Programme 1: Experimental PDRA
This PDRA will be responsible for the responsibility for the planning setting up and
analysis of the RISING and related experiments during the grant period. Four
experiments using the RISING gamma-ray array plus the DSSSD active stopper have
been approved by the GSI PAC and are expected to run from 2008 onwards. These all
have significant Surrey participation with Podolyak the spokesperson for one of these.
In addition the data analysis from Surrey-led RISING experiments which ran in early
2007 is ongoing . The PDRA will assist with day-to-day supervision of the PhD
students attached to the RISING and later, DESPEC project. Travel to GSI and
(physics) related experiments CERN will be required, plus planning and preparation
meetings. The data analysis, led by Surrey, will also be coordinated between the
European and other UK collaborators and regular meetings will be required. The
PDRA will also be responsible for the maintenance and development of the RISING
Active Stopper. This position is currently funded through the RISING grant to the end
of September 2009 and thus the additional funding for this position would be from
then.
187 words.
Programme 2: Experimental PDRA
The primary duty of this PDRA will be to take responsibility for the setting up,
analysis and dissemination of TIARA and related experiments and results. A series of
experiments at GANIL and TRIUMF is already approved and the major part of the
analysis will fall within the grant period. Further, follow-up experiments in the grant
period are planned. We note that the large task of setting up the array and electronics
for TIARA must be done entirely by our own collaboration, so an experienced
researcher is preferred. In addition, the TIARA array is scheduled for upgraded barrel
detectors and electronics and the PDRA will be expected to contribute to the design,
as well as to the testing and commissioning of these, along with the Experimental
Officer in Surrey. The PDRA will also assist with day-to-day supervision of the PhD
students attached to this project. Surrey’s productive collaboration with CHARISSA
colleagues at Birmingham involves an overlap in personnel, physics interests and
technology with TIARA, and it is appropriate also that part of this PDRA’s time
should be spent collaborating on nucleon-knockout experiments and breakup studies
with these collaborators. The knockout work is conducted at GANIL and the breakup
work at GANIL/SPIRAL plus various stable and radioactive-beam laboratories
(recent/planned: Orsay, ANU, Louvain, Oak Ridge, etc.). Travel to TIARA and
related experiments at GANIL and TRIUMF will be required, plus planning and
preparation meetings. In the UK, analysis will be coordinated between the
collaborators and regular meetings will be required, following our present practice.
251 words
Programme 2: Area (ii): Theoretical PDRA
The knockout reaction methodology is now used worldwide, and quantitatively, based
on work in this area. The PDRA will support advanced analytical and computational
developments in the area, where Surrey has led and driven the theory needed [e.g.
Ha03, To04] to propose and interpret experiments of ever-increasing precision and
exclusivity [e.g. Pa06, Ga04, Fr05, Ga07, Sc07]. Priorities within the grant period are
improved theoretical descriptions of (i) inelastic one- and multi-nucleon removal
(stripping) processes, (ii) two-nucleon elastic break-up events from fast beams, now
needed to allow quantitative study of two-neutron removal events from neutron-rich
systems, and related improved descriptions of nucleon removal to continuum final
states, and (iii) proper implementation and exploitation of the recently-recognised
spectroscopic potential [To07] of momentum distributions of projectile residues
measured following multi-nucleon removal events. Responsiveness to the study of
new, potentially complementary, direct-reaction methodologies and reaction channels,
such as nucleon pickup [Ga07b] and charge-exchange reactions that exploit the most
exotic, fast secondary beams, will be an integral part of the theoretical effort. This
will be made possible by the maintenance of the excellent collaborative linkages with
experimentalists at the NSCL, GSI, RIKEN and GANIL.
189 words
Programme 3: Theory PDRA in High Spin Nuclear Physics
In this research programme, numerical investigations are essential so as to make
progress in understanding the nature of nuclear many-body states at high spin. In
particular, quantum mechanical treatments of dynamical processes, such as wobbling
motion and surface vibrations, require a massive computation within the framework
of the generator coordinate method (GCM). Self-consistency of the mean-fields and
corresponding many-body states, which are used as the basis in the GCM, is also
important, but numerically demanding. Therefore, we need a PDRA to support these
numerical investigations. Developments of computer codes, performing calculations,
and analyses of the numerical results are the main tasks.
101 words
Programme 3: Experimental PDRA in High-Spin Nuclear Physics
This PDRA will be responsible for the responsibility for the planning setting up and
analysis of the AGATA and related experiments during the grant period. We plan
studies as part of the experimental programs at Legnaro and GANIL during the course
of the rolling grant. Podolyak, Regan and Walker are all heavily involved in the
AGATA building project and this PDRA is linked to the request for the physics
exploitation of the device during the first rolling grant period. The PDRA will also
assist with day-to-day supervision of the experimental PhD students attached to the
AGATA and related GAMMASPHERE-based projects. Travel to Argonne, Legnaro
and GANIL-based experiments will be required. The Surrey-led data analysis, from
these experiments will be the responsibility of this PDRA.
138 words.
Programme 4: Experimental PDRA in Detector Innovation
The PDRA position in detector physics will support the nuclear physics activity
through the development of new diamond and CdZnTe radiation detectors. The work
will concentrate on (1) fundamental characterisation of the charge transport properties
of new detector materials (2) fabrication of prototype detector devices using the
group’s detector clean room laboratory, (3) laboratory testing of detector performance
using radioisotopes and test-beam facilities at GSI and GANIL. This research will
further develop the existing industrial collaborations within the group, including work
with Element Six Ltd on diamond detectors, and RAL/STFC and Durham Scientific
Crystals Ltd on CdZnTe detectors. Charge transport studies of detector materials will
utilise the group’s excellent existing electrical and optical characterisation
laboratories, with an emphasis on collaborative work with the various industrial
suppliers of the detector material. For detector fabrication, the PDRA will use the full
range of detector processing facilities in the group’s laboratories, which include wafer
cutting and polishing, photolithography, metal contact deposition, and ion
implantation, which will be used for strip and pixel detector designs. Characterisation
and testing of prototype devices will combine radioisotope source measurements in
the University with beam test measurements at overseas facilities, carried out in
collaboration with other partners at GSI and GANIL.
203 words
PROJECT STUDENTSHIPS
Programme 2: Experimental PhD Studentship #1
The study of transfer reactions with radioactive beams is a highly topical area of
nuclear physics and will offer a rewarding PhD project, with a mixture of detector
development, experimental running and advanced analysis. We are developing new
techniques (combining root analysis and geant simulations) that we wish to maintain
and extend. The simulation techniques allow us to design experiments for new
proposals, as well as to understand in detail the existing experiments. A new student
starting in October 2008 will have an excellent opportunity to work on both new
experiments and new proposals. It is anticipated that the experiment with a 25Ne
beam at TRIUMF will be performed at about this time and that these data will form
the bulk of the thesis work. The student will work closely with the experimental
PDRA assigned to Programme 2. The availability of a project studentship will allow
targeted recruitment and provide manpower for a timely start on the analysis, which is
particularly important for this first planned experiment for our proposed programme
of transfer experiments using ISAC2 at TRIUMF.
178 words
Programme 2: Experimental PhD Studentship #2
A second project studentship for the experimental reactions programme, starting in
October 2009, will ensure that the expertise for these experiments and analysis will be
passed on, in a timely fashion, between students. This will maintain the momentum in
the programme at a time when we will be looking to increase our roles in the new
R3B/EXL and GASPARD projects, giving additional opportunities for experience.
The start of the new student will also correspond to the arrival of a new design of
barrel detector for the TIARA array, and there will be an opportunity to contribute to
the testing and adaptation of the new electronics to these detectors. This will be
assisted by the Surrey PDRA and Experimental Officer. Experimental data from a
transfer reaction with a radioactive beam is anticipated to become available from
either a second experiment at TRIUMF using the Si array with TIGRESS, or else a
new experiment with TIARA at GANIL/SPIRAL.
156 words
Programme 1: Theory PhD Studentship – JAT to provide
A start date of 1.10.09 is requested (following on form project student E. Simpson).
Programme 2 (area 3): Theory PhD Studentship
Quasi-free (p,2p) scattering has proven to be one of the most direct and powerful
ways of investigating both the single-particle properties of a nucleus (its shell
structure) and the effects on the bound nucleons of their environment in the nucleus. It
gives access to single-particle properties such as the separation energies and
momentum distributions of nucleons inside the nucleus, in particular for inner-shell
orbits. In one- and two-nucleon knockout reactions on light nuclear targets such as Be
or C, absorption processes are important and it will be predominantly the valence
nucleons which are removed. This means that nucleons in the inner shell cannot be
probed. In contrast, the (p,2p) reaction in inverse kinematics provides a probe of deep
single particle states.
A project studentship is requested for a clearly defined programme of work in this
area. Initially, the work will involve investigating existing models and codes (such as
THREEDEE [Ch77]), which use a non-relativistic DWIA approach to calculate cross
sections, first with a stable beam such as 12C, then with a radioactive beam. The work
will then extend to the study of mechanisms likely to be important at the high
fragmentation energies planned at GSI/FAIR. A body of knowledge for (p,2p)
reactions on stable targets in normal kinematics exists (e.g. [Ma94]), which explore
dynamical relativistic effects, core recoil effects, finite range effects and medium
modifications to the NN interaction. Such issues will certainly need to be revisited
and addressed when studying exotic nuclei. A start date of 1.10.08 is requested.
243 words
Programme 5 (area 3) Theory PhD Studentship
Development of correlated hyperspherical formalism
There exists a class of nuclei that are obtained by adding one nucleon to a looselybound nucleon-core system, for example 12Be, 9C and 18Ne. For such nuclei, onenucleon overlap integrals that represent single-particle motion can strongly differ
from the standard ones due to the correlations between the two nucleons above the
core. Exact dynamical three-body calculations have confirmed the possibility of
slower radial convergence of the one-nucleon overlaps to their asymptotic form in
core+2N cluster systems due to the strong correlations between the two valence
nucleons. The non-standard behaviour has consequences for the determination of
spectroscopic factors from nucleon removal reactions and predictions of neutron
capture rates on weakly-bound s-wave nuclei at stellar energies. Therefore, theory
must learn to make reliable predictions for non-standard overlaps. The main challenge
for such theory is to treat explicitly the three-body dynamics within a many-body
object. However, even when internal structure of the core is neglected, the model
space, needed to describe the nucleon motion at large distances in coupled-channel
hyperspherical calculations that take into account the core deformation and excitation,
becomes huge. Convergence accelerating methods should be developed in this case.
The present project aims to develop a method of solving the three-body Schrodinger
equation by expanding the thee-body wave function onto a correlated hyperspherical
basis. This will enable us to calculate one-nucleon overlaps with high precision even
when the core has non-zero spin and is deformed and easily excited. A start date of
1.10.08 is requested.
237 words
Programme 5 (area 4) Theory PhD Studentship
Nuclear reaction rates of astrophysical importance
Recently, a relation between mirror decays has been established at the University of
Surrey. It allows one to predict reactions of astrophysical importance using measured
strengths in the tails of nucleon wave functions, defined by asymptotic normalization
coefficients (ANCs), in mirror systems. Experiments that use this idea have been
already performed in China and Canada and new experiments are considered by
experimentalists from the UK, Canada and Russia. One particular area of nuclei that
is of interest for being studied with this technique involves proton-rich middle-mass
nuclei that are synthesized in supernova explosions. Often, these nuclei are deformed
and the question of whether relations between mirror decays in deformed nuclei stay
the same needs to be urgently investigated. The present project will tackle this issue.
It will also study whether these relations are applicable in another class of looselybound nuclei of astrophysical importance: the nuclei that behave as a core plus two
valence nucleons. The project will also deal with analysis of experimental transfer
data to derive ANCs and to use them to predict capture cross sections at stellar
energies. Implications of reaction rates on astrophysical network calculations and
cosmic abundances will be studied as well. A start date of 1.10.09 is requested.
196 words
SUPPORT STAFF
Programmer/physicist
The experimental research programmes at Surrey require the support of a
programmer/physicist. The person will have a PhD in nuclear physics, or a related
subject, and have a demonstrable talent for computing. This person will play an
important role in interfacing the pulse-processing electronics with the data-collection
computers during experiments, and assist with on-line data analysis. Based at Surrey,
he/she will be able to write programs to read and process the complex data sets taken
at a variety of international laboratories, i.e. to adapt the data analysis systems at
Surrey to read a variety of different data formats. This is a job that requires dedicated
effort for the efficient and timely processing of new experimental results. We have
found from experience that such skills are very important, but at present we have no
member of the group to perform the task. Continuity of effort is a key aspect, so we
are requesting the support, shared between the different experimental programmes, to
be on-going through the duration of the research grant. This will enable us to recruit
and retain someone with appropriate skills.
The person will travel to accelerator facilities to assist with setting up and integrating
the different experimental data streams, which could come from as many as four
different detector systems in different formats. Travel funds will be required as for
other experimenters. The person will be strongly involved in research programmes 1,
2 and 3.
237 words
Physicist/experimental officer
In order to fulfil its international commitments and expectations, the Surrey
experimental group requires the support of a physicist/experimental officer. The
person will have a PhD in nuclear physics or a related subject, and have expertise in
the design, development and operation of state-of-the-art radiation detection systems.
The Surrey group has established a track record for detector-systems innovation, such
as with TIARA and RISING, but to maintain and strengthen this activity it is
necessary to have additional support. While we have employed such a person in the
past, appropriate continuity has not been available. Therefore, on-going support over
the grant period is sought. The person will work on research programmes 1 and 2.
He/she will initially be most strongly involved with TIARA upgrading (programme 2)
led by Surrey. The other key aspect is to support NUSTAR exploitation through
RISING upgrading, leading to HISPEC/DESPEC (programmes 1 and 2) where Surrey
physicists are also taking leading roles. Travel funds will be required, as for other
experimentalists, to work at international laboratories, especially for the setting up of
experiments.
176 words