Relaxation and recombination in spin-polarized atomic hydrogen

Journal Article · Mon Dec 01 00:00:00 EST 1986 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.34.7670· OSTI ID:7162448

Bell, D A; Hess, H F; Kochanski, G P; Buchman, S; Pollack, L; Xiao, Y M; Kleppner, D; Greytak, T J

We have studied relaxation and recombination processes in compressed, doubly polarized atomic hydrogen at temperatures from 0.13 to 0.60 K and magnetic fields from 3 to 9 T. The gas and surface dipole three-body recombination rate constants at a field of 7.6 T are measured to be, respectively, L/sub g/ = 8.9(8) x 10/sup -39/ cm/sup 6/ s/sup -1/ and L/sub s/ = 1.2(4) x 10/sup -24/ cm/sup 4/ s/sup -1/. They decrease slowly with field and L/sub s/ exhibits no significant angular dependence. The three-body recombination rate due to hyperfine mixing has also been measured. Electronic and nuclear relaxation rates have been measured; the b-c electronic relaxation rate constant in the gas is G/sup b//sup c/ = 1.03(7) x 10/sup -15/ cm/sup 3/ s/sup -1/exp(-E/sub b//sub c//k/sub B/T). The temperature and field dependence of the nuclear relaxation rate in the gas are observed to be in excellent agreement with recent theoretical calculations. Three-body surface recombination-rate measurements using /sup 3/He-/sup 4/He surfaces indicate that as little as one monolayer of /sup 3/He on the liquid /sup 4/He surface appreciably decreases the adsorption energy of atomic hydrogen. Densities achieved include 4.5 x 10/sup 18/ atomsX/sup -3/ at 0.55 K (pure /sup 4/He walls), and 1.4 x 10/sup 18/ atomsX/sup -3/ at 0.19 K (8 at. X /sup 3/: He).

• Research Organization: Department of Physics and Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
• OSTI ID: 7162448
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Vol. 34:11
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
HYDROGEN
RECOMBINATION
RELAXATION
ATOMS
COMPARATIVE EVALUATIONS
COMPRESSION
HELIUM
KINETICS
MAGNETIC FIELDS
POLARIZATION
SPIN
THREE-BODY PROBLEM
ULTRALOW TEMPERATURE
ANGULAR MOMENTUM
ELEMENTS
FLUIDS
GASES
MANY-BODY PROBLEM
NONMETALS
PARTICLE PROPERTIES
RARE GASES
640302* - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory