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PJ Woods
University of Edinburgh
N
Nuclear Astrophysics in the UK: A profile
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)
238U fission fragments
from Super FRS
N
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…
Neutron star mergers and accretion disks in -ray
bursts promising alternatives.
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
Masses (Sn)
(location of the path)
-decay half-lives
(progenitor abundances,
process speed)
-delayed n-emission
branchings
(final abundances)
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
Fully stripped 96Ru44+ ions
ions injected
@ 100 MeV/u
Reduced to
~10MeV/u
Gas Stripper
Carbon Foil
Stripper
Study of 96Ru(p,γ)97Rh reaction with decelerated beamsusing the ESR storage ring at GSI
Gas jet
Particle detectors
Pioneering new technique on ESR (Heil, Reifarth) – heavy recoils
detected with double-sided silicon strip detector (Edinburgh)
Position distribution of recoiling ions
measured by DSSD
σ(p,γ)= 3.6(5) mb ~10 MeV/uNew 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(,)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
108 20Ne ions@ 50 MeV/u
1013 H2/cm2 gas target
Electron cooler
ESR
8 m
Study of the p(20Ne,2H)19Ne transfer reaction on the ESR heavy ion storage ring @GSI, PJW, Y Litvinov et al.
A few hours of datafrom test run on ESR
DT Doherty, PhD Thesis (2014)
Spokesperson K Blaum (MPIK,Heidelberg)
Deputies R Raabe (Leuven) PJW (Edinburgh)
TSR@ISOLDE project – Injection of Radioactive Ion Beams into ring at MeV/u energies
entire issue of EPJ 207 1-117 (2012)
18
ISOLDE site (west) side
Proposed layout to fit the TSR at the west side:- Installation above the CERN infrastructure-tunnel
24.6m23.3m
3m
ISOL-SRS Project31 proposers:• Prof. Andrei Andreyev University of York• Dr. Marialuisa Aliotta University of Edinburgh• Prof. Jon Billowes University of Manchester• Dr. Andrew Boston University of Liverpool• Prof. Peter Butler (deputy) University of Liverpool• Prof. Wilton Catford University of Surrey• Prof. Bob Chapman University of the West of Scotland • Prof. Swapan Chattopadhyay Cockcroft Institute and Universities of Liverpool, Manchester and Lancaster• *Dr. Bradley Cheal University of Liverpool• *Dr. Thomas Cocolios University of Manchester• Dr. Dave Cullen University of Manchester• Dr. Thomas Davinson University of Edinburgh• *Dr. Kieran Flanagan University of Manchester• Prof. Sean Freeman (deputy) University of Manchester• Dr. David Jenkins University of York• Dr. David Joss University of Liverpool• Dr. Marc Labiche STFC Daresbury Laboratory• Dr Alison Laird University of York• Mr. Ian Lazarus STFC Daresbury Laboratory• Dr. Annika Lohstroh University of Surrey• *Dr. Gavin Lotay University of Surrey• Dr. Alex Murphy University of Edinburgh• Prof. Robert Page University of Liverpool• Dr. Shrikant Pattalwar STFC Daresbury Laboratory• Prof. Paddy Regan University of Surrey/National Physical Laboratory• Dr Marcus Scheck University of the West of Scotland • Prof. John Simpson STFC Daresbury Laboratory• Dr. John Smith University of the West of Scotland• Prof. Phil Walker University of Surrey• Prof Carsten Welch University of Liverpool and Cockcroft Institute• Prof. Phil Woods (Spokesperson) 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
1 m uniform field
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
Double-sided silicon strip detector + read-out
detector
Final state resolution approaching 20 keV
1m uniform field
0 increasing excitation energyAstrophysicall
y Important
Region
150 MeV 26gAl (CD2)n targetIbeam~ 5*108 pps
proton
High resolution d(26gAl,p)27Al study of analog states of 27Si resonances using TUDA Si array @ ISAC II Triumf
G. Lotay, PJW et al.
717
5
9/2
+
729
2
13/2
+
740
2
11/2
+
744
4
13/2
+
766
4
9/2
+
780
6
9/2
+
794
8
11/2
+
804
3
9/2
−
809
7
5/2
+
Exotic reaction since Jπ = 5+ for 26gAl!
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
E-detector
dE-E-detectors
26Al
10B
Neutron beam
Test Setup at GELINA Belgium (IRMM)
Worlds most enriched 26
Al target
owned by IRMM
THE LUNA EXPERIMENT
GAMMA background
Sco
tt e
t al. P
RL
109
(2
01
2)
20
25
01
Di Le
va e
t al.,
PR
C 8
9 (
20
14
) 0
15
80
3
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