Spin-Polarized Hydrogen Depolarization Rates at High Hydrogen Halide Pressures: Hyperfine Depolarization via the HY-H...

Area of Science:

• Physical Chemistry
• Chemical Physics
• Quantum Mechanics

Background:

• Understanding spin-polarized atoms is crucial for various quantum phenomena.
• Photodissociation dynamics and subsequent atomic spin behavior require detailed investigation.

Purpose of the Study:

• To measure magnetization quantum beats of spin-polarized hydrogen (SPH) and spin-polarized deuterium (SPD).
• To investigate the pressure-dependent depolarization rates of SPH and SPD following UV photodissociation of HCl, HBr, and DI.
• To explore the influence of inert gases (SF6, N2) on depolarization rates and elucidate the underlying mechanisms.

Main Methods:

• Utilized a pickup coil to measure magnetization quantum beats.
• Studied UV photodissociation of HCl, HBr, and DI across a wide pressure range (5-5000 mbar).
• Analyzed pressure-dependent depolarization rates and the effect of inert gas addition.

Main Results:

• Observed linear pressure-dependent depolarization at low pressures, transitioning to a plateau at higher pressures.
• Found the high-pressure depolarization rate to be proportional to the halogen nuclear electric quadrupole coupling constant.
• Demonstrated that inert gases (SF6, N2) influence the depolarization rate.

Conclusions:

• The observed depolarization phenomena can be explained by a model involving an HY-H intermediate species (Y = Cl, Br, I).
• The study provides insights into spin relaxation mechanisms in photochemically produced atomic species.