The U.S. Department of Energy  Office of Science (DOE-SC) Office of Nuclear Physics approved Critical Decision 1 (CD-1: Approve Alternative Selection and Cost Range) for the High Rigidity Spectrometer (HRS) project 16 September. CD-1 is the second step in the DOE’s staged project-approval process.

CD-1 is DOE’s determination that a preferred alternative has been selected (following the analysis of multiple alternatives) and the team is ready to proceed with engineering and design. HRS achieved CD-0 in November 2018, confirming the mission need, such as a scientific goal or a new capability, requiring material investment exists. In April 2020, the DOE-SC Office of Project Assessment conducted a DOE-SC Independent Project Review of the HRS project.

The next steps are:

• CD-2 (Approve Performance Baseline Scope, Cost, and Schedule)
• CD-3 (Approve Start of Construction)
• CD-4 (Project Completion)

HRS will substantially increase FRIB’s scientific reach and productivity in nuclear structure and nuclear astrophysics research, tests of fundamental symmetry, and applications of isotopes. The gains in sensitivity are particularly strong for experiments with the most neutron-rich isotopes that have the highest potential for discovery.

A collaboration of scientists (from 20 U.S. universities; Argonne National Laboratory, Lawrence Berkeley National Laboratory, Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and Oak Ridge National Laboratory; and scientists in the field of rare-isotope research from Europe, Japan, and Canada) developed the scientific case and conceptual design for HRS. Learn more about HRS at hrs.lbl.gov.