Vibrational Circular Dichroism Measurement in the Frequency Range of 800 to 650 cm−1

The development of dispersive instrumentation for the measurement of vibrational circular dichroism (VCD) with a lower frequency limit of ∼650 cm−1 is reported. VCD spectra of 3-methylcyclohexanone, α-pinene, and 3-bromocamphor in the frequency range of 800 to 650 cm−1 are presented to illustrate instrumental performance. The spectra obtained are superior to earlier spectra obtained with the use of a Fourier transform spectrometer.

A Scanning Algorithm for Condensed-Phase CARS and Folded Boxcars

A scanning algorithm for condensed-phase CARS and folded BOXCARS along with the necessary optical alignment hardware for folded BOXCARS have been developed. Due to the unique geometry of the folded BOXCARS beams, the CARS signal is sufficiently isolated from the pump and Stokes beams such that extended spectra with a lower frequency limit of 70 cm−1 have been obtained.

Solar noise observations from the Alouette satellite

Solar radio noise in the frequency range 1.5 to 10 MHz appears sporadically in the Alouette sweep-frequency recordings above the galactic noise level. The type III bursts can be readily identified, but other spectral types are much more difficult to identify from only the satellite records. Using a plausible model for the coronal electron densities, the Type III frequency drift curves have been interpreted as corresponding to a source velocity in the range 0.1 to 0.15 times the velocity of light. Preliminary estimates have also been made of the coronal temperatures from some of the burst durations.Other solar noise events of longer duration have not been classified other than as enhanced solar noise at this stage. These enhancements frequently show an intensity structure, extending down to the 1.5 MHz lower frequency limit of the equipment. These events are discussed briefly.