Optical Photon Simulation with Mitsuba3

Optical photon propagation is an embarrassingly parallel operation, well suited to acceleration on GPU devices. Rendering of images employs similar techniques -- for this reason, a pipeline to offload optical photon propagation from Geant4 to the industry-standard open-source renderer Mitsuba3 has been devised. With the creation of a dedicated plugin for single point multi-source emission, we find a photon propagation rate of $2\times10^{5}$ photons per second per CPU thread using LLVM and $1.2\times10^{6}$ photons per second per GPU using CUDA. This represents a speed-up of 70 on CPU and 400 on GPU over Geant4 and is competitive with other similar applications. The potential for further applications is discussed.Comment: 7 pages, 8 figure

The Urgonian chert from Provence (France): the intra-formation variability and its exploitation in petro-archeological investigations

International audienceUnderstanding details of stone tool procurement and transfers is for a major research avenue in improving our knowledge about prehistoric societies. The accuracy of the provisioning sources identifications is based on the establishment of large regional repositories. Recent studies show that specific investigations on the evolution of cherts were effective in distinguishing primary sources from the various secondary sources of a raw material. In this paper, we focus on another difficulty that is the distinction between different primary sources of the same geological layers. We consider the specific case of the Bedoulian cherts from southeastern France. This chert was exploited and circulated over large distances during the whole prehistoric record. It is particularly known to have been heat-treated during Late Chassey culture (Neolithic). We show in this paper that paleogeographical variability exists due to variations in the bioclastic and detrital components. With the support of foraminifera data, the granulometry of detrital quartz grain provides the possibility to distinguish between different primary sources. A first test in archeological contexts illustrates the efficiency of the method as well as indicates major changes in provisioning practices between upper Paleolithic and Neolithic groups