The Defense Advanced Research Projects Agency (DARPA) has issued a Broad Agency Announcement (BAA) for the Quantum Sensing of Neutrinos (QuSeN) program. This program focuses on developing high-sensitivity neutrino detectors to improve the detection of neutrinos from nuclear reactors, nuclear materials, and natural sources. The QuSeN initiative seeks innovative approaches leveraging quantum sensing technologies to address limitations in current detection methods, especially for neutrinos in the energy range of 0.1 to 8 MeV. The research aims to achieve breakthroughs in the design of sensors and absorbers capable of detecting neutrino-matter interactions with unprecedented sensitivity to sub-eV energy transfers.

The primary objective of QuSeN is to overcome two challenges: sensor development and absorber scaling. Sensors must detect energy transfers below 0.5 eV, while absorbers should be scalable to kilogram levels and feature high neutron numbers to maximize detection rates. The detectors are also expected to operate at low temperatures (<0.1 K) and incorporate directional information capabilities to suppress background noise. The program will include proof-of-concept demonstrations during the initial 30-month phase, focusing on achieving signal-to-noise and signal-to-background ratios greater than 1, and phonon detection efficiencies exceeding 50%.

Funding for the program ranges from $1 million to $5 million per award, with multiple awards anticipated. Proposals should address both technical challenges and include a schedule for milestones such as preliminary and critical design reviews, absorber production, and integration phases. DARPA encourages submissions exploring not only the specified quantum sensing approach but also alternate methods that meet program objectives. Eligible entities include U.S. and non-U.S. organizations, with no specific portion of the announcement reserved for small businesses or minority institutions. Federally Funded Research and Development Centers and similar entities must consult with DARPA before submitting proposals.

Proposers are required to submit abstracts by November 25, 2024, for feedback on alignment with program goals, though abstracts are not mandatory. Full proposals are due by February 3, 2025. Submissions must include a detailed technical and management plan, cost breakdowns, risk assessments, and proposed deliverables. DARPA will evaluate proposals based on scientific and technical merit, relevance to national security goals, and cost and schedule realism. Detailed instructions for proposal submission and templates are provided in the BAA.

Evaluation criteria prioritize the feasibility, innovation, and completeness of the technical approach, along with its potential to contribute to DARPA's mission. Proposers must outline risks and mitigation strategies, focusing on optimizing sensitivity to small energy transfers and scaling absorber mass while maintaining detector performance. The program aims to leverage existing research and integrate theory, modeling, and experimental results to achieve its goals.

The program schedule anticipates a start date of July 1, 2025, and includes monthly teleconferences, in-person principal investigator meetings, and milestone-specific reviews. Deliverables include quarterly reports, design review summaries, and a final comprehensive report. DARPA also offers resources such as DARPAConnect and the APEX Accelerators program to support potential applicants in navigating the proposal process and compliance requirements.