The GEMPix detector Murtas, F.
Radiation measurements,
11/2020, Volume:
138
Journal Article
Peer reviewed
Open access
The GEMPix is a novel detector developed at CERN, designed and built by coupling a small triple Gas Electron Multiplier with a quad Timepix ASIC for the readout. This structure has the advantage to ...have higher sensitivity to soft X-ray and high radiation tolerance for good spatial resolution of 2D images of intense particle beams. Several applications of this detector have been studied in the last years and some of them will be described in detail.
•The GEMPix is a novel Micro Pattern Gas Detector with a sub-millimetric pads readout performed using 4 Timepix ASIC chip.•This detector is radiation tolerant, sensitive to soft X-rays (below 5 keV) and able to measure high flux of particles.•The detector has been used in Burning Plasma diagnostics and in 3D reconstruction of the Bragg peak of Hadron-therapy beam.•It can be used also for the studies and optimization of gas detectors.•Future use in micro dosimetry measurements using tissue equivalent gas mixture.
The W-MON project goal is to establish an automatic control mechanism of the presence of radioactive material in conventional waste containers at CERN using a distributed network of interconnected ...low-power radiation sensors. This network facilitates continuous data recording, transfer and storage in a database while allowing online and offline data analysis, in addition to alarm triggering. Data transmission, processing and evaluation is achieved by a centralized IoT end-to-end data architecture that has been developed for real-time monitoring and visualization of the radiation levels in waste containers. In this paper the results of field tests of the W-MON system described in two previous papers are presented for three different types of sensors. Estimation of failure detection probability, long-term stability tests and sensitivity studies carried out using radioactive samples of various activities placed in standard waste containers are described. A comparison between the manual monitoring procedure currently used at CERN and the W-MON system is discussed in detail.
•W-MON system is a network of low-power radiation sensors.•Automatic control of radioactive material in waste containers at CERN.•Centralized IoT architecture enables continuous data transmission.•Real-time monitoring and visualization of radiation levels.•Long-term stability tests using radioactive samples in standard containers.•W-MON system can efficiently replace existing manual monitoring procedures.
A pixelated 2-D detector combining chemical-vapor-deposited diamond and the Timepix3 chip ("Diamondpix") is presented. Its conceptual design with a brief description of the Timepix3 chip acquisition ...modes is outlined. The performance has been tested with fluorescence X-rays, fast neutrons, and electron beam. A first energy calibration has been obtained with X-rays and compared with an equivalent silicon Timepix3 detector. Measurements on fast neutrons and other radioactive source demonstrated a good gamma/neutron rejection capability. Moreover, Diamondpix has been exposed to a beam of ultrarelativistic electrons showing that it can act as a very powerful monitor of beam position, measuring simultaneously the charge released inside the detector and the time of arrival (ToA) of the particles by reconstructing the time profile of the beam bunches. Finally, high-intensity measurements show some delayed signals probably related to the trap defects inside the diamond. The first study of their spatial distribution correlated with the measurements of the charge released inside the diamond and ToA is also discussed.
The W-MON project aims to improve and automatize the control of the presence of radioactive material in conventional waste containers at CERN using a distributed network of interconnected low-power ...radiation sensors. The key development is the integration of a lightweight but sensitive radiation sensor in a powerful network that allows continuous data recording, transfer and storage in a database for alarm triggering and subsequent data analysis. The Chiyoda D-shuttle personal dosimeter was used as proof-of-concept. Extensive tests performed with the commercial version of the D-shuttle showed that its robustness, stability under variable thermal conditions, high sensitivity and hourly dose logging capabilities make it a strong candidate for the project. To comply with the requirements of remote operation and wireless data transmission to a central server, a customized version of the D-shuttle has been developed. Two additional radiation sensors are also currently being considered. The sensors have been coupled to a custom-made communication board allowing for long-range low-power LoRa wireless data transmission. A centralized IoT (Internet of Things) end-to-end data architecture has been developed for real-time monitoring and visualization of the radiation level in waste containers before the final integration into REMUS, the overall CERN Radiation and Environment Monitoring Unified Supervision service.
•Environmental radiological monitoring for conventional waste.•Lightweight and smart radiation sensors for real-time monitoring of the radiation level in waste containers.•Distributed network of interconnected low-power radiation sensors with LoRa wireless data transmission.
Silicon Carbide (SiC) is a relatively new entry in the world of solid-state detectors. Although SiC response to neutrons is more complex than the one obtained with diamonds, the measured energy ...resolution (FWHM/Ed<4%) makes SiC an interesting alternative to diamond and silicon detectors for fast neutrons. The results obtained from the measurements of the response of a 100μm thick SiC detector to neutrons in the energy range between 3 and 20 MeV at the n_TOF spallation source at CERN are presented in this paper.
By selecting the neutron energy by means of the time of flight, the detector response to quasi-mono-energetic neutrons was measured. The main neutron-induced nuclear reactions were identified in the measured pulse height spectrum. Detection efficiency as a function of neutron energy was measured and interpreted based on available neutron cross section and by making use of Monte Carlo simulations.
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