Current research interests




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



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.