The Electron Ion Collider (EIC) will be the next major facility in Nuclear Physics and LBNL’s Relativistic Nuclear Collisions (RNC) group is playing a leading role in its development. The EIC will be constructed at Brookhaven National Laboratory (BNL) and begin data taking in the 2030s, enabling detailed studies of protons, neutrons and atomic nuclei. Key science questions the EIC will address include: How do the nucleonic properties such as mass and spin emerge from partons and their underlying interactions? How do the quark-gluon interactions create nuclear binding? What are the properties of the dense gluonic matter that exists deep inside heavy nuclei?
While the EIC complex will have two interaction regions with the potential to host two large-scale detectors, the initial scope of the EIC construction project includes only one day-one detector. In December 2021, BNL solicited proposals from collaborations interested in participating in the program and three proposals were received: ECCE, ATHENA, and CORE. The proposals were reviewed by the Detector Proposal Advisory Panel (DPAP) in March and a primary recommendation of the DPAP was that each of these collaborations was too small for the final task and they encouraged all three collaborations to merge into a single “Detector One” collaboration.
LBNL took a major role in the design, optimization, and tracking implementation for the silicon tracking and vertexing system in ATHENA, and in the optimization of the far-forward detector system. It is likely that a derivative of these systems will be used in the new detector. In addition, the DPAP endorsed the re-use of the existing BaBar magnet (1.5 Tesla) and the recently completed sPHENIX hadronic calorimeter as proposed by the ECCE collaboration. Additional detector elements are expected to be designed and optimized according to the experience retained by the three former collaborations.
The RNC group took a major role in developing the ATHENA concept and proposal. Barbara Jacak was a member of the ATHENA steering committee and proposal writing committee, Ernst Sichtermann was chair of the Institutional Board, and John Arrington, Spencer Klein & Ernst were conveners for different detector and physics working groups. Extensive simulations were carried out by Rey Cruz Torres, Shujie Li, Wenqing Fan, and other RNC postdocs, students and staff members. Going forward, RNC will be a major contributor to the final design and construction of Detector One.