Investigation of cross talk in single grain luminescence measurements using an EMCCD camera

• We have performed single grain OSL measurements using an EMCCD detector.
• Individual equivalent dose cannot be accurately recovered from a mixed dose population.
• Grains are influenced by signal emitted by their neighbours during the measurements.
• Simulated data confirm the strong effect of this phenomenon.
• Increasing the distance between grains or applying brightness criteria are inefficient.

Highly sensitive electron multiplying charges coupled devices (EMCCD) enable the spatial detection of luminescence emissions from samples and have a high potential in single grain luminescence dating. However, the main challenge of this approach is the potential effect of cross talk, i.e. the influence of signal emitted by neighbouring grains, which will bias the information recorded from individual grains. Here, we present the first investigations into this phenomenon when performing single grain luminescence measurements of quartz grains spread over the flat surface of a sample carrier. Dose recovery tests using mixed populations show an important effect of cross talk, even when some distance is kept between grains. This issue is further investigated by focusing just on two grains and complemented by simulated experiments. Creation of an additional rejection criteria based on the brightness properties of the grains is inefficient in selecting grains unaffected by their surroundings. Therefore, the use of physical approaches or image processing algorithms to directly counteract cross talk is essential to allow routine single grain luminescence dating using EMCCD cameras.