Search for diffuse supernova background in Gd based water Cherenkov experiments

I intend to make a vital measurement of the rate and energy of neutrinos that arrive from distant supernovae throughout the
galaxy. The properties of these neutrinos will tell us much about about the wider composition of the universe as well as neutrinos themselves. This measurement will allow us to test the rate of black hole formation in the universe, test our models of supernova and tell us about the origin of heavy elements and metallicity of the galaxies.

This measurement has not been possible before but is now within reach due to a new adaptation to the detection method known as water Cherenkov. This adaptation adds a metal salt to the water which will increase the efficiency of detection of neutrons present with the neutrino interactions. This will allow us to
dramatically reduce the backgrounds of the measurement. However in order to make this final result possible, I will create new detection software, particle identification and calibration systems for use with detectors loaded with this metal salt. I will also develop novel analysis tools and make preliminary measurements to quantify the interactions of neutrinos with the medium. This is a very exciting area in which to undertake such a project, not only because it of its impact in understanding the nature and
structure of our universe, but also because activity in the field of neutrino astronomy is rapidly escalating, with a number of new observations of neutrino sources outside our
solar system in the last year alone. This study could accelerate that growth and allow us to probe new galactic objects. The novel neutron calibration devices that are being studied
could have wider impact in medical physics as well as the 4 new experiments using the detection method which turn on in the next 5 years.
The world leading DAQ and triggering systems developed as part of this project will be implemented on 3 of these 4 detectors, with the most notable being WATCHMAN, a new UK-US initiative to help combat nuclear non proliferation.
I envisage that the fellowship will contribute to the development and operation of these detectors over the next 4 + 3 years through my development of the necessary online (DAQ and triggering) and offline (calibration and analysis) systems. This work will allow a measurement of the diffuse supernova neutrino background to be undertaken and perfected.
I will build a group to undertake the tasks of this project and will continue in an academic position at Warwick to develop the field further post-Fellowship.

There are many forms of impact related to this project and the technology generated within its remit.

The largest of these is the benefit it will bring to the WATCHMAN project, which is designed to monitor nuclear non-proliferation. This US and UK joint initiative is designed to globally protect people from the threat of nuclear weapons by monitoring power stations and the production of the nuclear material. The work proposed in this project will benefit that effort greatly by providing the DAQ and advanced triggering to run the detector as well as calibration systems designed to understand the gadolinium(Gd)-loaded water Cherenkov detection technology, as well as providing the analysis tools to apply to the data to produce the necessary measurements.

The novel advanced DAQ designed for this work will be used internationally in multiple experiments raising the profile of the UK as experts in this field and is entirely open source and publicly hosted. This will apply techniques from the extremely active field of machine learning and will develop new ones to tackle the unique geometrical data sets used in the field. These techniques will find uses in wider image analysis and recognition.

The calibration systems developed for Gd monitoring could have wider economic use in measuring trace metals in water supplies and for other experiments using this detection technique.

Development of the electronics needed to readout the large area picosecond photodetectors (LAPPDs), will have wider impact as many areas such as medicine, industry and security, are interested in these new detectors and an electronics solution for them will be critical.

The analysis results and tools developed to produce them will have an impact on the field of neutrino physics, increasing the capabilities of water Cherenkov detectors to study these particles. Other fields, principally astronomy and astrophysics, will particularly benefit as the results will tell us about the wider structure and behavior of the universe, especially supernova.

Part of this project also contains an outreach aspect which will promote the field and understanding to a wider audience including school children, through the use of VR visualisations and learning experiences to teach concepts. Warwick university has also provided a PhD student for the project and money has been budgeted for conferences and training to generate skills in the UK and distribute them.