High nuclear polarization of helium-3 at low and high pressure by metastability exchange optical pumping at 1.5 Tesla

Metastability Exchange Optical Pumping of Helium-3 at High Pressures and 1.5 T: Comparison of two Optical Pumping Transitions

At low magnetic field, metastability exchange optical pumping of helium-3 is known to provide high nuclear polarizations for pressures around 1 mbar. In a recent paper, we demonstrated that operating at 1.5 T can significantly improve the results of metastability exchange optical pumping at high pressures. Here, we compare the performances of two different optical pumping lines at 1.5 T, and show that either the achieved nuclear polarization or the production rate can be optimized.

Enhanced Polarization of Low Pressure $^3$He through Metastability-Exchange Optical Pumping at High Field

We report high steady-state nuclear polarization of 1 torr $^3$He gas nuclei via metastability-exchange optical pumping at magnetic fields above 2 T. The introduction of highly polarized $^3$He gas into Brookhaven's Electron Beam Ion Source would enable a new, polarized $^3$He ion source for use at the Relativistic Heavy Ion Collider and a future Electron-Ion Collider facility. By adapting recent developments in high field metastability-exchange optical pumping for higher pressure gas, we have successfully polarized 1 torr $^3$He sealed cells in the EBIS solenoid. Through careful manipulation …

高度极化3He系综中亚稳态交换碰撞中排列张量效应的观测

Observation of alignment tensor effects in metastability-exchange collisions with highly polarized 3He ensembles

通过线性化平均场模型和自由感应衰减测量，实验观测到高度极化3He中亚稳态排列张量引起的弛豫和频移，理论与实验吻合，为高精度磁测和自旋压缩态生成提供应用。

亚稳态交换碰撞引起的基态3He的光致频移与弛豫

Light-induced Frequency Shift and Relaxation of Ground-State 3He via Metastability-Exchange Collisions

本研究发现并验证了3He中亚稳态交换碰撞介导的光与核子自旋相互作用导致的光致频移与弛豫效应，建立了理论模型并探讨了其在低磁场下对磁力计灵敏度的影响，揭示了量子水平光学操控核自旋的潜力。

Magnetic Field Effects on the 1083 nm Atomic Line of Helium. Optical Pumping of Helium and Optical Polarisation Measurement in High Magnetic Field

The structure of the excited $2^{3}$S and $2^{3}$P triplet states of $^{3}$He and $^{4}$He in an applied magnetic field B is studied using different approximations of the atomic Hamiltonian. All optical transitions (line positions and intensities) of the 1083 nm $2^{3}$S-$2^{3}$P transition are computed as a function of B. The effect of metastability exchange collisions between atoms in the ground state and in the $2^{3}$S metastable state is studied, and rate equations are derived, for the populations these states in the general case of an isotopic mixture in an arbitrary field B. It is shown…

A broadband Ytterbium-doped tunable fiber laser for 3He optical pumping at 1083 nm

Large amounts of hyperpolarized 3He gas with high nuclear polarization rates are required for use in neutron spin filters or nuclear magnetic resonance imaging of human lung. Very high efficiency can be obtained by metastability exchange optical pumping using multimode lasers to excite the 23S-23P transition at 1083 nm. Broadband Ytterbium-doped tunable fiber lasers have been designed for that particular application. Different options for the architecture of the fiber oscillator are presented and compared. Emphasis is given to a linear cavity configuration that includes a high reflectivity fib…