The Role of lasers in electron-atom collision physics

1996 ◽  
Author(s):  
Max Standage
Keyword(s):  
Electron Atom ◽  
Atom Collision

scholarly journals The constitution of the aluminium-rich aluminium-cobaltcopper alloys, with special reference to the role of transitional metals in alloy formation

1949 ◽  
Vol 197 (1050) ◽  
pp. 321-335 ◽  
Keyword(s):  
Solid Solution ◽  
Ternary Compound ◽  
Copper Alloys ◽  
Primary Crystallization ◽  
Alloy Formation ◽  
Atom Ratio ◽  
Transitional Metals ◽  
Ternary Compounds ◽  
Electron Atom

An experimental investigation of aluminium-rich aluminium-cobalt-copper alloys has shown that, as in the alloys of alumiinium and copper with nickel and iron respectively, a ternary compound, in addition to the phases Co 2 Al 9 and CuAl 2 , enters into equilibrium with the primary solid solution. Isothermal sections of the ternary model have been established at 530° and 500° C; the field in which the solid solution, α , and the ternary compound, T (CoCu), are in equilibrium is very narrow, while the ( α + Co 2 Al 9 ), ( α + Co 2 Al 9 + T (CoCu)) and ( α + T (CoCu)+CuAl 2 ) phase fields are relatively extensive. The presence of T (CoCu), and its formation peritectically from Co 2 Al 9 , have been confirmed by further experiments on solid and semi-liquid alloys and, from the examination of slowly cooled alloys, the appropriate fields of primary crystallization have been determined. The composition range in which T (CoCu) separates as primary crystals is restricted, and, for this and other reasons, pure samples of T (CoCu) cannot be obtained for analysis. Extrapolation of the accurately established ( α + T (CoCu) + CuAl 2 )/( α + T (CoCu)) and ( α + T (CoCu) + CuAl 2 )/( T (CoCu) + CuAl 2 ) boundaries, however, showrs that the homogeneity range of T (CoCu) includes the composition Co 2 Cu 5 Al 16 . The solubility of copper in Co 2 Al 9 does not exceed 1·44% at 570° C. In discussion, it is showm that the ternary compounds NiCu 3 Al 6 and FeCu 2 Al 7 occur at the same electron: atom ratio, according to the authors’ theory of the role of transitional elements in alloy formation. The compound T (CoCu) forms a third member of the same series and is probably of the ideal composition Co 2 Cu 5 Al 13 . The results support the hypothesis of absorption of electrons by transitional metal atoms present in aluminium-rich alloys, and also that the occurrence of ternary compounds is influenced to a marked degree by the electron: atom ratio.

A high density metastable helium MOT for electron-atom collision studies

2004 ◽  
Author(s):  
Kenneth G. Baldwin ◽  
Linda J. Uhlmann ◽  
Robert G. Dall ◽  
Andrew G. Truscott ◽  
Stephen J. Buckman
Keyword(s):  
High Density ◽  
Metastable Helium ◽  
Electron Atom ◽  
Atom Collision
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