
Double-sided Silicon Strip Detectors (DSSD)
238
U fission fragments
from Super FRS
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Observations of Elemental Abundances in old metal poor stars:
 Evidence for robust r-process mechanisms
However, for elements below Z ~50 eg Yttrium evidence of
need for a second astrophysical mechanism/site
Sites of the r-process
R-process related to environments with
high-neutron density and high temperature.
Type II supernovae prime suspects…
star mergers and accretion disks in gray bursts promising alternatives.
Neutron
Not enough is known at
present about the physics
to create realistic models
First direct evidence for neutron star merger - kilonova
Hubble space telescope images of afterglow of a
gamma-ray burst, Berger et al. arXiv:1306
Accessing the r-process path at RIKEN and FAIR
b-delayed n-emission
branchings
(final abundances)
b-decay half-lives
(progenitor abundances,
process speed)
Masses (Sn)
(location of the path)
BRIKEN collaboration formed for proposed campaign of
β-n measurements on Big RIPS separator@RIKEN
Also plans to couple to Total Absorption Spectroscopy system
 GT – strength function measurements
Puzzle of the origin of heavy ‘p-nuclei’ – abundant
proton-rich isotopes eg 92Mo and 96Ru
Supernova shock
passing through
O-Ne layers of
progenitor star
Study of 96Ru(p,γ)97Rh reaction with decelerated beams
using the ESR storage ring at GSI
Fully stripped
96Ru44+ ions
Gas Stripper
Carbon Foil
Stripper
ions injected
@ 100 MeV/u
Reduced to
~10MeV/u
Pioneering new technique on ESR (Heil, Reifarth) – heavy recoils
detected with double-sided silicon strip detector (Edinburgh)
Particle detectors
Position distribution of recoiling
ions measured by DSSD
Gas jet
σ(p,γ)= 3.6(5) mb ~10
MeV/u
New DSSD system developed (Edinburgh/GSI/Frankfurt)
for use
in UHV on ESR to measure p-process capture reactions in
Gamow burning energy region – test run 2 weeks ago
 Faster cooling and deceleration for RIB with CRYRING
The 15O(,g)19Ne reaction: the nuclear
trigger of X-ray bursts
Reaction regulates flow between the hot CNO cycles and rp process
 critical for explanation of amplitude and periodicity of bursts
15O(α,γ)19Ne
reaction rate predicted to be dominated by
a single resonance at a CoM energy of 504 keV
Key unknown - α-decay probability from excited state at
4.03 MeV in 19Ne compared to γ-decay, predicted to be ~ 10-4
8m
Study of the p(20Ne,2H)19Ne transfer reaction on the ESR heavy
ion storage ring @GSI, PJW, Y Litvinov et al.
108 20Ne ions
@ 50 MeV/u
ESR
1013 H2/cm2
gas target
Electron
cooler
A few hours of data
from test run on ESR
DT Doherty, PhD Thesis (2014)
TSR@ISOLDE project – Injection of Radioactive Ion Beams
into ring at MeV/u energies
Spokesperson K Blaum (MPIK,Heidelberg)
Deputies R Raabe (Leuven) PJW (Edinburgh)
entire issue of EPJ 207 1-117 (2012)
ISOLDE site (west) side
23.3m
24.6m
3m
Proposed layout to fit the TSR at the west side:
- Installation above the CERN infrastructure-tunnel
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ISOL-SRS Project
31 proposers:
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Prof. Andrei Andreyev
Dr. Marialuisa Aliotta
Prof. Jon Billowes
Dr. Andrew Boston
Prof. Peter Butler (deputy)
Prof. Wilton Catford
Prof. Bob Chapman
Prof. Swapan Chattopadhyay
*Dr. Bradley Cheal
*Dr. Thomas Cocolios
Dr. Dave Cullen
Dr. Thomas Davinson
*Dr. Kieran Flanagan
Prof. Sean Freeman (deputy)
Dr. David Jenkins
Dr. David Joss
Dr. Marc Labiche
Dr Alison Laird
Mr. Ian Lazarus
Dr. Annika Lohstroh
*Dr. Gavin Lotay
Dr. Alex Murphy
Prof. Robert Page
Dr. Shrikant Pattalwar
Prof. Paddy Regan
Dr Marcus Scheck
Prof. John Simpson
Dr. John Smith
Prof. Phil Walker
Prof Carsten Welch
Prof. Phil Woods (Spokesperson)
University of York
University of Edinburgh
University of Manchester
University of Liverpool
University of Liverpool
University of Surrey
University of the West of Scotland
Cockcroft Institute and Universities of Liverpool, Manchester and Lancaster
University of Liverpool
University of Manchester
University of Manchester
University of Edinburgh
University of Manchester
University of Manchester
University of York
University of Liverpool
STFC Daresbury Laboratory
University of York
STFC Daresbury Laboratory
University of Surrey
University of Surrey
University of Edinburgh
University of Liverpool
STFC Daresbury Laboratory
University of Surrey/National Physical Laboratory
University of the West of Scotland
STFC Daresbury Laboratory
University of the West of Scotland
University of Surrey
University of Liverpool and Cockcroft Institute
University of Edinburgh
* 4 STFC Advanced/Rutherford Fellows
In-ring DSSD System for ultra-high resolution (d,p), (p,d)
and (3He,d) transfer studies of astrophysical resonances
UK ISOL-SRS project
For ultra high resolution mode resolution should be entirely limited
by transverse beam emittance
 resolutions approaching 10 keV FWHM attainable
External solenoid spectrometer (Helios-type system) for (d,p)
transfer reaction studies on heavy nuclei outside the ring
eg for studies of shell evolution in near r-process nuclei
detector
1m uniform field
Double-sided silicon
strip detector + read-out
1 m uniform field
Final state resolution approaching 20 keV
High resolution d(26gAl,p)27Al study of analog states of 27Si
resonances using TUDA Si array @ ISAC II Triumf
proton
150 MeV 26gAl  (CD2)n target
Ibeam~ 5*108 pps
G. Lotay, PJW et al.
0  increasing excitation energy
Astrophysically
Important
Region
Exotic reaction since Jπ = 5+ for 26gAl!
8097 5/2+
9/2+
8043 9/2−
7948 11/2+
7806 9/2+
7664 9/2+
7444 13/2+
7402 11/2+
7292 13/2+
7175 9/2+
Key analog states
Galactic abundance distribution of the cosmic
γ-ray emitter 26Al
INTEGRAL satellite telescope - 2.8(8) Msun of 26Al in our galaxy
[R. Diehl, Nature 439 45(2006)]
Supernova Cycle
n_TOF facility (CERN) new EAR_2 beam line
 measurement of key 26Al(n,p) destruction reaction
C Lederer et al.
EAR-2
Test Setup at GELINA Belgium (IRMM)
E-detector
10
Neutron beam
Worlds most enriched
owned by IRMM
B
26
Al
dE-E-detectors
26
Al target
THE LUNA EXPERIMENT
GAMMA background
Scott et al. PRL 109 (2012) 202501
Di Leva et al., PRC 89 (2014) 015803
Gamow peak
energies
Other nuclear astrophysics activities at the following
facilities where, unless stated, role is mainly as users:
In Europe:
France (GANIL - ad hoc silicon reaction chamber set-ups for individual
experiments, Orsay)
Finland (Jyvaskyla)
Germany (Munich, FRANZ in the near future)
Rest of the World:
US (Argonne – FMA Focal plane DSSD system, MSU, Texas A+M –
Tiara development, Notre Dame)
China (Lanzhou)
Nuclear Physics in Astrophysics VII will be jointly hosted by York and
Edinburgh (A Laird, M Aliotta Conf co-Chairs) in York 2015