Electron Bubble Particle Detector

Columbia University's Department of Physics
Nevis Laboratories

Objective

• The objective of the project is to study, design and develop a new "e-Bubble" Particle Detector, using cryogenic liquid (Helium, Hydrogen and Neon) as the detecting medium, for the detection of low-energy particle tracks, such as neutrinos from the Sun and accelerator beams and nuclear reactors. Interest in condensed matter physics is another consideration. The R&D program will allow the determination of the feasibility of constructing a modest-size tracking chamber that in turn would lead to a study for a large solar neutrino detector, which will provide a simultaneous and critical test of stellar evolution theory and of questions in neutrino oscillation. We anticipate that this technology may open up new possibilities for next-generation neutrino detectors, and may also have applications in detecting 'dark matter' particles and at future colliding-beam facilities. The challenge is to obtain the fundamental spatial and energy resolution, to supply a feasible detector structure and readout.

• The project focuses in particular on the interactions of neutrinos scattering off atomic electrons in the detecting medium (a cryogenic liquid), resulting in recoil electrons which can be measured experimentally, aimed at the detection of 1000 solar electron-neutrino scattering events per year in a liquid helium detector with 5-tons sensitive mass in a large volume cylinder, having a diameter of about 3 meters and height of 6.5 meters. The relative subject includes:
  • Physics and Simulation: the kinematics of neutrino-electron scattering, making use of 4-vectors and special relativity to determine the maximum possible energy transfer and the distribution of electron scattering angle
  • Electron Drift in Cryogenic Liquids: the drift velocity, spatial diffusion, ionization charge yield as a function of velocity and electric field, attachment on impurities, recombination and multiple scattering
  • Electronic Detection: the mechanism of electron avalanche gain, charge collection, electrode structure, signal formation and noise measurements
  • Cryogenic and Mechanical Design: the key physics and mechanical parameters, for the design of a liquid helium solar neutrino detector: choice of materials, mechanical supports, pressure vessel, cryostats, vapor-cooling circuits, high and low voltage supplies, thermal and electrical insulation, liquid purification, radioactivity, safety and many others
  • Optical Measurements: imaging tracks of electron bubbles and their transitions by fluorescence or photo-ionization, infrared absorption lines by X-rays or photoelectrons
  • Literature: comprehensive reference library of published materials that could be used both by our research scientists and collaborators