Becca the Physicist
“Welcome to the nerd lab.” – GoGo Tomago (Big Hero 6)
Physics is broken down into several subfields, and I classify as an “experimental nuclear/particle physicist”. We use cutting-edge technologies to observe interactions between particles and matter, and use our observations to better understand the properties of both the matter and the particles! I am fascinated by the hands-down weirdest particle around: the neutrino. Neutrinos are at most one millionth of the mass of an electron and don’t frequently interact with anything. There are billions of neutrinos that pass through your thumbnail every second just from the Sun, but on average, only 1 neutrino will interact within your whole body in your lifetime. And yet, despite their “ghostly” nature, their existence and limited interactions have helped shape the universe!
I work with the COHERENT collaboration and study coherent elastic neutrino-nucleus scattering (CEvNS), a process by which an incoming neutrino hits a target nucleus and causes it to recoil as a whole. Think about throwing a ping-pong ball at a bowling ball; we study the ping-pong ball by investigating the different reactions of the bowling ball! CEvNS will cause the nucleus (our “bowling ball”) to recoil a smidge. When this happens in a scintillator, energy will be released to the material surrounding the nucleus as light, and we can look for this light with a photomultiplier tube. Other types of detectors could look for moving charges or thermal changes to identify CEvNS interactions.
My specific contributions to this collaboration focus on studying the neutrino and neutron fluxes (the number of particles per area per second) incident on our detectors. The neutrino flux might be a little more obviously important: we want to know how many neutrinos will hit our detectors so that we can calculate how many events we should see. The neutron flux is just as mission-critical, because our only experimental signal is a small nuclear recoil – a neutron can cause this too! We need to know how many neutrons will be in our detectors so that we don’t accidentally count them as part of our CEvNS signal.