The increase of luminosity at High Luminosity LHC will require the introduction of tracker information at Level-1 trigger system for the experiments to maintain an acceptable trigger rate to select ...interesting events despite the one order of magnitude increase in the minimum bias interactions. To extract in the required latency the track information a dedicated hardware has to be used. We present the tests of a prototype system (Pattern Recognition Mezzanine) as core of pattern recognition and track fitting for HL-LHC ATLAS and CMS experiments, combining the power of both Associative Memory custom ASIC and modern Field Programmable Gate Array (FPGA) devices.
In this work we propose a combined TCAD and Geant4 simulated based numerical model approach to study of the active electrical behavior of 3D diamond sensors with graphitic parallel columns/trenches ...contact scheme in those radiation detection applications ruled by stringent timing and radiation-tolerance requirements. Single particle hit effects can be realistically assessed in Geant4 simulations describing properly the energy deposition along its path. Such information represents the input to the TCAD tools for analyzing the detectors active response depending on bias, particle type, energy and impact direction. Different contact geometries and transport effects have been accounted for with the equivalent load effect of graphitic columns in mixed-mode simulations for the device performance optimization.
A new prototype 3D diamond dosimeter featuring laser-written graphitic surface connections and bonding pads has been tested. Diamond substrates are of interest to medical dosimetry as they are closer ...to bodily tissue equivalence than other solid-state materials. The device in this work was made with a polycrystalline chemical vapour deposition diamond substrate (pCVD) was laser processed to have internal 3D electrode columns and surface connections including the wire-bonding pads to make an all‑carbon detector, with no metal-diamond interfaces. Polycrystalline diamond can be produced with a larger area and cheaper cost than single crystal diamond, but has a relatively slow timing response due to charge trapping defects inside the substrate. To mitigate material defects, 3D sensor technology has been proposed. The 3D design has charge collection electrodes as columns spaced inside the material bulk perpendicular to the surface. When compared to the conventional ‘planar’ sensor design, the 3D arrangement decouples the charge collection distance from the thickness of the substrate, theoretically allowing for more efficient charge collection and the active volumes have smaller dimensions. The laser writing process used for the 3D columns was extended to make graphitic surface connections replacing conventionally used metal bonding contacts between the 3D graphitic columns and readout electronics. The removal of metal-diamond contacts in the detector volume reduces the distortion of the electric field close to the surface of the diamond. The prototype was tested using a laboratory X-ray tube and a clinical Elekta Synergy BM LINAC and was found to have dose-rate independence consistent with previous 3D diamond dosimeters but with lower operating voltages, the lowest being +6 V. Lower operating voltage is attributed to the removal of the electric field distortion at diamond-metal interfaces. This paper proposes the first implementation of an all‑carbon 3D diamond dosimeter using a polycrystalline substrate.
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•A 3D diamond detector has laser-inscribed electrode columns inside of the diamond.•3D design offers radiation tolerance in addition to diamond tissue equivalence.•Graphitic surface traces instead of metal are used to connect the electrodes.•Prototype device shows a current response linear with dose-rate.
The characterization of high intensity charged particle beams at medical accelerators poses several challenges. In this work, we investigate the use of a highly segmented CMOS Image Sensors (CIS), an ...MT9T031 from Aptina, as a way to study the spatial homogeneity and the time stability of the beam. The approach relies on the possibility to define many adjacent small regions that perform the radiation flux measurement with sufficient precision (below 1%) to extract the spatial structure of the beam. The device has been exposed to a 10 MeV therapeutic electron beam at Santa Maria Hospital (Terni, Italy) to measure the electron flux at a distance of 140 cm. The whole sensor, using a non-linear calibration, has measured the value of the flux, then the segmentation approach has been applied to study the spatial structure of the beam. Concerning the variation in time, the current limitation of a rolling shutter CIS limits the capability to disentangle the time structure of the beam. However, in light of the possibility to obtain some CIS with the new global shutter architecture, having integration time of the order of a few tens of microseconds, the measurement procedure has been implemented and tested using ∼1Hz frequency frame-rate, to study its limits. Uncertainty of the order of 0.5% has been reached for measurement of both spatial and time beam homogeneity.
•CIS devices could be used as spatially very precise ionizing radiation detectors.•Non-linear calibration could be used to keep uncertainty at the 1% level.•The intrinsic homogeneous response of CIS to ionizing radiation over the whole surface open the way for uncertainty disentangling procedures.
The Compact Muon Solenoid (CMS) is one of the experiments at the Large Hadron Collider (LHC) under construction at CERN. Its inner tracking system consist of the world largest Silicon Strip Tracker ...(SST). In total it implements 24,244 silicon sensors covering an area of
206
m
2
. To construct a large system of this size and ensure its functionality for the full lifetime of 10 years under LHC condition, the CMS collaboration developed an elaborate design and a detailed quality assurance program. This paper describes the strategy and shows first results on sensor qualification.
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