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The spin relaxation rate of anomalous muonium in a longitudinal magnetic field was measured in a silicon single crystal. The results are treated as the diffusion of anomalous muonium in a silicon crystal.

The International Linear Collider and other proposed high energy e+ e- machines aim to measure with unprecedented precision Standard Model quantities and new, not yet discovered phenomena. One of the main requirements for achieving this goal is a measurement of the incident beam energy with an uncertainty close to 1e-4. This article presents the analysis of data from a prototype energy spectrometer commissioned in 2006--2007 in SLAC's End Station A beamline. The prototype was a 4-magnet chicane equipped with beam position monitors measuring small changes of the beam orbit through the chicane at different beam energies. A single bunch energy resolution close to 5e-4 was measured, which is satisfactory for most scenarios. We also report on the operational experience with the chicane-based spectrometer and suggest ways of improving its performance., To be submitted to Journal of Instrumentation

The lifetime of negative muons in the 129Xe 1s state was measured. The muon capture rate in 129Xe is compared with that in the 132, 136Xe isotopes. The capture rate was found to depend on the mass number of the cited isotopes. The experimental results are compared with the results of calculations by the semiempirical Goulard-Primakoff formula.

μSR—muon spin rotation—and neutron diffraction measurements have been performed with the superconducting La2CuO4+y having an excess oxygen concentration inside the miscibility gap. The crystals belong to the series of high quality single crystals of La2CuO4, which after being doped with extra oxygen, do not reveal any macroscopic structural phase separation for y≤0.03, verified by X-ray and neutron diffraction. The crystal with y = 0.03 undergoes a transition to a short-range ordered magnetic state of spin-glass type. The crystal with y ⋍ 0.02 becomes antiferromagnetic (AFM) below 15K, according to μSR data. However, neutron diffraction do not reveal long range AFM order, implying that coherent regions of AFM phase are too small to be detected as a Bragg reflection. In addition to magnetic ordering the crystals reveal superconductivity with Tc close to TN,f. Presence of magnetic and superconducting transitions in structurally homogeneous system allows the speculation in terms of microscopic or electronic phase separation providing small hole-rich and hole-poor regions, possessing SC and magnetic order respectively.

μSR investigation of magnetic properties of Y 2 Cu 2 O 5 has been performed in the temperature range 4.2–30 K. Besides the known magnetic phase transition at T N1 = 13 K the peculiarity in the temperature dependence of the local magnetic field on muon was observed near T N2 = 7.5 K. The applying of a small external magnetic field of 50 Oe leads to smearing of this peculiarity.

We have performed the muon spin rotation (SR) measurements of the magnetic penetration depth λ in the superconducting ceramical samples BaPb1−xBixO3 with the bismuth content x=0.22, 0.24, 0.26. The magnetic penetration depth has the low temperature value λ(4.3K) = 7900A for x=0.24. The temperature dependence λ(T)−2 have linear behaviour without any saturation down to the temperature 4.3 K.

Muon spin relaxation and neutron diffraction measurements were performed in Y and Pb substituted Bi-2212 superconductors in order to study the correlation between T c and hole density. We observe first an increase of both T c and the superconducting carrier density via hole transfer, but subsequently (at higher “doping”) more and more holes are prevented from forming superconducting pairs.

The superconducting carrier density n , was measured by means of μ + SR spectroscopy in the mixed phase of a series of polycrystalline Bi-based 2212 superconductors with different substitution of Bi 3+ by Pb 2+ . In exactly the same samples the effective valence per Cu-atom V ( Cu ) was determined by neutron powder diffraction. We observed that n , and V ( Cu ) are not proportional to each other in the heavily doped region. This behavior is interpreted as evidence that the carriers become more and more localized with increasing lead content.

The muon depolarization rate σ was measured by Transverse Field μSR and field cooling procedure in an applied magnetic field of 200 mT. By assumption that the muon depolarization rate σ in the 80 K- phase in normal state is small, data from the temperature interval 85–100 K were used to estimate the magnetic field penetration depth in the 110 K- phase of the lead-free ceramic Bi-Sr-Ca-Cu-O superconductor.

The ceramical system La2-xSrx CuO4 was investigated in the temperature range 4.4–270 K. At the concentrations of Sr x=0.0 and 0.01 the formation of the antiferromagnetic state was observed. The results of the investigations of the magnetic ordering in the fluctuating formation region are given. Investigation of the sample with x=0.07 at the temperature T < 13K confirmed the existence of the spin glass state. The values of the magnetic penetration depth at different temperatures for the superconducting samples are given. The influence of the pinning on the magnetic field distribution in the mixed state of the superconductor is discussed.