DiRAC

Galaxy formation re-simulation.

DiRAC is the integrated supercomputing facility for theoretical modelling and HPC-based research in particle physics, nuclear physics, astronomy and cosmology, areas in which the UK is world-leading.

HPC-based modelling remains an essential tool for the exploitation of observational and experimental facilities in astronomy, particle physics and nuclear physics. The investment in new hardware has provided UK particle physicists, nuclear physicists, and astronomers with upgraded HPC technology to address some of the most challenging scientific problems and to test theories and run simulations from the data gathered in experiments.

The DiRAC facility provides a variety of computer architectures, matching machine architecture to the algorithm design and requirements of the research problems to be solved, whilst addressing the STFC scientific challenges. The science facilitated includes:

using supercomputers to enable scientists to calculate what theories of the early universe predict and to test them against observations of the present universe;
undertaking lattice field theory calculations whose primary aim is to increase the predictive power of the Standard Model of elementary particle interactions through numerical simulation of Quantum Chromodynamics;
carrying out state-of-the-art cosmological simulations, including the large-scale distribution of dark matter, the formation of dark matter haloes, the formation and evolution of galaxies and clusters, the physics of the intergalactic medium and the properties of the intracluster gas.

The continued pooling of complementary expertise within DiRAC ensures that the UK remains one of the world-leaders of theoretical modelling in particle physics, nuclear physics, astronomy and cosmology.

Some of the science questions which can be achieved by the DiRAC facilities include the following:

How did the Universe begin and how is it evolving?
How do stars and planetary systems develop and is life unique to our planet?
What are the fundamental constituents and fabric of the Universe and how do they interact?
How can we explore and understand the extremes of the Universe?

Structure and Resources

DiRAC is both an academic-led and academic supervised Facility with an active Project Board and Technical Working Group that ensures that the science goals of the community are solved by the most appropriate technical and algorithmic solution. DiRAC is managed as a single Facility.

Information regarding the services and resources supported by DiRAC can be found on the DiRAC website.

DiRAC Project Board

The DiRAC Project Board is the highest body with the DiRAC management structure and is responsible for the overall direction of the Facility. It puts together the scientific strategy of the Facility and oversees the implementation of this, along with the technical strategy. The Project Board monitors the operations and development, ensuring this is efficient and is responsible for the operations and capital budgets.

Pathways to Impact

In addition to its excellent support for the STFC PPAN (Particle Physics, Astronomy and Nuclear Physics) programme, DiRAC has an outstanding track record of impact delivery in both industrial engagement and innovation activities; along with training and outreach. PhD students use DiRAC resources for their research and develop advanced skills which are transferred to their future careers, and on average trains 50-130 people per year. Many of the projects using DiRAC facilities are actively engaged in public outreach activities which generates significant media and public interest.

A selection of science highlights achieved using DiRAC resources can be found on the DiRAC website, one of which includes the following:

Time-frequency map of two neutron stars spiralling together.
(Credit: DiRAC)

Gravitational Waves 2017: There were a number of significant discoveries during the LIGO-Virgo second observing run where a third binary black hole observation was made in January 2017, followed by another black hole signal in June. During August, a number of further observations were made, including the first observation of gravitational waves from two neutron stars spiralling together. This signal provides the strongest support for Einstein’s general relativity. The theoretical models of binary-black-hole signals were developed with the numerical simulations performed on DiRAC facilities which were an integral part of these gravitational waves measurements. These models have been extended to an approximate model of subdominant harmonics, in readiness for the next observing run in early 2019. This model is now being more precisely tuned to numerical simulations.

How to gain access to DiRAC

Both academic and non-academic users are welcome to use the DiRAC facilities.

Non-academic users

Non-academic users should see the information on the DiRAC website.

Academic Users

Academic users can gain access by applying to the DiRAC Resource Allocation Committee (RAC). The RAC is responsible for the allocation of DiRAC’s resources. The RAC consists of two sub-panels: the Particle Physics and Nuclear Theory Sub-Panel, and the Astronomy and Cosmology Sub-Panel. The sub-panels will assess applications in their respective scientific remits and then the full RAC will recommend the overall allocation of resources across all applications.

The RAC will issue one Call per year inviting applicants to apply for time on DiRAC facilities. The Call guidelines and application forms can be found on the DiRAC website.

The RAC invites the following proposal types:

Short Projects: a self-contained research problem typically lasting 3-6 months, up to a maximum of 12 months.
Thematic Projects: a clearly defined research programme of outstanding scientific merit which requires significant HPC resources over a period longer than 12 months and up to 36 months duration. The proposed research should be world-leading, with the expectation of making step changes in knowledge through the use of DiRAC resources.
Discretionary / Seedcorn Projects: a very small allocation of DiRAC resource (up to 50k resource hours) for very small projects where the researcher is not already a member of an existing short or thematic project; and for scientifically outstanding projects where DiRAC resources could enable a breakthrough to be made but where the impact of the research would be lost if the project were submitted to the annual Call for proposals.
Research Software Engineering Support: a route to apply for more extensive research software engineering support than that automatically given to all projects for code profiling and simple optimisation.

The DiRAC Resource Allocation Committee (RAC) will:

Assess applications for time allocations on the DiRAC facility, taking appropriate account of advice from external reviewers, and make recommendations to the STFC Executive.
Aim to achieve the optimal use of DiRAC resources, taking into account the RAC assessment criteria, STFC strategic priorities and the need to balance resources across the different science areas, and the technical capabilities of the machines.
Advise the STFC Executive on any issues related to DiRAC resource allocation policy and practice.

The DiRAC Resource Allocation Committee is responsible to the STFC Executive and will provide reports to the STFC DiRAC Oversight Committee. Terms of Reference and membership are provided for reference. The DiRAC RAC holds one call per year for projects to gain time on the DiRAC facility.

Links

Last updated: 27 November 2018