Accession Number : AD0692118

Title :   INVESTIGATION OF DEFECTS IN ICE USING POSITRON ANNIHILATION (PROJECT PAN).

Descriptive Note : Final rept.,

Corporate Author : CORNELL AERONAUTICAL LAB INC BUFFALO N Y

Personal Author(s) : Livingston,William A. ; Malone,Dennis P.

Report Date : 30 SEP 1968

Pagination or Media Count : 59

Abstract : Water substance, at temperatures below and just above its melting point, is not a pure liquid or solid as classical approaches would suggest. Rather, it is evident that at temperatures just above the melting point the liquid phase contains molecular groupings which, because of temporary bonding, have more ice-like than liquid-like characteristics. Similarly, at temperatures colder than zero degrees Celsius liquid-like clusters of molecules exist on a statistical basis. Indeed, a three-component behavior is adduced, the relative importances of the three as controlling phenomena being different as temperature is altered. Because electronic bonds in hydrogen are involved in these interior changes of state, the phenomenon is amenable to study by the method of positron annihilation. In such an investigation, the existence of temporarily broken electron bonds (defects) is statistically assessable because the (defect) electrons are more likely than bound ones to combine with positrons in the annihilation process. This report provides a theoretical background and outlines and experimental attack on the problem of this defect structure in liquid water and ice. (Author)

Descriptors :   (*ICE, *CRYSTAL DEFECTS), (*POSITRONS, ICE), (*WATER, DEFECTS(MATERIALS)), ANNIHILATION REACTIONS, ELECTRONS, CHEMICAL BONDS, MOLECULAR ASSOCIATION

Subject Categories : Snow, Ice and Permafrost
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE