A large area 100 channel Picosec Micromegas detector with sub 20 ps time resolution

The PICOSEC Micromegas precise timing detector is based on a Cherenkov radiator coupled to a semi-transparent photocathode and a Micromegas amplification structure. The first proof of concept single-channel small area prototype was able to achieve time resolution below 25 ps. One of the crucial aspects in the development of the precise timing gaseous detectors applicable in high-energy physics experiments is a modular design that enables large area coverage. The first 19-channel multi-pad prototype with an active area of approximately 10 cm$^2$ suffered from degraded timing resolution due to the non-uniformity of the preamplification gap. A new 100 cm$^2$ detector module with 100 channels based on a rigid hybrid ceramic/FR4 Micromegas board for improved drift gap uniformity was developed. Initial measurements with 80 GeV/c muons showed improvements in timing response over measured pads and a time resolution below 25 ps. More recent measurements with a new thinner drift gap detector module and newly developed RF pulse amplifiers show that the resolution can be enhanced to a level of 17~ps. This work will present the development of the detector from structural simulations, design, and beam test commissioning with a focus on the timing performance of a thinner drift gap detector module in combination with new electronics using an automated timing scan method

Towards robust PICOSEC Micromegas precise timing detectors

The PICOSEC Micromegas (MM) detector is a precise timing gaseous detector consisting of a Cherenkov radiator combined with a photocathode and a MM amplifying structure. A 100-channel non-resistive PICOSEC MM prototype with 10x10 cm^2 active area equipped with a Cesium Iodide (CsI) photocathode demonstrated a time resolution below 18 ps. The objective of this work is to improve the PICOSEC MM detector robustness aspects; i.e. integration of resistive MM and carbon-based photocathodes; while maintaining good time resolution. The PICOSEC MM prototypes have been tested in laboratory conditions and successfully characterised with 150 GeV/c muon beams at the CERN SPS H4 beam line. The excellent timing performance below 20 ps for an individual pad obtained with the 10x10 cm^2 area resistive PICOSEC MM of 20 MOhm/sq showed no significant time resolution degradation as a result of adding a resistive layer. A single-pad prototype equipped with a 12 nm thick Boron Carbide (B4C) photocathode presented a time resolution below 35 ps; opening up new possibilities for detectors with robust photocathodes. The results made the concept more suitable for the experiments in need of robust detectors with good time resolution

CERN summer student program rapport: A better understanding of gas gain simulations in GEM detectors

The Gaseous Electron Multiplier (GEM) is used for the detection in the detection of ionizing radiation in high-energy physics experiments due to there high gas gain. This CERN summer project aimed to have a better understanding of the discrepancy between theoretically and experimentally obtained effective gas gains of this detector, which is currently a factor of. Our results do not lead to a conclusive cause of this inconsistency but show a significant shift in gas gain due to alterations in the geometry of a GEM hole. In adition, the surface potential of the polyimide in the presence of a surface current has been calculated, the effect of secondary electron emission has shown to be negligible and the electron transport algorithm of Garfield++ has been expanded

Resistive electrodes and particle detectors: Modelling and measurements of novel detector structures

Advancements in nuclear, particle, and astroparticle physics are intricately intertwined with technological progress in experimental instrumentation, particularly in the case of detectors used for precision measurements of the properties of particles. Furthermore, their use in radiation imaging fosters advancements in biomedical and material sciences. An emerging direction of development involves integrating resistive materials into detector architectures to enhance their performance and durability, thereby ensuring compliance with the stringent requirements for measurement precision and operation in more challenging conditions anticipated in future High Energy Physics (HEP) experiments. Continuous advancements in modeling and simulation tools, such as Garfield(++), have guided the widespread development and understanding of detector structures. Since new sensor technologies are proposed regularly, with resistive detectors becoming an ever-increasing fraction of these, it is prudent to reflect this progress in the capabilities of the modeling tools. Up to now, the effects of components with finite conductivity have not been modeled adequately in the software tools that are used for simulating the signal in particle detectors. As part of this thesis, a new framework was developed that is applicable to the wide range of detectors that are inaccessible through analytical means. Laboratory and test beam measurements are used to adjust and validate the simulation framework. Subsequently, the methodology is employed to test and optimize the response of various innovative particle detector readout structures. Through simulation and measurement, we have explored novel solutions in the field of Multi-gap Resistive Plate Chambers, Micro Pattern Gaseous Detectors, and solid-state sensors, arising from the implementation of materials with finite conductivity. In addition to deepening the understanding of existing structures, these studies are necessary for designing and optimising the next generation of particle detectors and their application to specific needs driven by HEP experiments and other applications

Studying signals in particle detectors with resistive elements such as the 2D resistive strip bulk MicroMegas

As demonstrated by the ATLAS New Small Wheel community with their MicroMegas (MM) design,resistive electrodes are now used in different detector types within the Micro Pattern GaseousDetector family to improve their robustness. The extended form of the Ramo-Shockley theorem forconductive media has been applied to a 1 MΩ/□ 2D resistive strip bulk MM to calculatethe signal spreading over neighbouring channels using an 80 GeV/c muon track. For this geometry,the dynamic weighting potential was obtained numerically using a finite element solver by applyinga junction condition and coordinate scaling technique to accurately represent the boundaryconditions of a 10 × 10 cm$^{2}$ active area. Using test beam measurements, the results ofthis model will be used to benchmark this microscopic modelling methodology for signal inductionin resistive particle detectors.As demonstrated by the ATLAS New Small Wheel community with their MicroMegas (MM) design, resistive electrodes are now used in different detector types within the Micro Pattern Gaseous Detector family to improve their robustness or performance. The extended form of the Ramo-Shockley theorem for conductive media has been applied to a 1 M$\Omega$/$\Box$ 2D resistive strip bulk MM to calculate the signal's spreading over neighbouring channels using an 80 GeV/c muon track. For this geometry, the dynamic weighting potential was obtained numerically using a finite element solver by applying a junction condition and coordinate scaling technique to accurately represent the boundary conditions of a $10\times 10$ cm$^2$ active area. Using test beam measurements, the results of this model will be used to benchmark this microscopic modelling methodology for signal induction in resistive particle detectors

Strategic R&D Programme on Technologies for Future Experiments - Annual Report 2020

This report summarises the activities and achievements of the strategic R&D programme on technologies for future experiments in the year 2020

Strategic R&D Programme on Technologies for Future Experiments - Annual Report 2021

This report summarises the activities and main achievements of the CERN strategic R&D programme on technologies for future experiments during the year 2021

Extension of the R&D Programme on Technologies for Future Experiments

we have conceived an extension of the R&D programme covering the period 2024 to 2028, i.e. again a 5-year period, however with 2024 as overlap year. This step was encouraged by the success of the current programme but also by the Europe-wide efforts to launch new Detector R&D collaborations in the framework of the ECFA Detector R&D Roadmap. We propose to continue our R&D programme with the main activities in essentially the same areas. All activities are fully aligned with the ECFA Roadmap and in most cases will be carried out under the umbrella of one of the new DRD collaborations. The program is a mix of natural continuations of the current activities and a couple of very innovative new developments, such as a radiation hard embedded FPGA implemented in an ASIC based on System-on-Chip technology. A special and urgent topic is the fabrication of Al-reinforced super-conducting cables. Such cables are a core ingredient of any new superconducting magnet such as BabyIAXO, PANDA, EIC, ALICE-3 etc. Production volumes are small and demands come in irregular intervals. Industry (world-wide) is no longer able and willing to fabricate such cables. The most effective approach (technically and financially) may be to re-invent the process at CERN, together with interested partners, and offer this service to the community

Annual Report 2022

This report summarises the activities and main achievements of the CERN strategic R&D programme on technologies for future experiments during the year 202