Search

The MEG experiment makes use of one of the world's most intense low energy muon beams, in order to search for the lepton flavour violating process $\mu^{+} \rightarrow {\rm e}^{+} \gamma$. We determined the residual beam polarization at the thin stopping target, by measuring the asymmetry of the angular distribution of Michel decay positrons as a function of energy. The initial muon beam polarization at the production is predicted to be $P_{\mu} = -1$ by the Standard Model (SM) with massless neutrinos. We estimated our residual muon polarization to be $P_{\mu} = -0.85 \pm 0.03 ~ {\rm (stat)} ~ { }^{+ 0.04}_{-0.05} ~ {\rm (syst)}$ at the stopping target, which is consistent with the SM predictions when the depolarizing effects occurring during the muon production, propagation and moderation in the target are taken into account. The knowledge of beam polarization is of fundamental importance in order to model the background of our ${\megsign}$ search induced by the muon radiative decay: $\mu^{+} \rightarrow {\rm e}^{+} \bar{\nu}_{\mu} \nu_{\rm e} \gamma$.

Results are presented of a calculation of the flow around a sphere of a two-phase supersonic jet, discharging into a vacuum. Calculations were performed by the determination method with use of a difference grid constructed on the basis of characteristic ratios [1], The parameters of the unperturbed jet were determined with the two-velocity and two-temperature model of mutually penetrating flows of continuous media (gas and particles) [2, 3] by the network method [4]. In calculating the flow around the sphere, as in [5–7], it was assumed that the particles do not affect the gas flow in the shock layer. An analysis of the effect of particles on gasdynamic parameters in a shock layer was performed in [8].

The authors consider the conditions of extremal intensity of fluorescence on the axis of a cylindrical vessel filled with a solution and placed in an elliptical illuminator. They show that under radial pumping or pumping that is isotropic in a plane perpendicular to the vessel axis the fluorescence on the axis of a cylindrical vessel attains maximum intensity when the optical density (ɛCR) of the vessel is equal to 1.

In the production of bimetal apparatus by facing, it is necessary to provide a facing metal (cladding layer) the corrosion resistance of which is similar to the corrosion resistance of the electrode metal in the original condition. However, in all of the known methods of facing including manual, electric arc, mechanized wire, or 0.7-0.8 mm thick strip, the depth of fusion of the base metal is 2-6 mm, which leads to significan t participation of the base metal in the faced layer and, consequent!y, to a reduction in its corrosion resistance. To avoid this, facing is done with high-alloy electrodes in three and more layers.