3He Metastability Exchange Optical Pumping at High Magnetic Fields: Double Cell Target Design for CLAS12

Following recent advances in high-field Metastability Exchange Optical Pumping (MEOP) of $^3$He at Jefferson Lab, we are developing a double-cell polarized $^3$He target specifically designed for integration with the CLAS12 spectrometer in Hall B. This future target will combine high polarization performance with cryogenic operation and robust compatibility with the large-acceptance geometry of CLAS12. Inspired by prior successful double-cell designs, our approach separates the optical pumping and target chambers, allowing efficient polarization transfer via gas diffusion while minimizing depolarization in the experimental environment. The system will operate in a high-field solenoid (up to 5 T) and 100 mbar pressure. In this talk, we will present the conceptual design, integration challenges, and path toward realizing a high-field, double-cell $^3$He target system capable of supporting next-generation spin physics experiments at Jefferson Lab.

This work is supported by the U.S. Department of Energy, Office of Nuclear Physics, under grant numbers DE-FG02-94ER40818 awarded to the Massachusetts Institute of Technology and DE-AC05-06OR23177 awarded to Jefferson Lab.