7 research outputs found
Superconducting Accelerating RF-Structure Stability at a High Energy Level from the Point of View of Thermal Balance
The influence of working gas pressure on interlayer mixing in magnetron-deposited Mo/Si multilayers
Impact of Ar gas pressure (1β4 mTorr) on the growth of amorphous interlayers in Mo/Si multilayers deposited by magnetron sputtering was investigated by small-angle x-ray scattering (l=0.154 nm) and methods of cross-sectional transmission electron microscopy. Some reduction of thickness of the amorphous inter-layers with Ar pressure increase was found, while composition of the layers was enriched with molybdenum. The interface modification resulted in raise of EUV reflectance of the Mo/Si multilayer
Damage to extreme-ultraviolet Sc/Si multilayer mirrors exposed to intense 46.9-nm laser pulses
Includes bibliographical references (page 622).The damage threshold and damage mechanism of extreme-ultraviolet Sc/Si multilayer mirror coatings are investigated with focused nanosecond pulses at 46.9-nm radiation from a compact capillary-discharge laser. Damage threshold fluences of ~0.08 J/cm2 are measured for coatings deposited on both borosilicate glass and Si substrates. The use of scanning and transmission electron microscopy and small-angle x-ray diffraction techniques reveals the thermal nature of the damage mechanism. The results are relevant to the use of newly developed high-flux extreme-ultraviolet sources in applications
Structural transformations in Sc/Si multilayers irradiated by EUVlasers
Multilayer mirrors for the extreme ultraviolet (EUV) are keyelements for numerous applications of coherent EUV sources such as newtabletop lasers and free-electron lasers. However the field ofapplications is limited by the radiation and thermal stability of themultilayers. Taking into account the growing power of EUV sources thestability of the optics becomes crucial. To overcome this problem it isnecessary to study the degradation of multilayers and try to increasetheir temporal and thermal stability. In this paper we report the resultsof detailed study of structural changes in Sc/Simultilayers when exposedto intense EUV laser pulses. Various types of surface damage such asmelting, boiling, shockwave creation and ablation were observed asirradiation fluencies increase. Cross-sectional TEM study revealed thatthe layer structure was completely destroyed in the upper part ofmultilayer, but still survived below. The layers adjacent tothe substrateremained intact even through the multilayer surface melted down, thoughthe structure of the layers beneath the molten zone was noticeablychanged. The layer structure in this thermally affected zone is similarto that of isothermally annealed samples. All stages of scandium silicideformation such as interdiffusion, solid-state amorphization, silicidecrystallization, etc., are present in the thermally affected zone. Itindicates a thermal nature of the damage mechanism. The tungstendiffusion barriers were applied to the scandium/silicon interfaces. Itwas shown that the barriers inhibited interdiffusion and increased thethermal stability of Sc/Si mirrors
Structural transformation in C/Si multilayer after annealing
Amorphous C/Si multilayers were prepared by DC magnetron sputtering technique and investigated by transmission electron microscopy and low-angle x-ray diffraction methods after annealing at 650 and 950 Β°C. The amorphous interlayers of 0.5 β 0.6 nm thick were found at C/Si and Si/C interfaces being of different density and composition. Amorphous structure of the multilayer is stable up to 950 Β°C when crystallization of Ξ±-SiC occurs and voids form in Ξ±-Si layer.ΠΠ·Π³ΠΎΡΠΎΠ²Π»Π΅Π½Π½ΡΠ΅ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΏΡΡΠΌΠΎΡΠΎΡΠ½ΠΎΠ³ΠΎ ΠΌΠ°Π³Π½Π΅ΡΡΠΎΠ½Π½ΠΎΠ³ΠΎ ΡΠ°ΡΠΏΡΠ»Π΅Π½ΠΈΡ Π°ΠΌΠΎΡΡΠ½ΡΠ΅ ΠΌΠ½ΠΎΠ³ΠΎΡΠ»ΠΎΠΉΠ½ΡΠ΅ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠΈΠΈ C/Si Π±ΡΠ»ΠΈ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½Ρ ΠΌΠ΅ΡΠΎΠ΄Π°ΠΌΠΈ ΠΏΡΠΎΡΠ²Π΅ΡΠΈΠ²Π°ΡΡΠ΅ΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠ½Π½ΠΎΠΉ ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠΏΠΈΠΈ ΠΈ ΠΌΠ°Π»ΠΎΡΠ³Π»ΠΎΠ²ΠΎΠΉ ΡΠ΅Π½ΡΠ³Π΅Π½ΠΎΠ²ΡΠΊΠΎΠΉ Π΄ΠΈΡΡΠ°ΠΊΡΠΈΠΈ ΠΏΠΎΡΠ»Π΅ ΠΎΡΠΆΠΈΠ³ΠΎΠ² ΠΏΡΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ΅ 650 ΠΈ 950 Β°C. ΠΠ° Π³ΡΠ°Π½ΠΈΡΠ°Ρ
ΡΠ°Π·Π΄Π΅Π»Π° C/Si ΠΈ Si/C ΠΎΠ±Π½Π°ΡΡΠΆΠ΅Π½Ρ Π°ΠΌΠΎΡΡΠ½ΡΠ΅ ΠΏΠ΅ΡΠ΅ΠΌΠ΅ΡΠ°Π½Π½ΡΠ΅ Π·ΠΎΠ½Ρ ΡΠΎΠ»ΡΠΈΠ½ΠΎΠΉ 0.5 β 0.6 Π½ΠΌ c ΡΠ°Π·Π»ΠΈΡΠ½ΡΠΌΠΈ ΠΏΠ»ΠΎΡΠ½ΠΎΡΡΡΡ ΠΈ ΡΠΎΡΡΠ°Π²ΠΎΠΌ. ΠΠΌΠΎΡΡΠ½Π°Ρ ΡΡΡΡΠΊΡΡΡΠ° ΠΌΠ½ΠΎΠ³ΠΎΡΠ»ΠΎΠΉΠ½ΠΎΠΉ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠΈΠΈ ΡΡΠ°Π±ΠΈΠ»ΡΠ½Π° Π²ΠΏΠ»ΠΎΡΡ Π΄ΠΎ 950 Β°C, ΠΊΠΎΠ³Π΄Π° Π½Π°Π±Π»ΡΠ΄Π°Π΅ΡΡΡ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΠΏΠΎΡ Π² ΡΠ»ΠΎΡΡ
Ξ±-Si ΠΈ ΠΊΡΠΈΡΡΠ°Π»Π»ΠΈΠ·Π°ΡΠΈΡ Ξ±-Si