Joshua E. Vaughan - Honors in Physics
Trace Detection of Gaseous Carbon Disulfide With an Optoacoustic Technique
Gaseous CS2 was studied using a pulsed nitrogen laser and an optoacoustic technique. A test cell was constructed to contain the CS2 and resonate at 1000 Hz. CS2 strongly absorbs energy at the wavelength of the nitrogen laser, 337 nanometers, and, therefore, heats rapidly when exposed to the laser. Because the laser was pulsed at a periodic frequency, the CS2 gas heated and cooled periodically. The periodic heating and cooling of the gas within the constant volume test cell resulted in periodic increases and decreases in pressure, or a sound wave. This sound wave was detected using a microphone placed inside the test cell.