Download University of Surrey Nuclear Physics Research Group 4 Professors

University of Surrey Nuclear Physics Research Group
Nuclear theory group (2 Professors (Al-Khalili & Tostevin) ; 2 Senior Lecturers
(Stevenson & Barbieri), 1 STFC Rutherford fellow (Rios); 1 Senior Research Fellow
(Timofeyuk). Reaction and structure theory, including intensive computational,
super cluster work. Supported by 1 PDRA.
Nuclear experimentalist (Profs. Catford, Podolyak, Regan* & Walker, STFC
Rutherford Fellow (Lotay*) all work on nuclear structure & nuclear reaction
(astro)physics and instrumentation development. Supported by 2 PDRAs
* joint positions within AIR Division at NPL.
Fundamental research based on synthesis and structure studies of exotic isotopes
and evolution of nuclear structure as function of changing proton and neutron
number & parameters such as angular momentum (spin) and binding energy
(temperature).
Expertise in gamma-ray and charged particle spectroscopy, nuclear data evaluation
and interpretation and ‘big data’ co-incidence analysis.
Supported mainly via STFC consolidated grant (~£2M recently renewed for 2015-19)
Esoteric science…
• How were the elements formed ?
• What do atomic nuclei ‘look like’ ?
• Make the first identification of new isotopes of elements.
Why do this ?
• It’s really interesting and exciting frontline science.
• It tries to answer some of the most fundamental questions.
• It’s challenging and exciting and requires developments of
innovative instrumentation and analysis techniques..
Some Physics Questions from the STFC Nuclear Physics Advisory Panel
• What are the limits of nuclear existence?
• Can atomic nuclei be described in terms of our understanding of the
underlying fundamental interactions?
• How does the ordering of quantum states change in unstable nuclei?
• Are there new forms of structure at the limits of nuclear existence?
• How, and where, were the heavy elements synthesised?
• How do nuclear reactions influence the evolution of massive stars, and
how do they contribute to observed elemental abundances?
Lines of constant A=Z+N are called ‘isobars’.
Most energetically stable nuclei in the middle,
More exotic, unstable nuclei at the edges….
e.g., A=100
‘Nuclei = combinations of protons (Z) and
neutrons (N).
Chart of the Nuclides = a ‘2-D’ periodic table……
<300 of the (Z,N) combinations are radioactively
stable and make up’everyday’ atoms.
~7,000 other combinations are unstable
nuclei…..we will try to study these….
Lots of Surrey-led nuclear physics research currently going on..
The RISING array @ GSI
(105 germanium detectors)
The World’s most powerful
gamma-ray microscope for
the measurement of new
quantum transitions in
radioactive nuclei.
A recent example….
Use of the Surrey-led RISING and Si Active Stopper for the first ID and measurements
in the heaviest Gold, Lead and Bismuth isotopes. Provides world unique data for precision tests
of nuclear structure models & input for explosive nucleosynthesis calculations.
Work at the GSI facility in Darmstadt, Germany. …Part of the NUSTAR (Nuclear Structure,
Astrophysics and Reactions) collaboration which is a major part of the future $1B FAIR
(Facility For Anti-Proton and Ion Research) Centre due to open in 2019.
The Surrey group also uses
gamma-ray spectroscopy
expertise developed in
fundamental research
for measurements of Naturally
Occurring Radioactive
Materials (NORMs) in
environmental samples to
establish baseline
radioactivity levels.
This is important for nuclear waste monitoring and related to the NPL Radioactivity Group’s
work on the production of accurate reference standards for important radionuclides
(such as Neptunium-236) to be used in nuclear-fuel waste assay.
Ongoing development of new instruments for radioactivity measurement…..
The Future: FATIMA for DESPEC
•
FATIMA = FAst TIMing Array = State of the art gamma-ray detection array for
precision measurements of nuclear structure in the most exotic and rare nuclei.
Part of the ~ £8M STFC NUSTAR project grant (runs 2012-16).
– Good energy resolution (better than 3% at 1 MeV).
– Good detection efficiency (between than 5% Full-energy peak at 1 MeV).
– Excellent timing qualities (approaching 100 picoseconds).
•
Use to measure lifetimes of excited nuclear states & provide precision tests of
theories of nuclear structure, uses a fully-digitised Data Acquisition System.
•
Collaboration with NPL (Radioactivity group) through NMO project on ‘Nuclear Data’
(Judge, Jerome, Regan et al.,) on parallel development of NPL-based array for use in
traceable radioactive standards and traceability to the Bq.
Facility for Anti-Proton and Ion Research (FAIR)
$1Bn Pan-European nuclear research centre
Under constructed at the current GSI site, (nr
Darmstadt, Germany), due in ~2019.
Will bring many currently ‘theoretical nuclear
species’ into experimental reach for the first time.