Shedding light on temperature
A new non-contact luminescence lifetime technique reveals accurate temperature information
Diamond scientists have developed, in collaboration with University of Oxford, a non-contact luminescence lifetime cryothermometry technique to measure the sample temperature on the Long Wavelength Macromolecular Crystallography (MX) beamline (I23) at Diamond Light Source. Monitoring the sample temperature is critical for in vacuum protein crystallography to ensure cryogenic temperatures are maintained during experiments.
A recent publication in the Journal of Synchrotron Radiation reports how this technique is integrated into the I23 beamline and can measure sample temperature under vacuum in the operation range of 30 to 150 Kelvin (-243 to -123°C) with an accuracy of 0.6 Kelvin (0.6°C). It has also been used to characterise the thermal performance of MX sample mounts. This technique demonstrates its usefulness in MX experiments and in the improvement of investigation design.
In developing this technique for use on I23, the beamline team worked with Professor Hans Kraus at the University of Oxford. Previous work by Dr Mykhaylyk into the thermal properties of scintillators also led to the selection of the scintillator BGO (Bi4Ge3O12) found to be sensitive in the I23 beamline operation range (30 to 150 Kelvin; -243 to -123°C) and is excitable using ultraviolet (UV) radiation from LEDs. This is the first application of scintillation materials in luminescence lifetime cryothermometry.
Facile system integration
A significant driver in the success of the non-contact technique on I23 was the ease at which it could be integrated onto the beamline. Dr Mykhaylyk reported “practically integration of this idea into the environment of the beamline went very smoothly and didn’t require significant effort of development”. The current sample viewing system has been simply modified with an addition of a motorised mirror allowing luminescence light to be directed towards a photodetector whilst a previously known method for luminescence data collection and analysis is used to determine decay characteristics.
All-encompassing sample temperature information
To find out more about using the non-contact cryothermometry technique on I23, or to discuss potential applications, please contact Principal Beamline Scientist Dr Armin Wagner: firstname.lastname@example.org.