A new spectrometer

Part of the HotCore project will involve experiments under high pressure and high temperature, with a target of over 100 GPa (1 megabar) and several thousands of kelvin.

Measuring sample temperatures inside a diamond anvil cell in this temperature range is no trivial task. One needs a decent spectrometer and camera. The idea is simple and was already described by Bassett (and others) in 1986: one can use the quasi-black-body spectrum of the incandescent light given off by the sample! The radiation is emitted according to Planck's law, meaning that it has a spectrum that is determined by the temperature alone, not by the body's shape or composition, as described by this page on wikipedia.

To do so, we needed an upgrade to our 15 years old spectrometer and camera system. It is now done! Our new versatile spectrometer comes with three gratings, one optimized for temperature measurements by fitting Planck's law, and two additional grating dedicated to ruby fluorescence and additional Raman measurements.

Let's add a couple of optomechanics parts, lenses, and mirrors, and we should be ready to go!