OBSERVATION OF MUONIC HF MOLECULE FORMATION WITH TF MU-SR

Negative muon polarization has been measured in pure gaseous Ne (24 at m) and in Ne+H-2 mixtures (24 atm Ne + 1.8 atm H-2, 8 atm H-2 and 16 a tm H-2). The experiment was performed at JINR (Dubna) on a muSR-spectr ometer [1] with 200 G transverse magnetic field at room temperature. I n pure Ne no polarization was observed (a0 = 0.09 +/- 0.1%) while in N e+H-2 mixtures clear precession signals were detected at the free-muon frequency with asymmetries a1.8 = 0.33 +/- 0.13%, a8 = 0.33 +/- 0.14% and a16 = 0.59 +/- 0.09%. The fact that polarization appears in the m uonic HF molecule shows that at the moment of the molecule formation ( t approximately 10(-10) s) the muon is not completely depolarized. The estimate of the reaction constant k = (2.3+/-1.6) x 10(-11) cm3 s-1 a grees with the experimental values obtained by other methods. The resu lt achieved demonstrates that mu-SR-method can be applied for studying fast kinetics processes in the gas phase and in particular for measur ing chemical reaction rates of halogen atoms and ions.