Thesis

Cherenkov Light Detection with Solar Panels

• Call:

  IDPASC Portugal - PHD Programme 2015

• Academic Year:

  2015 / 2016

• Domains:

  Experimental Particle Physics | Astroparticle Physics

• Supervisor:

  Pedro Assis

• Co-Supervisor:

  Mário Pimenta

• Institution:

  Instituto Superior Técnico

• Host Institution:

  Laboratório de Instrumentação e Física Experimental de Partículas

• Abstract:

  This thesis proposal focus on building a solar panel-based device which can be used simultaneously for power generation and the detection of the Cherenkov light generated by Extensive Air Showers initiated by high energy Cosmic Rays. When entering the Earth’s Atmosphere, Cosmic Rays interact producing a cascade of relativistic particles. Travelling at a speed greater than the light speed in the air, the charged particles produce a Cherenkov beam in the forward direction. The particles propagate in bunch in a disk-like shape, making the Cherenkov light to build up into an intense and fast light pulse. Several parameters of the shower influences the amount and shape of the light pulse produced. Photovoltaic solar panels are becoming more and more common and are commonly used in Cosmic Ray experiments to power isolated, autonomous stations. Solar cells are n-i-p junctions with high quantum efficiency, covering the spectral range of Cherenkov light and are a candidate to be used as a Cherenkov light detector. In a cosmic ray detector array, each station has to be powered, and it is common that it is equipped with a set of photovoltaic solar panels. This thesis consists basically on theoretical and simulation work to estimate the characteristics of the Cherenkov light pulse and estimate the limits of detectability for different primary energies and geometries. Using this information a laboratory setup will be built capable of simulating these light pulse and also, simultaneously, generate the ambient light level to assess the sensitivity in different environmental conditions. It will be necessary to review the present technologies of solar panels and select and procure panels that are more suitable for the proposed aim. A great effort will be devoted to the development of the electronics system that must be capable to extract the Cherenkov signal from the background, amplify it and treat it. The main problem to solve is the coupling of the solar panel to the downstream electronics. Innovative DAQ systems, based on coincidences, will also be pursued to enhance the signal to noise ratio of the measurement. The developments will be used to make a test setup at LIP’s dark room and the panels will be tested under different light conditions and compared to the computed expectation. After the successful completion of laboatory tests we envisage the creation of a working prototype to be tested in a cosmic ray detection facility, for example in Auger in Argentina or in MAGIC at Canaries Islands. The CR detector will give the trigger to the Solar Panel system and offline data that will then be cross-checked with the data from the solar panels. Using solar panels for Cherenkov light detection would combine power generation and a non-standard detection purpose. Replicable, autonomous and highly performing UV light detectors could be highly interesting for other outdoor, harsh environment applications. It follows unconventional approaches, choosing techniques that are non-standard in air-shower detection and that are of interest for other domains of application.