Postcard: Rossella Romita at the ALICE experiment at CERN
Published on
Dr Rossella Romita is a postdoctoral researcher in the University of Liverpool’s Department of Physics.
“I work in the Nuclear Physics group at Liverpool that is part of the ALICE experiment.
ALICE (A Large Ion Collider Experiment) is one of the major experiments at CERN, Switzerland, the site most famous for the Large Hadron Collider, the Higgs Boson and the invention of the World Wide Web.
The experiment I work on features 1,200 scientists from all over the world. Together we’re trying to recreate the conditions which occurred microseconds after the Big Bang.
To achieve this we collide heavy ions of lead at high speeds by circling them around the 27km accelerator tunnel at near to the speed of light. This collision creates a plasma at extreme temperatures and in 2012 ALICE recorded the highest temperature ever recorded on Earth of 5.5 trillion kelvin, about 100 of thousands times more than the temperature of the sun.
The purpose of the detector is to find out more about the primordial Universe and the force that keeps the elementary particles (quarks) packed inside protons and neutrons. Normally quarks are bound together by other particles called gluons to form protons and neutrons, and it is not possible to observe them “free”.
However, before matter was formed, the Universe was a hot and dense “soup” of free quarks and gluons. At the LHC we replicate this primordial Universe and the aim of the ALICE experiment is to reveal its properties. Additionally, protons and neutrons are made of three quarks. When added together the weight of three quarks is only one percent of the mass of the proton or neutron that they form, so we’re also testing theories about where the other 99% comes from.
Right now I’m also working on upgrading the detectors that make up ALICE. The inner tracking system is a silicon high-precision detector for tracking the thousands of particles emerging from the collision. We are designing a new Inner Tracking System, having at least three times better resolution (like a 25 giga-pixel camera!), to detect particles that we cannot yet “see” with the current device.
Once the new detector is installed in 2020 we hope to be able to see a lot more detail on this early stage of the universe and find out more about how the mass of matter is formed.”
