The US Nuclear Science Advisory Committee Long Range Plan 2015 identified the Electron-Ion Collider (EIC) as the highest-priority new nuclear physics project in the United States.
The EIC will be the world’s first collider of polarised electrons with nuclei or polarised protons/light ions and will have a design luminosity of 1033 – 1034 cm-2 s-1, and a centre of mass range of 20 - 140 GeV. It will be a discovery machine for understanding QCD interactions, the theory of the strong interaction between quarks mediated by gluons, and studying the structure and dynamics of matter at high luminosity, high energy and with a wide range of nuclei. In particular, the experiment will be able to address how the proton gets its spin, how hadrons acquire their mass from quarks that are almost massless, how gluons prevent quarks from being observed as free particles and establish whether there are emergent forms of matter made of densely packed gluons.
It will consist of two intersecting accelerators, one producing an intense beam of electrons, the other a high-energy beam of protons or heavier atomic nuclei. As these particles collide, the electrons will scatter off the quarks within the proton or nucleus. Studying the patterns and characteristics of the particles ejected in these scattering interactions will tease out the internal structure and distribution of the quarks and gluons.
The initial design studies have already begun, putting the UK EIC group (Glasgow, Birmingham, Lancaster, York, Liverpool, Brunel, STFC TD and PPD), in the position to become a major partner in the construction phase of the project and to establish scientific leadership in the program.
The EiC Detector 1 vertex detector (SVT) is derived from the ALICE ITS3 65nm technology using wafer-scaled stitched sensors, thinned and bent around the beam pipe. PPD is working with TD at RAL and DL to help characterise their IP blocks and test structures produced as part of the initial ALICE MultiLayer Reticule submission (MLR1) in 2021. These are now under test at DL. In addition, PPD has leveraged its expertise in DC-DC and serial powering from ATLAS to investigate powering options that are radiation hard and use minimal material.