RICH detectors will be one key element for hadron identification in future experiments. In most cases, performance improvements and better control of systematic uncertainties will be required, with respect to currently running experiments. Moreover, external requirements might drive the overall detector design, calling for challenging engineering solutions. Therefore, new concepts for implementing the RICH approach are being investigated to satisfy the requirements. This also includes all of the software chain, a key ingredient for the more challenging future experiments.
This WP focuses on the concept, design, feasibility, prototyping, characterization and validation of future RICH detectors, including related technologies, firstly concentrating on projects with expected start date before 2035. The longer term projects like a high-energy electronpositron collider will benefit from the building of knowledge and expertise.
This WP strongly relies on the availability of sensors and their dedicated full readout chain, with known characteristics, as from WP1 and WP2, and will provide detector requirements on the sensors to WP1 and WP2. In fact, the activities of this WP, on one side, and of WP1 and WP2, on the other side, will require continuous reciprocal consultations and information exchange.
Moreover, this WP3 needs some full and flexible enough readout system, from the sensor to DAQ, to be used by imaging array prototypes, both in the laboratory and for test-teams, technological demonstrators, and for the required measurements. Actually, readout electronics is a transversal topic of enormous importance for all this DRD4, which will be coordinated through the WG3 - Technological activities in order to satisfy the different needs. A lively link is also needed with DRD7, exploiting their competence for consultation, but the development of the electronics will be taken care internally to DRD4.
This WP3 also deals with all the thermo-mechanical engineering aspects and it is therefore highly connected to activities in DRD8 and would benefit a lot from their consultation. In fact, an extensive engineering support for detector R&D will be necessary for this WP, in coherence with ECFA GSR 2, in order to take care of the engineering aspects internally to DRD4.
This WP3 has a parallelism with WP4, especially between tasks 3.3 and 4.2. In fact, even though the target detector types are different, RICH-like versus TOF-like, both converge to use photo-detector arrays with similar requirements: continuous reciprocal coordination, consultations and information exchange will be useful to rationalize the work and build synergies.
The timeline, deliverables and milestones are subject to timely availability of the required FTE and funding.
Task 3.1 - New Materials Radiators and Components.
Future RICH detectors will most likely require exploitation of new materials, new radiators and new components, with specific properties, in order to reach the desired performance.
This task deals with the R&D to identify requirements and study and develop the solutions; the methods and tools to characterize materials, radiators and components; the methods and models for measurements and quality control.
• Study of radiator gas alternatives to per-fluorocarbons
• New aerogel optimisation and characterisation
• Exploration of meta-materials as Cherenkov radiators.
• Development of advanced instrumentation and techniques for Cherenkov radiators characterisation, quality assessment and monitoring.
Milestone:
- M3.1: Interim report on requirements for future detectors, survey of possible solutions and definition of the R&D to carry on during years 2 and 3; (M12).
Deliverable:
- D3.1: Report on performance of radiator gas alternatives to per-fluorocarbons; prototype of optimised aerogel radiator module; demonstrator of interferometer for gas refractive index monitoring. (M36).
Task 3.2 - Development of new RICH detector concepts for improved performance
This task concerns specifically the R&D to be carried on during the next three years, targeting detectors with approximately start-date in ten years from now (2035).
It deals with new concepts and detector designs implementing the requirements, validation of design concepts via proof-of-concept or technological demonstrators.
These include the following.
• Feasibility study for a combined RICH/TOF.
• Feasibility study for high-pressure gas radiator-based RICH.
• Feasibility study for use of fast timing in RICH/DIRC.
• Feasibility study for a cryo-RICH.
• Investigation of performance limits of existing technologies (gas detectors, LAPPD).
• Developing new concepts for modular RICH detectors.
Work will be paper-work plus simulations plus technological demonstrators or proof of concepts of the selected concepts.
Milestones:
- 3.2: Interim report on requirements, technological challenges and required R&D to carry on during years 2 and 3; (M12).
Deliverables:
- 3.2.a: Report on feasibility study for new RICH detector concepts for improved performance. (M36).
- 3.2.b: Technological demonstrators and/or proof of concepts of the selected concepts; (M36).
Task 3.3 - Prototype Single-Photon Sensitive Module for Imaging Arrays from sensor to DAQ and self-calibration systems
This task concerns specifically the R&D to be carried on during the next three years, targeting detectors with an approximate start date in ten years from now (2035).
Future RICH and imaging detectors will typically have common challenging requirements, including: suitable radiation-hardness for a large squared meter area, mm-pixelated spatial resolution, O(100ps) time-of-arrival resolution, with large and uniform geometrical acceptance and O(>100MHz) rate capability per pixel. On the other hand, a limited number of specific requirements might be present or missing, for some specific applications. This task has overlap with task 4.2 but has a broader remit covering large area systems using PMT/MCP/SiPM imaging arrays with less of a focus on ultimate time resolution.
The work deals with the following three topics, to be integrated into a single autonomous module of a modular array.
• Prototype rad-hard fast low-noise scalable front-end readout electronics for single-photon counters, see also WG3.
• Prototype single-photon sensitive module for imaging arrays (from sensors to DAQ).
• Prototype systems for on-detector calibration/alignment/monitoring.
The objective of this task includes use/implementation of full readout chains, strongly coupled to both sensors and rest of the detector. It does not include the study of sensors themselves, but only sensors as devices of the imaging array, including all system and integration aspects. The sensors themselves are the subject of DRDT4.1 and DRDT4.2, with which two-way consultation and information is required. It also includes developing suitable on-detector instrumentation to keep systematic uncertainties under control as follows from the typically challenging requirements of future experiments.
PMT, MCP-based imaging arrays are, a priori, included, in addition to SSPD; MCP-based imaging arrays should be considered as well, a priori, as the step following MCP-based sensors validation; PMT imaging arrays, in addition to possible use in future experiments, do exist, are well known and very nicely working and could be very useful for early use in laboratory and test beams as well as for (cross-)characterization of SSPD and/or MCP PMT arrays.
The housing of the sensors is a complex task, regardless of the sensor choice, due to the large number of sensors/channels and the many requirements. The first challenge will be to include some sort of active cooling into the module, together with the other ancillary services, and some sort of radiation-shielding. Combination of different functions into an integrated system is a key goal.
Work will target design, prototyping and characterization of one, or a few, fully functional and autonomous modules of arrays for readout of clusters of PMT/MCP/SiPM, with O(50) ps time resolution and mm size pixelation, including integrated full readout chain, integrated system for self-calibration, integrated local cooling (whenever required) and suitable for tiling a large surface.
The emphasis is on the system level of the design. In fact, the close-packing and integration architecture need to be studied carefully, taking into account the requirements for stability, reliability and low cost. Integration of active cooling capabilities and radiation-shielding would be primary goals.
The collaboration will first investigate requirements, leading to possible different developments, and will decide among options for the R&D as a result of the milestone. The module will used both as a technological demonstrator and as a real detector for laboratory or test-beam studies.
Availability of a suitable full readout system is assumed.
Availability of a sufficient thermo-mechanical engineering support is required.
The task will develop along the following path.
• Phase one:
• survey on available and forthcoming devices (including devices for on-detector calibration), technologies (including radiation-hard electronics and local cooling system) and feed in requirements;
• feasibility study and simulations for use of fast timing readout in RICH detectors.
• Phase two:
• prototype of the readout electronics based on the FastRICH chip, with general purpose readout board suitable for PMT/MCP/SiPM with plug-and-play standard interface to DAQ;
• concept design of the module with a cluster of devices based on existing commercial sensors, fully functional and autonomous, including ancillary system for selfcalibration and local cooling for SiPM;
• executive design and production;
• integration with the readout electronics.
• Phase three:
• test and characterisation in laboratory and test-beams;
• feed-back results into the design;
• technical design report.
Milestones:
- 3.3: Interim report on requirements; survey of possible solutions and definitions of the R&D to carry on during years 2 and 3; definition of specifications for the prototype(s), based on physics; (M12).
Deliverables:
- 3.3.a: Study and design Report. (M36).
- 3.3.b: Prototype of a fully functional and autonomous module of a cluster of Single-Photon Sensitive devices for Imaging Arrays (from sensors to DAQ), including local cooling for SiPM; to be used both as a technological demonstrator and as a real detector for laboratory and test-beam studies. (M36).
Task 3.4 - Study of RICH detectors for future electron-positron colliders
The focus of this task is the conceptual design, and the investigation of the key components, of a RICH detector for a future high-energy e +e − collider, in particular FCC-ee. The physics capabilities of an experiment at such a machine can be greatly enhanced by the addition of particle-identification capabilities. Applications include heavy-flavour studies, and the flavour tagging of jets in Higgs, W, and top decays. These goals imply a momentum range of around 1 to 50 GeV/c, which can naturally be covered by a RICH detector with dual radiators. This detector must be compact, taking no more than ∼20 cm in extent, and low mass, so as not to compromise the other aspects of the experiment’s design. An initial design, the ARC detector, has been proposed, comprising an aerogel and gas radiator, low-mass mirrors and SiPM photodetectors, deployed in an array of cells.
The goals of the task are to optimise the layout of the ARC and investigate other possible solutions. Important challenges involve the possible use of aerogel as a thermal insulator, as well as a radiator, the choice of radiator gas, and whether it must be pressurised, lightweight mirrors, and the need for compact photodetectors with high geometrical efficiency.
Milestones:
- 3.4: Full conceptual design for ARC detector (M12).
Deliverables:
- 3.4: Evaluation of prototype ARC cell (M36).
Task 3.5 - Software and Performance
Future RICH and imaging detectors will face new challenges in terms of events/hits multiplicity, rate, amount of data and background/noise levels, calling for new approaches and/or new implementations to detector simulations and analysis.
Moreover, to cope with future challenges, a number of specialized software tools are necessary, for optimization of specific subsystems, before feeding in the full detector simulation the optimized subsystem. These include tools for optimization, design and performance evaluation such as: CAD for geometrical optics ray tracing, dedicated software for optimization of reflection/anti-reflection coatings and filters, dedicated software for modelling the internal workings of PMT/MCP-PMT/SiPM and for description of photon transport in gases and solids.
Important topics which emerged from the community include the following.
• Development of a common general framework for fast tracing of optical photons.
• Study novel architectures for fast PID in high-multiplicity environment, possibly based on ML and AI algorithm.
• Define agreed benchmarks for optimization, evaluation and comparison of RICH detector performance and systematic uncertainties in simulation/data analysis SW.
• Map and share dedicated satellite SW for studies of specific aspects preliminary to GEANT4- like simulations.
Milestones:
- 3.5: Survey of existing software and techniques and definition of requirements and solutions for the future challenges; (M12).
Deliverables:
- 5.3.5: Establish, develop and make available a common framework for (fast) tracing of Cherenkov optical photons; develop and make available a test-bench/framework for a detector-agnostic software for fast reconstruction in RICH detectors; definition and report on software and performance evaluation benchmarks for future RICH detectors; mapping and evaluation of the dedicated external software tools used by the community; (M36).