Topic: The End of Ionization
Speaker: Maurice Garcia-Sciveres
For the entire history of Particle Physics, particle “counting” detectors have relied on ionization in gasses, liquids, and solids (including promotion of carriers across a semiconductor band gap). LZ is one such detector. Ionization allows a particle interaction of interest to be turned into an electrical signal or a light pulse that can be received by an electronic amplifier or a photodetector. Ionization is a wonderful, natural background suppression mechanism. Particle detectors are blind to any physical process that does not ionize. The rich physics below ionization threshold has always been the concern of Materials Science, not Particle Physics. But what happens when the particle interactions we wish to count are below the ionization threshold for any material (including semiconductors)? Low mass particle dark matter candidates and coherent elastic neutrino nucleus scattering fall in this category. This talk will discuss the development of particle detectors that abandon ionization as the fundamental detection mechanism, with bias towards the TESSERACT collaboration and low mass particle dark matter detection. Surrendering the one most important thing that made particle detectors possible in the first place is not a trivial matter and blurs the boundaries between Particle Physics and Materials Science.
Maurice Garcia-Sciveres is a senior scientist at LBNL focusing on instrumentation development for discovery of new particle interactions at both extremes of energy and intensity. At the high energy/intensity extreme that features hybrid pixel detector technology and pixel readout integrated circuits in particular. He has been a member of the ATLAS experiment since 2000, had a major role in the development of its pixel detector currently in operation, and co-lead the cern.ch/RD53 collaboration after co-founding it in 2013, to deliver the pixel readout integrated circuits (the most complex chips developed for particle physics to date) for the coming upgrades of both the ATLAS and CMS experiments at the Large Hadron Collider. At the low energy/intensity extreme his focus is on technology to extend sensitivity of low mass particle dark matter searches and is a member of the TESSERACT Collaboration. He led the Berkeley/Caltech/Princeton/U.Mass/Yale QuantISED Quest program since 2018, which aims to develop new types of low energy noiseless phonon sensors leveraging QIS advances.
