| Description |
viii, 51 leaves : illustrations ; 29 cm |
| Summary |
"This thesis describes the design, construction, and application of an analog control system for the temperature control of an expansion cloud chamber. During the expansion, the sample gas and the chamber walls are cooled at the same rate so as to maintain adiabaticity. The control system measures the wall temperature with transistor temperature sensors, calculates the gas temperature from the gas pressure using the adiabatic gas law, and generates a control signal proportional to their difference. The control precision is sufficient to allow the chamber to be used in the study of atmospheric phenomena. The chamber is a ten-sided right prism, 61 centimeters high and 48 centimeters in diameter. It has a sensitive volume of 0.11 meters cubed and an inner wall surface of 1.3 meters squared which is cooled by 844 thermoelectric units imbedded between the inner wall and heat sink. The heat sink is thermostated by liquid coolant that carries away the heat transferred out of the chamber by the thermoelectric units. The maximum power transfer is 40 kilowatts and the maximum rate of cooling is 1.3 °C per second. The preliminary experiments, however, will be run at a rate of 0.005°C per second. The large amount of thermoelectrics are needed to decrease the temperature gradient on the chamber's inner walls. The large amount of power will be needed for later, more dynamic atmospheric phenomena. Since the primary objective of the Cloud Simulation Chamber is to have adiabatic expansions, the gas temperature and the wall temperature must be the same. Special efforts were made to control these temperatures within the allowable difference of a few millidegrees Kelvin for the expected expansion. It is hoped that this thesis will serve as a reference which will insure the future continuity of the Cloud Simulation Chamber"--Abstract, leaves ii-iii. |
|
