Accession Number : AD0745348

Title :   Nonadiabatic Effects in Cloud Chamber Expansions,

Corporate Author : BROWN UNIV PROVIDENCE R I DIV OF ENGINEERING

Personal Author(s) : Eklund,Thor I.

Report Date : JUN 1972

Pagination or Media Count : 31

Abstract : An energy balance was applied to the expansion process that occurs in a Wilson cloud chamber, and the nonadiabatic effects were thereby quantified. Chamber pressure, volume, and optical transmission were recorded continuously on a high-speed oscillograph, and this yielded highly accurate data both for chamber pressure against volume and for onset of condensation as a function of time. Both moist and dry argon were tested, and comparisons with theoretical values of heat transfer were made. Effective polytropic coefficients were defined, and the polytropic coefficients for the wet argon tests were used to calculate critical supersaturation. These actual critical supersaturations were compared with those computed for equivalent adiabatic expansions. The critical supersaturations were compared with the data of Wilson and Powell and also with the predictions from classical nucleation theory. (Author)

Descriptors :   (*CLOUD CHAMBERS, CONDENSATION), HEAT TRANSFER, NUCLEATION, THERMAL EXPANSION, PRESSURE, ARGON

Subject Categories : Nuclear Instrumentation

Distribution Statement : APPROVED FOR PUBLIC RELEASE