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.

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740

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744

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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

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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