ABSTRACT
The effect of positive and negative pressure on the modes of oscillation of a multielectron bubble in liquid helium is calculated. Already at low pressures of the order of 10-100 mbar, these effects are found to significantly modify the frequencies of oscillation of the bubble. Stabilization of the bubble is shown to occur in the presence of a small negative pressure, which expands the bubble radius. Above a threshold negative pressure, the bubble is unstable.
ABSTRACT
A moderate resolution vacuum far in spectrometer has been built with a data acquisition system designed for computer processing of the data. The spectral range of the instrument is 20-1600 micro. Sensitive low temperature bolometer detectors have been made of doubly doped silicon. The radiation filtering scheme is discussed in detail. In addition, an analysis is made of the effect of detector noise and impurity radiation on the accuracy of the results. Sample spectra illustrating the performance of the instrument are presented.
