1. Dark matter searches and related
research
I am currently involved in the dark matter searches using
liquid noble gas and cryogenic detectors:
Since 2013 – LUX-ZEPLIN (LZ) project. I am
working on the assessment of the background and Monte Carlo production for this
7 tonne two-phase xenon dark mater experiment to be
constructed at the Sanford Underground Research Facility in the US (South
Dakota).
Since 2010 – EDELWEISS-II/III, an experiment at
the Modane Underground Laboratory (LSM) running at ~mK temperatures. My prime
responsibility is modelling of background radiations
for these experiments, in particular neutron background, and designing improved
shielding against neutrons.
2006-2013 – EURECA, a proposal for a tonne-scale cryogenic experiment at LSM. I was responsible
for evaluating radiogenic and cosmogenic background
for the experiment with a goal to design passive shielding and active veto
system to ensure EURECA reaches the designed sensitivity to WIMPs.
I have been a member of the UK Dark Matter
Collaboration (UKDMC) for about 10 years and have taken part in several
projects within the UKDMC
programme:
1997-2004 – NAIAD experiment with NaI crystals at the Boulby
Underground Laboratory. I was involved in detector construction, calibration
and operation with prime responsibility for data analysis and interpretation. I
have written computer codes for data analysis and interpretation of the results
in terms of the cross-section (or the upper limits) of WIMP interactions with
matter.
1997-2009 – I was involved in the DRIFT project
for directional dark matter detector mainly through the simulations of background
(in particular neutrons) for DRIFT I, DRIFT II and scale-up experiments,
evaluation of gamma rejection factor and calculation of sensitivity to WIMP
interactions.
1997-2007 – ZEPLIN-I/II experiments with liquid
and two-phase xenon targets. My prime responsibility was the data analysis,
Monte Carlo modelling and interpretation of the
results. I have written several computer codes used by the ZEPLIN
Collaboration.
In parallel with the dark matter programme,
I have been working on a general task of evaluating the background radiation in
underground laboratories for experiments for rare event searches (dark matter,
astrophysical neutrino, double-beta decay).
I have written computer codes and carried out
pioneering simulations of neutrons induced by radioactivity and cosmic-ray muons. I have also
designed and carried out experiments to measure muon
and neutron fluxes at Boulby.
I have been a coordinator of the working group on
background studies set up within the EU Framework 6 programme
ILIAS (2004-2009). The objectives of the group were to perform simulations of
various types of backgrounds relevant to underground experiments, in
particular, to dark matter searches, to assess available Monte Carlo codes, to
investigate the requirements for shielding and active veto systems and to
provide inputs to the designs of future experiments.
2. Neutrino physics and astrophysics
Since 2011 – member of the DUNE (formerly LBNE)
collaboration for a multi-tonne liquid argon
experiment in the US (SURF underground site). I am working on studying the
background that may affect the sensitivity of the experiment to proton decay.
Since 2007 – member of the LAGUNA Collaboration which investigates options to construct a multi-tonne scale experiment for neutrino physics and
astrophysics. My involvement is primarily through my experience in background
simulations, in particular modeling cosmic-ray muons.
1997-2005 – member of the ANTARES Collaboration.
I have developed a special version of muon
propagation code MUSIC for the ANTARES collaboration. It has been included in
the simulation package KM3 used by the collaboration as an event generator to
simulate the detector response to high energy muons and cascades. I have proposed to use stopping
atmospheric muons for energy calibration of large
underwater/under-ice detectors and to check Monte Carlo simulations. I have
developed a code TAUSIC to propagate tau-leptons in the ANTARES detector.
3.
Muon propagation code and simulations of muons
I have written a Monte-Carlo code for the simulation
of muon transport through the rock – MUSIC (MUon SImulation Code). The code
has been first used in the analysis of single and multiple muon
events detected by LVD. It was later modified and improved and is currently used
by many research groups around the world: LVD, ANTARES, SNO, UKDMC, EURECA, KamLAND, LZ and other projects. I am responsible for
maintaining and updating the code and providing the support to users. I have
also written a computer code MUSUN to sample single muons
at various depths underground/underwater according to pre-tabulated muon energy spectra and angular distributions. The package
is relevant to simulations of muon-induced neutrons
as a background for dark matter, reactor and astrophysical neutrino, proton
decay and double-beta decay experiments.
4.
Cosmic-ray muons in
environment and nuclear security
I am involved in two muon radiography/tomography
projects. One of them aims at estimating the sensitivity of the technique to
monitor carbon capture and storage underground and design and build the
prototype detector. Through my expertise with cosmic-ray muons
(measurements and simulations) I am involved in a detector design and
construction work and am leading the Monte Carlo modelling
efforts. The second project involves using cosmic rays to detect illicit
nuclear materials in cargo.