Failure Analysis of a High Voltage Feedthrough of Indus-2 Synchrotron Radiation Source

In this paper, a failure analysis of a high voltage feedthrough of the Indus 2 synchrotron radiation source which brought about venting of the vacuum chamber is discussed. A detailed failure analysis demonstrated that the main cause responsible for the failure of the feedthrough was high humidity in the atmosphere surrounding the feedthrough assembly, which resulted in the corrosion of CuSil braze filler alloy at the ground terminal and also caused flashover between positive (+) and ground terminals. Thermal cycling of the insulator due to flashover resulted in spalling of glazed surface layer and assisted crack propagation from the flashover-generated surface defects. The remedial measures recommended to avoid similar failure include: thorough cleaning of feedthrough and its connectors before installation, use gasket-type sealing in the protective cover of the connector on the air side, use of metallic tubes in place of polyurethane cooling water tubes and design change of feedthrough to shift brazed joint to vacuum side.

Высокоточная характеризация сверхмногопериодных AlGaAs/GaAs-сверхрешеток с помощью рентгеновской рефлектометрии на синхротронном источнике

The morphology of Al0.3Ga0.7As / GaAs superlattices grown by molecular beam epitaxy was determined by X-ray reflectometry (including a synchrotron radiation source) and photoluminescence. The thicknesses of the superlattice layers with 100 periods, found using laboratory and synchrotron studies, correlate with an accuracy of ~ 1%. At the synchrotron, beginning with high (> 4−5) Bragg orders, reflection peaks were found that are not observed in measurements with a diffractometer and are apparently associated with the technological features of the growth of such structures. It follows from the analysis that the peaks correspond to modulation in the superlattice with a period 3–5 times greater and characterize the scatter of the thicknesses over the structure depth by several percent.

C–F and C–H bond cleavage mechanisms of trifluoromethane ions in low-lying electronic states: threshold photoelectron–photoion coincidence imaging and theoretical investigations

Dissociative ionization of trifluoromethane (CHF3) is investigated in the 13.9–18.0 eV energy range using the threshold photoelectron–photoion coincidence (TPEPICO) technique coupled to a vacuum ultraviolet synchrotron radiation source.