摘要：We present a method to determine the bulk temperature of a single crystal diamond sample at an
X-Ray free electron laser using inelastic X-ray scattering. The experiment was performed at the high
energy density instrument at the European XFEL GmbH, Germany. The technique, based on inelastic
X-ray scattering and the principle of detailed balance, was demonstrated to give accurate temperature
measurements, within 8% for both room temperature diamond and heated diamond to 500 K.
Here, the temperature was increased in a controlled way using a resistive heater to test theoretical
predictions of the scaling of the signal with temperature. The method was tested by validating the
energy of the phonon modes with previous measurements made at room temperature using inelastic
X-ray scattering and neutron scattering techniques. This technique could be used to determine the
bulk temperature in transient systems with a temporal resolution of 50 fs and for which accurate
measurements of thermodynamic properties are vital to build accurate equation of state and transport
models.
