Study on residual gas composition in 316L stainless steel-quartz glass hybrid ultra-high vacuum sealed tube

2021 ◽  
Author(s):  
Yulong Tang ◽  
Yuling He ◽  
Yansong Meng ◽  
Weiwei Wang ◽  
Rongyan Zhang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Quartz Glass ◽  
316L Stainless Steel ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Gas Composition ◽  
Residual Gas

scholarly journals Laser power meters as an X-ray power diagnostic for LCLS-II

2018 ◽  
Vol 25 (1) ◽  
pp. 72-76 ◽  
Author(s):  
Philip Heimann ◽  
Stefan Moeller ◽  
Sergio Carbajo ◽  
Sanghoon Song ◽  
Georgi Dakovski ◽  
...  
Keyword(s):  
Free Electron Laser ◽  
Laser Power ◽  
High Vacuum ◽  
Average Power ◽  
Gas Analysis ◽  
Ultra High Vacuum ◽  
Beam Path ◽  
X Ray ◽  
High Repetition ◽  
Residual Gas

For the LCLS-II X-ray instruments, laser power meters are being developed as compact X-ray power diagnostics to operate at soft and tender X-ray photon energies. These diagnostics can be installed at various locations along an X-ray free-electron laser (FEL) beamline in order to monitor the transmission of X-ray optics along the beam path. In addition, the power meters will be used to determine the absolute X-ray power at the endstations. Here, thermopile power meters, which measure average power, and have been chosen primarily for their compatibility with the high repetition rates at LCLS-II, are evaluated. A number of characteristics in the soft X-ray range are presented including linearity, calibrations conducted with a photodiode and a gas monitor detector as well as ultra-high-vacuum compatibility tests using residual gas analysis. The application of these power meters for LCLS-II and other X-ray FEL sources is discussed.

Interfacial Dislocations in (111) Ag-Cu Bilayers

1973 ◽  
Vol 31 ◽  
pp. 112-113
Author(s):  
C. T. Homg ◽  
R. W. Vook
Keyword(s):  
High Vacuum ◽  
Ultra High Vacuum ◽  
Two Dimensional ◽  
Double Diffraction ◽  
Cu Films ◽  
Interfacial Dislocations ◽  
Residual Gas ◽  
Diffraction Effects ◽  
Work Up

Smooth (111) single crystal Cu films (1200Å) were evaporated on NaCl/mica in an ultra-high vacuum RHEED systemI (base pressure ≤1×10−9 torr) The total residual gas pressure during Cu evaporation was less than 1×10−8 torr. These Cu films served as substrates for thin epitaxial monolayer Ag growth ranging in thickness from 1Å to 20Å, as measured by a quartz thickness monitor. These Ag-Cu bilayers were formed and examined in-situ in the RHEED system.The unusual RHEED patterns first re orted by Gradmann and Krause were observed in the present work up to l0Å of Ag. Beyond 10Å, only Ag and Cu lines plus double diffraction effects were detected. A typical example of the former is given in Fig. 1. The pattern was previously interpreted as due to a two dimensional grid of interfacial dislocations.

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