Evaluation of the plasma hydrogen isotope content by residual gas analysis at JET and AUG

The use of NF3 is significantly increasing every year. However, NF3 is a greenhouse gas with a very high global warming potential. Therefore, the development of a material to replace NF3 is required. F3NO is considered a potential replacement to NF3. In this study, the characteristics and cleaning performance of the F3NO plasma to replace the greenhouse gas NF3 were examined. Etching of SiO2 thin films was performed, the DC offset of the plasma of both gases (i.e., NF3 and F3NO) was analyzed, and a residual gas analysis was performed. Based on the analysis results, the characteristics of the F3NO plasma were studied, and the SiO2 etch rates of the NF3 and F3NO plasmas were compared. The results show that the etch rates of the two gases have a difference of 95% on average, and therefore, the cleaning performance of the F3NO plasma was demonstrated, and the potential benefit of replacing NF3 with F3NO was confirmed.

Download Full-text

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

Journal of Synchrotron Radiation ◽

10.1107/s1600577517014096 ◽

2018 ◽

Vol 25 (1) ◽

pp. 72-76 ◽

Cited By ~ 6

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.

Download Full-text

Electron Beam Induced Decomposition of Palladium Acetate

MRS Proceedings ◽

10.1557/proc-236-165 ◽

1991 ◽

Vol 236 ◽

Author(s):

T.J. Stark ◽

T.M. Mayer ◽

P.E. Russell

Keyword(s):

Electron Beam ◽

Thick Films ◽

Gas Analysis ◽

Palladium Acetate ◽

Metallic State ◽

Xps Analysis ◽

Volatile Products ◽

Residual Gas ◽

Induced Decomposition

AbstractA focused electron beam has been used to selectively decompose sub micron thick films of palladium acetate, Pd(OOCCH3)2, resulting in the formation of <0.1μm wide Pd rich features. Resistivity of the palladium acetate film decreased when exposed to doses above 500μC/cm2. Annealing to 160°C further reduces the resistivity of the exposed areas to as low as 100μΔcm. XPS analysis of the exposed areas indicate that the Pd is reduced to a metallic state and that the ratio of C and 0 to Pd drops to 1.5 and 0.6, respectively, after exposure. Residual gas analysis during exposure indicates that CO2 and CH3 are the primary volatile products of the decomposition.

Download Full-text