Development of 3D diamond detectors for application in future particle physics experiments

Chemical Vapour Deposition (CVD) diamond is a wide band-gap material which features high radiation hardness and low leakage current, making it suitable for building solid state detectors for high energy physics and radiotherapy dosimetry applications. 3D diamond detector is a relatively new concept that is characterised by an electrode array fabricated inside a CVD diamond plate using a femto-second laser, resulting in electrically conducting graphitic paths. This fabrication method allows for various complicated electrode structures, making it possible to design novel electrode geometries and optimise the temporal/spatial performance of 3D diamond devices. In this paper, multiple 3D diamond detector structures are modelled. Their electric fields are simulated using Sentaurus TCAD, and the signal response is simulated with Monte Carlo method using Garfield++. Utilising these simulation tools, the performance of different 3D diamond detector structures are analysed. To test the detector performance experimentally, detector prototypes with various structures are built with a femto-second laser equipped with an optical correction using Spatial Light Modulators (SLMs). The Two Photon Absorption (TPA) technique is used to generate point-like charge distributions inside 3D diamond sensor, so that the detector response can be examined with high spatial and temporal resolution.