Topic: 31d Title: 3D Diamond Detector for High-Rate Charged Particle Tracking

Detectors for very rare phenomena in high-intensity experiments require extreme precision of charged particle tracking at low momenta in sub-100 MeV/c range. This necessitates ultra-low mass design that corresponds to very thin detector thickness. In addition, the particle collision rates in future high-intensity experiments will increase by approximately one order of magnitude, imposing severe radiation tolerance and/or cooling technology requirements on the performance of the charged particle tracking detectors which may already be beyond current technology. Therefore the next generation detector systems must provide resolutions ranging down to tens of microns or lower in space, sub-hundred of psec in time, handle average rates up to 10 MHz/cm2 or higher, and may have to operate in radiation environments much harsher than the current level. We will develop a new ultra-low mass diamond detector technology based on 3D geometrical structures that can overcome current limitations by combining the inherent advantages of diamond material (high thermoconductivity, high radiation tolerance, very short charge collection time, very low leakage currents) with advanced 3D femtosecond laser writing capabilities of micrometer-scale conductive graphitic structures fabrication inside bulk diamond substrates. This technology will allow the creation of arbitrary 3D geometries for electrodes and wiring embedded inside the insulating diamond. It can be optimized for a specific application. For example, embedded wiring will allow relocating high voltage and readout connections from the conventional top and bottom detector sides to the edge sides. It makes technology stackable. It also provides for significant reduction the number of readout channels for prescribed spatial resolution (with a consequential reduction of the amount of interface electronics and power consumption). The extremely high diamond thermoconductivity will allow the devices to operate at room temperature, extracting heat without any additional expensive cooling support. In addition, detectors constructed in the proposed manner will have radiation tolerance and longevity. All these features make the novel technology very compact and cost- effective. We plan to build a diamond 3D detector with high position resolution (10-20 microns), sub-100 ps time resolution, and rate tolerance up to 20 MHz/cm2. Under Phase 1 of the project, we will focus on the optimal 3D geometry structure calculations and design. We will also test several techniques for the optimum fabrication procedure of laser written nano-carbon wires with improved structural and electrical properties. In particular, power density control, aberration correction and graphitization rate will be optimized and characterized. The disruptive approach we propose will overcome conventional limitations of current state-of-the-art technology on radiation tolerant, cost-effective, high-resolution particle tracking detectors. The truly three-dimensional diamond detector technology may find its application in HL-LHC experiment with increased radiation environment level and rigid requirements for time and space resolution. The invention has high commercialization potential on other future HEP experiments around the world and beyond HEP research by way of medical, industrial, security, and scientific applications.