Thesis

Development of pulse finding, position reconstruction and intelligent context tagging algorithms for the LUX and LZ Dark Matter direct search experiments.

• Call:

  IDPASC Portugal - PHD Programme 2014

• Academic Year:

  2014 /2015

• Domain:

  Astroparticle Physics

• Supervisor:

  Francisco Neves

• Co-Supervisor:

  Vladimir Solovov

• Institution:

  Universidade de Coimbra

• Host Institution:

  Laboratório de Instrumentação e Física Experimental de Partículas

• Abstract:

  There are a broad range of striking evidences from both astrophysical and cosmological observations that ~80% of the matter in the Universe is made of an unknown form which does not emit or absorb light - the so called Dark Matter (DM). The nature of DM is one of the most important and interesting open scientific questions, capable of attracting broad attention from the public. Moreover, the detection of DM would have a significant impact both on the observational astrophysics and cosmology and fundamental interactions. The answer to the nature of the DM may lie in a generic class of Weakly Interacting Massive Particles (WIMPs). WIMPs, distributed in a halo surrounding our galaxy, would scatter off ordinary baryonic matter in terrestrial detectors. Various experiments are searching for these interactions using different techniques, but so far no clear evidence of a WIMP signals was found. Two of the best limits currently published in the literature (XENON100 and LUX) were obtained with dual-phase (liquid/gas) xenon Time Projection Chambers (TPCs), a technology that was first proven by the ZEPLIN-II experiment. The LIP-Coimbra team joined the LUX collaboration in December 2010, after having worked in the ZEPLIN-II and ZEPLIN-III collaborations since 2005. LIP-Coimbra is also part of the LZ collaboration which is now proposing to design and construct a 7-ton liquid xenon DM TPC. With a fiducial mass of more than 5 tons, the experiment will probe WIMP-nucleon cross sections about 5,000 times better than current results. The PhD student will be integrated in the LIP-Coimbra team which have an accumulated successful experience in the design and management of the Slow Control for DM experiences and also in the design and implementation of both pulse finding and position reconstruction algorithms. The proposed work will be carried out during the LUX 1-year long data taking run and while the LZ project will start to be build. The outline of the main objectives for the PhD student is: • Development of advanced pulse finding algorithms to parameterize the different types of signals acquired in a double-phase (liquid/gas) xenon time projection chamber. The algorithms should be robust and modular to allow its extension to other type of detectors and fields of expertise (e.g. nuclear security and medical imaging); • Development of position reconstruction algorithms and study of their performance. The reconstruction algorithms will use the pulse parameters obtained by the pulse finder but should be generic and modular enough to allow its extension to other type of detectors and fields of expertise (e.g. nuclear security and medical imaging); • Development of heuristic filters to analyze and detect different types of spurious events in the Slow Control (e.g. temperature and pressure extrusions, etc) which may lead to the deterioration of the detector performance and compromise the efficiency of the pulse finding algorithms.